Ac Complex Turbulent Flows
Kwlo
Volume I Objetive, Ealuaionof Data, Speili-ctinsc)I T stCases, Discuss!on, ardPosIron,,- Papers
D
V. Ed: fed by
S.J. K';ne.
j
G. '. L i1ey
12
16
Approv(d?ý
097
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READ INSTRUCTIONS BEFORE COMPLETING FORM ACCESSION NO.
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4
THE 1980-81 AFOSR-HTTM-STANFORD CONFERENCE ON COMPLEX TURBULENT FLOWS: COMPARISON OF COMPU-I STATION AND EXPERIMENT-VOIUM1 7.
A jr-oR(a)
SS J
SBJ
,
INTERIM 6.
PERFORMING O-AG. REPORT NUMBER
3.
CONTRACT OR GRANT NUMBER(s)
KLINE.
CANTWELL
F49620-80-C-0027
G M LILLEY 10.
PERFORMING ORGANIZATION NAME AND ADDRESS
9.
STANFORD UNIVERSITY MECHANICAL ENGINEERING DEPARTMENT STANFORD, CA 94305
AREA A WORK UNIT NUMBERS
61102F 2307/Al
September 1980
AIR FORCE OFFICE OF SCIENTIFIC RESEARCH/NA 14.
REPORT DATE
12.
11. CONTROLLING OFFICE NAME AND ADDRESS
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PROGRAM ELEMENT. PROJECT, TASK
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17.
IS. SUPPLEMENTARY NOTES
Proceedings of the 1980-81 AFOSR-HTTM-Stanford Conference on Complex and Experiment, Stanford, CA, Turbulent Flows: Comparison uf Computation. 3-6 September 1980 19. KEY WORDS (Continue on reverse side At necessary and Identity by block mnmber)
COMPLEX TURBULENT FLOWS EXPERIMENTAL DATA ATTACHED BOUNDARY LAYERS "SEPARATED FLOWS 'TWO-DIMENSIONAL FLOW
THREE-DIMENSIONAL FLOW
20. ABSTRACT (Continue, on reverse side If nec.4.ery and identify by Maock nmiber)
Thisvolume contains the Proc edings of the 1980 Meeting of the 1980-81 AVOSR-HTTM-Stanford Conferenýe on Complex Turbulent Flows: Comparison of Computation and Experiment.,&he Conference includes two meetings. The first, -rted-here,,nhad the goal of establishing a data base of -Uet cases9 for comparison with computations. This volume contains a record of the proceedings of the 1980 meeting and a display of the test cases used in the 1981 meeting The main sections of the volume include: for comparison with computations.
DD
,
1473
.y/~OITION OF I NOV 65 IS OBSOLETE
UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE ("hen Dare Entered)
SECURITY
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.11)Pictorial summary charts providing a compact picture of the nature of the test cases. (2)-.,fntroducticn: The history and nature of the Lonference. (3,ýThree position papers covering: (a) data needs for computational fluid dyneumics; (b) sotac improvements to the theory of upcertainty analysis and theuse of that theory for the present Conference;, (c) description of Data Library. (ý) Description of test cases including: &samnary; discussion;
specifications for cornputations;! output plots for the test cases. (5)-'. 'Reports of ad-hoc committees on topics of general interest; general discussion; and conclusions. )Index to Flow Cases.
(6) Lists oft Participants, Data Evaluators;
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COM.',EX TURBULENT
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[Com utation•
THE 1980-81 AFOSR-HTTM-STANFORD CONFERENCE ON COMPLEX TURBULENT FLOWS: COMPARISON OF COMPUTATION AND EXPERIMENT VOLUME I --
OBJECTIVES,
EVALUATION OF DATA,
SPECIFICATIONS OF TEST CASES, DISCUSSION AND POSITION PAPERS Proceedings of
the 1980 Conference
Stanford University,
Stanford,
September
"Edited by
S.
J.
Kline,
B.
J.
3-6,
California
1980
Cantwell,
and G. M. Lilley
Published a.d Distithuted by Tlhernosciences Division Mechanical Engineering Department Stanford University Stanford, California
•:,
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k~~~~~~~.Apr.rov.. -.. ...
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Editors
Stephen J. Mechanical
Kline Engineering Department
Stanford University Stanford, CA 94305,
USA
Brian J. Cantwell Department of Aeronautics and Astronautics Stanford University Stanford, CA 94305, USA Geoffrey M. Lilley Department oif Aeronautics and Astronautics University of Southampton Southampton S09 5NH, England
Production Editor and Conference Secretary: Ditter Peschzke-Koedt Palo Alto. CA 94301, USA
ISBN. Cc)
1981 by the Board of Trustees of the Leland Stanford Junior University. All rights L.C.
reserved.
?rinted in
the United
Stats of America.
81-0908
Stanford,
California, USA 94305, (First Printing)
1981.
'-4
•-, .".
.
.
-
.
.
•
.
....
ACKNOWLEDGMENTS The
Conference
the
fullest
and generously Evaluators, of
ipation
given.
Session
France,
india,
of America, The by the a
Air
tributions
were
grant.
is
was
critical
Naval
to
u;seful
grew
crease
in
cost, and
purposes
were
Program
of
Dr.
also
Funds to cover
the by
impartial-
and engineering communities
was sought
are extended Recorders,
from
process
with
been held.
to all
the Data Takers,
whose names appear
The 1980 Conference
Norway,
was
Switzerland,
]
Data
the
List
1
attetded by
Canada,
(Australia,
Sweden,
in
their help and partic-
Without
14 countries
Scientific
England,
United
NASA Ames
the
of
The
States
J
,'$
the
steadfast
spent
secure
the
much
funds
from
the
to
by
of NASA,
Foundation.
the
specific to fund-
support
of AFOSR
of
Dr.
James Wilson
When the volume of cases a
to
resulting
organize
complete
Heat
Centers
Con-
The
with
effort
NAG 2-79.
Bushnell of NASA with regard
Science
the work.
Transfer
and
found
concerned
Funds
for
Turbulence
I A
to be
and considerable
the
-W
of compressible
under Grant
Research
National Dennis
estimates,
Wilson
Center
supplied
AF F49620-80-C-0027
processing
on data
and Lewis
the Conference.
initial
supplied
work
Research
Langley
and by
conference was
this
Research under contract for
support
the
the work of
for
Rubesin and Dr.
success
thereby
the
•
Research
beyond
the Conference
this volume.
in
sponsorship
acknowledged.
the
far
agencies
by
Morris
gratefully
thanks
learning
a cooperative
the aims of
Netherlands,
Added
also made
Dr.
as
and Yugoslavia).
supplied
of
Office
ing
Japan,
Force OffLce of
was
viewed
and Technical
financial
predecessor
assistance of
special
participants
West Germany,
U.S.
To achieve
could not have
invited
principal
best
1980 Conference
Israel,
flow cases
U.S.
Our
to the
160
is
of the scienttfic
Chairmen,
the Conference
approximately
"-. "p.
cooperation
Participants
and
a whole
as
the research community.
within ity,
1980
in-
government
some
special
Mechanics
(HTTM)
Industiial Affiliates Program of the Stanford Thermosciences Division. p] an overdraft in the base contract were generously supplied by the Stan-
ford School of Engineering. Special B.
Bradshaw, who
thanks
worked
personnel
J. long
are accorded
and
problems.
Host
confercnqp
Committee,
The
students
who
of
who
served
made as
and
J.
i-.
Ferziger
beginning
ingredients
this
sort all
thanks. for
in
1977
J.
Kline
on
the
plans,
and enthusiasm
of
(Chairman), and G.
Sovran,
organization,
the members
P.
and
of
this
the success of the Conference. have
local
been held without
arrangements,
Recorders
and Aides
Special appreciation
important
S.
M. W. Rubesin,
Reshotko, in
confidence
would
the
Technical
E.
Launder,
continuing
these we add our grateful ston
E.
thoughtfully
committee were important No
B.
Cantwell,
the Organizing Committee:
assistance
iii
in
and
the
(see
list
is
the willing help of many
Stanford
on page
giver, to Profs.
studying
data
graduate
607); J.
the
to all P.
and closing
Johnmany "'U
Professor J. K. Eaton organized the aides .'md
special gap-5.
ýupcrvtscd all
physi~cal
Professors W. C. Reynolds and R. J. m.,-Eat lent
arrangements in a very able fashion.
the support of the Thermosciencee Division and the Department of Muchanical Engineering qý important Poniits.
?rofessor M. V. Morkovin acted as a senior advisor on many
isasues. The arduous and critical task of recording the data on magnetic tape the
students
L
-B-ardina,
La
was
graphs
files
and
preparing
under
the
djirection
data
of
handled
13.J. Cantwell
by
a cadre
includ~iig:
of
organizing
Stanford graduate
Jalal
Abhjace,
Bob Carella, Aim McDaniel, R~anga jayaranan, Charles Natty, Ken Schultz,
Juan Tony
Strawa, R~am Subbarao, and Jim Talleghani,
The Conference waa fortunate in having the aid of a very able secretarial staff. is needed
Particuli~r
praise
typing and
for the
responsible fashion. Thompson and
For
flitter
organization of
Peschcke-Koedt,
who ',as responsible
for all
the paperwork system in a highly independent
and
Thanks are also due Barbara ;1omsy, Ann Tbaraki, Ruth Korb, Diana
Anne Voilmay?r,
for various secretarial duties and for their enthusiapm
and support. We are also
indebted to Professor S. Honami
torial. summaries known informally as
for his work in producing the
the "Honami Charts" and to Prof.
pic-
D. J. Cockrell
for special assistance in preparing documents and other matters during the period just before the 1980 meeting of the Conference.
iv
d
PREFACE This
volume
HTTH-Stanford Experiment.
September base of
addition,
the
USA
(ii) "
accurate
the
two
goal
the
Flows:
meetings.
this
of
the
first
output
of
cases
in
building on
and
The
first,
the of
other
with
Department of Mechanical
herein,
the test
flows
models and or
Computation
the establishment
library on magnetic
proceedings
AFOSR-
The second meeting,
computations
certain
1980-81
reported
meeting was
computer
the
of
Comparison
with computations.
test
Information
1980 Meeting
the
tape
deemed
cases. in
Engineering,
was of
a
held In
permanent
sufficiently
testing output data
and
in
com-
library can be ob-
Stanford,
California,
94305. This volume has
tvo
to
test
display
the
purposes: cases
(i)
to record
that will
the proceedings of
be used in
the
the 1980 meeting;
1981 meeting
for
comparison
The volume has six major elements:
I.
Pictorial summary the test cases.
2.
Introduction:
3.
Three position papers covering: (a) Data needs for computational fluid dynamics; (b) Some improvements to the theory of uncertainty analysis and the use oL that theory for the present Conference; (c) De=cription of Data Library.
4.
Description of test cases including: summary; discussion; "tions for computations; output plots for the test cases.
5.
Reports of discussion;
6.
Lists of Participants,
The l
Introduction,
Boundary
"*
includes
for use
flows.
Turbulent
for comparison
from the editors at
cluding
and
Complex
the
of
has established a data
holds
with computations.
.
Proceedings
compares
Conference
turbulent
tained
1980;
1981,
library and
on
Conference
3-6,
14-19,
the
the
"test cases"
September
plex
-
The
data
complete .
Conference
held
form;
contains
Free
the
earlier
Layccs and Shear
"The
ad-hoc committees and conclusions.
by S. 1968
the
Layers,
deeply
a compact
on
topics
Data Evaluators; J.
Kline,
of
picture of
the nature
of
general
the
The
involved
in
computational the
on
general
the
Conference
Computation
also
of
in-
Turbuleult
boundary Layers
discusses
the
problems
and the special procedures employed the 1980 meeting of the Conference.
fluid dynamics
preparatory
of
on Compressible
Introduction
the present Conference preparatory work and in
interest;
history
Conference
1969 and 1972 NASA Conferences respectively.
specifica-
Index to Flow Cases.
summarizes
AFOSR-IFP-Stanford
paper on data needs in all
providing
The history and nature of the Conference.
that arose which led to both in the two-year-long
viduals
charts
work,
P.
is the work of Bradshaw,
B.
J.
six indiCantwell,
V .
.
...
•
.
°
J.
H.
Ferziger,
S.
J.
Kline,
M.
R.
Rubesin,
and
C.
C.
Horstman.
The
first
four
authors worked
on the draft seriatim followed by several iterations concerning differ-
ences
P.
between
conditions.
The
which have ferences
Bradshaw final
two
The
made
on
questions
independent It
paper on the data
library;
the author
in
the
by one
Sources
on
case on
and
boundary
compressible
to note
flows
that somse dif-
remains among the authors. the paper
Since
should be widely use-
further clarifications.
the n.ture,
function and
the
nomenclature
the central responsibility
for distribution of current
Each
numerics
is important
Cantwell has assumed
paper.
of information. followed
library describes
B. J.
are
provided
over time, to still
of
comments
to have appeared before,
lead,
the library.
is
Ferziger
for completeness.
seems
struction of
files
H.
regarding the best statement of needs still
and will hopefully
the
J.
authors
been consolidated
no paper on this topic ful,
and
magnetic
for con-
vcrsions of the library
tape
consists
of
two
or
more
File I contains a detailed description of the given case.
or
more
files
of trormalized
data.
of
A sample
File
1 is
This
included
in
this paper. The tant
paper
topic that
uncertainties
seems
in
computation; In
on uncertainty
are,
attention,
data
in
Moffat
order has
uncertainty advances are
of
germane
plots
are
were
for
1981 meeting were
cases
discussion
the
data
but are
and
When
are
:
be
with
paper
of
significant,
properly
sustained
Moffat
from
in
and ape-
the
important
in
the
R.
J.
area of
conceptual
The advances
many
in
1968.
interpreted.
interest
contributes
data
in
the uncertainties
Kline and McClintock).
used
imply
selected
but
size.
also
for
a case
presented.
necessarily
of manageable
future work,
Individuals
the comparison
displayed.
does
of
to the uncertainty
were not needed
on eotimates of
impor-
the 1968 meeting the
small compared
of data uncertainty
focused
present
accepted
and
the
In
of each test case follow
meeting
pleteness
the
to
summary
not
some circles.
discussion an
by Moffat
laboratories,
and
thus
of the current voliue.
presentaticns
Wlen cases
for
with computatic
few
in
form a logical portion
output
to be
the older standard (of
particularly
ing.
the
analysis.
beyond
The
had
that comparisons one
in
re-opens
the data uncertainties are frequently
therefore,
been
and
for the most part,
special considerations
the 1980-81 Conference,
cial
extends
to have been neglected
the data
thus
annlynio
any
the
was
The
the order and
not
lack
in
order
to
meeting,
used
failure
not only on
in
1981
to
in
in
the 1981
test
of
and
1981
the
meeting, case
the data;
in
in
the
complete
only the
final
trustworthiness
reasonably
cases.
1980 meet-
the specifications
a given
basis of
form a
Some test eases will be stored
not employed
the
use
qua!ity the
format of the
set
1981 cases
ane comof
test
the lihrary as usable for
The
library
index will show
such flows. The the
specifications
1980 meeting
where
for
computations
they were
given
are in
not
displayed
a variety
in
of written
the
form
(rather
presented than
in
tabular)
I7
forms. dard
All
specifications
tabular
formity have
of
form to provide
presentation.
been
excessive
either
nmber
plots.
of
some
short
The
data
time,
noted
above,
interest
procedure
is
to focus,
not only what is
in
some
community
of
the
order
by
Division
of
with
the
are
of
the
data
should
is
evaluators,
Volume
S.
J.
year later. the
art,
The
important
in
the
an
with
the
a relaplots
Introduction;
differences well
requires
to the
from
further
they
the usual
as agreements
in
order
researches.
remain vexing to the
reliability
of data.
Several
of
for future data takers.
appears
appear at
in
two
places .
of
this
the end
each specification.
Honami,
while
Engineering
he was
A complete set
section.
Separate
These charts a
Department
visitor at
to
Stanford
were
the in
ini-
Therrao1979-80.
the volume who assume responsibil-
from notes made during
to
within
in
the
future.
by
G. M. to
class,
past Hence,
Of
future data a
are
a
rich
phsec ard
particular
takers."
that
in
in
number most
for anyone
the the
comments
large
can and
source
note
The
surprisingly
procedures
they
preparatnry
Lilley.
include
data
the
by of
cases
planning
flow situations.
Evaluation
of
Data,
presented here.
three volumes
time of publication.
flow of
Conc-isions,
including both
and
the "advices
each
on related
I--Objectives,
Methods,
of
Lo avoid
rests
1981 covering needed changes.
recorded
by the editors of
Kline,
sion and Position Papers--is
*
or
specifcatLionM
of opinion as
flows
with
Mechanical
difficulties
be avoided
the
Shinji
the reference
indicating
files,
for a variety of reasons,
flows
were drawn
by
future experiments
Somies,
file)
deletions
the final copy.
conclusions primarily
data
The
respect
of
included
Professor
ity for any errors in
remarks
data
evaluators
include discussion by an unusuatly large gather-
that,
Final editing has been completed
conclusions
meetings.
summary charts
charts
prepared
the
(in
by data
and uni-
At !cast one Cormputor group was asked to
should make uaeful contribut!ons
numerical
meeting,
requested
these
but also what still
topics
particularly
pictorial
The
for
procedures are
committees
on
between
of differences
known,
of ad-hoc
leading experts
these reports
*-
lacking
with plots,
into the present volume.
future
the recordatton
The reports
sciences
plots
errata were issued early in
the discussion
may be of
tially
were
to Computers.
These errata have been incorporated
the
few
to a stan-
and
and
in
a
responstbility
discrepancies
difficulties
sectors
clear coincidence
editors
some
report such
The
by the
in
releaues
research
convurted
large variety of flows and the amount of data processed
the first
ing of
claritLy,
instances
because
in
As
were
Committee of the Conference.
Because of the
occurred
Increasud
In
eliminated
Organizing
tively
for computations
and
Outpu..
Specifications
Test
Cases,
Discus-
The companion Volumes 11 and lIl--Taxonof
should form a
of
Compu-ations
will
relatively complete
the accomplishments
and
Unlike the 1968 Conference,
appear
roughly
picture of
the
a
state
the remaining difficulties,
at the
which largely completed
a chapter of
vii
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I reseatch work, computation. done
and
an
direction
"The is
present
improved
it
picture of
editors of
teer
fortunate
individuals, efforts of
critical
CompleLe
potential
remaining
needs.
the
needs
users with it
should
test case.
to coot.Mnate. and has
In out
These data evaluators new
The
only been
the participants
performed
to emphasize
effort of a large
role has been carried
but also
will not
provide
th!s volume also wý.nt
rather a cooperative
few
conference abould
a
for eil-her key
data or
to what
also provide
a
can he clearer
for future research.
have been a
the
fowevrt,
iuncttons
by
nc
that the work is
not theirs;
fraction of the research community, task is
possible
and was too through
the willing
the 1980 meeting and, the
data
evaluators
,nly assinilated
not unders:ood
large
hence,
any one or even
and largely volunin
this volume,
th:
whose names appear on each
and
evaluated the literature,
req,,ested at
or
foi
it
which ve
the outset.
It
is
largely owing to the efforts of the data evaluators that this volume has become possible.
S
3J: K1 in P
B.
J.
Cantwell.•:
G. M. Lilley JuLy
1981
viii
-_-.
--
--
-
.
"-.
-
.
,.
...
- .
. .
...
"
-
-..
--.-
.
-:
-.
"
.
.
TABLE OF CONTENTS
Acknowledgments . .......... . Preface . . General Committees . ........... ................ xv Program: 1980 M'eeting on D;tto . ........ )CVJ General Nomenclature .. ........................................................ xx Pictorial Summary .. ......................................................... xxiii INTRODUCTICN (S. J. Kline) ...................................................... POSITION PAPERS
EXPEKIMENTAL DATA NEEDS FOR COMPUTATIONAL FLU'ID DYNAMICS --A POSITION PAPER (P. Bradshaw, 3. J. Caniwell, J. H. Ferziger, and S. J. Kline wtth imnlents by M. Rubesin and C. Horstmar.). ..............
23
CONTRIBUTIONS r0 THlE THEORY OF UNCERTAINITY ANALYSIS FOR SINGLE-SAMPLE EXPERIM4ENTS (Robert J. Moffat)..................................40 THE DATA LIBRARY (Brian Cantwell)...................................................57 O~~igcussior. o' The Data Libray..................................................79
I
SESSION I Flow 0610,
At-.ached
Boundary Layers
Summary...............................................................86
Specifications .. ............................................... 83 Flow 0210, Effect of Free-Stream Turbulence on Boundary Layers Summary. .. ..................................................... 82 Discussion .. ................................................... 91. Specifications .. ............................................... 93 Flow 02.30, Boundary Layer Flows with Streamwise Curvature Suimmary. .. ..................................................... 94 Discussion .. ................................................... 96 Specifications .. ............................................... 98 SESSION I1
Flow 0240, Turbulent Bolindary Layers with Suction or ",lowing (Incompressible) Flow 8300, Turbulent Boundary L-ayers with Suction or Blowing (Compressible) Summary .. ...................................................... 112 Discussion. .................................................... 117 Specifications. ........................... ...................118 Flow 0330, Free Shear Layer with Streamwise Curvature Suniinary .. ...................................................... Dlscission. .................................................... Specifications. .............................................
ix
owl
130 133 134
-
Page Flow 0510, Turbulent Secondary
j
Flows of the First Kind ... .. ..
139 145 146
.........................
..
162 168
........................... ......................... .......................
... .. ...
170 174 176
... ..
178 180
........................... ......................... . ......................
Summary .............. Discussion ............. Spectficationu ...........
I
SESSION III Three-Dimqnsional Turbulent Boundary Layer
Flow 0250,
Summary ........................................ Discus ton ............. Planar Mixing Layer
Flow 031C,
Summary .............. Dits-,sston ............. Specifications. ..........
Flow 0150, Two-Dimensional Channel Flow with Periodic Perturbations ........................... .........................
Summary .............. Discussion .............
-
SESSION IV
.
Flow 0110, Corner Flow Data Evaluation (Secondary Flow of the Second Kind) ... ........................... Summary .............. ......................... Discuasion ....................... .......................
Specifications ...........
182 188
..
189
..
213 217
...
218
..
218
Entry Zone of Round Tube
Flow 0130,
........................... Sumr.ary ........................ Discussion ............. ......................... NUMZRICAL CHECKS (E.
Reahotko) ..........
....................... .
Discussion .............
........................
1
SESSION V Flow 0410,
Fvaluation of Bluff-Body, Summary
.
Near-Wake Flows
........................
.
Dtsr'iss I.................. Specifications ........... Flow 0440,
......
220
226 227
L
Two-Dimensional Stalled Airfoil ........................... ......................... .......................
Summary .............. Discussion ........... Speciticiitlons ........... Flow 0140,
....................... .......................
Diffuser Flows
'Unseparated; and Flow 0430,
Suumary .............. Discuss!on ............. Speri(icatio,,ub ...........
... .. ...
234 246 247
Diffuser Flows--Separated
........................... ......................... .......................
... ... ..
253 258 259
Y • •
.
: . •-- 2=.:• -•, ::. .i -
.:2
. - .- ,-,- - -.. ..
=. .
.-" . - - -.-.
"
" - =,
. ..
i
'
,i -l
"
i
-"
.
"
*..4
,;
- " " " . ..
"
"
"
SESSION VI Flow 0420,
Backward-Facing
Step Flow
Summary ................. Discussion ................ Specifications . . . . . .
........................... ......................... . . . . . . .
AN OVERVIEW OF THE PREDICTIVE TEST CASES (J. Case P1,
Flow 0110,
Asymmetric Flow in
.
K. Eaton) ...
.
.
.
.
.
.
.
.. .. . .
275 280 281
..
284
.. ..
287 269 290
.
297 299 300
...........
a Square Duct
Summary ................. ........................... Discussion ........................ ......................... Specifications ............... ....................... Case P2,
Flow 0420,
Backward-Facing Step: Variable
Opposite-Wall Angle
Summary ..................................... Discussion ................ ......................... Specifications . . . . . . . . . . . . . . . . Case P3, Flow 0420, Backward-Facing Step: Turned Flow Passage
.
.
.
.
.
Summary ................. ........................... Specifications ............... ....................... Case P4,
... ..
301 303
...
304
Flow 0420,
Backward-Facing Step: Variable Area Ratio Summary ................. ........................... Specifications
Case !y, Flow in
...............
.......................
a Planar Diffuser with Tailpipe ......
Cahe ?6, Shock-Boundary Layer
Interaction .........
Discussion ........................ Case Pe
.
Transonic Airfoil ............... Discussion ................ Discussion,
Flow 9000,
305 ..............
.................
..
310 31l
... ..
......................... Cases .....
............
312 312 313
Flows with Buoyancy Forces Summary ................. ........................... Discussion ...... .........................
Flow 0340,
306
.........................
.........................
General Predictive
..
...
314 316
Flows with Swirl Summary ...................
...........................
..
317
SESSION VII Flow 0360, Wakes of Round Bodies, and Flow 0390, Axisymmetric Boundary Layer with Strong Streamwise and Transverse Curvature Summary .i............. ......................... Discussion ........................ ......................... Specfications ....................... ....................... Flow 0380,
Wakes of Two-Dimensional
.
3327 331 332
Bodies
Summary ................. ........................... Supplement to Summary ........... .................... Specifications . . . . . . . . . . . . . .
.
.
.
.
.
.
.. .. .. .
340 346 356
xi
.2
M
*Flow
Summary . . Discussion
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
Specifications .............. -'
Flows 8100/8200,
Supersonic
Flow over a
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
(Insulated/Cooled
364 366
..
36'
... .. ..
369 374 375
...
378
..
388
..
393
. .
Lu an
...........................
Summary .................
. .
. .
Wall)
........................... ......................... .......................
Flows 8400/8410, Boundary Layers In an Adverse Pressurc Cr~di!ent Adxsymmetric Internal Flow/Two-Dimensional Flow
....................
Supplement to Summary .........
.........................
Discussion ................ Specifications ..............
'
. .
.......................
Flat Plate
Summary ................. Discussion ................ Specificattons ..............
*
* --
Page
8500, Compressibility Effects or Frý:e-Shear Laer
.......................
394
SESSION VIII -
Flow 0370,
Romogeneoun
Turbulent
Flows
Summary... .........
. . .........................
Flow 0260,
Turbulent Wall
405
...........
411 412
......................... .....................
Discussion ........................ Pictorial Summary ............. Jet
Summary ................. Discuosion ................ Specifications ..............
........................... ......................... .......................
... .. ..
434 443 444
... ..
458 465 466
... ..
482 484
SESSION IX Flows 8610,
8630,
8640,
Compressible
Flows Over Deflected
SLmmary ................. Discussion ................ Spe-Aficattons ........................... Flow 8680,
Axisymmetric Near-Wake
Surfaces
........................... .........................
Flow (Supersonic) ........................... .........................
Summary ................. Discussion ................
SESSION X
Flows 8650, 86b0, 8600, 8690, Shock Wave--Boundary-Layer Interaction Flows Summary ................. Discussion ................ Specifications ..............
........................... ......................... .......................
.. .. ..
486 495 498
.. .. ..
523 530 531
SESSION XI Flow 8620,
Transonic A.irfoils Summary ................. Discussion ................ Specifications ..............
_
........................... ......................... .......................
xii
#t,:.•.,•.
,
•,
-
-
•
"
..
--
.
.'- --
-
L"
Flow 8670,
Pointed Axisymmetric Bodies at Angle of Attack (Supersonic)
..
543 546 547
... ..
549 549
........................... .........................
... ..
551 551
...........................
...
552
........................... Summary ................. ......................... Discusnion ........................ ....................... "Specitications ..............
...
Flow 8310, Variation in Cf/Cfo for Blowing/Suction with Mach Number Summary ................ Discussion ................
........................... .........................
SESSION XII Transient Flows Summary ................ Discussion ................ Flow 0350,
Ship Wakes Summary .................
Flow 0290,
Laminar-Turbulent Transition Summary
554 554
............................
"Discussion ............................... Flow 0470, Flow Over the Trailing Edge of Blades and Airfoils ........................... Summary ............... ......................... Discussion ................ -Specifications ............... ........................
... .. ..
555 558 559
... .. ..
567 571 573
Flow 0280, Relaminarizing Flows ........................... ......................... ....................... Specifications .............. Summary ...............
"Discussion ................
SESSION XIII
"Ad-Hoc
-
Committee Report on Hot-Wire Anemometry at Low Mach Numbers ... .....
583
Ad-Hoc Committee Report on Use of Hot-Wire Anemometers in Compressible Flows
586
Ad-Hoc Committee Report on Free-Shear Layers .....
...
588
Ad-Hoc Committee Report on Turbulence Management and Control of Large-Eddy Structure ................... ............................... ...
590
Closing Discussion on Reports from Ad-Hoc Committees ...
...
591
...
592
Closing Discussion on Sessions I Through XII. ..... Report of the Evaluation Committee
.
.
................
............
................
595
...................
SESSION lIV
"Plans for
1981 and Beyond ..............
.........................
xiii
..
596
CONCLUSIONS
605
.
LIST OF PARTICIPANTS
607
.*
GROUP PHO'fuGRAPIIS A AND B. LIST OF DATA EVALUATORS.
.....................................................
618
.......................................................
NUMERICAL INDEX OF FLOW GASES AND DATA LIBRARY TAPE ..
xiv
622 .........................
624
471
S.J.
B.E.
I
Kline
E. Reshotko
Launder GENERAL COMMITTEES
B.J.
Cantwell
M.W.
Rubesin
Organizing Committee__ Stephen Kline, Stanford University,
Chairman
Peter Bradshaw, Imperial College, London Brian Cantwell, Stanford University Brian Launder, University of Manchester, Manchester Eli Reshotko, Case-Western Reserve University Morris Rubesin, NASA-Ames Research Center Sovran,
Gino P.
General
Motors Research
A
Laboratories G. Sovran
Bradshaw Evaluation Committee, H. D. R. P.
M. V.
W. Emmons,
Harvard
1981 Meeting
llniver'sity,
Chairman
Chapman, NASA-Ames and Stanford University G. Hill, University of British Columbia G. M. Lilley, University of Southampton Marvin Lubert, General Electric, KAPL Morkovin, Illinois Institute of Technology W. C. Reynolds, Stanford University P. J. Roache, Consultant J. Stegev, Stanford University Host Committee at Stanford Brian Cantwell John K. Eaton Joel H. Ferziger James P. Johnston Stephen J. Kline Robert J. Moffat William C. Reynolds
xv
"".. ;
. -.
.
.
¾
,
.
.
"
"~-.
.
-
.
A>
-
PROGRAM:
1980
MEETING
ON
DATA
THE 1980-81 AFOSR-HTTH-STANTORD CONFERENCE ON COMPARISON OF COMPUTATION AND EXPERIMENT COMPLE: TURBULENT FLOWS:
8:30-8:50
8:50-10:00 am,
SESSION I
Chairman: V. C. Patel Technical Recorders: R.
September 3,
Wednesday, Subbarao,
1980
Parikh
P.
Present and Future--B.
Past,
Cantwell
8:50-9:15
(1)
The Data Library:
9:15-9:30
(2)
Flow 0210: Effect of Free-Stream Turbulence--P.
9:30-10:00
(3)
Flow 0230:
Coffee & Refreshments
10:30-12:00 noon,
B. Launder Chairman: Technical Recorders: 10:30-11:10
(1)
Flow 0240:
11:10-11:35
(2)
Flow 0330:
11:35-12:00
(3)
Bradshaw
Boundary Layer with Streamwise Wall Curvature -- T. Simon/S. Honami
10:00 -10:30 SESSION II
Kline
and Procedures--S.J.
Framework;
Goals,
INTRODUCTION:
September
Weduesday,
R.
Childs,
P.
3,
1980
N. Joubert
Boundary Layers with Blowing/Suction -- L. C. Squire (E. P. Sutton)
Free Shear Layer with Streamwise Curvature -- '. Bradshaw Flow 0510: Pressure-Driven Secondary Flow--R. B. Dean 12:00 -1:30
SESSTON 111
1:30 -3:00
Chairman:
J.
P.
pm,
Lunch 3,
September
Wednesday,
1980
Johnston
Technical Recorders:
E.
Adams,
I.
P.
Castro
Boundary Layers--D.
1:30-2:10
(1)
Flow 0250: Three-Dimensional B. van den Berg
2:10-2:35
(2)
Flow 0310: Planar Mixing Layer--S.
2:35-3:00
(3)
Flow 0150: Channel Flow with Superposed Waves--M. 3:00-3:30
SESSION IV
3:30-5:00 pm,
Birch Acharya
Refreshments Wednesday,
September
W. C. Reynolds Chairman: A. Cutler, Technical Recorders:
3,
A.K.M.F.
1980 Hussaiin
3:30-4:10
(1)
Flow 0110: Entry into a Rectangular Duct--F.
4:10-4:35
(2)
Flow 0130: Entry Zone of Round Tube--J.
4:35-5:00
(3)
Numerical Checks--E.
Reshotko
xvi
SoA
Humphreys/
Gessner
B. Jones
*1
PRLJRAM:
1980 MEETING ON DATA
SESSION V
8:30 -10:00
am,
Thursday,
September 4, 1980
=I
Chairman: A. Roshko Technical Recorders:
A.
Strawa,
H.
L.
Moses
8:30-8:55
(1)
Flow 0410:
Circular Cylinder and Related -- B. Cantwell
8:55-9:20
(2)
Flow 0440:
Stalled Airfoil--A.
9:20-10:00
(3)
Flows 0140 and 0430: Diffuser Flows--R. 10:00 -10:30
Bluff Bodies
Wadcock L.
SimpRon
Coffee and Refreshments
10:30-10:55
(1)
Flow 0420:
10:55-11:35
(2)
Predictive Cases:
Backward-Facing
Step--J.
I
K.
Eaton
Organizing Committee
0 Discussion of Procedures * Specification of Geometries, (3)
Initial
12:00-1:30 Lunch 1:30-3:15 pm, Thursday,
Chairman:
L.
:1
Conditions
Report on flows with Buoyancy Forces--J. Report on Flows with Swirl--A. Morse
SESSION VII
I "
SESSION VI 10:30 -12:00 noon, Thursday, September 4, 1980 Chairman: E. Reshotko Technical Recorders: R. Westphal, D. J. Cockrell
11:35-12:00
i
Wyngaard
September 4,
1980
W. Carr
Technical Recorders:
B. Afshari,
F.
A.
Dvorak
1:30-2:10
(1)
Flow 0360 Flow 0390
Subsonic Axisymmetric Wake--V. C. Patel Boundary Layer with Strong Streamwise and Transverse Curvature--V. C. Patel
2:10-2:25
(2)
Flow 8500:
Spreading Parameter a for Mixing Layer as a Function of Mach Number--P. Bradshaw
2:25-2:45
(3)
Flows 8100 and 820C
.
Cf/
Variations in Cf/Cfo with M and Tw /T 0 •--M. Rubesin/C. Horstman w 2!45-3:15
(4)
Flow 8400 (8401, 8402, 8411) Compressible Boundary Layers Flows--H.
(5)
Case 8403
Compressible
3:15-3:30 SESSION VIII
Chairman: Technical
L.
Lilley
1
Refreshments
3:30-5:00 pm,
J.
Boundary Layer Flow--G.
Feraholz
Thursday,
September 4,
1980
Lumley
Recorders:
S.
Pronchick,
H.
Nagib
3:30-3:50
(1)
Flow 0370:
3:50-4:30
(2)
Flow 0260: Wall Jet--B.
4:30-5:00
(3)
The Control of Accuracy via Uncertainty Analysis -- R. J. Moffat
Sheared Homogeneous Turbulence--J. Launder/W.
H.
Ferziger
Rodi
"xvii -
N .
.
.
.
..
.
.
.
.
.
.
PROGRAM:
1980 MEETING ON DATA
8:30-10:O0
SESSION IX
Chairman: S. Bogdonoff Technical Recorders: P. 8:K0-9:30
(1) (2) (3)
9:30-10:00
Eibeck,
10:00 -10:30 SESSION X
Favre
Coffee & Refreshments
10:30-12:00 noon,
September 5.
Friday,
1980
R. So
Flow 8650: Axisymmetric Shock !-plngement (High Supersonic)--'-. Kubesin/C. Horstman Flow 8660: Three-Dimensional Shock Impingement (Supersonic) -- H. Rubesin/C. Horstman Flow 8600: Impinged Normal Shock Wave, Boundary Layer Interaction at Transonic Speeds -- M. Rubesin/C. Horstman Flow 8690: Non-Lifting, Transonic Airfoil, Shock-Separated -- M. Rubesin/C. Horstman
(1) (2) (3)
(4) 11:30-12:00
Morel
Supersonic Near-Wake Flow--A.
Chairman: J. McCroskey R. Strawn, Technical Recorders: 10:30-11:30
T.
5, 1980
Flow 8610: Transonic Flow over a Bump -- M. Rubesin/C. horatman Flow 8630: Two-Dimensional Compression Corner--C. Horstman Flow 8640: Reattaching Planar Free-Stream Layer (Supersonic)--M. Rubesin/C. Horstman Flw 8680: Axisymmetric,
(4)
September
Friday,
am,
Data Needs for CFD--Discussion of Draft--Participants
(5)
Lunch
12:00 -1:30 SESSION X1
1:30-3:00 pm,
Friday,
Septembeý
P. Bradshaw Chairman: R. Carella, Technical Recorders:
J.
5, 1980
A. C. Humphrey
1-.30-2:10
(1)
Flow 8620: Transonic Airfoils--R.
2:10-2:40
(2)
Flow 8670: Pointed Axisymmetric Bodies at Angle of Attack (Supersonic)--D. Peake
2:40-3:00
(3)
1low 8300: Variation in Cf/C -- L. C. Squire (E. P. Sutton)
with Blowing
Refreshments
3:00-3:30 SESSION XII
Melnik
3:30-5:00 pm,
September 5,
Friday,
P. S. Klebanoff Chairman: M. Lee, Technical Recorders:
J.
1980
Gerrard
3:30-3:50
(1)
Status of Unsteady Boundary Layer Experiments -- An International Review--L. W. Carr
3:50-4:00
(2)
Flow 0350: Ship Wakes--V.
4:00-4:10 4:10-4:30
(3) (4)
4:30-5:00
(5)
Flow 0290 Laminar-Turbulent Transition--E. Reshotko Flow 0470: Flow over the Trailing Edge of Blades and Airfoils--P. Drescher Flow 0280: Relaminarization, Laminarescent and RetransirtR. Sreenivasan ing Boundary Layers--K.
C. Patel
xviii
*
*
*..
i"
PROGRAM:
1980 MEETING ON DATA
SESSION KII
8:30-10:00 am,
Saturday,
Chairman: J. B. Jones Technical Recorders: R. Reports
8:30-10:00
from Ad
September 6,
Westphal,
P.
1.980
Moin
h1oc Committees on Basic Questions;
Revisions of Specifications
Coffee & Refreshments
10:00 -10:30 SESSION XIV
10:30-12:00 noon, Saturday,
Chairman: G. Sovran Technical Recorders:
R.
Jayaraman,
September 6,
1980
G. Lilley
0
Plans for 1981 and Beyond--Organizing Committee
0
Suggestions from Users, Computors, Experimentalists on Work of 1981 Conference and Data for Library (written comments priority). submitted before session will have first
PP1
D.
Peschcke-Koed t
KXix
GENERAL NOMENCLAURE Symbol
ConvenComputer
tional
BETA
0
DEL
6995
DELS
S*
Meaning
(dp/dx)
S.1.
6*/Tw
Boundary-layer
thickness
to 0.995 Ue
Displacement thickness
-
6 6
Energy thickness
-
d
m
U2 pU
6 pUee
Clauser thickness
1.
dy
Pl 2
P" [ PeUe
*
0
CLTH
m
ee
0
ENTH
e
dy
m m
Dissipation function
EPSILON
Units
2
sec
6 THETA
a
Momentum thickness
L e e
0
U
d
m
e
XNU
v
Kinematic viscosity
D2 sec-I
RO
p
Density
kg m3
Shear stress
N m-2
TAU
PHIL
OL
Left-hand side of momentum integral equation balance
PHIR
ýR
Right-hand side of momentum integral equation
balance CD
CD
Drag coefficient
CL
CL
Lift coefficient
CF
Cf
Skin-friction coefficient
CFE
Cf
Cf as reported by originator
CFLT
Cf
Cf according
CFPT
Cf
Measured using Preston tube
C
Pressure coefficient
CP
*
to Ludwieg-Tillmann
formula
p
*".•G
•','
Tw/ 2PeU e. T
6 P U ee 0*PU*
G
Equilibrium shape factor =
""
H
Shape factor **
HS
H*
o
KAY
K
Turbulence kinetic energy (u 2
pU 2 d(y/6)
/0
/0 + V
2
+ w )
-
xx
. .• •. . • . .. • ..
S.`
.. ` .
. .
. .
.``
..
-
" "' ' - .- -- -'
."-
."
I :
Symbol Computer
Conventional
LREF
Lref
)XM
H
XMREF
Mret
P
p
Pressure
PR
Pr
Prandtl number
PREF
Pref
PIUI
p--
QREF
qref
RE
Re
MLaning Reference
S.I.
length
UAts
M
Mach number Reference Mach number N m-2
Reference
-2
pressure
Pressure-velocity Reference
N m covariance N m-2
dynamic pressure
Reynolds number based on reference
values
Re= Uref Lref Vref
-
RDELS
R6 *
Reynolds number - Ue
ROIUl
_PT
Density-velocity covariance
RTRETA
Ru
Reynolds number
ST
St
Stanton number
STR
Str
TENTH
t+
*/v I
Ue
./V
Strouhal number
%
/CT2 Thermal energy thickness
T
St
-T wT T
w 6
XS *X
m
Coordinate normal tc an arc
m
V
V
Mean transverse velocity
W
W
Mean spanwise
UDEF
m sec-
e
UI
Uý
UREF
Velocity external
1
m sec- I m sec-l
velocity
Defect velocity = (UC
bU
m
e
Coordinate tangent to an arc
ean streamwise velocity
SUU
U)/U,
m sec
to boundary layer
m Rec-
-
1
Free-stream velocity
m sec
Uref
Reference velocity
m sec-I
US
U,
Wall shear velocity
UPLUS
U+
U/IJ*
UJ2
U2
Reynolds stress
m2 sec-2
V2
•
Reynolds stress
m2 sec-
W2
w
Reynolds stress
m2
sec
Reynolds shear stress
m2
sec-2
UlVI
272
uv
-
V7,7 w w
xxi
-..
.
.. .
. .
.
.
.
-J
.
m sec-I
2
-2
Symbol Converntional
Computer
Meaning
5.1. Units 2 -2 w 2em
UIWI
uw
-Reynolds shear stress
VIWI
vw
Reynolds shear stress
UnVm
unvm
Higher-order velocity
X
x
Stroamwise coordinate
m
2
covariance
Y
y
Transverse coordinate
PI
Z
z
Spanwlse coordinate
W
X
x or a
Streamwise coordinate on curved surEace
m
Y
y or n
Direction normal to curved surfdce
m
Z
z
Spanwise coordinate
m
yU*/v
y
YPLUS
sec-2
.-
Subscript
I
denotes wall value.
"w"
U20 2
I
e 2)
*
1 x
xU
U
6*
(UeUj'C
o
2
e 2-(U)
d-
-
2
eUo
x0
external to boundary layer.
denotes conditions
Subscript "e"
0
xxii
ii "' i i-.
'.. •
il i i .
i
"
•
. i
'
-
,
" -. .
."
-
. . .-
.- .*
", " .
-
-"
..'
.
.
-
- -i
PICThRlAL ý)UMMARY
The initial version of the pictorial and tabular presentation of
the
all
"Flows"
Professor S. Honami.
used
In the
appear
included.
"Flows
.*
as
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relevant "Case
pre~pared
by
All the major features of the flows
"Speciftcations" are
was
Conference
MI1einitial v.ersion has been modified and
edited for these Proceedings. which
1981
given
individual
here
the
for in the
chal L is
1981
numerical
repeated
Confferencc
are
order of
the
within
rhe
later
.*
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Kli
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TI VI
INTRODUCTION
S.
J.
Kline
GOALS OF THE CONFERENCE
I.
The Conference has three related goals: 1.
To
consensus
reach
in
data
on trustworthy
for modeling of turbulence
for standard
and as the basis tions.-
community
the research
that can be used as input
in complex
for checking output of
"trials"
sets
flows
computa-
2.
This library will The creation of a "data library" on magnetic tape. The hold the data selected as trustworthy in standard normalized form. data will be computer-readable and widely accessible at a moderate fee.
3.
Comparison of the lent flows for it
output
flows. The first
that
is
the
intended
of
current methods
result
of
the
effort
of
to
for
continue
at
for
computation
turbu-
covering a broad range of
least
some
years.
The
,
during 1979-80
nearly 200 workers
The second objective is
the 1980 meeting of the Conference.
in
culminating project
is
objective
of
set of "basic test cases"
an ongoing
third
objective
will be the focus of the 1981 meeting of the Conference.
term seems year
It
to be available.
research
effort
by
somewhat misleading for
is
The word "conference"
a
in
state-of-the-art
more accurate
to think of the project as a several-
fraction
considerable
establishing a more solid data the
is
of
the
Such
community
research
the situation
base and clarifying both
computation.
albeit no better
this project,
should
a clarification
be of
both users of computatational methods and to the research community in
It
is
my privilege to coordinate these efforts as Chairman
has been
ing ComL.ittee. to
share
The experience some
of
that
dealing with
the Conference
begin with a
brief
culties
in
The
and the
history.
turbuLence
sponsorship
research
of
the
This
with
the
readers
Data Library.
It
assistance
to
perceiving more
of the
Organiz-
will
and
subsequent
perhaps
volumes
be most useful
to
followed by a discussion of some current diffi-
is
S.
this
of
The third and
and fluids engineering.
U.
data and
The purpose of this introduction
has been educational.
education
at
roads to further advances.
and profitable
clearly what can now be done,
in the
aimed
Air Force
of
Office
Scientific
final Lopic is
Research
a
under
Contract F49620-80-C-0027 and the Industrial Affiliates of the Stanford Thermosciences Suggestions by Gino Sovran, Brian Launder, Peter Division is gratefully acknowledged. Bradshaw, Jim Johnston, Brian Cantwell, Geoffrey Lilley, and John Eaton on an earlier draft led to significant improvements and are also gratefully acknowledged.
1
..
v.° ° . - -.' ° •"
.- .- -° - - .
. - ° •- ". • -*".'
-.
--
-.
.-; - ; '.
.
' • .,
-" . "- -. ; - " . -. " -" - i
- •
, - - - •"" '
description of the Conference and how it
plans to ameliorate some of the difficulties
described.
I1. A BRIEF HISTORY From the early years of this century until the late 1960a the problem of computing the averaged
flow properties
unsolved problem.
of
turbulent shear
layers was considered a classic
With the advent of wide accessiblity
to digital computers a number
of individuals began to construct codes for solution of shear-layer problems. late 1960a, were
25 methods had been generated,
trustworthy.
construct
but there was no consensus thet any of themt
This lack of consensus was evidenced
new methods,
and by
the
By the
by the continued
funding of such efforts by governments
efforts in
to
-
several
countries. In
order
to clarify
Coles, M. V. Morkovin,
this situation,
W. C, Reynolds,
of holding a meeting at which as
a number of
many methods as possible
carefully standardized and trustworthy data. task of standardizing the data. Cockrell
and many
others,
research groups.
individuals,
G. Sovran and the writer,
D. E.
Coles,
includi.ig
organized
would be
tested against
with E. Hirst,
are described by Kline et a].
the
meeting
and
coordinated
efforts
in the two-volume Proceedings
and involved
some unique
among the of the 1968
that
from the perspective of this
Before the 1968 Conference,
that no satisfactory method existed. in
the general belief was
The excellent report of the Evaluatior Commit-
the 1968 Conference showed that seven methods were quite 3atisfactor.,
well-defined
limits,
and that nine mo-e had useful properties
Another nine were deemed inadequate, direct
features
is that the result radically altered the common wisdom concerning the ability
to compute turbulent shear layers.
tee
organizaLional
The con-
(1969).
The most significant result of the 1968 conference, volume,
.
a3sumed the
AFOSR-IFP-Stanford Conference on Computation of Turbulent Boundary Layers. structured
E.
The remainder of the group with assistance from D. J.
The results az.! recorded
ference was highly
D.
conceived of the idea
result
attached,
of
the 196.8
incompressible,
for some applications.
and have been for the most part abandoned.
Conferenze, turLulent
within
the
bulk of work
boundary layers ceased,
on developing
As a
prc[rams
and the researca
for
commu.i-
ity moved on to more complex problems.
*'
VI Available for purchase from the Thermosciencet Divisio'n of tht Department of Mechanical Engineering, Stanford University, CA 94305, USA. Price for both volumes, including mailing, $17.50. 'Chaired by H. W. Emmons; see 1968 Proceedings for detail. 2
S_.
I'-
Within
ences
a
years
following
1968,
r-asonable
free-shear
layers,
zone of wakes, The
"wrent.
had also
shown
that
methods
"trials"
the
emuloyed
bhown
in
in
"law"
modeling
The
compuLatinijl
resultIng
.
app're:iable
'
again find ourselves
zones
what
of
1968.
probleMr
they 1976,
1968 Conference
all
the
indicating
input in
far zones
for
the
near
will
in
again
began
result,
tnat of
or
Kim et al.
the type of correla-
successful methods in
the
1968
on data corre-
methods
and turbu-
many research centers arovnd
tle world.
at improving numerical
in
other
succeed
the prediction of a
turbulence-closure modeling.
flow fields, and
for
regions of detach-
in
follow
the "pustdiction" of
comalexities.
which
By
exist,
methods
the
late
3ut there
have
is
19703,
needed to
we
no consen-
advantages
for
we have been literally
a number of workers
to discuss what
thin sGhar
some cases involving unsteadiness,
the words of the old cliche,
As a
in
succesGful
a heavy dependence
have moved beyond
flow,
were
particularly
situatlon where miny methods
fused on a tigher level." the
methods
of entire
a
methods
Layer doeL. noý
Moreove:,
the wall,
separated in
Since about
experiments,
reattached
of
available
hag been carried out in
.layers to the compotation
flows.
confer-
These conferences
and simulation
required ad-hoc. "fixes"
a considerable effort
1970s
the
lence-closure
3n
similar
layers and the
1968 failed, qualitatively,
lation and hence a lack of fundamental
sus
layers.
boundary
of both data
that
Subsequent
such a
tion used by most
Durint
for free-shear
lack
failed or
but generally
free-shear-layer.
have
a
organized
1o"2)
for compressible
indicated
the methods presented
reattached (1979),
but
Conference
zones,
All
simulation
(1969,
jets and mixing layers.
1968
attached
r
NASA
for compressible boundary layers and
demonstrated of
few
what "con-
who had been ir.volved be done.
The 1980-81
in
Con-
ference grew from those discussione. Becauae plete
flow
tachment,
the lqBC-81 fields
strong wall-curvature far
larger
tions for -
of
than
tional.
such
in
concerns
complications
of
shear
layers,
and
other
phenomena,
1968.
the structure
sose current
Conference
with
reattachment
L
In
order
to
as
in
One other historical
shock/boundary-layer
large
zones
the
task
understand
of the Conference,
difficulties
"Complex Turbulent Flows,"
it
turbulent
remark is
of
at
these tasks,
will be useful
flow research,
in
once
de-
blowing/suction,
far more
complex and
and hence
the motiva-
to give
both
com-
interactions,
"eparation,
is
that iz,
a brief overview
technical and
order before discussion of
institu-
these difficul-
ties. Preparatory shown
that
an
examination.
work
for
important At
the
Particularly, writer.
the
element
beginning
M. V.
1980-81 of of
Conference
the
common
the work,
Lorkovin,
P.
during
wisdom
every
Bradshaw,
1979
and
does not
member of
1980
stand
up
-.-
*'.
'.
%
%'
.
.
H. W. Emmons,
.
.
already
to
detailed
the Organizing
W. C. Reynolds,
3
_.=...............
has
.
.
.
.
Committee
and the
was concerned with to
type
form a
The Committee
basis
for a
believed
that
than
50 cases
were
circulated
This
for
descriptions
continue
inputs
into the
.
cases"
for
signed
primarily so that
1981
cases and
15 such sets of data could be identi-
various
more
that many more exist but have
parts
of
the world
still
volunteered
continuing. Panc
data
iLts,
onto
who
magnetic
is
the
but has also overloaded
tape file.
J. Cantwell
tape
As a result,
it
is
the data
supervising
and
checking,
fitite
providing
the intention
library work,
library after 1981 until the backlog of existing data is this work
In
stantially
flow
B.
"caught up".
*
the
in
for each magnetic
and Prof.
writer,
flows?"
turbulent
ac the work progressed and evaluation reoo:cts
still
the
on complex
and something like
workers
entering
type
data sets of the necded
As data evaluations have accumulated,
of data has obvious
for
1968
10 or
Moreover,
that process is
available
che needed the
review,
disclosure
manpower
.
the
as many as
have been identified,
further data sets;
.
if
been fully evaluated.
not yet
of
of
conference
a meeting would be vell worthwhile.
fied,
of
"Are there enough trustworthy
the question,
meeting
(see
kifter
below).
the data compilation
secondarily
on
a
has gone
priority
to recording
September
sub-
"basic test:
the
priorities
were
as-
tape provided a balanced set
on magnetic
first-come,
1980
to
basis.
first-served
Further details
the section on Organization of the Conference below.
appear in
SOME DIFFICULTIES IN TURBULENT FLOW RESEARCH
III.
Technical Difficulties
A.
i. Te coplexity and variety offlw"•! Thin stricts
In
or condition
This
.
do,
affect
is
in
in
instances;
some
the
author
given
has
by a few
implicitly
World War
the
by a
list
list
Such a
of list
II, it
,
at
is a
no
guarantee
technical
the
meeting
one rethe
substance,
quite diverse and far from
As
as
a
single
state
data from hot wires
became clear
turbu'cnce
that
affected by many parameters.
that is the
Even when
Newtonian
simple models.
things
that
can,
and sometimes
collected over some
All the effects of Table there
however,
pure
turbulence was
turbulence. 1.
flows.
considered
demonstrated
Table
read
single,
of
is
largely after
the behavior of
is
a
but a complex of behaviors
well
author,
of
class
flow fields known to exist
(hopefully)
available,
complexity
flow
one-phase
research,
not a single state,
*
-
to
describable
became widely is
early
cohesive
form a relatively
of complex turbulent
cohesive. *
layers
consideration
totality
.
shear
time by the
I are known to be appreciable list
is
someone
complete. has
(Every
commented
time
on still
item--at least thus far.)
another
denotes a class of situations usually related In this volume a "flow" A "case" is one experimental realization of a flow, or a synthesis geometries. for computations. realizations, amalgamated into a single "trial"
4
.
...
°.
to of
The
complexity
of
'urbulent
problems or classes of tho, 1980-81 zation of entirely
This list
problems
complete.
fields
is
also exhibited
flows that have been considered by
Conierence.
flow
flow
foe
They
is
the have
been
These
reorganized
the
variety
of
the Organizing Committee for
exhibited as Table 2,
Conference.
by
which
categories
several
shows
the categort-
are neither unique
times
and
updated
as
nor more
information appeared. Still
a
third
indication
of
the complexity
of
turbulent
flow
fieldr. iL% given
by
the variety of levels of modeling that are currently employed for simulationI of turbulent
flows
number of
Since
both
globally
~ent
computer
models.
One is
Most current modeling
Table 3. a
in
subcategories the mean
taxonomy
of moduling
of
is
at
the
turbulence
four combinations
level
by
Kline this
three in
et
al.
(1978)
is given in Level 3 contains
ta>.onomy.
of models from simple mean strain to "many-equation"
flow and
(uniformly),
taxonomy lcvel
3 models
not confined
is
he modeled
locally
(zone
by zone)
of global and local modeling exist.
given
to level
can
3;
by
Reyn(lds
appreclable
(1968).
current
models.
However,
An excel-
the
efforts exist
or
totality
at all
five
levels for some problems. A
fourth
Bradihaw
:axonomy
(1975).
lence clo',ure
it
is
in
Tab'e
we are
i:
kinds of
claim
too
2. nct
juch
too
1980,
discussed. of
Table
model case,
1
2,
nor
various
It
situation. 2.
and
the
in
to the
several type of
papers
by
strainb
Prof.
Table
needed
model
the
Bradshaw's 1 shows
information.
group,
that
models
some are via
have to be able
for the computer simulation
I provides a warning for
disservice
and
A
categorization
that we shall ultimately
Table do
give
to the
of
those who would
insightful
and continuing
research community as a whole.
lackad a viable method for relating the several taxonomies
kinds
of
strains
whac
have what is
level
and
of
computation
effects
needed
hoped that the 1981
accurately.
for engi'ineering
of
roblasm--accuracy
turbulence
is
will As
ultimately long as
work in
be
just
that
needed
remains
complex turbulent
meeting of the Conference will begin to clarify
discussion on this point appears in
The measu.rewent
some
of
effects
flows.
know
More
provided by
thereby
we
is
according
that will
-re have adequate
do
.Mcasurement to measure
that
suggested
not knowz what methods are best applied to a given flow configuration
we shall not
fields. •.
we still
We do
all
been
flows
examination
turbulent early
has
tdea for organizing model assumptions for turbu-
have bee.
include
eFfo.ts of the turbulence In
arranges
experiments
However,
to say
complex
flows
a very fruitful
and suggesting
strain type. does to model
turbulent
taxonomy
of such experJ.ments
included
all
of
This
flow undergoes;
number
-
the floa the
the final section.
control
inherently
imporLant quantities,
to
difficuit.
We
for example vorticity,
have
lacked
instruments
pressure fluctuations,
5
Lt1
i2.
" . .
.
."'''
'""""
" '"'
•
pressure-strain correlation, the Reynolds stress tensor. bodies and in
instruments,
the
Tutu and Chevray,
uncertainty
dissipation
of
have
adequate
and
paper
below
nearly
turbulent
1976).
Kline,
by
every
flow reversals,
and
some components
data
X/D
<
hot-wire are
R.
energy,
means a
J.
Moffat)
kind.
It
Reynoldu
has
Jones concerning comparisons pipe in turbuletit Flow 0130,
of
of
remained
salutary
in
at
for example:
et al., is
for
hot-wires
this
for
example:
high
connection
to
for
read
by B.
the
rate
correlations.
(which
relatively
of
bluff
J.
Even where we have
fluctuations
uncertainty
turbulence data in the and of J. H. Ferziger on
behind
evaluation
1978).
high,
5
t'.an has been gener-
stresses and higher-order
the Nth--order
result,
is
quantities
for calibration
As
(see
1975; Colpq
many
in
taken
far more uncertain
owing to very large fluctuations
Flow 0410;
lacked
temporary
Fixed
the edges of wakes and jets
ally recognized Cantwell,
local
is
(see
discussed
turbulence the
We
Young in
data
remarks of
of
J.
a of B.
1=i
inlet zone of smooth, round strained homogeneous fields,
Flow 0370. The scribing
neophyte
instrumentation for
worker,
instrument
its
time,
seems but
moreover,
techniques.
is
to be
that of R.
badly
in
undetwrite or even undertake Wt.oility
is
faced last
The
need
C.
of
with
Dean,
Jr.
updating.
this task,
a
attempt
lack at
(1952).
unified
literature
coverage
deof
flui&
Dean's work was excellent
Publishers
and no institution
for seeing that such needful technical
of
complete
have
been
unwilling
seems to assuwe
tasks are carried out.
to
the respon-
Many engineer-
ing schools have never had, or have abandoned, advanced courses in thermal and flow measurements that would pruvide the student with solid preparation for careful datataking and reduction.t The result is that all too often our data sets are generated by an
untrained
committed
research-internee
supervised
of
by
a single
overworked
and over-
faculty person.
The only known method for reliable sie
solely
experiments.
tainty analysis
is
*This problem
However, still
is
is
results
of
the data
not used by many workers.
coming under control
innovations by Westphal et al. yet few data. tThe writer
the
control of accuracy
aware of
(1980)
via uncertainty
evaluations
and Owen
The experienced worker,
welcome knowledge
and Johnston
(1980),
of such courses of
others,
at
analy-
sh3w that
via laser anemometry and recent
only two sequences
-- both at Stanford. Re would stated in public meetings.
is
but
in
uncera known
instrument
there are as
the graduate
and has
several
level
times so
*The writer iu a biased observer on this topic, having written a base parer in the field. However, any other approach leaves significant questions unanswered and fails to provide numerical criteria by which compacibons between data sets or between data and computations can be made quantitative. Similar remuvrks have been made independently by D. A. Huraphreys and B. van den Berg in the evaluation of data for three-dimensional turbulent boundary layers, Flow 0250.
6
-
situation,
.an
perhaps
For a
neophyte
would
seem critical
rate
or a
po' 'tion
designing an
to
production
paper
the
experimental
on
.o the
severa)
long-standing
future,
we
are
details
of
uncertainty
in
a
intending
to
produce
data
of
of
trustworthy
that
problems
This
for
without
uncertainty
analytis
computer.
data
experiment
fortunate
conceptual
reduction
formal
truitworthy
person
Looking
data
produce
postible
datA.
is
Js
a
by
major
provides
however,
a
R.
"trials"
of
Moffat.
contribution
means
recommended
it
a sepa-
J.
by
which
fo: any experiment
trivia!
future
prepared
paper
utrongly
analysis.
For this reason,
been
also
are made
paper
uncertainty
a really new type,
has
this
and
formal
to the
employing
to any individual
computation
or
input
to
turbulence modnling. B.
Institutional
No
in
one
papers has
the
grown
presentation
recent in
compression of
This
Lase available
experimental catiun
of
details
This
but
against
a
reason
why
is
a
the
of papers
length of
in
adequate
papers
told
that the number of
a compression
acceptable
lengths has direct
means
not
that data must As
a
This
effort
of
journals
to many
of both
journals.
impact on th,• data
usually prevents discussion of
most
often be
result,
cases suppresses
read
from
data evaluators
for
fur
might
need the
computors
to
resort
research
who to
want
tho originators
community
has
and
the Conference
the necessary
been
have
Such a
fi.es. to
test
models
of
data
is
needed
in
one
order
to bring the data base into usable form. Moreovcr, without such a system as the data library now being established, the personal knowledge and files of 'he individual researchers would have The through ers
now-common discussion
may
carry
accessible
out,
record.
us believes
is
not
they are subjected of workors
•The
been lost to accurate
ten-minute on
discussions,
Ziman (1968)
"science."
time
but
in
they
told us at
Information
over time.
ef',ctively
prevents
the relevant
word
"computor"
fully
carrying
technical meetings.
Individual work-
are
of
no
book
longer
length some
and hypotheses
part
the
time ago,
become
to full public discussion and become accepted
in
to a "computer,"
presentation
points of disagreement
such As
recapture,
publicly
what one of
"science"
only when
by the large majority
field.
denotes a person doing numerical
which denotes hardware
fluid dynamics,
as opposed
for doing numerical calculations.
7
L
-
-*i'.
,
.
.*
.A
full publi-
too-small graphs,
of data to complete
feasible
flow3.
collective
most
detail and in
to the originators
of
to be
that with growth has come
times and paper
omitted.
normally
variety
needs
of computations.
in
sometimes
and
and
presentation
difficulties
often had to refer flows,
meetings
requirement
data.
are
research community
years
for "trials"
The length
p--
turbulence
in
times
Difficulties
.
'<
A
Still another institutiovial difficulty has arisen from what one knight characterize as to
the "ten-thousand-card
review
in
t'.e
older
program."
sensp
devote a matter of hours,
of
"review"
or perhaps
test
compounds
tor the
output
sets of data. th2t
What
"reviewiag"
the
cf
with is
is
position
examine
whether agreement wit' to
penetrate
to the
little flows
the
flows
constituted
computor rarely
(or
in
the
of the
she)
time
This
combination
Coaference time
in
of
has tended
in
nearly
in
us assume a
paper
About
all
provided
is
nearly
the
that
cotparison
data
time
test
hc
it
is
was
known
to
every instance
the
1978.
to reinforce
The
This usual
with one or more
(or
sent she)
the
made in
to unravel a3
wto
to can
code
the
the few
a
,-'
do
in
and
see
turbulence
code. as
that
clear
dataMo
restricted mandatnry
16
the
aore-
three
Even for the
Moreover,
ulnce
altogether possible
see remarks of Owen and Johnson
the planning began in
provided.
is
abhut
of viability.
sets,
grossly insuf-
for this discussion
that
codes.
became
it
meeting,
can
impossible for t1,± reviewer
take
of
reviewer
cited.
already
inevitatle assumptions
"minimum"
aifficulties
principle when
It
the utility
to assess
let
starements
clearly
like a
but
give2n
This is
been comparison
reviewer?
cannot
1968
tr'*stworthy data will be employ'ed;
is
obtained.
veýrifying
something
has
data
general
the
necessity
typical
the code is
data base
foregone,
this
showed
in
studied
of
of
implirations
meaning
class
of
the data is
closure an96 numerics. He over. the 1968 experience sets has
Pets
fe-i
the to
sometimes
of
the
The
review.
a printout of
of
computation has
a
to a given
even if
difficulties
Even tnis is
comparison
"viewer.
with
foc publication.
days,
ticient to unravel a large program, problem
Such large programs have not been accessible
the
that un-
(1980).
Organizing
Committee
for
the
Experience gained since that
the significance
of these prob-
lems. Data that evaluations showed were wrong by half an order of magnitude have been used as input to models in some cases. Questions and requests for further information havy
had
be
to
referred
by data
evaluators
to
the
originators
of
the
data
in
many
ingtanccr where the publish,!d record was not sufficient. Many deficiencies in both planning and detailed execution of experiments have come to light that could ha-e been s'oided had the experience available in the research community on provision for accuracy and oil
the difficulties
of
laboratory control
of
fluid flow
been brought
to bear
in a timely manner. The Conference hopefully
was
to improve
designed
matters in
to
ameliorate
the future.
some
of
these
difficulties,
and
The steps taken are described
in
thus
the next
section.
"This engineers
difficulty responsible
such managers
is also revealed and emphasized by for utilizing computational codes.
have expressed offered to them by consulting
the questions of mý.naginkg In a numbeýr of instances,
to the writer perplexity concerning firms which create numerical codes.
8
how
to judge
codes
*
-
IV.
ORGANIZATION OF THE CONFERENCE Some,
but
not all,
significantly reduced
of
the
difficulties
recited
in
the previous
section could be
by tt.ree accomplishments:
1. Provision of a trustworthy aata base ba.tked by consensus of the research community on its reliability and on its possible difficulties. To be fully effective, this data base needs to be computer-readable and widely
accessible. 2.
Clarification of data needs f3r constructing and checking computer models including: types of new or improved data required; data standards; the methodology for quantitative comparison of data and computation accounting for residual uncertainty In the data. TG be fully effective, this knowledge nieeds to be implemented via thorough review processes.
3.
The public- comparison of the standard "trials" wit,, at least a large number of different kinds of computer simulatiors in order to test several questions: a.
Does an adequate 'closure" model exist that can be utilized in feisihle running times, or, on the contrary, will it be necessary for eLlgineering computation to utilize distinct *'finetuned" models that are "tailored" to specific problems or to classes of problems in order to obtain reliable results of engineering accuracy?
b.
What kinde of turbulence-clozure models and numerics are more/ less successful, and in what classes of flows?
c.
any, for successful computer simulaWhat are the limits, if tion of complex turbulent flows in one-phase Newtonian substances in 1981?
=-:
IniLially, it
night
the
Organizing
be possible
progressed, needed.
it
became
As r
result,
evolved.
for
the data
tion are
given
parts
the world
of
its
in
Procedures only one worker,
this
from the 1968 exper
establish the data base
clear
that
both
the concept
reviewed resulted
A few discussed in
library.
the
Data
improved
of a
data
in
a suitable
data
and data
library
by in
Stanford
Library
a
paper,
be sent
shoulc
University,
were instituted that
is,
to
to create
committee
significar'
evaluations were the 1980 meeting.
4
ence,
closed of
form.
new kinds
as a separate, in
thought
Europe
that
As work are still
ongoing function to hold che tapes
The addresses of these organizations and cost informa-
%.ill be considered.
acquisition,
'and Astronautics,
was
reasoning
Agreements have been made with two organizations
produced
cluding
o
Committee,
of
page
58.
However,
all
to Prof.
Stanford,
B.
three
revisions
received
to
five
and
inquiries about J.
Cantwell,
the
inclusion
on the data base. other
workers,
improvements.
too
arrangements the
Dept.
late
for
In
prior
Each and
in
.
.
.
.
on review
most
addition,
and
--.-. ,
Aeronautics
by
data evaluation
9 .
other
"'Tape," In-
of
of data
review,
•." .
in
CA 94305.
insure against con'ensus
Similar
as
instances each
were
final
instead
evaluation
report and
ceived at Stanford,
its
eummary,
plus
a
specification
for computations,"
was
re-
was sent to at least two other attendants of the 1980 meeting
it
for review and possible comment.
As in the 1968 Conference,
in advance to agree to assist with the work as n condition
the attendants %ere asked for attendance,
and almost
wxthout exceptiun that agreement has been honored to the extent requested by the Organizing Committee. we~re
employed;
Also, as In 1968, such
completion
focused and recorded
as
procefiures to drive discussion co full completion
need
the basis
not
impl"
for further
agreement,
disagreements
investigations.
were
also
These meeting proce-
dures were rncorded in an advice to Session Chairmen and ave bourd into this volume as an Appendix to this paper. In
additiot,
to
nizing
Committee
dinate
information
Ccmmittee was
the
pro-. dures
acted as
of
liaison
and assist
not
in
the preceding
person
for
.orwstion
.rious
cne member of
evaluation
standaras.
the Orga-
ir. order
[nitially,
to
coor-
the Organizing
for the data evaluacors,
since
Only general guidarce was given the
that of formulating a data base,
result of the efforts of the data evaluators. by the fact
flow
standards
flows Is so diverse,
The most critical task,
paragraph,
each
of
able to provide detailed
the character of the data evaluators.
a
is thus the
Their tauk was made even more difficult
that the shape of the work process was evolved as information accumulated,
and the evaluators were only later asked to formulate summaries specifications
(for
trial computations).
The
(for publication)
field owes a considerable
debt
and
to the
arduous and insightful work of these experts on the various flow classes. These
procedures
infallible.
When it
do
is
guarantee
infallibility;
science
as
a
pzocess
comes to establishing matters of truth, however,
discussion of science sion of science
not
is
much better than any other known method.
the best we have,
and iL is
is
not
the full public
The public discus-
at least art order of magnitude better
than the assessment by individual data takers with respect to their own output.
Even
a cursory review of the full data evaluations for this Conference and the comments on them shows
this
"data takers,; be
obtained
clearly.
For this reason and also to make them available
the full evaluation reports are being held in without
charge
by
writing
the
Mechanical
Engineering,
accepting
long articles
Johnston,
1980); another (Launder and Rodi)
Stanford, or
CA,
condensed
A different lesson also emerged formulated over time.
Initially,
Thermosciences
USA
94305.
for
journals;
to future
.
file at Stanford and can Division,
Department
of
-
Some will be published in serials one
already has been
(Eaton
and
has been accepted for publication.
from study of the data evalvations as they were
the common wisdom sugg3: ted that tests of computa-
tions should be concerned with detailed comparison with sii,g]e flow fields of high complexity, for example the data of Cantwell and Coles (Flow 0410). However, it became that
clear from discussions
at least
with computurs
and the
two other types of comparisons are
reaults
tmportant.
of The
the data evaluators first is
*
limits on ',I
10
.
..
. .
•
11"
.
.
.
.
..
...
.
.
.
..
.
-
physical
behavior,
for example:
the cessation
of
turbulence
production
when a flow
passes through a lower critical Reynolds number (Flow 0280); or the reduction to similarity solutions for asymptotic 0130,
0260).
Finally,
range
of parameters is
rangc
verifies
flows,
an important check,
turbulenoe models
Second,
Nth-order
sense
uncertainty
in
,he
from
First,
"tuning"
number of workers, As in 1968,
involved
in
the vie of composite data intures estimates of defineid
in
the
paper
in
this
volume
by R.
J.
These three kinds
to checks on mathematical consistency as emphasized by a
for example Coleman Donaldson and John Lumley. the Evaluation Committee for study of the comparison of the data with
the computations will be chaired by Prof. from the
testing over a
processes
and thus avoids the difficulties of "one-lab" experiments.
of checks are all in additioi
input
for two r(asons.
independently
setting up particular flows.
Moffat,
as in a mixing layer or tube flow (Flows 0110,
the use of composites of data on Zirst-order results over a wide
1980
reeting and
are the responsibility of Prof.
H. W. Emmons of Harvard University.
the Orgt.nizing
Committee,
the methods of assessment They are left so in order
Emmons and his committ'ee.
to provide asseesment independent
from the organizers,
After
iata takers, and computors,
and
because they cannot be properly realized until the results are themselves in hand. A problem that wae foreseen but not initially understood was the question of how to review codes.
In 1968 every completeness
Stanford to insure
program utilized was checked by graduate students at Given the size of cur: ent codes
and repeatability.
and the titre required to adapt them to specific "roblems, such a procedure 's not feasible. Moreover, the basic problem of how to "review" codes needed some form of answer. The Organizing Committee dealt with this problem by designing a questionnaire that we hope will assist in
thi; p, oblem.
ceedings for the 1981 meeting. ate this questionnaire. invented
to
properly
It
It
Js worth noting that it
was only after
describe
the
the questionnaire
ii was
hierarchical
that an apparently usable questionnaire that
The quec ionnaire will appear in
will assist
in
of
took six revisions to cre-
found that new language had to be
structure
was derived. reviews
the Pro-
often used in
The Organizing codes
by
journals
cumputations
Committee hopes and industrial
personnel. These steps will hopefully computational section
lie outside
particular, of
fluid
dynamics.
relieve some of the problems Hei:ever,
9everal
problems
chat current-y mentioned
in
exist in the
the scope of work on the Conference and remain unanswered.
prior In
the lack of adequate description of experimental uncertainty and the lack
experimental control
it
implies
remain
continuing
problems.
They are well evi-
denced by the data scatter in the evaluations. Another -roblem adequate treatise
that lies beyond the scope of the Conference
L? .
the need for an
on experimental methods that will assist the data-taker in avoiding
known pitfalls in mensuration.
•i~i'11
is
t- j
Still another remaining problem to
Le
record
output.
experiments
The nature of
as
the
the matter of oversight in vhat are inte1ded
is
basis
for
possible
data needed for this use is
needs for past uses of data.
future
"trials"
of
computer
significantly different from the
These new needs have been little
discussed and hence are
the subject of a separate paper in this volume. These new needs, the lack of an up-todate treatise and the paucity of formal courses in aerodynamic measurements, all speak to the need for increased oversight in planning experiments beyond faculty persons working alone
(or with untrained assistants) who are contractually
How this may be accomplished is not clear at this
duce results on a short time-table. time.
A start in
this direction has recently been made by two sets of monitors
government bureaus, Finally,
obligated to pro-
and these examples may serve as at least a partial model.
the 1980-81 Conference will differ from the 1968 Conferenc,- In an impor-
tant regard that needs
to be clearly stated.
state of the art was such that
in
1968 the timing was fortunate.
the 1968 Conference
outcome can be expected from the 1980-81 flows
classes of
will need flows;
to
be
added
to
Conference.
the
Data are
many.
Nor is
and rapidly
can be expected
broad,
trustworthy
assessments
The most
data base and a
of utility
snapshot
for industrial
better guide to profitable
avenues
that
of
"consumers"
test
cases
for
the
Tables I and 2 shows. of
basic test
unblemished
cases
record
It
1981
meeting,
is
the beginning
programs and
Finally,
are not yet universal,
that will aid us with a
irovidc
the currcnt data library,
of a
it
needs to be and hence the
as a comparison of
must follow that even a successful model for a la:ge number
will not cf
of
reasonable to expect
state of the ari
for further researches.
remembered that the class of flows covered in basic
the
or, additional
fluid dynamn.2s is a young
Computational
field.
needed
it
that computational methods will be finished. improving
No such
The data will not be complete.
library.
improved data are needed in
The
essentially finished one stage of
work and led to another by showing that the problem was essentially solved.
More
for
past
yet
be verified
failures
in
as "universal."
extrapolation
of
Moreover,
turbulence
an almost
models
to new
classes of flows should warn us against easy assumptions concerning generality.
M. Rubesin and J. Marvin of NASA-Ames and J. Mobility Command, Moffett Field, CA. 12
McCroskey
and L.
W. Carr of Air
TABLE I SOME EFFECTS THAT CAN INFLUENCE CHARACTERISTICS OF TURBULENCE
A.
Nature of Fluid
1. Viscosity (i.e., Reynolds numbnr)I. 2. 3.
Constitutive (e.g., polymers) Energy release (e.g., chemical reactions) 4.Surface tension (e.g., oil-slick calming) 5.Cryogenic effects
6.
B.
C.
D.
E.
Multiphase fluid (several subcases)
Nature of Outer Flow
7.
6pI;x,
8.
Free-otream fluctuations (noise, turbulence)
9.
High Mach number (hypersonic)
ap/az
T
Wall Effects 10.
Blowing/auction
11.
Roughness
12.
Compliant walls
13.
Moving wall
:
Body Forties 14.
Coriolis
15.
Centrifugal
16.
Density gradients
17.
EHD. MUD
18.
Wall curvature: convex, concave (could be placed in type E)
19.
Curvature in free-shear layers (could be placed in type E)
Strain end Interaction Effects 20.
Shear rate and type
21.
Dilatation;
22.
Turbulence-turbulence interactions
23.
Downstream effects of transitions
transverse stretch!.ng/comprcssioii
.
'A
TABLE 2 FLOW NUMBERS AND CASES* ("Flow" denotes a geometry or class of related geometries; ded realization of a given geometry.) Flow Number
"Case" denotes a recommen-
Lescription Group I --
Evaluator
.
Numerical Checks
Potential flow in 900 corner Howarth flow (solution by Briley) AxisymmetriL: jet flow (solution in Rosenhead)
5
Flow in square cavity with a moving lid Flow Category
Group Ila -0110 0130 0140 0150 0210
,
0230 0240 0250
"
0260 0280
"0290 "
*
.
0310 0330 0340 0350 0360 0370 0380 0390 0410 0420 0430 0440 0470 0510 0610
Incompressible
-
Corner flow (secondary flow of the second kind) Entry zone of round tube ..... ............ .. Diffuser flows (unseparated) .... .......... ... Two-dimenaional channel flow with periodic perturbations ........... ................. Effect of free-stream turbulence on boundary layers ....... ................ ... Boundary-layer flows with streamwise curvature Turbulent boundary lavers with suction or blowing .......... .................... ... Three-dimensional turbulent boundary layers. ............. .................... .. Turbulent wall jet. ............. .............. Relamina'izing flows ........ .............. .. Laminar-turbulent transition .... .......... .. Planar mixing layer ..... ..................... Free shear layez with streamwise curvatu.e . Flows with swirl ......... ................ .. Ship wakes ............ ................... .. Wakes of round bodies ..... .............. ... Homogeneous turbulent f..ows . . . .. .. . .. . Wakes of two-dimensional bodies ... ......... ... Axisymmetric boundary layer with strong streamwise and transverse curvature ........ .. Evaluation of bluff-body, near-wake flows . ... Backward-facing step flow ..... ............ .. Diffuser flow (separated) ... . ........... .. Two-dimensional stalled airfoil ... ........ .. Flow ovet the trailing edge of blades and airfoils ............ ................... .. Turbulent secondary flows of the first kiad Attached boundary layers - ('68 Conference) . . .
F.B. Gessner J.9. Jones . Simpson M. Acharya P. Bradshaw T.W. Simon/S.
Honami
L.C. Squire D.A. Humphreys/ B. van den Berg B.E. Launder/W. Rodi K.R. Sreenivaaan E. Reshotko S. Birch P. Bradshaw A.P. Morse V.C. Patel V.C. Patel J.H. Ferziger V.C. Patel V.C. Patel B. Cantwell J.K. Eaton/J.P. R. Simpson A.J. Wadcock
ov Johnston
P. Drescher R.B. Dean D.E. Cles (Table 2 cont.)
As a result of the 1980 Meeting a number of changes were made in the Test Cases. The original form is preserved here as part of -he Proceedings. Please see comments on each case and the Proceedings of the 1981 Meeting for the final list of Test Cases used in the 1981 Meeting. 14
• ', ."•': •.'•' ".' ,- _ .
,
,
• i
i
"-
.-
,
" •
.
.,. -
.•i- " i
•--
. •.
. F
-
Table 2 cont. Flow Number
Description Group Ilb
8100 8200 8300 8310 8400 8410 8500 8600 8610 8620 8630 8640 8650 8660 8670 8680 8690 9000
Flow Category
-Compressible
Supersonic flow over a flat plate (insulated 'r.W. Rubeuin/ wall). .......................................... C.C. Horstman Supersonic flow over a flat plate (cooled wall) .MWRICCH Turbulent boundary layers with auction or blowing at supersonic speeds. .................. L.C. Squire Variation in Cf/Cf for blowing/suiction with Mach Number .. .................................. L.C. Squire Boundary layers in an adver~e pressure gradient in an axisymmetric internal flow .. ................ MWR/CCH Boundary layers in an adverse pressure gradient in 2-dimensional flow. ............................ MWR!CCh Compressibility effects on free shear layc;.s . P. Bradshaw Impinged normal shock wave-boundary layer interaction at transonic sptads .. .............. MWRICCH Transonic flow over a bump . ....................... R/CCH Transonic airfoilr ................................ R.F. Melnik Compressible flow over deflected surfaces . . . .MIJR/CCH Compressible flow over compression corner with reattaching planar shear layer . .................... M1/CCH Axisymmetric shock impingement (supersonic) . . .MWR/CCH Three-dimensional shock impingement (superso~nic). MWR/CCH Pointed axisymmetric bodies at angle of attack (supersonic) .................................... D. Peake (D.J. Cockrell) Axisymmetric n&uar wake (supersonic) .. ............ A. Favre Nonlifting, transonic airfoil with shock separation . ...................................... R/CCH Flows with buoyancy forces. ...................... J.C. Wyngard Group III
1. 2. 3. 4. S. 6. 7. 8. 9. 10.
--
Evaluator
--
Some Flows WaraningFurtherStudy
Full details of several blunt bodies including wakes: (buildldtgs, bumps, Radial wall jet flows Wall Jets impinging at angles to surface Unsteady mean flows (report pre.3erted by L. Carr) "Momentum-less" wakes Jets in cross and counter flow Twjo-dimensional separated flows (airfoil flaps) "Low" Reynolds number boundary layers Rough wall cases Airfoil cases other than~ transonic
..
Comments on Group III Flows Data on several flows in this group were called to the attention oi the Organizing Committee too late to provide evaluation or a suitable 'Evaluator" was not found for most of these flows. Hence they remain for future possible "eveluation" and inclusion in the data library. (Tabl-%- 2 cont.)
15
71 Table 2 cont. TEST CASE NUMBERS
Conference
Library
Reference Nt.mber
Case Number
Data Evaluator
Description Group A
Entry Cases:
-
Predictive
P1
0113
Asymmetric flow in square duct
P2 Central Case with Case E2
0422
Backward-facing step: opposite-wall angle
P3
0423
Backward-facing passage
P4
0424
Backward-facing step: area ratio
Org.
Comm.
Description by J.Eaton
variable .
Group B.I Sl
Data Taker
0612
step:
turned flow
variable
Simple Cases:
-
Description by S.Kline
Incompressible
On the turbulent friction layer for rising pressure
D.Coles
K.Wieghardt A.Samuel/ P.Joubert
S2
0141
Increasingly adverse pressure gradient flow
R.Simpson
S8
0371
Isotropic turbulence
J.Ferziger G.Comte-Bellot/ S.Corrsin
$9
0372A, B,C
Rotating turbulence
R.Wigeland/ H.Nagib
Sl0
0373A, B,C,D 0373E
Return to isotropy
M.Uberoi
Sl1
S12
H.Tucker/ A.Reynolds
0374A 0374B
Plane strain
0375A,
Axisymmetric strain
J.Tan-atichat
Sheared turbulence
F.Champagne et al. V.Harris et al.
A.Townsend H.Tucker/ A.Reynolds
B,C,D,E S13
0376A,B
(Table 2 cont.)
N
16 .
6.
4.,
.
.............
.--
Table 2 cont. Conference
Library
Reference Number
Case Number
S3
8101
S4
S5
Data Evaluator
Data Taker
Correlation: Cf/CfQ versus M-insulated plate
M.Rubesin/ C.Horstman
Various
8201
Correlation: constant M
M.Rubesin/ C.Horstman
Various
8403
Pressure gradient and Reynolds number effects on compressible turbulent boundary layers in supersonic flow
M.Rubesin/ C.Horstman (G.Lilley)
M.Kussoy/ C.Horstman/ M.Acharya
8411
Boundary layboundarler/expanvose pressure gradient
M.Rubesin/ C.Horstman G. L i ll e y )
F.Zwarts
8501
Compressibility r7 layerseffeca
P.Bradshaw
Various
8632
Turbulent boundary-layer/expansion interaction at supersonic speed
M.Rubeain/ C.Horstman
J.Dussauge/ J.Gaviglio
I.Castro P.Bradshaw
Description Group B.II
S$6 L -.
'(
•"free-shear ,.:S14 ''
'-',Group
C-
-
Simple
Cases:
Compressible
Cf/Cfo versus Tw'Taw
s on
.Entry Cases:
Incompressible
El Central Case
0331
The turbulence structure of a highly curved mixing layer
P.Bradshaw
E2 Central Cas,.
0421
Flow over a backward-facing step
J.Eaton/ J.Kim/S.Kline/ J.Johnston J.Johnston
E3
0142
Six-degree conical diffuser low-core turbulence
flow,
R.Simpson
R.Pozzorini
E4
0143
Six-degree conical diffuser high-core turbulence
flow
R.Simpson
R.Pozzorini
E5
0211
Effect of free-stream turbulence
P.Bradshaw
P.Hancock/ P.Bradshaw
E6
0231
Turb. boundary laycrs on surfaces of mild longitudinal curvature (convex)
T.Simon/ S.-lonami
P.Hoffman/ P.Bradsbaw
E7
0232
Turb. boundary layers on surfaces of mild longitudinal curvature (concave)
T.Simon/ S.Honami
P.Hoffman/ P.Bradshaw
E8
0233
Turb. boundary layer on a convex, curved surface
T.Simon/ S.Honami
J.Gillis/ J.Johnaton
E9
0241
Zero pressure gradient, injection
L.Squire
P.Andersen/ W.Kays/R.Moffat
with Case P2
constant,
(Table 2 cont.)
17
Table 2 cont. Conference Reference Number
Library Case Number
E10
0242
Adverse pressure gradient with
L.Squire
Ell
0244
Zero pressure gradient with constant (high) suction
L.Squire
A.Favre et al.
E12
0411
A flying hot-wire study of the turbulent near-wake of a circular cylinder at a Reynolds number of 140,000
B.Cantwell
B.Cantwell/ D.Coles
El3
0441
Flying hot-wire study of 2-dimensional turbulent separation of an NACA 4412 airfoil at maximum lift
A.Wadcock
A.Wadcock/ D.Colee
E14
0511
Turbulent flow in an idealized wing-body junction
R.B.Dean
l.Shabaka
Turbulent flow in a curved duct of square cross-section
R.B.Dean
J.Humphrey
El5
0512
Descciption constant suction
Data
Data
Evaluator
Taker P-Andersen/
W.Kays/R.Moffat
E22A
0111
Developing flow in a square duct
F.Geasner
J.Po/E.Lund F.Gessner
E22B
0112
Secondary currents in the turbulent flow through a straight conduit
F.Gessner
J.Hinze
E23
0261
Turbulent wall jet data (equilibrium wall jet)
B.Launder/W.Rodi
Various
E24
0263
Turbulent wall jet data (self-preserving on log-npiral)
B.Launder/ W.Rodi
D.Guitton/ B.Newman
E25
0264
Turbulent wall Jet data (3-dimensional on plane surface)
B.Launder/W.Rodi
Various
E26A
0281
Relaminarizing boundary layer
K.Sreenivaskn
R.Simpson/ D.Wallace
E263
0282
Relaminarizing tube flow
E27
0311
Planar mixing layer developing from turbulent wall boundary layers
E28
0361
"E29
0381
K.Sreenivasan
J.Laufer/
S.Birch
Various
The turbulent wake of a body of revolution
V.C.Patel
R.Chevray
Measurements of interacting turbulent "shear layers in the near wake of an airfoil (symmetric)
V.C.Patel
J.Andreopoulos
(Table 2 cont.)
18
18
....
...-.
- . -.. . .. .. .
.
.
.
..
Tbe2 cont. Conference
Library
Reference Number
Case Number
E30
0382
Measurements of int~racti.. turbulent shear layers in the near wr.ke of an airfoil (asymmuetric)
E31
0471
Trailing edge flows at high Reynolds number
P.Drescher
P.Viswan.3th eL al.
940
0431.
Separating adverse pressuLre gradieit. flow
It.Si-rpson
R.Simpson cot21.
R.Meinik
I'.Cook et al.
M.Rubesin/ 0.Horstnman
G.Settles et al.
L.Squire
C.Thomas
DatR Evaluator
Desczriptilo.
Group D
-
Enr
Gses:
..
ae
Data TakerL .Adepuo
Compressible
E16 Central Case
8621
Aerofoil RAF, 2822---presnure distribution, boundary layer and wake measurements
E17 Central Case
8631
Attached and separated compression corner flow fields in high Reynolds number supersonic flo~w
E18
8301
Favorable pressure gradietit at supersonic speeds with i~ijection
8(61
Three-dimensional swept !.hock/ turbulent boundary layer interaction
M.Rubesin/ C.Ilorstman
D.Peake
E20
8691
Non-lifting transonic airfoil, shiock-separated Ilow
t4.Rubesin/ C.Horstman
J.McDevitt et al.
E32
8601
Normal shock w.'ve/turb. boundarylayer interaction at transonic speeds
M.Rubesin/ C.Horstman
G.Mateer et al.
E33
8611
Transonic turbulent bo~undary layer separation on an axisyinmetric bump
4.Rubes in/ C.Horstjaan
W.Bachalol U.Johnson
E34
8612
Transonic bump, M
M.Rubesin/ C.Horstman
J.Delery P.Le Diuzet
E35
8623
Supercritical airfoil boundary layer measurements
RX1elnik
F.Spaid/ L.Stivers
E36
8651
Hypersonic shock wave turbulent bouindary-layer inzeraction--with and without separation
M.Rubesin/ C.Horstman
M.Kuasoy/ C.Horstman
E37
8663
Investigation of three-dimensional shock separated turb. boundary layer
M.Rubesin/ C.Horptman
M.Kussoy et al.
E38
8671
Pointed axisymmetric bodies at angle of attack (supersonic)
D.Peake
W.Ra inb ir d
E39
8641
Reattaching planar free-shear layer (supersonic)
M.Rubesin/ C.Horstman
G.Settles et al.
*E19
flow over two-dimensional 1.37
19
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di
I REFERENCES Bradshaw,
P.,
(1975).
Coles,
E.,
and E.
D.
"Complex Turbulent A.
Hirst,
(1969).
Flows,
JFE,
97,
p.
146.
"Proceedings Computation of Turbulent Boundary
Layers--1968 AFOSR-IFP-StaLlford Conference," Vol. 11. Coles, D. E., B. J. Cantwell, and A. J. Wadcock, Related Instrumentation," NASA-CR 3066.
Coampiled Data.
A1978).
"The
Flying
Hot Wire and
*
Dean,
*
Eaton, J. K., and J. P. Johnston, (1980). "A Review of Research on Subsonic Turbulent Flow Reattachment," AIAA (Preprint) 80-1438. Kim,
R.
C.,
Jr.,
(ed.),
1952.
Aerodynamics Heasurement,
MIT Press,
(out
of print).
J., S. J. Kline, and J. P. Johnston, (1979). "Investigation of a Reattaching Turbulent Shear Layer: Flow over a B&ckward-Faclng Step," ASME Symposium on Flow in Primary Non-Rotating Passages in Turbomachines.
Kline, S. J., M. V. Morkovin, C. Sovran, and D. J. Cockrell, (1969). Computation of Turbulent Boundary Layers--1968 AFOSR-IFP-Stanford Vol. I., Methods, Predictions, Evaluations and Flow Structure. Kline,
S.
J.,
M. V.
"Proceedings Conference,"
Morkovin, and H. K. Moffat, (1969). "Report on the 1968 AFOSRon Computat'.on of Turbulent Boundary Layers," JFM 36, pp.
"IFF-Stanford Conference
481-484. Kline, S. J., J. H. Ferziger, of Turbulent Shear Flows:
"NASA,
(1969).
"Compressible Turbulent Boundary Layers,"
NASA, 31972). 321. Owen,
Vol. Tutu,
-'"
Free
Turbulent
F. K., and D. Source of Error,
"Reynolds, "1968
and J. P. Johnston, (1978). Status and Ten-Year Catlook,"
Shear
Flows,
Vol.
5.
Opinion: JFE 1 0_0
"The Calculation 1, pp. 3-5.
n,
NASA-SP-216.
Conference
Proceedings,
A. Johnson, (198C). "Separated Skin Friction an Assessment and Elimination," AIAA-80-1409.
NASA SP-
Measurement
--
W. C., (1968). "A Morphology of Predictio-i Methods," Proceedings of the AFOSR-IFP-Stanford Conference on Computation of Turbulent Boundary Layers, I, pp. 1-15.
N., and R. lence," JFM,
Chevray, (1975). 71, pp. 785-800.
"Cross-Wire
Anemometry
in
High Intensity
Turbu-
P.
Westphal, R. V., J. K. Eaton, and J. P. Johnston, (19,40). "A New Probe for Measurement of Velocity and Wall Shear Stress in Unsteady, Reversing Flow," 1980 Winter Annual Meeting, ASME Symposium Proc., "Measurement aid Heat Transfer Processes in Recirculating Flows," HTD-13. Young, M. F., and S. J. Kline, (1976). "Calibration of Hut Wires and Hot Films for Velocity Fluctuations," Report TMC-3, Dept. of Mecbai.ical Engineering, Stanford University.
"Ziman,
J.,
(1968).
Public
Knowledge:
The
Social
Dimensions
of
Science,
Cambridge
University Press.
21
IL-
Appendix THE OPERATION OF SESSIONS--THE ROLE OF EVALUATORS, SESSION CHAIRMEN 1980 Meeting on Data TECHNICAL RECORDERS: , P-0AND Goals of Sessions: 1. Reach consensus on flows within the Basic Test Cases and many other flows as time and available evaluations allow. 2.
Complete di-cusaions by the end of the Meeting.
Each flow case will be presented asked to cover the following points: (i) (ii)
(iv)
by the Data Evaluator.
The Evaluator will be
Selection criteria Flows selected (zones
(iii) Specific computations flow L
as
Advices for checks, etc.
future
data
and output) Dpta
Lakers:
for each selected needs,
cautions,
A number of attendees, in addition to the review commlttee, will kI-ve ueen asked These comments when offered will take to study each evaluation and prepare comments. 1reay', beet, taken into (Review Committee comments will have prierity in discussions. account by the Data Evaluators.) Each session will be aboLt 90 minutes in All seasions will be recorded on tape. flows. Recorders" to assist the Chairman.
]ength and will typi.ally cover three Each sessior will have t-,o "Technical
In the evening following a given session, a committee on that session will Normally this convene to complete the discussion and clarify points under question. commictee w'll in'iude the Seasion Chairman, Evaluator, Review Committee Chairman, The task of this committee will be to produce Techr.i42. Recorders, and a few others. a succinct, clear record of the significant points of the session--in general, this will nct be a verbatim transcript. The -. es w1.1 not be t~a,-scribed; t-is is an enormous but seldom valuable task. Rather, the operators of the tape -,Achines will be instructed to create a footage log showing where various personb speAk in order to Frovide Access for checking remaeks where needed Given these resourceG, the Chairman's task will be to moderate the discussion and reduced to writing by the poiiitu are completed and accu:ately be suie that Recorders. 7t is nearly always important in this 2rocess to keep asking questions of the persons expressing positions until full clarity is reached, and then have the recorder rea4 b3zk the statement for concurrence by the worker concerned; the process As noted above in this packet, consennus as uqed should be iterated to closure. herein implies not only agreements, but also sharply focused disagreements wiLh the The iterative proceps name(s) of each individual holding a given position sLated. Juvt mentioned is particularly important in registering and focusing disagreements about specific idieas or mattcrs of fact. The Conference will provide sufficieht secreLarial assistance s, that the typed version of the output from the committee on each session canL be produced and posted by Inidviduals will be asked to approve (by the end of lunch on the following day. initialling) or alternatively comment in wriEl-ng to the Session Chairman by the evenit.g of thac day. 22
S:-
::::"::
:
! :::.i ) :
: : :-
: .-
.
-
FLUID
EXPERIMENTAL DATA NEEDS FOR COMPUTATIONAL DYNAMICS--A POSITION PAPER*
P.
Bradshaw,
B. J. Cantiell, J. H. Ferziger, and S. with Commen-s on Compressible Flows by M. RubeBin and C. Horstman
J.
Kline,
Joel Ferziger Peter Bradshaw 1.
INIRODUCTION This
position
tion
of
the
This
interaction
paper
interaction is
is
intended to provide
between
central
experimental
to
the
both experimental and computational appears
to have
separately. number cated 2.
of
been
neglected
Fbr this attendees
to its
reason,
prior
For the experiments drawn
the
Conference
recent of
computational to
effective
At the same time,
past,
this
and
compared
of the
Conference,
dynamics.
progress
in
The interaction
to efforts
paper was distributed
1980 meeting
fluid
delinea-
in
each area
[or comment
and
time was
to a allo-
discussion during the meeting.
BACKGROUND--NEEDS pasL
IN GENZRAL
decade
a
brisk
and computation likely roles
the
on
and
fluid dynamics.
in
the
data
present
a draft
to
a starting point for cleaver
in
discussion,
has
fluid dynamics.
on
the ultimate
roles of
Certain general conclusions can now be
data
experimental
of
continued
re-
the
least
for at
computation
and
mainder of the century. There ments
seems
will
"third
to be little
exist.
force"
in
question
CA-mputation
has
fluid mf, ,,inics,
that
a role
becoie,
and
for
both computations and experi-
will
strongly eugmenting
doubtless
remain,
the older methods
a
powerful
of experiment
and analytical mathematics. in
On the other hand, even optimistic estimates of the growth in size and reduction cost/flopt of large digital computers make it unlikely that the complete governing
differential will
be solved
numbers bulent least
equations of viscous
in
in
flows at four
feasible
this century.
hardware;
(ii)
turbulent
flows;
Commucrts acknowledged.
machine
as
on
(i) as
input (iii)
an
.Floatin.-point
undamaged by any kind of averaging
times for complex turbulent
Sire engineering applications
high Reynolds
purposes:
flow,
for for
numbers,
experimental
an engineering "'modeling" of
checking
earlier
ari~hmetir
draft
tool
approximate
the output
by
C.
of
Sovran
operation.
"23
flows at high
the
still
methods
B.
bE needed
development for
computations:
and
Reynolds
isually involve complex
data will
for
procedure,
E.
and
Launder
(iv)
are
for at
testing
computing
and
tur-
to
of
complex increase
gratefully
--
understandinS
the remarks of the para-
To be correctly perceived,
of fluid motions.
graph need to be carefully qualified. There is
no longer doubt that some important
time-dependent
computations
cannot be obtained This is
as large-eddy
from experiments--at
simulations)
for turbulent flows that
least with the instruments available in 1980.
already evident in such examples as compuptitonn of: the pressure-strain cor-
relation;
new,
important details of instability in laminar-turbulent
the linear range; 1980,
(such
results can be obtained from fully
important
transition beyond
and the dynamics of turbulence production near qolid boundaries. results of such types are still
to cee many more of them in
relatively new;
In
one expecto
however,
the next decade.
(See also final paragraph of this sec-
these important advances,
one must at the same time be conscious
tion.) In recognizing
of the limitations of machine size and cost.
In particular,
costs
types
make
it
feasible
to
run
the
largest
of
the present and projected
programs
only when
scientific results can be obtained once and for all, or where economics, tions,
or performance
corporate
or goverr-ental
costs per (megs)flop will remain rare, and (ii)
demands,
make
the problem of overriding
institution.t
suggest
restricted
that:
of
(i) machines capable
to very large institutions
legal condi-
importance
to a large
larger machines and reduced of
this kind of computation
owing to
large first costs;
the costs per run will remain so large that the most powerful approaches are"
unlikely to become the methods of most
N.
Projections
important
day-to-day engine2ring computation within the
twentieth century.
"The lows.
remarks
to this point suggest
two foundations
First, a need for approximate (specifically,
for the discussion
time-averaged) methods of computa-
tion of turbulent flows at high Reynolds numbers will continue
S
that fol-
to exist.
It
follows
that we will continue to need a data base to build simulation models and to substantiate approximations.
however,
The nature of the required data base is,
strongly af-
fected by the specific needs of computation--both for forming models and for checking
Soutput
for central
*
various
question
of
classes this
of flows.
paper,
The requirements
and for
the conference
for
this
data base forms a
as a whole.
Second,
it
L
is
For example, large-eddy simulations or models employing transport equations foi" Reynolds stresses in closure approximations. tFor example, computation of flow in piston engines relatin.g to creation of pollutants, the design of critical elemento of turbomachinery affecting aircraft performance.
.. *
*D. R. %V
Chapman (1980,
and personal communication)
suggests
that design of
some
critical turbaaachinery elements by these methods may occur within the 1990s owing to: (i) low Reynolds numbers in some cases; (ii) relatively simple geometries; and (iii) high cost and difficulty ot adequate performance testing. 24
- --- - - - - - -
AI
already
evident
that computations can both supplement and aid in interacting experi-
mental results. computations
There is
accordingly
an inverse question:
that will aid design of experiments,
advise on the nature of useful experiments?"
"What
can be learned from
supplement experimental data and/or
Some applications of large-eddy simula-
tion to results not obtainable by experiment have
;lready been suggested.
The adap-
tive-wall wind-tunnel is an example of the use of computation to aid experiment; tunnels are particularly
important
for cransonic flows and for some classes of complex
flowis (for example separated flows)
at all Macb numbers. Two instructive,
impnrtant aid to understanding data. cations
such
have kindly been supplied by F.
Computation can often be an recent examples ot such appl 4 -
A. Dvorak of Analytical Methods
Incorporr
and are attached as Appendix 1. These examples of the importance of data to good numerical computation to improvements of experimente arficient,
however,
by P3 means exhaustive.
They are sut-
to illustrate forcibly the import;mce of using experiment Rnd corp--
taLion to augment each other iteratively, and improve engineeting design methods.
as the effective way to increase knowlcdge We make this remark specifically to emphasize
"that while
the focus in this paper is on data needs,
preference
for experiment
prosper bese
fluid dynamic3 and of
alone,
or for
computation.
the intention there is
On
there ip no intention to imply a the contrary,
since neither will
to help clarify means for effective inter-
action between experiment and computation. 3.
SPECIFIC NEEDS IN `XPERIMENTATiON In
order
to
specitic needs
consider
types of experimentG,
clearly,
it
i.
helpful
to
consider
a.
Data on quantities of direct importance for engineering design.
b.
Data that will be useful in either construction or checking models for practical simulation of complex turbulent flows at high Reynolds number.
c.
Information that improves understanding of underlying physics of fluid motions.
This
"needed
paper
is
primarily
for category
categories (a)
(b)
devoted
to
the
discussion
has some characteristics
complete enough to specify a test case.
category
(b).
that differ markedly
The
data
from those of
is the need for initial and/or boundary data In many computational methods,
velocity data but also Reynolds stresses (and
mind,
that
is,
to
choose
at
not only mean
perhaps triple-products and dissipation
rate) reed to be specified over the initial surface. in
of
or (c).
The first distinctive characteristic
with this
three
depending on the results desired.
least
Experimenters one
possible
need to take data
"initiating surface"
25 S....
..
..
.
..
.
..
.
:. ....... .- ........-.. _.
.
..
.
..
-. ,,....
•......
-.....
..--.
... :
,.....•
.:..-.:".
..
:
-..
''
"2..
% and document
the
flow
at
that
surface
with
as
much
thoroughness
as
is
feasible.
Presumably the 1981 portion of this conference will make the precise needs clearer by providin:, a "catalog" of
what
inputs are needed
for various successful
computation
methods. A word of caution concerning the measurements of flow both at the initial surface and elsewhere is needed. A well-documented experiment needs to record not ouly the mean flow and fluctuation quantities but also the presence or absence of such phenomena as:
ing)
(i)
vortex
steadiness; ically;
gross unsteadiness;
structures; (v)
(iv)
(ii)
the
vortex shedding;
presence
(or
(iii)
absence)
any other
"unexpected"
(or
of shock patterns
the existence of more than one flow pattern
and (vi)
stationary
flow behavior in
meander-
and their
periodically or aperiod-
the situation under study.
This implies the use of flow visualization and/or unaveraged and un-Fourier-analyzed, conditionally sampled rake data. Phenomena of this sort way not be part of the "turbulence field," but may nevertheless affect it to first order.* Moreover such information is essential to identify zones where particularly accurate time calculations or spatial
resolution are
necessary
in
the computations
evolution of the dynamics of the flow field. is
to distinguish gross
understanding,
if
one is
to obtain a correc'"
The information is also essential if
unsteadiness from turbulernce,
one
and thereby obtain appropriate
or to sort data from one flow mode from that of another (see Appendix 1
for example).
Geoffrey Lilley has made a similar point in a different way. earlier draft of this paper,
In commenting on an
Lilley noted that turbulence production can be written as
an integral of quantitis of the form q x w, where q
is
the fluctuating velocity and
w the fluctuating vortieity vector. It follows that one must document the components of velocity and their derivatives not only in the direction nnrmal to the surface choacn for initiating computations but also the velocity components and their derivatives lying in the initiatIng surface unlces the flow at the initiating surface
is
clearly
known to be wholly irrotational. The second characteristic profile well.
measurements Third-order
of
the
of experimetital dats for category mean
correlations
flow
and,
are useful
surements of dissipation are aseful,
if
possible,
but generally
(b)
is
turbulence have lower
the need foe quantities
priority.
as
Mea-
but seldom can be made accurate enough for use in
comp,'tations. The that
nature of
the question
"simple"
fluid measurements of experimental
geometries
of
the
most
and the subtleties
of fluid motions are
uncertainlty must have a prominent role. common
sort,
the
data
scatter
among
such
Even in various
Emphasis on this point and most of the language of this paragraph were kindly supplied by Dennis Bushnell of NASA-Langley Research Center. 26
"L _"j
generally larger than most workers wouii.
experiments is report
by
reason,
J.
B.
Jones
on
the
entry
region
of
a separate discussion on the analysis
paper by R. J.
a
expezt.
round
tuLe
of uncertainty
in
and to the
An example tion
for
this
on wall ances
this point atooe in
Conference.
jets,
R. L.
the
right-
in
formulation of acceptance/rejection
illustrating
In
Simpson and
but
than
experimental
total
quantities.
Since the
experiments
thoroughness, than
of
on the
it
information.
the
strongest
has
uncertainty
in
is
(b),
category redundant
it
is
by R.
J.
Moffat and,
accuracy of
each output
ter program.
Routine,
facilitating
result
difference in
this
Launder
and P.oddi
to attribute equation
between
to
difference
the
unbal-
"
"threeis
less
two
summed
is usually
large,
is
and more than
instrument, for category
for category (b),
,nc-irtainty
analysis is
is
of outcomes.
Tie primary
the time and trou'ile required.
done,
essentially
the
anslysis
in
argument However,
design of ex-
added work needed to estimate the
trivial
careful use of uncertainty experimental
of
instructive
control
is
one type
extreme
be more
the use of uncertainty
that
with
to do one experiment
that might
for
shows, once
comparias.ns between
recommended.
been conventional
better
measurements
tool available
critical,
-1
for data sets.
data evaluation of
the
In planning an experiment
single
the paper
periments
criteria
significance.
raised against use of uncertainty analysis as
the posit-Jon
to comparison of data to
of the momentum-integral
a variety of experiments
(c)
'
-""
the preliminary work of data evalua-
experimental uncertainty
including
to provide
given in
For
that this attribution has no validity when the unbalance
Simpson's point has considerable In
that
left-hand sides
dimensionalizy," the
commenting
noted
Lhe this
for example, 0130).
Peoper understanding of Luch analysis i,; impor-
Moffat in this volume.
tant to the comparison of data sets from different rust rigs, computation,
See, (Flow
when data are reduzzd by compuanalysis would go a long way toward
results and computation,
(See also remarks of B. Cantwell on requirements
and is
strongly
.
for future accessions
to the data library.) In detail
addition to deciding what measurementn are to be made (to be discussed below),
data,
and
the
range
which
the
experimente
accuracy
his
are
needed,
statements of
the
Cheap
In
the
measurements.
will
cover
experiments
be
forced
that
for
may
remember
choose
range
In
most
and which
and enough simply
imply
measurements experiments
that
are
may
be
st:-eamwise
range and
determined useful
by in
the some
points
density,
and Lo
experimenter's cases,
but
explore,
producing
for
derivatives
to permit
to
the widest
the
capable of
"enough
taken
time
of
involving advanced and expensive data analysis, only
is
he will use
spacing
the
should be
the
cases
the
results of
many purposes
profiles
variables,
the
to measure
there
of
more
and
number for which his test rig is
required accuracy.
should
the
experiments
highest Reynolds
experimenter
of
must
in
a smooth
curve."
of measured
this.)
:w4
(He
quantities
These semi-tvivial
some extent the accuracy, budget
experiments
of
time
which
and money. are
L
.•
poorly
27 -I
planned or that have to be skimped for lack of time and money are often useless, a4y even play a negative, than what
is
measured
calibration chains,
whether
the result-s
d.ita from a careful
Wherever
possible,
in
analysis
later
trustworthy.
or if
and procedurej,
all tend
the turbulence
from his hot wires, analyzed
are
Redundancy
closure checks using fundamental principles,
documentation of test configurations the
Far more important
time-consuming role in data evaluations.
is
should
if
more
complicated
tunnel documentation,
of this
trustworthiness.
record the fluctuating signals
poasible his laser velocimeler,
years
checks,
and fuily reported uncertainty of
toward creation
experimenter
and
so that the data can be re-
statistics
become
of
interest
or
if
queries arise about the data. A further ence with many
problem regarding
trustworthiness
is
that of "one-lab" data.
flows evaluated for this conference suggests
relying on a data set from one lab and one apparatus. tainties higher for
Experi-
the very real hazards of
Not only are residual uncer-
"one-lab" data, but also, far more often than not, comparison of
data frcm several test rigs raises fundamental questions that need resolution by further experimentation. Johnston, as:
(See
J. B. Jones,
(i)
laminar-turbulent
separated
flows,
for example
and S. Birch.)
data evaluations
of
J.
K. Eaton
and J.
P.
L
This remark has p<'icular force in cases such
transition;
(ii)
near-zone
of free-shear
layers;
.
and (iii)
and other flows which are sensitive to variation of the spectrum of
I
incoming disturbances. A special
situation arises
in
data
involving
very
high
levels
of
fluctuations
and/or rapid local flow reversals, as in zones of incipient detachment. of Cantwell (1980), Eaton and Johnston (1980), Owen and Johnson (1980',
The remarl._ and Simpson
(1980) should be consulted for any flow possibly involving these kinds of situations. As all these authors show nearly all older data are inadequate, and onl:" relatively recent laser data, the potential for producing mentation
available
in
time-of-flight probe data, or flying hot-wire data* have trustworthy data for such flows (in terms of instlJ-
1980.)
Consequently,
there
is
a need for more categoiy
(b)
data in these situations. In data.
general,
consistent 0130).
the
scatter
in
turbulence
data
ln some cases good mean flow data exist, band
of data
(see
for
Part of this difficulty
is
example
is
much higher
than
in
mean
flow
but the turbulence data do not form a
the
evaluation
of
J.
B.
probably owing to the failure
Jones
on
Flow
to calibrate
wires for fluctuations and/or for a suitable value of the yaw constant.
hot-
A procedure
The earliest clear recognition of this problem seems to have been by D. E. Coles and co-workers at Cal-Tech, circa 1972. Their solution of the flying hot-wire is adequate but quite difficult to implement compared to laser or time-of-flight probe measurements. 28 ""m,.1
.-. .
. . . . --
...
. .,- .
*.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
for
in
provided
is
calibration
such
Engineering
Mechanical
the
of
TMC-3
Report
Department of Stanford University (available on request). A case of special difficulty in documentation is flows involving instabilities, The reas in the early zone of free-shear layers and laminar-turbulent transition. Reshotko and M. V. Morkovin on laminar-turbulent transition records that no
port of E.
case is yet sufficiently well documented to make a reliabla basis for computation possible. Such cases form an area where discussions between computors and data takers will be of particular importance in establishing trustworthy data.
(A working commit-
tee in the 1980 meeting has made a more detailed report on the question.
See report
on Session XIII below.) the documentation of shock waves in cam-
Another area warranting special care is pressible
flows.
Observers need
to note not
frequency akid amplitude of shock motions, or
intermittently.
the
shocks
Careful measurement
including
turbulence
only the mean
position,
and whether shocks are present all the time of
the upstreem and downstream conditions
measurements
are
needed
for improving
checking output (see also summary of Rubesin/lorstman Flow 8650 Considerable fluctuations in
questions
the
concerning
from the
...
of
modeling and
).
for
reduction of the output of hot-wires
transonic and supersonic regions
working committee
but also the
also exist.
A speLial report of a
1980 meeting will expand on this topic.
(See
reports in
the Session XIII below.) Most of the remarks of this section can be summarized by noting that experiments
"are
useful
for
thoroughly,
category
where
of
this paper
the word -documented"
only when
is
used
they are documented
in both of two senses.
extremely
In the first
implies measurements of the flow field that provide a complete pic-
documented
sense,
(b)
ture of the real physics of the flow, each output point.
It
is
with a statement of the uncertainty involved on
important to realize that estimates of uncertainty at given
odus need themselves not be of high accuracy in order to provide a quantitative basis for comparison of experiments and computations. the uncertainty whether
it
reporting
on a given result is
is
of
and
c.nditions,
so
constructed.
18% or 20%,
the order of 20% or 2%.
sufficient
trustworthy
information
so
supplied
with
is that
a
suitable
For example,
that
test
but it
is
DocumnieLaLion the reader
oufficient case
for
is
{t is
irrelevant whether
c-itical in
the
'econd sense means
convinced
information, cot--)arison
with
to know reliably t.hat the data are
especially
initial
computation
can
In a number of cases used in the 1.980-81 ronference,
be
written documenta-
tion was not sufficient
for this purpose and data takers had to be consulted in order
to establish sufficient
information for the formation of trial cases.
Cases existant.
of truly steady
shock location
seem
to be extremely
rare,
perhaps
non-
29
-
. ..
.
.
.
.
-. ' . . -- . . . -- - - -
.
. . - .
.
.
. .
.. .
Z
....
..
.
. . ..
•.
., - . -
-. .
*
-. - .
. . .
.
.
. - ..
.;.
.i
._
. .
It
is
the lack of documentation
in
these two senses that
has made
the bulk of
past data less than adequate for use as trial cases for checking current computational methods
and for interacting
effectively with computations
in
the attempt to advance
knowledge and improve engineering methods. Collectively we have see if
we will utilize
the ability to do far better in
it.
(In
the future,
it
remains
to
this connection see also remarks in the Introduction
to this volume concerning oversight and planning of experiments.)
4.
BOUNDARY CONDITIONS (INCLUDING INITIAL CONDITIONS) An experimental
investigation of any fluid flow problem,
for coaparison with computed output, cation of the satisfied
flow field is
to meet
made,
the needs of
which can later be used
must ensure that a complete and accurate specifimeasured,
and recorded.
all computors,
even if
This requirement
this means some
must be
redundancy
in
data for certain computors. Formally, the boundary-condition information required depends not on the flow but on the equations to be solved. It is important that sufficient data be
given at
all
boundaries
to allow mass
and momentum balances
to be
constructed. It a.
In
is useful to consider thp following flows: "thin shear layer" flows,
i.e.,
having small d6/dx and negligible
equations are essencially parabolic,
Profiles of all variables except V are required at all inflow surfaces. The minimum requizement is for the velocity U (and W) and the shearing stress W (and .Vir,.
(ii)
The external velocity Ue(x,z) or pressure p(x,z) is implies the boundary condition as y tends to infinity.
(iii)
Boundary conditions at a solid s~trface, unless stated otherwise, are the usual no-slip conditions. If there is significant surface blowing, suction, or wall roughness, this should be speciffed as accurately as possible.
(iv)
The shape of the uolid surface must be accurately given.
(v)
The V-component far from a free shear layer is determined by conditions outside the shear layer and must therefore be specified.
In "slender
shear
the
conditions
initial
velocity
components
layers"
(e.g.,
should
the
and the needs are as follows:
(i)
V.
b.
;p/3y,
streawvice
include
all
corners, Reynolds
required
non-circular stresses.
and
ducts, All
etc.),
three
mean
ehauld be accurately measured so as to define the streamwise
vorticity. Boundary
conditions
for 3-D obstacles
in 2-D boundary layers will generally
be given upstream of the obstacle and will be as in (a)
30
above.
....
.
.- .
oj .
.
In 3-D cases,
.
the domain, Humphreys
.
such as swept wings,
surfaces" across which on the outboard
.
initial data are needed on on all "inflow
fluid enters the domain;
portion of
the wing,
for example,
den Berg
in
the
the flow
data are needed on the inboard boundary of
because boundary-layer fluid flows outboard.
and van
to compute
See also the remarks by
full data evaluation
on Flow 0250;
they are
particularly thorough on three-dimensional boundary layer documentation. c.
Two-dimensional elliptic flows can almost all be chosen to begin and end with thin shear iayers (e.g.,
flow over a backstep).
Computors will usually assume extrapo-
lation conditions at the downstream boundary (i.e., ties).
The experiments
3/ax - 0
]
for all mean quanti-
should provide data indicating whether this approximation
is accurate. Flows which are genuinely elliptic at the downstream boundary can cause difficulty (an example is a diffuser with a screen at exit). boundary conditions
in
the data are over-specified,
tion method will accept in
K.'"
only a "sufficient" tiet;
No harm Is done if
the
because a well-posed calcula-
this presumes
the uncertainties
the data are not so large that significantly different results arise from dif-
ferent choices for boundary conditions. Inviscid-flow pose no problem. like
cases
boundary Usually,
backstep flows,
uniform
airfoil
for
(e.g.,
conditions
calculations)
should
flow at infinity will be assumed. In some The geometry needs to be specified.
4
the upper-wall
boundary-layer displacement thickness on the upper wall may not be negligible and, if
5.
not,
should be given.
RESULTS TO BE USED IN CHECKING OUTPUT OF COMPUTATION The results need not include all computed quantities.
culation
methods
yield
values
for
the
For example,
turbulent-energy-dissipation
7
many cal-
rate;
however,
there are no direct measurements of this quantity of sufficient accuracy for checking calculations,
and hence one does not expect
a check.
mean-flow measurements are a minimum requirement, of the departure employed
in
volume.
of any "two-dimensional"
As already indicated,
and they should include an estimate
flow from that ideal state.
various cases for ensuring two-dimensionality
In
principle,
the
static
pressure
can
field, but in flows other than thin shear layern it sure measurements within the flow. rated flow3--that
Unfortunately,
detailed
be
is
deduced is
it
The criteria
exhibited later from
the
in this
mean velocity
desirable to have static presis
in such flows--notably sepa-
static-pressure probes are least accurate and most likely to disturb
the flow.
It
is
highly desirable
ents affect the mean flow.
to have measurementa of all Reynolds stresses whose gradiThis is especially true when the acceleration is dominated
31
...... ...............-
.
*
*.......
..
S~j
by
gradient,
pressure
inviscid equations;
in
Most fPows with significant Reynolds-stress gradients are shear is
which shear stress
-rJv
the Reynolds
of
stresses.
the latter quantity is
and -Pvw;
In usu-
in hot-wire measurements as the small difference
appearing
to measure,
important
the most
has components
three-dimensional flows it ally difficult
the
the mean-flow quantities are an insufficient test of
consequently,
the turbulence model. layers,
be made by
such regions can
in
mean-flow predictions
for
of two large quantities. Many transport
modern
The
equations.
sides
right-hand
of
ences
the differences
Triple-product
and are therefore
presentation of the carefully estimated uncertainty values.)
in need of
particularly
triple
found as differ-
(Quantities
to large experimental uncertainties,
liable
are particularly
mean
the major unmeasurable terms
the other terms.
of
contain
these equations
velocity correlations which are effectively unmeasurable; as
Reynolds-stress
they also contain viscous terms and pressure-
products as well as Reynolds stresses;
can be deduced
the exact
based on
use models
methods
calculation
for the deduction of dissipa-
may therefore be necessary
measurements
tion and the pressure-strain
'*redistribution'* term as the
"difference"
relevant transport equations,
as well as being of intrinsic
interest
terms
in
the
as the dominant
parts of the turbulent transport terms. Transport products,
are used high-order
contain
in
some
methods,
calculation
derivatives
of
but
the
fluctuations
velocity
transport
equations
unmeasurable
pressure-
exact and
techniques appear,
Unless new measurement
fluctuation terms.
such as dissipation and triple
for higher-order quantities,
equations
it
not realistic to
is
discuss data needs for this application. measurements,
Conditional-sampling
contrast,
in
are available
variety than can be used explicitly in Reynolds-averaged
in
much
calculation methods.
greater Little
progress has been made in developing calculation methods based on conditional sampling concepts.
The main value
of conditional-sampling
providing qualitative inspiration tween
large-eddy
simulation
appears to be beginning.
measurements
for turbulence models.
computations
and
more
thus far has been in
However,
detailed
an interchange be-
structural
information
See Section 6 regarding Large-Eddy Simulation data needs.
Unsteady flow measurements must be made by some form of conditional sampling; in periodic ages
are
are used,
flows phase-averages necessary.
There
is
room
for
while
ingenuity
techniques are usually helpful in such cases. available for unsteady flow.
in a periodic flow true ensemble averin
".....
Digital recording
A report on the state of data in unsteady flows by L. W.
"32
...
area.
Relatively few data of any sort are yet
Carr was presented to the 1980 meeting (see Session X1I).
-.............-...............-
this
K
6.
DATA NEEDS FOR LARGE-EDDY-SIMULATION MODELS Large-eddy
Free-shear ficult
simulation
(LZS)
is
layers and channels are
flows
will be attempted
these reasons,
limited
in
as time
at a higher
to
the most difficult
geometrically
flows
to relatively
level of detail
simple
yet attempted.
goes on and comp-ters
the data needs are restricted
the method operates
1980
increase
flows.
More
in
dif-
power.
simple flows;
For
but,
because
than do time-average methods,
LES re-
-I
quires more detailed data,.' Since large
it
large eddies data;
explicitly
LES
eddies,
would
in
a
these data
should that
include
computes
benefit
flow.
In
least
particular,
two
decades
this
information
be routinely
made some
experiments
impossible
components,
This
and
information
data
on
the
is in
the
one
spectral simple
without
ideally
realization
data on
the
that
of
the
nature of
the
requires
spectral
small scales (high wavenumbers),
for
to simulate
of
least
the one method
reliable
reported
should
at
from detailed
it
of
spectra
of
behavior
need not be very accurate
at
tial spectra.
the
considerably
information.
flows;
many
of
of
ausumptions
be available
the products
lack
We
but
recommend
such data has as
to
the
ini-
for each of the velocity
the components
would also be
useful. In quite
the
past,
useful
tions.
The
and
a
number
several
latter
large.
it
has been impossible
It
would
(with
it
documented
suggested
computor
different
can
obtain what
requirements,
it
There case
several
"Some
is of
clearly flows
instances,
examples
include:
reattachiag
"of
entry conditions
flows;
transition;
evaluators
a
velocity
because
the
the small-scale
experimenters
before
computing
is
by
r
limited,
products.
low-pass-filtered
their
the higher-order
prod-
d.fterent filter
interpolawiou. to
retain
sinco
unfiltered
for category (b)
need for
of
in
widths so that
other
data,
uses
where
may have possible,
of chis paper.
good data both on
this
questions
volume, raised
the effects of curvature data in
to
CONCLUSIONS
tabulated
a result
fluctua-
to the computor may not be known to the experi-
desirable intended
are
contributions
resolution of LES methods
the
filters)
continuing
already as
of
for:
spectra
of
he needs
is
NTED FOR ADDITIONAL DATA --
the
energy
products
that this be done with sever,
when dealing with experiments
7.
reported
to make comparisons with these data on higher-order
carefully
is
which
have
higher-order
Since the spectral
Since the bandwidth available
menter, the
of
be more useful for LES modelers if
signals
V
experimenters
have proven of less value
them are often quite
ucts.
of
averages
zones
on "overshoot"
by comparison
and complex wakes.
of various flows should be consulted
in
-
layer on properties
of detachment and reattachment;
flows.
In
are needed
of existing cases.
of the free-shear
in pipe and duct
relaminarizatton;
old &nd new flows.
new experiments
and
the
effects
Improved data are needed
The comments of tihe Individual
for other cases.
For each summary in
33
-9--.........................-... ."
-
'
-- ..
"-.
.
..
.
¾*
.
.
-.-
.
-
-
-
---
.-
-
-
-
this volume,
tiny by several workers other
"ford
University,
occurs,
as it
Stanford,
94305,
will in some cases. pvove
that should
CA
important
Division,
in
of Mechanical Engineering,
Dept.
least until publication in
at
These evaluations
planning
experiments
ecru-
These longer reports can
than the original evaluator.
from the Thermosciences
be obtained
exists that has undergone
(usually much longer)
a detailed report
typically
Stan-
an open journlal
contain many comments
for flows of any given class
of
related flow-fields. For new flow cases, ing.
Current
truberances junctions,
appear to be:
instasnces of need
in
boutidary
(e.g.:
layers
!lowu,
(i)
flows with body forces;
roughness
wind flow over buildings); and (iii)
For all
elements,
wing-body
or
pro-
(ii)
blade-hub
flow around bluff bodies.
good data imply not only adherence
to the general suggestions of
this paper out Also tkiat:
(i) data-taking be carried forward, or closely supervised,
by an experienced persoiý,
i£ at all possible;
or --
is also important to consider likely next steps in model-
it
supervisory
activity
oc(:.tc
during all
(ii)
considerable
stages:
planning,
advisory
independent.
data-taklng,
and
eval-
Clear understanding of the pitfalls in various experiments is not accumulated
uation. quickly.
B. E. Launder and W. Rodi remark in the evaluation of Flow 0260:
Overall the most sui'cebsful studies have been those ur-ertaken in laboratories that have made a large .,cale effort evolving Dver a decade or more. This emphasizes how crucial design and experimental techniques have been to Certainly before anyone embarks on further obtaining really useful data. studies of the wall jet, he (or she) should read through the collected reports from Professor Newman's group at McGill (those of Fekete, Guitton, Gartshore, Irwin, etc.) to brief himself on the problems that arise and "the way that skill can overcome them. How much can be recaptured unwritten is
category
This question supplies still
always a question. review
side advisory *
from the reports and how much of this experience
(b).
can be
critical
Strong periodic
Gctutiny
in
performance by at
of
remains
another reason why out-
successful
least a few able,
experiments
for
experienced workers
from outside the institution holding the grant or contract would seem highly desirable
'
(even
though
it
has not been past practice).
Such an outside body could also be of
important service by assuming responsibility for planned replication of experiments in orderly way.
- -an
Special expertise of this so-.t on other flows exists the example is not isol4ted.
,
........-
.
.
in other research
groups;
8.
RECOMKENDATIONS FUR FUTURE DATA TAKERS IN COMPRRESSIBLE FLOWS When an experiment
defined. is
is
designed,
ca-e must be taken that
the flo-i field is
well
All boundary conditions must be specified or shown not to be important; this
especially critical for transonic flows.
rium boundary layer is also important.
The establishienL of an upstream equilib-
E9:periments should also be designed to test a
particular aspect of turbulence modeling when possible. Improvements
in
the operation and interpretation
and hot-wire anemometers
in
recent years make it
of the data from laser-dopplcr
possible
to consider these instru-
ments for gathering data of turbulence parameters upon which turbulence model improvements
can
tunnels
be made.
utilized
boundary layers
The
for
relatively
studies
of
small
fluid
models
mechanics
car. be performed with greater
layers occur on the wind-tunnel walls. tuating quantities
are
suggests
with
that
supersonic
measurements
wind
within
spatial resolution when these boundary
Redundant measurements of both mean and fluc-
are also recommended.
wall data where LDV measurements
associated
Pitot tubes should be used to obtain near-
suspect.
Continuing efforts should be made to
obtain more accurate surface skin-friction measurements.
.
REFERENCES Cantwoll, B. J. (1978).
1980,
Evaluation of Flow 0410 for this conference,
and NASA CR 3066
Chapman, D. R. (1980), "Trends and Pacing Items in Computational Aerodynamics" (In'vited paper for 7th Internati.onal Conference on Numerical Methods in Fluid Dynamics, Stanford University, June 23-27). Coles,
D. E.,
B. J.
Cantwell and A.
ted Instrumentation," Eaton, Owen,
J.
K., and J.
J.
Wadcock (1978),
"The Flying Hot-Wire and Rela-
NASA CR-3066.
P. Johnston (1980),
Evaluation of Flow 0420 for this conference.
F. K. and D. A. Johnson (1980), "Separated Skin Friction Measurement--Source of Error, an Assessment and Elimination," AIAA-80-1409.
Simpson,
R.
,. (1980),
Evaluation of Flow 0430 for this conference.
These remarks were prepared separately by M. Rubesin and C. Horstman for compressible flows, and hence overlap in part remarks above. The remarks have nevertheless been left intact for completeness and as an independent opinion. 35
1A
L.
APPENDIX 1 (From letter
Two
by F.
examples provide
A.
Dvorak to S.
the interpretation
of experimental first
In
the
distributions
Kline,
dated 15 August 1980)
substantive proof thaL the computations
disaster.
swept semlepan wing of
J.
data,
instance, aspect
only help in
but can also save a proposed experiment
an experiment
wa;
ratio 6 -it 21* angle
conducted
by
of attack.
The measured
at a series of spanwice static,ns are shown on Figre I.
Because of a scarcity of hi,, angle-of-attack thres-dimenal.onal
for
comparison
with
theory,
compared with a recently developed several spanwise stations,
"the
experimental the at
apparent during
that
the
flow calculations
part of the wing
full-scale
nel.
The
of
the
layer
tunnel
sc:ounted areq.
suggested
instance,
intermittent
of
a ccmprehensive
fuselage
model
in
investigate
ways
to reduce
splitter
floor and
data
plate
ceiling,
coufiguration
flow on
was
"odel
streamline the
in
rear
all
frontal
was realized flow.
It
is
reattachment
been
retrieved
Following
by
for
drag.
In
in
was layer
15%
order
at.alysis
to hav-3
deflecting
in
an
advance
the
floor
&a the analysis as were
of
the
effects
would
working
distributions
tuselage would
on
be
sec~tion
the
model
be greatly distorted
Further calculations 6uggestedt
the tunnel
ihese suggoerlons,
an 80%
x 22 foot VSTOL tun-
tunnel-blockage
area
boundary
36
planned
an aerodynamic
for use
that
part of the
with the theory.
14
this was modeled
plate should be discarded and
of the model.
excellent agreement
it
analysis was performed
planr.ed
order
and
test was
to validate
and totally unrepresentative of the flow in free sir. upstream
since
that
Furthermore,
fully attached
have
and
Comparisons at
separation with
wind-tunnel
two--fold:
Consequently,
The wind-tunnel pressure,
that the splitter
retrieved
thought. figures,
the NASA-Langley
the computati,,nal procedure, large
the
pree-
being fully ducum-nted.
from the model.
for.
than previourily
experimental
was
walls,
that
The
an
were
results
Figures 2 aad 3, indicating
the wing was experiencing
exp-.riencing
cycle.
results
separation modei.
were plotted on the seme
test
k
Computed
behaved
the
test of
test.
boundary the
to
time
was
helicopter
purpose
method, and unbiaseli
the
ecani-valve
"NASA--Langley and is "In the second of
better
and the experimental
experimental
two of whl.ch are shown in
results were
attacued least
the
three-dimensional
a
pressure
were discarded. data
on
Malfunctioning
blamed
for the large amount of scatter,
from
NASA-Langley
scanivalves were
sure
-9.
cannot
boundary
the subsequent
layer be removed test data wore
in
f~:ZL.-10
-8I -0
-7 U.;
CP
-6
-.
*
STATION= 0
5-s
3
0-27
00000000
.0
.~*4
.6
.8
1.
SCRT X/Cl -12'
1
-11]
-~
0
-7-41 TTOJ
-3rIN1P
76 a
000
000i000,00
-'4.
0
SC~RT(X/C)
SURTt X/Cl
-St.0
-0
Cp
STRT I0N--3
0p
-6
-2-
'rIN a
0000000000000
0-0
6
a
Q--5 1.E8
co0o *01-
o.2 .4
0,00, 000
.6 .
.8 2 1.0 SR(XC SORTX C
AL.PHA=21 .38 SWE~EP= 5.72
Figure 1.. 37
?000000
0(.!?-!
-12 r
I
-
6
4
-4
--
ci'
a~~
I-2
[A
0
a~
10
-1
SORT (X/C)
-12[
-12 -10
-4 -8
-3
-7
0
.4.I. .
4 6 .
0STRTCX/C6
SOTi'C
.
-12
-3l
-3
-7.
-7
0 ,.
*.
*
01 -6
.85
Id0
SORTUX/C)
-8
, .*
0 0 0 =
.6
SORT(X/C!
-8
.L-..
.
.
-9
-8m
I
-7
-6 cp -5
6
-
-
-
7TACHED FLOW
-
PRE~SENT
-4
SEPARATION AT
XIC
Q
-
UPPER
1,
EXPERIMENT (17)
A
-3
-2
CLUAIN
.06
LOWER
C
X/C 0
.2
.4
.6
Figure 3. 39
.8
1.0
fl
CONTRIBUTIONS TO THE THEORY OF UNCERTAINTY ANALYSIS FOR SINGLE-SAMPLE EXPERIM~ENTS IRE
Robert J. Moffat
INTRODUCTION When two "good" experiments differ, how can the significance of the difference be assessed?
When a -good" theory and a "~good" experiment diffec, how much difference
can be overlooked before one must conclude that a disagreement exists? tle hope of quantitatively answering questions
There Is lit-
such as these until the research com-
munity accepts responsibility for documenting the uncertainty In both experimental and computational work. There
Ls a growing awareness
of the need for such analyses.
Both
the Interna-
tional. Standards Organization [ll and the American Society of Mechanical Engineers [2] are developing standards ments.
for the description of uncertainties in fluid flow measure-
The U.S. Air Force
[3] and JANNAF
[4] have adopted guidelines for reporting
uncertainties in the performance testing of gas ets,
turbines and liquid propellant rock-% It seems only a matter of time before technical societies and con-
respectively.
tractirng agencies will
require
such documentation as a regular ardjunct to
research
studies. The techniques acdressed in the above references were developed specifically suit the needs of industrial performance testing--basically post-hoe operations.
to The
experiment is presumed to have been conducted, one or more sets of data are available, the average results have been computed. uncertainty
interval
which accounts "bias"
in an
fo'r
The remaining problem: assign a value to the
surrounding each of both
experiment
"fixed
errors-
is frequently
the calculated results, and
random errors."
evaluated
a single estimator
The
"fixed
by an. opinicon poll,
error"
or
querying those
with experience as to the probable magnitude and sign of the fixed errors.
There is
some disagreement in the current international literature concerning the proper way to combine data. *
the
"guesstimates" of
Regardless
of
uncertainty analyses sult.
the
fixed
errors
with
the
combinatorial scheme U-3ed,
is in reporting:
recorded the
uncertainties
principal end
use of
in the these
describing the uncertainty in the reported re-
The four references cited outline the theory and illustrate some of the differ-
ences of opinion.
Dept. of Mech. Engr., Stanford UniversiLy, 40
Stanford, California
94305.
The present paper takes a different view at experimental work and of the role of uncertainty
analysis.
Uncertainty analysis
with which a researcher can construct uncertainty
analysis
finds its most
tation,
is
servation case,
the
This is
law)
be
program.
result will
where uncertainty from the expected
estimate),
its instrumen-
seldom agree
of
engineering
(i.e.,
baseline data set).
exactly
In either result.
analysis comes in--to provide a quantitative means
for as-
(i.e.,
the achieved
then the experimental system is
If
differs
with
The a con-
the expected
result
If
development,
instrument requires calibration.
basic principles
then the experimental system is
fore being qualified.
As such,
The entire system is viewed as an instru-
or a data set of accepted validity (a
experimental
validity.
composed of an apparatus,
and this
based on one of the
sessing the significance of the difference. cantly
of provable
-.
not the reporting phase.
ment designed to obtain certain data, calibration may
as one of the principal tools
important use during the planning,
regarded as a system,
and a data-interpretation
viewed
an experiment
and shakedown phases of the experiment, An experiment
is
the achieved from it
resulk
differs signifi-
by more than the uncertainty
deemed to require further improvement be-
result
lies inside
the uncertainty interval,
"qualified," and can be put "on-line" for the produc-
tion of new data. Further benefit been qualified will probably
for
measured
experiment is
data
taking.
display scatter
trial to trial. to
can be derived
from uncertainty
During the conduct
(i.e.,
analysis of
random variations)
after
the experiment, about the mean
scatter.
If
not being
In the
conservation
laws)
is
measured
used;
scatter exceeds
the predicted
to be emphasized is
ferent purposes.
an external reference
hence
result,
scatter,
from
then the
the uncertainty in-
(the baseline
the uncertainties
In the second case,
and the uncertainties
poinL
results
:11 controlled and needs to be re-examined.
first example,
must be acknowledged. cy,
the
The scatter can be predicted using uncertainty analysis and compared
The two uses mentioned above require different estimates of terval.
the system has
in
the
data set,
instrument
only repeatability is involved,
in the instrument calibrations
or the
calibrations
2
not accura-
should not be included.
The
that different estimates of uncertainty are needed for dif-
Later in this paper a classification of these types and their uses
is discussed. A word of caution is *
familiar with either 3). class
Those methods,
in
the NBS
order,
at this point,
method or the Air Force method
and their dertvatives,
use the
of fixed errors present in an experiment,
from the random errors, fects whose values will strument
calibration
directed to those readers who are (both described in Ref.
term "bias" error to designate a
and treat the bias errors differently
called "precision" errors.
The "bias errors" include all ef-
not change during the course of the experiment,
defects,
or fixed
environmental
errors
(such
such as in-
as the radiation
41
*+f.-.21
jzqI. +,::.:
:1 -'
"
error of a temperature sensor) whose magnitudes have not been accounted for by a "best estimate."
The bias errors are kept separate from the precision errors throughout the
calculation of uncertainty until the last step. and are viewed as "non-statistical" in nature.
The present approach
differs from this in
here that every acknowledged "fixed error" is
a fundamental way.
from a Gaussian centered'
assumed
solely due to the
likely to be positive or negative,
possibilities:
in the following paragraphs.
centered" is If
distribution of
is
accounted for, using the best available
estimate of its value, and that the remaining defect of knowledge is uncertainty in the corrections--equally
It
and coming
a state described as being
The hypothesis that the experiment
"zerois
"zero-
then tested by comparing the achieved results with the expected results.
the achieved and expected values agree within the predicted scatter,
no visible evidence of the other hand,
if
residual
error in
the achieved
result
cantly more than the expected scatter, zero-centered":
there
the experiment:
differs
diagnostic studies are required.
is
"zero-centered."
On
from the expected result by signifi-
this indicates
remains an unrecognized
it
then there is
that the experiment
error somewhere in
is not yet
the experiment,
As a consequance of this approach,
and
the final experi-
mental result should not contain any significant bias error--only precision error--and the question of how to combine bias and precision need ,iever be addressed. ent
method
of
experiment
development
is
well
ed
st.
to
research-type
where the experiments are relatively simple to evaluate and repeat. there
tions
is
no
need
should be corrected. ature is
concerned,
to
tolerate
"bias errors"--once
they
The pres-
experiments,
Under such condi-
are
recognized;
they
Large-scale engine tests, however, with which the general litermay well have to put up with these estimated errors and continue
to treat them separately. In
the following analysis,
pendently;
there is
it
is
no averaging.
presumed
that each data set is
Each data set is,
therefore,
processed
inde-
a true single-sample
ixperiment. The uncertainties *
Worst Case
-a
in data can be propagated
combination or a Constant
into the calculated result either by
Odds combination.
The
latter is
-.
emphasized 1 4
here.
* .
The mathematics of single-sample uncertainty propagation were described by Kline and McCl.intock
(5] and have been practiced widely,
ent paper builds upon that work,
9.J
if
sparsely, since then.
The pre3-
adding three elements to the structure:
*
The concept of Replication Levels, to distinguish the treatment of scatter on repeated trials from differences of results between independent experiments.
'
The concept of the rors.
"*
A technique for executing uncertainty analysis on computer-based datareduction progrems which required only a small amount of programming to obtain an uncertainty analysis on even the most complex program.
Zero-Centered Experiment,
-
having no residual fixed er-
42
,•±-
-trr
.,y.
r--t.,
:-.
N-*,
j
-.
.-
-S
.
.
.-
L _1
The mathematics will be reviewed,
along with
and then the new elements discussed,
some examples of the use of uncertainty analysis. THE PHYSICAL PROBLEM are often affected by more variables
processes
Real
Most data-gathering experiments are designed as "partial derivatives" of
acknowledge.
holding all other aspects ostens-
some process with respect to one variable at a time, but rarely are
ibly constant;
the background conditions truly constant.
test conducted as a true "partial derivative."
Rarely is
a
Often there are secondary variables,
which are varying randomly during the course of the
not observed and not controlled,
Such background variables can cause changes in the result ef an experi-
experiment.
all of the acknowledged independent variables are held steady.
even if
ment,
than experimenters wish to
The appearance of unexpectedly large scatter in experimental results is one warning of the presence of such uncontrolled or uncbserved variables. THE BASIC MATHEMATICAL FORMS It
val,
assumed that each data bit will be described either as in Eq.
with an assignment of the best estimate,
below, 6
is
xi or 6xi/xi,
x
,
(Ia)
or (Ib)
the estimated uncertainty inter-
and the associated confidence level or odds.
Absolute Uncertcinty:
x1
x Best
( a)• ()
(20/1) Odds
Uncertainty
Interval
Estimate Relative Uncertainty; x
-
±
i
ii
Odds
Uncertainty Interval
Best Estimate Consider a result R,
(1b)
(20/1)
6x /x
calculated from a set of values of the xi.
the method of combining the uncertainties.
As a consequence of The
there will be an uncertainty in R.
each of the x,,
case combination and constant odds.
One must choose uncertainty
Two logical options exist: worst
The combinatorial form for each is shown below:
Worst Case:
6R DR .
1,
l' 1
1I~I
-ax
R 26 2
R 6x
+ I ax
Constant Odds: '-2
2 1/2
2 ax.6RXN, ix
x
D
43 •-."
•':_-1
•
in
),+(D
(3)
Kline and McCliutock
(5)
have shown that 2q.
(3)
ansesses
good accuracy for most functions of engineering importance.
the uncertainty with
There are three restrlc-
tions: 0
Each of the xi must be an independent variable.
0
Each of the x, must be from a Gaussian distribution.
0
The odds must be the same for each 6xi statement.
Aa a consequence of Eq. stated for
20/1
odds,
(3),
If
the uncertainty intervals for each of the x.
the calculated value of
6R will also be appropriate
are
for 20/1
odds. For most single-sample third restriction, kiu.rictiou,
it
experiments,
therefore,
the
6xi are estimated by the observer.
serves mainly to guide estimation.
The
As to the second re-
seems acceptable to presume that most instruments produce repeated val-
ues with a Gaussian distribution, Instruments.
but
there is
little
proof of this point for modern
'Tho choice between Worst Case combination and Constant Odds is usually made based upon the consequences of being wrong. for failure
is
extreme,
for most situations,
.
There are a few situations in which the penalty
and where Worst Case combination would be recommended;
the Constant Odds method
is
preferred.
but,
and yields a more useful
result. When the result is
calculated ns a product string, it
is particularly easy to as-
seas the relative uncertainty:
R
If
a b c xbx
-
'
1~ 23
te
then"
Equations
(3)
ann
6x,2
{(a
R
(4)
x
22 21/2
+
-j
x2
are the basic working equations
They pose no particular difficulty in evaluation, able as to the values of the certainty analysis: will address experiment,
(4)
+
6
xi.
of uncertainty
providing that information is
avail-
This proviso points to the critical problem of un-
identifying the appropriate values for the
this problem,
analysis.
and introduce
as a way of classifying the
the concept
of
6
x1 .
"replication
The next section levels" of the
6
x ..
If the 6x1, are taken to be variances, Eqn. (3) holds without the need for a Gaussian-distributed population. Equation (3) is an adequate approximation for any reasonable underlying distribution so long as the 6xi are independent (not crosscorrelated). 44
+2
REPLICATION
LEVELS
The Root-Sum-Square way to combine agreement
combinatorial scheme
uncertainties
The
odds (1,2,3,4).
to evaluate
the
the
the same exper-
In
One
use of uncertainty
repeated trials
such an application,
analysis
is
with the same apparatus
the
instrument
calibrations
since they do not change during the conduct of the experiment. Replicaat that level, does not involve the instrument calibrations.
experiment,
other
hand,
if
ther, conducted in tions must
interval.
of the scatter in
instrumentation.
no rolE,
tion of On
the significance
same
some dis-
the end uses of an uncertainty anal-
one lets
ysis guide the selection of uncertainty
play
however,
which describes both types of error.
disagreement can be obviated if
and the
There is,
appropriate
on the part of some testing lahorator-
arises from a desire,
to present one number,
ies,
generally accepted as the
as to how to deal with "fixed errors" and "random errors" in
This disagreement
iment.
at constant
is
be
one wishes
a different
considered.
two or more experiments,
higher-ordered
to compare
laboratory,
If,
at
this
the
results
of
one experiment
then the uncertainty
point,
one
imagines
in
with
instrument calibra-
an ensemble average
each conducted with a different set of instruments,
replication
involves
Instruments
having
ano-
then this
calibrations,
and
will usually show a larger scatter--an ensemble average over several experiments,
and
its
larger
ccmparing
uncertainty with work
at
experiment has been been corrected
interval,
is
another
the replication
laboratory.
"zero-centered,"
for by
As has been mentione-d
i.e.,
In
level which must be considered
both
that all
cases,
it
recognizable
the best available estimate, earlier,
different
over
is
assumed
so that only uncertainties
viewpoint
necessary
combine
"fixed errors"
errors."
The concept
the analysis, experiment
of
the
establishes
with
level
levels
different belongs:
absolute for
question of
different
simultaneously
one concerned replication
of
remain.
this state can be apprcached using uncertainty analysis
present
treatment
the
sources of error have
to guide the development of the experiment. It vill be apparent, on reflection, that the a
that
in
of
to
replication,
ensemble averages one concerned
accuracy.
purposes
how
of
There
experiment
is
according
has
to
rendered and
un-
"random
the end use of
to which each realization of
with scatter further
planning:
on repeated
utility this
in level
trials,
the and
defining a third involves
only
the
instrument capabilities. Three bered
orders
according
of to
replication the
level
additional
are defined
degrees
of
in
freedom
the
following
whicb
the
paragraphs,
conceptual
num-
ensemble
average adds to the experiment. Zeroth the only
display
Order of
is
described
by
each
instrument
is
component of uncertainty at
the
following
con.ic'ered this order
to is
conditions:
time
be
under
invariant
itself
is
frozen;
replication;
the interpolation uncertainty,
the
i.e.,
45
..
.
.
.+.
the inability of independent hum.n observers to assign the same numerical value to the displayed xi.
The values of uncertainty at this level are often assigned as "one-half the smalThis order of uncertainty is de-
lest scale division" or some similar rule of thumb. noted 6xiO. First
Order:
display
the
running,
At
stationary mean,
this order,
time
is
only
variable;
with
the
experiment
to vary stochastically
assumed
is
instrument
for each
the
about a
The First Order uncertainty interval includes the timewise vari-
xi.
The value of uncertainty at
ation of the display and its interpolation uncertainty.
this order is denoted 6xiI and is usually larger than 6xiO for any real process. changes in instruments are considered at this level.
No
observations of
the
the
within
of x,
value
from a set of repeated
6xil, can be estimated
The value of
operating
apparatus
its
at
The intent is
in the mean during the observation period.
estimate
the
of
standard deviation of a sample of 20 elements,
important
is
each xi is
to note
A diagnostic the
should
The ;alue 6xI
[6].
odds of 20/1 are desired. for 20 diagnostic observations of
the requirement
that
not synonymous with taking 20 repeated runs on each set point of an experiand should be done
The diagnostic observations of xi may be taken very rapidly,
ment.
of xi from
possible values
S2 0 , is within 5% of the standard devi-
: 0.96o according to Thomas
be taken as 2c, or 2.083 S2 0 , if It
to arrive at a valid
For a Gaussian distribution,
sample of 20 elements allows a confident estimation.
ation of the population (S20
for any monotonic
will be taken.
experimental observations
(single-sample)
future
which
the population of
deviation of
standard
The set of readings
operation or should be adjusted
should be made during steady-state trend
set point.
at least once during the testing program for each point, experimental
range.
The principal limiting factor is
or a few points spanning the
that
the period of observation
be representative of steady operation. Just as statisticians menters
frequently
frequently permit the use cf "pooled variance,"
so experi-
on an apparatus--relying
upon prior
will pool
their observations
It is experience and a brief period of observation to assign the values cf the 6xil. probably not justified, in terms of the effort required, to do a full statistically L
The basic method has a sound, statistically velid basis, valid work-up of each 6x,,I. If the and small errors in the estimates of the 6xil, will not defeat the objective. labor involved abandoned,
then more is
is
treatment
in a "rigorous"
so
formidable
that the entire effort is
good judgment had been used to execute a reason-
lost than if
ably accurate analysis. At this order time and the inSLkument
Nth Order: variables. been
each conceptual
For
replaced
by
of
another
replication,
the
type.
same
each
identities are considered
instrument
This
makes
Is considered "instrument
46
S-----
.
.
..
%
-
-.-
.-
.,
to be
to have
identity"
a
..-
6
The Nth order uncertainty,
used.
due
the uncertainty
introduces
and
variable,
xiN,
the
to
always larger
is
of
calibration
instrument
the
than the Fitst Order uncer-
tainty. will be shown in the last section of this paper that,
It
for single sample situa-
tions: -
x
{dxi2caI
+ (6x
(5)
)21l/2
where 6
XicaI
-
the 2o value for the ensemble average of calibrations of instruments of this type, for
the 2o value
6x,,-
observed on repeated
uncertainties
the stochastic
observations. There is
an immediate and very practical difficulty with erecuting Nth Order unmanuCacturers of instruments do not describe the uncertainties in
certainty analysis: their products in
"sign the
the appropriate terms.
%•'
is
the generation of a complete output- .nput response surface).
effect of identifying the individual inst-ument,
"the standard instrument
This has the interval of
to within the uncertainty
instrument used in the calibration.
than about 1/3 or 1/4 of
instru-
one can call for a detailed calibration of each i
(i.e.,
that uncertainty interval is less
If
the stochastic uncertainty in
6
the reading,
xi,l,
then the pro-
A complete data-reduction
calibration can be regarded as "certain."
one which includes detail~d calibration curves for every
gram,
to as-
necessary for the experimenter
calibration uncertainty, based on whatever evidence can be assembled.
In critical situations, ment
It
instrument,
could
then
revert to a First-Order estimator and be subject only tc First Order uncertainties. Each the
replication
experimental
level
(Zeroth,
uncertainty
First, 6RI,
(6RO,
and Nth)
and
RN).
yields a different These
have
estimator of
different
uses,
and
quite properly have different values. Uses of the Uncertainty Estimators of Various Orders For every use,
the principal feature
is
ment and the uncertainty analysis to improve
".
certainty analysis allows at different
"parison of warning.
tion,
the control of the experiment.
The un-
the researcher to anticipate the scatter in the experiment, levels,
based on present
inderstanding of
the system.
the achieved results contain no more deviation than predicted, indicated.
this constitutes
unobserved
iteration between the experi-
Coa-
the achieved result with the expected result then givrs either a check or a If
coutrol is
replication
the same:
If
a check of
the achieved results contain more than the predicted
a warning
element which is
that
the
experiment
causing significant
contains
some
devia-
uncontrolled or
error; the experimenter can then take
steps to correct the situation. 47
•
..-
-.
In the following paragraphs,
the principal uses oe each replication level will be
discuased. Zeroth Order.
The calculated
which could be obtained.
If
value 6R0 representi
trials would lie within * 6%O of
their mean,
experiment could do better than 6RO. used as a planning tool, " :as
-
unsteadiness in
has been
the process.
put
variable.
ments will be steady du.
4
assume different values
on repeated
.
than
1/2 SRO
"
includes lack of repeatabiliiy
If
then it
if
this is
cannot be achieved at
repeated
tr1.ls
the standard
When this situation occurs, but
is
trials
sensitive
reduction program.
deviation
of
the
is
to
results
is
reduction program are necese.-,
developeient
Aa an example,
Unstealin,ýas in
(reflecting,
experiment). tic
on
larger are
than 1/2 5R,
not
effects
this sens.'
If
tie standard devia-
then the process being
being accounted
the
test
facility,
ý.-'. Lhe momentum t~leckneas ,.1±y MCasuremi~nts--•.oL
turn,
inherent due
estimates
Lhav.ge% 4n
in
n-uient
seauring
to
the
density
a
standard
for
in
the data
is a darning to tle experimenter that diagnoscontel
procedures,
or
data-
of a boundary layer was being
accounting for density variations
temperature
Actual results on succeat: "- trial.
uncertainties
recorded-
in
larger
The standard deviations of repeated
within the boundary layer which might be caused by small variations ture
"
work
supp,•
calculated based only or
.
'y
wnich
Such an occu:rrence
*
*-
sizmificantly
th* data reduction program were sufficiently com-
signific-n variables
tic
and
instru-
in start-up or reset control.
Itmewise unsteadiness.
-\[<
tests
fne observed
the dependent variables will
plete to acknowledge each physical mechaaism which affected R. repeated
may be oc-
trials, even though the tndependcnt variables are
trials would be equal to 1/2 "P 1 if
observed
scatter
be expected on repeated trials with the apparatus at hand,
considering its documented
tion of
eince it
The calculated value of 6RI' the First Order uncertainty,
the scaLter in R which mw '
-,
display
evidence thit tihere is significant
then one must suspect a hidden variable.
Firpt Order:
*
"on-line,"
ng each observation period,
constant.
.
mairnly
the desired result cannot
The unsteadiness may be concealed,
held
*
If
pi cision at Zeroth Order,
larger than ± 6R0,
curring in an unobserved
-
No real
all, and a different experimental approach should be selected. Once an experiment
.
95% of the time.
The Zeroth Order replication concept is
being sufficiently readahle for a planned experiment.
which is significantly *
approximately
in R
the results of repeated
as one criterion for accepting a proposed set of instruments
be achieved with sufficient *'
thie minimum uncertainty
the process were entirely eready,
of wall tempera-
during the conduct
of the
would include not only the stochas-
valocity
and
differences.
position, As
a
but
also
consequence,
the
the
un-
actual
results
would
1/2 CI"
This would be the warning that some mechanism was acting which was not being
display
deviation
greater
than
the
predicted
value
of
accounted for. 48
;2"
I
of an experiment, titative
tool
when
for
the test system is
deciding
chiefly useful during the debugging rlAse
interval is
The First Order uncertainty
when
the
being developed.
experiment
It
is
sufficietitly
is
the principal quanrepeatable,
that
is,
than
ex-
well controlled.
based on
pected,
trials
the First Order
uncertainty
predicted,
a warning that unob-
is
.
tests should
Diagnoctic
that mechanism
identify the mechanism involved and to acknowledge
to
then be conducted
this
the outcome of the experiment.
affecting
larger
significantly
on repeated
are
served variables
is
deviation
the standard
When
in the data-reduction program. When the standard Order
then
prediction,
uncertainty
repeated trials
of
deviation
there
is
no
is
further
repeatability phase of development of the experiment
be
justified by
observations
than necessary
then
minated
while
the
program.
If,
repeatability
is
still
on the other hand,
the
may
Nth Order:
never
tion,
If
the
6x ,, are
described
by
6xi are set unrealistically
be achieved.
Appropriate
values
complete.
A
taken
development
diagnostic
incompletely
The calculated value of
every
instrument
mates the effect the
First
exreriment
"true"
for
larger
may be ter-
its
data-reduction
low,
the," a check on
the
6xi,
are
thus
the
to
were
upon R of
Order be
the
exchanged the
the Nt)'
compared
for another
(unknown)
component.
results
significantly, the
one of
6RN,
Order uncertainty,
The
with
Nth Oider
those
unit of
calibrations
the
for each observa-
same type.
This esti-
of each instrument,
calculations
fr)m another
if,
estimates the
allows
ostensibly
in
studies
similar
one,
addition from or
one with
values.
If
two
compared
with
experiments
are is
unmeasured differences
in
their
repeated invoked
trials,
in
error.
initial
It
one
or with the frequently
taintLes beginning.
yields In
will
intervals,
situations;
or
might be generated, free-shear
then (ii)
help
in
developing is
disagree either: at
least
for example,
by
layer. accuracy
Fir t Order will suffice to describe scatter on
to
be
an
experiment,
compared
with
but
Nth
another,
Order
must
be
with
computation
t•tbration
uncer-
truth." that
large
such cases,
tnclusion
value the
for
only
of SRN
all
of
that
recourse 49
S°
a
experiments
calculation must be used wherever the absolute
experiment
occurs
such a
different
Condition (i)
condition3 in
identical)
uncertainty
Ordtr
studying
to be discussed.
and
whenever
analysis,
is
Nth
actually
The Nth Order uncertainty the experiment
(but nominally
from two different
the experiments
of
and the
thp
difficulty:
xi be net as small as can
R which could be expected with the apparatus at hand
scatter in
(i)
experiment
6
for the
actutl apparatus. large,
of
problem of experimental control.
critical
to
on the
SRI will be too
evidence
can be considered
that the First Order intervals
's important
It
close to the First
acceptably
is
the
instrument
the experiment to
reduce
the
seems
doomed
Order
from the
uncertainty
intervals
by detailed
implication easy
to
ment,
of Eq.
calibrations
(3)
identify,
Is
and
that
should
any term smaller
of
the
the most
criticpl
uncertainties
receive
the most
with
than 1/4 of the largest
value, -
the
then
experiment
predicted
the
experiment
returns
the
data production. .
values known. *.
uncertainty
If
"true"
not,
be
may
6
then
The principal
RN
6
of
RN,
"truth"
of
been
it
improveThe same
(5). reduced
may be
to
an
acceptable
"true" values.
If
considered qualified
is indicated.
are those
are
the for
There are few "true"
described
as Basic Princi-
ples: The Rate of Creation of Energy The Rate of Creation of
of
a
momentum
mass,
or
energy
]edge
of the expected Nth Order uncertainty,
reach
any
conclusions,
observed
the
ability
value
and
the
*
tainty analysis provides that ability. the absence of an applicable
a secondary
check:
so well
the field.
stood
the
test
Knowledge of
necessary before
the
of time that
the Nth Order
significance
-.on an apparatus,
an essentially to
assess
expected
Basic Principle,
a baseline experiment.
validity
uncertainty
of any difference
without know-
useless enterprise. the
value.
significance The
Nth Order
is frequently
one
A baseline its
EF +
J
balance
is
have
difference
has
the
must
"
In
between
one
c
-
0
-
The Rate of Creation of Entropy ) Execution
0
-
+x Momentum
The Rate of Creation of Mass
-i
each stage
some known
further development sources
At
by Eq.
has
against
value within -
important
term can usually be ignored,
interval tested
An
large elfect on the outpu,
attention.
remark applies to calibration uncertainty as indicated When
instruments.
experiment is
is
accepted
intervals between
forced
of
To the
uncer-
to use
a data set which
by most workers
in
for both experiments
is
the observed and expected
values of R can be assessed.
DEVELOPMENT OF A ZERO-CENTERED EXPERIMENT Industrial
performance
rors" and "random _
tunity
-
testing,
errors"
in
the
experiment
results
may
be
trials
Many research tests,
is
faced with
the uncertainty
to revise
many repeated
nostic
testing
structure
allowed
to
descriptions,
to remove
the
residual
bias
retain
(an Nth Order replication) experiments
the problem
of combining
because
there is
fixed errors. such
might still
that
be in
In
even
etc.,
and
no oppor-
the
mean
the experiment
can be considerad
Nth Order uncertainty
to be substantially
free
Such an ideal state can be called a Zero-Centered experiment. The goal of most research is
to conduct Zerc Centereo
50
.
.*
......................................
.. -
of
error. and diag-
analysis until
the experimental value agrees with the true value within the expected uncertainty. such cases,
er-
industrial
can be refined using instrument calibrations,
such as energy balances,
"fixed
.^periment8.
In
of fixed error.
p
UNCERTAINTY ANALYSIS ON COMPUTOR-BASED It
is
impractical
to
relatively simple cases. to the
data
and use
the program.
In
is
as
vided
regarded
data
for the
as
subroutine,
in R.
A Jitter
1.
any
example
nF
computer
reduction
be
to
called the
illustrate
calculator.
this,
this
A
operation,
lim i
data provided. new value, value of using the "R/3xi *.
q
-
AX-~
the program
1hen the first
is
value of
may be used.
Using
calculated, 6
xi
estimaies
a
data.
Jitter
If
Program,
since
it
typical
the
provided.
which
pro-
program
Program
a
to
the main
is
shown
illustrate
hand-calculator
can
in the
handle
The central argument is
is
uncertainty
simply controls
TI-59,
are
sequentially
the
to
Jitter
calculator,
xi
but the flow diagram would be the same
ex(6 i
xl,
a
for
data-
that:
x
(6) Ixi.
t
x x
is indexed
difference
Either is
6
the
the main
contribution
by a
(RI-Ro),
and the contribution to 6x1
This process
of
calculates the best estimate,
variable,
R1 , calculated. iR/3x 1
first
than the
-R i +
ax i
the
a
simple
R
-
by
for a hand
Even
but
integration within
program might he larger
the usual
program involving up to ten variables.
OR
In
or numerical
resulting
the .Jtrter Program approach, or
if
be very complex,
written
any
to do uncertainty analys1s on amiy computer-based
addition
not
for
burden on the experimenter.
computes
To was
in
analytically
programs may involve many corrections
look-ups
how complex,
can
and
program.
T1his
compactness
it
Program need
data-reduction Fig.
matter
program
bit
input
each
indexes
however,
no
analysis
the uncertainty-analysis
an unacceptable
program,
a
uncertainty
forms or table
such cases,
a simple matter,
dat.-reduction
DATA-REDUCTION PROGRAMS
an
Complex data-reduction
implicit
main program--certainly It
execute
forward
repeated
Ro,
using the input
small awount, and the
is
or central
cxl,
value of
and a
Exl,
the
found from (3R/Dxl)(6x 1 ) difference estimators of
for each variable,
and the contributions
squared and accumulated. The
values
of
estimate
of the
true value of the
Fig.
On the other hand,
I. Once
the Jitter
the
may
it
Program
Sensitivity Coefficients, the relative
exi
is
be
taken
arbitrarily
aR/ýxi will be often justified
has been
installed,
small, found, to use it
is
the individual contributions
and absolute uncertainties
in
Ps
in
cxi
in
which
case
the
the case illustrated
the results
51o
in
6xi.
a simple matter to obtain to
best
-..-Lall
...,,rcr! -. r,
the lnd
i2. x -Sensitivity
Coefficient
-
x-Contribution
A(R/;x
Relative Uncertainty
-
6R/R
Absolute Uncertainty Such
a
program
data-reduction warning
flags
ability.
need
program
only
as
a
triggered by
They advise
this procedure
6R
devijed
routine
once
the ucer
that
and
addition.
high uncertainty
bles producing unacceptable out
be
)6x
the
can
then
Graphics
be
output
incorporated
in
each
with error
barc
and
values are obvious extensions of this cap-
experiment
output uncertainty
has moved
into ai region
of varia-
(as often occurs at some point).
With-
such regions are easily overlooked.
DEFINING TEE Nth ORDER UNCERTAINTY IN A MEASUREMENT
The intent of the Nth Order uncertainty estimator is to account for both the uncertainty of the calibration and the stochastic uncertainty due to unsteadiness. Consider some
the
reading of
observation
period,
a single
about
a
instrument.
mean
value which
reading can be described as a function of time,
xj
It
is
may
presumed or
to fluctuate,
may not
be
correct.
as:
x Fjf(t)
(7)
where x
-
Fj
the "true" value, a calibration x - x F,
presumed constant,
factor of the instrument,
where
x is
so defined that
the mean value of a large number
of observations with the jth instrument, f(t)
-
a
temporal
instability
function,
having a
time average
value of unity, xj
'ilie time-varying
indication of the jth instrument.
Consider now a single observation of the jth instrument--the
xii where IN
f(i)
-
the value of f(t)
The relative uncertainty
6.X I'. " It
x Fjf(i)
at in
Ith observation:
(8)
the instant of the ith obse~rvation.
xi•j
.SF
can be written formally as:
2
.6fjij +
2 1/2
Lfki,
remains to show that this form has physical significance,
52
(9) and utility.
over The
The 1.000,
functions
with
standard
normal
that
mean.
It
of
is
f(t)
can each
these
describe
there
"1alur nf
and
distributions
deviations
manufacturers and
Fj
is
about
be
regarded
this mean.
functions.
It
the mean calibration
a
normal
also apparent
n' Fl,,otuatinp
Let
can
be
a
.Fj and safely
mean value which 61(t)
of
the
equnl
assumed
their instruments
of
distribution
as having
individual
twice
that
is the
-. 1
instrument
as well as possible,
calibrations
around
the
that the observer will make every effort to record the mean
seq"""' ..
z,
r -:'.
i(L),
..
an average,
will have a value
of 1.00. these assumptions
If tiun of
the individual
are
correct,
then
instrument used,
6F
stands
and 6f(i)
for the uncertainty
stands
in
calibra-
for the temporal component of
the recording uncertainty. (9)
Equation
for
accounts
thus
the
a
in
uncertainty
overall
single
observation
from a single instrument. the terms
and interpreting
Rearranging
[6F {(X
where
x
Fj
-
Fi.I.'
i,j
the
Žf(i)
i,j
+
(10))f(i) (x10 .~ .
F"_j
in
the
SFj/Fj;
zhe uncertainty
-
f(i)
2 1/2
~ Fi
uncertainty
calibration and x
,,2
1
jj
value
i.e.,
in
the
of
caused
xjj
by
the
uncertainty
in 4
6xi,cal, value
of
xi,j
caused
x~
i.e.,
term;
instability
the temporal
treatment
the current
for single-sample expe'iments:
of the Nth Order uncertainty estimate
6X
the basis for
shows
by
the uncertainty
in
"
oxl
i
This can be written as:
Once again, facturers
are
it
.
=
i,j must
reluctant
be to
i,cal
•
emphasized describe
their
experimenter
must simply estimate this
hints
manufacturers'
is
in
the
better than total
Applications
product
term,
literature.
all
computation
is in
hard to such
identify.
terms,
and frequently
based upon experience
As
already
suggested,
Most manu-
or,
use
of
at best, such
the
a few
estimates
lack of uncertainty analysis.
the
experiments
would
the case
for
most
analysis
for
complex
established
ýxi,caI
for the Comparison of Experiment
Ideally, to
that
(..) ).
2Jl/2
l ,2 + i6x i(
have
values
sets,
experimental
of
strongly recommended
data
6RN
9
used as the basis for model formation and comparison
well-esLablished
existing
and Computation
values
partly
because
programs.
become
Given
feasible
as a criterion
of
for
A•,,. of
the
future
In the
reality,
this
difficulty
r-,'thods "record"
for acceptance of such future
of
is
not
of doing
this
ps-Pr,
experileimts
the
well-
and
are
"record" data.
.- 1
53
-.
¶
"
-.
-..
.
.
.
..
•
.
..
•.
.
-
-
-
..
.
.
•
/..
.'.
•'
-,
.
,.
.
.-
-,• _-
,
.
L.
values
When well-establ.shed ment
between data sets
more
clear-cut.
of the
ent
for
the
the two are
but when
difference larger
in
that,
remarks
These
is
agreement
other,
cart
band
has
others,
been and
the
beyond
The
that
If
established.
two
the
value
HRN is
is
programs; some
are
relevant
test.
points
where
For
Lhat
and
consistent, than
.
significantly
the
known.
are
the
the root-sum-square
If,
can be extended.
the same princit)p]
within the uncertainty band found from forN all
6R
three
or
each other within
reduction
6
one
mean by more
from th,
of
6RN
results
Gie data lie
all
When
larger
the
more
general be differ-
in
and
by
largcr thnn 1.4 6RN Indicate
the
NI
6Rq will
instruments
the
wherever
conclude
sum-squares
agree with
the
variabl2.
than two data sets,
more
of
square-root
than
not differ
data do
the
disagreements
point
a group of seven data sets,
the
and
different
value does not differ
When there are in
by
for the two data sets.
6R
the same,
diragreement
one
found,
to
or uncontrolled
point
apply
correct
presumed
owing
roughly
experiments, the
and computation becomes both easier
for the two experiments.
5R
experimentu,
two
"agree" when
sets
assessment of the degrce of agree-
are known,
and between experiment
Two data
root-sum-square
of
of
the
nets,
the
have
sets
that uncertainty,
a
then
correlation
a
S5RN
smaller
than
tighter correlation
the band
can be formed. of
computation
with experiments
between
computation
and
Comparisons differences data are dure.
to
attributable
When the same,
or rough estimates of
only partial
for
have
As noted above,
this
model
or
the
for
6RN
numerical
the
proce-
large
uncertainties, in
when
fact
the value of
less than
are known,
6R
the principles
remain
of criteria
for
J
case by case.
pape:
in
is
application
the data can be tested against known theory,
as
and left-hand side of the momentum integral equation
it
they
6RN must
the terms in
of some of
Since the measurement
three-dimensional,
agreement might
of
the methodology
a check of the right-
shear layers.
the
to use judgment
becomes necessary
but it
for example
amount
the
either
of
'.
evaluating data sets.
typically
in
approximations
the value
exceed
that
that
on the assumption
proceed
V.-J
Another use
for
experiment
could
would were
be easy
to conclude
the momentum equation that
disagreement
Specifically,
not.
as agreement,
be regarded
flows were
the
even
though
by
an
the dis-
The methodology of this paper can be applied to make such
look large.
judgments both more specific and more meaningful than has been possible
in
the past.
CONCLUSION analysis
Uncertainty and developmental
is
a
diagnostic
powerful
phases of an experiment.
rational evaluation
of
data
checking computations against
sets,
tool,
Uncertainty
to comparison
of one
useful
analysis
during is
the
planning
also essential
data set with another,
to
and to
data.
54
1 *.
"
*.
"
r
" -.
'*"
'
-..
'-
.+
-
"*
_* - -
+
.- -
2
~~.e
of
levels
conceptual
Three
can
replication
Order. These levels of replication admit Zeroth Order:
be
of different
First,
Zeroth,
defined:
Fnd Nch
sources of uncertainty: .
6
Includes
only interpolation uncertainty.
*
Useful chiefly curing preliminary planning.
A.1
First Order: a
Includes
*
Useful during the developmental phases of an experiment, to assess the significance of scatter and to Jetcrmine when "control" of the experiment has been achieved.
unsteadinesa
effects,
as well as interpolation.
Nth Order: Includes instrument calibration iness and interpolation.
uncertainty,
as well as unstead-
Useful for reporting results and assessing bdifcerences between reslts from different tween computation and experiment...
the significance of experiments and be-
*
0
T
,,-.'
.The basic combinatorial
equation
,D .2
The
process
sequential reduction •
.
jitter program
separate analysis.
is
4-
easily
package to
is
DR
adapted
,
the Root-Sum-Square:
6. 2 to
the
The additional
...3R
"
computer-based
can be written in
execute
222
standard
uncertainty computing time
data
reduction
programs.
A
form which ,,ses the existing data
analysis, is
1/2
obviating
the
need
for
a
usually not excessive.
REFERENCES 1. 1
International "Measurement Measurement,"
2.
ASME Committee MFFCC SCI, "Fluid Flow Measurement 1980," American Society of Mechanical Engineers,
p.
Organization for of Fluid Flow ISO 5168-1978(e), p.
Standardization (ISO) Standard Estimation of Uncertainty of a 8.
IS0-5168, Flow Rate
1
Uncertainty--Draft of 26 March, Codes and SLandacd Department,
14.
L• 1.4
3.
USAF AEDC-TR-73-5, 755356.
4.
JATNAF, "ICRPG Handbook for Estimating the Uncertainty in Liquid Propellant Rocket Engine Systems," CPIA Publication
3.
S. J. Kline Experiments,"
6.
Thomas, H. A., in Marks Mechanical Engineers Handbook, Sixth Edition, 26, McGraw-Hill Book Co. (1964 printing, ed. T. Baumeister).
r7I
"Handbook
and F. A. Mechanical
on
Uncertainty
McClintock, Engineering,
in
"Describing Jan. 1953.
Gas-Turbine
Measurements,"
AD
Measurements Made with 180, AD 851127.
Uncertainties
in
Single-Sample
Ch.
17,
p.
55 -45
-----
6[
SSTART
* READ
GO TO SUBROUTINE Ff(x 1 1 ... ,x.)
I 0
i 6G
INITIALIZATION-
CO
t
_
_
TO _
__9
F E E
( L
6C
i
6X
2
SROiN
SUBROUTINE --
x
i
f ( x l .... l Xi +
..
-6x
x
Ci ) .... Ix
- •
6G + E -I.
Fx
YES
NO
6F
PRIN T F, 6F
S TOP
Existing data-reduction routine for calculating parameter F. Fig.
1.
..
Flow diagram for jitter
program.
56
-'-
___ -
_..__"_.
2•
THE DATA LIBRARY
Brian Cantwell
INTRODUCTION
I.
One of recommended
the
tasks
major
flows.
The
for
a
broad
data
range,
taking
consistency
and
from
sources
many
reduction,
ani completeness
in
the
of experimental
Cormatted and plared
data
is
conference
1980
library cnrnIerc
which has been organized, covers
the
of
an
with
many
the information
which has
been largely an organizational
required
to organize data sets to follow a common format. by
any way.
been
have
thicknesses
left
to
the
achieve
been placed
not been
Use of the data to compute stress profiles,
cients,
using many
one and often considerable
the 1980 conference
flows
techniques uniformity,
onto
tape.
The
ingenuity has been
enhanced
pressures,
of
Although the data
been made to
task has
The data as accepted
tape.
geometries,
has
library
a
data from a variety of
onto magnetic
attempt
of
creation
or altered
skin-friction
in
coeffi-
or any o~her quantity not explicitly provided by the evaltiator has
computor.
MoLeover,
no
smoothing
or
interpolation
algorithms have
been applied to the data. At
the
very
least,
the
data
library
access to data which are also accessible be more than a mere convenience. format it
.
gathered
can be a
in
one
source of
place,
It
and,
inspiration
is
in
to
provide
other forms.
computors
Ultimately,
with easy
the library will
represents a growing string of useful data like any organized
and new ideas.
juxtaposition
The data
of useful
in
one
facts,
library contains only data
sets that have been reviewed by a number of workers among whom there i consensus that they represent as good data as are available In the given class flow, and about which
reservations
known.
Only data
be
constructed
models
for
and
uncertainty
the
results
are included.
Data sets
sImulation
and
cover
for
checking
input to engineering procedures. bave
files by the
required
original
for individual computors During computational
the
work
trials
stated
information
the
data
are
insofar
as
that are sufficiently complete that a computational
sets
computer
in
also be used as
questions
of In
Department of Aero.
procurement
of
"data-takers."
output In
added
Data sets
that bears
"trial"
information this
can
Data
can
the completion of
and
complete
are
on both creating
from computation.
many instances,
they
clarification
would
of
thus be hard
to accumulate. establishing 1979
and
the
1980,
and Astro.,
a
library
and
considerable
writing amount
Stanford University,
57 -i
intended
"specifications"
was
Stanford,
learned
CA
%or
concerning
94305.
9tandardq
and
requirements
models or computational
for
data
trials.
intended
to be
These requirements
used
as
the
basts
for
have been incorporated
compurer
into guide-
lines for future additions to the library (see Section Vi below). .
The data library is current
collection
not viewed as "cast
that
will be
in concrete;
improved over time.
rather it
The
is intended as a
procedures
for
future
Im-
provements are also described below.
*
II.
HOW TO GET THE TAPE The data tape (hereafter
S."
"
referred
to as Library 1) will
be avail.ble
from one of
the following three locations: American users write to: AFOSR-STANFORD DATA LIBRARY c/o Brian Cantwell 371 Durand Building Stanford University Stanford, CA 94303 European users wriLe 1O
DFVLR c/o H. U. Meier Forschungsbereich Stromungsmechanik Bunsenstrasse 10, 3400 Gdttinpon, Germany Telephone (U5 51) 70 91; Te' 6 839
•g
Netherlands National Aerospace Laboratory c,-o .. F. J. Hicrema P. 0. Box 153 8300 AD Emmeloord, The Netherlands Telephone 05274-2828 Prices will vary from one agency to another and from time to time,
but in general the
cost should be less than S200.00. *•
III.
READING THE TAPE
-
Library
"
matted data.
I has been created by an IBM system 370 computer. The tape is
a 2400-ft,
9-track,
It
contains only for-
phase-encoded odd-parity,
written at a density of 1600 hits per inch according to EBCDIC code. mat is
fixed and blocked; record length
8000 bytes.
The
appropriate
job control
80 bytes;
=
statements
unlabeled tape The record for-
100 records per block; blocksize for reading the
tape using an IBM
system are: //GO.FT23FOOl ."
DISP
//
LABEL
DD UNi:T
T1600,
(OLD,KEEP),DCB =
-
VOL (RECFM
SER
= =
=
(LI3RARY
FB,I.REC
(1,\L)
58
.Oil
-
I),
80,BLKSIZE
8000,VDEN
3)
[ The
signates the
IV.
key
quantity
in
the above
control
the exact form of the data
DCB parameter,
see
statements
on the tape.
is
the DCH
parameter
which de-
For a more detaile'd d[scusoton of
1.
Appendix
FILE I Each
case
on
the
magnetic
File
1 contains a
*
more
files of norturlized
*
I1.
File I contains 1)
consists
detailed description of data.
A sample
11 sections
the
1980-81
or
more
ot
is
followed
This
File I for Case
namp
files
6631 is
information. by one or
Included as Appendix
follows. of
who originally
the author(s)
the flow case number and a brief descrip-
consistent with
title
two
the given case.
the
the data along with
tive
of
broken down as
This includes
Flow title: created
tape
AFOSR-RTTM-Stanford
flow class used
for the
the descriptor
Conference
on
Complex
in
Turbulent
Flows. 2)
'4
Revision ot File
3)
date:
This
.
The
""
the
most recent
revision
the evaluator who is
responsible
This
the apparatus
where
an approximate
item gives data
The
time when the measurements were actually
made.
information
is
set
Institution and, created.
this
the
the
was
to give the computor
the age of the data vis-a-vis measurement
an
capabilities of the
time. 5)
Abstract
of
periment
along
importance
6)
tion 7)
the experiment:
in
References: reference
8) '-
any
is
a
brief of
peculiarities
description of aork
the•
which
the ex-
may
be
of
Several references are usually included.
A-long with the
any re:erences
to instrumenta-
which contains the raw data,
techniques used are usually Included.
Instrumentati,,n:
Experimental important
A brief
constants
of
This
is
a
of
the
variables:
inferred
variables
listing
the experiment,
free stream velocity,
Measured
clature for data
description
methods
and
equipment
data.
parameters:
nel dimensions, 9)
with
This
deciding how to make use of the data.
used to take tie
*1
of
and date.
purpose of providing
"idea of
of
the data set to the 1980-81 conference.
location
possible,
date is
the date
The name and address
Experiment where
to
i.
Evaluator:
for recommending 4)
refers
This section
is
of the experiment.
found in
files
2 on.
59 -.1
S...............-'" .. "".i...i--..........-...-"........
of
numerical
values
including such things as Mach number,
a list
of all
The list
of
tun-
etc. of rhe measured
or
also serves as nomen-
-
10)
Measurement
uncertainty:
This
Is
uncertain-
a summcry of measurement
ties as provided by the evaluator. 11)
Is Lie key item
This
Tape organization:
In File
It
1.
contains
It
detailed defcription of all o0 the tape files for the given case. also contains write a file. is,
any
All data are in dimensionless,
variable
is
sionless variable are dete mined for
by
form.
the
That
appropriate
a power of the free stream
(for example,
and X
(Xma
Maximum and minimum values
velocity).
normalized
nondimensionalized
first
of the experiment
parameter
program which can be used to read and
sample
a short
a.
the given f tie.
to normalize cach data point, Xdimensionless,
th-
',f
dilmen-
These are used
us follows:
_- X Xdimensionless X X -a Xmi
Xnormalized
Xmax and Xmin are written in -E- formal
min
•"
as the first several records of the file are Each tape record
The remaining records at the head of the file. written as normalized data in the range 0 to 1.0. is written as a card image (hence record length To provide data compression and
parameter). number
of
variables
found useful
to
be
written
in many cases to
they were written onto
the
into an
integerize
tape.
In
80 bytes in the DCB
=
to permit 80-byte
the maximum
length,
it
was .
the normalized data before
these
cases,
Xnormalized was
multiplied by 10,000 and rounded up or down to the nearest integer to prcduce
IKnormalized.
ten onto tape data
were
20,000. the
as integers
written
as
In any case,
data
for
In these cases the norc
that
2.0
in
the range
or
in
the
from 0 to
particular
All null
integerized
case were normalized
data
as
and
integerized.
item 11 contains a description
of each file, including number of records,
V.
of
case
10,000.
item 11 contains a detailed description of how
In addition to the above information,
ture in item 9,
lized data were writ-
contents per the nomencla-
format (usually E13.6 or 16)
and comments.
NOM.'NCLATURE Although each case is
of each File i,
self-contained,
we have also tried, as
with its own nomenclature listed in
far as possible,
ture for all cases (see general nomenclature). of the nomenclature
found in
It
is
item 9
to retain a common nomencla-
essentially an extended version
Coles and Hirst.
D. E., and E. Hirst, Proceedings of the 1968 Coles, Conference on Computation of Turbulent Boundary Layers, Vol. It.
AFOSR-IFP-Stanford
60
-----------------------------------------------..................................................................-. .
,
VI.
tape
I!.
FLITURE ADDITIONS TO TIHE DATA LIBRARY Additions to Library I will conttnue will
be
submItted
library
will
library
for an
ued,
be
issued
to as
holdtng
appropriaite.
indefinite
the library
the
can be wish
noted
ful
(see
an
important
1) 1
additions
2)
for
Evaluat::!-
The
and of
this purpose
to the
which
editions
to coILI nue
1, 1982.
If
efforts
It
of
time the
to update can
the tape the
be contin-
to coompute
turbu-
a resr aisbiLity, for the library cannot evaluators throughout the tluld mechanizs
-he
flow
full
looking for common effects or
evaluation
reports will
aIjo
cor-
be use0-
and
library must meet conditions
similar
to those evolved
for
'ollows:
review by at
ieast
two experts
not associated with
the
taktng. r-sults
of
the
ment of the criteria 3)
are
at
in this volume).
conference as
data
Fature
part of world-wide
literature on a particular
Introductlon
Future
plans
1, 1981.,
may be called upon to asseSq thu suitability of new data sets. Here it that eventually the library will also be of -se to experimentalists who
in the data;
the 1980-81
organizations.
period of time beyond October
can become
to search the
relations
to November
Present
lent flows. It will be both a service continue without the gen.Žrcus efforts
"comm.unity who
,qp
data
evaluation
employed in
The data should be completely
should
selecting
documented,
include
an
explicit
state-
the data. including:
(a)
A complete
"(b)
A detailed uncertainty analysis. This should iclude a description of the method used, sufficient to make the analysis reproducible by a person knowledgeable in the state of the art.
(c)
A 3-
(d)
A suggested form for item 11 of File 1 (tape organization) which can be used to guide the tape processing operation.
(e)
Specification volume).
(f)
A complete list giving the values of reference lengths, velocities, and pressures used to normalize the data. All numbers should be exoressed in S1 units (kilogram/meter/ 2 second, pressure in pazcals N/M ).
(g)
A complete list giving mental variable.
list
to 5-page
of
references containing the data.
summary of the data suitable
of a
computational
the
trial
numerical
for publication.
(see exanplzs
range
in
this
for tach experi-
Ed. E The conditions for adding cases to tne Data Library are still under consideration and a final set of rules has not yet been established. Investigators wishing to submit data for consideration should write fur further information to Brian Cantwell at the address given on page 58.] 61
A.. .. .
. ..
--
41
(h)
A complete list of all variables used in the experiment, along with a Rpecification of the coordinates usqed. The nomenclature listed above should be used where possible.
(i)
A drawing of the experimental set-up would be very helpful.
Data
in
machine readable
However,
plots
submitted able
for
as a
and lists
VII.
index
lists
form are preferred can also
or plots,
published
be
they
volume
of
(rape,
cards,
accommodated.
should
be
provided
the meeting.
Axes
disc,
etc.).
If
the data
in
a
are
orm suit-
should be
labeled
should be headed usiiig the general nomeiclature.
index
to
the
lists
the
number of files is
lists
THE CONTENTS OF LIBRARY I An
The
and
tape
is
flow
-
included
cases
and relative
file
also included as the very
first
VIII.
at
the
numerically
end and
:f
this
gives
"olume
the
contents
1
numbers for each case
(pages
.n cols.
4-5.
of
624
to 632)
Library
I
by
."
A similar index
°*
on the tape.
file
ACKNOWLEDGMENT I
would
especially
like
the
Most of
the thanks
data.
Several
Carella. Schultz,
to express
students who
data
sets
Charles
always
educational;
before
they
could
to
the many
out
the
people who helped
difficult
task
of
create
processing
Library
were
by
Jim
McDaniel,
the data processing has been carried
Narty. they
processed
were
proceed.
While
sometimes
tedious
often
forced
seek
Without
their
to
energy
and
out and
and
of
the
and
Bob
on by Jim Taleghani,
Ken
Ranga
Jayaraman
frustrating,
the
reid original
enthusiasm,
thc
would not have been possible.
I
I,
data aets.
goes to Tony Straws ond Ram Subbarao who peocessed the bulh
More recently and
thanks carried
"
work was references
data
library "
6.
il
62
"'.
p.I
LA•
' :
--
- '•
.
== - ''
, '- - 'a " '- .•
.
' ..
."
"• ."-
.
" a."
APPENDIX I Rangara Jan Jayaraman
SIMPLIFIED GUIDE TO THE DCB PARAMETER RECFM,
LRECL and BLKSIZE subparameters of DCB parameters
The DCB parameter mers.
This is
ters
in
a brief
DCB.
"lengths"
in
a DD statement can be a source of confusion to many program-
and simplified
writeup on
For more detailed information,
in
in DD JCL statements
this writeup are in
REGFM,
LRECL,
and BLKSIZE
subparame-
consult IBM Fortran and JCL manuals.
All
units of bytes.
Input/Output Terminology Input/Output -
trolled
by a
(I/0)
is
FORMAT statement
associated with an I/O, transferr,-d
by
an
actual record." is
a
number
performed by READ/WRITE
I/0
then
it
a is
statement
"formatted
(>
1) of
Fortran
to form a meaningful
data
is
an "unformatted is
called
"data set
its
records
data
setata
randomly.
the
set is
grouped
If
there
I/O."
"I/0
is
list
An
reference
number."
set
is
Direct access
a
in
a
If
can only
I/O
list
of
through
then it
set" if
is
defines
an
blocks
grouped
referring to a
n-1 are to be ac-
a "sequential access
records in
reside on disks.
to be
A "block" of records
The number used in
data set,
"direct access data
data sets
of varl-bles
A number
records 1
An I/O con-
no FORMAT statement
The list
together.
a "data set."
cessed before record n can be accesse, data
I/O."
Fortran.
A FORMAT statement defines a "Fortran record."
together set
is
statements in
it
can be accessed
Data sets
on tapes are
necessarily sequential access data sets. RECFM The
"record
within it.
Data
0.
The
format"
the
data
aet
refers
to
the
physical
layout
of
records
possible record formats.
F
-
fixed length records
V
-
variable length records
FB
-
fixed length records
VB
-
variable length records grouped in
U
-
undefined
sets referred
gory.
of
following are a subset of all
grouped in
blocks blocks
(none of above)
to by unformatted
I/0 can only be under
the variable
length cate-
Direct access data sets can only be fixed and unblocked.
LRECL and BLKSIZE Associated length" 4
to
each
determined by the
responding lated
with
format
formatted I/0 list
statement.
the Fortran
record
I/0
statement
and "Fortran
are
two
lengths:
"actual
record length" determined
The
"1 'gical
record
length.
Lta
transfer
length" from/to
by the cor-
or LFECL paramete'r an I1.0 device
record
is
re-
takes place
63 •"%""
".
in so called
"'blocks"~ and
device/computer
the maximum
combination.
The
"block size" or
computer
comes
In
BLKSIZL
here
is dependent
because
in a segment of memory with the same size ac BLKSIZE; when it
firtt
transferred
as a block to the device.
in the computer memory.
data is
on
the
are written "full," it
is
Thus BLKSIZE is also the size of the "'buffer"
The parameter LRECL and BLKSIZE convey to the computor infor-
mation regarding Fortran record length Lnd buffer size.
The record format determines
what is specified and how. RECFM
V
LRECL
BLKSIZE
"not specified
waximum Fortran length LRECL +4
maximum Fo:Zran length +4
LRECL +4
F6
maximum Fortran length
VB
maxImum Fortran length +4
U
not specified
Notes:
. -
N*LRECL,
n='nteger > 1
4+n*LRECL, n-integer maximum Fortran length
The BLKSIZE chosen
in FB and VB should reflect
the compromise
tion of
number
accesses
the
reducing
core
of
available
for
I
to
the device
program use.
and
increase
Different
FORMAT
between in
reduc-
buffer size,
statements
with
po3libly different FORTRAN record lengths can refer to the same data set.
The
longest of the Fortran record lengths associated with a data set as its "maximum Fortran leugth". The physical organization of data in the device is as shown in Fig. data
are
separated
enable start/sto-s,
by so-called
"inter-block
is
transferred
various
cases.
DCB-(RECFM=FB,
to
provide
Blocks of
synchronization,
to
and to provide the required latency.
The actual record length can be less than, tran length.
gaps,"
1.
equal to or greater than maximum For-
The way actual data are written into the buffer and the way the buffer onto the device depends All LRECL-80,
data
on the record format.
processed
BLKSIZE-8000,
onto
DEN-3).
"64
t-pe
for
the
Fig. 2 illustrates the 1980
Conference
use
BLOCK of data
BLOCK of data
INTER- BLOCK GAP (IBG)
Figure ]
65
DEVICE STORAGE SPACE
I LK
RECFLM -
Logical Record
BD
Block Descriptor Word '4 bytes)
AR
-
Actual Record
SD
Segment D
B
-
Buffer or Block
LT
Blanks
IN CORE
F
---BI
-
-
B2 -
B3
'-"
-
-
B4
--
b"4
..
IN DEVICE
"Bi-
L K• •
i
-. UF-
AR3
AR.
IN CORE
RECFM - FB •
~LR1 -AR1 A-
.
B4
B3
B2
-
LR3
LR2
-4 LUFI
AR2
-
AR3
!-
.
LR4--•"'
=
-AR3--4
-
L-F
B
C
IN DEVICE
L• •
B
Figure 2 (cont.)
66 .
::: ::::::: ::::::::::::: :: ::::::::::::::::::: ••!:: :::::::
.
.
.'.-
!:
-. -
2 1 ...::*,
.
~i
. -
,
RECFM
IN CORE
-V
B34
B3
B2
Bl
IN DEVICE
__f~-
ILB GD
s
-
BI AR].
B2
-.
B3
-
k-
J
D Dý
AR3
"2
ODCj''
B-5 ARL
A12 B is
"I
AR3
considered "full" i.f
D
AR3
AR7W
UIF
:
UF < LIRECL
and next block is started
IN DEVICE BSI
RLECFM
B4
IN GOAE
VB
RECE'1
-
AR1
I S1
AR?.
AR3
IIAR3
'B
IN CORE
=U
B4
B3
B2
B].
IN DEVICE
AR] B
B
R2
BA
3
Figure 2 (end)
67
2..
B
4A3
APPENDIX II.
Sample File
1
1.
FLOW TITLE: CASE 8631; SETTLES, G. S., FITZPATRICK, T. J. AND BOGDONOFF, S. M.; "ATTACHED AND SEPARATED COMPRESSION CORNER FLOWFIELDS IN HIGH REYNOLDS NUMBER SUPERSONIC FLOW",
2.
REVISION
3.
EVALUATORS: RUBESIN, M. W. AND HORSTMAN, RESEARCH CENTER, MOFFETT FIELD, MOUNTAIN
4.
EXPERIMENT LOCATION AND DATE: CAMPUS, PRINCETON UNIVERSITY,
S5.
ABSTRACT OF EXPERIMENT: THESE RESULTS FOLLOW AN EXTENSIVE STUDY OF SHOCK WAVE / TURBULENT BOUNDARY LAYER INTERACTIONS AT TWO-DIMENSIONAL COMPRESSION CORNERS. THE CORNER MODELS WERE MOUNTED ON THE FLOOR OF THE PRINCETON UNIVERSITY 0.2 X 0.2 M HIGH REYNOLDS NUIBER SUPERSONIC BLOWDOWN WIND TUNNEL. TII TEST MACH NUMBLR WAS 2.8 TO 2.9, AND THE FREE-STREAM UNIT REYNOLDS NUM1BER WAS 6.3E+07/M. FLOWFIELD DATA ARE PRESENTED HERE FOR CCMPRESSSION CORNER ANGLES OF ALPHA=8 DEGREES (CASE A), 16 DEGREES (CASE B), 20 DEGREES (CASE C), AND 24 DEGREES (CASE D). CASE A IS A FULLV ATTACHED FLOW, WHILE CASE B IS NEAR INCIPIENT SEPARATION. CASES C AND D BOTH INVOLVE SEPARATED FLOW AT THE CORNER LOCATION. SURFACE AND FLOWFIELD MEASURErMENTS ARE GIVEN AT SELECTED STATIONS THROUGHOUT EACH INTERACTION. FINALLY, ADDITIONAL DATA SETS (CASES E-H) INCLUDE WALL PRESSURE MEASUREMENTS AND SEPARATION AND REATTACHMENT LOCATIONS FOR THE 20 DEGREES COMPRESSION CORNER OVER A REYNOLDS NUMBER RANGE, BASED ON INCOMING BOUNDA'RY LAYER THICKNESS, OF 0.8E+06 TO 7.6E+06. THE X COORDINATE IS DEFINED IN THE STREAMWISE DIRECTION ALONG THE SURFACE OF THE WIND TUNNEL WALL AND THE COMPRESSION RAMP. THE ORIGIN OF X IS AT THE COMPRESSION CORNER; THUS, ALL LOCATIONS UPSTREAM OF THE CORNER BEAR NEGATIVE X-VALUES, WHILE ALL THOSE ON THE RAMP BEAR POSITIVE VALUES. THE Y COORDINATE IS ZERO ON THE TEST SURFACE AND POSITIVE ABOVE IT, AND IS ORIENTED WITH RESPECT TO THE TEST SURFACE ACCORDING TO THE TABLE G:VEN BELOW.
DATE:
NOVEMBER
CASE A
18,
C
GREATER
Y ORIENTATION VERTICAL NORMAL TO VERTICAL
RAMP
SURFACE
NORMAL
RAMP
SURFACE
RAMP
SURFACE
RAMP
SURFACE
TO
VERTICAL NORMAL
M
TO
VERTICAL NORMAL
TO
REFERENCES: 1. SETTLES, G. TURBULENT BOUNDARY
S. "AN EXPERIMENTAL STUDY OF COMPRESSIBLE LAYER SEPARATION AT HIGH REYNOLDS NUMBER," 68
i
FORRESTAL
THAN
0.0127 M LESS THAN OR EQUAL. TO 0.0102 GREATER THAN 0.0102 M
D
C. C., NASA AMES VIEW, CA 94035
GAS DYNAMICS LABORATORY, PRINCETON, NJ 08544
X RANGE LESS THAN OR EQUAL TO 0.0254 M GREATER THAN 0.0254 M LESS THAN 0.0 M GREATER THAN OR EQUAL TO 0.0 M LESS THAN OR EQUAL TO 0.0127 M
B
6.
1980
.•i•"i. •- ?i- • i- '- / .•
-
.
..
-
•
- .-
•-.
..---
PH.D. DISSERTATION, AFROSPACE AND M1ECHANICAL SCIENCES DEPARTMENT, NJ, SEPTEMBER 1975. PRINCETON, PRINCETON UNIVERSITY, 2. SETTLES, G. S., BOGDONOFF, S. M. ANn VAS, I. E., "INCIPIENT SEPARATION OF A SUPERSONIC TURBULENT BOUNDARY 14, AIAA JOURNAL, VOL. LAYER AT HIGH REYNOLDS NUMBERS," JANUARY 1976, PP. 50-56. 3. SETTLES, G. S., VAS, I. E., AND BOGDONOFF, S. M., "DETAILS OF A SHOCK-SEPARATED TURBULENT BOUNDARY LAYER AT A COMPRESSION CORNER." AIAA JOURNAL, VOL. 14, DECEMBER 1976, PP. 1709-1715. 14 HORSTMAN, C. C., SETTLES, G. S., VAS, I. E-. BOGDONOFF, S. M. AND HUNG. C. M., "REYNOLDS NUMBER EFFECTS ON SHOCK-WAVE TURBULENT BOUNDARY LAYER INTERACTIONS," AIAA JOURNAL, VOL. 15, AUGUST 1977, PP. 1152-1158. 5. SETTLES, G S. , FITZPATRICK, T. J. AND BOGDONOFF, S. M., "DETAILED STUDY OF ATTACHED AND SEPARATED COMPRESSION CORNER FLOWFIELDS IN HIGH REYNOLDS NUMBER SUPERSONIC FLOW," AIAA JOURNAL, VOL. 17, JUNE 1979, PP. 579-585, 7.
INSTRUMENTATION: WALL STATIC PRESSURE DISTRTRUTTONS WERE SENSED THROUGH ORIFICES INSTALLED IN THE COMPRESSION CORNER MODELS. SKIN FRICTION WAS ESTIMATED BY PRESTON TUBE MEASUREMENTS. SEPARATION AND REATTACHMENT LOCNTIONS WERE FOUND FROM SURFACE STREAK METHODS AND WERE CONFIRMED BY THE OTHER MEASUREMENTS MEAN FLOW PROFILES WERE OBTAINED FROM SURVEYS OF PITOT PRESSURE, STATIC PRESSURE, AND TOTAL TEMPERATURE.
8.
EXPERIMENTAL PARAMETERS: IN ALL CASES THE INFINITY CONDITIONS ARE DEFINED IN TERMS OF BOUNDARY LAYER EDGE AT X=-0.5 M (THE INCOMING TURBULENT BOUNDARY LAYER AND FREE STREAM JUST BEFORE THE BEGINNING OF THE INTERACTION). FLOWFIELD PROFILES FOR CASES A-D ARE GIVEN BELOW. .1
,
TEST CONDITIONS XMINF ALPHA (DEG.) REINF/M TTOT (DEG. K) TW (DEG. K) TINF (DEG. K) UINF (M/S) (N/N**2) PINE
CASE A 2.87 8.0 6.3E+07 280 291 106 592 2,3E+O4
CASE B 2.85 16.0 6.3E+07 268 282 102 576 2.4E+04
CASE C 2.79 20.0 6. 3E+07 258 274 101 562 2.6E+014
CASE D 2.84 24.0 6.3E+07 262 276 100 569 2.4E+O4
COMMENTS MACH NUMBER CORNER ANGLE UNIT REYNOLDS TOTAL TEMP. WALL TEMP. STATIC TEMP. VELOCITY STATIC PRES.
DELINF
0,026
0.026
0.025
0.023
B.
(M)
L.
NO.
COMP. CORNER TO NOZZLE THF-.7;, •.
i.
FLOWFIELD
PROFILES
~CASES E-H."" TW(DEG. KM) 1..
.. .XMINF L ,ALPHA ". i.,TW
"r .
(UEG.) (M) R E NF /M TTOT (DEG. K) (DEG. K) L
ARE
ALSO
GIVEN
BELOW
28070-063
28
289P060.06
2. 95 21 0 .9.0 8 . 6 .3E+07 272 286
L .9 6 20 .0 . 98 . 3. 1E+08 268 28 1
2. 90 20. ?.0 3. 1 E+ 08 275 289
69
FOR
THE
[
THICK.
.f
ADDITIONAL
291CK
.
2.38820 . 98 .0. ... 3 .1IE+08 277 29 1
D
S.
FR
M
. "
"
3-
TINF (DEG. K) UINF (M/S) PINF (N/MI**2) DELINF (M) DELSINF (M) THETAINF (M) L.I (M)
99 58Q 2.1E+04 0.012 0.0033 0.0006 1.07
97 585 9.8E+04 0.011 0.0025 0.0004 1.07
103 589 1.1E+05 0.018 0.0046 0.0008 1.98
104 589 1.IE+D0 0.025 0.0061 0.0011 2.88
9.
MEASURED VARIABLES: X - STREAMIJISE COORDINATE (M) PW - WALL PRESSURE (N/M*42) CFINF - FRICTION COEFFICIENT BASED ON INFINITY CONDITION DENSITY AND VELOCITY XS - SEPARATION DISTANCE (M) XR - REATTACHMENT DISTANCE (M) Y - TRANSVERSE COORDINATE (M) XM - MACH NUMBER P - PRESSURE (N/M442) u i,.'AN S1;,..,,,ISE VELOCITY (M/S) REINF - REYNOLDS NUMBER BASED ON DELINF AND I'INF
10.
MEASUREMENT UNCERTAINTY: PW=+ OR - 2% CFINFý÷ OR 15% U=+ OR - 5% P=+ OR - 4% M=+ OR -3%/
S11.
TAPE ORGANIZATION: THE TAPE IS A 2400 FOOT, 9 TRACK, ODD PARITY. PHASE ENCODED, UNLABELLED TAPE WRITTEN AT A DENSITY OF 1600 BITS PER INCH ACCORDING TO EBCDIC CODE. THE RECORD FORMAT IS FIXED AND BLOCKED; RECORD LENGTH=80 BYTES; '00 RECORDS PER BLOCK; BLOCkSIZE=8000 BYTES. NORMALIZED DATA ARE CREATED FROM MEASURED DATA AS FOLLOWS: XNORM-(X-XMIN)/(XMAX-XMIN) NORMALIZED VALUES ARE INTEGERIZED BY MULTIPLYING BY 10000 "AND ROUNDING UP OR DOWN TO THE NEAREST INTEGER IXNORM:XNORM4 10000 THUS EACH NORMALIZED AND INTEGERIZED DATUM IS WRITTEN ONTO "TAPE AS A NUMbER BETWEEN 0 AND 10000. ALL NULL UATA ARE WRITTEN AS 20000. THE EQUATION DESCRIBING THE RELATION BETWEEN ACTUAL DATA AND THC NORMALIZED DATA ON TAPE IS X=XMIN+(((XMAX-XMIN)*IXNORM)/10000) WHERE X, XMAX AND XMIN ARE REAL AND IXNORM IS AN INTEGER.
FILE I
#
NREC
CnNTENTS TEXT FILE
FORMAT
X XPIW/PINF XPW/PINF X,PW/PINF
2E13 .6 2E13.6 216
X,PW/PINF
2E13.6
49
2
3.49
COMMENTS CONTAINS ITEMS 1-11 OF THIS WRITE-UP CASE A RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED VALUES CASE B RECORD 1 MAXIMUM
VALUES
70
=
=
•.'-
..
'4
X,PW/PIHF X, PW/PINF
2E13.6 216
X.PW/PINF X, PW/pINH X, PW/PINF
2E13.6 2E13. 6 215
CASE C RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED V A LVU ES"
X,PW/PINF X,PW/PINF ,X,PJ/P,,
2E13.6 2E13.6 216
CASE D RECORD 1 MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED VALUES
X,PW/PINF X,PW/PINF X, PW/PINF
2E13.6 2E13.6 216
CASE E RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VA!LUES RECORDS 3-49 NORMALIZED VALUES
X,PW/PINF X,P;/PINF X, PW/PINF
2E13.6 2E13.6 216
CASE F RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED VALUES
X,PW/PINF X,PW/PINF X, PW/PINF
2E13.6 2E13.6 216
CASE G RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED
'49
u9
6
49
./_49
8
49
RECORD 2 MINIMUM VALUEf2 RECORDS 3-49 NORMALIZED V A Lu ES
"VA.LUES 9
10
49 X,PW/PINF X,PW/PINF XPW/PINF
2E13.6 2E13.6 216
CASE H RECORD I MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-49 NORMALIZED VALUES
X,CFINF XCFINF
2E13.6 2E13.6 216
CASE A RECORD 1 MAXIMUM VALUES RECORD 2 MINIMiUM VALUES RECORDS 3-29 NORMALIZED VALUES
X,CFINF X,CFINF
2E13.6 2E13.6
X,CFINF
216
XCFINF X,CFINF XCFINF
2E13.6 2E13.6 216
X,CFINF
2E13.6
29
"X,CFINF
"Ii
12
13
21
23
20
71
CASE B RECORD 1 MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-21 NORMALIZED VALUES CASE C RECORD 1 MAXIMUM VALUES RECORD 2 MINIMUM VALUES RECORDS 3-23 NORMALIZED VALUES CASE D RECORD
1 MAXIMUM
VALUE:
14
15
X.CFINF X.CFXNF
2E13.6 216
XS.XR XS, XR XS, XR
2'E13.6 2E 13. 6 21T6
6
RECORD 2 ilIIIMUM VALUES RECORDS 3-20 NORMALIZED V AL U ES CASES C-H RECORD I MAXIMIUM VALUES RECORD 2 111NIMUN VALUES RECORDS 3-8 NORMALIZED V ALU ES uASE A STATION
'44 Y,XM. P/PINF, U/UTNF
1 l,X=-O.025'4
Mi
'4EI3.6
RECORD
I MAXtrUM
VALUES
U/UINF
'4E13.6
RECORD
2 MINIMUM
VALUES
U/UINF
'416
RFCORD VAiLU ES
3-44
YXI, P/PINF,
16
CASE A STATioN
41 Y X MI,P/P I N F, U/UINF Y.XI. P/PINF, U/UI1F Y,XI, P/PINF, U/UINF
17
NORMALIZED
MI
2'4,X=0.0
VALUES`
4E 13. 6
RECORD
1 MAXIMUM
'4E13.6
RECORD
2 MINIMUM VALUES
'416
RECORD VALUES
3-41
CASE A STATION
35
NORMALIZED
29,X=0.0025
11
Y, XM, P/PI NF, U/UINF Y .Xl, P/P INF, U/UINF Y , Xi,P/P INT. U/UIHF
18
RECORD
I MAXIMUM
VALUES
'4E13 .6
RECORD
2 MINIMUM
VALUES
416
RECORD VALU ES
3-35
CASZ A STATION
40 Y,XM. P/PINT, U/UINF Y,XM, P/PINT. U/UINF Y .XM, P/PINF. U/UINF
19
4 E 13 .6
"l
VALUES
RECORD
2 MINIMUM
VALUES
RECORD VALUES
3-40
RECORDI)
4 E13 .6 '41G
CASE A STATION YXM. P/P IXF, U/UINF PIP INT Y ,XM U/UINF
31,X=0.0051 MAXIMUN1
4E13.6
41
NORMALIZED
N~ORMALIZED
33,X=0.0i02
11
4E13.6
RECORD
1 MAXIMUM
VALUES
'4E13.6
RECORD
2 MINIMUM
VALUES
'416
RECORD
3- 4 1.
Y ,Xi, P/PINTF. U U IN r
VALU ES
72
- ANI. Z L:ZE)
I. 20
34
~Y.X'M'P/PINFI
•
U U/UINF . ,X,.,P/P:NF, U/UINF YX , P/P IrF, U/UINF
21
23
25
•
VALUES
4 E13,6
RECORD
2
VALUES
416
RECORD V A LU ES
3-34
NORMALIZED
M
4E13.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-3S
MINIMUM
NORMALIZED
52,X=0.0663
M
Y,XM,P/PINF, U/UIF
4E13 .6
RECORD
I MAXIMUM
VALUES
YXM, P/PINF, U/UINF
4E13.6
RECORD
2
VALUES
Y,XM,P/PINF, U/UINF
416
RECORD VALUES
3-41
40
CASE A STATION
NORMALIZED
69,X=0.1372
M
RECORD
I
MAXIMUM
4E13.6
RECORD
2
MINIMUM VALUES
416
RECORD VA LU ES
3-40
41
CASE B STATICN
VALUES
NORMALIZED
5,X=-0.0381
M
4Z13.6
RECORD
1 MAXIMUM
VALUES
4E13.6
RECORD
2 MINIMUM
VALUES
416
RECORD V'ALUES
3-41
41
CASE B STATION Y ,XIP/PINF, U/UINF Y, XM P/PINF, U/UINF Y.XM, P/PINF, U/UINF
MINIMUM
4E13.6
NORMALIZED
17,X=-0.0127
M
4E13.6
RECORD
I
MAXIMUM
VALUES
4E13.6
RECORD
2
MINIMUM
VALUES
416
RECORD V, L LU ES
3-41
73
-- 9 .
MINIMUM
47,X=O.Oq57
CASE A STATION
Y,XM, P/PINF, U/UINF Y,XMP/PINF, U/UIHF Y,XM, P/PINF, U/UINF
-
I MAXIriUM
41
.Y.XM,P/PINF, U/UINF Y,XM, P/PINF, U/UINF YY,XM,P/PINF, U/UINF
24
M
RECORD
CASE A STATION
SU/UINF 22
39,X=O .0254
4E13.6
35 - .Y,X N, P/PINF. U/UINF Y,XM,P/PINF, U/UINF Y,XMP/PINF,
"A'
cAs: A STATION
NORMALIZED
"m 26
Y,XM,P/PINF, U/UINF Y,XMP/PINF, U/UtINF Y,XM,P/PINF, U/UINF
27
VALUES
4EI3.6
RECORD
2
VALUES
416
RECORD VALUES
3-41
MINIMUM
M0G
NORMALIZED
33,X=0.0
r" -
RECORD
I MAXIMUM
VALUES
4613.6
RECORD
2 MINIMUM
VALUES
416
RECORD VALUES
3-142
NORMALIZED
N_
41.XzO.5OO
4E13.6
RECORD
1 MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-42
CASE B STATION
MINIMUM
NORMALIZED
53,X=0.
191
M
4E13.6
RECORD
1 MAXIMUM
VALUES
4E13.6
RECORD
2 MINIMUM
VALUES
416
RECORD V A LU ES
3-q1
a
.'.
CASE B STATION
38
NORMALIZED
61.X=0.0381
M
4EI3.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-38
CASE
44
MINIMUM
NORNALIZED
B
"STATION Y,XM,P/PINF, U/UINF Y',XM. P/PINF, U/UINF
0
4E13. 6
41
Y,XM,P /PINF, "UUINF
0i
1 MAXIMUM
CASE B STATION
Y, XM, P/?IHF. U/UINF Y XM, P/P INF, UIUUIHF Y,Xi-iP/PINF, U/UINF
31
RECORD
42
Y,XM,P/PINF, U,'UINF YXIMP/PINF, U/UINF Y,XM,P/PINF, U/UINF
30
4EI3.6
CASE B STATION
Y,XM,P/PINF, U/UINF Y,XM,P/PINF, U/UINF Y, M,P/PINF, U/UINF
29
25,X:=-0
42 YXMP/WIN , U/UINF Y,XMP/PINF, U/UINF Y,XMP/PINF, U/UINF
28
CASE B STATION
41
73,X=0.0762
M
4E13.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2 MININUM
'VALIE-S
416
RPECO.RD VALUES
3-qt
74
NOP21ALIZE`
32
45
CASE B STATION Y'XM,P/PINF, U/UI(F Y,XM.P/PINF. U/UINF
1 MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
RECORD VA LU ES
3-45
CASE
14,X=-O.0381
M
4E13.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
Y,XM, P/PINF, U/UINF
416
RECORD VA L UES E
3-q0
47
CASE C STATION
36,X:-0.0111
m"
1 MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-47
MINIMUM
NORMALIZED
C
STATION
50,X=0.0
4E13.6
RECORD
1 MAXIMUM
VALUFS
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-37
30
CASE C STATION
"U/UINF
NORMALIZED
RECORD
CASE
Y ,XM,P/PINr-, U/UINF YiXM.P/PINF, U/UINF Y,XM,P/PINF,
MINIMUM
UEI3.6
37 Y,XMP/PINF, U/UINF Y,XM, P/PINF, U/UINF YXM,P/PINF, U/UINF
36
NýRMALIZED
YXMP/PINF, U/UINF
Y,XM.P/PINF, U/UINF Y °XM, P/P 'tF, U/UINF Y, X ,P/PINF, U/UINF
35
MINIMUM
C
STATION
34
Mr
RECORD
40
YXMP/PINF,. U/UINF
1397
LIE13.6
7,XM,P/PINNF , U UINFf416 33
83,X=0.
MINIMUM
M
NORMALIZED
55,X=O.0O04
M
4E13.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2 MINIMUM
VALUES
RECORD
3-30
416
NORMALIZED
"VALUES 37
25
CASE C STATION Y,XM,P/PINF, U/UINF Y,XM,P/PINF, U/UINF Y,XM ,P/PINF, U/UINF
M
4EI3.6
RECORD
I MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
q16
RECORD VALUES
3-25
75
..
66,X=0.0127
S...
MINIMUM
NORMALIZED
I,.
V= 38
CASE C STATION
39 Y,XMP/PINF, U/UINF Y,XM,P/PINF, U/UINF Y,XM,P/PIN , U/UINF
39
70,Xý0.0254
M
4E13.6
RECORD
1 MAXIMUM
VALUES
4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-39
MINIMUM
-F
CASE C STATION
38
NORMALIZED
.5,XX0.0413
M
Y. XM, P/PINF, U/UINF Y,XMIP/PINF, U/UINF Y,X1.X ,P/PINF, U/UiNF
40
I
MAXIMUM
VALUES
iE13.6
RECORD
2 MINIMUM
VALUES
416
RECORD VALUES
3-38
NORMALIZED
86.X=0.0762
f.
4E13.6
RECORD
I MAXINUN
VALUES
'4E1 .6
RECORD
2 MINIMUM
VALUES
416
RECORD VALUES
3-41
CASE C STATION
47
N
,iAXIMU.1 VALUES
RECORD
I
U/UINF YXM,- P/ P I MF,-
4E13.6
RECORD
2
U/UINF
416
RECORD VALUEE
3-47
MINIMUM
VAF.UES
NORhALIZEb
2,X=-0.0635
M
4F13.6
RECORD
1 MAXIMUM
VALUES
6
RECURD
2
VALUES
RECORD VALUES
3-49
4E13
..- -
-
CASE 1) STATION
119
IL..
NORMALIZED
94,X=0.1143
4E13.u
Y,XM,P/PINF, U/UINF Y,XM, P/PINF, :;/UINF
-
:.
CASE C STATION
Y.XM,P/PINF. U/UINF Y,XM, P, " INF,
42
RECORD
41 Y,XN, '/PINF, U/UINF YXM, P/PINF, U/UINF Y, Xl,P/PINT, U/UINF
4 1
4E13.6
MINIMUM
Y,XM, P/PINT,
U/UINF
43
'416
CASE
48
D 10,X -C.O0305
STATION Y,XM,P/PINF, U/UIN F Y ,X.M, P/PIN , U/UiNF Y,Xi,.P/PIN ,; U/UINF
NOMI,:ALIZED
4E13
6
RECORD
1 MAXIMUM
qE13
6
RECORD
2
REEC 0 V AL U ES
3-ti8
416
""76
VALUES
'1IN:rJUPI VALUES NO4RMALIZED
"
F44 41
CASE D
Y.XM, pip I F, U/UINF / XI
i4E13.G
IiNPF,4
3
U/IF4G
145
48
M
RECORD
1 MAXIMUM
VALUES
4E13.6
RECOiD
2 MINIMUM
VALUES
416
RECORD V ALU ES
3-48 NORMALIZED
CASE D STATION
26,X=0.0102 M
4 E 13 .6
RECORD
1 MAXIMUM
VALUES
'4E13.6
RECORD
2 MINIMUM
VALUES
416
RECORD) 3-39 VALUES
46CASE
D STATION Y ,XII, P/ P INF, U/U I NF Y ,XM, P/P I F, U/UINF Y ,XM, P/PINfl, U/UINF
NORMALIZED
33,X=0.0305
RECORD
1 MAXIMUM
VALUES
4 E 13 .6
RECORD
2 MINIMUM
VALUES
416
RECORD V A LU ES
3-46
NORMALIZED
CASE D STATION~ 39,X=0.0610
M
4E13.6
RECORD
1 MAXIMUN
VALUES
4 E 13.6
RECORD
2 MINIMUM
VALUES
416
RECORD 3-47 V A LU E:S
47
CASE D STATION Y.XM, P/PINF, U/UINF Y.XM,P/PINF, U/UINF Y,XII1,P/PINF, U/UINF
M
4 E 13 .6
47 Y, XI, P/P INF, U/UINF Y.XM, P/PINF. U/JINF Y,XM, P/PINF, U/UINF
*49
2,,=.
4 E 13 .6
39 Y ,X M, P'PIN F, L -J I NF Y,XM. P/PINF, U/UlI NF Y ,XI, P/PINF, U/U IN F
48
NORMALIZED
Xr,P/P I F,
!J/UINF y X, XI, P/ PINm F U/U I NF
47
VALUES
EOD2MNMMVLE
CASE D STATION
Y,
1 MIAXIMUMI
RECORD 3-u1 VA LU E.S
Y.XI, P.' PIN F, U /U INF
46
RECORD
NOnMAL.IZED
47,:<=0.1016
4E13.6
RECORD
I MAXIMUM
VALUES
4 E 13 .6
RECORD
2 MINIMUM
VALUJES
416
RECORD VALUES
3-47
77
N4ORMALIZED
-
50
CASE D STATION
48 Y,XM,
P/PINF,
U/UINF Y,XM,P/PINF, U/UINF Y,XM,P/PINF, U/UINF
55,X=0.
1422
M
4 E13.6
RECORD
I MAXIMUM
VALUES
t4E13.6
RECORD
2
VALUES
416
RECORD VALUES
3-48
MINIMUM
NORMALIZED
A SAMPLE PROGRAM FOR READING AND PRINTING FILE 2 IS THE JCL IS FOR THE THE STANFORD CIT FACILITY. SHOWN BELOW. CHECK WITH YOUR OWN COMPUTER FACILITY FOR THE EXACT JCL NEEDEL. SETTLES JOB //TAPE TAPE1,ItIPUT=(LIBRARY NUMBER ASSIGNED TO TAPE) /*SETUP 1/ EXEC FORTCG DD * //FORT.SYSIN READ FILE 2 OFF THE TAPE AND PRINT THE MAXIMAS AND C MINIMAS OF ALL THE VARIABLES AS WELL AS THE NORMALIZED C C AND INTEGERIZED VALUES OF ALL THE VARIABLES INTEGER X(47). PW(47) XMXPW'IX READ(23,30) XMNPWMN READ(23,30) C SET N=THE NUMBER OF RECORDS IN THE FILE MINUS 2 N=49-2 DO 10 I=,NI X( I ,PW(I) READ(23,40) 10 XMX,PWMX WRITE(6,50) WRITE(6,50)
*
XMN,PWMN
DO 20 I-1,N X(I),PW(I) WRITE(6,6O) FO RIAT(2E13.6) FORMAT(216) FORMAT(1X,2E13.6) FORMAT(1X,216) STOP END DD UNIT=TI600.VOL=SER=(TAPE,LIBRARY), //GO.FT23FOOI // DISP=(OLD,KEEP),DCP=(RECFMl=FB,LREC=80,BLKSIZE=8000, /1 DEN=3),LABEL=(2,NL) //7 20 30 40 50 60
-L.
.
78
.
.
.
.
.
DISCUSSION The Data Library
P.
What code was on the tape,
Bradshaw (Imperial College):
B. Cantwell:
P.E. or N.R.Z?
Phese encoded--P.E. (Stanford University):
W. C. Reynolds
as all these computors start work-
Inevitably,
Ing with these data there will he things found that need to be fixed.
What pro-
visions are made for disseminating this information? of tape users will be kept and updated information will be mailed
A list
B. Cantwell:
out to all users as errata. S.
J.
At
Kline:
the
end of
the
1980 meeting various
to assume one flow and compute it
asked
computational
very early to see if
up to prevent other groups having similar problems.
groups will be
some troubles
show
This ha3 been done.]
[Ed.:
Please indicate where these tapes will be
G. Sovcan (General Motors Research Labs.): stored. Initially
B. Cantwell:
all mail ings
to computors will be from Stanford.
Later the
tapes will be available from three sources listed on page 58 (this volume].
"G.Mellor
There will be about six months between the availability of the (Princeton): data tapes and the deadline for submission of predictions, which is a very short period of time.
The end result will suffer because of this short
The first tape will become available
B. Cantwell:
on November 30,
version with a few more cases will come out on January 31,
time period.
1980.
1981.
An updated
In the meantime
the test cases are also availablo in the literature.
*S.
J.
Kline:
this time period
If
is
too short,
we shall discuss postponing the 1981
meeting.
-.
"W.C. Reynolds:
Will the 1968 Conference flows be included?
We have included three cases and hope to incluee more later.
B. Cantwell:
Are there any others who feel that the timE period
V. C. Patel (University of Iowa): allowed for computation is
too short?
(About half a dozen thought so.) Let
G. Sovran:
this be one of the topics
for discussion
in the open forum in
Ses-
sion XIV. At the evening discussion B. Cantwell, *
.
L
the
criteria
for selection of
classes of flows were omitted. flows
to be added
to the data
types of It
R.
flows.
V. C. Patel and J.
So, It
was
Hunt discussed
that certain
felt
important
was further felt that a discussion of the types of the open forum in
library should be discussed in
Sea-
sion XIV.
79
. •.
.-.
.
... .
-..
.
.
-..........
.........
SESSION I
Chairman:
V. C. Patel
Technical Recorders: R. Subbarao P. Parikh
Flow 0610 Flow 0210 Flow 0230
81
-0~
.
.t
ATTrACHED BOUNDARY LAYERSJ Flow 0610 Cases 0611, 0612, 0613 Evaluator:
D. E. Coles*A
SIUhOARY
Certain test cases were selected from the 1968 Conference. Case 0611.
Attached Boundary Layer (Tillman, Ledge Flow)
Case 0612.
Attached Boundary Layer (Wieghardt, Flat Plate Flow)
Case 0613.
Attached Boundary Layer (Bradshaw
a
-
These were:
-0.255)
However, after discussion at the 1980 meeting, only Case 0612 was selected as a a
~
test case for 1:.e 1981 meeting.
011
-A
~*California
Institute of Technology, Pasadena, CA 82
91125
SPECIFICATIONS
FOR COMPUTAT71ON
SIMPLE CASE/INCOMPRESSIBLE
Data Taker:
Floei 0LO.
K.
E. Coles
D.
Data Evaluator:
Case 00612;
Wieghardt
PLCTORIAL U0.Y Atte-had Ioon4.ry Layer.
Deta Kvehl tori 0. 1. CoLes.
Ceo
gote, T.".r
Test Rlg
or
G.~t.lr
CP
U
/tTy
yurbulone
C-ofen.o...
1
Pro
C
or Ii
Otiar
-j,
Other
i
Ce
I2.2
Usos 04.12
K.
('61
oue
shwaosr.f Irotloac-
Ve 1
(1968)
0
"oghret
i3
106
y
*
Irb1....
Data too Lde -P~ot.d . Lua of booundry
1,,4 -
.. layer Lntlerel ptrea ters.
_
__________-i-I--__-_
Plot
Ordinate
Abscissa
Range/Position
1
y
U/Ue
x - 4.987 m
2
Cf
x
0.087 < x < 4.987 mu
3
H
x
0.087 < x < 4.987 m
Special Instructions,
Comments One profile only.
General Comments: L
This
is
a check
flow to
tie
to 1968
results,
and assure
simple shear layers are
modeled adequately. Starting conditions can be laminar or turbulent.
83
83"
Please report what
is
used.
PLOT 1 CASE 0612 FILE 25 0.08
-
0.06
y 0.04 0 0
0.02
0 0 0 0
0.004
o00
0
0.25
0.5
0.75
PLOT 2 CASE 0612 FILE 2 0.008 0
0.004
o
CF
o
CYLT
0
Cf
00
0.002
.4 01
0.000
-4 I...
0
t
I
2
3
84m) I
84
C.-
5
PLOT 3 CASE 0612 FILE 2
2.5-
2.0
1.5
~
'
c
'
c
7
0.
-
0
1
2
345 x (in)
85
EFFECT OF FREE-STREAM TURBULENCE ON BOUNDARY LAYERS Flow 0210 Case 0211 Evaluator:
P.
Bradshaw
SUMMARY
SELECTION CRITERIA AND FLOWS SELECTED This
report
(1980).
Since
is
based
previous
unsatisfactory,
coefficient
length
of
the
data,
the available
skin-friction scale
on
in
Ph.D.
thesis
reviewed
by
of
the
iancock,
evaluator's
are
student,
incomplete
or
in
Hancock
some
ways
data are presented as a correlation for the variation constant-pressure
free-stream
turbulence,
boundary
based
on
layers with the
Hancock's
results
of
intensity and
and
on
previous
work. It
is
intuitively
stream turbulence is
obvicus,
and
also
seems
to be
true,
that
the effect
of
felt mainly by the outer layer of the boundary layer.
free-
.
Although
some investigators have just assumed without discussion that the logarithmic law still applies
in
friction
its
usual
values
well
with
high
turbulence
Also,
pressure
layers
in
ze'o
ent,
from
in
logarithmic
are
and
the
gradients
do
outer not
able
to
pressure
gradient
has led law or
predict
be
still
influence
effects
so that
it
turbulcnce effects
Alas,
the
point
that is
gradient
almost
regions. and on
in
in
all
known
to be slightly
investigators
component
being about
from
grid
tha
for
the
cross-sectional
plane,
intensity
and
(say)
Imperial College,
1.2
but
boundary
an academic
have
used biplane
consistently
times
to
scale.
Prince Consort
Road,
have
become
pres-
pressure
London,
where
SW7
2BY,
turbulence
longitudinal
At
which
is
mean-square
large enough distances
approximately
specified
cases
grid
(the
components).
can be In
square-mesh
anisotropic
the lateral
turbulence
one length
layers
one at
importance of pressure gradients.
turbulence the
simple
boundary
because most of the experimental dita refer to boundary layers without
Nearly
most
that a physically
adequate
satisfactorily is
agree
layers with
log-law
follows
(skin-
to
directly,
pressure
probably
seem
Boundary
structure of
results
reading
recognizsble
turbulence
the
tube
accepted.
have
will also perform
pressure gradient.
to self-consistent
i'reston
therefore
layer
for free-stream
gradients despite the practical
well
can
with adequate accuracy,
allowance
with arbitrary
this assumption
checks)
level
methods
well-founded layers
deduced
independent
calculation boundary
form,
by the
homogeneous
longitudinal
free-stream
in
the
component
t¶,rhulence
spectra
England.
86
***
*
.
*-.
.
".
I..
decay
the
of
rate
ments
have
series
of
been
of ordered
unsteadiness,
and
machine,
that
the
u- "/2
ter fl with
but
probably
the
""
This
U,6/v. used,
orate
fit
cubic
sents
the
shape
is
not
with
linearly
for the
effect
on surface
that its
apparent Ue,
not
the
the wake parame-
If
It
is
(1974)
at
e
given
commonly
is
shear stress
that
fact
in
wake shape
in
is
of the extrapolated
terms
in
of change
scale,
velocity
correct
the
is
found
tu
2
I"
incompatibility with the inner and
implicitly defined
r, is
enter.
to
due
Finley
free-stream
high
skin-friction
of
et
due to free-
turbulence of
a
function
friction at the same momeLtum-thickness boundary
constant-pressure
laye," without
practice
the dependence on 1ke, that should enter this equation is
cous effects
in
than
the upper Thus
the outer layer.
limit
Cf/Cfo
-
of
',ue"
ueij/
free-stream
in
numbers greater
of
2
about
5000
/e,
L/6)
and of
/L:e
(for conve-
Reynolds numbe,
nence)
for Reynolds
the wake profile
free-stream-turbulence
correlating as
coefficient
Since
intensity.
repre-
adequately
turbulence.
In
at least
negligible,
for significant as shown in
Fig.
visI.
87
.. .•
-'t'q'_-•:•
.
:-. - -,• .•- .': .
"
snape
wake-profile
the
1963)
Moses,
(see
al.
the simplest way
to define, terms
a
in
a variation
as
of
and that neither the traditional cosine curve nor the more elab-
at
difficult in
intensity
L/6""
and considerations
,
originally
L/6 times the skin ---.
need
profiles
is
effects
-
6
considerably,
changes *
y
at
turbulence
stream
the
It does
turbulence.
similarity analysis suggests that
varies
U.,
which
in
the above analysis
velocity
log-law
to observe
analysis,
in
spurious.
correlation
of
useful
is
layer
outer
"
torm
it
and
of
rotation
moderate
by
unaltered
1/2 /U, f• %U '-
coefficient
skin-friction
the
that
of
speed
the
partly
of the free-stream turbulence. streamwise length scale (Le) 1/2-l/2 Bradshaw e, a few lines of algebra given by iA/2/Ue," /'J* with (uz
the
-
thu form
in
linearly
changes show
is
L
far
effects
its
conslits
"turbulence"
anisotropic,
be correlated
can
il where
is
law
logarthmic
turbulence
of free-stream
effect
to
related
the usual wall-plus-wt.ke
turbulence,
free-3tream
The
frequencies random,
truly
bar grids;
A few measurements of free-stream
made.
been
the
to synthetize any test cases from the turbomachinery data.
not seem reasonable Providing
with
of
partly
also
have
turbomachinery
in
parallel
the
is
example
One
be
of measure-
fairly close in
this case seems to be
in
therefore
A few sets
behind
(1972)
square mesh grids.
by conventional
turbulence
al.
et
is
turbulence.
free-stream
Huffman
by
turbulence
the
of
kinds
can
avallable,
latter
cases.
all
between
comparison
other made
measurements
to that produced
"
in
made
downstream,
eniough
of
basis
straightforward
most
the
and
parameter,
length
where
scales,
length
Other
turbulence.
the
from
length parameter
Lhe dissipation
to deduc,
possible
is
simple dissipation
to this
related *
it
not been measured,
have
.-. '.
.
.
.- .
.
.
. -2.
.-..... - -
.
". ."--
..
..-
.-
.i
-"
"
"
-'
....
. "
.
ADVICE FOR FUTURE DATA TAKERS The assumption one
velocity
that
scale,
inherent
equivalent
to
turbulence
should be
to
use
more
anisotropic work
is
and its
current
to
leading
homogeneous
previous
and
are
at
the
the i e1 i
the
as
(x
edge.
X0 /M must time
the of
it
the
(i)
it
is
edge
to avoid
it
the
in
arbitrarily
use,
axial
is
he necessary
with
practical
it
free-stream
should not
field
more
but
turbomachines
constraint
Since the
and
(2)
calculation the
spurious, residual
layer,
provides profiles
of
turbulence
measuring
since
6
is is
station,
in
to
grows
the outer
in
adequately
must
Reynolds
faster than
be
far
number Re5
layer.
These
L,
it
both
L/6 and
for intensity and length scale to
is
IP v
very difficult
from previous data.
some difficulty
be
which
published dota exceut Hq!ec'-' Thus
the position of
intensities of much more than 0.05
The tendency
a are
turbulence
covering
while
the
trajectory settling
in
intensity length Fig.
down
I;
from
a
,,
close to
to extract
in-
Even after recognizing
reasonable
area
in
the
ia-
length
scale
just
the
initial
as
assumed
inevitably
increases,
portion
the calculation
starting
The correlation
scale may appear
should be done with more values of L/i
inevitably decreases with the distance
the
and probably' easily seen to be so. effect
xo
The boundary-
plane.
the free-stream boundary
the
where
the momentum-thickness
'e, len e-- L/d plane.
Hancock had
if
to achieve rms
so strong that all
tensity/length-scale
5
first
for
increasing x.
sigl
approximately.
severe viscous effects
difficult
station,
about the
formatian about the effect of length scale
a
disturbance
however,
although
of
approximately,
exceed
leading
is
decrease with
vary together
(where
be
L varies as x
xo/,
-
reaches
2000 so as
at any measuring
iown
crude;
Experiments
to
length 3cale ald
effect of free-stream length scale or spectra is varies with distance x from the grid as x-,12
length scale
6 varies
that,
(uý)i/2/Ue
of
by
about
facts mean
this
present. likely
is
and
the experiment
not
classify
work,
assumptions, in
correlations
turbulence
explore
while
downstream
to exceed
Ue
data
exploration
thickness
enough
all
by one
effect on blade and annulus boundary layers.
approximately,
the
nearly
be characterized
turbulence-modeling
free-stream
needed
in
can
carefully documented
elaborate
Further
layer
grid turbulence
in
in
the calculations,
of
condition) Fig.
I is
in
each
will
be
empirical;
which case
runs
to document effect.
-
88
F
_ • ... . . .
•. " .
..
..
.L
.,.
REFERENCES (1974). Bradshaw, P., Report 74-10, Dept. Charnay, G., boundary No. 93.
"ECfect of free-stream turbulence on turbulent of Aeronaut., Imperial College, London.
and G. Comte-Bellot, layer on a flat plate
shear
layers,"
"Development of a turbulent J. Mat'ieu (1971). in an external turbulent flow," AGARD Conf. Proc.
"A single formula for the complete velocity Dean, R. B. (1916). lent boundary layer," j. Fluids Engr., 98, 723.
profile in
a
turbu-
R. L. (1972). "Free stream turbulence effects on the turbulent boundary Evans, layer," Dept. of Engineering, University of Cambridge, Report CUED/A Turbo/TR41. Finley, P. J., K. C. Phoe, and C. J. Poh (1966). turbulent water layer," Houille Blanche, 21, 713. "On the (1972). layer as it relates nical Report 72201.
Green,
J.
F.
"boundary
"Velocity measurements
influence of free stream turbulence on a to wind tunnel testing at subsonic speeds,"
in
a thin
turbulent RAE Tech-
"The effect of free-stream turbulence on turbulent boundary P. E. (1980). o.Hancock, Available on microfiche from Imperial College, Lonaun. layers," Ph.D. thesis, Dept. of Aeronaut., Imperial College, London, SW7 2BY. D. R. Zimmerman, and V. A. Bennett (1972). Huffman, C. D., turbulence level on turbulent boundary-layrr behavior," "The response of Meider, H. U. (1976). levels In the external free stream," Kreplin H. U., and H. P. Meier, boundary-layer development," J. Moses,
H.
(1963).
"Gas
"The effect of free-stream AGA&D Conf. Proc., 164.
turbulent boundary layers to small DFVLR Report !B 251-76 A.17.
(1980). AIAA, 18,
turbine lab report,"
"Influence ii.
of
Massachusetts
free-stream
'z-
89
turbulence
on
Institute of Technology.
"Stream turbulence Robertson, J. M., and C. F. Holt (1972). boundary layer," Proc. ASCE, 98, LO'03.
r•
turbulence
effects on
the turbulent
,
-Preferred -
curve
0-2
ACfO r/-7
7
C~ 0 0.10
0
X
1.0
2.0
U
V e
.
2.0'J ---40/-
/.995
Hancock (1980) and H~olt (1972) S Meier (1976) corrected using ~ Evan (1972 Meier's results S Huffman et al. (preferred) Green's analysis of Hu&-fman et al. till AnalyAis of Huffmnan et al. following Green '~\Charnay et al. (1971)---Bradshaw's (1974) analysis employed
~I Robertson
Figure 1.
Correlation of -)Cf/Cfo, where C-f 0 is value with U 90
41I
0 and same Re,
DISCUSSION Flow 0210 J.
Hunt:
I have two points to make: In
1.
Is
fects of
the
quantities
"oF
the only important
In
If
layer. is
your
is
the
I
of
the
length
large
for
turbulence
5,
presence
of
in
to
There
the turbulence the wall
the normal
for
think it
are
and
.t is
Bradshaw:
layer
S.
aýway
So
Morkovin:
of
the
interaction
and
5.
layer will be atfec-
outer damped
to make
iX would
region where
be a
ar.ificial
point wh-
the turbu-
of the wall. more
tur'bulence,
from the
1, 2,
ini-
if
detailed it
comparisons
has a large
scale,
The conditions to be speci-
edge of 1-
the boundary layer.
I
is
to
whal
rather is
between
lar6,.
eddies
of
free-stream
will fall
out
far away from the wall.
unlikely,
happening
of free-stream
Free-st eam a
plate.
-
a revised specification for
in
the law of the walt change due to the
in
because
the law of
the outer part
turbulence.
I
of
cannot
the wall
is
incred-
an ordinary boul,dary imagine the
constants
any of the cases we have chosen.
alongside
Li'
S................"
farther
that the constants
turbulence
upstream of
Data should
a plate ma,, be
different
therefore also include turbulence
from
intensity
the stream approaching the plate. Could you say to what extent
'' ion effects as opposed
.'
measurements
The fre2-stream
are
this
the absence
as a scale in M. V.
reduced.
be
the
the free-stream turbulence.
insensitive in
one
within the
suggest
the boundary layer &nd the boundary layer itself
possible
Klebanof f: data
have an
feeling the presence
carried to a point
I think
changing in P.
you will
y.-u
:;hould
the boundary
by the presence of the wall.
The effect
anitotropy of
iblv
thickness
outside
direcLion is
adequateo
the computors
of a calculation Lilley:
For example,
the turbulence
for computations
would be wo-thwhile to include this point
o.ibulence outside
P.
no
be affected
omputation.
G.
to amplify
with uniform turbulence at the initial
those suggested here.
will indeed fied
the ef-
theu:, are several other turbulence
bovndary-layec
lence outside the boundary layer is Bradshaw:
ts
specifications
scales
-s
turbulence
than
for evaluating
im wondering whether the data are of such a sort that some such
calculation to start
P.
However,
the skin
possible.
as
ted by
free-stream
suggestions
rati" it
to be considered
you said that
which should be used for a more complete comparison.
cc" mparison
tial
parameter
fi'ee-stream turbulence.
the etfects of
boundary
2.
for a discussion of the Problem,
your specification
frictior
]
to free-stream
the data are insensitive
turbulence effects.
91
.
to the traxisi-
.1
P.
Bradshaw, greater value of
We tried to avoid low Reynolds number data. than 2000,
and comparisons
Most of the data is
at R0
of skin friction are presented at the same
R0 .
P. Champagne:
You mentioned that you would like to characterize
lence by its intensity and dissipation rate.
free-stream turbu-
I would like to define the free-
stream turbulence using power spectra of some of the components of turbulence. P. Bradshaw:
Most of the available data involved measurements of the u'
its free stream decay; hence all you can get out is
the dissipation length param-
eter.
PLOT 1 CASE 0211 FiLE 2
0.2
0
0.1 />
0.0
o'
Q(r) 0
9
92
component and
2
SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/INCOMPRESSIBLE
Case #0211;
P.
Data Evaluator: P.
Data Takers:
Bradshaw
Hancock and others
E.
SIcnra tkL sJmMAI Data tvalu~tori
rl•, 0210.
"91rsct of
P. arsdehow.
ValI
|) t
Turbultace an 16antary L
Free-ftr." 'I...
FfW|
Turbleatsl
mre."@-
[l,
Wo-
Came Data .tsf
~
yon Rig
r
g..try
CP
.
t
htI..
1
C1
&a
Gtk~r N.C.
ti.
CA.. 02;1 ?. Mt~ek &R
1S.ooth.d corve of
ots4ore
"
Plot
Ordinate
Abscissa
Range/Position
.o c ---
1
U
lC
fo
Use Re > 5000 to avoid lcw Re effects.
(7)2
(j7) C Le
X 100
0 <
, 100
u L
69
+ 2 =
Comments
< 2.5
Notation:
Cfo = value 7-
o0 of Cf where u Lu (u-•13/ 2 /(2c/3) e e
+ 2
Special Instruction: It
is
suggested
tk..t
calculations
should
turbulence with rms component
intensities of
length scale to boundary-layer
thickness of
be
started
10, 5, 1, 2,
with
isotropic
free-stream
2 and 1%, with initial ratio of
and 5 in each case.
However,
com-
putors should use their judgment to provide enough runs to envelope the skin-friction curve, apparent
and
it
will
be
of
particular
interest
quadratic behavior of the curve
cal correlation for length-scale to this region;
it
should
parameter Lu = ()3/2/(2c/3) ble with the method employed,
varies with
effect implied by Fig.
be possible
methods
assume
that
reproduce
intensity.
Whatever length scale is
to deduce
length
it
scale
The empiri-
used in
from the dissipation
is
is
alters
not calcula-
of x (actually
independent
free-stream turbulence
3 times Lu (whatever
the value of L/6).
fied at
the calculation method is
Y > 2L"
if
Thus the "free-stream" value should be speciexpected to reproduce this constraint,
93
.
Note
at y values up to 2 or
even qualitatively.
". .-.
the
length
0.4 power of distance from grid) or deduce du /dx from implied e. e
that constraint of solid surface
the
I does not necessarily apply
free-stream turbulence development
If
.
see whether
for small turbulence
see Meier and Kreplin (1980).
calculation method,
to
.-
....
....
.
..
......
I BOUNDARY LAYER FLOWS WITH STREA2{WISE CURVATLJTE Flow 0230 0232, 0233
Cases 0231,
Evaluators: S.
Honami
T.
W. Simon-
SUMMARY
Data sets wise curvature
for incompressible,
two-dimensional
boundary layer flows with stream-
have been e.aluated for their suitability as test cases for comparison
with computational
resulti.
This
report summarizes
that data evaluation.
More de-
tails may be found in the Preliminary and Final Evaluation Reports. SELECTION CRITERIA The following criteria were applied to the available data sets to help :3elect the test cases. The flow must be incompressible and two-dimensional. •ly
destroyed when the
layer fluid,
cross-stream pressure
Two-dimensionality is
gradient acce
'ates
eas-
end'-wall boundary-
resulting in large-scale secondary flow of the first kind.
The data must
show that the effect of this inevitable Gacondary flow is minimal. As a baseline check on the turbulence data, shear-stress profiles taken on a flat wall upstream of curvature must match accepted flat-plate profiles. the data are to be used to evaluate
*Since it
was decided that mean-flow data,
have,
at least,
the-u
The simpler
,-v
,
which
were not sufficient.
for turbulent flow, The test cases
nust
and uV components of the Reynolds stress tensor.
curved-wall cases were given higher priority than cases with curva-
ture plus other competing effects, Cases
alone,
predictiun models
showed the
e.g.,
response
lateral divergence.
of the flow to
the withdrawal
of
curvature
as
well as the introduction of curvature were favored over those with only the introduc-
j
tion of or only the recovery from curv~ture.
tUniversity of Minnesota,
Mech.
Eng.
Dejt., Minneapolis,
55455; formerly Stanford
University. The Science University of Tokyo, Mech. Fng. Dept., Kaguravaýa, 162, Japan; on leave at Stanford University, 1979-80.
Shinjuku-Ku,
94
:; '-::::::::::::::::: ::::::
: .: . - "
; :: :: : :"
:
.
i . : : .:-
-
.-
-"-
Tokyo,
VIEWI
rie
i2ases where the curved-wall
VIM6_
the
sectirs
which showed more the response
introduction
Concave . -*
section was long enough to assess the response of the
flow to
curvature
of curvature were
can
result
favored over
in
to at. "impulse" the
those with very short curved
of curvature.
establishment
of Taylor-GoArtler
longitudi-
nally ro.l cells, making the flow locally three-dimensional. Cases where the influoence ot the roll cells wai large (that were otherwise acceptable) were labeled "Advanced Teat
Cases."
future use,
These
advanced
but were not recommended
cases have
been entered
in
the data
library
for
for this conference.
SELECTED DATA SETS Of
the many categories of flows being modeled in
flow category *
.
reasonably
seems
cussed ab.•ve. common was
concave .
and,
boundary
Introduced flat
by
the most
entries,
layers
to either
recovery
walls did
except
of
we
thoroughly documented.
adopted
the highly
concavely
walls.
ilot merge.
Ef:st developed
were
In In
jr convexly zases
all
all
Case 0231.
the boundary
In
P.
this case,
a boundary
Case 0232. This -"-
I-'
curvature Concave:
case 2.667
ture was ormition
is
layer was
of weak
cave wall.
grown on a
The flow
fnllowed, nn
the
in
convex
mone and
roll cells on the concave walls, The test cases are:
P.
H. Hoffmann and P.
Instabilities
in
69 9 5 1R
cases.
then introduced of 0.0i.
to a
This indi-
There was no recovery.
Bradshaw (1978)
associated
longitudinal roll cells
This resulted
flat wall,
giving a ratio of
than the other boundary-layer
for the opposite wall (concave)
m.
followed a
pre-plates.
layers
dis-
H. Hoffmann and F. Bradshaw (1978)
convexly curved wall of 2.54 m radius,
"cates weaker
criteria
.
cases there were minimal secondary flow effects;
for the formation of weak Taylor-G~rtler
Convex:
order to have a
These cases
flat
curved walls,
the boundary layers were sufficiently two-dimensional. *
on
In
the curved-wall
restrictive
Five test cases were chose7 for this category.
pattern:
then
cases,
to be one of
small number
this conference,
to Case 0231.
with concave
(Taylor-G~rtler
The radius of curva-
curvature vortices)
regular Bpanwise variations of all
resulted
in
the
just off the con-
quantities.
Data were
taken near the spanwise location of minimum skin friction with respect to these weak vortices. Case 0233.
4-_•
In
C. Gillis and J.
this case,
convexly 0.10.
J.
Johnston (1980)
a boundary layer was grown on a flat wall,
curved wall
This
P.
of
0.45
m radius
indicates strong curvature.
of curvature,
a
ratio of
69 9 5 /R
of
Downstream of the bend was a flat-wall recov-
ery section.
95 Ir.
giving
then was introduced to a
.
In
I. A., and P.
Hunt,
Case 0234.
this case,
N. Joubert (1979)
which had a radius of curvature
(to the channel centerline)
At
began to merge about 40% of the test section length.
Smits, A. J.,
In this case,
S.
and P.
T. B. Young,
and
a boundary
layer was grown on a
The turning angle of the bend was
the end of the test section,
Bradshaw (1978)
convexly curved wall of 12.7 cm radius of curvature,
ture.
of 6.35 m and a nominal
There was no recovery.
the flow was essentially fully developed. Case 0235.
a curved channel
The two boundary layers initially were independent,
D, of 6.35 cm.
channel depth,
two walls of
layers were grown on the
boundary
flat wall,
then
introduced
to a
giving a ratio of 69 9 5 /R of 0.17.
This represents a strong "impulse" of curva-
300.
Downstream of the bend was a flat-wall recovery
section.
No data were taken
.....
within the curved region. REFERENCES 'Turbulent boundary layer on a convex of Mech. Eng., Stanford University.
and J. P. Johnston (1980). Gillis, J. C., curved surface," Rep. HMT No. 31, Dept.
"Turbulent boundary layer on surfaces of mild Hoffman, P. H., and P. Bradshaw (1978). longitudinal curvature," Imperial College Aero. Rep. 78-04 (submitted to JFM for publication). Hunt,
'Effects I. A., and P. N. Joubert (1979). turbulent duct flows," JFM, 91:4, 633-659.
of
small streamwise
curvature
on
"The effect of short regions of Smits, A. J., S. T. B. Young, and P. Bradshaw (1978). high surface curvature on turbulent boundary layers," JFM, 94:2, 209-242.
DISCUSSION Flow 0230 D. Bushnell: 1.
Did you consider cases where
the curvature might oscillate
like the sinusoidal
wavy wall? 2.
What was your criterion for "small" Taylor-G6rtler vortices--small
in turbulence
or small in its effect on the mean flow momentum equation? T.
Simon: ture
we did not look at wavy wall cases.
No, cases
and cases
that
showed
the
direct
1'
We were looking for simple curvaeffect
of
curvature
on turbulent
.
structure. On the concave wall it
becomes
the integral momentum equation. spanwise variation
variations in
difficult to evaluate secondary
flows by way of
What we were looking for was information of the
of mean and turbulence
skin friction was kept
quantities.
down to about ± 5%.
In the evaluation,
the
Where Taylor-GCrtler
vortices were considered large they were treated as advanced test cases. 96
ILL
G.
The
Mellor:
So and
Mellor
cells and should
Cdrtler
Simon:
The
case.
the
Gillis
recovery region data, G.
Mellor:
T.
Simon:
"*
there
Are you sure
is
convex
So and Mellor
However,
is
making it
enough
case
is
time
very
Johnston
and
and has
too complicnted
be considered an advanced
and
vex case is simpler, boundary layer. T.
concave case
develop
similar
case
However,
test case. to
has
to
both
large
a
Taylorthe con-
-
quasi-equilibrium
the Gillis and sustained
Johnston
curvatnre
and
the favored choice.
that the 90-degree
bend (of
Gillis and
the
Johnston case) is
enough to e;tablish a quasi-equilibrium boundary layer? We see
that
the
profile
shear-stress
the
profiles of
the
fluctuating
into what looks like an asymptotic condition within about the
quantities develop
15 to 30 degrees of the bend.
first
and
the mean velocity
However,
profiles continue
to evolve even up to 150 degrees.. D.
For computational
Wilcox:
purtJoses,
does
your term "weak
Taylor-GCrtler
vortices"
mean that you cousider these calculable with a two-dimensional method?
'
With
1T. Simon:
a
the additional mixing due to the
mean by modeling
"
method,
layer
boundary
two-dimensional
you will
presence
be
of the
JL!
the
computing
Taylor-G~rtler
vortices. J.
McCroskey:
T.
Simon:
The
compared
well with flow-angle
What
friction?
wall
classical
.
made by experimenters. of skin
Was any consideration given to the methods used for measurement
Narasimha:
.-
these flows as two-dimensional?
method
This
momentum balance.
integral
measurements R.
for certifying
Vhat are your criteria
were
the
similarity
is
valid
not
As
involved?
uncertainties
large
at
there
curvatures,
is
tubes
Preston
A
that
evidence
and
Clauser Dlots may not be valid. T.
The skin friction was usually measured by using the Clauser plot technique.
Simon: 7tough
'
at
curvature,
first as in
test cases.
these
curvature where the boundary the meeting
Following ties deduced
from
it
pitot-static
In
was
is
now accepted
not in
still
commented
to
cases
of mild
probes differ
be real.
"
equilibriua.t
for Cases 0231/0232,
on that
pitot/wall-static
appear
for
does break down near the beginning of the
It
[Ed.:
the
by about
We have queried
veloci10%.
As
this with •-
For most of these cases,
See Evaluation Report. given. ([Ed.:
technique
layer is
and
Case 0141 these differences Bradshaw.]
in
~~Prof.
"[
this
questionable,
the Gillis-Johnston flow,
wall agree with the Clauser repeat tions beyond about 20' of turn.]
Case 0233, value
of
was not
the uncertainty information
extrapolating Tw to within a
IM, measurements few percent
for all
to the 1-_
sec7
97
.
.
.
.
.
.
.
.
.
.
.
. . . :.:.::::::::::: . . . . . . ::::::
..
..
..
.
:
..
: ..:
: :-
..:. .
:.- : :
:.
. _.
.
.
.
SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/INC0O4PRESSIBLE T.
Data Evaluators:
Case #0231;
P.
Data Takers:
H. Hoffman and P.
Simon and S.
Honami
(Convex)
Bradshaw
bl..94AT PICPIJBIAL ?i"
0230.
..t.... T.
net*. 9-
Sig.n a•a 1.
bar o
-in
T..L allnbl.n.2nf~.______
Case___
C... 02 3 P. I
Plot S
V
ICndI Cf
lUthers
I
•2_sI _2_5lui
I
S;
Other Note.
ion
Me I
Iood
PI.2.em
I
,. beL" I nnni
-•
I
"
'
'j
Plot Plthd."
Ordinate
Abscissa
Range/Position
Cf
XS
0 < XS < 1.0 m
H
3
I u V
W
12I
, Molo 2 *ka.
CIO-,
Heasur.d
or-
or
M tti
e-.-.
Stations
Turbulence Proflloe
vaiqcly
get& Taker
"lo-dradsry LOyr f1gme with StreamLLe C¢rvature."
16of....
Comments XS -
streamwise distance on wall.
Curved section begians at
XS
0.
2XS
-0.2 < KS < 1.0 m
Curved section begins at
XS
0.2
XS
-0.2
< XS < 1.0 m
Curved section begins at
XS
0.
velocity of potential
flow
1 -. y/
4
6
U/Upst
0.685, 5
y/6
v 2 /U /Uw 2
Y6
uv/Uw
and 0.99 m
X XS 0.685,
6
Upot -
at XS - 0.076,
.7, 0.076,
Uw U
and 0.99 m
o velocity of potential =
on curved surface at wall.
and 0.99 m
Special
Instructions:
I.
Begin computations upstream of curve as indicated.
2.
XS Mean and turbulence profiles at further upstream. matched for start XS - -0.076
flow
0.076,
XS
0.685,
at given locatiou.
- -0.076 m If matched,
m. can be used to compute Upw.
3.
Cp from data file
4.
Provide a tabulation or curve of output for 98
6 vs XS.
or can be used to start, show values used at start
-
PLOT 1 CASE 0231 FILE 4
1
!
0
0.0030
4
Cf
0.0025
0.0020 0
0.5 XS (M)
1
PLOT 2 CAME 0231 FILE 6 0.004
-
0.003 0
(m)bI 0M
0
0.002 I-
0.001 F
0.000
"1
,-
0.5
0
99
99
(i)
PLOT 3 CASE 0231 FILE 6 3.0
2.5
H 2.0
1.5
o
0
1.0 0
0.5 XS (M)
1
PLOT 4 CASE 0231 FILE 8,11,12 ! I i I I 00
o
0.685
u
0.99
1.00
0
I
0
0.50
o 0
_'
S+
0 0
1
0
]
0~
.
1
.
1I
0.5
PC,
0.01 0
0.15
1
0
0.5
U/'UpoL
100
1
PLOT 5 CASE 0231 FILE 13,14,15,16 I
0
0
0
1.0
0
i0 00
0
y16
J
.,
0
T
0.5
04
Xs -
-
0
t,
0
0.0
0
0.685
-7
0.076
0.001
0
0.001
0
0.99
__
0.001
0
PLOT 6 CASE 0231 FILE 13.15,16
I1
f)
0
10 -'I
0
C
-T
0
00
0.5
r
0*0 0 0
0
Xs-f 0.0
0
09
008
0.076
-0.001
0
_
pw
101
-0.0010
-00L
SPECIFICATIONS
FOR COMPUTATION-
ENTRY CASE/INCOMPRESSIBLE Case
#0232;
Lata Takers:
P.
Simon and S.
T.
Data Evaluators:
Bradshaw (Concave)
Hoffman ond P.
H.
Honami.
PICicIALAL SV4WAT view 0ov%
Dot
e-v a t.
T. stoo
-d
"50-481Y tr .el. L.ye
s.
UtsPlteOdinte Tk.,
¢i-
tryAbcisa
R
c
Mt~tt Plot
U
nge/P '
[
"
IOth,-r'
a
-
-
w-
4
XS
Na Yi6 -V.elocity
v
2
S<
O 0lo,
S2
S
,.
Ntre.ic
U
l.123 mn
at given location, U
0.803,
0 .16,
UIUp 2
pw
XS
-
0.
on S
XS
0..-
of potential flow
0.16, 0.803,
XS
atXI0
Curved section begins at
m
=
velocity of potential
flow
on curved surface at wall.
1.123 m 6
be-n
Curveistanc st-ea.wi-
1.2 m -
-0.2 < XS (1.2
U/U p
y/ 5
y1
Cont'
.'-
-0.2. <
6
Re
Curved soctio
-S
3
r,
dCt'o,
1
_____
1-. Clrf ture,"
ilie,
b•i.......
V.10Tty
wlth tl-ea
Fi-
0.803,
0.16,
1.123 m
Special
Instructions:
.egin computations upstream of curve as indtaated.
2.
Mean and wa'tched XS
turbulence for
start
profiý(cs* aý further
XS
upstream.
--
0.152 rn can be u,,-ed If matched,
show
to start,
or
used
at
values
.
-0 .0152a
3.
cp data from file can be us--d to compute U~m
4.
Provide a tabulation or curve ofcutpur a
forin
. avs XS.
102
.............................................................................
PLOT 1 CASE 0232 FILE 5
0.003
o
0 .
0
Cf 0.0022
1
0.001 0
0.5
1
XS (M)
PLOT 2 CASE 0232 FILE 7 0.004
0
(m)
I
o
0.003
-
0.002
0.001
-,
0
0.5
"XS (M)
1.03 [4
1
PLOT 3 CASE 0232 FILE 7 I
I
3.0
2.5
1
2.0
1
H
1.5
1.0 0
0.5
XS
(in)
PLOT 4 CA6E 0232 FILES 18,20.21 C
I
ic
1s
•;
I
0.0
0- 16--
0.5
Ilk,
I
'>
1
0 803"0
1--12.3 0
"
C'
0.0
-
0.16 m
0
0.5
0.803
0
--
0.5 U .Upot
104
1
1.123
0
0.5
1
L
•~
PLOT 5 CASE 0232 FILES 23,25,26
I'1
0
0
1_ 0
0
0
0 0 00 0
0
0
0
0
0
0
1.
0
0
22
.0
Y0111
0
0.001
0
0.001
0
0
0.001
v-T/Upw2
PLOT 6 CASE 0232 FILES 23,25.26 1
+
1.00 0
•
0
0.o_
0.803
+ ----
.16
_
*1
{
1. oI
..
0.803
"
105
1.123
o
-.,
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOHPRESSIBLE Case #0233;
Data Evaluators:
Data Takers:
J.
T.
Simon and S. Honami
Gillis and J.
P. Johnston
PICTO I kJ.L 12JM AuyI ?l*W 0230.
Dati Ivaluletoj
T.
Sloanary Layer Vlowe with Str*Awlr
woananJd S. IdNO-.
Nlber of Stlo-atin
VolOnty Iwvrknlsnc*
'"C.02""3 Go..lry
DaaT
C:
.
Case 0233
24
.
..W
I1
11
I 2: Ot.n ''C t2 12
ItO1
24'
L.
.6
• 10£ C
te
0.10
oe
qrroni Curvnltre wtlh
loroonory.
. I
plot K¢Chod-
Plot
Ordinate
Abscisba
I
Cf
XS
-0.3
< XS < 1.7
2
H
XS
-0.3
< XS < 1.7 m
3y6
U/Upw
Range/Position
XS - 0.104, 0.885,
y/6
u 2 /U 2
XS
-
5y/6
y/
*
6
y/6
/U w
-XS
"
Comments m
0.415,
and 1.647 m.
0.104,
0.885,
6
2
I.
i
_.
4
Curvstaro.-
Profiles
J. Gillis & JIh ,tv
act. i..,e
s
Mnasos..d
0.415,
and 1.647 m-
2•
XS
a 0.104,
2 0.415,
0.885, 1.647 m = 0.104, 0.4i5, 0.885, 1.647 m
XS - 0.104, 0.885,
L-.
0.415,
1.647 m-
Special Instruction: i.
Provide a tabulation or curve of output for 6 vs XS.
106
.
..
-.
+
.
-e
. . "* . - -
".n.-
.
PLOT 1 CASE 0233 FILE 3 0.006I
I
0.004 Cf
0
'
0
00
0
0.002
0
0
0
0
0.000 0
0.5
X'S (M)
1
1.5
PLOT 2CASE 0233 FILE3 3.0
H
2.5'-
2.0 [
0-
1.5 1
1.0
0
0
0
00
L(n 0
0.5
1 1-07(M)
107
1.5
4
PLOT 3 CASE 0233 FILES 5,7,9,14 , . , ,I ,I j{T 1.5
4-
It
4,
Y164 ot.o
1.0
.
-
0
-
0.5
,
o
1,
j
0.104
0.415
0.88
0
0.0-
o
-
• I
I
1
0
1
0
1.647
.
I
I
1
0
0
PLOT 4 CASE 0233 FILES 17.19.21.26 1.0 4,
I
0
Y16
*
•,
0.5
iL 0.5
7
0.
10
0.41.
&;•
XS
0
5
.0C l
C'. UC'
i_/o
o
000
pw
108 00.00.08
-0
PLOT 5 CASE 0233 FILES 17,19.21,26 1.0
T
0
0
1010 0.5 0
°
° 50. 104a•
0.0
"0
t
0,
+
~00
o :
I
.
;
o
+
0
o
-
1.647
-L
0.002
0.002 0
0.002 0
0.002 0
°
°t 0 0
.4-0.5
0.415
o0
0 t°
i
,,
0
.6
0-
SIpw
PLOT 6 CASE 0233 FILES 17,19.21.26 1.0 L
I
y16
C
0 ,. 0
0
0
1.0C'
0.5-.
0.01,
i
,
o
0.415
00.104
0.0025
.
0
0.0025
o 2-
0.0025 pw
109
1.647
0.885
0
0.0025
lvr1 , 71 -1 1 .7
rv1.
~
.
PLOT 7 CASE 0233 FILES 17,19,2 1,26 1.0
-
o
0.5
0-00.0
1.4 045
7
-0.001
0
-0.001
0
-0-001 11V". U.pw
I 10
0
-0.001
0
•.
SESSION II
Chairman:
B. Launder
Technical Recorders: P.
R. Childs N. Joubeic
6M Flow 0240 Flow 8300
-
Flow 0330 Flow 0510
"I-. .
.
.
.
•.
..
TURBULENT BOUNDARY LAYERS WITH SUCTION OR BLOWING (INCOMPRESSIBLE) Flow 0240 Cases 0241, 0242,
0244
TURBULENI BOUNDARY LAYERS WITH SUCTION OR BLOWING (COMPRESSIBLE) Flow 8300 Case 8301 Evaluator:
L.
C. Squire
(prepented by, E. P. Sutton) SUMMARY There have been numerous suction or blowing
experimental studies of turbulent boundary layers with
through the surf.ce and many of these data sets are available in
numerical form in reports or theses. able form it
was decided to restrict the evaluation to measuremaencs mdde on surfaces
in which the holes, relative
to
In order to reduce this mass of data to mancge-
or pores,
through which the
the boundary-layer
normal to the
surface
fluid is
blown or sucked are'
thickness and are so close together that the velocity
(V) may be assumed constanat locally.
essentially homogeneous
small
and the flow through the surface
the surface is
That is, is
a good approximation
the mathematical boundary condition of specified normal velocity at the surface. restriction allows us to consider
to
',is
flows in which the mass flow rate through the sur-
face varies along that surface1 , i.e., V
It also allows consideration of flows
V(x).
-
in which there is a step change in the mass flow rate at a particular position (i.e., V - 0
for
suction, that
x < X
and
V - constant
for
through discrete holes or slots.
such
flows
would
require
x > X ).
However,
very careful
consideration
specify suitable boundAry conditions and test results. regards It
it
excludes blowing, or
This restriction was made since it before
it
was felt
was possible
to
In fact the present evaluator
these flows as more suitable to a conference on very complex turbulent flows.
should also be noted
that experiments
with foreign gas
injection and experiments
which concentrate on heat transfer aspects of injection have not been considered. Even within this restricted
class of flows
there
is
a large amount of data.
In
fact over 200 boundary-layer developments u±th blowing or suction through porous surfaces tables
have been of
reported
measured
in
the
literature
profiles are
available.
gradient a wide range of pressure-gradient speeds
and
at
supersonic
CAmbridge University,
speeds,
Cambridge,
and
in
CB2 IPZ,
and for many In
of these developments
addition to
flows
in
conditions have been studied, many
cases
the
mars
zero
p
full
pressure
both at low
flow rate through the
England. 112
.-..
%....':'
.. "
.'.
-.-.....
-'-:..".
.......
.-..
.-..
"..
-.-..
,"...
..
_
surface the
varies
same
imply
blowing
that
boundary In
along
the
(or
suction)
results
tha cases in
particularly it
form of
whatover
it
guise
is
tions.
In
in
results.
comparable
spite
is
studies
conditions,
since
comparison
to
be
the differences
in
used,
particular
In
the lack
rather it
of
has
than been
forri
in
many in
to
measurements,
but
cases
inaccurate
this
Kays,
turbulent
measurements
were
and Moffat
k972).
shear stress
In
stress,
obtained the skin fric-
especially
at
the
equation,
higher
*•al.
but
for
it
etill
found
differences
that
some
fitting
of in
data sets
in
the
the actual
with
discrepancies
the analysis of
have had to
and hence the
made
in
the
Basically
be
could
"tions along
with moderate
or
in
because
checking
of
the over-
later
experiments
at
Stanford
the
the
best
In
(1974)
for
rates
various
stations,
coefficients
Of course,
in
zero
was
one
gradients
the overall
equilibrium
with
the shear good
so obtained were in
The agreement was particularly pressure gradients.
chosen
results
layers
to give
Andersen
equilibrium
from these layers were
on
solid
surfaces
All these layers were checked for two-dimensionality, layer
and then
et
also studied a set of boundary-layer developments
pressure
general
results
by
the integrated equations of motion to extrapolate the
blowing
suction with
the layer.
with
other workers.
*
re-
the experimental
rejected
impossibility of
be
these workers measured both mean flow
that the skin-friction
and Orlando et al.
injection
agreement
that
blowing
flow condi-
limited by the accuracy of the hot-wire measurements of
was found
flows
(1972)
-
in
the quoted skin friction may be due to the
agreement with those obtained from a momentum balance. good
the
considering
The use of this
through the boundary layer at
used the mean-flow velocities
method is
*
not
of
number of discrepancies
m casured shear stress away from the wall to the skin friction at the wall.
i*
does
the state
two-dimensionality of the flow.
Andersen,
S.this
to cover
the various experiments.
possible a
equation.
genuine
the
appear
skin-friction coefficients.
of curve
this many of
of redundant
Redundant
~
pressure-gradient
the quoted
tends
moved by using a consistent
.-
the experimental
the momentum integral used,
Thus some of
form of analysis
and
of
should be noted that most experimenters
tion from some
all
and
directly
which a direct
these discrepancies
rates.
are
Some
layer upot-.eam of the region of injection differs
were apparent,
*
the surface.
suction
and
an adverse
as
in good
measurod
and it
gradient.
condi-
by
was found
This
layer
was
chosen for a test case together with one of Andersen's layers with injection in zeco pressure rate
of
F > 0.004
gradient. F
This
0.004
appears
to the flow with
to F -
A wide range of and blowing
in
latter layer corresponds
(F
PwVw/PeUe)
be
two-dimensional.
0.008
pressure
relatively moderate
since unfortunately In
particular
gave significant negative
experimental
favorable
to a
results
is
gradients,
none
layers with applied
skin-friction coefficients.
for
unfortunately
provides an independent measurement of skin friction.
the
the momentum balance
also available but
of
blowing
However,
layers with 4uction none
of
these
tests
the results of Loyd et
113
I'-.
*.
.".-.
and of Julien et al.
al. (1970) Andersen;
the
measurements
fluid-flow that
transfer measurements
were
(1969)
were
made
*
values as obtained
2
( )
,
,
and
W)
these
zero pressure gradient
However,
the original
and the agreemetit
two methods
by
measurements of tuir-
The tests included
bulence quantities at one station for suction rates up to ted that Vthese measurements
Thus
A full check on the reliability of these flows
is excellent.
between the two sets of values
heat-
needed.
not possible since full velocity profiles are not available.
report does quote skin-friction
uv
with extensive
energy balance.
for high suction rates in
set of results
ware obtained by Favre et al. (1966). is
parallel
in
overall
showed an excellent
developments might provide further test cases if An interesting
the same tunnel as used by
obtained in
F - -0.014
It
.
is sugges-
form a simple data set in which the predicted values of,
are
compared
with
the measured
values
for
several
suction
rates. So far the tests considered have been made in low-speed flows so that the effects of compressibility can be ignored. an
extensive
study
turbulent
of
The present evaluator and hia students have made bound-cry
with
'.ayeLs
air
injection
at
supersonic
speeds. A critical study of the results from this program has shown that the boundary layers generated in the N - 2.5 nozzle are closely two-dimensional in that the skin-
"friction
coefficients
on
solid
surfaces
are
in
close
agreement
skin-friction
with
balance measurements made in the same Mach number and Reynolds number ranges by other
'
workers in a variety of test sections. with slight
favorable pressure
used this nozzle to study layers
Thomas (1974)
gradients
for various
injection rates.
He also used
the razor-blade technique to measure skia-friction coefficients on a solid surface for the same presnure gradients and the measured values gave good agreement uith the overall momentum balance. '
Thus one of these layers is suggested as a test case.
However,
in 3pite of the care taken to eliminate spuriouc wave systems in the pressure gredients some weak waves are still present, and these waves affect one or two of the messured velocity profiles. As a result of this evaluation thz following test cases have been recommended. Case 0241.
A flow with zero pressure gradient and constant injection (Y = 0.004) as measured by Andersen,
Case 0242.
and Moffet (1972).
Kays,
A flow with an adverse pressure gradient (U.eX constant suction (F
0
.15) and
--0.004) as mziroured by Andersen, Kays, and
Moffat (1972). Case 0244.
Flows with high suction rates (-0.014 < F) as measured by Favre,
Dumas,
Verollet,
in zero pressure gradient
and Coantic (1966).
114 04.%;.•.-*:
A
-
.
.
. -,44-
.-.
.
.
.-
-,
A
.
.
.
-. ..
at supersonic speeds
A flow with favorable pressure gradient
Cabe 8301.
(2.53 < M < 2.87) and variable blowing (0.002 < F < 0.0028) as measured by Thomas Together pressure
these
four
data
the
effect
gradients,
rate.
Also
some
of
the
sets cover of
completing
this
measurements
the
main
Recently a number of workers
1967;
1979)
considerable can
he
there
used
in
still
'eqt-.
rný!'ln
in
suction
change
quantities.
Thus
layers with suction or blow-
and Nerney, balances
the pores.
a number
WPwever,
of
the
choosing
test
to
problems
cases
and
in
Dershin et al.,
to measure
skin
co
far
fric-
balances show
these
be overcome
obtained
results
1977;
Although
before
do
they
indicato
From these results
between blowing and surface roughness.
strong interaction
step
adverse
lack of direct methods of measuring
(Schetz
blowing through
are
a
turbulent
in
floating-element
developed
surfaces with
promise
of
obstacle
the results has been the
skin friction.
tion on porous
of
and
and
of the various calculation methods.
evaluation
have
favorable
suction,
to cover the main features of
assessing the acccracy of
Voisinet,
and
compressibility
ing and hence to provide a full test In
blowing
include
flows
they would appear
together
(1974).
it
a
would
appear that some of the discrepancies mentioned above may be associated with the different
experiments
with
porous
surfaces
used
and suction
blowing
in it
the is
and
in
roughness
overall
pointed out that it
is
various
recommended
specify the nature of their surface,
care to tion
of
types
believed
that
Thus
that experimenters
in
future
tAke
great
terms of pore size and distribu-
both in
characteristics.
experiments.
In
this
connection
the data sets suggested
should
it
above are not
be
influenced
by the nature of the porous surface.
Finally the evaluator would like to thank workers who have supplied original data and have answered that
a
particular
ments are
flow
considered
which could
is
not
included
inaccurate.
form useful
able value in
He would
his many questions.
In
cest cases if
choosing the
in
the
fact
to empl;asize
data sets does not
there
needed,
also like
are many
that the fact
k
imply that measure-
other sets of
measurements
and these results have bee,. of consider-
test cases mentioned above.
115
i.15.
.• 7-.
"'
"-
-
6'
REFERENCES Ai~derveii, P. S.,
W. M. Kays, and R. J. Moffat (1972). "The turbulent bouiudrry layer on a porous plate; an experimental sftudy of the fluid mnchanics for adversc pressure gr~dients," Technical Report No. 15, Dept. of Mech. Eng., Thermosciences Division, Stanford University, Staaford, California.
Dershli-, h., C. A. Lcona-.d, an-i W. H. Gallaher (1967). "Direct measurements of skin friction on a porous flat plate with mass in-,ectior." AIMA Journal, 5, 1934-1939. Favre, A., R1. Dumas, E. Verollet, and M. Coantin (1966). 'Cou,;he Amite turbulente sur pt-roi poreuse avec aspiration," Travaux dea ll.M.S.T. LA No. 130 au C.N.R.S. , J.de Mqcanique, 5, 3-28. JulenH. .,W. M. Kays, and R. J. Moffat (1969). "The turbulent Loundary layer on aporous plate: experimental study of the effects of a fa~orable pressure gradent"TchncalReport No. 4, Dept. of Mech. Eng., Therreoscienceo. Division, Stanford University, Stanford, California. Loyd, R. J., R. J. Moffat, and W. M. Kays (1970). "The turbulent boundary layer on a porous plate: an experimental study of the tluid dyn~mics with stiong favorable pressure gradients and blowing," Technical Report No.- 13, Lept. of Mech. Eng., Termosciences Division, Stanford University, Stanford, California. OradA. F., R. J. Moffat, and W4.M. Kays (1,174).
"Turbulent transport of heat andA woaentum in a turbulent boundary lay~r subject to deceleration, suction and variable wall temperature," Technical Repo'rt No. 17, Dept. of Mech. Enig., Termosciences Division, Stanford University, Stanford, California. Schetz, J. A., and B. Nerney (1977). "Turbulent boundary layers wi~h injection and surface roughness," AIMA Journal,.15, 1288-1294. Thomas, .D.(94. "Compressible turbulent boundary layers injectioa and pressure gradient," Aero Res. Counc. R & M, 3779. Voiiet
~i.
R. L. P. (1979). "Combined influence of roughness turbulent skin friction at Mach 2.9," AIMA Paper 79-0003.
116
with
:!ombinea
air
and mass transfer on
.
-.--
DISCUSSION Flows 0240/8300
"i
The proposed test cases and the summary report were accepted with the following
I
observations: I.
Prof.
Hanjalic,
who has made computations of Case 0242 (adverse pressure gradient
with suction), section was
believed that the measured
uv
profile near the end of the porous
inconsistent with those farther upstream because it
implied a sudden
increase in shear stress. 2.
It
was
felt that
the
levels of blowing, near-wall
region
computors
adopt
success
in
test cases,
because
they considered
only rather
moderate
effectively provided only a test of the modeling of the very of
a
the
flow
(i.e.,
bilogarithmic
predicting
Cf
the
near-wall
will depend
viscous
and
matching
in
predominantly
"buffer" the
layer).
If
calculations,
the
on the choice made for
the
+
dependence of the additive constant in the bi-log law on Vw" In examining the variations in skin friction from flow to flow,
3.
review committee There
is
felt that there was perhaps an overemphasis on Cf measurements.
generally
profiles,
good
consistency
between
different
experiments
even at higher blowing rates than have been recommended.
boundary layer with 3trc;ng blowing: just the development the wall • '- otress) would be required of computors. Regarding rather To
future data,
mcdest,
separate
a
low
feature
was noted that the R that caused some
Reynolds
number
Consideration
effects
case,
of mean velocity
a
(not
for the present test cases were
difficulty
in
from
strictly
those
starting computations. attributable
to
arty future measuremencs could hopefully be made with a substantial befoce blowing or suction began in order to permit the
transpiration, impermeable
it
on velocity
as an additional (or alternative)
could thetefore be given to including,
4.
several of the
section
attainment of higher starting Reynolds numbers. model that could accommodate
(On the other hand,
a turbulence
low Reynolds number influences without blowing ought
also to be able to handle them in a transpired boundary layer.)
7-"
,--
117.
j~, ...
. . ". . .
.
.. .
.. ".
-•
..... '-'-,
.
.-.. .
'. .
...
.
...
"..
....
"-.
"
".
" "°..
.
.
.'
. .
. .'
..'
.. " °.. °-
-
-
.
"
.
"
.
.
- .
" .".
.
.
"
'111
SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/INCOMPRESSIBLE Data Evaluator:
Case #0241; P.
Data Takers:
W. M. Kays, and R.
Andersen,
S.
L.
C.
Squire > 0),
(ap/Dx
Moffat
J.
(F
-0.004)
PICTORIAL 5409"IT V|w 0240.
tort L. lquLre.
Date Ivl.
1
-,.fta.i
11
W. r.alt
-
wr
I.C
.
ored
1
I
PYO
-+
-'1 Co41
1..7
w
t-
tohc., Wt1..
"
1
-'--......t-----
Wlearies ( 4 0.0$
per
0.004 .2.1
.
Plot
Ordinate
Abscissa
1
Cf
x
2
-
M
or
-r
0i'.i Data
A.". "P.
Velciy
or
TiPt all
Lay eyrs oLLh SI tloa or Blwiagt."
Ilmbr of lit-tlI
dp/dC...
4
o~ lh
"Turbuleat
Comments
Range/Position 0.0508 < x < 2.286
111
0.0508 < x ( 2.286 m
ux I.-.
3
6
4
v
0.0508 < x < 2.286 m"
U/Ue
at
x - 0.5588,
1.1684,
1.778,
2.286 m_*1
Special
"
Instruction:
Definition of Special Symbol:.; p Vw Aw P U e e
• F1
.-J
0118
; . .' 1 j
PLOT 1 CASE 0241 FILE 2 0.003
o0
0.002
Cf 0.001
0.000
-J
I
.
I
I
2
1
0
.
x (M)
PLOT 2 CASE 0241 FILE 2
0.010 Co O0
o
0.005 o 0 0
0.000 0
2
1 x (m)
119
,
PLOT 3 CASE 0241 FILE 2 0.02
0.01
0.00 02 x (M)
PLOT 4 CASE 0241 FILES 5,7,9,11
to
1.10
x
-0.5588
~-
1.1684
a
yx
0.040.04
1.778
t
()
4 ASE-4 ot-
0.00
.9
"I.0
.
,,t ",
c-
'
+
IES579 St
C' +
f+0
~2.286
-
A
4.
TT
_T••
,,, ",
U/U 120
SPECIFICATIONS FOR COMPUTATION
ENTRY CASE/INCOMPRESSIBLE Case #0242; Data Takers:
P.
S.
Andersen,
Data Evaluator:
W. M. Kays,
and R.
L. J.
C.
Squire
Moffat
(Dp/ax
U), (F
--0.004)
PIC~TflAA,b 144A64.8. Pluo 02A0.
Vue KwaiL.tort
h
P. Aadorsou V: Kays
OL . ddCs7 L yero
<
Ordinate 1
b S.itAl
C or vi
8,°*g..
o 0 I-a. ad t
Por
A Caseu0341
0.O0
Plot
-t •rbulat
1
i..tloaF
,
Lq4airs.
L.
-0.004 (
j
2.2VL .
[
•.-
Abscissa
Range/Position
Comments
0.5588 < x < 2.286 m
fx
2
3
x
0.5588 < x < 2.286 m
3
6*
x
0.5588 < x < 2.286 m
4
y
U/Ue
x
at
- 0.5588,
21.1684, 1.778, 2.286 m
Special Instruction:
Definition of Special Symbol:
K
Fu
pu
__
/
t*-,.....121
Ali..
.
.--
-..
..
-
PLOT 1 CASE 0242 FILE 2 0.010
-
0.009
.--
CfL
0.008
q
0.007
-
1
0
,2 0
0-'.0064A
-i
PLOT 2 CASE 02402 FILLE 2 0.0025-
0.0020
0.0015
0
0.0010 0.0005
IL'
0.0000 .
0
.
.
.
.
..
1
..
2 x (M)
122
:i"I _ _ _ _-" _0242 _ _ _ _ FILE 2 PLOT 3 CASE
'" '._
0.005
i[t
0.004
"0.0
".
0.00300
0.002- I
-
O
L
.
-1
0
0.000
m
1181
-.
0
1
'5
2-
x ( in)-'.
PLOT 4 CASE 0242 FILES 5,7,9.11 0.04
-
x
-
d(
2.286
1 .778
-
.i684 i:
0..5588 -,
o%
o 1)
" i
-.
0
0
00
ol
(..-.
.
ci(
*1.,.
0.
0o ¢'I0
0
(.,
.
I0
O
I
1
10
0
-0'
10,:
'
, -o
,'_ --. - -'
'_
o
L1 Uo
$-" - , ,
.
0"
0
;-, .- " -. -.'" ,' ." -
,
U,,"
' '.
.
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.
.
.
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. . 123
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.
.
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.
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.
-, '
-..
. . . * . * . * . ~ ..* . ~
•
*.
. .* , .
..* .*
.1
.•
.1
SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/TNCOMPRESSIBLE Case #0244; Data Takers:
A.
Data Evaluator:
Favre,
R.
Dumas,
L.
E.
C.
Squire
Verollet,
PICTORIAL SIKhIMY
f ~*asd
Flow 0240.
Dots Sw.1vaCers
L. ISqire.
Velocity
C464
Tort
Tekr Cget& a..
oI C
io
Q...try
T.."
"i
Si
I
/I
M. Coantic
-(
"Turbovuet lowai4ery Layers with Suction or BlowinI."
of
°-
Itetior. b4..sured
TwL.m.-
-
2
U
'
A.-F Lj
1
U
p
,
-h
i
l'
II
I
ProfitL..
*.1~ 1
I .2 o
1
o I cjI'
,a.
td
I
tpr q
a
;
IiI
pMI. Io ., ..... Other ______._,.,
• -
*•A .. Ctto,
. Verolliet casoliI
"
Velocity sod t trhulcacc ric d to 044 dat, fceet
3.
Plot
r.t°..
o,- -u.002. ;.:. I, -0.0053, .o-o
Ordinate
7_
Abscissa
Range/Position
U/Ue
x - 400 mm
C rments F - 0;
'
-0.0142.
0 < y (6995
(2)1/2/U x
400 mm 0995
(v2)l/2/Ue
x - 40
Uv)/e
mm
F - 0; -0.002; -0.0099;
-0.0053; •l
-0.0144.
F - 0; -0.002;
-0.0053;
-0.0144.
0 < y < 6995
-0.0099;
x w 400 mm 0 < y < 6995
F - 0; -0.002; -0.0053; -0.0099; -0.0144,
Special Instruction: 1.
4 plots for 5 suction rates.
2.
Start computations
at
x -
-0.05
m; use or match initial condit'ions at this
station given in File 1. Definition of Special Symbol:
.. *
F - °Wwv" PU
124
.........-
~~. ... .
.
.
.
. ....
. .
.
•.
....... . ,i•-i.;•:i
""
. ".
.
..
PLOT 1 CASE 0244 FILES 8,9 0.04
-4
-
F--0.0142
7-'--0.0 0.03 y(m)
--
°•
-
-7
Q1
0.02-
,"i
<
0
0
C'
I
0.03
0
0
0.0 10 -
OQ
0
-00 5".ogi 0
-000 0 05 0
F.0 -0..
1
.
- .'4
0.5
U ,iUe
J
O
1
00
o
PLOT000 2 CASE 0244 FILES 3-7 0.02 •
0.030
o
-o,-
-
o
y..,.)
i
o
o"
o
o
,,
-:-
0
to
o
.
,. 0.02
•:-
i
0 0
,T
00
c
00
0.1
0
o0
.0.01 %+•.-:0
,0
0 0
0
"IP .
-
"-°.
0 0
0
(
0
0 0
::
0o
"
*
I--
,
-0.0:44
'-0.0099
-0.0053
!-0.O02
•...F:O.
-'.
i
i,
-i,
0_:
0
-
0
0 o0
;T
0
,1
00
-
0
I
o
o125
:
0
0
1
,7Ti
:..:0
01
0
0.1
1
",,":
0
O.1
'/L~
125
. I-2i
0.1
0
0.1
0
(u)
"...'.
"
,.
___-
. .
•
.. *
-
__
_
.
"
-.
F-:?
PLOT 3 CASE 0244 FILES 3-7
I-O2 -0.0053
F=-O,O
"0.03 Fo
i
+0
y
1*
"0.02
:-::::0
0
f
0 0
j
L
o
0
0
0
o'
o00
0 0
4
"
4
0
0
0
0
0
o0
4
<
0
I
0
0 0
'
0 0
o0
I.•,
__ _
,___ __:___
.
0.05
0
0.05
0
005
0
0.05
0
.
0
o
o
0
.
0
0,0
"00.05,
To
j
0
,
0
0 0
0
-
0
0
0 0
0
0
0
0
"
-r1 0o+ I 0
0
+ 1
1
o
0
,
-- 0.0144
-0.0099
PLOT 4 CASE 02-4*1 FILES 3-1 Si..F
,'
';4
0
=- O.O
4C
'
,-0.002
.
o
-0.0093
-0.0033 I"
"
:''.003
0o
,'
:o
qJ0.02 , •.,
o
•,, 0
A+
I
2u, /
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0
*
i
0
0i
0%I +
o
0
--
•"'10
-
0
.
0
o
-u0.044
,-
':
0lO
i
+
*0T
[
vy(m)
I
Z .,,',
1 C,''.
0
0-
0
0
0
.. '
0
o
0
L .-
C-' 0
0'
0
¢
I:::I
"
0
"
0
-
,1
0
0
"---"+
0
"
0.002
0
0.002
:-...'.
0.002 0 0 -2uv/de2
.-. ,,.-...-.-.-.....:......--- ,..-...
0.002
0
0.0 82"-+
~126
P": :
-.. -.....
-..-...*.--
.:
-
..
-. - .- -.
-:
-
-:
-•-
T'
"
-
1
-I--
0.00 L
•
0 '
.
"--
*....'',
-.-.
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case #8301;
Data Evaluator:
Data Taker:
Pie. MO0. bats 9vol..atsfi
L. lemire.
or
Ibt
(
ocr
oatr C..
0. Them"
,
91ock.. 0
Plot
Lig
Ordinate
G. D. 11iomas
*Tirbdelet be..dary layers with Section of blowse4
Velocity C..Yost Data Tae
L. C. Squire
at leeecs~.
Turhuletre Profles
~
-Ced-4
Other H.94
tiLoe
1--------------------------
----
10
(2.S3
12.01)
LL.kPar
co
dateaetilebte 0. file.. No to-b..Ie.
date.
I
0.02 < V K 0.0028 < 0 .121a
Abscissa
6*
R~ange/Position 0 < x <0.127 m
Comments Take 6* as 0.003 m at x as. ("false" origin).
2
0x
0 < x < 0.127 m
Take 0 as 0.0006 m at x ("false" origin).
3
y
U/Ue
at
x as0.0381,
0.0762, 0.127 m
Special Instruction: None.
127
0.
PLOT 1 CASE 8301 FILE 2
0
0050.1
0
.1
0.5
0.050.
0 '9
.12
~x
(in)
PLOT 3 CASE 8301 FILE 3 0.127
x-0. 0381 u0.0762
&010
0.
00,
129
o
7.1
FREE SHEAR LAYER WITH STREAMWISE CURVATURE Flow 0330 Case 0331 Evaluator:
P.
Bradshaw*
SUMMARY
SELECTION CRITERIA This is a one-lab experiment alternative experiment, by Wyngaecd only,
and
the
turbulent-energy-balance
high turbulence In
the
results
are dubious.
intensity should be no worse than in
region
± 10%; uv,
(Castro, 1973; Castro and Bradahaw, 1976). The et al. (1968) contains measurements at one station
of
maximum
± 15%; triple
shear
stress,
products,
Hot-wire
errors
a plane mixing loyer,
uncertainty
estimates
are
as
due to
Flow 0310. u2 ,
follows:
± 20%.
FLOW SELECTED Castro and Bradshaw complete
form
to
took some trouble
be usable
fully used the data. analyze
the
results
are plotted
for
test
cases,
The only serious
flow in
centerline.
respect nmates
semi-curvilinear
For
this
to polar coordinates
for the
and Gibson and Rodi
curvilinear coordinates. in
straight
meeting,
their results in (1980)
In
Castro and Bradshaw
(s,n) coordinates, the
data
s are
the
n
success-
the need to
(1976)
the main
line being a
constant
line being perpendicular
presented
as
further downstream.
and quantitative details are given in
have
0
-
in
Castro
for the curved portion and rectangular
portion
a sufficiently
drawback to the use of the data is
nominal curved centerline of the layer, this
to present
Figure 1
(1973),
to
with
Cartesian coordi-
shows the
flow geometry
the data file.
ADVICE FOR FUTURE DATA TAKERS The
comparison ments ment initial
in
presented
experiment
no
between place and curved
highly
turaulent
on an unstably region of
flows was
layera
the absolute accuracy
not too serious
curved mixing layer would
a wall
jet
and since
special difficulties
on a
a question.
it
was
of hot-wire
measure-
A companion experi-
be valuable and could be set up as
convex surface
("Coanda
a
effectively
nozzle").
the
Boundary-layer
control might be needed on the nozzle wall. Since the pressure diflerence
across
the shear layer
strictly be computed by using a Navier Stokes code: the calculations,
it
Imperial College,
will
be
advisable
Prince ConsoLt Road,
to assume
London,
if it
was considerable,
it
the pressure field is be
to
SW7 2BY,
atmospheric
should input to
at the outer
England.
130
•
..
.
.-.
..
.
.
.-.
-
-1 2* edge
of
the mixing
layer,
curvature of streamline;
3
with
2
3
AU /R
p/ n
,
where
R is
the
local
radius
of
the radius of the "reference streamline" in the inviscid flow
on the high velocity side of
the mixing
layer will
not
be
an adequate value
for R.
Calculations of this flow,
using an assumed pressure variation,
have already been made
by
Fluid
in
Gibson
and
calculation reference the
nor
Rodi in
(J. a
"thin
Mech.,
shear
press).
in
layer"
Neither
calculation
streamline be used as a boundary condition:
predict~ons
of
pressure
variations
in
the
"still
should
air"
on
bleed"
floor
x 0.04
.he
displaceuen,
backplate
can
be
taken
as
Uref
the
Navier
pressure
Stokes on
the
this would inevitably lead to
The rate of volume flow through the "boundary-layer and
the
the
low
velocity side.
in the corner between the m
per
unit
span;
the
thickness of the boundary layer on the floor and on the backplate can be
neglected.
1
In addition the
to the coordinates
results in the (s,n/
from
self-preservation
nuantities
are
the
present
computors may care to examine plots of
) plane used by Castro and Bradshaw; this shows up departures
immediately.
resolved
shear layer so that uv, in
6
specified,
with
respect
for instance,
coordinate
Note to
that
in
Castro and
a nominal
but
3radshaw's
plausible
plots,
centerLine
of
all the
has slightly different numerical values to those
system which has
been
chosen
for geometrical
convenience
rather than physical significance. REFERENCES Castro, I.. thesis, London,
r,•
r
Castro, ]mixing
I"•'
I.
P. (1973). available on SW7 2BY.
"A highly microfiche
distorted turbulent free shear layer." Ph.D. from Aeronautics Department, Imperial College,
P., and P. Bradshaw (1976). "The layer," J. Fluid Mech., 73, 265.
turbulence
structure of a highly curved
Gibson, M. M. (1979). "Prediction of curved free shear layers with a Reynolds stress model of turbulence." Presented at 2nd Symposium on Turbulent Shear Flows, Imperial College, p. 2.6. Also, M. M. Gibson and W. Rodi, J. Fluid Mech. (in press). Wyngaard, J. C., H. Tennekes, J. L. Lumley, and D. P. Margolis (1968). turbulence in a curved mixing layer. Phys. Fluids, 11, 1291.
131
["'•
131
F".
SI.
"'Structure of
4
U, U
Vv
ORIGIN OF POLAR COORDINATES
E 0.126 m
-
Ir 'CY
NOZZLL LIP
E C\) IC'
'-REFERENCE
Y BACK PLATE-b STREAMLINE
0.447 m F LOOR"
132
#1 DISCUSSION Flow 033C
r
The experimental dita were accepted as providing a valu~ble test case. and
discussion
on
centered
to extend
*,
the
line and the
"the
backplate
domain
to
boundary walls (Fig. and
The committee
the
"reference
streamline*"
providing elliptic
that persona
calculation
this Information in
if
was
the
for com'putations made with an ellipric
internal boundary condition The conclugi(c
whether
flow
iYould
include
the
1).
Accurue
thus
be
provided
Questionb an
adequate
treatment.
analyses dould probably prefer
iegior, between the
referen-e
stream-
data of the mass outflcw rate between
required;
the evaluator
agreed
to
include
the specification.t endorsed
the suggestion
that computors who tackled
this
flow should
-
-
possible also examine the mixing layer without curvature.
--'
i,
".q
S-
.
1•
•
An incorrect c~pecification would mixing layer. *
(Ed.: tion.
The specificntian hua
mainly
show up as
been modified
I 133
spurious
y-displacemcnt
of
the
Lo allow one suggested form of computa-
I=
I. SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPKESSLBLE
CENTRAL,
D10te
0))0.
rFi
lvoloutor
6
D
|
SInlP.'lot
OrdinTest
Scott.- Its
• Iba,
VI
acurC
Layer with strr..
-Fees-J•her
P. ars4oshv.
dod
If
,
Castro
P.
I.
Data Taker:
Bradshaw
P.
Data Evaluator:
Case 00331;
I
vature.t
........ Oo
I
profiles
.
I
tt
ts
Cromn
sa oRange/Posio
aIt
'o
o
.:.n
;d t t
rCastroI•.~~( n
2.
rb-,a
lll~•a
07
1ANrOU0/1 &.,.i tsl are Platt"~ Is
SPlot 3
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IIwolll
- - -1di ete; the
r (o,..)
Ordinate
Abscissa
r
U /Uref
n - 0
Tt 0, 30, 60
17
r17Fr 17 1
ina oonifts Crrd
lint bel
c-lalr|r~ln
<
r
<
rmax
r 0 < r <0.2
1U/2 ef
.fOe 0..I .
ofI the sizinglayer0.
For
6 - 0, 30,
60,
90.
For
U
0 ,
30,
60,
90.
For
0
0, 30,
60,
90.
-
::'•
0.708
4
y
U/Uref
0 < y < 0.225 m
For
x - 0.352,
0.556,
5
y
vI/Uref 22
0 < y < 0.225 m
For
x - 0.352,
0.556, 0.708 m.
_< 0.225 m
For
x - 0.352,
0.556,
0.708 m.....
0 < y < 0.225 m
Fur
x
0.352,
0.556,
0.708 m.
0 _< y "-=•T6Yv2/Ure2
-7
2 3
V/Uref
y
.
Comments
0 < r < r,,, 0
cIIrdI net o.ll~
I ++"'rln 1.. Iý
Range/Posit ion
-u-eur/U~ef
•"2r
(.levl
i.. I I~,. L m.+Io I* o-l.l
Isoono lloon;(o
"Wadohdat-K
30, lorc0 60, I 90.
=
n.
"Special Instructions: *•
I.
*
Note that
two coordinate systems are used:
in curved section (Plots
6; in straight recovery section by x (Plots atave; plot in straight section runs leftward.
* .by
2.
4,
5,
0);
1, 2,
see sketch
3)
given
in Summary
Uref is numinal speed at nozzle exit. gymboIn:
Oefinitione of Special
to nominal
curved centerline of shear
n
distance nor.al
R
radius of curvature of a mean streamlIne
r
polar coordinate:
a
distance
along shear-layer centerline
distance
along
.
see Fig.
the
with nozzle tipper
-
layer
backpl.ate
from nozzle
measured
positive
lip (upward)
from
.in
origin
level
Itp 134
)•lot - I-
-.
+1 y
diatance from the backplate measured positive,
z
coordinate normal to x and y
Uref
reference velocity
e
(nominal nozzle exit speed)
polar coordinate:
see Fig. 1
Ur,
U0, U, V,
u,
v
see Fig.
leftwArd
(horizontal)
1
Io
-
PLOT 1 CASE 03031 FILES 20,23.26,29
Fr
025
G
700
7
L
C
90
03
0
0 0//
'I
or
0)
ref
135 %i
PLOT 2 CASE 0331 FILES 20,23,26,29 Ii
I
I
I
"
0 0
0 00 0
0
0.25
0
0
oo
0
r
0
0 ~0
0 0
0
0
0
0
0
0 0
0 0
0 0 0
0.20
0 0
I"
0
I0 6
0
!
30
0.01
0
60
0
.01
0
02
+
00.01
90
0
0.01
-UG-r/Uref
PLOT 3 CASE 0331 FILES 20,23,26,29
r
'i
0
_o
0.25
0,A 0
10
100
o
0
o.
_.._
0
K.0
4
I
-4
0
-L
0
20
t
t .
rO.l
-0
'I
30
0
60
0.01
0 /
ref
136
T
0.0]
o
0
90
001
I'i PLOT 4 CASE 0331 FILES 31,33,35
•
,,
O. •
T.
C,
-
*o
'0
o'
0.
i
"'.
0.708
0
0.352
0.0
0.
0
0.1.
PLOT 5CASE 0331 >ILZS 31333 ,¢,,
-0
0
-C.'
C-
o56•
0.0,.
-..-..-
C-r 0
00
:
00
001,
0.2.
00.0
u
3--
-.
0
/U r reflo vi 0.T60.0
010__
00
001
2
137
137 --
*.-..;-,-,-.
-'
. I
*
.
.
.
.
.
.
.
.
.
.
.
_--*
PLOT 6 CASE 0331 FILES 31,33,33
I I
I i
-
.'-t
0.2
i 0.0
0 .3 5
0.
I
0..56
S~0I 0
0.1
0
0o
,
0
0.0
.2
I
0
0
0
S0
0
i
50
0 l0.1
o
-
0.0
00
0
.1
00
.
II
PLT
l
CASE '7
031ILS1333 0
!•
f)
)
02.
--
..>-
113 _+
.,
0•
,0
'
*
'2
:'-o .
.,
IA' --
__138
It.o
TURBULENT SECONDARY FLOWS OF THE FIRST KIND Flow 0510 Case 0511,
0512,
Evaluator:
R.
0513
B. Dean
SUMMARY
"_
INTRODUCTION In
flows
layer, a
as
plane
in
flow
turbulence
of
the
to
the
first
as
suggested
the two
that
Thi"
ot
evaluation
the potential
flow outside the
while
secondary
by the time-averaged
(1952)
Prandtl flows of action of
defined
this
second kind
the
as a
are true
anisotropic inhomogeneous Cebeci and Bradshaw
a straight rectangular duct. flow types should be described
secondary
boundary
the pressure field induces a time mean flow in.
flow direction.
kind,
for example in
flows" and "stress-induced
as Tskew-induced
(1977)
secondary
flows," respectively.
experimental data
is
conc-rned
only with
secondary
of
flows
and data have been sought for the following types of flow:
kind,
first
main
phenomena produced
turbulence,
the
curvature of
lateral
a curved duct for example,
perpendicular
secondary
have
exposed to
"Nozzles Curved ducts of arbitrary cross-section S-shaped ducts of arbitrary Surface-mounted
cross-section
bodies
Wing-body Junctions Turbomachinery A
large
fifty
number
years,
around it
have
experiments
and a In
reviewed.
of
considerable
addition,
the world were
would be cuitable,
twenty
consulted,
been
number
carried
out
of references
individuals at
in
these
(totaling
universities
flows
several
and
in
the
last
hundred)
were
research
and their advice on availability
hac bcen extremely usefu!
during
of data,
laboratories and whether
reaching the conclusions drawn from_
this survey. CRITERIA OF SELECTION The
main
objective
was
to
well as mean-flow measurements, "
In
view of
1970
papers
the complexity and
*Atkins Research
reports
of
in
this
uere
& Development,
locate
references
wiich contained
turbuleice
data,
as
sufficient quality and quantity to form test cases. class
found
to
of
secondary
contain
Woodcote Grove,
flows,
mean-flow
Ashl2y Road,
the majority data
Epsom,
only.
Surrey,
of
the pre-
Theq!
KTI8
were
513W,
England.
139
J .- •-.
•..
.
.
•
"-,
therefore discarded as data sources,
but many were clearly of a high standard and have
been used in the development of very useful calculation methods for the design of turbine cascades in turbomachinery,
for example.
Ideally, suitable references would contain total and/or static pressure distributions
and
Reynolds
profiles stresses,
of
wall
shear
stress,
mean
velocities,
triple products and intermittency.
turbulence
However,
it
intensities,
soon became clear
both mean-flow data and Reynolds-stress
that the minimum requirement of
measurements
would be met in only a few cases. Documentation of data was also an important criterion. details of reference
lengths,
It
is
essential to have
velocities and pressures used to normalize the data,
well as the author's interpretation of the uncertainty in the measured quantities. a check was made to confirm that
addition,
as In
extrapolated to the wall agreed with
uv
wall shear stress measured by other means. As
a
reviewed, body
result only
of
applying
these
three emerged as
junction by Shabaka
criteria
possibilities
(1979),
the
the
for
large
(1980)
Case 0511.
1979)
test cases.
(Shabaka,
(30"x5")
wind
tunnel,
long followed edge.
which simulated the body
by a section of constant
the corner of an idealized
surface and spanned the
full 0.127 m
thickness
0.0508 m (2")
and a blunt trailing
All tests were carried
on analog
tape and
linearization, included
(-uw)
on
the
all. triple
determination ,*
and the
The wing had a semi-elliptical ieading edge 0.1524 m (6"*)
able care was taken in obtaining
*
(1977),
out in air at a nominal tunnel speed of 33 m/s Considerft/sec) and a Reynolds number of 1.1 x 10 5 (based on wing thickness).
(100
*
These were the wing-
Nine measuring stations were located upstream of the wing leading edge and nine
downstream.
ded
references
The wing was fixed to the floor of a 0.762 x 0.127 m
1).
height of the tunnel.
(5")
of
but with a thin inlet boundary layer.
Shabaka carried out detailed hot-wire measurements in wing-body junction (Fig.
number
curved square duct by Humphrey
same curved square duct of Taylor et al. Wing-Body Junction
to
of
asymptoted
the hot-wire data and anemometer outputs were recor-
later transcribed main
Imperial
products,
to digital
College
flatness
tape for
computer.
factor,
and
turbulence
including
measurements
The
intermittency.
cross-wire
and the wing main shear stress
the tunnel main ahear stress (-uv) reasonably well
The
processing,
to the Preston-tube
data measured
on the respective
surfaces. The boundary
the streamlines in the tunnel-floor
results show that the lateral skewing of layer,
cauoed by the wing
corner flow.
It
lent
energy
kinetiz
is
leading edge,
induces streamwise
vorticity in
the
also found that the ratio between the shear stress and the turbuis
constant
over most
of
the
flow.
except
close
j
.
junction.
A!
140
-"
•
to the corner
.
Adequate edge
can
be
initial
large distance start
of
the
of
the
as
this
pressure
to
edge,
interest
dimensionally sonable
it
could well
should be started at
by
test
treating that
half
case.
the
pressure
gradient
machinery),
the
ating vortex
on
the wing-body
on
the
pressure
strength.
the
the
the
quasi-inviscid
it
is
be
the
leading but
at
a
used,
or
thickness
that
which are
calculations
the leading edge.
it
could
as
a duct.
every-where
calculations
predictions
suggested
station downstream of
may
of
leading edge
vortex-decay
Instead,
be
calculated It
on the
The one-
would be reatunnel walls
is
floor at the maximum distance from the wing. Junction
flow.
fields have
In
should consider most
practical
a significant
More information on cascades which gives
in
interaction
thu wake
corner
in
tunnel cross-section
equal to that measured on the tunnel Further work
of
upstreAm
recommended that computations should
errors
displacement
the
not
jeopardize
p(x)
beginning
downstream
is
the second measuring
distribution
assume
calculatic.i
However,
leading
in
a
measurements
leading edge
primsary
measured
for
from the
from the wing.
upstream
around
profiles
inferred
the
effect
of
applications
effect
in
streamwise
(e.g.,
turbo-
intensifying or
attenu-
these effects would help in understanding rise to "end-wall cross-flow" and leads
to reduced performance in gas turbines said similar multi-bladed turbomachinery. Case 0512.
Curved Square D'uct (Humphrey,
.umphrey tities
in
Water
a
was
1977)
used laser-Doppler velocimetry to measure mean-flow and turbulence quanduct
of
employed
square as
the
cross-section
(0.04
x 0.04
fluid medium at a bulk
m)
with
a
average velocity
90'
bend
(Fig.
of
0.89
1/s and a
2).
Reynolds number of 4.0 x 104 Considerable in
the
laser-Doppler
scatter This
care was taken to set up the experiment.
optical
choice
by Durat
of
instrumentation
et al.
(19i6)
Measurements the
90*
were
configuration
high signal-to-noife
around
system
in
with was
water
definitely
not
Gessner et
al.,
Ux,
bend,
at
U01
of
U (r,z), z
been
fully
and was
much less
this station are -• u2(r,z), z
on the
where
Ur
u 2x
U
signals
are
a
fringe
mode
forward-
signal-processing
successful
21, u uur were
but wall-shear-stress
1979),
probably be
All known sources of error
employed
use of
system.
frequency
essentially
trackers
continuous with
ratios.
of
have
This
frequency-tracking
based
data
obtained
are absent.
tour
at
No comparison
stations is
there-
of Reynolds-stress data to the wall.
A major shortcoming is the fact bend was only 45 hydraulic diameters.
would
Q. ,
a
flows,
fore possible with extrapolations *
considered.
that the inlet straight-length As pointed out by F. Gessner,
developed
at
influenced
by
significant
at
the
entrance
the
btnd
x/Dh -
to
Itself.
-2.5,
the
tangent to the the flow would
bend
This
latter
but Humphrey's
0
=
0*
(sec
influence measurements
to U.: and u x2 . In fact, he did not measure distributions u---u(r,z), and -l-u--(r,z) at any station, so the starting Oz r z
limited
141.
'.
II conditions
for
"k-c
and higher-order closure models cannot be specified satisfac-
torily. A solution Melling's This -'.
to
(1975)
This comparison was
already
36.8 duct
coincides
that the two
clude all
impasse,
data at
very nearly
states
this
suggested
diameters
with Humphrey's
by
F.
Gessner,
downstream
of
position of
the
x/Dh
is
by Humphrey in
-8.2,
-
three mean-velocity components
and
his thesis.
employ
square duct
sets of data agree quite well at a comparable not presented
to
A.
inlet.
and Gessner
Reynolds number.
Melling's results in-
five of the six components of the Rey-
nolds stress (vw excluded). Humph.:ey's
measurements
provide
a
clear demonstration of
secondary
flow of the
first kind arising through an imbalance between centrifugal force and radial preseure gradient at the side walls of the bend.
strese, while stress-driven secondary flow of the second
kind was
in
probably negligible
wall.
fluid
to be
Similarly,
driven
stabilized
at the inner-radius %i
responsible for strong cross-
stream convection of Reynolds
containing *
This motion is
wall is
the
bend.
from the
The
result
outer-radius
is
for high kinetic energy-
wall
towards
the
inner-radius
flow with a lower level of kinetic energy of turbulence convected by the secondary motion into the core region of
the flow and towards the outer-radius wall. Further work on the flow in the curved duct should include measurements of the component velocities Uz,
*.
Also
needed are
"
determined.
u 2z
and uouzin the upstream tangent,
wall-pressure
data
so that reliable
-
values of skin friction can be
From the point of view of engineering applications,
stream of the bend is of equal importance, least 40 hydraulic
diameters would help
z
as well as in the bend,
the flow field down-
and measurements throughout a length of a,,. in understanding
how the flow recovers
from
the effects of the bend. Case 0513.
Curved Square Duct with Thin Inlet Boundary Layers (Taylor et al.,
Taylor et al. (1980)
* duct
(Fig.
2)
as
1980)
have carried out a further series of experiments in the same
Humphrey
(1977)
using
similar 2
LDV
measurement 2
2
techniques.
The
2
a , 2uu U , U , U ,u Z at ueur, xz uy, ~'y a r' wcost of the stations x/h - +0.25, +2.5. Water was employed as the fluid medium ac a number was 4.0 x i04Reynolds the and m/s 1.00 of bulk average velocity quantities recorded were U,
The
experiment
has
Ul Uz, Ua, Ur
clearly
been
carried
out
with
considerable
accuracy atnd detail and the data are well tabulated in a convenient "
Test Case. thin,
However,
attention
form for use as a
the boundary layers at the inlet to the bend were (deliberately)
b.Ang only 15% of the h~draulic diameter.
The ratio of shear-layer thickness to
radius of curvature in the bend is therefore much less than for Humphrey's (1977)
*The suggestion by F. Ges3ner to use A. Melling's nizing Committee; see Specification.
flow
data has been adopted by the Orga-
142
......................................
to
*-*.
.
•.°_ -.
"
_I in
which
the
secondary and, use
in
inlet
flow
and
view o'
as a Test
conditions its
effects
were will
nearly be much
fully less
this and the fact that Humphrey's Case,
as an additional
it
is
concluded
Test Case in
developed. in
the
The
experiment
data are considered
that the Taylor
the class of flows.
et al.
strength
of
the
et
al.
satisfactory
for
of
Taylor
data will not be
Specifications
required
of zomputations have
therefore not been presented.
REFERENCES Cebeci, T., and P. Bradshaw (1977). Momentum Transfer in Boundary Layers, Publishing Corporation, McGraw Hill Book Co., New York. Durst, F., A. Melling. and J. H. Whitelaw (1976). Doppler Anemometry, Academic Press, New York.
Principles and Practice
Gessner, F. B., J. K. Po, and A. F. Emery (1979). "Measurements turbulent flow in a square duct," Turbulent Shear FLows (edited by Springer-Verlag, New York. Humphrey,
J.
A.
C.
(1977).
'Flow
in
ducts
with
curvature
and
Hemisphere
of Laser-
of developing Durst et al.),
roughness,"
Ph.D.
thesis, University of London. Melling, A. (1975). "Investigation of flow in non-circular ducts and other configurations by laser-Doppler anemometry," Ph.D. thesis, University of London.
F.-
Prandtl,
L.
Shabaka,
"Turbulent I. M. M. A. (1979). thesis, University of London.
"Ph.D.
(1952).
Essentials of Fluid Dynamics, flow
Blackle, in
an
London.
idealised
Taylor, A. M. K. P., J. H. Whitelaw, and M. Yianueskio (1980). nar and turbulent flow in a curved duct with thin inlet Contract Rep. NASW-3258.
wing-body
junction,"
"Measurements of lamiboundary layers," NASA
Uy
IDEAI.ISED WING-BODY JUNCTION
I(SHABAKA, Figur.ý I.
1979)
Secondary flow of the first
2
W
kind due to a body in
143
contact with a surface.
-
DC
tn II
00C
c'o
00
C)
L
-
-
I AI CI-4
00 00
00
C)n
144J
DISCUSSION Flow 0510 flows considered here are discussed separately.
The two very different
Concerning the idealized wing-body junction, there was some feeling that computations should begin upstream of the to capture
methods managed of
computational
effort
would
unwise
be
the vortex several
to
lines
(as
distinct
be
view
was
that,
three-dimensional
elliptic
upstream
conditions
the wing can always
do
so.
wing.
also the
of
streamwise
however,
huge It
bending of
There was a
suspicion
In
the experiment)
distribution
There were,
length.
section
supervised
had the
from
test
the
the
Computors
inviscid
arabolic
2
further
calculation), the
of
of
because
the largely
prowess at handling
predictive
over
voiced
by
flow as presented by the eval-
to
responding
acknowledged
under-
suggestion,
this
that the
accumulation
little
was
vorticity)
the swirl
by
affected
that would
other aspects
of the measurementb
tegions where
the effective viscosities were
such as substantial
very challenging,
"negative:
saJority
On
the wing root.
pose a very severe test of turbulence models because
stresses.
Reynolds
at
fully
starting
prescribe
(who
Peter Bradshaw
formed
that the three-dimensional
decay
little
(a
required
around
discussers
uator would not went
the
the calculation
thereby testing how well
vortex
the horseshoe
possibility,
to demonstrate
wishing
A;-,
this
consideration
junction,
streamwise vorticity is not confined to a simple "vortex core" as
one might think. the
Concerning
36.8D (corresponding initial
provide the bend
however,
"turbulent stresses, that
the
to -8.25
conditions
was,
predictions
flow in
in
for
expected
there was
90' be-nd, this
agreement
tc be largely pressure
an expectation confirmed by J.A.C.
were
largely
Melling's data at
flow) be used as starting conditions in The
./nolds stresses.
all
that
independent
of
whether
mean
dominated Humphrey, or
not
order to
flew development
in
uninfluenced
by
and
who had obtained
turbulent
stresses
flow were
included. it
was recomiended
tations
be extended
liptic
computations
variations
in
into for
that the test-case specifications should prescribe that computhe straight laminar
section
flow
following the
(Taylor
pressure over the cross-section
145
et
al.,
900 bend, 1980)
since fully el-
suggest
remain at the 900 station.
that
strong
"SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/INCOMPRESSIBLE R.
Data Evaluator:
Case #0511;
I.
Data Taker:
Dean
B.
Shabaka
PiCIAl$ AL Sbip"'i f1.,
voal•oI gr4 A.
Date
0510.
i nnle io,SaanoTncy
'Ti
Do-
."mber
dp/'o or
Test all
'"Cami0
. QA 2
...
iat mn;_
Lind."
.L
1
.2
f:in|--
-•
of the rllrt
V or~
m:mmtr7p
DaaTae
V1m.
of staLtiO fSaorod4
voc#tt
thereL.Cf UI7nn
l
Other Not#.
CýI'
go
j..
.....
di.
b&ri.ed
:tr|le
lead '°- in a... no-e
Ca|l"lotions
t(the
.t.'~Ed
.
ohuu|4
-i be
dýownlre. .
Ingn
I ____"_____
1.s.1
:nont
____
________---_____
no..)
i
*d,. bo.
------
............
__________ ......
Comments
P. Plot
Ordinate
Abscissa
Range/Position
I
Cf
z
0 < z < 0.08 M
Tut
2l wall Cf at
x = 0.6858 m.
2
Cf
z
0 < z < 0.03 M
Tunnel wall Cf at
x = 1.2954 m.
3
Cf
y
0 < y < 0.08 m
Wing Cf at
x = 0.6858 m.
4
Cf
y
0 < y < 0.08 m
Wing Cf at
x
y
U/Ue
0 < y < 0.05 m
x - 0.6443 m, z ý 0.005025, 0.01003, 0.02337, 0.04338 m.
y
V/Ue
0 < y ( 0.05 m
x = 0.6443 m, z
S5
6
0.01003, W/Ue
7
y
8
y
-_uvU2
9
y
-2 -vw/U
e
1.2954 m.
0.02337,
-
0.005045, 0.04338 m.
0 < y e 0.05 m
x = 0.6443 m, z = 0.005025, 0.01003, 0.02337, 0.04338 m.
0 < y < 0.05 ru
x = C.6443 m,
0 < y < 0.05 a
x
0.01003, =
z = 0.005025,
0.02337,
0.04338 m.
0.6443 u), z = 0.005025, 0.02337, 0.04338 an.
0.01003, 10
y
U/Ue
0 < y < 0.05 m
0.-305025, x = 1.254 m, z 0.01003, 0.02337, 0.04338 a.
11
y
V/Ue
0 < y < 0.05 a
x = 1.254 m, z = 0.005025, 0.01003, 0.02337, 0.04338 a.
y
W/Ue
0 < y < 0.05 m
x = 1.254 m, r = 0.005025, 0.01003, 0.02337, 0.04338 m.
S12
ii14"
".
Comments
Abscissa
Range/Position
y
-2 -uv/U e
0 < y < 0.05 m
x - 1.254 m, z - 0.005025, 0.01003, 0.02337, 0.04338 m.
y
2
0 < y < 0.05 m
x - 1.254 m, z - 0.005025, 0.01003, 0.02337, 0.04338 m.
Plot
Ordinate
13
14
Special Instructions: It
is
low,
which
part
of
suggested is
the
that calculations
sufficiently wing.
Table
should be started at Station 2 of Table 1 be-
tar downstream of 1 gives
positions
the
recording data from static pressure taps, and cross-wires. line, but edge and
It
iq noted
the
in a
of all
pitot tubes,
that the wing is
the asymmetric effects
leading edge
offset
on the parallel-sided
meaurement
Preston tubes,
planes
used for
single hot wires
by 2" trom the tunnel center-
30"-wide tunnel will be small near the leading
insignificant farther downstream at Station 2.
This allows a one-dir0ensional
treatment of the pressure field outside the shear layer in two possible ways: is
outside the shear
layer
at
a
Use the measured p(x), given cross-section.
2.
Calculate p(x) one-dimensionally by treating half the tunnel crosa-section as a 0-,ct. The skew-induced secondary flow on the plane walls of the two-dimensional contraction is unlikely to cause any significant disturbance to the boundary It would therefore be sufficient to assume that layer on the 5"-high sidewalls. the displacement thickness everywhere on the tunnel walls is equal to that measured on the tunnel floor at the maximum distance from the wing.
Station No.
which
assumed constant
i.
Table 1 Axial Positions of McasurcmcnL Stations (Distances ate measured in mm relative to the wing leading edge) Cross-wire Single-wire Disc center (X-wire) (U-wire) Preston-tube Pitot-tube and staticmeasurement measurement measurement pressure measurement planes planes planes planes tappings
-9 -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 7 8 9
-1,295.4 -1,143.0 -990.6 -838.2 -685.8 -533.4 -381.0 -228.6 -76.2 76.2 228.6 381.0 533.4 685.8 838.2 990.6 1,143.0 1,295.4
-1,043.6
34.66 187.06 339.46 491.86 644.26
-738.8 -586.0 -434.0 -281.6 -129.2 23.2 175.6 328.0 480.4 632.8
949.06
937.6
1,253.86
1,242.4
-137.2 15.2 167.6 320.0 624.8
156.6
613.8
929.6 1,234.3
1,223.4
147
h
...
-"
- -
PLOT 1 CASE 0511 FILE 61 0.004
0
(1
0
0.002
00o)
0
0.000 00.02
0.04; z
(mn)
PLOT 2CASE 0.511 FILE G33 0.004
0 C
G
00
-
c.0000.02
z (ro)
. 29 54
PLOT 3 CASE 0511 FILE 61 0.004
C'
C
0.002
D.6858 a
0.000 0
0.04
0. 02
0.06
PLOT 4 CASEE 0511 FILE 63 0.004
0.000
0
0.02
)01 y
(Mn)
149
PLOT5 FL-TECAE 9094.9.12 011
0.015 t-:0J
0.010
7-T
o
i
0
0.10
0.0 52
0.000
1
0.23
.4
3
I
---
x
u
-0,6443m
PLOT 6 CASE 0511 FILES 90,94,98, 105 0.015kT-.
C5
C
o
.ý
0! 3
0.000
----
0
-0.5
0
-0.5 V'U* (xlO)
150
0
-0. 5 x
C 0.4-
A!
I
'i
.1
PLOT 7 CASE 0511 FILES 90.94.98.106 0.015 o-o-
0-010
...
-
0
0.
5 ,
I
-
0.005025 a
I
--
L
,
c
I-
'
10) ,
':0
:
--
L
a
-
00500.
I
0.5
-
-
0.. 5
0
0
--
-
0.1
-
0
D'
5'' 1
:iI
"%-
So -.
..
Ki
;"0.015
=.
0.6443 m
x-
PLOT 8 CASE 0511 FILES 90,94,98,106
•.:'.y
I
1
0.04338
0,02337
0.0100
""W/
--•€-,0.010
0
0
.
0
v
Sz
0.010 0.015
I:
T
~
-,
-,
-
=o-
005+
0
-
I
.1
-4
1511
•,.-...
:
. . .... ..- . . . 0.005.-0+0.,
.... ..
,
]
2
x
*
0.6443 rn.
1. 1
i.
. . .. ..-. .-.-.- . : .22:2 :: 2: .::: :.: .....:----.. -... . ...,-.
::2 : . : :
- :.:: . 2. : -: .. : - .:
. :: :2 ::151.
....
PLOT 9 CASE 0511 FILES 90,94,98,106
0.015 FT-,, i
' Si
0.010
C
oCo o I 0.010
-
L C'
-
0
'
0.005025
0
0.01003
0.001 0
0
T
'-
0
C
,0C
O C
0.02337
0.04338
0.001 0 -v- ."'L
1,001
0
0.001 - 0.6443 m
PLOT 10 CASE 0511 FILES 114.118,122,130 0.015o
.::
C
C
I
I
,
10
0.00
0C
C
05 -
-
-
-
-
0.000'
-
'
0.
0.
1
05 .I
05
,
.'-.,I.
~'
x 10)
152
,.-,
X -1.254
..-
m
I:PLOT
11 CASE 0511 FILES 1141,116,122,130
V=0
T
00
0
0.010
1-.
0.005
F
0
0
j
I
0000
I
.00000
-0.5
0
0.052
0.10
-0.5
I
~T1
0.23
0
-0.5
0.43
0 -0.5 (x10)
V/ U
0 -1.254
PLOT 12 CASE 0-511 FILES 114,118.122,130 0.015-
0
.0
0.1010
0.0105
O. )
~
----
0
0
.--
.052
05
0005.25
0
0
-
0 ,033
.000
05
0
0
j
0.4,3
0.
0
0
w/I3* (x10)
153
-1.4a
0.
PLOT 13 CASE 0511 FILES 114,113,122,130 0.015
F
-
0
-l
00
S.1 0 0
C
•
0.010
--
,--
'"•0
0
0
0
i
0"
0
1
i0
1
67,7
0
01.
-
1
C
254
PLOT 14 CASE 0511 FILES :14.118,122,130 0.010
I :°
00
•
-
-,,,,
0-,
•
00
.00
0~0010,
10i
0
£ -0.0525
.000
o
--
0
0" 3
.
154
001
0
QOl
154
t,-
'
:_
0.23
0
-v-: _ /U.2
IIII
o0
0
0
0.0
0
x-
01
1.254
=
-0-
..-
SPECIFTCATI0NS FO0R COMPUTATION ENTRY CASE/INC0MPRESSIBLE Case #0512;
Data Taker:
J. A. C. Humphrey
FICTIOIM. VlOe
0S1O. DOt. *.aklu1or-
Ce~ -Test
or
all Cwmeet-y
C,
C&. 051
Do...
1.
MOe
bet. Toter
R. B. Dean
Data Evaluator:
DOLAWRT
'%rh.Lant
I
Seconder,
uIuo
Fit..
of the
tlrot so.
rt o.l-
orU
IdZ
us
Ur
otl'r 0,2 .2no
1
a.
Otbot
ti0
N1ots
2 2~',.1rd
b~n4
Ot.rtd
1. 4oot
t
4.2 4"
o9dP.l
at..
lTS 7j
o.
1.0. 2YD
ZD
0 < YD < 1
Contours of U8/Ureft
-1.0 < ZD < 0
F3
YD
ZD
Contour values 1.28, 1.20,
0
Contours of Uu/uref at
-1.0 < ZD < 0 ZD
4YD
0 < YD < 1
YD
5
ZD0
-1.0-< ZD < 0
1.10
8
71.
Contour values 1.20, 1.10.
1.18, 1.15,
Contours of U,/U
at
6
=900.
ref....
--
-1.0 < ZD < 0
4
....
Contour values 1.25, 1.23, at Contours of U/U r ref
Contour
vi lues
1.20, 0
0
-0.55, -0.60,
-0.65, -0.75. YD
6
ZD
0 ( YD < 1 -1.0 < ZD < 0
7
8
Y
YD
ZD
0
YD
ZD
0 < YD < 1 -1.0 < ZD < 0
155
Contours of Ur/ure f at
Ed- g0oo
Contour values 0.28, 0.22, 0.12, -0.08. Contours of u u/U 2 at a ý 00 . o r ref Contour values 0.0005, 0, 0.001, 0.002. Contours of u0u r/U refat
0
=
Contour values -0.0005, 0.002, 0.003, 0.0045.
goo.
Special Instructions: test
This with a
90°
case
bend
considers
(Fig.
2).
the
flow in a
Water was
employed
as
the
of 0.89 m/s, and the Reynolds numnjer was
Svelocity
Calculation should be *
of
the
entrance
-
velocity Ux,
to
Uy,
the
started at bend
900
are
available
x/Dh -
at
0
-8.2,
of
square
fluid medium
4.0 x 10
At
at
cross-section a
bulk average
4 8.2 duct diameters upstream
i.e.,
0*.
-
duct
this
station,
profiles
of
mean
Uz and stresses uv,
-
rectangular
from the data bank,
uw,
u
~-2
V , W
,
together with details of the local pressure gradient
and skin friction. A plane
of
symmetry
along the
centerline of
the bend
assumed and predictions made for one-half of each plane at It
must
materially been
ad4usted
plane.
It
be
noted
affect to
remains
that
the
computations. satisfy an
the
additional There
are
upstream two
two-dimensional
open question,
at
0 -
0 = 00
of
which
to 900
0%, 450,
information
sets
continuity
present,
[rom
data
Melling's equation data set
71', of
data; in
the
may be
90
..
Melling
can
one
has
set
cross-flow
more closely
repre-
sents the true physical situation. YD and ZD are defined in
Fig.
2.
t-
i
*
A
156
-----
1
PLOT 1 CASE 0512 FILE 8 o 1.3 (U aUref1,
1.0
o 1.2 l 1.1 S1.0
=
)
YD
j
0.5
0.0
0
-0.5
-1
ZD PLOT 2 CASE 0.512 FILE 13 0 1.28 (Ue.,Uorr6 =45:)
1.0
1.2
'-
:Li
, 0.95
YD 0.5-
1Z
0.0 :
-1
D 0
-0.5
ZD
157
'
PLOT 3 CASE 0512 FILE 11-D~ 1.20 (Ue/Uet, 1-0 0
0
=7
1")1
.18
F 0 1.15
.
)~1.10
D.51
F.D
0D 0.
005
g,
1.5 1.01
L
.
0.01
-1
-0.5 ZDU
158
PLOT 5 CASE 0512 FILE 10 0 -0.55 (Ur/Uref ,6
1.0
=00)
o-0.60
YD 0.
0.5
-1-0.5
0
ZD PLOT 6 CASE 01512 FILE 19 0 0.28 (Ur/Uref 10L 1. * 0.22
0
90')
S0.12 't-0.08
YD 0.5 L
0.0 0
-1-0.5
ZD 159
PLOT 7 CASE 0512 FILE 12 130.0
1.0
2 (UOUr/'U ref, 80
0 0.05
)
YD
-1
0
-0.5 zD
PLOT 3 CASE 03512 FIT7 21 -0.0005(~''; 1. 0 .002
1.0
0.003 0.0045.4
)
9_
_
II 160
_
_
_
_
_
_
_
SESSION III
Chairman:
J. P. Johnston
Technical Recorders: A. Strawa I. P. Castro-
Flow 0250 Flow 0310 Flow 0150
161
I
II. THREE-DIMENSIONAL TURBULENT BOUNDARY LAYER
Flow 0250 Evaluators:
*t
D. A. Humphreys
and B. van den Berg
SUMMARY
Of
the
16
boundary-layer threc might in
cases
potentially
calculation
suitable
methods,
also be adopted,
four
cases
but
measurements,
not
cannot
be
three-dimensional
be recommended
Of the rest,
recommended
which could still
been demonstrated.
can
testing
turbulent
immediately.
A further
but with the rider that they are believed to be deficient
at least one essential respect.
test
for
at
either
present,
be performed,
All
some will undoubtedly prove useful as because
they
lack important
or because satisfactory flow quality has
16 of the cases are expected to provide information for
modeling the turbulence. INTRODUCTION The
report
dimensional
describes,
turbulent
in
condensed
boundary-layer
form,
the
experiments
results
made with the
which of them could serve to test calculation methods. limited in "
to cases
general
a
survey
of
three-
purpose of identifying
From the outset the survey was
which Reynolds stresses were measured.
This was because there is
no simple relation connecting the turbulence and the mean velocity
field in
boundary layers and calculations must allow for this.
[.
The
experimental
computer-digestible
*
expected.
It
was
results are
form.
being collected
Up to now,
decided
not
from their originators
13 cases have
to recommend
as
Table
.
-
I lists
all
label has been given and
the date of
The -
cases under evaluation. to each data set,
the earliest
work has taken
procedures
were
experimental
studied.
uncertainty
test
cases
at
this
Note that a six-character
made up from the names of
experiments
alphanumeric
the principal authors
major source publication.
two directions. This was
in
First,
order
to
the instrumentation extract
fundamental
but was also an attempt to understand which a new experiment being planned today.
of criteria
was drawn up and
applied to each case.
in
section.
The Aeronautical
stage
detail.
or should not be employed in
the next
and filed in
been received but three more are
where there has been no opportunity to examine the data in
*-
in
of
Some of
the main
Research Institute
tNational Aerospace Laboratory,
The
criteria
points to be noted
of Sweden,
Emmeloord,
Bromma,
and measurement
clues
relating to
techniques should Secondly,
arrived
a series
at are given
for each case are discussed
Sweden.
The Netherlands. 162
......................
•
"."".. ""
-
""4
•'
.
.*',,-
,
.
-
"
"
",
.-
"
".
in
the section
after
a.ad
relying
finally,
In suitability groups according
cases are put
however,
emphasized,
that
that
t'.e
opinions
on the
mostly
selection
expressed
be
should be
It
to all evidence to hand. here could
the
criteria,
if
modified
further
information becomes available. Cases Evaluated
TABLE 1.
First Major Publication
Test Case
Label
0251
BEEL72
van den Berg and Elsenaar (1972)
0252
BIME7Q BRTE69 COPA79
Bitsonnette (1970) Bradshaw and Terrell (1969) Pailhas (1979)
0253
DEFE77 EASA79 FEVA78 GRHI78 JOHN70 LAL071
Dechow (1977) East and Sawyer (1979) Fernholz and Vagt (1978) de Grande and Hirsch (1978) Johnston (1970) Larsson (1974)
0254
LOHM73 MUKR79 PIDU74 PIEZ75 SWGL78 ZI.KM7ý
Lohmann (1973) M6ller and Krause (1979) Pierce and Duerson (1974) Pierce and Ezekwe (1975) Swamy, Gowda, Lakshminath (1978) Zimmerman (1975)
EVALUATION CRITERIA An experiment may be viewed on three levels, of the particula:
acteristics
the whole flow in context,
realization and the detailed results.
possible test of calculition methods for three-dimensional
the char-
In its role as a the bound-
turbulent flow,
ary layer should be sufficiently three-dimeitsional, and adequately eventful in all aspects. For calculations to be possible and worth doing,
the experiment must provide
a full set of dynamic similarity parameters, closely spaced initial and boundary conditions, and enough additional results to vrify computations. conclusions
Before
it
experiment,
can
be
drawn
the
from
comparison
between
calculation
and
should be demonstrated for the experiment that flow symmetry assumptions are reasonable, the turbulence structure is normal, the momentum equations balance, and the measurements are reliable and compatible.
The onus is on the originators of an experiment to show that their results are of Where quantitative reliV')114rv and internal compatibility checks are good quality. 163
4-,
•-•'•-F-.-•-i!". i-"-.i--'i-. "'-'i'ii •,-i .7--..-.......-...-.-...-.......-"."..-...-..-..-"...".......,........."......
• -' .• -' . - '-\ - - -' . ' . - -
-
- . - .' - - -i .- °. " . "
. " - " . -V.'
.
. -'
" -"
.
- - . --. " -. - - .".
-..
.
'
.
""
it
possible but have not been done,
has been concluded that flow quality has not been
demonstrated.
REMARKS ON THE EXPERIMENTS Capp 0251 In test
pressure gradients were
(BEEL72)
surface.
Quasi-two-dimensional
conditions were
above the flat
suspended
by a body
induced
achieved
the
within
region of
influence of the initial line and the momentum balance has been shown to be good.
The
flow is long in terms of the initial boundary-layer thickness. Cases 0252/0254 Both
(BIME70)
dimensional)
(LOHM73)
are
realizations
case
the afterbody
but was
rotation rates,
though.
approximately
const.ant.
probably
been shown to hold except
Maximum cross-flow angle in layer relaxing
after
removal
(BRTE69),
measured.
is
gradient,
(1972).
Momentum balance extrapolate
the three-dimensional
This is
rotating about its axis.
Wall pressure was measured in The momentum equations
with
have
There are
a nominally quasi-two-dimensional is
only 80
in
the
boundary
test
region,
Agreement was not wholly satisfactory and
it was suggested that the external flow was not No compatibility checks have been carried out.
deficiency
is
(quasi-two-
An integral momentum balance has been carried out for
this case by Wheeler and Johnston
(COPA79)
axisymmetric
for internal compatibility checks.
of pressure
considered marginal.
unfortunate
the
at two of seven measurtng stations in (BIME70).
no "redundant" measurements in (BIME70)
which is
of
boundary layer on a cylinder whose afterbody
They differ in neither
and
this
important
sufficiently quasi-two-dimensional.
turbulent boundary layer of a lifting wing.
case
is
that
the
initial
line
turbulence
because transition occurred over a leading-edge
could be tested
but has not
been.
Reynolds
shear
was
bubble.
stresses do
simply to corresponding wall shear streses but may be compatible
An not
if
not due
allowance for pressure gradient is made. Case 0253 (see DEFE77) Two of the cases dimensional and ary layer
reviewed
fully three-dimensional
approaching
a
in
are nominally,
symmetrical
separate
boundary-layer
obstacle
on
a
regions,
flows.
flat
both quasi-two-
(DEFE77)
plate and
is the bound-
(PIEZ75)
is
the
boundary layer generated on a flat plate by a jet blowing against a perpendicular back wall. The most serious shortcoming of (DEFE77) is that no momentum balance has been done, nor would it in fact be very easy to do one, because of inconveniently located measuring stations. been determined.
However,
the data set does appear to be reliable as
far as has
The symmetry plane boundary layer can be calculated in isolation but
only one station is
available
to verify such calculations.
The case can be
treated
164
S . . . . . -.: . .. - .
-.-_ -:...
. .
: :
. .
..
.
..
.
:
:
. :
:
also as the
a
fully
three-dimensional
other
hand:
suffers
levels
of
very high
compatibility
.. f
(EASA79), reproduces in
turbulence
flow
against
(JOHN70)
in
as
initial to
in
a
for
swept
450
layers.
too
It
sparsely
having
been
completed.
experiment. (JOHNT0),
In
flow,
on a
balences
field and
and internal
and the are
that (EASA79)
short,
regard less
them it
been
very
nearly
was
the performance
originators
very
has not
plate,
the
than
shown
by
Humphreys
(1980)
but
experi-
about
six
would be necessary
demonstrated
the
-et
of a new
satisfactorily
No momentum balances have been carried out for (EASA79).
as
on
are puzzling differencco'
however,
order to calculate which
(PIEZ75),
pressure
flat
but there
stated,
Both cases
thicknetses.
defined
to investigate
probe)
lines.
for (PIEZ75).
respects,
but
side
Momentum
mounted
must be
film
free
flow.
step
a test case
assume quasi-two-dimensional
have
a
the external
(double-split
buundary-layer
for either
from
flow-defining
to provide
technique not
all
boundary
up not principally
ment
principally
layer with
results have not been demonstrated
the resulting
measuring
boundary
results
were
not
They
entirely
convincing. (FEVA78) mounted
is
the boundary
back plate.
enough
to
strictly
do be
layer
flowing along a circular
Momentum balances have not been done but
so.
flow
rhe
treated
as
is
such
not
in
conditions
the whole
boundary
not much scope
this stage of
a
swept
useful
on
the
because these
curved duct,
all
practice,
but
is
specified
for various
experiments.
(LAL074)
flat
plate
test cases,
of
as
no
(GkHI78)
incidence.
although
the small
varies
is
complete
and
little
cannot in
the
that by supplying
ini-
by
the
degree,
so
that
Influence there
(LAL074)
and
(SWGL78)
is
are
data have been received yet
is
All
it
This means
the boundary
on a model ship hull measured at
principle
a skew-
Principle, apparently
subsequent calculations.
(GRHI78),
reasons
in
demanded
to a high
to arise in
evaluation
unfortunately
region.
inflow boundaries
layer
for differences
Comments
nators
along
the data set
quasi-two-dimensional
transverse direction over most of the test tial
cylinder against
three
are
in
layer
a wind tunnel,
believed
cross-flows
of
on the
to
(SWGL78)
held over at
from the origiflat
of a
and (SWGL78)
represent
make it
floor
on
potentially
marginal
in
the
present context. (MUKR79) mounting adverse
a
the
turbulence at
gradients
the
were
boundary
layer
strated.
wall
gradients
layer was
measured
three-dimensional
deflecting
pressure
boundary line
is
to one produced
boundary
side of
by a body
very strongly affected
shows
some
unusual
outer
edge
of
the
large
it
relatively should
have
Skin-friction
been
formed
suspended
by
a
features
large
layer
believed
investigated.
values obtained with a
as
a
and
by of
test
trip
as
flat
surface
result.
pressure
Momentum
a
and by the action
above the
only
that
on
region
transition
possibly
boundary is
layer
the measuring
the
surface.
and the
Pressures adverse
variation
balance
has not
•. -...
-.
+
.,.
+ -.
• .
-
-
+ -
. •-
. .'+ .,
through
-, -
.
the
been demon-
Preston tube and with a Clauser method
•___ .
were
pressure
165
.-
The
initial
+-•
'
____ __-
•'
I are
compatible but
cannot
easily be
compared with Reynolds
stresses
extrapolated
to
the wall because of the large pressure gradients. The
boundary layer on the
geometry is
floor of a duct
flat
different from (GRH178).
to be the earliest
attempt
(PIDU74)
to measure
the
intended as a test for calculation methods. dimensional define it
but the
pressure.
is The
and internal
was
but the
was carried out in 1968 and is
believed
Reynolds stress
tensor.
It
was not
The flow must be regarded aa fully three-
along one line only,
are unfortunately
insufficient
to
for calculations.
(ZIMM75)
features
results,
(PIDU74)
full
also provides
the
layer
on
a
swept
integral momentum equations
compatibility
which are
very
boundary
high
tests
and
within
the
cross-flow angle was 4-1/2o
have been
plate
acceptable
results.
The
turbulence
level
boundary-layer while
at most,
at
turbulence
constant
and reliability the
However,
outside
flow
has
the boundary layer
profiles
cross-stream differences
this case
nominally
shown to hold
showed
not understood.
downstream almost without change,
flat
are
are
convected
large.
As
the
should perhaps be seen as a disturbed
two-dimensional boundary layer. The four cases which best satisfy the criteria are (BEEL72), and is
(LO1473), felt,
which are,
can provide
respectively,
good
calculation methods.
test cases
Cases 0251, for
0252,
0253,
three-dimensional
(BIME70),
and 0254.
turbulent
Three more cases can probably be used
(DEFE77), These,
it
boundary-layer
too but they
appear
to
have limitations. The cases are (BRTE69) in which the cross-flow is rather small and the essential quasi-two-dimensional condition is in doubt. (FEVA78), which has to be treated as fully three-diemnsional, ation,
and (MUKR79),
which is
but which does not show very much transverse vari-
believed to have been adversely affected by the transi-
tion device. CONCLUSIONS A survey which
inLlude
of
all
known
Reynolds-stress
three-dimensional measurements,
turbulent
has
boundary-layer
indicated
that
at
experiments,
least
four exist
which should provide satisfactory tests of calculation methods, and that at least three more may be acceptable for this purpose but are thought to be defective in some way.
[Ed.: It is regretted that these ing. Dr. Humphreys is arranging boundaries to be presented at a are, however, in the Data Library
four test cases could not be used for the 1981 meetfor the results of predictions on three-dimensional forthcoming conference--IUTAM Berlin 1982. The data for Cases 0251, 0252, 0253, and 0254.] 166
.- -• .- ,. . .o . -. . .-- - ., -. . . .o .
..- .
-..° -. . . - . i, . o i . - - . .
-° .
i
- -
, . ,
•
REFERENCES "An experimental study of the development Bissonnettc, L. R. (1970). dimensional turbulent boundary layer under rapidly changing rate Dissertation, Princeton University.
of a threeof strain,"
"The response of a turbulent boundary layer Bradshaw, P., and M. G. Terrell (1969). on an 'infinite' swept wing to the sudden removal of pressure gradient," NPL Aero Report 1305. Ceschwindigkeit und Reynoldsscher Spannungstensor in der "'ittlere Dechow, R. (1977). drei-dimensionalen turbulenten Wandgrenzschicht vor einem stehenden Zylinder," Dissertation, University of Karlsruhe. "Three-dimensional and Ch. Hirsch (1978). de Grande, G., boundary layers," VUB-STR-8, Vrije University, BrUssel. East,
incompressible
"Measurements of the turbulence L. F., and W. G. Sawyer (1979). swept step using a douhle split-film probe," RAP, TR 76136.
turbulent
ahead of a 45'
"Meisu-&•znts in an axisymmetric Fernholz, H. H., and J.-D. Vagt (1978). tiuong three-dimensional disturbances," boundary layer with weak and and Mechanisms of TuLbuience, Vol. I, Berlin, pp. 222-234.
turbulent Structure
"Terms in the equations of motion for Johnston's step flow," Humphreys, D. A. (1980). Tech. Note AU-1379, Berhkningsbesked 1 (to apAero. Res. Inst. Sweden (FFA), pear). "Measurements in a three-dimensional turbulent boundary layer Johnston, J. P. (1970). induced by a swept forward-facing step," J. Fluid Mech., 42:4, 823-844. An experimental investigaPart II. "Boundary layers of ships. Lareson, L. (1974). tion of the turbulent boundary layer on a ship model," Swedish State Shipbuilding Experimental Tank (SSPA), Report No. 46. "The response of a developed turulent boundary layer to local Lohmann, R. P. (1973). transverse surface motion," Dissertation, University of Connecticut. "Measurements of mean velocities and Reynolds and E. Krause (1979). MUller, U., stresses in an incompressible three-dimensional turbulent boundary layer," 2nd Symp. Turbulent Shear Flows, Imperial College, London, pp. 15.36-15.41. Champ "Couche limite et sillage turbulents tridimensionnels. Pailhas, G. (1979). moyen--Tensions de Reynolds," Diss. Conservatoire National des Arts et Mdtiers, Centre Rdgional Associ6 de Toulouse. "Measurements of the Reynolds stress ternsor Pierce, F. J., and S. H. Duerson (1974). in a three-dimensional turbulent boundary layer," Virginia Polytech. Inst. and State University, VPI-E-74-4. "Turbulent stress tensors in a threePolytech. Inst. and State University, VPI-
Pierce, F. J., and C. I. Ezekwe (1975). dimensional boundary layer," Virginia E-75-l. Swamy,
N. V. Ch., B. H. L. Gowda, and V. R. Lakshminath (1978). ments in the three-dimensional boundary layer on a yawed dence," Z. F~Ijwiss. Weltraumforsch., 2:1, 15-22.
"Turbulence measureflat plate at inci-
167
.
.
'•- - -- .
-. .
. "..
.".-.. •.-
. -..-.. --.... .-.
..
.-.-..
.
..
_. .
. .
.
-. .-..
.
.
.....-. i..
i
_ --_ ,
._ •
van den Berg, B., and A. Elsenaar (1972). "Measurements in a three-dimensional incompressible turbulent boundary layer in an adverse pressure gradient under infinite swept wing coneitions,- NLR TR 72092 U (draft). Wheeler, A. J., and J. P. Johnston (1972). "Three-dimensional turbulent boundary layers--Data sets for two-space coordinate flows," Thermosci. Div., Dept. of Mech. Eng., Stanford University, Rep. KD-32. Zi.."ewan, 0. R. (1975). -An experimental investigation of a three-dimensional turbulept boundary layer," Dissertation, Purdue University.
DISCUSSION Flow 0250 1.
The
evening
discussion
concentrated
on the
adequacy
of
the few
cases and on the selection criteria and their application. tion criteria, parties, able,
in daytime discussions
between
suggested
test
With regard to selec-
the Chairman and other interested
the point was made that a number of other excellent data sets are avail-
although they do not contain turbulence measurements and therefore did not
meet the evaluators'
selection criteria.
In the evening discussion,
the consen-
sus was that these criteria were reasonable for the purposes of the 1981 meeting, although they might not be for a specialist meeting on this topic. 2.
There was
some disagreement over whether flows in which reversals of cross-flow
direction
occur should be
included
as
test cases
and whether such
flows would
require a respecification of the necessary side boundary conditions. tors felt that no respecification is in
any case,
no suitable
required for such cases.
data set satisfying
The evalua-
However,
the selected
criteria,
there is, so
it
was
two-
or
agreed that these disagreements were not currently important. 3.
Pierce
commented
that
three-dimensional
some
log-like
doubt laws
remains to
infer
about
the validity
wall-shear
stress
of in
using strongly
three-
dimensional flows. 4.
There was much discussion about ularly
in
three-dimensional
independent suggested cases. inal
evaluation flows
were
about really
the
made,
being quoted,
adequacy
possible
general flows i.!
Perry
they
of
those
the
should
that
evaluators
estimates.
redundant
measurements,
partic-
both
felt
that,
in the turbulence
data
for the four
not
Muller
automatically
be
unless
included
as
test
in addition to the error estimates of the orig-
to verify uncertainty
agreement
and
of the uncertainties
Johnston suggested that, authors
the accuracy of hot-wire
flows.
should The
evaluators
estimates of
measurements
their role as accuracy checks,
and,
make some
are
in
personal
noted
that
the originators. especially
particular,
useful
judgments it
is
not
There was ti
these
van den Berg stated
that he relied on them as much as on the standard momentum balance checks. 168
-.
"
".'.
.
.
-
A
.
i
-
.
5.
Joubert
expressed
the opinion
that unless hot wirer are calibrated dynamically,
any measurements made in regions where total turbulence about
10% should
be
questioned.
Also,
where
possible,
intensity (q'/Q) exceeds redundant
measurements
should be obtained in a given apparatus with two different classes of initrument, e.g.,
hot-wire and LDV.
The evalu&tors comment
emphasize the need for redundant del
d.
the Chairman notes that
ject.
for example,
calibration
in a
that,
similar turbulent
that
their criteria
In regard to the question of dynamic hot-
wire calibration, Some feel,
(see above)
as
there are other opinions on this sublong as q'/Q does not exceed 25 to 30%,
flow with known characteristics
developed pipe flow) should suffice.
A.
169
(e.g.,
fully
PLANAR MIXING
LAYER
Flow 0310
Case 0311 Evaluator:
S.
Birch
SUMMARY
SELECTION
CRITERIA AND FLOWS SELECTED
The
reported
incompressible, rccent that
layers
spreading
earlier
spreading
mixing
rate,
if
been
was
due
to
an
reviewer's
estimate
given approximately
and
the
U2
are
for the
nominally major
fully
source
developed,
of
however,
concern
in
..-
to conclude
(within the uncertainty of the data) sufficiently of
the
high
and that
sensitivity
of
much
mixing
spreading rate
limit,
persists
indefinitely,
practice;
for
but
practical
the
on
the high
in
and
purposes,
spreading
low velocity
between
the
sides of
points
at
the two streams become equal,
the zero spreading local
fully developed
mix-
. 0.115 U1 -+uU2 U1+U2 1
as the velocities
Since,
of a
by
the velocities
formed.
in
a
underestimate
and L is the width defined to be the distance and 0.949(Ul - U2) + U2 0-316(UI - U2 ) + U2 In
a
data available,
the Reynolds number is
dL
U1
has
of
and boundary condition.
present
ing layer is
where
layer
rate
layer does reach a unique
confusion
to initial
The
the
There now appears to be sufficient
an isolated mixing
the
in
single-stream
years.
asymptotic of
variation
the
velocity
defect
rate predicted
rate
does
on
by Eq.
approach
zero
wake
is
with
layer
U equals
a planar wake is
the (1)
the
which
centerltne
not achievable
increasing
down-
stream distance. The generally by (where
spreading quoted U0
0
rate of
in U
e
terms
the approximately of
the
self-similar
velocity half-width
region
of
and
given
Y1/2
is
a planar
wake
is
approximately
UC)
CL U
e U
dY __/2_ U dxi/2 dx
0.098
(2)
0
Since in
the
far wake
Uo (< Ue
,
we can rewrite
this
in
a form equivalent
to Eq.
(1) as I dL ),
=
0.242
dx
2U
c dL dx
U
(3)
0
Boeing Military Airplane Go.,
P.
0. Box 3999,
Seattle,
WA
98124.
170
.S..
.
. 1"
. . .
. . . .
.
.
•2 i-1"' '-i-] -i.1--i.-'-. '-]." .-i i'.i.
.
'-i
2 -" - 1 ' 2 'i'- '-
.[
.
' - i
" -"
"
"
.
2 " i • 2 . .- I
.
-"i .'-
-4
where
X is
defincd as e UCL U 10 U "UU -U + U
X a
e Comparing
this with Eq.
e
UCL
centerline
velocity
(4)
CL
we see that the spreading rate of the half-wake
(1),
is
almost
twice that of a mixing layer.
purposes
one would
turbulence
flow with
well-defined
initial
measurements--particularly
shear-stress
measurements--to
main features extend the
of
accuracy
tial
fully
and
starting
The data should
developed
consistency
Until we have a
conditions,
latter
a
the flow.
into the
cluded.
like
of
the
of
data
conditions
cover the complete
the
flow,
unless
better understanding
a fully
condition
region
of
since it
the
a
laminar
boundary
of
is
to region
assess is
in-
the flow to iniprobably a
the
tha
region and
difficult
developed
layer
because
BuffLýer't
characterize
the sensitivity of
layer,
and
developing is
fully
developed turbulent wall boundary
than
For calculation
less well understood.
regon of a mixing layer is
Tle developing
sensitivity
better of
the
flow to external disturbances. No
totally
satisfactory
be available at present. lent wall boundary
in
Fig.
by
the
the above criteria
are listed in
Hussain,
1979).
Table
all
i (Gartshore,
corresponding
momentum
The spreading
rate
at
appears
to
developing from turbu-
1965; Foss,
1977; and
two
The normalized data for these flows are plotted
All four sets of data appear to collapse to a single curve
1.
point.
all
Four single-stream mixing layers,
layers,
flows from Husain and
data set that satisfies
thickness
of
the farthest
the
boundary
layer
downstream station
dhen normalized
at
the
separation
appears to be close to
the asymptotic value. The axisymmetric nozzle
diameters
mixing-layer data e-tend downstream
where
transverse curvature
effects,
however,
velocity
spreading rate
to
justify a
number;
but
appear
conclusion the
plot
to
lead
curve. that
does
to
no
noticeable
the normalized that
of about four
effects are no longer negligible.
The variation in
suggest
to a distance
change
in
th'I
shape
of the
Rea for these four flows is
data are
Reynolds
totally
number
independent
effects
are
These mean
too small
of Reynolds
probably
fairly
small. ADVICE FOR FUTURE DATA TAKERS The unique most the *.
to
planar
mixing
to this flow,
important
separation
a
fully
poses
a
number
are at least particularly
of these
resulting difficulty obtain
layer
is in
developed
probably
flow
in
difficultie3
tr-ublesome in
the persistent
achieving a
point should be laminar.
of
that,
effects of
the minimum distance,
not
completely
this flow geometry.
truly self-similar flow.
A low value of Re, is
if
initial If
The
conditions
and
the objective
is
the boundary
layer
at
the
probably also helpful.
171
. .
-7-
-4
As an estim~ire of the distance rec~uired fo' a single-stream flow to becorne fui'.y developed, Bradshaw's (1966) suggestion of 7 X the most useful.
This distance
10o5 v/ul or 1000 0 still appears to 'oe
increases with velocity ratio; but,
for
Iwo stream
mixing layers, there appears to be a b~ronger dependence on the detailled initial conditions.
Tripping the boundary layer before the separation point will typically ex-
tend the development distance by at least a factor of two. Although the best data from planar mixing-layer studies agree very w!11 with data from the quasi-planar region in the near field of nxisytmmetric jets, the incidences of anomalous or apparently anomalous behavior are encountered more frequently in planar mixing-layer studies.
This suggests that particular care shou~ld be taken when using
this ilow geometry.
-~
REFERENCES Bradshaw, P. (1966N. "The effoct of initial conditions on the development of a free shear layer," J. Fluid Mech., 26, Part 2, 225-236. Foss, J. F. (1977). "The effect of the laiainar/turbulent boundary layer states on the development of a plane mix~r.g layer," ?ro.ý. Symposium on Turbulent Shear Flows, April 18-20, pp. 11.33-11.42. *
Gartshore, 1. S. (1965). "The streamwise development of two-dimensional wall jets and other two-dimensional turbulent shear flows," Ph.D. Thesis, McGill University, Mont real. Husain, Z. D., and Hussain, A. K. M. F. (1979). "Axisymmetric Mixing Layer: influence of the initial and boundary conditions," AIAA Jou., 17(1), 48-55. TABLE I Summary of Data in Mixing-Layer (Fig. 1) Author
Vel., in/sec
0i
Re Rax 10Comments
cm
Gartshore (1965)
19.6
0.079
1.04
Piano mixing layer
Fob3 (1977)
18.3
0.081
1.07
Plane -nixing,layer with end end plate
*Husain
and hussain (1979)
30.0
0.0706
1.45
12.7-ca diam. nozzle without end plate
*Husain *(1979)
and Hussain
30.0
0.0632
1.29
12. 7 -cm Jiam. nozzle with end plaise
All flows are developing from nominally fully developed wall bouiidary layers. 04
momentum thicKness of wAll bc~undaL-y layer it the separAtion point.
L
tidth w
of
which
U
mixing =
Layer:
VO.9 Uand
def ined
as
Y/OIU
Asymptotic spreading rate approx.
0.115.
172
the
distance between the
points
at
z z
LLC.wZ 0
00 >1
El
Ele
LL
CM
Ga~~~U
to
m
C
8.
~ 'HII ~ ~NXV 91-1 3Y 170
ts
D
-4D
.
DI SCUSSION Flow 0310 I.. The major point to emerge from the discussion, vin,
was
that
"example, noted ary
R.
layers and
computors
influence
Luxton
that a
marks,
the
pointed
simple
of out
initial that
conditions sound
distinction between
is
not
sufficient.
S.
it
was
,;ecided
the
to warrant
a
that
was
affected
"laminar"
Birch
at
flow,
agreed
For
clenr.
and
I.
Wygnanskt
initial
with
sufficient
(see Ad-Hoc
by M. Mocko-
all
and "turbulent"
was of
discussion
not
the
essentially
problem
tw-re extended
which was initiated
bound-
all
these
importance
Committee
re-
to the
report
No.
3). 2.
There
were
two
later
during
winor
the
points or
day,
query from W. Reynolds, boundary
"1
layer
in elliptic
(in
raised
at
S.
the
evening
Birch confirmed
a single-stream
calculations
mathematics may rn.•
be,
which
thic
of
mixing flow
were
clarified
committee that
whilst
0 was P.
the
floor
meeting.
his
layer).
in
in
that of
Saffman
physics
are
discussion,
response
to
a
the separating
pointed out
that
posed,
well
the
unless the outlet boundary conditions are properly speci-
fied. 3.
Finally, width,
S.
Birch disagreed with I.
which
the latter
W-gnanski over his definition of mixing-layer
felt concealed much of the scatter in
the published data.
After the 1980 meeting the following comments were received from A. Hussain: A.
Asymptotic it
mixing layer:
conclusively
Only in
demonstrated
the expeciment
of
Hussain and Kleis
(1980)
that a universal plane mixing layer does exist,
is both
with laminar and fully developed turbulent exit boundary layers. B.
Region 1000
of
0,
self-preservation:
the value
evaluator. .
0.11.
In
initial
of R0 ,
dL/dx
is
found
to exceed
mixing
boundary
layer
it
was
is
0.115,
the value of dL/dx obtained
an axisymmetric
"initially laminar the
of
However,
Since self-preservation
the value
by Hussain
found
that
layer and 0.139 for an initially
boundary layer was laminar,
only
attained
x >
suggested by the
and Kleis
(1980)
dL/dx - 0.116 turbulent
the shear-layer evolution was
but noticeably dependent on the initial
at
was
for an
flow.
When
independent
fluctuation level and its
spectral
content.
.c C.
Dependence the
on the end-plate:
single-3tream
free mixing
It
has been found by Husain and Hussain
layer
is
independent
of
the presence
(1979)
that
or otherwise
of an end-plate. D.
Initial namely
shear-stress U(y),
to Lhe finite
u
2
(y),
measurement: and
@u"
The inltt..
Measurements
of
lateral extent of hot-wire or LDV
conditions that are meaningftl are v2
and UT1 present difficulties
due
instrumentation.
174
.
..
I
E.
ubln
nicopesbefe
odtos
inta
Rl
of
flo
are a unique function of the ini'_ial conditions.
flows it has been The3e are classified as
turbulent. F.
Aaiý,)priate produced
tripa:
In most previous experimental studies trip wires have rarely turbulent
ftilly developed
flow at exit.
is
Experience of this author
that effective trips should be piaced 100 6 upstream of lip, have a height equal to
the
displacement
thickness,
spanwise notches spaced a displacement
ar~d have
thickness apart. G.
Initial tant
fluctu~tion:
because of its
layer.
influence on the
instability of an initially laminar shear
An initially fully turbulent boundazy layer has strong fluctuations and
is uninfluenced -
The spectral content of the initial fluctuations is impor-
by the
typical low-level
free-stream fluctuations.
However,
a
fully turbulent shear layer may itself become unstable and roll, up further down-
.
stream (Clark and Hussain, 1979).
=
H.
Any invasive measurementn of the initial shear layer
Distortion by
shear tone:
almost always
induce a shear tone
(Hussain~ and Zaman, 1978), and this leads
misleading data on initial conditiona.
[Ed.:
This is a summary of much longer
discussion notes submitted by Dr. A. 'C.M. F. Hussain. are
important with
respect
to
data on mixing
Although these comments
layers it is not considered
require the specification for Case 0311 to be modified.]
175
...................................................
to
.7
they
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case 00311; Data Taker:
Data Evaluator: Four sets;
S. Birch
see specification
PICTORIAL SL49WY Plow aPRagar 0)0. Ortd inateter: oito S.bitsh.
r
I
Pat.Uke Cý
,
i II
t
.1e . 1~o -t
Wt
W
Cynr.s
Other ton•
h,
*otas
0311
Cas
ilnltiol developeent
Wta embll4 ff"
_
_
_
i
_
L
_
I
_____
x/i
of then
O<x/ei < at
For single-stream mixing layer, continue to fully developed condition, but at least x/0i = 2000.
1 ist 2000
Special Instruction: 1.
0i - momentum thickness at separation point.
2.
Take Re
3.
Report asymptotic spreading rate dL/dx found for Plot I as a number.
4.
Experimental data
as 1210.
component initial
of
the
station.
(Husain and Hus3aln, turbulence Other
are
1979)
p:ovided
quantities
needed
for the mean velocity and the axial for to
obtained by assuoing that the boundary layer is
the start
wall
boundary
the
layer
calculation
fully developed.
at
should
the be
All quantities
used to start the calculation should be reported. Special Symbols L
width for a mixing layer between the point at which
U
-
U2
is
A. I(U 1 - U2 )
and 4.9(U1 - U2 ) high-speed ide of a mixing layer; the on U- value of U U2 - value of U on the lhw-speed side of a mixing layer; x - downstream distance; y -
cross-stream distance; U - U A- 1 2, U + U 1 27176
-_V6
4
PLOT 1 CASE 0311 FILES 3,4,5,6 200L
150
[
FOSS
0
GARTSHORE
0
L/e
1
j
c>
D
HUSSAIN 1
-
HUSSAIN 2 0I
100
50
0 I
X/
177
I
TWO-DIMENSIONAL CHANNEL FLOW WITH PERIODIC PERTURBATIONS Flow 0150
Cases 0151,
0152
M. Acharya*
Evaluator:
SUMMARY
fully
and
or axisymmetric)
(planar
be two-dimensional
flow should
turbulent
The
1.
the selection of test cases:
were used in
The following criteria
developed. 2.
The imposed periodic disturbance should not cause
3.
Measurements
of
4
as well as amplitude-
phase-
include
should
quantities
periodic
flow separation.
information. stress field are desirable.
ments of the perturbation
4.
Measui
5.
Data should
and enough infor-
of accuracy and repeatability,
satisfy requirements
'-I
mation snould be available to serve as a basis for computations. the following two cases were selected.
Based on the foregoing,
4ussain-Reynolds Experiment (1970).
Case 0151. The
plane
Nearly
and
techniques
were
Most of half-width
Hz.
The
to
used
measure
ý
were
at
different for
documented
perturbation
introduced additional periodic velociinstrumentation
Hot-wire the
mean,
and
fluctuating,
and
conditional compo-
periodic
for a Reynolds number
four
transverse
the
the
frequencies,
oscillation and
in
locations
streamwise
stresses
Reynolds
of 13,800,
based on channel per-
The amplitudes and phases of the streamwise
centerline velocity.
velocity
disturbances
turbulent
the data were obtained
and
These
fluw.
test section with the help
the
in
velocity.
nents of the streamwise
turbation
which fully
in
air channel
high-aspect-ratio
a
driven ribbons. the
in
pressure
sampling
in
were introduced
wave disturbances
electromagnetically
ties
conducted
two-dimensional turbulent flow could be obtained.
developed
of
were
experiments
flow 25,
symmetric
for 75,
50,
perturbation
and
100
velocity
v
were not measured. The and
data
show
that
the
perturbation
decay almost exponentially
in
velocities
the streamwise
are
direction.
and wave length decreases with increasing frequency.
Brown,
Boveri Ltd.,
CH-5405 Baden-Datwil,
Switzerland. 178
small The
compared
to
the
mean,
decay rate increases
6.
Acharya--Reynolds Experiment (1975).
Case 0152. The
were
experiments
Reynolds,
conducted
in
same
flow channel
used
periodic
oscillations
in
the
produce controlled
to
modified
The perturbation velocity had a slug-flow character, developing
with a Stokes layer
instrumentation
hot-wire
Reynolds,
also obtained
perturbation
flow,
the case of Hussain and
in
were uned to
techniques
sampling
a Reynolds number of 13,800
for
In
These data
based on channel half-width and
The amplitudes and phases of the perturbation velocities and the
centerline velocity. Reynolds
stresses
oscillation frequency of 24 Hz, Hz.
As
the mean and perturbation Reynolds stresses were also measured.
addition,
section.
ccnctant over most of the
the wall regions. and conditicnal
test
and periodic components of the streamwise velocity.
fluctuating,
measure the mean,
were
in
and
by Hussain
the
were
two
for
measured
at
amplitudes
oscillation
an
amplitude at 40
and for one (the higher) oscillation
Only data for the higher oscillation amplitude are reported here. The
uncertainty estimates
quantities
other
than
the
gave
on
5% on magnitude and 40
perturbation
Reynolds
strebses,
phase for moot 10% and
which were
flow 150,
respectively. There
Other comments: flows;
is
a lack of data of this kind It
more experiments would be welcome.
is
for unsteady
turbulent
recommended that future measurements
also include data on higher harmonics. REFERENCES "Measurements and predictions of a fully and W. C. Reynolds (1975). Acharya, M., developed turbulent channel flow with imposed controlled oscillations," Tech. Rept. TF-8, Thermosciences Div., Dept. of Mech. Eng., Stenford University. Hussain, A. K. M. F., and W. C. Reynolds wave in turbulent shear flow," Tech. Mech. Eng., Stanford University.
..
.
•
*
-
"-i~ - .. '.- -'-.' -.
"The mechanics of a perturbation (1970). Rept. FM-6, Thermosciences Div., Dept. of
- .' ': -. .- '.
.-
"-
"
-
..-.-
_
179
" .'- - " - .S . ' .:
--.
- .
-. "--.. -- -. - .
".
2
-
-.
-. .
.-..i
- ' '
'-
DISCUSSION Flow 0150 The discussfua
of
this
flow was
flavored
by the fact that the general
unsteady flows will be discussed in Session XII by L.
Carr.-
In response to queries ty A. Smlts and A. Perry, the two experiments evaluated the only significant waveforms was the turbulence and is
topic of
W. Rey,.olds pointed out that in
source of "Jitter" on the velocity
therefore part of the problem to be solved by the
predictors. There was some discussion concerning the presence of higher harmonics in the data which resulted in a final consensus that these were not important, low amplitude compares view of the
latcer
either using a full, linearized equations
to the
fact,
it
fundamental,
which was
since they were of
itself of small amplitude.
In
was also agreed that compucors would have the option of
time-dependent
method or a method based on the small-amplitude,
for the ensemble-averaged
results.
Several discussers mentioned other flows that should have been considered in this class.
For example,
B. Ramaprian mentioned his own high-amplitude perturbations of a
pipe flow and two other similar experiments. feeling was that
sideration as test cases, the
data
and,
In the evening discussion,
the general
the evaluated cases are important enough to be recommended
second,
a
for con-
but first an independent evaluator should be asked to review third
test
case
of
the
should be evaluated and included as a test case if
high-amplitude,
pipe-flow
variety
possible.
B. Ramaprian expressed the opinion that the recommended data sets were not suitable as test cases because the modulation amplitude (1% and 4% of mean :low speed) was too
small
ness.
to enable
This
most predictive
opinion was
not
schemes
unanimously
to distinguish the effects
held by all
people
present
at
of unsteadithe evening
discussion.
(Ed.: The participants at this conference concluded that Flow 0150 should be dithdrawn as a test case for 1981 since there are acvantages in treating unsteady flows as a separate class from the majority of steidy flows treated in the 1981 Conference. This
recommendation
has
been
carried
out.
Library.] 180
However,
the
data
remain
in
the
Data
.i
SESSI0I! IV
Chairman: W. C. Reynolds (for W. M. Kays)
Technical Re~corders: A. Cutler A. K. M. F. Hussain
Flow
QUO0
Flow 0130 Numerical Ch~ecks
G. Hellor F. Gessner
181
CORNER FLOW (SECONDARY
ILOW OF THE SECOND KIND)
Flow 0110 Cases 0111, 0112 Evaluator:
F.
B.
Gessner
SUMMARY
INTRODUCTION This
report
summarizes
along a streamwise stress gradients all,
the
corner in
acting in
results
of
a
which secondary
data
flows are
the corner region
1979) ity
The
in
results of
flow
by virtue of Reynolds-
flow of the
second kind).
this nurvey are presented
in
a preliminary report
predictions.
The data sets considered
in
In
(Gessner,
Turbulent flow in
constant-area rectangular ducts
2.
Turbulent flow in
other constant-area,
3.
Transitional
4.
Zero- and variable-pressure (interior)
gradient
turbulent
corner
flows
5.
Zeroand variable-pressure (exterior)
gradient
turbulent
corner
flows
6.
Turbulent corner flows with heat transfer.
Categories
1. 2,
purposes,
marginally
recommended
and
while
attention
rectangular
constant-area,
6,
several
those
acceptable.
that
constant-area
flow in
in
In be
data
the
confined
ducts)
summary shall concentrate
for
the
non-circular ducts
sets
the to
sur-
non-circular ducts
other
reviewing
that
namely:
I.
comparison
this
turbulent
and approximately seventy of these were
vey were categorized within six major categories,
only
to
which various data sets are rated with respect to both accuracy and suitabil-
for comparison with numerical
In
related
induced
(secondary
over ninety sources of data were located,
surveyed.
survey
were
rated as
categories report,
data
the
sets
purposes
of
were
either
Organizing
within
this
being
suitable
for
unsuitable
or
Committee
Category
conference.
on data sets which have been selected
1
(flow
has in
Accordingly,
for inclusion
in
the final report.
SELECTED DATA SETS Ten part or
data in
sets
total)
developed
flow
Brundrett
(1963);
*Mech.
Engr.
in
in
Category
I
on
smooth-wall
for comparison with numerical a
smooth-walled,
and
Dept.,
Launder
and
square Ying
are
results.
duct:
(1971).
University of Washington,
ducts
Hoagland
regarded
WA
suitable
Four of
these concern
(1960);
Leutheusser
Six concern
Seattle,
as
developing
(in
fully
(1961);
flow in
the
98195.
"182
•ik .''..''.-
.'
.
-..-
-
-
..- "
.
.
. . .-
-
. -
.
--. -
- -. .
...
.~-. - L----
- -.
--.- .. :
-.
.-
-.
.. i
-
S
.,
•.
-.
,..
.
-.
•.
.
. .. .
.,
o.
.-
same
geometric
J
configuration:
the moot comprehensive number
to
minimize
encompass
set
mean
flow
is
It
was
that
local
the
levels
flow
those
reported
and
Emery
(1979).
In
in
Po
All
given test (for
in
(1975),
desirable r 3ion;
that
the
the
data
shear-layer-
and at a location where
should
terms of primary-
et al.
also
provide
a
fairly
and secondary-flow velocity
symmetric about
Lund
(1977),
results
are
corner and wall bisectors
data
sets
which meet
and Gessner
based
et al.
these
(1979),
on measurements
in
for all criteria
and Gessner
the
same
experi-
x 10 5. each
4
the potential core of a free jet before and after measurements
I
in
measurements
order
data-reduction
the purpose of
data
only available
hot-wire
3tation
the tangential
in
cooling factur in
four
each set
for that
studies,
also calibrated
of measurements
particular wire (again,
the duct).
I
value of the mean bridge
wire probe was
before and after
data taken
these
the intercept
Each inclined
pipe-flow
reducing hot-wire
reported
to determine
purposes).
turbulent
order to determine
considered
The
Gessner
predictions with
distributions, and Reynolds-stress distributions. that inlet flow conditions should be well posed and
The
these
the
fully developed,
(1977);
flow ýat a given Reynolds
near-entrance
at a bulk Reynolds number of 2.5
performing
voltage
the flow in
esqential
by
was
the
developed.
be relatively
probe was calibrated at a
of
development.
are
mental facility
fully
wall-shear-stress
flow should
of
Lund
for square-duct
it
zones:
(1975);
to compare numerical
thL wall boundary layers have merged;
nominally
also considered
Po
order
costs),
three
complete characterization profiles,
In
of data available
in
region after
(1975);
(1979).
computational
measurements
interaction the
Melling
and Gessner and Emery
(1979);
Details
in for
of the calibration
procedures are described by Po (1975). The consistency of the Reynolds stress measurements was investigated by comparing distributioas of u2, v 2 , w 2 , and -UV measured by
various
investigators
along
the
corner
and
wall
along the plane
of symmetry of high-aspect-ratio
obtained
(1975)
(1974)
by
at
exhibit check,
both
other
a
may
et al.
the
consistent
Reynolds
numbers
decrease
refer
to
(1979)
which provide
the
the
by Po.
profiles
measurements
by
Lund
careful
an
increase
or
more
by
Gessner
data
± 0.050
by this
are
sets
for
confirmation
of
each
J1979)
each
profile)
(1975)
and
J
of
and Dean
As
a
further
balances
reported
by
the overall
accuracy
of
gradiant)
I
stress component
number.
data selected
Emery
duct
and
Reynolds-st
-ss
for comparison purposes
which
are
using
a
based
on
multiple
relatively
accurate
(Flow angles in low-intensity flows can be determined
technique).
considered
calibration
and
square
by Melling
Reynolds
(mean-velocity
a
was found that the results
values
in
of
transport-equation
indirect
profile
It
reported
normalized
The secondary-flow-velocity reported
(two
(1977)
that
dacts.
those
Reynolds-stress
single-wire rotation technique. to within
with
in
with
primary-flow-velocity
measurements are
are
consistent
one
Gessner
Po
bisectors
to
and measurement
be
The
local wall-shear-stress
suitable
for
comparison
techniques employed.
measurements
purpoocs
(Measurementp
because
of
nia-le the
were made with
183
h
- ...
.k.
-,".., .. ..
... .
..
..
.
..
",*
.-
-,,..
4.
.;
..
.
.
.
.
..........
;
:
.
".
-,4
thr~e different-diameter in
fully
and
developed
turbulent
more recent data
described observed
near-wall
flow).
The
obtained by Eppich
The above duct.
more fully,
0110).
(1980) order
data
data reported
the
by Lund
to provide additional summarized
based
on
calibrated
same calibration
the
in
the
(1977)
techniques
information on
"Specification
results
and Gessner and Emery (1979)
selected
data
In
to explore
order
wall
Hinze (1973)
constitute
wall
selectively
have
provided
are
all
the
also be
based
of
Po
(1975),
are presented in
predictive
data
set
the fully developed
roughened.
More recent data
measurements
by
wall-roughness
on measurements
considered.
an acceptabi:
additional
data
sets
capabilities
Committec has recommended that
conditions
surements were made in
turbulence
in
using
the probes were
for Lund
the final
1980).
smooth-rough
different
near-wall
results are
Tabulated
the Organizing
The
These
et al. (1979),
report (Gessner,
walls.
pipe
behavior.
(Flow
Gesener
square
tubes at etch point after
above have also been analyzed
Comp'.•tations" (1977),
Preston
on
flow
Fujita
are included,
flow in
in
square
which
a particular
purpose.
ducts
with
flow
smooth, limits
smooth-walled,
in
three
duct with one
and Humphrey
duct
rough,
the comparisons
(1977)
roughened
square
walls
by
that study mea-
artificially a
code
data generated In
a 5:1 aspect-ratio
primary
wall
a
a duct with combined
studies by Fujita (1978)
(one
however,
of
experimental
for this
region of
include
conditions
The
in
with
six
etc.).
No
that can be made
with this data set. The data of tions
in
Humphrey
the entrance
(1977)
m of equally spaced, however, ingly complex, state-of-the-art. relatively
markedly
given
streamwj.se
vary in
the
from
that
stitute
because
flow
in
location,
the
the
a
it
reasonably
in
selection
tency ments. about
in
of
this
data
particular
the measurements Lines
of constant
the midplane and,
lent shear-stress
and
at
a
in
above
for
data
set
is
that
axial mean velocity
in
the
Furthermore,
ribs at
a
law-of-the-wall must behavior
Gessner (1980). data of
Hinze (1973)
con-
combined
JusLified was in
of symmetry,
plane of
also on
exercised
in
performing
occasions are in
"
.
.
consis-
the experisymmetric and turbu-
good agreement.
symmetry appear to be accurate,
". "
of
are
transverse mean-velocity
184
S.-
the basis
the duct cross-section
profiles measured on three separate
The dissipation-rate
adjacent
velocity-profile
that only the a
the
exceedpresent
the duct width is
between
rib.
in
near-wall
to
by
smooth-rough wall duct flow based on currently available turbulence models.
care
on the plane
either
which appear
to note
data
the
relative
more detail in
set
distribu-
selectively roughened
cross-section
order to model
which can be compared with predictions The
rib height
cross-section
will suffice
complete
the
coefficients
direction
with one wall
This particular flow situation is amenable to analysis within the
structure
These points are discussed
For the present,
duct
transverse ribs. and not believed
local
the spanwise
properly.
a square
For example,
large,
varies
include both mean-flow and Reynolds-stress
region of
inasmuch as
profiles based
on assumed
tion.
The
overall
stant
axial
mean
{eynoldG-streas, are
erployed
available
in
isotropy at three dJfferent levels follow a common distribuare available for this test case include lines of convelocity in the duct cross-section, and complete mean-velocity, data which
and
in
dissipation-rate
the
"Specification8
Cessner
data
in
the
plane
for Comnutations,
of
symmetry.
Case 0112."
These
Tabulated
results data
are
(1980).*
ADVICE FOR FUTURE DATA TAKERS The
afore-mentioned
developing
turbulent
duct with
selectively
a
relatively
the probe ments in are
short,
in
flow in
slant-wire
order to prescribe This set
the over-all hot-wire shear-stress a further 2
data
check
÷
a
square
probe
duct and In
acquiring
(200
measurements
in
<
< Z/d
reasonably developed data
in
400),
the
I
can also serve
system.
Analysis
near-wall
measurements,
-I/U*
a
fully
complete flow
in
these types
it is
pictuce
of
a rectangular of flow with
advisable
to calibrate
turbulent pipe flow before and after each set of measure-
anemometer
the
provide
a proper value for the tangential
of
taken
on
studies
roughened walls.
fully developed
reduced.
(
selected
should
that
still
a
exist
a check on
the
accuracy
of
of local wall-shear and turbulent-
region oi
in
as
cooling factor when data
a
smooth
duct
well-defined in
the
can
also
constant
presence
serve
stress
of weak
as
layer
to moderate
secondary flows. The
need
presently
more
stringent
data
referred
locally
in
referred wall
Lest to
exists
the corner region
in
additional
ducts
with
corner-flow
predictive
adverse-piessure-gradient
to the near-wall
data
for
of three-dimensional
but remains attached
various
types
of
wall
flow
condltio-.s
would
the
effects
the
isolated
from
predictions
*[Ed.:
the
elsewhere.
the
influence
of
the
of
roughness be
specif'sd wall
for
In
when
a
include global detached dati
particular,
This
turbulence
functions
provide
flow is
zero,
desirable.
prescribed
can
More comprehensive
structure of the flow are also needed.
particularly
if
which
These data
flow conditions when
adverse-pressure-gradient important
data
codes.
near-
favorable,
and
information model
are
comparisons
to
is be
between
and measurements are made.
These data have been put on tape and are
see paper on Data Library by B.
J.
Cantwell.1
185
.. ccessible
in
machine-readable
form;
I
REFERENCES APB N_•
"Experiments on hydrudy.ia,Beavers, G. S., E. M. Sparrow, and R. A. Magnuson (1970). ically developing flow in rectangular duccs of arbitrary aspect ratio," 1JHMT, 13, 689-702. "The production and diffusion of vorticity in channel flow," BrundretL, E. (1963). University of Toronto (see also J. Report UT Mech E TP6302, Mech. Eng. Dept., Fluid Mach., 19, Part 3, 375-394, 1964). "An experimental investigation of shear Dean, R. B. (1974). ducts and diffusers," Ph.D. Thesis, University of London.
layer
interaction
in
"The numerical prediction of Emery, A. F., P. K. Neighbors, and F. B. Sessner (1980). developing turbulent flow and heat transfer in a square duct, J. Heat Transfer, Trans. ASME, 102, 51"57. "Development of a prcssure-strain model for Lurbulent fl.ow Eppich, H. M. (1980). along a streamwis2 corner," M.S. Thesis, Mech. En?. Dept., University of Washington (in preparation). "Turbulert LJOws in Fujita, H. (1978). wall planes," Research Report of the sity, pp. 11-15.
squaie ducts consisting of snooth and rough 3, Mie UIniverFacult of Engineering. Vol.
"Corner flow dat.. evaluation," Gessner, F. B. (1979>. Dept., University of Washington. "Corner flow data evaluation," Gessner, F. B. (1980). University of Washington.
Preliminary Report,
Final Report,
Mech.
Xech.
Eng.
Eng.
Dept.,
"Measurements of developing turbuGessner, F. B., J. K. Po, and A. F. Emery (197q). eds., ., lent flow in a square duct," Turbulent She3r Flows, Vol. I, F. Durst Springer-Verlag, New York, pp. 119-136.
-
"The numerical prediction of developing turGessner, F. B., and A. F. Emery (1979). bulent flow in rectangular ducts," Svmposium on Turbulent Shear Flows, Vol. 111, Imperial College, London, pp. 17.1-17.6. "Measurement of laminar flow development in Goldstein, R. I., and D. K. Kreid (1967). a square duzt using a laser-Doppler flowmeter," ASME, J. Appl. Mech, 34, 813-818.
__
-Experimental investigations on secondary currents in the t'r'uHinze, J. 0. ('_97L). lent flow through a straight conduit," Report WTIrD 27, Laboratory for Aero- acid ,;73Delft University of Technology (also available as NBS No. Hydrodynamics, 14279). "Experimental investigation on secondary currents Hinze, J. 0. (1973). lent flow through a straight conduit," Appl. Sci. Res., 28, 453-465. flow in "Fully dei-loped turbulent L. C. (i960). Hoagland, ducts--secondary flow, its cause and effect on the primary Mech. Eng. Dept.. ,.i.I.T.
in
the turbu-
straight rectangular f'ow,' Ph.D. Thesis,
h. "Flow In ducts with curvature and roughness," J. A. C. (1977). Humphrey, Shear Flows, London (see also Svymosium en Turbulent University of Thesis, Vol. I1 , Imperial College, London, 1979, pp. 17,7-17.12).
-
.
...-.
&-.-"."
-
~
-
.
..
'
-
"Fully developed tur!hule.ot flow in ducts of l~aunder. B. E., and W. M1.Y ing (L971). square cross section,'* Report TM/TN/A/1l, Mech. En~g. Dept. , Imperial College of Scienceo and Technology, Lonidon (ace also J3. Fluid 1ý'ch.-, 54, Parz 2, 289-295,
1972').1 "I'le effect of cross-section geometry upon th.e resistance Leuth'±usser, H. J, (1961). to flow in conduits," Ph.D. Thesis. Mech. Eng. Dept., University of Toronto (see also J. ASCE, Hydraulics Div., 89(11Y3), 1-19, 1963). Lund,
E. G. (1977).
"Mean
flow
and turbulence
characteristics
in the
near corner
region of a square duct," M.S. Thesis, Mech. E~ng. Dccpt., University of Washington. "Investigation of flow in non-circular ducts and other configura-j M elling, A. (1975). tions by laser Doppler anemometry," Ph.D. Thesis, University of London (see also 2. Fluid Mech., 78, Pact 2, 289-315, 1976). Po,
J. K. (1975).
"Developing
turbulent
flow
in the entrance
duct," M.S. Thesis, Mech. Eng. Dept., University of Washington.
187
*
region of
~i
square
~ .
DISCUSSION
FLOW 0110 1.
The
main
was whether
flow specifications
the
criticism ot
it
was
for
desirable
Empir-
conditions to bc specified along the first mesh line adjacent to the wall.
ical wall functions were to be given to do this, which involved changing the wallfunction constants from those applicable to the flat-plate boundary luyer. 2.
than having
.uany
engineering
point
points very close to
grid
extended
to be
were
of
more
view,
if
the case in
3
in computing time
particularly
the wall,
flows, argument
counter
The
useful.
the method
if
from the
and so, was
a
if
that,
the ýomputation should start at the wall itself;
a modified law of the wall and wall
first mesh line adjaceot
was more economical
of three-dimensional
to other types
method is to be truly predictive, and
that it
for this approach was
The argment
to the wall,
functions are required
to get
to the
such relationships should iot he specific to
hand.
The consensus was
that F.
GeE.sner's wall-function ccnstants
-nay be used by com-
putore as a guide but cannot sDecifically be used in an algorithm unless the algorithm uses the same constants from case to case. 4.
It
was suggested by D. Wilcox that use of a syst-matic perturbation analysis upon
the flat-plate wall function might be used to get around this problem, tion arose ac to how k shoild be regarded,
and
computors
ar.
whether as a true turbulence kinetic
velocity scale used merely as a calculation con-
energy or simply as a turbulen;-' venience,
The ques-
asked
to say
how
they
regard
k if
they
use a
k-c
mode..
-A
-<.4
--
(Ed.:
Gessae'
<.9
has modified the specificrtion to veflect this recommendation.] i8L
t•_.-.&.,,% - ,..-.
.-...
,.
. ... ,.,,,.....
..-..-
..
.. . --..
..
.
,-
...... .
.
-A . .. .
..
,.
*. .
.
. .
. ,
. .
-
-. ....
-.
-
.- -.
SP'ECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRIESbIBLE Case #0111l;
Dar- Evaluator:
Data Takers:
Flo.w 0110.
-
-
Date 9vak..co.,
J. Po (and others)
PILTOILA.SLU4AJ1Y G-ad..o 'Career fl~o (Sscon..ry plo.,
p.
T
1
-
r of
________
L--
41,/dR cafe
V 1
Test Kim
Cae akr
1
o- try
w I
,
ra... 0111I. 1.
riessoo
it
StationsMeasured-_
u,,
V
1
7. notOhe.1 Padc
Cf
I" io'~ of K
I
ordinate
Abscissa
Range/Position
1
C
x/D
0 < x/Dh < 90
< AID( 9 O0 h0.06,
LUbxD.
___
-.
Plot
2U/bXD 2
it the Se~oad Kind).'
rhrb.,Iance Profile$
I
un -,*
I
F. B. Gesstier
i
t.
oa
O
ther Ifiats a ot~
C
(bse 1.4 'eo-t dat ..1 wboik f 1100lo. 1dod. 90In.1-11,
Comments Axial static pressure distribution 4 curves at 0.10.
y/a as0.02, 0.04,
90
4 curver. at 0.6, 1.6.
y/a
3
U/Ub
x/Dh
0
11
U/1.b
fl/Dh
0 < x/Dh
90
4 curves at 0.06, 0.10.
y'Ia' as0.02, 0.04,
5
1U/Ub
X/Dh
0 < x/D, <9 0
4 curves at 0.6, 1.0.
y'/a' as0.2, 0.4,
6
V/Ub
y/a
0 < yla < 1
2 curves at
x/Dh -40,
84.
7
V'/N b
y f/a f
0 < Y'/a' < 1
2 curves at
x/Dh
84.
8
T/T/ I//
9
y/a
z/a
A/Dh
Wall shear stress poieat X/Dh = 84.
0
5 contours for
x/D h y/a
Z/a
-40,
0 < y/ 1 ya__pofl
0 za 10.8,
10
0.2, 0.4,
-
8
U/U
0.85, 0.9, 0A9. See comment 4b; use of symmetry along corneir bisector permissible.
0 K y/a < 1
5 contours for
0 K z/a < 1
0.8, 0.85, 0.9, 0.95.
xDh -16L i89
-0.7,
U/Un
0.7,
7
Comments
Plot
Ordinate
Abscissa
Range/Position
11
y/a
z/a
0 < y/a < 1
5 contours for
0 < z/a < 1
0.8, 0.85, 0.9, 0.95.
x/Dh 12
z/a
y/a
y/a
z/a
24 U/Uc = 0.7,
0 < y/a < 1
5 contours for
0 < z/a < 1
0.8, 0.85, 0.9, 0.95.
x/Dh 13
-
U/Uc - 0.7,
-
40
0 < y/a .< 1
5 contours for
0 < z/a < 1
0.8, 0.85,
U/Uc = 0.7,
0.9, 0.95.
x/Dh = 84
14
y/a
z/a
0 < y/a < 1
6 contours for -:v/Ub = 2, 4, 6, 8, 12, 16 (all x 10 4).
0 < z/a < 1 x/Dh - 24
15
y/a
z/a
0 < y/a <1
7 contours for
0 < z/a < 1
30,
40,
50,
K/Ub2 = 10, 20,
60,
4 70 (all x 10 ).
x/Dh - 24 16
y/a
z/a
0 < y/a < 1
7 contours for
0 < z/a < 1
4, 6, 8, 12,
x/Dh
17
18
y/a
z/a
y/a
z/a
=
-uv/Ub
= 2,
20 (all x 104).
16,
40
0 < y/a <1
7 contours for
0 < z/a < 1
40,
x/Dh - 40 0< y/a (1
10 contours for
0 < z/a < 1
-2,
50,
K/U
60, 70,
=
20, 30,
80 (all x 10 4). -v/U2
= -3,
-u/b
19
y/a
z/a
-1, 0, 2,
4, 6,
8,
12,
16
=
20,
30,
(all x 10).4
h = 84 0< y/a <(1
6 contours for
0 < z/a < 1
4 40, 50, 60, 70 (all x 10 ).
x/Dh
=
K/U2
84
Special Instructions:
I. For notation see Fig. 1 below. 2.
Note that two coordinates are used.
General Features This
test
case
is
concerned with
turbulent
flow in
a constant-area
square duct
which develops ideally from a zero-turbulence level, uniform mean flow at the duct inlet (U - Ub,
V - W
=
0),
as shown in
190
Fig.
I.
The bulk Reynolds number may be
regarded ment at
dkvclopmenL
of
cells
two secondary-flow
the corner bisector
(the dashed-line
a
formed
,4pond
to
components
flow pattern (V and
flow.
mean
W) which formation
The acting
gradients
boundary-layer
in
the
by
can be
corner
in
each
in
the
regauded
is
ce;,.l
not
are
present
mean-velocity
upon the primary
of Reynolds-stress
result
the direct
which
region
transverse
the
about
These cells corre-
1).
superimposed
as being
centered
which are
Fig.
vector sum of
the streamwine
in
two-&.1wensional
flows.
Optional Laminar Flow Predictions
3.
ded
that
tions.
Two
profiles
measured
Goldstein
sets
data
and
for
suitable
et al.
by Beavers
Kreid
(1967)
data obtained
be made with
comparisons
initial
predictive code,
of nn appropriate
the development
order to aid
In
flow
1. Axial static
a
in
flow condi-
static-pressure measured
square
duct.
(ordinate) (abscissa)
U /UI (x/Dh)/Reb
(ordinate) (abscissa)
1 cm - 0.5 1 cm - 5 x 10-3
0 to 6 0 to 8 x 10-2 i to 2.2 0 to 18 x 10-
1 Cm - 0.1 1 cm M I x 10-2
Axial centerline velocity distribution
3.
Wall bisector velocity profilest
UN/U y/a
(ordinate) (abscissa)
0.4 to 2.4 0 to 1
1 cm 1 cm
4.
Corner bisector velocity profiles
U/Ub y'/a'
(ordinate) (abscissa)
0.1. to 2.4 0 to 1
1 cm - 0.2 1 cm = 0.1
(x/Dh
"(x/Dh tional
order 0) 84), times.
to compute
local
flow development the
0-15 (fully
mean
from an is
flow
nominally
a
location
where
it
is
expedient
to use empirical wall functions
For
two-dimensional
predictive
are to be made with profiles developcd flow).
codes
optional;
measured
~191...
at
uniform state
initially
to
The compiitaLton of the laminar case is
itComparsons
•.,.".
0.2 0.1
-
Specification of Boundary Conditions In
r,• .:
2
Flow Predictions
Turbulent a.
These
Scale
2.
..
by
sl'ould be
plots
Range
C (x/Dh3/Reb
recom:mea-
is
prof!les
Separate
1980).
it
laminar
axial
include
laminna
Variables
Plot
uuder
and mean-velocity
,1970)
devL oping
for
purpose
this
data are available in tabulated forva (Gessner, ielow: made in accordance with the listings
i'-[:
quadrant
distributions
these
of
flow is
A unique feature of thi'
(x/Dh - 0).
inlet
the duct
develop-
boundary-layer
to initiate turbulent
high
being sufficiently
as
fully
developed
to minimize computa-
.Th employ
the K-t model,
plots are not supplied.]
(x/Dh)/Reb
0.0075,
0.020,
and
i-I
-
the
following
conditions
to a bounding wall
are often
specified
along
the
first
mesh
line
adjacent
"amely yU,
U
Xn y
K
flows.
Kl,
In
Lurbulent
C,
the past, flow
4K
in
a
square
(z
-
the wall
of
this
data,
first
section
K/U2
(3) 1
duct
mesh
is
and
K
E
for two-dimensional
KI
some computors have made K-c type predictions of developing
the
and
(2)
and Cw are prescribed constants with
plane along y)
1
2
U* K,
(1)
K
U
where
C
+
line
bisector to
Ey/U*
by
note
(say,
(z
y
- a)
that
vary in
applying -
Eqs.
(l)-(3)
constant)
at
in
between
each streamwise
although
Eq.
the near-wall
(1)
a given
the corner
location.
is
fitted
so
that Eqs.
region,
transverse
well
bisector
The purpose by near-wall
(2)
and
(3)
do
not appear to be satisfied when CP and KI are prescribed as constants. At where
the Reynolds number of
the
mean
Lund (1977)
flow
is
nominally
show that Eq.
(1)
lies between 40 and 200 (0.01 500
(0.04
though same
ý y/a
profiles
overall
consistent when
< 0.1),
the
in
region,
dissipation
in
a
is
x 105)
good K
In
modeled
all
data
locatior,
obtained
z-locations
within
provided that y+
5.2),
a good
wake-like by
that apparent equating
it
approximation,
behavior. Eppich
(1980)
variations to
the
These variations are nummarized in
in
al-
Within
this
show
that
Ey/Uv
exist
turbulence kinetic-
the table below:
ZIG Variable -2 2--)
-l 3)
y/a
y
0.02
0.05
0.10
0.20
0.60
1.00
0.02 0.05
1 100 250
0.081 -
0.075
0.069
0.066
0.059
0.051
0.095
0.10
500
-
-
0.090 0.115
0.073 0.106
0.068 0.084
0.058 0.064
0.02
100
0.40
0.31
0.34
0.37
0.41
0.41
0.31
0.32
0.31
0.38
0.37
0.43
0.37
0.40
0.39
0.05
-
250
-
0.10
-
500
-
-
192
by
the y+ interval between 200 and
measurements
by
at
still
is
slight
8&),
-
C -
and
0.40
-
law-of-the-wall exhibit
(x/Dh
approximation
y/a K 0.04).
recent
and at a streamwise
developed
KU2 occur and
rate
rate.
g
(2.5
fully
(with
region
however,
variations
energy production
the
this
is
1.0
0.01 < z/a <
the inter.al
interest
The
Reb -
crease
values
given
V.
trends exhibited by the (K/U2)
ent when in
1.2
x 105 (Eppich,
between
z-location
values in
1980),
the above table are also pres-
which lends support to the observed de-
the corner and wall bisectors
as the wall
is
approached.
when y is
The observed
fixed,
or at a
spanwise variations
in
3 -1 at a given y-location also exist at this lower Reynolds number. (cy/U*)On for C
the and
basis in
K,
of
based on constant and
experiment
this model zero
on
is
(2)
the
(3)
of
region than
transverse
(y/a
symdetry
appears
be
b.
at
x/Dh
Flow in
and
corner
an Octant: ,
1
-
-
(y
the primary
present
measurements,
include
secondary-flow
various streamwise
- zl,
isocontours
secondary flow field in it
in:
(i)
16,
24);
velocity
a
the K-c model and
K,
z/a
-
1) without
U
to
in
U,
is
region where (1i) peaks
in
the
(x/Dh
of IM in
recommended
velocity
plots
Ub,
improperly itself.
c may be set
V
If
equal to
reservation.
W
and
-0,
K
The -c
are
vectors
in
nominally fully developed
the region field.
0 < y/a
the
plotted
the
of
and
(x/Dh -
from the
predicted
octant
z/a < 1
information on
not available
plotting in
0 <
1,
Although global
flow region is
that
<
of
the
(1980)
results flow
at
show that
each octant.]
intended
shear-layer 40);
by virtue of image reflection about
[The computations of Emery et al.
to compare predicted
the wall boundary
-
yl)
the developing
locations.
isocontour
z -
shear-stress
only a single cell should develop The
values
predictions
Pints 9 through 22
z,)
bisector,
completely define the
If
0.
Because u-5y Sthe
constant
primarily
of
proper starting conditions consists of letting 0
due
deficiencies
I
prescribed
discrepancies between predictions
may
gradients
-
that
accord with reality.
and K, are made,
rather
employed,
it
are not in
near-wall
functions,
lines
results,
and
values of C in
speciiied wall
these
Eqs.
layers
interaction (iii) 84).
193
at
a
and measured
have not yet merged
region where location
the
where
axial the
results
(x/Dh
-
8,
hA
centerline
mean
flow
is
"Li
_
V
aa
Duct Dimensions a -
u,
12.7 cm (5.000
(x/Dh)max -
v,
w
-
in.)
nents in
84
x-,
y-,
z-directions, U, V, W
Operating Conditions Ub -
fluctuating velocity compo-
15.2 ups (50.0
respectively
wean velocity components m x-,
fps)
and
y-,
and z-directions,
respectively
Reb - 2.5 x 105
Ub -
bulk velocity
Uc - axial centerline velocity
7
Symbol Definitions
U* -
friction velocity
-
V
a
V' -
mean velocity component
in
a'
duct half width diagonal half width (a'
-
-
r2 a)
y'-direction
Cp - pressure coefficient
(C9
Y, y, PU))
diameter (Dh
2a)
P(O)
-
= diagonal
y+
-
-
pressure at
E
x - 0
-
coordinates
coordinate
dimensionless coordinate (y+
pressure
mean static
z - cartesian
y'
turbulence kinetic energy
P - mean static
Rcb
- P]/(1/2
duct hydraulic
DhK -
[P(0)
(U,
- yU,/v)
dissipation rate
v - kinematic
viscosity
bulk Reynolds number
p -
(Reb
1w -
local wall shear stress
Tw
spanwise averaged value of Tw
UbDh/V)
Figure 1.
Duct dimensions,
fluid density
operating conditions, Case 0111.
194
and symbol definitions,
in
PLOT 1 CASE 0111 FILE 7 I
I
II
8 0
1.00
•
0.5
WALL A
/o 0.0
WALL B
0
0.0
40
20
0
x/Dh
80
60
PLOT 2 CASE 0111 FILE 8 I.
.
"
7/a " 0.02
I . I
|¶
j
I
.
.
I
I
0.10
0.06
0.04
"
-
1.0
0-
0ooocol
T, b
0
30
I
<' o
--
0.5 0
0 0 0
50
0
50
0
50 X5Dh
195
0
50
" " "
PLOT 3 CASE 0111 FILE 8
I
,
y/a
0.2
0.4
0.6
.1 ,'.
1.0
<>
1.2
0
U/Ub
00 0
b
0
1.0
o
0
o 0
0
50
OOO
00
0 0
0
0
<0
0
i~i-0.400 0 50
0
50
0
50
0
0.
50
'x /Dh
PLOT 4 CASE 0111 FILE 9 Yl ,I.
= 0.02
1
0.04
10.06
i
0.1.0
1.0°
0I
5050
0
5
X//•h U/U
£%•196
0
50
j
PLOT 5 CASE 0111 FILE 9
'"
7'/a'
-
"
I
"
' "
" I
.
.
.
I
.
.
. I
I
.
.
.
I
.
1.0
0.6
0.4
0.2
"
00
0
1.2 /0
0 0
00
0
0
1t0
00
0
0
0
8 #000
0
50
0
50
0
50 x/Dh
0
50
PLOT 6 CASE 0111 FILES 10,12 0.010
x/I
- 40-
0,0°01
Ih
0 0
0
0*000
880000 0
V/Ub
*00 0 0
0.005
8
0
000
8000 00 8
0 0
0
0
0
08 0 0
0
0
0
0.000
0 0
00
0 00•190
0 00
I
0.50.
I
I
.
PLOT 7 CASE 0111 FILES 11,12 x /D'
x/Dh
- 40
-
.84
0
0.00
0
8 0
8o
o
V'/Ub
0
b00 0
0 0
08
8o
-0.01
040
" 4,
O~0o 4
0.5
0
00 0
0
1
0.5
y'/a'
PLOT 8 CASE ,840111 FILE 1
-0.01
Tw
/
0
"W
'10 ,,-,
0..5.. o
Tw,.
l-
,9
0.5-.5
198
PLOT 9 CASE 0 111 FILE 14 1.0
y/a0.b
0.05
PLOT 10 CAE011FE1
0.51-3 0.95
oII_
_
0
0.51
yz/'
10.9
:1
PLOT I11 CASE 0111 FILE 16 2 hCDb
1.0
T/Uc
0.5
0.95
(
/
x/D
..
________
Ia
40.9
..-
y/a-0.95
0.80
0.70
200
PLOT 13 CASE 0 111 FILE 18 1.0
z/h-84'
y/a
TI/Uc L-0.93
1
0.51 0."0
K
-0.85
0.80 0.70
0.0!-
0.5
0
z/a
PLOT 14 CASE 0 111 FILE 19 1.0
Ah2
v,/a 0.3'-
L
16
-
0.0
z "a
201.
PLOT 15 CASE 0 111 FILES 20,21 1.01
K/Dh -24
y/a0.
z/aU
PLOT ~
~
~IE 16CS111 ~ 22 b:
1.0
2
40
60
0
0.5 zi a
202
PLOT 17 CASE 0111 FILES 924,25 rID?; x14
y/a
2
30
0.5
40
60
0.04 0
0.51 z //a
PLOT 18 CASE 0111 FILES 26,27 4
1.0
Y/
~-
0I4m4.u/~1
6
0.5
*4
12
0.0
1 0
0.51 z/a
203
PLOT 19 CASE 0111 FILE 208 1.0
X/D
84
1oj
1
20
P3
y/a
/
/'
30
70
0.0
-
0
0.51
204
GPICIFkICATIO'S F'OR COPLUTATION ~ENTRY CASe/INCOMPRESSIBLE
.•
Case YO112;
F.
Data E.valuator:
_
R. Gessner
J. Hinze
Data Taker:
FICTOURA SUIVARY no
oio
"•.rket' r riou (sotoodary rlo,
DoLa, o& vlkalCtorl P. aosmmnor.
I Cos.D
"---AS ge.Kk'
JPS.
los
4~
•.ZI
.reLee
PrahL
e
I.
__
I
Ordinate
Abscissa
1
y/a
Z/a
4
nIsWa
ot th, !,scoedKisd).ý
2
.m t roct
Plot
2
nbmbr of ItsttiO
oV.*
I'I
__
.
0 < z/
,_ -___"._
d
.
vlo..
A
Comments
Range/Position
< 2.45
U/Urlia-
5 contours for
0 _ y/a < 1
0.80,
U/Umax'o
0 < y/a < 1
z
yU*/v
U/U,
20 < yU*/v < 500 __ "--
z
0.85,
00; a -
-
U 1I/U /U* *
1500 30 __< UI,*/v __<
0.092 r..
0
ar-e
y/a
V/UmaxO
0 < y/a < 1
z
re defined
"-
l•.-"''' i .2b o Fi; on . 2 belol.
z -0
.
0.70,
0.90, 0.95.
y,y' Yl
yjUl,/V
0; UmaxO
-
14.4 m/s.
a ,o".": z
/U21/U0 _<.y/a < 1
5
y/a
6
yla
(v2)1/2/Umax o
7
y/a
(w2)l/
8
y/a
-ulumax,o
9
y/a
C (M2 /sec 3 )
2
It
Li
I
y/a
(.2)1l/2/
R tI d.....2L,,___
0 < y/a < I
0 < y/a <
/u
-
0.
-
0.
z " 0.
I
< 7/a < 1
z
0 < y/a < 1
z
'
"
-
0. D
Special Instructions:
1.
For notation, see Fig. 2 below; note use of two sets of coordinates.
2.
All data at
3.
Show on plot for value of U2,
x/Dh -
at
126.
calculated values of U, at ?UV/LJaxO y/a
-
y/a
-
0
ane calculated
1 205
.
. *
-.-
¶.,,
-. .-
1
°
_
5.
General Features This test provides data corresponding to flow in a constant-area rectangular duct The roughness elements
with a peripherally non-uniform wall-roughness condition.
were plastic grains having average roughness height of 0.004 m.
Other pertinent
data which define the duct configuration and opocationg conditions of this study are shown in 126,
where
x is
fully developed
from the duct entrance,
measured
the
fairly strong
giv,.!s rise to a
- 0)
(y
lower wall
he regarded as
The non-uniform wall
and independent of inlet flow conditions.
roughness condition along secondary
flow can
the
away. trom the wall near the plane of symmetry
flow directed
x/Dh
were made at
Inasmuch as all measurements
2 below.
Fig.
(z
-
0).
This transverse mean flow appears in the form of two secondary-flow cells in the 2) which dis-
central portion of the duct (the dashed line distributions in Fig.
of thin distortion,
the maximum velocity does not occur in the plane of symmetry,
but instead at the two locations shown in for
purposes
of compar,
include
)n
the
2.
Fig.
The data which are available of
variation
global
lines
of
constant
and mean flow and turbulence data along the plane of symme-
axial mean velocity, try.
As a result
as shown in the figure.
tort lines of constant axial mean velocity,
The data also include
local
friction
tubL in the plane of symmetry (U* - 0.56 m/s These dca', Yl - 0). (1971, *973).
are
reported and
velocities measured at
discussed
with a Preston
and Ui* - 0.69 m/s
y - 0
at
two publications by Hinze
in
"206
"
206
•.., ,.o •-,',.-.-,'.--.
.
... .* V. . ,.. . **-. ~ ...-* •,'.-e-tV-.- .'.---'-.-"-
.-
., . ... . . . -'-
. . - --. ---.-
.
i
*--.i.
.
.
.
.
-
o: - ---.
plane of symmetry
U/ mx
.
0.
+
Vj
/Une
z rough
c
C-
rough
Duct Dimensions
L
a - 0.092 m b - 0.225 m c - 0.05 m Operating Conditions 14.4' mps (maximum velocity in plane of symmetry)
-mx'
Uma
15.0 mps (maximum velocity in duct cross-section)
Remax
U1 *
U
-
1.5 x 10~
-*0.56wm/s at
y-O0
-0.69 m/s
y-
Figure 2.
Ilk
1)~/v
aL
0
Details of duct configuration and operating conditions, Case 0112.
207
PLOT 1 CASE 0112 FILE 2
0.55
00.9 yz/a 0.9 0.5
0.80
0.80
0.00 0
0.09
2
00
m
0
0.5
208
000
PLOT 3 CASE 0112 FILE 3 p
p
0
- 0
03z
0 0
yU
. /
v
%0 0 '600°8000
Y lUIl*/v
10 2
000 0
o ,/
t
00
C
0
Y1 U1 /v y!
0i p
10
15
20 U/U.
ull/Ul
PLOT 4 CASE 0112 FILE 4 3.- o
1.0
u-,O - 14.4
0 00 I
0
y/a
0
0 0 o
t1I90
000~
05 ~
0
S~0
I0
0
00
0.0 • 0
V/Umax.0
209
0.05
.1s
PLOT 5 CASE 0112 FILE 4 1.0 z0
00
y/a
0
0
0.5
0 00
0 0 0 0 0 0 0 0 0
&o
0.0
0.1
0.05
0
PLOT 6 CASE 0112 FILE 4
00
y,/a
0 o
I
0.5 L-
0
0
0
00
20
0.000
o
-
_0.o5
(v2 ) 1/2/Umax,o
210
PLOT 7 CASE 0112 FILE 4 1.0 0
0
y/a
0
0 0 0
0
0.5
0
0 0 0 0 0
0.0
(w2) 1/ 2/U max.
PLOT 8 CASE 0112 FILE 4 0
1.0 0
0o
y/a
00
00 0 0 0 0 0 0 i
0.0
-0.002
I
-0.001
0
0
0.001
211
0.2
PLOT 9 CASE 0112 FILE 4 1.0 ze0 0 0 0
0
y/a
0
0.5
0 0
0 00
0.0 0
50
c
212
(m 2 /sec')
100
ENTRY ZONE OF ROUND TUBE
1-low 0130 Evaluator:
J.
B. Jones
SUMtIRY
This
test
case
*•
fluid in
the inlet
.
uniform
velocity
(see
Fig.
boundary S"x/D '.
I).
is
the
axisymmetric
region of a smooth straight profile
and
Roughness
layer
steady
.
is
zero-thickness
elements
turbulent.
on
the
flow
of
incompressible
pipe of circular
boundary
layer
tube wall
Free-stream
an
near
turbulence
Newtoniar
cross-section,
at
the
x/D
=
intensity
inlet,
x/D
insure
0 is
less
with a
than
0
-
that
the at
1%
=0. VARIABLES AND THEIR RANGES Variables
are
mean
velocity
function of radial
(r/R)
and axial
(U
or,
(x/D)
in
dimensionless
location
form,
U/Ub
for various values
or
U/Uc)
as
of Reynolds
a
num-
ber.
The region of interest extends from the pipe inlet plane to the section at which
fully
developed
quantities)
is
flow (i.e., attained.
For this flow,
data meeting the
though Reynolds number as
a
standard
550,000, only in A blocked
and
of Re
is
for
1,300,000.
-
convenient
from 0
for
Uc
For Reynolds
or blockage
-
U
is
a
numbers value
phenomenon.
velocity,
are
detailed
correlating
limited
to
velocity-profile
velocity-profile
factor B, which is
at
Re
=
388,00,
data are
Re
available
development
is
the
related to other velocity profile
of
When
displacement
plotted against x/D,
of x/D
Ub
1-•
U c
00, and
r
- fR
ax
shoot"
Al-
to 43.5.
*
at
listed below are sparse.
by
Ub - m/PA,
centerline
than 120.
data of satisfactory quality to serve
calculations
26 ax• R where
mean velocities and turbulence
selection criteria
Suitable
parameter
area fraction
of all
an important variable,
comparison
the x/D ran'le
characteribtics
zero axial gradient
This occurs at an x/D value greater
dr
-
U
0
c
100,000 and higher, between
B (as
thickness,
well
20 and as
several
momentum
a maximum is
35.
R the
boundary layer
Of
special
other
thickness,
seen to occur in
interest
parameters and kinetic
the region
reaches
such
the pipe
is
the
as
centerline
"over-
energy coefficient) 30 < x/D < 40.
(The
213
:-' ,.. . -• . _-,.. . • :,.). ,,"..> • . •.- ..L,-.,
-. .A- - -. ••
.
•.
.-.- .- . . .-(., .- . - . ." • " i
-
--.
occurs also in rectangular and parallel plane channels in turbu-
overshoot phenomenoil lent flow.) The
following
criteria
explicit
observed
dare
in
data
selecting
for
suitable
checking calculations of turbulent pipe-entrance flows: -.
The flow-passage
geometry must be fully specified and veritied to be a straight
smooth circular pipe. 2.
The flow conditions at the pipe inlet plane must be specified and must be nearly swirl-free,
The inlet flow must be verified as steady,
unifcrw across the pipe.
Differ-
and free of circumferential variations of mean quantities.
symmetrical,
ent shapes of contractions or diffusers upstream of the pipe entrance cause difso the radial variation of mean
ferenc velocity distributions at the iniet plane,
velocity and the free-stream turbulence intensity at the pipe inlet plane must be measured. -3.
Data must be demonstrated to be reasonably free of sources of experimental error such as
and the several
pulsations,
inlet flow distortions,
possible probe er-
rors. 4.
Descriptions of measurement methods and data-reductioa techniques must be adequate for evaluation and for the making of at least partial uncertainty analyses.
5.
Results must be internally consistent and physically reasonable.
.'.-
DATA SELECTED
and Jnaes (range
The data file for
(1963).
0.529
to
as standards
data selected
The mean-velocity
vs.
1.000)
r/R
of comparison are those of Barbin tabulated
this flow contoins 0 to
(range
0.
) for various x/D (range
1.5
to
Static pressure data are also in the data i le.
43.5).
Tabulations
of B vs.
Barbin and Jones (1963) 1,300,000
x/D
to
x/D (range
and B vs.
by Miller (1971)
1.5
(range
are in
43.5)
at
12 to 84)
the data file.
Re -
Pozzornin,
388,000
Re -
a.
are given by
550,000
and
Re
-
Figure 2 shows the variation of B
with x/D as determined in the three studies (Barbin ant J,,nes, *
values of U/Urax
1963; Miller, 1971; and
1976).
FURTRER DATA NEEDS A literature
search and study have shown clearly tht .ieed for full experimental ( locity fleld in the inlet
description of the mean velocity field and the turbulenc region of a pipe,
extending from the inlet to a section at which fully developed flow
has been estab]4.ihed.
1. "
Specific requirements are as follows: (In
The geometry must be fully specified. dom been described much more is
known about turbulent
contraction shapes have sel-
.
.
Until
flow through contractions and the effects of 214
2.*
the past,
to the extent that duplicates could be constructed.)
--
inlet
boundary
layers
on
pipe-inlet
flow,
provision
for
eliminating
inlet
boundary layers should be made. 2.
Inlet
flow
inadequate
must to
be
say,
fully
"The
specified
inlet
and
boundary
verified
layer
was
by
thin,"
measurement. or
"The
(It
is
inlet velocity
profile was uniform over at leabt eighty per cent of the pipe diameter.") 3.
Checks
of symmetry,
nelts,
and uniformity studied.
C:tio.a
uniform inlet
flow steadiness,
freedom from tangential mean-velocity
of the inlet flov, must be made carefully
Pozzorinl
flow.
The
(1976)
discusse3
location of
the
for each flow con-
difficulties
boundary-layer
compo-
in
transition
obtaining
should
be
a
fixed,
and checks should be made against circumferential variations. '.
Measurements
should be made over at least a 10-to-l
minimum range S.
Necessary
corrections
proximity, it
is
of 50,000 to 500,000 is to velocity
velocity gradients,
recognized
that
A
suggested.
probe readings
probe blockage,
additional
range of Reynolds numbers.
.esearch
is
for effects
of turbulence,
wall
and shear should be made,
although
needed
of
to establish
some
these
corrections. 6.
Direct wall-3hear-stress measurements would be advisable.
7.
Careful measuremetits ial variations
should be made to detect any periodic circumferential or ax-
of mean quantities.
development has been diecovered, E.
Until
a
equipment,
fully it
!41
reliable
Evidence
as shorni b)
calibration
flow
is
of an oscillatory Laws et al. availahle
chavacter of
flow
(1979). for
turbulence-measuring
wo-ald be we'.l for turbulence measurements to be checked by indepen-
dent instrumentation. REFgNCES Barbin, A. R., and J. B. Jones (1963). "Turbulent smooth pipe," Journal of Basic EnqinpeLing, Trans. Laws,
E. 4. , E. H. Lim, and J. L. ment aad decay," Proceedings 4.11.
Liv'esey (1979). of the Symposium
flow in the inlet region of ASME, Series D, 85:1, 29-34.
'Turbulent pipe on Shear Flow,
"Performance of strailht-wall diffusers Miller, D. (19711. nal Flow. A Guide to Losses in Pipe and Duct Systems, Englai:d, pn, 82-86, 106-109.
a
flows in developLondon, pp. 4.6-
(1971)" Part II of InterBHRA, Cranfield, Bedford,
Pozzorini, R. (1976). "Das turbulente Str6mungsfeld in einem langen KreiskegelDiffusor," Ph.D. Dissertation, ETH Zirich. Eduard Truninger AG, Zarich.
215
L.
' .
".
D
-2R
Figure 1.Nomenclature
it
(2)~~~
80
70
600
5a
210 I (30 m0
1
0
.8X1
0.226
0.15..
..
...
-
--.-..
.
..
.
.
..
.
..
.
..
.
..
.
.
DISCUSSION
Flow 0130 There was well initial
specified,
some
discussion
but it
boundary-layer
was
as
to whether the
pointed out
thickness
tihat the
as long as
it
initial
conditioný. were not
results may
is
small.
be too
This
[Ed:
sufficiently sensitive
flow was not
to fi-
nally selected as a test case for the 1981 ineeti.n..1
•,.I
J.
Jones
G. Lilley
.
-
..
~
.
..
.
_____________________________________________
217
.
.-.-...
.
.
-.-.
~.
-
-
.-
NUMERICAL CHECKS E. Reshotko The Organizing first attempt
"complex"
Each
Committee
haA
proposed ut
to calculate certain
turbulent flows.
"complex"
an early
stage that
computors
should
laminar flows before proceeding
to tLhe
Thu four check cases chosen were:
1.
Potential
flow in 900 corner
2.
Howarth flow (solutLion bj Bziley)
3.
Axisymmetric jet flow (solution in Rosenhead)
4.
Flow in a square cavity with a moving lid.
flow was presented to the neeting in turn and arguments given for its introduc-
tion as a check caEr. DISCUSSION 1. The consensus
turbulent-flow may
drawn.
by
that
calculation
algorithm,
not be good
agreed
2.
waa
laminar
flow.
It
was
to request that computors
namely,
a doubling
strongly
a goo(
good for
proposed
check
for
turbulent
by
P.
a
flow
Saffman and
proposed by Reshotko be with-
it
was esiggested
was considered
of
mesh size
or
equivalent
someone be invited
to
tionr-
fnv
review
deterioration of accuracy if
A halving of mesh
size
(for
the 1981 meeting
review paper on the numerical issues involved the
and it
was
example,
a
or at least one entry flow case.
expert
example,
very important
should perform at least one independence check,
kapproximately)
higher-order numerical scheme)
(Ed.:
not
(Ed: This has been done.]
decided
Finally
is
that is
that the numerical checks
The question of grid-size independence
3.
flows
because an algorithm
for laminar
the Conference
of
might
include
the mesh is
has been
a
in
to provide an
the Conference computa-
discussion
of
the
pctential
made too small.t
requested,
or
if
this is
not
possible,
a
doubling.)
LB.
E. Launder and W. Rodi have agreed to consider numerical problems and report to
the 1981 meeting. B. E. Launder is to be the evolved when the comp'itations are accumulated.
overall
coordinator;
details
will
be
218
.-.' . °.. -.,,, ', .- ,: ,. .- . . . ..
I -L.. I. . •<
:, ;.
.'.
.
.
"
..
.
=-. ... ..
•-, •.
.
-.
_....•
.
?. i . o '
;
"
SESSION V
PChairman:
A. Roshk,)
Technical Recorders: E. Adams
1
H. L. Moses
Flw
41
Flow 0440
Flow 0140
Flow 0430
2)9
*
E"ALUATION OF BLUFF-BODY,
FLC.JS
EAR-WAYJ-
ilow 0410 0412, 0413 and 0414
Cases 0411,
B. Cantwell
Evaluatcr:
SUMMARY
Any evaluation of bluff-body,
near-wake flows has to deal with two problems wolch
make a reliable evaluation very difficult. Lte near wake is
i)
is a region which can be measured effectively c.nly by a velocity-
It
mean velocity.
intensity and low or reverse
a region of high turbulence
biased hot wire or a frequency-shifted LDA. ii)
Redundant cases
very ).imited.
The numher of data sets for the near wake is
do not exist, and eicl available case represents a "one-lab" exj'eriiaent. The
remainder of this summary states selection criteria ard discusses
four spe-
cific possible cases. SELECTION CRITERIA Selection Criteria Based on Physical Considerations 1.
number:
Reynolds
avoid significant
chosen to
the Reynolds number should be
ef-
fects of transition. Mach number: data selected for comparison with incompressible calculations should
2.
be at a Mach number less than about 0.3. 3.
Surface
roughness:
tens of microinches measurements
at
height on the order of a few
practice a surface-roughness
in
is usually satisfactory for typical cylinder dimensions.
Re > 106
the surface roughness
For
needs to be characterized very
carefully. Wind-tunnel blockage: blockage should be less than about 5% to avoid the need for
4.
correction. 5.
Aspect ratio, ratio,
should include
1974).
Venting
avoided if 6.
end effects,
of
three-dimensionality:
properly
designed
the separated
end plates
flow zone
regardless of aspect
all models,
through
(see,
foi- example,
probe insertion
Stansby, should be
at all possible.
Free-stream turbulence:
free-stream turbulence
levels should be less than about "
0. 5%.
Department of Aero.
and Astro.,
Stanford University,
Stanford,
CA
94305.
220
•~~~~~~~.-.-.,-..-..-........-.......,.
.,....,....
.....
--.
•..,....,...,
•
.
Selection Criteria Based on Measurement Flying hot wire:
1I.
in
separated
Considerations
the flying hot wire'can be used effectively
flows.
Measurement
nary hot-wire measurements, tion of a bias velocity.
unccLtainties
to make measurements
are somewhat
higher
than in
ordi-
due to decreased sensitivity arising from the addi-
Conventional
fixed hot-wire
data taken in
the first
5-7
reliable
data
diameters of the near wake are unusable.
S2.
Laser-Doppler
with
frequency
on mean velocities
counter
the LDA can provide
and turbulence quantities in
processing is
correcting
shift:
accurate,
separated flows.
preferred over tracker processing.
sampling bias
is
Single particle
A suitable method for
essential.
Other Selection Criteria 1. 1
The data should include measurements
2.
Velocity
of
CD,
CL,
and Strouhal number.
and stress data should be provided on a grid which
to permit
is
su.fl..cntly dense
reasonably accurate interpolations.
3.
Measurements should include both lateral
4.
If
unsteady data are included,
in
time so that time can be treated as an independent
5.
Unsteady data
6.
The data should include a specification of measurement uncertainties.
7.
The data should include measurements at several Reynolds numbers and/or Mach -m-
should include
and longitudinal
velocity components.
they should tabulate a sufficient
sufficient
information
number of points
variable. for estimating vortex circv-
lation.
bers.
Cantwell and Coles (1980).
Case 0411.
This data set involves at a Reynolds
wind
tunnel.
taken Data
two
from the two probes with each
final
free-stream
with
velocity
end plates
Data
tion
streamwise
lateral
probes
Fig.
was
2120
turbulence 60.96
cm in
ground
half
1
level
and
data.
of
of
the mean
of
the
probe
outside
3600
span showed
ends
a
arm.
confined
of
rotating
The
-0.5
< x/D < 8.0.
was
roughness
pressure
Measurements small
30
to
100 ucm.
at
the
base-pressure
variation
.......
uspect
The cylinder
suggesting
.
cen-
distribugood
221
...........--.....-........................
cm/s. fitted
distribution
of the
of
to The
2159.56
cylinder model
ratio was 0.042.
surface
good
to a plane normal
The cylinder had an overall
surface
a very
and
together
bias velocity was
0.6%.
The blockage
1.
the cylinder model.
are
< y/D < 3.0
2 cm thick.
an
were
sets were averaged
data
The
to
componens
the
velocity
to pro-
than
27 to
the CALCIT 10-ft
two
was
less
in
in
The -3.0
on
out
cylinder
sets of measurements which were
10 cm/s.
diam and
lapped
The
1).
and
mounted
independent
the cylinder covering
position of one
was carried
the
and turbulence
include measurements
along
(see
the near wake of a 10.137-cm-dia:
The experiment
x-array
the end plates
centerless
terplane
of
provided
other
velocity
free-stream
"ratio between was
140,000.
independent
the centerline of
The
of
Measurements
using
agreement duce
number
measurements in
. ............
two-
(Cpb
ficient
*
were within
the ensemble
very
of
region
This
Data
uncertainty area
troublesome
tive
4-8% in
is
in
quence
This occurred
0.6)
diam of
0.7
1.5
about
set
oncoming
includes
in
in a
diam downcenterline.
the wake
(see
the full
which pass
data arcs
by probe
flow and are unaffected
were
encountered
was
set of arcs with concomitant
10-.5% in
±
bubble
described. processing,
final
before
deleted
limited to the first
mean velocity,
just
interference
probe
the
experience
within one
A second
stress).
Rcynolds
diAmeter
of
the
cylinder
of arcs which pass through the
Although the turbulence level is low in this region, the mean a result,
low.
As
leads
to a
mean)
is
the small uncertainty
uncertainty
large
(±
the bias velocity
when
reasonably
good
two regions
ir
50%)
the measured
in thc
absolute The
subtracted-
(±
just described
Measurements
region.
the measurement
data do not
The
nur do
are
The
poorly documented.
total area of
described
stress).
".
of
covered only by the second set
local
to the
order
vectors
rela-
velocity
main
conse-
for purposes of comparison with computation iq that the flow {i. the mean recir-
5% of the
nent,
2%)
(±
culation bubble
just
the
recirculation
the
is also very
velocity
(compared
angle with
flow and
(±
wake at a steep angle. velocity
The first
difficulty
region is
This
center.
details).
of the affected area is
and coverage high
this
which
in
wire.
set includes data arcs which pass through the wake at a steep
oncoming
the
with
Angle
second
The
interference.
a small
at
the wake
through
for more
report
evaluation
vel•clty
of the flying hot wire
sets of data arcs
by two
covered
is
region
the
(on
and within ±
cylinder
the
center of
the
stream of
intensity
turbulence
high
hot
flying
the
of
continuously
updated
the wires.
of
sensitivity
of
range
the
were
to ensure that all
the velocity bias was insufficient
where
ered,
are speci-
small r!gion of the flow was encount-
One
were used.
calibrations
static
Conventional
*
feature
self-calibrating
the
using
experiment,
the
during
calibrations
Hot-wire
direction.
streamwise
the
in
units
.
three components
the vertical direction and 86
in
61 units
is
a grid which
fied on 0.1-diam centers in
veloci-
phase)
The data
turbulence.
and -!V, due to background
v ,
stress (U2,
of Reynolds "'
2
Measurements
fixed
along with all
the atreamwise and lateral directions,
ties U and V in
at
ensemble-averaged
well as
as
averaged
(globally
mean
include
sensor was used
the vortex shedding cycle.
unsteady mean data at 16 phases of
to produce
coef-
with other
agreed well
0.179)
A surface-pressure
the measured Reynolds number.
at
data on cylinders
base-pressure
1.227),
-
(Str
number
Strouhal
and
-1.21),
-
(CD
The drag coefficient
the flow.
dimensionality of
2-4% in
mean
on the third
include information
they include averages at constant
phase of
outside
v,.loclty,
±
comprise the
two regions
5-10% in
(spanwise)
about
Reynolds
velocity compo-
the unsteady surface-pressure
distribution. Recommendation This data
set
is
recommended
for
comparison
wit,.
and unsteady data are recommended without modification. 222
."-.-.'--
......
...........-.
computations.
Both
the
steady
Reeervations Data within
the
separation
bubble
has
high
uncertainty
and
is
quite
sparse.
Unsteady pressure distributions are not available. Case 0412.
Watmuff (1979)
and Perry and Watmuff (1979).
This data set involves measurements in major,
mIddle,
ments were
and minor axes equal
taken with
to 220,
the ellipsoid
the near-wake of an oblate ellipsoid with 127,
stationary
and 73 mm, and with
respectively.
the ellipsoid
Measure-
oscillating.
Measurements of the longitudinal and lateral velocity components were made using an xarray mounted
on a moving
support
(a
linear version
of the
flying hot wire).
The
model was mounted with its middle axis aligned with the oncoming stream.
Data were
taken in a plane through the center of the body normal to the major axis.
The dimen-
sions of the measurement plane are 140 mm in longitudinal
direction;
this area covers a substantial portion of the near and inter-
mediate wake. Re based probe was 3.8 m/s. The hot-wire
calibrations
amount of
were
obtained
using
(on the order of
hrs typically required for an experiment). 12.7
Hz.
a dynamic
calibration
scheme.
A modest
2% of the inferred mean velocity over 15 The shedding frequency for the stationary
In the oscillating case,
the body was rocked ± 50 about its
cross-stream axis at a frequency close to the natural shedding frequency. placed outside
7
on streamwise chord was 32,500. The bias velocity of the free-stream turbulence level was less than 0.3%. Accurate
drift was noted
ellipeoid was
the lateral direction and 2800 mm in the
the wake was used to produce unsteady
mean data at
"
A hot wire
16 phases of the
shedding cycle. Measurements include mean (globally averaged as well as ensembleaveraged at fixed phz-.) velocities ITand V in the streamwise and lateral directions, along with all three components of Reynolds stress (u-, (v2, and u--) due to background turbulence.
The data do not
on the ellipsoidal model, dimensional flow.
include measurements of lift,
drag,
or surface pressure
nor do they include out-of-plane measurements in this three-
Model surface roughness was not specified.
The blockage ratio was
0.08.
t.2
Recommendation This
data
set
is
recommended
for
inclusion with
the
Data Library
but
is
not
recommended for comparison with computations for 1981. Reservations The lack of any information on lift,
drag, or surface pressure is a serious flaw.
The data are confined to a single plane in a three-dimensional flow. model surface roughness would have been useful.
The blockage ratio is slightly higher
than is desirable.
The data are limited to a single Reynolds number.
Case 0413.
I.
Castro,
This case
P.
involves
varying porosity,
Measurements of
(i971). pulsed-wire
measurements
in
the near-wake
including the case of zero porosiiy.
of
flat plates
of
The measurements were carried
223 .
.*.
-
.
.
.
.
..
.
.
"
.
•'•%• L
••
•
"I"L
•
•
•
~
"
' - ....
..
. .- ,
'
•
V
,
•
'
'
".
-•
•
i
-•
.
out in a 3x2-ft test section with 41-mm-wide plates spanaing the two-foot length. velocity
and
turbulence
velocity component
data
are
very
sparse,
including measurements
of
•
.
The
only one
along the centerline of the wake.
Recommendation This data set is Case 0414.
Owen,
This work cylinder. inch-diam clude
not
F.
K.
recommended for comparison with computation.
and D. A.
involves
ditionally
of mean
averaged
data
st 3s5 data
at
information
on model drag,
the
form of
plied.
were
two phases
of
are of
included
or
estimates
to the cylinder axis extending
Ames
provide
cycle 1800
surface
and
the
pressure.
corrections
are not given.
for
the wake of
a
circular
2x2-ft wind tunnel on a one-
longitudinal
which
the shedding
lift,
in
in
167,000 and a Mach
and fluctuating
velocity histograms
Uncertainty
LDA measurements
carried out
at a Reynolds number
measurements
(1978).
frequency-shifted
The experiments model
Johnson
number of
and
lateral
velocity apart.
and
0.6.
velocities. Reynolds
inCon-
normal-
The data do not include
The LDA data are sampling
Data
presently
bias have not
The data are confined
in
been ap-
to a plane normal 1
7.6 diameters downstream of the cylinder center.
Recommendation This data form.
If
set is
not recommended
for comparison with computations
the following changes were made,
in
its
present
the data could be used:
1.
Correct the submitted data for sampling bias.
2.
Expand the unsteady data to include at least eight phases of the shedding cycle.
3.
Supplement
the
data with
information
on model
drag,
lift,
and
surfac.-
with particular attention to possible surface-shock locations. 4.
Include
a
detailed
allow blockage
description
of
wind-tunnel
corrections for calculations
geometry
and
wall
pressure, to
pressure,
to
of the transonic flow.
REFERENCES Cantwell, B. J. (1976). "A flying hot-wire study of the turbulent near-wake of a circular cylinder at a Reynolds number of 140,000," Ph.D. thesis, California Institute of Technology, Pasadena, California. Also B. J. Cantwell and D. E. Coles (1980), "Entrainment and transport in the near wake of a circular cylinder" (manuscript in preparation, on file at Stanford). Castro, 1. P. (1971). "Wake characteristics of two-dimensional perforated mal to an airstream.- J. Fluid Mech., 46, 599-609. Owen,
F. K. and D. A. AIAA Paper 78-18.
Johnson
(1978).
"Measurement
of unsteady
plates nor4
vortex flow fields,"
Stansby, P. K. (1974). "The effects of end plates on the base pressure coefficient a circular cylinder," Aeronaut. Jou., (January).
of
Watmuff, J. H. (1979). "Phase-averaged large-scale structures in thrse dimensional turbulent wakes," Ph.D. thesis, Dept. of Mech. Engrg., University of Melbourne, Australia. Also Report FM-12 by A. E. Perry and J. H. Watmuff, 1979.
224
-7
t.
1.2
*0
1.0
0.8
Wire Set 1.
Ao
SWire Set 2 0.60 U 0.4
-2.0
-1.0
0.0
y/D
0.10
QWire
Set 1
0 A
~
Wire Set 2
Ao0 0
uv
2
V.O
0.0.
-2.0
-1.0
yID Figure 1.
Mean streamnvise velocity and shearing stress due to background turbulence measured by two independent x-arrays of the flying hot wire at xID -1.0. (Cantwell-Coles, 1980). 225
,/
DISCUSSION Flow 0410 A. I. 2. 3.
Circular Cylinder (Cantwell/Coles) The computation output should also include C(0) ana not only CP * nyCpb' o (0 an A non-steady computation should also include CL(t).t Thia
should
might
at
be on
this
the list
stage
of entry
require
a simpler
existing entiy test cases, which if 4.
A data set is
test cases because this approach
than
(non-steady)
the methods used
case
for the
used, could appear too difficult.
needed for a two-dimensional bluff body flow with fixed separation
points. B. I.
Wake of Ellipsoid (Perry/Watmuff) It
was recommended that this case should be added to the Data Library but it
not recommended as a test case for the 1980/81
Conference.
the grounds that data were not given on the body,
was
This was largely on
and wake data were only given
in the center plane. 2.
It
is
necessary to obtain CD,
Cp(6, x
-
0) and the tunnel-geometry
specification
for the updated file. C.
Circular Cylinder at
1.
It
"2.
It
M-
0.6 (Owen/Johnson)
was confirmed that this case should not be used in the 1981 Conference. was
recommended
number of
that
approximately
LDA measurements 140,000
to provide
be made at a
M < 0.25
at a Reynolds
suitable second data set
to Case
0411. The following comment was received from M. Morkovin after the 1980 meeting: "I observe
that
from the measurements with
the flying wire,
the indicated mean
velocity defect decreases much faster with x/D than in the results given in Abramovich and Schlichting.
This is disturbing.
bility of redundant measurements, mean velocity defect with x/D?
In view of the general consensus on the desira-
do Cantwell and Coles have such measurements for the If
not,
would they be able to make simple additional
measurements before :omputors tackle this challenging complex flow?" [Ed.:
This has been looked into,
an experiment to do this.
It
but so far it
has not been possible to devise
remains an important action to be completed.]
'-4
-'
*f[Ed.: •[Ed required,
This recommendation has been included in the specification.] No data exist
for C (t)
for this
but can be presented if dasired.] 226
flow.
Hence
computation will not
be
SI-CIFICATIONS FOR COMPUTATION ENTRY TEST CASE/INCOMPRESSIBLE Cace #0411.; Data Evaluator: B. Cantwell Data Takers: B. Cantwell and D. Coles FICYCOSL" SUIWSAl DthotKwoI..itor
71". 0410.
S. Cantwell1.
mosr-4I~o Flow.,
*g..1.,tioft of s*.i-Sady.
wombr of Stott*". Nosu
case*%ry
Dots Taar
C
Code0411
Ma.-.
1 . costwell
fo.
0.
~
W
.2
Ib
pro#-
Cles
I
gore Too- Too- Tooa yes.
-3.0 *0.1
(1-1).
Ordinate
*Plot 1
C
~
1
61sI
1
~
I
1tiesae
14
1
'Ne
'a
TOO o"
4
cylts-
Other Face
F~ lytag %.t-1ro"toa.
lee
e@
oyo
safed
0.§1 I Oaat~adr "to5 ieo1d"..
1..0
F/D
Loestioei y/0
C
V
/0
-0.5
0.1 (J-1).
I
j Ile £.
Abscissa
Range/Position
6
0 < 0 < 3600
Comments Model surface pressure.
2
UCL/Uref
x/D
0.5 < x/D < 8.0
3
y/D
22 U2IUref
-1.5 < y/D < 1.5
Mean normal stress at x/D 1.5. See note after Spec. Instructions.
y/D
v2/ 2
-1.5 < y/D < 1.5 rof
Mean normal stress at xID - 1.5. See note after Spec. Instructions.
-1.5 < y/D < 1.5
Mean shear stress at x/D -15 See note after Spec. Instructions.
4
5
y/D
2vue
Mean centerline velocity distribution.
6 optional
y/D
/Ure -3.0 < y/D < 3.0 rfx/D
Unsteady mean shear stress at - 1.3, phase 7.
7 optional
y/D
/Uref
-3.0 < y/D < 3.0
Unsteady mean shear stress at x/D - 2.9, phase 7.
8 optional
y/D
/Uref
-3.0 < y/D < 3.0
Unsteady mean shear stress at x/D NO4.0, phase 7.
9 optional
y/D
(UV>/Uref
-3.0 < y/D < 3.0
Unsteady mean shear stress at x/D - 5.3, phase 7.
10 cptional
V/Uref
x/D
0.5 < x/D < 8.0
227
Unsteady lateral velocity component along the wake certerline at phase 7.
Special Instructions: This data set includes both steady and unsteady data in lar cylinder. concentrate .
It
on
is
anticipated
that computations
the globally averaged
mean flow,
eddy simulations of this flow may utilize computation marked
is
cartied out,
optional.
In
addition,
the
the
Plots 1-5,
should
computor
report
should
results
report
number for comparison with the measured Strouhal number. the uniteady For
the
lift
CL(t),
computor
1980-81
although
to
compute
the
for
will
eventually largeIf
an unsteady
items
the value ot
6-10 above
the
Strouhal
The compt-or may also report
although data for comparison with CL(t) who wishes
Conference
the unsteady measurements.
computor
thc
for
the near wake of a circu-
entire
flow
are not available. field
including
tunnel
walls, relevant dimenqions are as follows:Contraction ratio:
9:1.
Test section diameter:
3.048 m. 3.048 m.
Test section length: Model diameter: The center of
the cylinder was
0.10137 m.
located 0.61
m downstream of
the entrance
to the test
section and 0.152 m above the tunurl centerline. Note:
Mean ReytLolds stresses mean stress
(Plots 3,
due to background
periodic motion constructed ity data in
files
4,
and 5)
tirbulence
in
must be constructed file
by summing
the
18 with the stress due to
the
by squaring and averaging the unsteady mean veloc-
2 through 17.
•-2<-228
.
228
PLOT 1 CASE 0411 FILE 19
II
"
i
I
"
' "
"
~~o 0
0
0 00
0
0
0
0
-1
I
.
.
.
0
I
.
.
.
100
.
.
,
200
,
,
300
e (deg) PLOT 2 CASE 0411 FILE 18 10I
I
I
4
6
'
1.0
UCL ref00000
/
U
Uq./Ure
0.
05
0
*
0 00
0.0
0
2
x/D
229
8
PLOT 3 CASE 0411 FILE 18 x/D - 1.5
0
y/D
0 00
0
0
1 5
0 I
-1
0
0 07 0
o
0.2
0.1 00 0
PLOT 4 CASE 0411 FILE 18
r
"
- .15,
x /D
S0 0
T
0
0
y'',/D
0
° O-
0•-1'0
0
0.2
230
0.4
18 PLOT 5 CASE 0411 FILE X/D- 1
.
j
/ -
y/D 0
0
0/
x/
1 .3
-0 0411 FILE 8 6 CASE PLOT 0O
0 0
0 0
-10
0o 0O
1
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O
00.i
00I
0
0
0
0 0
0
y/D
0 o0 o0
0
0
0 -1
¢0
00
o
00 0
0o 0o
02
-
00Ure
231
j
PLOT 7 CASE 0411 FILE 8 2.9
x/D
00 0 y/D 0 00
* 000
09
0
-2
0
-0.05
0.05
/U 2f
PLOT 8 CASE 0411 FILE 8
00 00
0
- 4.0
OJx/D
I
0 08 000
008 0000
00
2
2r
-2
0.02
0
-0.02
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232
PLOT 9 CASE 0411 FILE 8
2
5. 3
x/D
2
loo
I 0% 00
0 0o
y/D 000
0 08 *00
-2
0
0.5
0.02
0
-0.02
000
00
PLOT 10 CASE 0411 FILE 83 I
II
0.5
6P%%°o0
"
00
0
0
0
o0
V~
0
0
0
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0U 0
00 00 0
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6
4
2
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233
8
TWO-DIMENSIONAL STALLED AIRFOIL Flow 0440 Case 0441 A.
Evaluator:
Wadcock*
J.
SUMMARY
set
only data
Thc
investigation
of accuracy
possible problems or limitations
*
technique both
of
unconventional,
x/c
airfoil
trailing
and
The attached
near wake
the
It
and an
technqiue
experimental
remains
to identify
The measurement
data set.
some doubts have been voiced regarding
flow being measured and the accuracy of the
to the
the flying hot wire. 0.620,
-
of
this single recommended
in
and understandably
the possible disturbance
obtained by
scrutiny
that of Coles and Wadcock (1979).
is
*
is
a close
warranting
is
data
documented downstream
boundary layer is
the
for one chord length downstream of
covered
edge.
L.
CALIBRATION PROCEDURES Compound Test Section The model wind tunnel
mounted
was
(see
Figs.
plane
between
end
parallel
3 and 5 of Wadcock,
and qref (with sure test
difference section.
airflow is
tunnel
At
two
large
(with the model abt:ent) ter
rings.
velocity
that
in
Figs.
region
the wind-tunnel
Wadco,:k
(1978).
Wadcck
NASA-Ames Research Center,
In
large
for
a compound
fraction
of
the
in
from the tunnel
the
dynamic pressure defined by the piezomeof both pressure and velocity data which respectively.
the roof-mounted the
a
have at some point
roof was used to measure Uref. of
applicable
compound test section arises
by C..nf and Uinf,
event
that all
the tunnel walls,
of calculation by f.r•ludlng
pi'rpose can be found in
not
insert.
flow would
the presentation
The position
normalizations. 3 and 5 of
the
is
high drag),
this
for a given reference
Th!s tomplicates
mounted near data
(i.e.,
from the use of
are normally made non-dimensional
all
rings
piezometer
of attack
diverted outside the two-dimensional
to know Ui,1f--the
The usual practice of cali-
at the same flow rate as indicated by the same pres-
istream angles
The main complication need
circular-section
by measuring the dynamic pressure q nf (with the model absent)
the model present) from
a
No allowance was made for boundary-
1978).
layer growth on the end plat-s or the tunnel side walls. brating the wind
in
plates
it
tube
A pitot-static
This quantity was used in tube
picot-static is
necessary
information
is
shown
to bound
required
the
for this
(1978).
M:..ffiw
Field,
94035.
CA 234
.
.
.
.
.. S- -
--.
..
~.*. ~
.". --..
.
.
.
-
-
--
..
.,
-•
of the Mean Flow
Two-Dimensionality
"To tached
encourage
to both surfaces
"thick and centered sure
uniform
4 mm wide, at
side
point.
transition
of the airfoil.
the
trip
was
the
span,
The trips
with a sawtooth
x/c - 0.025,
The
across
boundary-layer
were narrow
leading edge.
trips were
strips of
tape 0.15 mm
On the suction side,
the trip
slightly downstream from the pressure minimum.
centered at
x/c
- 0.103,
trips had no measurable effect
well downstream
on the
at-
was
On the pres-
from the stagnation
surface-pressure
distribution
even
near the leading edge. A passive method the
side walls
(see
two-dimensional (1978).
Flow
separation
"Model
Fig.
flow.
control which
13 of The
Wadcock,
resultant
visualization
(see
relied on
1978) flow
was
is
Wadcock,
the
experiment,
system
aligned with the the horizontal With system
in
for
Figs.
and
11
photograph)
in
14
creating
of
suggested
Wadcock that
the
the
was
defined
measurements
by
the
tunnel axis.
tunnel
measured
pattern
all
traverse
The vertical
of
off, as
the
position
detailed
between the real with
a
deflection
optical
proximity
signal,
a
attached
wave
of
in
length
of
the
Wadcock
of
in
the model
gold-coated
the wing
side of the nmid-span change
surface
about
line.
displacement
This
the trailing
be taken
air
was
of
to
a
accurately
to 0.0025 cm,
and
These
sections. cm and an
respect
to
the
measurements
may
a
established
The real surface showed a amplitude
from an aerodynamic
of
the
tape, of
rotor.
0.9
of
about
have
the
rotation of
angle
of
point of view.
been partly
model
to
edge wau determined
to
analytical
and 0.007 cm
the rotor,
fixed be
the
position
13.87 -
0.01
to an
accuracy
235
** .
-
of
some
thick,
11
0.155 cm normal
deflection
to
and partly
the air-on
formulas
*'..
of
which describe
the
was
cm to one the
the model the chord strut
de-
of 0.(;2
location of the the NACA 4412
chord line and also deflied
degrees.
tion of these delicate measurements can be found in
*
small
turning at standard speed,
finally determined by fitting
proceas
incidence
translation
cm.
immaterial.
suction surface This
0.01
To obtain a strong sensor
cm wide
With the rotor
simple
traverse
load was measured with the aid of a
on one arm
the plane
as
position was
profile.
real
motion
_.rfoil with
(1978).
25
reflective
in
but the distinction is
The airfoil
airfoil
referred
sensor signal from the air-off to the air-on condition showed that could
rear part
under
pressure orifices.
displacement
flecthon,
whose
were
traverse was repeatable
and ideal airfoil
sensor mounted of
strip to
position
mechanism
These discrepancies are unlikely to be important The
probe
travers to 0.01 cm.
discrepancies
•
found to be successful
shown
1978,
sheets mounted on
Position
coordinate
the
simple metal
line was reasonably straight over the central meter of the span.
During
waxry
of flow
The cm.
streamwise
position
of
A more detailed descrip-
Wadcock (1978).
L
Data Placement The airfoil grees
in
may be misplaced
angle of
incidence.
by 0.02
The
cm in
x,
by 0.01
in
y,
and
by 0.01 de-
position of data points along the probe arc may be
uncertain by as much as 0.1 cm over and above the effect of because of strut deflection
cm
non-simultaneous sampling,
and also because of systematic local irregularities
in
the
encoder signal. Further both
in
uncertainty
model and
strut.
relative
Ddring
the
from vibration and
position occurs
grazing
traverse,
observed
buffeting of
peak-to-peak
excursions
I..
about 0.034 cm.
in proximity sensor voltage indicated a peak-to-peak displacement of The rms voltages and displacements were about one-fourth these values. sion were all peak the
caused by displacement
motion
would
be
0.035 cm.
strut and rotor hub in
0.080 cm.
of
If
the airfoil
the excursion were all
the streamwise
Both estimates are
normal to
direction,
reasonable,
If
the chord,
caused
the peak-to-
displacement
of
the peak-to-peak motion would
be
and the actual motion is
by
this excur-
probably a combina-
tion of the two. The Flying Hot Wire and Related Instrumentation The
main
whirling
arm.
velocity. that the is
In
experimental The
rectification
practice,
direction of
always
within
technique
the
uses
a
problem
the tip speed of
flying hot is
thus
1978).
wire mounted on
avoided
by
the end of
biasing
the
a
relative
the whirling arm can be made large enough so
the relative
flow at
useful
of
range
(see Coles et al.,
the
about
probe 30
±
(a
standard commercial
degrees
with
respect
to
x-array) the
probe
axis. The angular position of and
a magnetic
nal.
pickup which
the motor shaft was encoded by a 256-tooth precision gear produced a
The encoder signal controlled
clean T-L pulse
not only the
rotor
train called speed but
hence the position ini the flow) of the hot-wire measurements. cm,
151.4 Lvery
with
256
equally
spaced
sampling
1.86 cm along the probe arc. Eight of the twelve analog data
(e.g.,
tunnul
temperature,
data channels were of the rotor. tip speed was
tunnel
reaerved
positionL.
the encoder sig-
also the
timing (and
The rotor diamete.r was
Digital
data
were
obtained ,,1
channels
dynamic
for hot-wire
surveyed carried
pressure,
data
from
model the
miscellaneous
surface
signals
pressure).
two x-arrays,
one on
Four
each arm
The rotor tip speed during the hot-wire measurements was 375 rpm. Tne 29.73 m/s. Each data file lasted for 2048 revolutions (5.46 min).
There are 85 such files
in
the main data base.
Hot-Wire Calibration The of
the
",
flying hot-wire
ordinary art of
occupies
a
technique
er..:ounters
hot-wire anemometry.
considcerahli, fraction
of
the
several One
tunnel
problems
problem is test
section,
which
5
°
"
•.
'":
".
are not
typical.
that the calibration arc and
236
5•
A
•.""
nonuniformities
of
7-._
r the
calibration
absolute
at
,"-
in
reference
frame
along
this
arc
may
measured velocity are
doubled
least
rays is
flow
errors
during conversion
fixed in
be
important.
conserved,
the tunnel.
For
the
present
experiment
frame
A third problem
it
was
second
problem
is
that
is
fixed
in the
probe to a
that calibration
of wire ar-
rained at dynantL:
impractical
to
remove
the
airfoil
model from
in
possible. The resulting calibration geometry is 3hown The magnitude of the free-stream velocity was deter-
six points along the calibration arc by means of a pitot-static pressure
detail in
used for wire calibration.
Coles et al.
A
of velocities.
the test section during wire calibration. Instead, the airfoil was pitched to -4 degrees (zero-lift angle), and the calibration arc was chosen to be as high and as far downstream from the airfoil as in Fig. 31 of Wadcock (1978).
"
and relative errors are therefore
from a reference
required over an unusually large range
A
tube
A sample probe calibration
is
'.A
.
..
-
for each
documented
(1978).
'-.
Benchmark Data
"lhe
main
events
of
the experiment
were the pre-test
calibration,
the horizontal,
vertical, grazing, and boundary-layer traverses, and the post-test calibration. The pre-test calibration was intended to anchor one end of the drifting data. However, at different times in the course of this calibration, three of the four wires showed sud-
den
small
changes
in
response.
pre-test calibration We
were
(duplicate
left
velocity The
the
post-test
represented
among the data
foind
to pull
the
data
together,
and
files.
The
along portions
U
of
by
the
key to the
calibration lowest
arc
and
in
control of drift
benchmark
arc
a
series
Fig.
34
was
of
"benchmark"
of Wadcock,
the determination of
which lay outside
the
test
time during
calibration.
parts
of
keep
The
the hench:aark
track
benchmark these
the
of
the
files
is
details arc
of
garantees
are
outside
hot-wire
drift,
fully the as
the
last
two benchmark
documented
boundary shown
in
in
layer Fig.
Wadcock and
2.
a
stable
that
the
the passage
mean
(as
hot-wire
internal self-consistency
of the
shown
drift
by
was
of the hot-wire
the under
of
This
Only
the
among
all
to
seven
data)
and
a measure
im-
further of
the
data.
SUMMARY OF CALIERATION PROCEDURES The scheme the
hot
wires
provided
were
information
calibration
post-test
calibrated on
wao
the
in flow
meaningful.
a
nonuniform
inclination Control 237
•
.
..
. ...
.
".
flow.
along of
drift
An
iterative
the calibration was
4
those
The agreement among
gives
._
and lin-
the wake illustrates the
rcpeatnnility control.
region.
wake were used
Agreement
probe through
spaced
and the post-
(1978).
airfoil
P°..
the mean
turbulent
runs
thus guaranteed over these regions of the arc.
files documenting
portance
period spanning
files
1978)
strategy used was to assume that the wire parameters changed continuously
early with
the
had to be discarded.
with
files
No way was
""
inversion arc.
Only
providad by use of
a
P'-
set of duplicate "benchmark"
-.
"the benchmark
files.
A bootstrap procedure was necessary to establish
velocity field.
The hot-wire data were
then inverted and the results stored on punched cards as
"raw data." The
following
uncertainty
estimates
have
been
calculated
corresponding
to
95%
confidence levels. Variable
Uncertainty Estimate
Intermittency U, V
± 0.04 0.03 Uref
u-,TV
± 6%
Note
,
the uncertainty
Is
0.02 Uref in regions of low turbulence)
expressed
as an
absolute
value
for
the mean-velocity
components and as a percentage for the Reynoldr stresses. DISAGREEMENT BETWEEN FLYING HOT-WIRE AND PITOT-STATIC MEASUREMENTS At this stage of the data processing,
it
was observed that velocity measurements
indicated by the hot wire outside both boundary layer and wake were lower Zhan corre3ponding measurements made with a pitot-static tube. stem from the way in which inferred,
(2)
flow inclination along
the way in which the benchmark velocity
combination of the two. ment.
(1) the
The disagreement
This correction
is
assumed to
the calibration
field was inferred,
or
arc was (3)
a
A small correction was made to the raw data to force agreeis
fully discussed in
Wadcock (1978);
it
amounted
to an in-
crease of 2% in the magnitude of the velocity relative to the probe. The agreement in the magnitude of the ve] data,
is within a fraction of 1% in all cases,
ity,
on both sides of the airfoil for values
of U/Uref from 1.0 to 1.4.
Elsewhere in the flow,
also changed.
stream,
In the
free
the
amounts.
changed in
axis)
magnitude by about 0.02, however,
as much as one the dimension-
and in angle
by unknown
have merely been multi-
by constAit factors close to unity.
The comparison between static traverse
the hot-wire data have
In the separation bubble,
The Reynolds stresses and higher moments,
plied everywhere
of course,
flow angles have changed by
degree at the extremities of the probe arcs. less mean velocity has
after correction of the hot-wire
the corrected
hot-wire
dtta and
the results
of a pitot-
through the wake (pitot-static tube aligned at 6 degrees to the tunnel
made in Fig.
23 of Wadcock (1978)
shows good agreement,
lending credence
to the
above correction.
r
"PROBE
INTERFERENCE
At an early stage of data processing, it became apparent fror an inspection of data (i.e., independent of any problems with wire calibration and drift)
Rintermittency
238
that was
there that
was
the passage
problem
with probe
the affected
fluid would move
of the free
stream)
the effect was
changes
in
by
rotor
original
acting,
small,
arising
the external hub was
from
distance
probe
as expected, the
extreme
pressure
field.
physically
small,
(two
passages.
the
sensitivity
is
of
an appreciable
and the blockage effect was substantial.
changes
outside
the boundary
with strong leverage The (see one
Fig.
37 of
surface
position
documented
Wadcock,
the
(1978)
rotation,
best
pressure
of
Wadcock
the
is
effect
on the separation
port
traverse provides
that
dLstrt.bution
for
dimensional;
the
1978).
The
were
found
system
and
confirmation
governed
traverse system
in
the magnitude
layer
varied with rotor
situation
required
is
terms
of
the
differences to
be
almost that of
surface
among
strongly
to
slight
to the
fraction
flow
of
the
The associated
position
and worked
was
to
in
Cp
found to be only 60 to 70Z of the required
at
of
The
3.
the
1/4-
the
largest
and
at
not
probe
effect occurs
effect
was
3/4-span
any
position.
and
The observed
The
airfoil
streamwisc
vertical
ositLion,
traverse.
Fig.
with
the
traverse
the
measurements
correlated
the effect.
on
pre3s'ire
repeated
independent
it
shown
corrections
that
process.
is set up for the boundary-layer
this
the case
kind of inter-
presented
itself,
velocity
in
separation
drag of the airfoil in
because
strong evidence
the obstacle
drag was
increment of
meters or more,
There
and that a different
Although
expectation
should be small
the effect
but that
a substantial
between surecessive
Just described was
ference
Our
interference.
of the rotor arm through the fluid would add a local
the direction of probe motion,
in
momentum
the
serious
a
when
pressure not
two-
stations
were
corrections at midspan.
The scheme used to cope with this problem of blockage was to discard the hot-wire data
for that
part of each grazing or
tant
region
strated
in
of the separation Fig.
5 for
the
bubble.
arc
downstream of the last graz-
has sacrificed
here
Agreement between
distribution of one of
be
ignored
separation but
for
all
horizontal
bubble can be
and vertical
trailing
traverse (as
can all
The
illu-
stresses across
edge.
data.
The
main
problem
part
the data in
of
the
the wake),
the boundary layer up to separation cannot.
PROCESSED DATA The a
-•
data of
numerical
the present experiment
analyst.
Further
data on a rectangular the
grid
Wadcock
grid.
in
question
(1978)
with
is
are awkw:ardly placed from the point of
processing
Mostly
aligned
Information
was
for c,..
with up
; .,ence
the
to and
therefore in
airfoil
carried
--
..
...
.
.
..
.
.
..
.
.
tn
fourth
Detoils moments.
....
.+
can
view of
redefine
describing the airfoil
chord.
including
out
239
-- -
-A
the impor-
remain in
the normal Reynolds
taken as interference-free
redundancy
the two sets of arcs is
the wake at a station slightly downstream from the airfoil can
much of the
different angles
at
two traverses
although
the original data,
of
outlined
scheme
The
4.
Fig.
ing arc--see
boundary-layer
the
surface, be
found
Wadcock
in
(1979)
L.
provides a partial tabulation of the processed data. chordwise
mean velocity,
and
three Reynolds
Shading has been used to emphasize
Contour plots of intermittency,
stresses are shown in
peaks and valleys.
Note that
Figs. 6a, these
figures
based on velocity components resolved along and normal to the chord line. ferent values and different contours might be obtained near the airfoil if nents were
resolved
more nearly along and normal to
conclusion from the Reynolds-stress data is
6b, 6c. are
Quite difthe compo-
the airfoil surface.
The main
that the separation process is relatively
regular up to the tralling edge of the airfoil.
The real challenge is
to understand
the merging process for the two shear layers just downstream of the trailing edge and the
subsequent
rapid
relaxation
toward
the
final
state of
a
conventional
wake far
downstream. SUNDRY COMMENTS 1.
No
experimental
limited
number
(1978),
measuremenLs of
boundary-layer
Any attempt
-.
of
"*.
velocity profile,
the hot-wire
available.
friction
velocity
have
profiles
been
published,
although
are
tabulated
in
a
Wadcock
to obtain an estimate for skin friction from a Clauser plot
data fails,
as
there
is
even at the earliest
Estimates
"plete law-of-the-wall
for the
a
negligible
boundary-layer
logarithmic
region to
station for which data are
skin trictiou will bc available (from
plus law-of-the-wake
the
fiL) at a later date.
a more com-
This will enable
momentum balance to be performed. 2.
A single boundqry-layer 0.820
- -
skin
the first point of each of which can be considered as a Preston-tube mea-
surement.
S'.a
of
is
profile on the pressure surface of the airfoil at
listed in the data files.
This provides the 3nly available
x/c
information
about the development of the boundary layer on the pressure surface: Re
Cf
1090
rf V
rw/qref = 0.0047
-
_ d T dx w
-_
0.152
REFERENCES Coles, D., B. Cantwell, and A. J. instrumentation," NASA CR-3066. Coles, D., nid A. J. Wadcock airfoil at maximum lift,"
Wadcock (1978).
"The flying hot wire and
related
(1979). "Flying hot-wire study of flow past a NACA 4412 AIAA Jou., 17, 321
Wadcock, A. J. (1978). "Flying hot-wire study of two-dimensiona'. turbulent separation on a NACA 4412 airfoil at maximum lift,'" Thesis, Caiifornia Instttute of Technology, Pasadena, California. Wadcock, A. J. (1979). "Structure of airfoil," NASA CR-152263.
the
turbulent separat,"
fliw around
a stalled
240
_:. -..--• *-.--"'**-.*.j. .
..
....
...
*
.
.
.
-
..
.
.
.
.
.-
.-
.
-
LL LU
LLLU <
u L U,
0
00
NN
LU] 1\
LL LUJ
U .. LUJ LU
I-
000
C-:
000
00
Ir
< ...JLU < .z
00
z ui
0,
L
<-
L
LL- (n
00
IL241
00
1
0
I
•..
d
U.
2..
Co
o
I
_j.
-44
V~ I
Figure 4.
Case 0441, location of probe trajectoricbs for main experiments, after downstream portion of grazing and bo~indary-layer traverses have been deleted. Arcs extend from Frame 40 'o Frame 115. Small white rectan~le chows region used for area interpolation. Large rectangle shows maxirum extent of grid used for processed data.
08
0
0
0
0~4
2
0000
02
0
m0
-5
4 A.,FigL-~e 5.
j
j
I
jn
510
vertical traverse:
15
0
horizontal trz~verse.
Case 0441, effect of rotor interference oiiwake thickness. Dependent variable is chordwise coa-ponent of turbuleOt energy, evaluated by linear interpolation in corre'-.ted raw data. Station is x 98.86 cm. 244
CASE
KFigure
6a.
I.y.
Figure 6b.
0441j
Contour plots of chordwise mean velocity UJ/U ef and intrermittency factor Contour intervzl is 0.1.
Contour plots of correlations
u2/(Uref)2,
*~iTIUe)Sad v/Ue)2.
Contour interval is 0.010 or 0.005."vv/Ue
Figure
6c.
?arttal display of Vector field of mean velocity. Top: same scale as Figs. 6a, b; bottom: close-up view of separated region. (Tick marks on chord line are at intervals of 0.1 in. x/c.). 245
%
DISCUSSION Flow 0440 It
I.
was recommended
that
some clariftcation
be given
to the data on the wall
geom-
etry and end plates. A
2.
cautionary
note
should
be
added
regarding
the
boundary-lay'r
These data should not be used as initial
separation.
data in
The location of the tranaition strips
4.
The
computation uutput should also incluoe profiles of mean velocity,
and
turbulent
energy
at
three
should be given in
chordwise
edge and in
the reverse-flow
The computation output should also include
5
xsep.
ri
246
-"
"".
."
.
of
the specifications.
(e.g.,
locations
upstream
computations.
3.
downstream of the trailing
Lit-
dxtta
before
region).
shear streus
separation,
just
VI
SPECIFICATIONS FOR COMPUTATION ENTRY TEST CASE/INCOMPRESSIBLE A.
Data Evaluator:
Case #0441;
Wadcock
A. Wadcock and D.
Data Takers:
Coles
FICIOOI&L, SIMQ*Y rim CA40.
Dozei tvstluil
l A. illtelc.
VI
"T•t-DlI
st.,
tof
v.'*cl7
Ooa
°ion.a.
t--Turb,.c.P-in
i SL I9i.ul
II~dAW-
."
""
re I,
l
Sal.to Tk.,
C... t,17 7
Cý0441
he.
~P. 2 2
I,< !
,uc%%
S•-
V colic " D.
I
12 125
11
I 1'
1
i2( nej I 2:.1 I~ne* 125
A.
ai/c <.
0ir-d).
0a/ O.ifl .
[ {
eotrto*2
Poe lrl-.
itretleprlo ....tnl/ calb rie !
0 0i
.I
-.
Comments
Ordinate
Abscissa
Range/Postrion
1
C
100 X/c
0 < 100 x/c < 100
Upper and lower surface pressure.
-8.0o < Cp <-1.0o.•
p:.
2
y/c
U/Uref
-0.13771
< y/c < 0.517
x/c - 0.642, 4 curves at 1.1747, and 1.95146 (IX52, 76, 100, 170).
0.908,
3
y/c
V/Uref
-0.13771
< y/c < 0.517
4 curves &t x/c - 0.642, 1.1747, and 1.95146 (IX - 52, 76, 100, 170).
0.908,
4
ylc
u-/U ef
-0.13771
< y/c < 0.517
4 curves at xlc - 0.642, 1.1747, and 1.95146 (IX - 52, 76, 100, 170).
0.908,
5
y/c
v2/Uref
-0.13771
< y/c < 0.517
4 curves at x/c - 0.642, 1.1747, and 1.95146
0.908,
76, 100, 170).
(IX -52, 6y/c
u-'V/Uref
P".--
Ij'od
Plot
p
tor.
hd b ...-. ry
I;
Of...
0.62
. .5
-
-0.13771
< y/c < 0.517
4 curves at x/c - 0.642, 1.1747, and 1.95146 (IX - 52, 76, 100, 170).
0.908,
Special Instructions: of
Definition
Special
q
(model absent); velocity
in
present);
Cp
uniform (p
-
Symbols: -
flow
c
-
chord:
dynamic
pressure
(model
absent),
in
qinf
flow
(model
velocity
in
uniform Uref
=
Pref)/ref"f 247
,
.
pressure
dynamic
.
far
upstream
present);
uniform
flow
Uinf (model
. .77
I
The
data for this case are defined with respect to cartesian coordinittes with the-
horizontal edge.
axis
The
aligned with
data
the
are contained
airfoil
in
a
chord
and the
two-dimensional
origLn at
grid with
the airfoil
indices
leading
IX and
IY with
ranges I < IX < 17j 1 < IY < 296 related to IX and IY by
x/c and y/c are
x/c y/c The
calculated
NACA 4412 airfoil the
at
configuration
distribution
static
at
(-62.05 + IY-1)/[(5)(90.117)]
pressure
an angle of
shown
in
a Reynolds
for the airfoil
(6.86 + IX-1)/90.117
distribution
attack
Fig.
i,
nutuber
of
on the
13.870,
should
be
(Oised on
surface of
mounted
compared
chord)
of
a
two-dimensional
between parallel walls
with
1.5
the
measured
in
pressure
x IC.
(Iee
for this
test case to best
data
On fil,'
geometry and C.)
p Computorb suit
their
are
free
flow-calculation
effects of the walls on
the
measured.
up the
walls
However, flow in
and
the
Appropriate approximations
entrance
to the test section musi to predict
boundary conditions
method.
on the airfoil
wind-tunnel
set out
to set
the complete
they
should
note
the experiment.
blockage
distribution
to the starting values of
flow field in
finite
The boundary-layer
tunnel-wall-pressure
Lherelore be intrcduced
the
in
6
,
0 ,
growth
were
and Cf
not
at the
calculation
methods which
the test section including
the boundary-
layer growth along the tunnel walls and the wall-pressure distribution. In a
order to check the suitability
blockage
calctlrA[:Ion
stream velocity tributions U/Uref was
on
distribution the
line
bases)
shown
are
measured
in
also shown in
the
at a
in
Fig.
Fig.
1.
flow field above the
location
below the
along and normal to the chord
trial
runs
and compared with
and V/Uref have been taken from
measured is
table
or other
of the chosen boundary conditions
lower
line,
I
can be made of
the measured
(data
presentud
Note that
free-
Table
I).
(The
The position
dis-
values
at which Uref
the velocity components given in
upper surface surface
the predLcted
free-stream velocity
in
the data on file).
(whether from
of
respectively.
of
the
airfoil,
the airfoil. Computors
whereas
Uref
the is
X and Y are measured should report
basis used
with restilts. When a achieved
in
satisfactory the
vicinity
prediction of
this
of the 'ree-stream line
proceed
with
ve~locity the
distribution has been
calculation
of
the
pressure
distribution around the airfoil.
248
[
.
..
'
It with
should be noted
the
4ystem
airfoil
(i.e.,
requested
that data on file are
chord. local
since
Computation
boundary-layer
computors
who
do
of
presented in
quantities
coordinates)
not
unable to transform Reynolds-stress data
calculate
a coordinate system aligned
applicable such
as
individual
6
to another ,
p,
normal
and
"'rdinate Cf
stresseb
from one coordiaatc system to another.
Table 1 The Values of
the Measured Velocity Components in the Freestream at Selected Positions (Wadcock, 1970)
x (M)
y (m)
U/Uref
V/Uref
0.6086
0.1039
1.2243
-0.0414
0.8086
0.1439
1.1688
0.0024
0.9586
0.171Q
1.1102
0.0167
1.1086
0.1919
1.0532
0.0650
1.2586
0.2159
1.0485
0.1093
1.4'86
0.2639
1.0523
0.1464
1.6586
0.3259
1.0532
0.1894
249
are will
not__ be
II PLOT 1 CASE 0441 FILE 3 2 00
000 0
Cp
-
2
0
o 0
0
000
c-
0
0
o
"
00
•0°-
,r0000
-6
oO00cc0Dcc) 0
50
100
100 x/c
PLOT 2 CASE 0441 FILE 4 .1c
0.5
y/c
0.908
- 0.642
[4
-,I
U
i
a250
.951A6
-
0
I1
I
1.1747
" 4
Al
4 PLOT 3 CASE 0!'.41 FILE .. " -I "
S.. 0.5
u/c -
.
.
1.95146
1.1747
0.908
0.642
I
d *10.0
"
0
0.2
0
0.2
0
0.2
0.2
PLOT 4 CASE fd41 FILE 4 0.5
/e
.1747
[
0.908
0 0.6/ 2
1.95146
" "
I% I"
I
• .-i
,1
0.0
•u J
0
, I
0.05
. _
!
. I
0
I.-
-.. A
.
- .- -
0.05
0
.
I
0.05
. _ . J
. I
.
0
.
.
_ . ;-
- •
0.05
-- 7/Uref
*
.
L
2.51
.
. :-. , ,"". "-..- ' . - ._..
-'; . , ". .•• •. .• .•- L . •.I•. .. . • . .
.•.
• . .4, 4 .-
•.
. "- . •.. _.. .
.
_• -'• '_•_ ---'- ". . .
71 PLOT 5 CASE 0441 FILE 4 0620.9
y/c
08
1.1747
1
1.
14
LH 0.0.
K.
• . . _ l0
00.
.
I.
.5
0 . 005 1
0
.
0.05
V /Uref
PLOT 6 CASE 0441 FILE 4
I
0.5
0.0I
:-•
0.642
0.908
1,1747
1,95146
I
I
*14
-0.02
0 0.02-0.02
,.0.02-0.02
0 0f.2-0.02
0 0.02
2!
2.52
,.--.
:.
.
. . .
. .
.
.
.
.
.
. .
.
.
.
•" •..
I ..
~DIFVUSER
.
nOWS,
!
UNSEPARATED"
Flow 0140 Casen 0141,
SEPARA.TED
DIFFUSER FLOWS, Flow 0430,
Case 0431 1A
Simpson
L.
P.
Evaluator:
.
0143
0142,
.-
SUMMARY
Several
uation of
were
any flow eval;ated
additional
by
turbulence
are available
is
well
inlet blockage, It
is
also known
procedures the
experimental calculation
but
for
been
This
(2)
addition
to the
(1) no new eval-
I
no flow that con-
or cooled
considered;
(3)
roughness,
walls, no
flow with
only
Since hot-wire and laser anemome-
there
boundary
the entr3nce
that diffuser
very
is
no reason to consider
layer was
flows
it
entry boundary
reviewer
is
by
significantly
if
conventional
the
large.
is
layers
unfortunately
thin were
consid-
depends
thickness of the entrance
flows
with measurements if
rather
performance
displacement
of diffuser
poorly
thicker
diffusers
in
nent.
calculations
methods.
two-dimensional
heated
been considered.
however,
small,
results
haq
etc.
has
agree quite well
is
evaluation
has bein made;
and I. rst
wall curvature,
on the normalized
is
that
often
entrance
where
known,
that
this
and are more Inforrative,
experiments
It
ered.
Cole.;
levcl,
with only this type of measur Only
in
initially
suppl'ed by the Organizing Co~nmittee:
tube measurements
pitot-static ter data
used
such as
effects
free-stream
high
rules
for Data Evaluation
Guidelines
tained
ground
are
not
flow.
LA
boundary-layer
displacement
thickness
Because
of
these
needed
as
test
aware
on
of any
at
-•
reasons, cases
"
for,
;uch data
for
of an equally high standard as the available small entrance-
blockage cases. This
survey
indicates
that
one
strong adverse
two-dimensional
pressure
gradient
and one flow with separation are documented well enough
low without separation
to be
used. Initially evaluation
only review
flows.
Since
checking
of
A.
data
two-dimensional brought
committee Klein for
of
diffuser
MTU
conical
attention
(Munich)
diffusers,
had his
flows
were
to
several
high-quality
a
amount
done
opinions
large
considered,
of
on available
but
later
the
axisymmetric
careful
cross-
axisymmetric
dif-
fuser data were weighed heavily.
Southern Methodist University,
Dallas,
Texas 75275.
253
i
.
.-
.
.
.
•-,•-•~~~~...............-• • • -_........................... ......
_
_
.
.•.
-•
,
•.
..
..-
'i
,
Case 0141.
A. case
This occurs
in
2
dd p/dx
2
Samuel and P.
is
many
very
a
enough
experiment
was
controlled
pressure
gradient
region,
working
section
cure
terms
of
than
19%,
and
profiles u
cases,
whereas
,
v
most
other
data
d 2 p/dx 2
and
dp/dx > 0
to
-,U7,
centerline
are
for
form of
differed
of
that
The pressure
a
by
> 0
whicV,
dp/dx >
0
and
The
than
were
of
pressure
well The
used
flexible-roof
The
flow has
separation
two-dimensional
integral 14Z.
a
few
and
the centerltne. pitot-tube
are well
days.
Hot-wire
measurements The
documeuited
obtained
of
the
side of
the
changes,
/dx
in
spectral
bat
U.
The
behave
results
balance
good
and
agreement
taps on the tunnel
and
not
measurements
floating
special
p
v-,rlocity
Pre for
with very
from a
Fluctuntions
obtained by differentiation of a smoothed dC
nature
off-centerline
surface-skin-'riction
temperature
strong
equation differed no more
The
documented.
was
p
a
the end of
traverse on either
coefficient Cp was obtained from static dC /dx
at
tunnel
term and t.,e summed momentum and pros-
those on
are
a
of
approaching
present.
less
from
few hours;
peri-d
for
is
be
the momentum
Klebanoff.
techniques
during
to
region
distribution.
The skin-friction
and techniques
during a
corrected
pressure
u spectra are presented;
data
among results.
2.5-m long
appears
indistinguishable
the
Preston-tube
it
a
by momentum balance and velocity
integrated
equipment
similar
that
commonly
, w-,
in
etreamwise
centerline.
the
were 2
hot-wire
probe
(1974).
several reasons.
but no separation
flow field was checked
of
Joubert
performed
finely
the wotking
2
for
good
practical
N.
< 0.
This with
E.
o
pressu-e-gradient were
small;
p
was
2
humidity;
d C /dx
was
curve.
p rases 0142 and 0143.
R.
Pozzorini (1976).
These measurements were made on a 6"-included-angle conical diffuser with an area ratio
of
4.
They
date according pressure applied the
probes, to
ar-
to A.
and a
shearing
stress.
are:
very
asymmetry and three
extends
well
diffuser
hot-wire
the three
determined by a
control
avoidance
of
entrance
exit),
anemometer.
which included
careful
to
thorough
diffuser
Shear
data and corrections
Cf was
different
the most
experiments
conducted
Mean velocities were measured with pitot tubes,
the pitot-static
hot-wire data,
a
probably
Klein.
of
errors
diffuser
(c)
thick
(the
Preston tube. conditions
resulting
from it.
exit),
thicknesses:
(b)
turbulence
Reynolds normal
entrance
boundzry-layer
the
and
medium
potential
core
(the is
stresses
a
and the
special
thin
potential
absent
(the ccre
over
most
P
PD
Reynolds
these data
search
Experiments were (a)
were
were applied to
Special merits of and
static-
corrections
for large turbulence
to
of
conducted potential
vanishes of
the
at
flow for core the
diffuser
length). The
low-core
should be developed,
turbulence
flow with
!,/DE -
4.5
and
-
100 mm of water
used for Case 2 since the boundary layer at the beginning of the diffuser is but still
thin,
and the poteutial core extends to Lhe difFuser
exit.
254
.
' -- - ".-.-
".•
,
. .
.
--.
, ".*.*--.
.
........... •,. ,-..........-
-..
.
. .
.*
,
..
.-
*
-
*
-
,
..
.1
• .*
"/,
.
-
K
SLE/DF_
4.5._
Case 0142. The
high-cor2
PK "PD
Pozzorini low-core turbulence flow.
turbulence
flow
(Pozzorini
Case
3)
25 mm of water should be used as Case 0143,
%ith
LBC/DE
-
7.25
and
which shows mar'ked influence of
-r-eetream turbulence.
PK
SPD
,Pd
-
PEZ
=.";#.
.
r
'M
I
LCase 0143. Case 0431.
R. L. Simpson,
Pozzorini high-core turbulence flow.
Y.-T. Chew,
B. G. Shivaprasad (1980).
This experiment was performed on the flat wooden bottom wall of a constart-width, variable-height,
converging-diverging
quantities
obtained
were
separation.
Complete
region where -tream cart
for
an
channel,
incompressible
pressure-gradient
backflow near
4.9 m long.
relief
turbulent was
not
the wall occurred all of the
Mean-flow and fluctuattnn boundary achieved time.
layer in
the
undergoing downstream
The streamwise
free-
velocity distribition was obtained with the normal hot-wire probe mounted on a that was transversed
streamwiae location, differentiatcd tion control
in
of
direcLion.
a quadratic least-squares
and evaluated the side-
two-dimensionality.
the streawwise
The
at that
location.
and top-wall skin-friction
To obtain dU /dx at a given e fit to upstream and downstream data was Active
suction and tangential
-gve
injec-
boundary layers was used to promote mean-flow terms
and the summed momentun,
pressure,
and
normal stresses terms of the integrated form of the momentum integral equation differed no more than 20%, and differed lesa than 16% over 80% of the length upstream of separation. In
The nor,•-al
regions without
stresses term was important after the beginning of separation. intermittent backflow, the flow field was surveyed %,iLh hot-wire 255
.
.
.
.
.
.
.
.
.
.
-
anemometers
stream,
v 2, tu-v,skewness,
for U, u,
and
fraction
uncertainties
flatness.
of time flow away from
the wall were obtained wtthtli
in regions where both techniques
stream end of
the separatcd
Fraction of time flow moves down-
are valid.
flow are available
estimated
Measurements at the down-
as boundary conditions
on
the flow.
w7 measurements will be available in another Project SQUID report later in 1980. ADVICE FOR FUTURE DATA-TAKERS
"Diffuser years,
with
flows
most
dimensionality, pro.ached,
Joubert
data
and
sets
insufficient
without being
uncertainty
gradient over velocity
with
in
documentation
of
and
instrumentation
are
deficiencies
The and
technology
is
of
measurements
for
of
as the
a
number
Mean-Eflow
streamwise
deficiencies.
of
three-
separation
the use of directionally
the common
better
studied
shortco-iing.
repeatability
is
ap-
pressure
insensitive
The
Samuel
and
as humanly possible for a flow without
now available
make acquisition
been
some
tbe experiments,
flow is as free of these deficiencies
separation.
have
with
Zhe skin-friction
the duration of
measurement
separation
tainted
to
overco:nL
data more
the
routine.
previous
measti-ement
Computers
can
used
bn
to eliminate the drudgery and exasperation that are encountered when a large amount of careful data are needed. Directionally ments whenever
sensitive laser anemometers
any backflow or large
should be used
spanwise
turbulence
is
for velocity measurepresent.
There
is
no
reliable way to calibrate or correct the directionally insensitive hot-wire for these effects (Simpson, 1976). It is a waste of effort to obtain hot-wire data in the presence
of backflow.
"anemometer with
these
future
data
The currently
invalid
"instantaneous flow Unfortunately By
the
their
studies,
tinct
need
"laser anemometry
such hot-wire
data.
often Such
tempt
data
and the
computors
comparisons
with hot-wire anemometers
lead
sparse amount
to
compare
to
more
of laser
their
results
confusion.
All
in the presence of a widely charging
direction should be totally rejected. laser
anemometry
time most
graduate
having produced
for
of
available
hot-wire
data obtained
master.
existence
future
is
expensive
students
to
become
use and competent
requires to use
only a small amount of useful data.
diffuser
research
some
it,
time to
they
finish
There is
the dis-
to be conducted by organizations
that use
professionally with long-term personnel.
The Rubesin et al.
(1975)
rior surface-heat-transfer
surface hot wire on a polystyrene substrate is a supe-
skin-friction gage to anything else.
It can•
be calibrated
in laminar flow and used in turbulent flow with and witho'ut pressure gradients. easy to manufacture and use,
It
is
so inexperienced graduate students who do nearly all such
experiments can use this device successfully. Mean-flow to
some
degree.
thcee-dimensionality The
size
of
the
plagui
s all separaiting turbulent
large-s. ale
256
turbulent
structurep
boundary ,omes
a
layers si.-.able
fraction
of
the
separation, iiifluenced ments
in
It
clear
is
spanwise
so no by
the side walls
that the
peripheral Huwever,
large-scale
obtained after
structures
geometry.
three-dimensional
nature
A of
flow
channel
mean flow is probable.
at
some
location
Several investigators
variation
in
downstream
of
possible--a cellular structure strongly
eliminate this problem, the
believe
but this is
that
experi-
not entirely true.
flow may be nearly
eliminated
in
an
at some titreamwise location the radial and peripheral
important
that
the
throughout
do
not
cellular
interact
with
structui.,
set.rated diffuser
the data-gathering
The pressu -- gradieiit
documented
the
of the large-scale turbulent structures approach the radius of the Then the flow structure is influenced by the geometrical constraints.
i.wo-dimensional
is
is
diffusers
axisymmetric diffuser.
Adjacent
of
two-dimensional
axisymmetric
dimensions diffuser.
width
one
another
may also
flows are
be
as
they would
produced.
clearly
Data
needed,
but
in
a
on the will
be
task has been made less laborious.
distribution strongly
pressure-gradient
influences
distribution
be
the flow development repeatable
and
so it
thoroughly
the course of an experiment.
REFERENCES
""
Pozzorini, R. (1976). "Das turbulente Str~mungsfeld in einem langen KreiskegelDiffusor." Ph.D. Dissertation 5646, Eidgen~ssischen Technischen Hochschule "ZUrich, Ed. Truninger AG, Zirich. Rubesin, H. W., A. F. Okuno, G. G. Mateer, A. Brosh (1975). "A hot-wire surface gauge for skin friction and separation detection measurements," NASA TM X-62 465. Samuel, A. E. and P. N. Joubert (1974). ingly adverse pressure gradient," J.
"A boundary layer developing Fluid Mech. 66:481-505.
Simpson, R. L. (1976). "Interpreting laser and hot-film anemometer arating boundary layor," AIAA Jou., 14:1, 124-126.
%
in
an tncreas-
signals in
a sep-
Simpson, R. L., Y.-T. Chew, and B. G. Shivaprasad (1980). "Measurements of a separating turbulent boundary layer." Project Squid Rep. SMU.4, Purdue University.
257
DISCUSSION
Flows 0140, 1.
It
was
recommended
that
Case
0141
be
0430
designated
"Boundary
layer
in
an
as
a
adverse
pressure gradient." 2.
It
3.
was suggested that Cases 0142 and 0143 be considered
(a)
as a diffuser flow of given geometry,
(b)
as a boundary layer flow using a given pressure distribution.
It
was
layer
suggested flow.
It
that is
Case
uesa
and
Peter Joubert encountered
approximations find Us Moreover,
but
2.9 m
not
be
possible
to provide
other do not
that a
normal
Joubert
and
velocity computed on this
by
the Samuel, x -
The data at
of U
will
necessary
to
compute
the computor
boundary
with details
of a
to the pressure specification.
comment was received after the 1.980 Conference:
The following additional A question concerning Moore.
0431
therefore
or
the outer flow as an alternative
streamline in
4.
either
x -
from
flow, 3.4 m
apply.
in
pitot-static
tube
stress data
are
that
locations
He notes that was
they
used
available
in
has been raised by John
show disagreement between the
the recorded
point and he confirms invesLigators
Case 0141,
values of Cp.
We have
the effect
is
where
usual
the
real and
val-
queried has been
boundary-layer
did not use the wall pressure to
to measure this quantity directly. the
data
file and can be
used to-
gether with the data for Ue to check the measured wall pressure.
(Ed.: This recommendation has not been followed since a review of the complete data set for the 1981 computations indicated sufficient boundary-layer cases are available without it.] ([Ed. (SJK): We have computed this flow successfully as a boundary-layer flow. Success, in our view, depends on appropriate modeling of a detachment zone in transitory stall, but the data are entirely adequate at least for the method given by J. Bardina, A. Lyrlo, S. J. Kline, J. H. Ferziger, and J. P. Johnston (to be published in J. Fluids Engrg.] 258
-. .,i....
___."
.
.
.
.. *
*.
-'
-
.-
•-
SPECIFICATIONS FOR COMPUTATION SIMPLE CASE/INCOMPRESSIBLE Case #0141;
Data Evaluator: A.
Data Takers:
L.
R.
Samuel and P.
Simpson
Joubert
PiCTOGIA[L SuLm4Y Date evo4. eooori
rioý o040.
1.
Sl.
0on. -DiLfuser floa. (.noopsrLoed).÷
Puib-r of
Test 1ijg
Came
co_
_ _ _1
0_
_
5![.
V or
dp/d. or
Stations Moosor4d
ProfiiCo "
_
_r_
_s
_-_ _ tlog
Iloses
Plotwa
Orint
4, Rbnel-ion
Abcis
1.0
x
use
1
Cf
x
Ordinate
Abscissa
Range/Posit ion
Cf
x
1.04 < x < 3.39 m
y
(,v/U2)
0 < y < 0.040 m
Jou o~,Plot .°.,I
2
_
tubs,
)
,
.
n_ lo_ _ _ l_ ty _
0.)Z
tro-6 •
_ 1, ch~ek".
•
A I- .-I*
oments
1.339 Comments
3 curves at
x - 1.04,
1.44,
2.38,
2.89,
1.79 m. 0 < y < 0.040 m
v/U
3
3 curves at
x -
3.39 m.
.Note
Cf
0 < y < 0.10 m
U/Ue
y
4
is
normalized
on
2 curves at
Special Instruction: the reference velocity
Uref
at
x - 2.87,
x
0,
3.40 m.
the
first
and not the local Uer
pressure tap,
Ie
259
*
.
.
.
.
-
PLOT 1 CASE 0141 FILE 4 I|"
II
0.006 0
CFC CFPT
o 0.004
CFFE
0o0
t
Cf
08
0.0020 00
x
(in)
PLOT 2 CASE 0141 FILE 25,26,27 0.04
--
YI
k
1 .A44
PLOT
. CAS
1.79
0110'LE2,6
00
0
0- 0 tt
0
0 0
S*
0.00 L1t 0
0.001
0.002 0
0.001
260
0.002 0
i
0.001
.
0.001
.
...
PLOT 3 CASE 0141 FILE 28,29,30 0.10
x
3.39
2.39
2.38
00
,,.0
~0.05
•a
0
".o
oo"
00
0
0
00
0
00 o0
*
I,
000 0
0.001
0.002
-.. 0
0
0.002
0.001
0.001
0.002
PlOT 4 CASE 0141 FILES 14,16 0.10
x - 2.87 a
-
3.40
--
' 0'
0"
008 L Yoo '..-..
0" 0
"0
0.06
0 0.04
00
40
0
-0
-0 0
0 0
0.00
-
0
1
0
o
0, 0
0
II rI
I
0
°
0.5
0.5
0
1
1
n~
--
:4
.t . ..
,
-,
>-
-,.
,.
jJ
.
:--:'
261
Da "8a FICATjj
NS FjR COMPUTATION
ENTRY CAE/INCOMPRESSIBLE Case #0142; Data Taker:
P
lO 0140.-
Data Evaluator: R.
Dotat
Pozzorini
l
rt
R.
-ak.
R.
L.
Simpson
(Low-Core Turbulence)
m+ ker ot htI ..a... t St.
on.
'Dtfffuser |Vi- (u-4parsted).'
V..~
V.locity Cam Deta laker
j
year Ni
.o.try
or _C'_'
U,
V
-2
PreF91e. -
I
Re t
C
oCor
.t
Cal 0 14, 2
oleur oico
0ee4erlel 12
12
12
12
12
*
(b
-
C."n AA&.1,6'
i
l.. a --
d
tub . 11 .t
f41.9)
4.5t Area Ratio 4A
-
C
l-s 10 1
l/d
.d io.
2 .U ,
I.
-tS~l
ca0thl Oher Mote. O r.
l.02t (]e
tIrbuL.ec4).
1;.-
0.311
1
___J
Plot
Ordinate
Abscissa
1
Cf
x
2
Cpw
Range/Position
Comments
-0.055
< x < 1.90 m
-0.055
< x < 1.90 m
_
Cpw
(p
D
pD)/
'2 r/2 ref
Ref values and P at locations •hown on sketch ?n Summary, Case 0142 al)ove. 3
U/U
r
-uv/U2
4
0 < r < D/2
2 curves at x - 0.5723 m and x = 1.813 m (Files 22, 27).
0 < r
5 curves at x - -0.055, 0.1908, 0.5723, 1.049, 1.813 m. (Files 16, 19, 22, 24, 27).
< D/2
Special Instruction: P -
,all
pressure at given x.
U, - velocity at tunnel centerline. PD'
V
Pref'
Uref are defined in summary. to Pozzorini's Case 2 with
This case refers
LE/DE
-
4.5
and
P-
D
100 mm;
see Summary.
9.
262
+',•
-•
,'
•'.
...
PLOT I CASE 0142 FILE 2 0.002
0
0.001
0.000F 0
0.5
.2
PLOT 2 CASE 0 142 FILE 2 0.6 00000-. 0 oc0oc
0.6 00 0 00 upw
0
0
0.4 ~ 0
0.0
0
o
C-0
0
1
263
i
PLOT 3 CASE 0142 FILES 22,27 x
020
o 0.5723
1.1 *0
0
0.15
I.
.
0-*
.
0 0
0
0.05
S0
0 0
T
0
0.00 i-
-
SI-
0
0.5
1
0
0.5
U/U'
--
16,19,22,24,27 0142 FILES PLOT 4 CASE ., ' 'I . .
::..
x -- 0.055 a
0.5723
0.198
1.049
1.80 3
*
020T-4i
0.150 .1I
00 0
-
I
00
".C05 r
-'b
0
,i
000
*
0
40
00
0.00'-
"0..05
0
0.005
.
.
O
0
1
+2 o
.
0.005
.
0
.
0.005
0
0. 0
'5
264
7.
...
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case 4#0143; Data Taker:
Data Evaluator:
R. L. Simpson
R. Pozzorini (High-Core Turbulence) FICTOGIAL 4RUe&J1
VI". 0140.
Oct. 9l.u.&6u r i.
Sift"On.
velocity C...
Oc.Te-.y...
T..t KI&Ioo
CP
U
01lffy$er PLowm(unisparated).e
Trk u
Profile.
te
u
'C
lt L.
C
T4s
C.. 0143 few.001l
0
C..4-A
ti..
.21 6
u
~
pl-4'ot@,s (bt.d
6
.
oXther Mated
ý cldf~ - r hg .blw) t6 re6(Feeoste)
Pei I,.
Plot
Ordinate
Abscissa
1
Cf
x
2
Cp
x pw
Range/Position
Comments
-0.055 < x < 1.90 ma -0.055 < x <.90 m
C
-
(P
-PD)l2rf~f
D)
1/
PrpwUe
Ref values. P at locations showin on sketch in Ru~oo.-ry, Case 0143 above. 3r
u/U1
4
r
-vU
~
0 < r < D/2
2 curves at x -0.5723, x -1.813 m. (Files 37, 39).
0 < r < D/2
5 curves at x - -0.055, 0.0953, 0.5723, 1.049, 1.813 m. (Files 35, 36, 37, 38, 39).
Special Instruction: P *
U,
W
wall pressure at given x. velocity at tunnel centerline.
POI Pref' Uref are defined in sui-ary. This case refetrs to Pozzorini's Case 3 wjith *
water; see Su~ary.
265
LBC /DE
=7.25
PK
PD
-25
min oF
PLOT 1 CASE 0143 FILE 28 S~~0.004
["
co o
0.003 L
CFPT CFC
Cf0 0.002
0
0.001. . •'.
,0000
r-
.
Io
.
0
0-5
in 1
1.5
2
• PLOT 2 CASE 0143 FILE 28
*
1
.
--9 c0
00
5
.
x (in)
.T
,,
.,,.
...............
.
. .
. .
.
.
. .
.,
.
.
.
...
266
.
.
"
.
I-
*
------
PLOT 3 CASE 0143 FILES 37,39 -1 -- - . - -- . -- -- - - i - - - - -
"-
-
0.20
0.5723 U
x -
0
0
1 .813
o
-1
00
.
.-
-
<0
co o
0
0
L,0
.-
•
'
,
.
'
05 -
~,0 .0 5 01
•
•-.':"
~0.0 c)_ 0 0
0.5
1
0
0.5
u/u'
PLOT-0054 CASE 0143 FILES 35,36,37,38,39 T' '1. '
--
'.'
0'20 ~0.20
i y -•
o•
i "'-•,o0.0953
0.5723
1.049
o1
,.
•:'"
.:I'
~0.05 0 1
1
1.81
*i
*,
,o
T-0
0
0
00.005
0
0 e
0.005
0
0 005
-uv/U 1
267
0
4
o
1 -
0.05
0•-
0
0.005
SPECIFICATIONS FOR COMP" ATION ENTRY CASE/INCOK4PRESSIBLE Data E%,'uator:
Case 00431; Data Taker:
R. L. Simpson
R. Simpson, Y.-T. Chew, B. G. Shivaprasad ViC14IAL. SmitkIity
Ptoe
0430.
I.
Qstd llvoloeto:
Stpoo.
'DIiffuser
Flow (.oparat.4).
Wimsberof IZOtatOSe Pfisugoqd
~
Velocit
-
Profiles
Ur1ules
dIP/4.
Test sit
Case
C.-
te
or
0411
.r
Co.&411
IJ.1.
2
I-
21 ii P.1y le.C
\
"
-W -
1
1
e
' 6
iI
it,
I
I
4$
lit
i.
tb
li ttio 11
Sis.
I
Ordinate
I
Cf
.O7 I0D
-tOO
Ie
.o
x>0
Plot
~
r
(0
Abscissa
Range/Position
x
0.905 < x < 4.34 m
MV/U 2
0 < y ( s5
o
,~~..on.
O ,* tnio of nto -te-do-,stro....
for. I I
f hO..
-4
of &Ar. " tCho upperti
of- Posiio. e a-
Comments
3 curves at 3.972 m.
x
2.673, 3.327,
3
y
U/U0
full channel
5 curves at x 1.632, 2.197, 2.673, 3.01, 3.286 m.
4
y
U/U0
fuil channel
5 curves at x -3.416. 3.680, 3.972, 4.430 m.
3.524,
5 curves at x -1.632, 2.673, 3.01, 3.286 m.
2.700,
full channel
5.;uvvc at x -3.416, 3.680, 3.972, 4.430 m.
3.524,
full channel
5 curves at x -3.416, 3.524, 3.680, 3.972, 4.430 m. yU fraction of time floý.- moves in downstream direction.
*5
y
Uýfull
6
y
-uv
7
y
channel
YiU
Special Instructions: I.
In Plot 1, indicate location of comnputed
2.
Start computations at
x
-
Cf. - 0
0.805 m; plot from
by an arrow.
x - 0.905 m.
x
-0
is step which
trips boundary layer; see sketch I below. 3.
This
flow can
plus matching)
be computed
parabolically
or elliptically
(by
as desired by 268
inviscid
core and boundary
computor groups.
If the
layers flow
is
done elliptically, the laser data at 4.34 mn and the hot-wire data at 4.31 m can
4 1
he
used for downstream data; if these data 3re so used, the±y should be specially
~marked
on any output.
effective streamline near the upper wall as a boundary See data attached to this specification as Table 1. Or,
Take the channel.
6(1)
Computorfi using paraboll.c methods can: for
the
(ii) Compute houndary layer on upper wall. The baois employed should be clearly stated in any event. 4. CfL
Cf
baapd on Ludwieg-Tillman correlation.
4.Cf---------
Sktc
I
ieiwshmtco
th
10 ice.Nt
wal an
tetscin
Ma
bafepaeusra
pe
e
rdiviintn
ofbuitlain
onaylae
otos
cls
edeo
btom
es
'
00enran1 0.8
1
1-a334
(Cs 04
1)
17
2.223 0.503 0.854 310118
0.2042 0.2355 0.2535 0.2754
3.230 1.887
0.3881 0.1343
3.681
0.23935
3.973
0.4565
4.341
0.5149
Y(x) calculated by: 1J_(x) where 6
[Y(,)
6*]
=
'
constant
is the test wall displacement thickness.
rI 269
I
i
PLOT I CASE 0431 FILE 2
S
~0.006 0.004
-
0.002
0.004
0
12
3
x (in)
PLOTll 2' CAS E 0431 FILE1 1
2.673
1392
U3.327
0.0
o2
1135
0
-
PLOT 3 CASE 0431 FILES 10,14,17,18,30
0.10
3.286
3.01
2.673
2.197
1.632 a
IJb
I
I
7
°
0
o
0.00
0
0
00
0.00
0
2
020
20
-0 200
0
o
U/jo
0.3,
i
1
-3.416
0
00 0
.
0
00
0
,)
0. 0
00
0
-
.-
02
o
0
,,
-
0 32-36 FILES 0 C AS:E 0431 PLOT 0 04 "-rO I ~ o 4.430 3.0680 •3,072. m - ' 3.524 _ -
2
40
0
0.-
00
-
'
0,-
,0
'.
0
0
0
.
I
.
.'-'".
-
--
PLOT 5 CASE 0431 FILES 10,13,18,27,30
0.04
o
2.700
32
o
1t
"
1-
0
0
0 .03 ,_7 0.023 -°
3.286
3.01 1
2.673
-
T
0
"-. I.,4
..-i,
° °
t-
t .1
00:
0
0.02
0
000+
-0
4•
0
4
0
0
0
0
00 1 2 3
0
1 2 3
0
0
-
1 2 3
0
3
1 2
0
3
1 2 u2
PLOT 6 CASE 0431 F'LES 32- 306 I.-,.
I
-
0.3-
0.
0.2-
2
0
3.680
3.526
3.416 •
3,972
i
4,430 4.43
3.97
T
T 0
S0
0 . O0!
0
0 0
0 0
4.
,
0.0
0 0
I
0
1
?
0 0
0 0 0
x0...
0
*
0 0
-UV 272
..
0--
-
o 4-
-'I, 0
.
_
o 0_
__
-
0 0
-
.•
I..
PLOT 7 CASE 0431 FILES 32-36 0.3
x - 3.416 .'
3.680
3.524
3.972
.
-
0
00
0.2
0j
0
0.2
1
_
,.-
0 0
ol
0 Il0
--
0j
0
0,0
0
0
o0
0,
0'01
0
j 0
0.1
S
1
0
0
0
.
. . . . . . .- . .
.
..
0
.
-. . . . . . . .o ..
-fo
0
0
00~I,
...
.
273
..
.
"-_.-........
SESSION V!
Chairman:
E. Reshotko]
Technical Recorders: R. Westphal
D. J. CockrellI*
Flow 0420
K
Predictive Cases: Flow 0110 and Flow 0420
Flow 9000
.4
274
STEP FLOW
BACKWARD-FACING
Flow 0420 Case 0421 Evaluators:
J.
K.
Eaton and J.
P.
Johnston
SUMMARY
Data
sets
for
subsonic,
steps have been evaluated dures. More
This
report
summarizes
detailed discussions of
Johnston (1980a
turbulhnt
flows
over
for their suitability
the
the
two-dimensional
as test
procedures
atd
backward-facing
cases for computational results
of
the
data
results of the data review may be found
proce-
evaluation. in
Eaton and
and b).
SELECTION CRITERIA The selection instrumentation, data,
and (4)
(2)
are grouped into four general categories:
adequacy
agreement
A
(1)
criteria
laser
of
the
experimental
facility,
(3)
anemometer
or
a
pulsed-wire in
throughflow times should be used for all
anemometer
quantities
The flow must be two-dimensional
this
is
than
10 and
Two-dimensionality
not possible, the
layer
at
Reynolds
number
of
The
initial
should
in
be
of
the
uniformity
at
least
of
should
separation
1000.
should
The
order
flow
fully
used
for mean
Averaging times of 2000-5000
to allow accurate comparison with by
direct
momentum
(step span/step height)
the
be
be
Hot-wire anemometers
to minimize scatter.
checked
the step aspect ratio
spanwise
boundary
completeness
the separated flow zone.
and pitot tubes may be used downstream of reattachment.
computations.
adequacy of
of the turbulence data with common trends.
velocity and turbulence measurements
(2)
(I)
should
be
turbulent
free-stream
a
turbulence
If
should be greater
carefully
with
balance.
checked.
momentum
level
The
thickness
should
be
low,
0(0.1%). (3)
and turbulence of separated
condition
profiles
flow,
in
must
should include
and •r.
Downstream of reattachment,
detailed
to obtain the
(4)
as well
by
the
mean-velocity
Within the zone U,
as well as u",
the mean-velocity profiles should be sufficiently
as mean-velocity
plot.
profiles
for
Wall static-pressure the boundary
data
layer on the
any).
The turbulence
trend exhibited
detailed
profiles of mean velocity
skin friction from a Clauser
wall opposite the step (if
including
the boundary layer upstream of separation.
the data
should be available,
specified,
be
intensity and Reynolds shear stress should bulk
of
the
existing
data
sets.
They
follow the
should
both
common
increase
*I
Dept.
of Mech. Eng.,
Stanford University,
Stanford, CA
94305.
275
.
..
.
.. .
.... .
.. ...
..
..
.
.
downstream
of the
reattachment.
separation
point and then rapidly decay,
The peak value of the Reynolds shear stress,
mately 0.011 ± 0.002.
beginning -uv/Uo
somewhere
near
should be approxi-
The peak values of u2/U2 should be approximately 0.04 ± 0.005.
These values have been established using the available laser-anemometer data. SELECTED DATA SETS Unfortunctely, listed above.
none of the available data acts met all of the selection criteria
The data set of Kim et al.
step test case because rently
available
it
data
Tropea and Durst (1980), future.
meets more
set.
(1978)
was selected as the backward-facing-
of the selection criteria
Several
new
data
sets
by Eaton
and Kuehn and Seegmiller (1980)
than any other cur-
and
Johnston
(1980c),
will be available in the near
These data sets appear to promise more accurate turbulence data than are cur-
rently available.
However,
3ubject to external review before they can
they must be
qualify as legitimate test cases. The
experiment
dimensional
of
Kim
excellent
epanwise
(1978)
al.
sudden expansion (see
and has several advantageous (2)
et
Fig.
I).
features:
uniformity,
(I) (3)
and
was
conducted
in
The
experiment
was very well documented
a
single-sided,
two-
a turbulent boundary layer at separation, compleLe
initial and boundary-condition
specifications. The data set does not meet the selection criterion specified under "Instrumentation."
The mean-velocity profiles were measured with pitot tubes rather than the pre-
ferred instruments.
However,
the measurements are reasonably accurate,
the reattachment region (6 < x/H < 8).
except within
The mean-velocity data can be confidently used
for comparison with computer calculations in all other regions of the flow. The only really serious drawback to this experiment is
that the turbulence quan-
tities were measured with an x-array hot wire. The mayimum values of the shear stress (-uv) and the normal stresses are substantially lower than those measured with laseranemometer Fig. 2).
or
pulsed-wire
techniques
in
other
bazkward-facing-step
experiments
(see
The reviewers feel that the turbulence data within the separated shear layer
should therefore
not be used
been included
the compilation.
in
lated turbulent line from Fig.
shear-stress
for comparison levels
These data have not
to experimental data should use the "beat guess"
2.
The dat• set of Chandrauda (1975) in the data library. backward-facing-step
"unsuitable for
with calculations.
Computors who would like to compare their calcu-
It
has also been selected for eventual compilation
contains the only known measurements of triple products in a
flow.
The
boundary layer
at
separation
is
laminar,
making
it
use at the 1981 meeting.
276
..•:22"~i21• .•222ii 2 i112••2"••ii2ii.i
• ii..i .,i1 i : J2 i'2
l2
•
- li• 2i . . :-•
i. .
.
. _. ..
-.
-
.
K RECOMMENDATIONS FOR FUTURE WORK The reattachment
process
is
still
relatively poorly understood,
number of
experiments
on the backward-facing-step
the
of
instruments
lack
suitable
instruments supply all
are
available,
accurate
data
of the criteria The
should Kuehn
checking
of
system
investigated.
and
Seegmiller
subject.
or
laid out in
effect
be
for
one
for
use
two
in
The biggest
reattaching
careful
flow
flow.
flows.
experiments
calculations.
despite the large problem Now
should
These
that
be
suitable
undertaken
experiments
4
,a been
should
to
meet
Eaton and Johnston (1980a).
geometry and A number
of
at NASA-Ames
streamwise
studies
Research
of
pressure
gradient
on
reattachment
this effect have already
Center
are
continuing
Their preliminary work pointed out the substantial
their
effect
commenced.
work
on this
of pressure
gradi-
Additional studies are being undertaken by Tropea and Durst at the University of
ent.
Karlsruhe
and,
in
our laboratory,
by Westphal,
Eaton,
and Johnston,
and by Pronchick
and Kline. Systematic
studies
of
layer and the effect of
the
effect
the free-stream
of these effects appears to be as Further
experiments
reattachment
zone.
are
is
separated is
tion
of
that
the
skin-friction reported
by
needed
turbulence
on
explained.
the
In
near-wall
flow region.
negligible
suggest
thickness
of
the
the
separating
boundary
level may also be useful.
evolution
Neither
gradient.
of
flow
structure
within
the
turbulence energy wlthir& the reattachment
zone
particular,
many
the
two-stage decay
noted
in
not well understood.
Measurements the
the
important aa the pressure
The rapid decay of
has not been adequately experiments
of
in
Many
and
computational
the
skin
friction
Chandrsuda
in
is
actually
the
(1975).
skin
However,
quite
reversed-flow
region, of
that
These other skin
are than
be made
the
our own recent
large.
Further measurements
data and to understand
friction should
procedures assume
the reversed-flow region.
measurements
check the available
velocity
friction
skin fric-
measurements
the a
in
I
only known
single are
point
needed
to
the variation of skin friction with various
2-
flow parameters.
further
of
cause
The
low-frequency
investigated.
Such
Eaton and Johnston (1980b) 1975).
Large-scale,
of
mctions
motions
have
reattaching
the
been
observed
and Tropea and Durst (1980),
low-frequency
in
shear sowe
but not in
should
layer
experiments others
be
(e.g.,
(Chandrsuda,
motions may be of considerable technological
impor-
tance.
277
-...
. . . ....
-o..
- .
.
-
• .•
.,
'
-
.,
,
• - .
-
.- ..
..
-.
.
. ...
.
•
.
*..-
..
. ..- -.
. .- .- •
-
.
1 REFERENCES Chandrsuda, C. (1975). "A reattaching turbulent shear layer in incompressible flow," Ph.D. thesis, Dept. of Aeronautics, Imperial College of Science and Technology, London, SW7 2BY. Eaton, J. K., and J. P. Johnston (1980a). "An evaluation of data for the backwardfacing-step flow," prepared for the 1980-81 Stanford Conference on Complex Turbulent Flows. Eaton, J. K., and J. P. Johnston (1980b). turbulent-flow reattachment," Paper No. dynamics Conference, Snowmass, Colorado. Eaton.
"A review of research 80-1438, AIM 13th Fluid
on subsonic and Plasma-
J. K.,
and J. P. Johnston (1980c). "Turbulent flow reattachment: an experiof the flow and structure behind a backward-facing step," Report MD39, Dept. of Mech. Eng., Stanford University, Stanford, California.
"mental study
Kim, J., S. J. Kline, and J. P. Johnston (1978). "Inv'stigation of separntion reattachment of a turbulent shear layer: flow over a backward-facing step," port MD-37, Dept. of Mech. Eng., Stanford University, Stanford, California. Kuehn,
D.,
Tropea,
and H. Seegmiller (1980).
C.,
and F. Durst (1980).
and Re-
Private communication.
Private communication.
278
278
•'
.
•.. .-...
.
-,-
..
-.
.
.....
.. *.-
. . .--.
.-..
.
."
- ". .
.
.
2.
i.
,
i-
i
~
Reference oint x/H
= -4
/V
'
U
0
ti
Figure 1.
UI
Test section configuration of Kim et al. H m 3.81 cm; area ratio 1.5.
(1978).
Evaluators' best estimate curve
C• C.7J
0
7
V
vo
0
1 0,
i
00
0
2~
V.V 001
o .41
IIII'*
-o
-4
-2
1-
.-
0
2
6
(x-xR)/H
Figure 2.
Reynolds shear-stress data and "best guess- line for experiment of Kim et al. (1978). o Baker; <> Chandrsuda; 0 Kim et al.; 0 Smyth; J Tropes and Durst.
.4
279
.
...-.-...-.-
..
.
.
V
Kuehn and Seagmiller;
!,"j DISCUSSION
Flow 0420
'.
F.
Durst
and C. Tropea (Karlsruhe)
now available
noted that
for the backward-facing
laser-doppler anemometer
data are
step and request a wording change in the
"evaluation report, "2.
C. Tropea questioned the selection of the
x/h
-
4
station as the only station
in the separated region where comparisons are requested.
He also suggested
the[
mean normal velocity as a sensitive and desirable comparison within the separated region. 3.
E.
Sutton showed the susceptibility
P.
bance using
some
of sudden expansions
of his own data as example.
separating layer; it
These
to upstream distur-
data were
for a laminar
was accepted that higher Reynolds number separating boundary
layers would not be as susceptible to disturbance effects in the initial region. 4.
No changes were recommended tc the specification
280
--
•
-'280
for Case 0421.
SPECIFICATIONS FOR COM.PUTATION CENTRAL, ENTRY CASE/INCOMPRESSIBLE Case 10421;
Data Evaluators:
Data Takers:
J. K. Eaton and J. P. Johnston
J. Kim, S. Kline, and J. Johnston FICYOSIAL SI.3*fl
72ev 0410.
Det8 IVslatWre
kmr-.i
&MAJ. v.JQset0..
J. bet.
1.- ty
wrlw.1 Sta
o
---.
h.
Fl.
-. e. .s t5oo
-C4.
TestItsof
Camea
2
C,
-T
C6. I
0V2 U.1Am1t.te1
"so-- T
i K11.4 e.
as
-
r--
meet.1
b
T
,(~*
.
ih9r.4c 0.3
I
Plot
Ordinate
1
Abscissa
Range/Position
xIH
-4 < x/Il < 16
Cpwi
LUevr
s..o I4.te
Conzments P~ot on step-w.all side. (Opposite side optional.)
-Uvma 1 /U2
2
CX-XR)/H
-10 < (X-XR)/H < 10
*uma maximum
uv from
profile at given x. 3
y/lI
U/U0
full channel
At
x/H
4
-_VMIU2
yIH
full channel
At
x/H
-5.33,
8.00, 13.33.
7.66, 10.3, 15.67.
Special Instructions:
"wall 2.
Take
Of 3.
-R
Po tCPwell 1/2 PU2
P0 so pressure at
U
-
x/H
-4
fre .-stream velr,ýity at
x/U
-4
location of reattachment as computed by your progrdm, report value
XR.
Plot 2 shows data frora the file on Case 0421 for (u-v)Mrax/, the best
estimate drawn through all acceptable data for
from Fig. 2 above.
281
.
The full line shows 2 -uv a/Uo. it is taken
"PLOT 1 CASE 0421 FILES 2-3 0
000?8 0
0
00
0.0 0.3.
0
0
•
01
0
0-0
.
cpsw
00
0 a
0 "
i
0
heel
10
ae
C
y
"*
20
x/H PLOT2& CASE 0421 FILES 27-32 r
x/ 0.005
"
i
•A1
; •a - ?,
h
',282
0
0 000 -10
--
"0
PLOT 3 CASE 0421 FILES 19,22,25
00
"0 00
0
y,/H
I
5 S3
--
0_ 00
.
.3
o
0-
0
0
I0,
01
0
oO
r•x/-.50 '---I
C
I
80
1333
-
<>-I-"
°
o--
1
0
10
0--
U/U0o "PLOT4 CASE 0421 FILES 28,30,32
0,0100
00
0-00
00
./-
10
0
. ---
--
.
. -.
.
.
-.--.------.-..-
.
.
.
.
.
.
.
0
2
0
.0
.
.
.
283
.
.
.
.
.
.
.
.
.
.
.
AN OVERVIEW OF THE PREDICTIVE TEST CASES by John K.
One of tive
the unique features
test cases"
etries
(or
ordinary
test
data)
case.
experiments
have
predictions
at
of the 1980-81 Conference is
for several classes
boundary
will
be
However,
of flows.
supplied
the
1981 meeting.
Initial
for
First,
are
two
computational
problems.
Users
some way of
of
of
Therefore,
any
successful
for
mechanics
the available
computational predictive
the is
data
now
procedures
base.
addition being
of
expirimencal K.
the
work
Eito' aied
periments are
experimenters suggested by
S.
for J.
were
The
test
practical
test
must have
that are be-
cases will
from the current
variouc
to
the
test
Stanford
data
teat the
base.
Sec-
considerably more "file
test of scope.
cases
is
University.
laboratories
researchers
have conaiderable
experience
being
coordinated
However,
throughout
by
the
in
making
the
actual ex-
the world.
Organizing
Some of
Committee.
the type
most
by
The
of measurerients
The remainder of the predictive test cases are
whoie timetables hqppen to mesh well with the -:onference schedule.
the experiments
for
flow
cases.
are currently in
the preliminary staget.
The bulk of the
experimental data vill be obtained during the period between the two conferences. timetable
the
engineering
industrial concerns)
predictive
predictive
the Organ'.zing Committee.
Most of
to
Some taodels may .equire
the
at
suggest-d
already
"ongoing experiments
for an
since
of the
predictive
applied
to extrapolate
Kline At
being conducted
experiments
calculation
the
tuning" than others; predictive cases will be a significant
J.
be
be supplied
test cases will help the research community to assess the usable
scope of var.ous turbulence models.
Profs.
would
their applicabillty to complex-flow configurations
ondly,
The
they
procedure.
computat'.onal procedures (primarily
ability of the
as
The experimental data will be presented with the
reasons
fluid
assessing
the range
yr-vA
major
"predic-
conditions and boundary geom.-
data will not
field will require a truly predictive computational There
the inclusion of
these cases
experimental
not been completed.
the
Eaton*
of
the
experiments
is
cuch
that
first publish their results in the summer of 1981.
the
experimenters
However,
would
The
probably
they have agreed to with-
hold publicption or private communication of any resulte until the 1981 conferenc,. The predictive
"metric Sstep
inlet
flow;
ilow;
iii,
*"
and v)
[.
specifications.
"Asst.
a
a
transonic
Professor,
cases ii)
includc:
four
diffucer
kinds flow;
i)
developing
)f
geometric
iv)
airfoil experiment.
a
flow in
a square
modification
shock-boundary
layer
of
duct with bn asymthe
backward-ficcing
interaction
Details of the cases are given in
experiment; the attached
They are mostly perturbations of the existing test cases.
Dept.
of M4cch. Engr.
Stanford University,
Stanford,
Therefore,
Ca
94305.
,..
-
284
..
..
.• •, •_.
• . .:
•
•
k
-= •
-.
:
_
=-
•
. -.
I T:--
: '
i'•
'
-
-- .
. -.
-
.
.
.
•
:.
the numerical procedures and turbulence models should not require large changes. cannot
guarantee
that useful data sets will be obtained for these flows
the 1981 meeting. vative
It
timetables.
appears that most if
.
We
in time
for
the experiments have set reasonably conser-
We can reasonably expect
to obtain useful data for at least one-
half of the cases in time for the 1981 meeting. One major problem is
that the experimental data will not be available for public
scrutiny prior to its use at the 1981 conference.
There is a danger that undue impor-
tance will be attached to a data set which may be highly inaccurate.
Researchers
in
complex turbulent flows frequently encounter unexpected measurement difficulties or uncontrolled flow disturbances. We are taking several precautions to try to avoid usl.ng
data which! are affected
being conducted by
researchers
by such problemq.
First of all,
with considerable experience.
the experiments
are
The experimenters have
all previously made measurements in flows similar to their predictive test case.
Fec-
ondly, by showing the experimental plans prior to the acquisition of data, we hope to obtain suggestions, caution,
and guidance from other conference participants.
As an added pre-
data will be repeated in two labs for Case 0422.
The
predictive
test
case
data will all be reviewed
prior to
the 1981 meeting.
The review uill be similar to the evaluation of the regular test cases which was done for the 1980 conference. 1981 meeting. ted.
In
Any data set the Evaluation Committee deems inadequate will be rejec-
addition,
progresses.
Any problems with a given data set will be repurted at the
one knowledgeable
researcher will
This will allow the experimenter
oversee
to rectify
the
experimcnt
as
it
problems before he has com-
pleted the experiment. We hope that with th,:.e precautions we will be able to supply new data sets which are useful for checking computational methods. PROCEDURES The computors were supplied with the boundary geometry and detailed initial conditions
for
four predictive
cases
(Pl to P4)
in
January
1981.
The
computors are listed in the Appendix to this summary. LIST OF PREDICTIVE TEST CASES
.~
Case 0113 (Pl).
Asymmetric Flow in a Square Duct
Case 0422_(P2).
Backward-Facing Step:
Variable Opposite-Wall Angle
Case 0423 (P3).
Backward-Facing Step:
Turned Flow Passage
Case 0424_P4).
Backward-Facing Step:
Variable Area Ratio
Case 1. Case 6.
Flow in a Planar Diffuser with Downstream Tailpipe Shock-Boundary Layer Interaction
285
instructions
to
.
APPENDIX Instructions
FORMAT,
to Computors Regarding Predictive (Ases
TAPE ORGANIZATION
Since we will
be
printing
results
format and tape organization.
standard 1.
Follow the precise order of file
2. 3.
Report N wherever requested. Format using nE13.6 (n <_6).
4.
Use
9-track,
1600 bita Record
odd-parity,
to us
80 bytes;
separately in
the tapes,
is
importa.nt
that you ulie
labeling indicated.
to
unlabeled
EBCDIC code.
tape
Record
100 record6 per block;
wi'iting,
it
Please:
phase-encoded,
per inch according
length:
from
written at
format:
blocksize
and at he~ad of tape,
-
a
fixed
density
of
and blocked.
8000 bytes.
Report
the full details of formatting
and tape organizatior. Since supplied ealls
for
are
these
apart the
from
p:e6ictive
initial
creatior
cases,
conditions. of
an
appropriate
no
detailed
In
each
experimental
predictive
number
of
case
computor
data the
output
are
being
specif'cation data
fi.les
as
following format:
binary or trinary arrays in accordance with the
FORM OF OUTPUT DATA Please
note
dimensional.
that
Please
all
output
d., ta
report on tape
in
requested
in
the
non-dimensional
predictive
caseý2
form using the
are
non-
nortmalizations
specified so that shifts in units or normaliration will not ', necer,sary. Since we will need to produce output plots at Stanford on short turn-around times with limited personnel, We
will need
these details ore important to the evaluation of ycur results.
to have
the
tapes
at
Stanford by
15
July 1981
In
order to
compile
and disseminate results before the Setember meeting.
.4
.4
286
i . ., ' . .. . -
.
. -
-.
.- ...
.-
• .° .
.. .
-.
.
.
•
,. -
..
- , . • ... . .. . .. . . . . . . . . . ...... . . . . .. ... .. ...
ASYMMETRIC FLOW IN A SQUARE DUCT Flow 0110
-
Case 0113 (P1) Description by John K.
Eaton
4
"-.
SUMARY
*:
GENERAL 1 EATURES
"In
Lhis
test
smooth-walled
case,
square
a
duct
of two intersecting,
four
square
"boundary duct -
flow
(x'/D'
-
and
new
0) which
Sdownstream
of nals)
passages.
which
the
boundary
along
leading
edge
iq
at
x/D
condition (Reb
-
72,
UbD/v
-
in
will
inserted
of
each plate
inlet
(x/D
consists 0)
=
at
cruciform
walls.
The
symmetric
about
the
of
edge
and the
and duct
of
along
the
inter4ctions
but are
the
cruciform
uhich
corner bisectors
of the cruciform,
form
well-developed
which continue
leading
a
and has a
is 0.025D,
The cruciform
passage
into
cruciform consists
each of which spans the duct
each
locally
be
The
1.
init•iCed
the are
Fig.
1.5 degrees.
square du(
intersect the axial centerline
the other corner bisectors. positioned
a,
withir,
layers
develop
shown
The thickness
Flow
at the
as
(cruciform)
plates,
leading edge,
layers initiated
walls,
flat
leading edge.
wedge half-angle of each
insert
and positioned
smooth-walled
symmetric wedge-shaped
*
cross--shaped
occur
(diago-
asymmetric about
Data will be taken with the leading edge of the cruciform as
shown
in
Fig.
a
1, for
high
Reynolds
number
operating
2.5 x 10).
SPECIFICATION OF INITIAL CONDITIONS AND COMPUTATIONAL RANGE Computations potential-type,
uniform mean
ifying
U -
Ub,
lations
be
zero.
the when
interval
should be started
V -
0,
0
<
x/D
x/D > 72 (x'/D
is
at
used,
x/D -
flow development < 72,
> 0) in
with order
The computatitns
ciform and duct. type code
flow can be assumed.
W - 0
Local
at the inlet of the square duct
0
the
an appropriate to predict can be
which corresponds
to
turbulence-related
square duct change
flow in
in
should the
x'/D'
streamwise
be
- 24.6 location
over
conditions
formed by if
corre-
computed
boundary
the passages
terminated at the last
0) 0 where a
This condition corresponds to spec-
and letting all
in
(x/D
the cru-
a parabolic-
where data will
be taken.
287
.•
.''..'',.''••'
"...'.....
';.
"
.
.
.'.'.'
..
•
•"
.
"
,
"
"•*
-.
".
"."
"
"
"
it)
wt
-,4
ir-44
0~d
(A
CC
0
Ab-4
r-. *~
Li.
288
>
.'. DISCUSSION
Case 0113 (P1) E.
P.
Sutton raised the question of need for rounding plate leading edge.
cussion led
to general
agreement
(J.
P.
Johnston,
F.
Gessner)
undesirable in view of laminar flow results and that, at worst, would only cause
that rounding
Dismay be
the sharp leading edge
very short, occasional separation regions which would be practically
unimportant. J.
Hunt suggested
effect of the
that changes
to the turbulence
structure may be an important
.rucifor-m.
I Greber suggested the need to specify some type of vector output,
possibly con-
tour plots. E.
Reshotko noted the necessity to ensure that the foir flow channels within the
cruciform are independent by adjusting the downstream pressure. After discussion,
there was general agreement that the current cruciform blockage
-7-
is acceptable and the 3* leading cage is adequate. J.
Hunt and D. J.
Cockrell recommended flow visualization,
if
possible,
to ensure
complete flow documentation.
i--
289
289-
,
.--
PREDICTIVE CASE $V1CIFICATIONS
Coordinator:
Case f0113 (PI);
File
I
Independent Dependent Variable(s) Variable(s) (Output) (Label)
FOR COMPUTATIUN
J.
K. Eaton
Range of Independent Variable(s); Locations
of points 1-55, For each of files PI-9, create a with labels I
70
For location see Fig. 2. PI-i through binary array
70
output values for variables Use file numbers indicated.
PI-I
1-55
U/Ub
at x/D = 70
Pi-2
1-55
V/Ub
at x/D
-
Comments
through 55 and associated
Pl-3
at x/D
W/Ub
1-55
-
indicated.
P1-4
at x/D
u2/U2
1-55
70
2
70
P1-5
1-55
v2 fub
at x/D
-
70
P1-6
1-55
w 2 /Ub
at x/D -
70
Pl-7
1-55
uv/Ub
at x/D
70
P1-8
1-55
Uw/Ub
at x/D
P1-9
1-55
Uat
PI-10
1-N
y/D, z/D
locating points for isotach U/Uc - 0.70 D 0specifying
P1-iI
1-N
y/D, z/D
locating points
at x/
b
-
70 70
-
N for each fL'le irn writing and See at head of file on tape.
instruction 3.
for isotach U/Uc
For each of files P1-10 through P1-14, create a 3-element array with labels 1-N for N points the given isotach location. Report the value of
0.80
-
x/D -70 PI-12
y/D, z/D
1-N
locating points for Isotaeh 0.85 U/Uc
x/D
-
70
290
S.. . i¢ •."J:?-l•:{'.
. . :-. • - .-: : ' , ::•: -. .,:?~-
:
"
...- .
.
- --.. i - / .
.
I .
---.-
.
. . ," "2--:1"',1.1 ;,'
.
.
"'
: 'i - • . :
Independent Dependent Variable(c) V'riablc(s) (Label) (Output)
Fil: . PI-13
I-N
y/D,
Range of Independent Variable(s); Locations
z/D
Comments
locating points for isotach 0.90
U/Ut -
x/D - 70 PI-14
1-N
y/D,
z/D
locating points for isotach U/Uc - 0.95 x/D - 70
z/a
P1-15
w
0 < z/a < 1 x/D
PE-16
I-N ___
P1-17 -_
Pi-18
y'/a, z'Ia
_
_
1-N
1-N
value of N in writing and at head of file.
U/Umax " 0.80
For each of files Pl-16 through P1-27, cretes a 3-element acrayl. with, labels 1-N specifying
y'/a, z'/a __._
_
y'/a, z'/a
y'/a, z'/a
tape.
8"
__x'/D'
the
given isotach location. Report the value of N for each file in writing and at head of file on
U/Umax - 0.85 8.2 -
L
U/Umax - 0.90
"x'/D' Pl-19
70
-
___________________________________
1-N _
For create Report a binary arrayfile of P1-15, N elements.
- 6.2
U/USax - 0.95
x' /D' - 8.2 PI-20
I-N
y'/a, z'/a
U/Ueax
0.80 " 16.4
x't/D' P1-21
-P1-22
1-N
1-N
y'/a,
y'/a,
z'/a
z'/a
U/Uax - 0.85 x'ID'
16.4
i/Uax-
0.90
-'/D'
Pl-23
t-,q
y'/a, z'/a
U/Umax x1'/D'
PI-24
1-N
y'/a, z'/a
-
16.4
0.95 - 16.4
U/Ux - 0.80
x'/D' Pl-25
1-N
y'/a, z'/a
24.6
U/Umax " 0.85 x'/D'
- 24.6 291
•... :, . . . ... . ... . . .. . :.:. . . ,... .: . '- . .. : :- . . : - . :- -:... .
...
..
. .
..
.-..
Fi,
I Pl-26
Tndependpnt Detpendent Variable(s) Variable(s) (Output) (Label) 1-N
Rangc of Tndependent Variable(s); Locations
y'/a, z'Ia
-/ua 0.90
X
Pl-27
1-N
-D
P1-29
24.6
0 < x'/D' < 25
'D
y/a'
U/b.0
< yt /a' < I
x'ID' PI-30
Y /a'
U/Ub~m
8.2
-
0 < y'/a' < 1 -tD
i'1-31
y Val
24.6
-/mx 09
y'/a, z'/a x'/D'
Pl-268
U/tlb,m
16.4
0 < y'/a' < 1. 24.6
x/ -
P1-32
y /a'
V/Ub,.
0 < y'/a' < 1
P1-33
y'/al
V,/LUb.
0 < y'/a' < 1 -16.4
P1-34
IU~
y I/at
0 < y'Ia' < x/t- 24.6
2
P135 y'a
2
0 < y'/a' <~ 1 x/ -
P1-36
y'/al
u2 / 2
8.2
0 < y'Ia' < 1 x/-16.4
PI-37
y /a'
i1-~~ ya'
U
2 2 /bm0
v
2
Comments
< y'/a' < 1 -'D 24.6 0 < y'/a
<~ I
x/'- 8.2
292
For filc P1-25, cre~ate an aci 3,, of N binary elements with labels of x'/D' showing values R~epurt the valueof N of C. for 9ach file in writing and at head of file. For each of files P1-29 through P1-49, create a btnar> array of N elements with labels of y'/a'. Report the value of N for each file in writing and at head of file on tape.
File # P2-39
Independent Dependent Variahle(n) Varishle(s) (Label) (Output)
Pl-39 y'/a'
V v 2 /U 2 ,
Range of Independent Variable(s); Locations
Pl-40
v 2 /U blm 2
y'/a'
-
y'/a'
--ý-V/Ubm
< I -24.6
0 < y'/a'
_<
x'/D'
Pl-42
y'/a'I
-V/UbIm
y'/a'
•-uv/Ubm
0 < y'Ia'
Pl-44
y'/a
U
y/a'
-lUI,
-
y'/a
< I
-
8.2 < 1
0 < y'/a'
-v/Ub M
- 16.4
0 < y'/a x'/D'-
P1-47
y'a
KI2
Pl-48
y'/at
K
'
< 1 24.6
0 < yia'
< 1 -
x'/D' ,
1
24.6
0 < y'/a'
x'/D' Pl-46
16.4
0 < y'la' <
x'ID' P1-45
< I
-
Y'/D'
1
8.2
-
x'ID' PI-43
16.4
0 <-- y'/a'
x'ID' Pl-41
!b
01< y//a X'/D'
Comments
8.2
0 < y'/a' x'/D'
< 1 - 16.4 2"
PI-49
y'/aI
K/U2bm
P1-50
z/D'
Twy/Tw'y
0 < z/D' x'/D' -
< i 8.2
Pl-51
z/D'
TwIyTwTy
0 < z/D'
< I
0 < y'/a' x'/D'
< 1 -
x'/D' P1-52
z/D'
T
JywT
24.6
reporting values of x /T, Report the value of Nwfgr A~h, file in writing and at head of
16.4ile.
0 < z/D'
x'/D'
For each of files P1-50 through P1-52, create a binary array of N elements with labels z/D',
< 1
24.6
293
:
S. ..
.o ' -."
.- >*
.
"
-..
. ..
.
.
_ -. --
,
.
*
Independent
Dependent
F1ile #
Variable(s) (Label)
Veriable(s) (Output)
Pl-53
y/D'
w
•
-.
-
-- . - - ..
.
.
., -
.
Variable(s);p. Locations
/rw,
0 < y/D'
Comments
< I
For each of files Pl-53 through PI-55, create a binary array of N elements with labels y/D', IT/*.Z. reporting values of T Report the value of N for e~ch in writing and at head of
.2_
Pl-54
y/D'
T
0
Pl-55
y/D'
T,
0 < y/1n < I x'/D' - 24.6
W/,Z64Zefile< 1 x'-D' - 16.4
Special Instructions
.- .
Range of Independent
____/D'______ _
1.
-
for predictive
case
"
iastructions:
files
format
are
given
at
x/D
in
the Appendix
to
the
Overview of PLedic.Ave Test Cases. 2.
Files
P1-I
stream of
through
PI-15
constitute
the cruciform.
nel flow of Case 0111. to evaluate
if
input
data
You should compute The data in
(P1-i
through
employed works well
in
the larger chennel befcre the more complex asymmetric
case is
3.
X9,tachs
i.
domain
4.
Note two
coordinates
files
PI-10
through
used
(see
Pi-14 are
to
Fig.
x',y'
I).
70,
two
diameters
up-
these daLa by computing square chan-
these files
the particular method
-
cover
etc.
P1-15)
the
will be used
symmetric
flow in
carried out. 0 < y/a < 1;
0 < z/a
refer to section with
inset
cruciform. Nomenclature el
half-width of square duct
a'
diagonal width 3f modified flow passage
p
static
(Fig.
pressure coefficient:
Cp
D
width of square duct
Dt K
width of modified flow passage turbulence kinetic energy
Po
static pressure at
p
static
Reb
bulk Reynolds number:
u,v,w
fluctuating velocity components
(Fig.
x'/D'
2)
(Po
(Fig.
3)
-
I) (Fig.
i)
0
pressure Reb = UbD/V in
the x--,
y-, and z-direction,
respectively u 2 ,v
2
,w2
Reynolds-notrmal-stress
iomponentn
-uv,-uv,-uv
Reynolds-shedr-stress
U,VW
mean-velocity components in
Ub
bulk velocity in
componentF the x-, y-,
sqjurre duct (0 294
and z-directions,
< x/D < 72)
respectively
.-
Ubm
bulk velocity in
Uc
axial centerline velocity in squace ducL
Umax
maximum axial velocity in moditied flow paseage
V'
transverse velocity component in Lhe y'-direction
x,y,z
Cartesian coordinates (Fig.
x'
axial distance measured from leading edge of cruciform (Fig.
y'Idiagonal
modified flow passage
distance increments (Fig.
a
wedge half-angle (Fig.
*
absolute viscosity
v
kinematic viscosity
p
fluid density
Tw~y
< 25)
2) 1)
3)
2)
1)
local wall shear stress on the --all y T
0 (Fig.
3):
W(DU/3Y)yO..
-*
integrated average value of xwry along the wall y - 0 local wall shear stress on the wall z
Sw,z[
*wzl
< x'/D'
coordinate measured from corner (Fig.
Ay,Az
y
(0
-
zI (Fig.
3):
integrated average value of TWZl along the wall z
z.
..
.
..
..
.
..
-
.
~
..
.
.
. .:
..
..
...
. .
~ ~
~
295
. ...
-
"
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.-
. . -.-
- .
'- .
y£
:•'-:i-®
PRIMARY FLOW DIRECTION
152
46
49*
41
28/ ./
.
.
f
::,/2 y/u
. 1I(l yp)
Figure 2. Data point locations (,) in an octant of the square duct. Numbers refer to locations in files P1-I through PI-15. Numbers sequential left to right on each row. O.O250
_____
"CRUCIFORM
____
_
1/
___
WALL
DUCT WALL 0
I
CRUCIFORM WALL (zs z )
01,
CORNER BISECTOR
ylyDUCT
WALL-
(y *0)
000.25a
Figure
3.
Reference dimensions and coordinates cruciform and square duct.
for
modified flow
passage
formed
by
296
%
.'-
9 6
.
.*
-
-
-
-
-.
-"
" "..•
BACKWARD-FACING
STEP:
VARIABLE OPPOSITE-WALL ANGLE
PREDICTIVE TEST P2 Flow 0420
Case 0422 Description by Jchn K.
Eaton
SUMMARY =•
GNERAL DESCRIPTION are being made in site
the
step
(channel
*
is
set
spa:,.'etep
dimensionality.
is
will be provided will
this
in
should
Fig. be
adequate
and Reynolds
0,
the
a
6,
and 10 degrees.
shear-stress
in
range
as
function
of
profilLB,
The
1.
to
x/h
20
is
shown in
SMeasurements oppo-
step aspect-
to provide
ratio
good t,,:o-
this apparatus. -2
a.
The wall
< a < 10 degrees.
The
Wall-static-presoure
data
A detniled data set, will be
supplied for
includa-
6.
the separated region and
-
DETA-LED FLOW GEOMETRY test secti'.n geometry
fied at a 44 are in "
shown
of U and u', will be provided along the centerline in
The -
as
for angles in
be measured
downqtream of teattachment
*
angles
twn.lve;
foi angles of -2,
2ean velocity
Profiles
hclsht)
length
will be provided ing
"arious
sudden expansion.
The spanwise uniformity has been checked
Measurements reattazha.ent
at
a single-sided
,•/s
Tacle
saadpaper
1.
The initial
station four step heights upstream of the step.
at
fully
Fig.
this
point.
turbulent. I-
The boundary layera Various
The step-wdll
roughness.
The
parameters
boundary
entire wind
conditions
The free-stream velocity is
on both the step-side
describing the boundary
layer
is
tunnel
thicker is
because
sketched
in
it
Fig.
and opposite walls layers is
TABLE 1 F-oundary-Layer Parameters Measured at x/H -
L
Opposite Wall
1.69 cm
1.41 cm
0.257 cm
0.240 cm
0
0.190 cm
0.172 cm
H
1.351
1.398
Cf
0.0030
0.0028
Re0
5500
5000
297
L•L__t
-4
Step-Side Wall
-.
are
tripped
compiled with
2 which illustrates
the exit conditions-
699
are apeci-
thv
H- .1cW= 10.16 c a
-2to egrei =
10
H- 144 m/s
Figure 1.
Sketch of wind-tunnlfl~
test section (not. to scale).
choked nozzle (flow rnetering)71
contraction exit
1.0
mn
.
~. W..4~-. n
2.0
mn exit to low pressure chambcr
Figure 2.
Sketch of wind tunnel (not to scale).
298
,
DISCUSSION Flow 0420 (P2) For this flow there was general agreement that a should be slightly negative for at least one test of this cape. in
Stha,
It was expected that experimenters will generally measure all quantities they can the time available. F. Cessn-r, J. Eaton, D. J. Cockrell, and U. Tropea agreed the mean normal velocity
reattachment.
E.
Reshotko
.
,ta would be desirtble,
suggested
at least for stations ahead of
that as much data
should be obtained
for
this
case as for Ca.e 0421.
7
9 .i
I
:~ ::.!l!•i!!ii~: "--:i.i.::••."!•:•:-: . i ::: ." -:: "! "! " ~i
([Ed.:
This is planned.] 299
~
~
A
"ENTRY
CASE/PREDICTIVE TEST
SPECIFICATIONS FOR COMPUTATION
"Case +'
00422;
Coordinator:
J.
K. Eaton
Independent Dependent Range of Independent Variable(s) Variable(s) Variable~a); (Label) (Output) Locations
File
f
Comment'u is for step-side wall. Pwall F e instruction 2. c -2.
P2-1
x/H
C Pwa 11
-4
< x/H < 16
P2-2
x/H
C Pwall
-4 < x/H < 16
a= 0
r-2-3
x/H
C Pwall
-4
< x/H < 16
a
P2-4
x/H
Cpwal
-4
< x/H < 16
a
P2-5
a
xR
-2 < a < 10"
-6
10'
xR ! point where
Tw -O0
In
computations. P2-6
y/H
U/U0
full channel
x/H - 4.
P2-7
y/H
U/Uo
full channel
x/H - 16.
P2-8
y/H
U/Uo
full channel
At computed xR.
P2-9
y/H
uv/U 0
fxll channel
x/H
P2-10
y/H
uv/U2
full channe
x/H-
P2-11
y/H
full channel
At computed xR.
-uv/U2
4.
-
16.
Special Inst ructions: 1.
'Instruction& for
predictiv-a
case
.'lea format
are
given
in the Appendix to the
Overviev ofkPredictive Test Caees. 2.
For eac.i file indicated in this case,
create a binary array of N elements.
Report
value of N for each file in writing and at head of file. 3.
Compute results along centerline; station:
14.C)
'--
x/H
--
two-dimensionality can be assumed.
4.
300
.'
...............
S
m.
.
.
m
.
.
.
• •-• •... • • - ,-•4 : .• .•-• .•.•: _ ,.•..-
.
.
.
.
.. =• .:
S., ..
.
.
"_ '-
,m
.. " ".
--
"
--
-
i
. ".
%
~~...
- .. m"
. "-
,
. .
.
. W,"•a..m,".
, "
m
,
".
. " . "
a.
.
m
m
"..
.
.
..
. - . -
.
l
-
.
.
.
.
. - ...
'
"
"
.
"
l
i
BACKWARD-FACING STEP,
TURNED FLOW PASSAGE
PREDICTIVE TEST P3 Flow 0420 Case 0423 Description by John K.
Eaton
SUMMARY
GEIERAL DESCRIPTION Measuremr.nts stream
of
the
are being made
expansion
shown in
apstream duct as smoothed height)
has
Fig.
twelve;
this
two-dimensionality
will
walls,
1,'t
sudden can be
expansion. set
at
The
duct
an angle,
downto
n,
the
I
The corner on the wall opposite the step has been
see Fig.
should be be
a qingle-sided
1.
to prevent separation; is
in
parallel
Tlic step aspect ratio (channel span/step
1.
adequate
checked
by
to provide
momentum
and
good
mass
two-dimennionality.
balance
calculations
The and
by
spanwise uniformity checks. Measurements reatraci,ment
uration.
in
the range
The
len3th will be measured as a function of a and wall-static-preosure
data
for angles of 0, 5, 10, and 1.5*.
turbulence-intensity
Profiles will
tachment to
for angles
0 < a < 15 d'grees.
will be provided velocity and
will be provided
profiles
be provided
in
A detailed data set including mean-
will be supplied
the separated
for the 10-degree
region and dowrstream
configol
roat-
x/L - 20
DETAILED FLOW GEOMETRY The test
section geometry is
)0
fied at station
where
shown in
x/H a -3.
The boundary layers on both walls of
lated
in
used.
The
test
i).
The step-wall section extends
1.
At station
m/s.
Table
Fig.
( ),
a distance
Boundary-Layer
conditions are speci-
the free-stream velocity is
the channel are turbulent (paramr:ters
boundary layer is
1.6 m the flow exits into a large
The initial
thicker because
of 1.6 m downstream
of
e thicker
12
tabu-
trip
the expansion.
was At
room. TABLE 1 Parameters Measured at
x/H - -3
Step-Side Wall
Opposite Wall
1.78 cm
1.26 cm
S0.246
cm
0.183 cm
0
0.180 cm
0.135 cm
H
1.363
1.358
Cf
0.0042
0.0045
Re 8
1460
1070
301
*..' ... :
:..:::.
.
..
::• .:,..:. : . . ,-.:: .. . .,:
.::
. :: .-
.: : :.::: . : : .- . .
:.
10.2 c
h
-51c 011
a-
U
0 to 15 degrees - 12 m/s
Figure 1. Wind-t. 4xaie' configuration.I
302
ENTRY CASE/PREDICTIVE TEST SPECIFICATIONS FOR COMPUTATION Case 10423; Coordinator:
File
I
Independent Dependent Variable(s) Variable(s) (output) (Label)
J. K. Eaton
Range of Independent Variable(s); Locations
Comments See instructions 1, 2, 3, 4, 5.
UP3-1 P3-2
x/H
CP-
x/H
C
/
0
0a
-3 <x/H <20a
.
for step-aide wall
-w'
P3-3
x/H
C pw's
-3(<x/H <20
a
10*.
P3-4
x/H
C Pw's-
-3 < x/H < 20
a
5*
See instructions 1, 2, 3, 4, 5. X/H
P3-5
-3 < x/H < 20
C
a-O0'
Pw'0 P3-7
x/H
C
P3-8
x/H
CP0-3
I3.
fo
u7x R
for wall opposite step
-3<xIH < 20
a
< x/IA < 20
a
10*.
150.
0 <
pitwhr
W "Q1*R 0in
Special Instructions: I.
format are given in the Appendix to the
Instructions frpredictive case files Overview of Predictive Test Cases.
2.
For
each
file in
this
case,
create~ a binary array of N elements;
number of elements in each file in writing and at head of file. 3.
Take
xR
4.
U 0 . 12 rn/a; 5al c
Pw's
/2
-
of reattachment (T
-location
() u
1/2al 2
-
station
-
0) computed by your program.
x/H - -4.11
on step-side wall.
on wall opposite step.
303
........................................
..
.
.
.
.
.
.....
report
the
BACKWARd-FACING STEP: VARIABLE AREA RATIO PREDIrTIVE TEST P4 Flow 0420 Case 0424
"--
Descriptton by S. J.
Kline
SUMMARY
GENERAL DESCRIPTION This
(a - 0).
case haa
the
geometry and
saue
oomenclature
as Cases
0421,
0422,
and 0423
This case consists of running with various area ratios using a sufficient
number of values Ro thaL resultr, can be extrapolated to the limiting values (0,
1.Nfor
the inverse area ratio (A 1 /A 2 ). The
initial
data
effects of variation
in
are
those
initial.
'or
R6,
Case
0422.
If
we will be happy
you
desire
to receive
to
investigate
the
output on that effect
also. We suggest
or 0423,
computors do not do this case unless
so that oaly a few
additional
production
output requested.
304
they have set u? Case 0421,
runs are
required
0422,
to obtain
the
ENTRY CASE/PREDICTIVE TEST SPECIFICATIONS FOR COMPUTATION Case #0424 (P4);
File
Coordinator:
Independent Variable(s) (Label)
Dependent Variable(s) (Output)
Range of Independent Variable(s); Locations
A 1 /h, 2
xR/H
0 < Al1A 2 <1
P4-1
J.
K.
Eaton
Comments 1.
H
step height
-
A,
upstream area
-
A2 - downstream area See Fig. 2.
1, Case 0421,
Compute
p.
103.
for enough values
of AY/A 2 to establish limiting -slues of XR/H at A /A
A1 /A
and
0
-
2
1
-
2
by extrapolation of XR/H. 3.
xg/i
value of
-
x/H where
computed value of
rw -
0.
to
the
Special Instructions: 1.
Instructions
for
predictive
case
files
format
are given
in
the
Appendix
Overview of Predictive Test Cases. 2.
Create
a binary
array
for
file
P4-1
of
V elements.
Report
the
value
of N in
writing and at head of file. 3.
comment:
Special 0423
(a
-
relatively 0421,
0422,
0*)
Since
with
easy or
specifications
some
the
geometry and flow are
possible
variations
to run the computations 0423.
Please
for Case 0422,
use
the
in
for file initial
the same as Cases
inlet
conditions,
P4-I,
0421, it
should
you do any of
if
conditions
of
Case
0422
instruction 5).
-. ...
S..
x.-.
.o
305
.
.
.- .
- .
... , -.
*
.
.-.
'..,
0422,
-'
be
Cases (see
7-.-
7 . 7=
FLOW IN A PLANAR DIFFUSER WITH TAILPIPE PREDICTIVE CASE
y
Presentation Prepared by John K.
Eaton
GENERAL DESCRIPTION
in
flow will reattach included
angle
(20)
for
the
shown in
The flow geometry is
the tailpipe. diffuser
will
(tailpipe) and the
on one of the diverging walls,
The diffuser will stall
will be investigated.
duct
planar diffuser with a downstream
The flow through a wide-angle,
be
50*.
boundary
The
I.
Fig. layers
The total on
all
four
walls of the inlet duct are turbulent. Measurements < 75.
In
addition,
mean velocity,
profiles will be measured
turbulence
and
intensity,
-5
< x/W. (-u'v')
Reynolds stress
and downstream of
upstream of separation
and turbulence
mean velocity
pressure will be supplied for the range
the wall static
of
The
reattachment.
data will be obtained using hot-wire anemometry and pitot
probes. .
DETAILED FLOW SPECIFICATIONS The
dimensions of the experimental and turbulence
of mean velocity that
requested for
this
the
intensity
The
location.
- O) are shown in
1.6 cm thick at
proximately the
sponwise 2%
about effect
than
this
on
the
the
x/Wl
-
edge
velo
edge
-5.
The core for
velocit
uniformity
x/W1
-
stress
shear
intensity
-5.
We
of
profile
(-u'v')
profiles measured
end-wall boundary
velocity
the
.he
if
the
have
on
Fige. 2 and 3.
show that the
profiles
the
direction;
higher
of
The
a Reynolds
Inlet profiles
1.
to check the two-dimensionality of the inlet
Spanwise profiles were measured but are not shown here.
Fig.
measured at
and turbulence
mean velocity
the channel centerline (z
have been
also provide
experimenter
shown in
are
facility
upper
lower
downstream
is
are ap-
layers
somewhat non-uniform in
end-wall
end-wall flow
flow
will
boundary
boundary be
is
layer
layer.
invectigated
The at
a
later date. SPECIFICATION FOR COMPUTATIONS Computations
should begin
computation should continue to
at
or upstream of
x/WI
-
75.
the
first
station
x/W1
-5.
The
Three types of output are required:
lThis case was not finally accepted as a predictive case for the 1981 Conference. in the data, including three-dimensional This arose because of certain irregularities effects which could not be corrected before January 1981, the deadline for summitting predictive case specifications to computors. 306
L-4
(1) plots of global variables,
(2)
plots of mean-flow velocity profiles,
and (3)
plots
of turbulence intensity aud turbulent shear stress. The global variables should be plotted against x/WI (abscissa) 75
at a scale of
(a)
Skin
friction
velocity at
(b)
(c)
I cm - 5.
for
-5
< x/Wl <
The global variables are specified below.
plotted
as
1 PI 2 l/
cf
where
,
U
is
free-stream
x/W1 = -5.
Abscissa:
x/Wl; range,
Ordinate:
cf; range,
The
static
Cp
(p-pl)/1/ 2 pu 2 l
-5
< x/Wl < 75; scale,
0 to 2 x 10 3 ; scale,
pressure
on
the
diverging
1 cm = 5.
1 cm - 2 x 10-4 and
parallel
(p1 is the static pressure at
x/Wl (same range and scales as described above).
Ordinate:
cp; range, -0.1
1 cm
plotted
0.1.
-
The momentum and displacement thicknesses should be plotted on the same figure. Abscissa:
x/Wl (same range and scales as described above).
Ordinate:
0,
0 ; scale,
1 cm
-
1 cm.
uorrar Detail (Inlet and Exit)
20
-
50*
inlet station at
3 cm
WW W2
-
31 cm
N
-
30 cm
M
-
180 cm
h
as
x/W1 - -5).
Abscissa:
to 1.0; scale,
walls
Uc(x/Wl v
-
-
-5)
Figure 1.
- 44.5 m/s
1.63 x IO
16 cm Test facility configuration. 307
.... ......
x/14
m2 !¼ /
-5
0
o0
Y/w
00 0
0.9
" 0 0 0
0.8
0 0 0.7
g
0
-
0.6
0.5
0.4
0 0
0.3
0 0 0
0.2
O 0
o 0
0.1 0
00
p~00
0.5
0
1.0 Uu/ C
26 - 500,
Figure 2.
N/W1 -
10,
AR -
tO.3,
Uc
= 44.5 m/s
Inlet cross-Rtream direction velocity profile. 308
S~~~~~~~..........."""-..•".... '..............'.....-.-.. "~~~~~~~~~~~~~~~~~~~~..:..-:---. "---.....-.'." .-..., .....
S.
.-. ••- .
.,_
-.
•-_-. ....
_•..
• ',._,•.
.•.••
-•
,-",ii
,........""
,
••i
.
. ..-*.
.
....
..-..
,•
.
..
1.0 Y/V) 0
0.9
•
0 0
0.8 0 -0.8
"7
0 0
0.6
0 0
0.5 0,
30.4
0
L°
0
0.3
0.3%
>
0
0.2 0 0 0.1
0 0 0 0, 0
1
26
Figure 3.
-
50,
2
10,
N/W1
3
AR = 10.3 (at
4
3
x/W1 =-5)
Inlet cross-stream direction turbulence profile. 309
......
...
....
....
..
. .
.......
.
""77
ow
SHOCK-BOUNDARY LAYER INTERACTION Preliminary Specification
Predictive Case
--
6
.
Presentation Prepared by John K. Eaton GENERAL DESCRIPTION
In this experiment,
a shock-boundary layer interaction will be studied at various
free-stream Mach numbers. and
the
impinging
Both the flat
A turbulent boundary
shock
will
originate
at
a
layer will be grown on a flat plate
separate
shock
generator
plate and the shock generator will span a lxl-ft
Measurements will
include wall static
pressure,
(see Fig.
supersonic wind
mean velocity profiles,
1).
tunnel.
and skin-
friction
measuremonts.
There is
a possibility of obtaining data at higher Reynolds numbers by modifying the
test plate.
Data
will
be
obtained
for
the
conditions
shown
in
Table
1.
.
This will depend on the extent of the region of two-dimensional flow.
DETAILED FLOW SPECIFICATIONS A detailed
flow specification
cannot be
given
at
this
time.
Preliminary
work
will be done with a l.minar boundary layer to check the flow two-dimensionality. the preliminary work indicates that the flow conditions are well controlled,
If
the ini-
tial condition data for the turbulent boundary layer case will be sent to computors.
TABLE I
'
Test Conditions
*This
M
Max Re (based on plate lelgth)
1.6
2.1 x 106
2.0
2.2
2,5
2.3
3.0
1.8
3.5
1.5
4.0
1.?
case was not finally accepted as a predictive case for the 1981 Conference.
elimination of adverse three-dimensional time available before January 1981.
effects
proved
too difficult
to solve
in
.
-
310
.
.
.
-
.
,""
'
The the
.0
A44
/
/.
1
I
I
I
I
/
I
SHOCK GENERATOR (VARIABLE. INCIDENCE)
_
-b
TEST PLATE 12 in.
10 in.
I
.............. . . .
Figure 1.
I
I
-I
Wind Tunnel Configuration
DISCUSSION Predictive Case ' E.
P.
S"tton suggested
of obtaining
two-dimensional
ten.hnica' flow.
oversight is J.
Fatoa
remarked
agreed to provide technical oversight for this case.
311
Im;
necessary to ensure the best chance that
S.
Bogdonoff
had already
TRANSONIC AIRFOIL Preliminary Specification -
Predictive Case c
Presentation Prepared by John K. Eaton GENERAL DESCRIPTION Data
are being
plete data '
obtained
and
a
ii)
separation. The
a NACA 64A010
airfoil
with a
acts will be obtained foe" three angles of attack
Mach number of 0.8. case,
for
Two additional higher
Mach
The experiments
top and bottom walls
of
.,ases will be
number,
the wind
(0,
tinnel
are
2,
investigated:
low-angle-of-attack
are being conducted
15.24-cu
in
case,
perforated.
Com-
and 4 degrees) i)
a 6"x 22"
chord.
at a
a low Mach number which
gives
severe
transonic wind tunnel. Boundary-condition data
including U and V on the upper and lower wind tunnel walls will be supplied. Measurements component,
frequency-shifted, of U,
measurements model,
will include mean and
V,
u'2,
rms pressure
laser-doppler
v12,
along the model surface,
and u'v' and in
on
velocimeter
the airfoil
A two-
system will be used to obtain
Measurements will
.
surface.
be made upstream of the
the near and far wakes.
DETAILED FLOW SPECIFICATIONS Detailed the
flow specifications
boundary-condition
data.
will
be issued after
These data
should
be
the experimenter
sent to
computors
has measured
by January
31,
1981.
DISCUSSION
Predictive Case L There was general agreement with E. top
and bottom
troublesome technical
"K:.:
in
tuLnnel
walls
are
thi3 experiment.
reviewers
P.
perforated,
Sutton's observation that, the
M. Childs and J.
side-wall
boundary
Spreiter were
since only the layers
could
be
suggested as possible
for this experiment.
This case was not finally -.ccepted as a predictive case for the 1981 Conference. There were reservationo regarding the small aspect ratio of the airfoil and the inherent difficulties in avoiding three-dimensional effects. There was also insufficient time to properly document the data in time for the specifications to be submitzed to computors by January 1981. "This e:-periment is currently being completed.
"312
,._
.
.
.
-
DISCUSSION General Predictive Cases 1.
recomended
It was
that all
the
predictive
teat cases
proposed
should
be
re-
tained. 2.
The need
for specifying
initial, boundary and downsr:eam conditions were exten-
sively discussed for all predictive cases. 3.
E. Reshotko, metric
J.
Eaton, C. Sovran,
information,
and J.P. Johnston favored giving complete geo-
together with mean an'!
turbulence quantities
at an initial
plane, to computors. 4.
1. Durst favored providin& downstream conditions for those -ith elliptic coden.
5.
J.
Hunt
suggested
that
some spectral
data and/or
information concerning
scales
would be needed by some methods. There was broad agreement that better specification of test geometries, exhaust conditions,
vould be needed.
The
including
issue of whether flow specifications favor
pcrticular calculation schemes vas raised and discussed,
but not resolved.*
[Ed.: In the step case, specifications will 8ive geometry and initial conditions. Computore requiring downstream boundary date can generate them by employing a fictitious tailpipe of sufficient length for their purpose.]
313
FLOWS WITH BUOYANCY FORC9S
Flow 9000 gvaluator:
J.
C.
Wyngaard*
SUMMARY (From Letter from J. C.
In
Wyngaard
to S.
January
1980 you asked me to evaluate in
1980-81
AFOSR-IITTM Stanford
for the
to undertake
the task,
and in
April
J.
Kline,
7/15/1980)
more detail buoyancy-influenced
Conference
on Complex Turbulent
I expected
to ha',e an evaluation
Flows.
I
flows agree,
done by sometime
iti June. i .
agree
that an important part of turbulence modeling is
flows
with strong
elude
both unstably
forces.
I
also agree
and stably stratified
flows
However, my reflection and research
rcaments. me
buoyancy
that an evaluation
of
there
flows,
to
that
the ability
such an evaluation
should
from laboratory and geophysical orer the past
the
to calculate
standards
In-
envi-
few months has convinced
you have
established,
is
not
possible at this tiMe. The boundary most
layers
accessible sources
-
in
states
*
stable
ranging
quasi-steady
dimensional Reynolds it
can be
physical
and
They
and
onea
so
atmosphere
and
the
having
their
large and
upper ocean
structure
states
effects.
of
are
is
often in
shear
well-suited
Thus a successful
to are
to
one-
the laboratory often have
nearly
stratification
flow
turbulence,
Reynolds-number-dependent;
flows as
the
They are found
neutral
Reynolds-number
flows
are perhaiý;;
turbulence.
through
thus
stratified
laboratory
arbitrary
cont&inment
convection
extremely
By contrast, that
low
free
homogeneous,
csifficult to find
and
negligible
lower
have
locally
idealizations.
numbers
the
from essentially
stratification.
often
tion,
int
of buoyancy-influenced geophysical
in
addi-
one-dimensional as
geo-
(flux Richardson number)
evaluation would have
to be
based largely on geophysical data. Over .
have
.
of
the
past
5-10
years,
a
large
number--certainly
sevpral
appeareL which deal with the modeling of these geophysical these
flows, tion
models
are
variants
and often they are effects,
layers.
to
Many of
nble,
reproduce these
of
second-order
with some
what
papers
the
cdo
is
type
dozens--of
boundary layers.
developed
for
use
known
include
Center for Atmospheric Research,
in
Most shear
tuning for convective or stable stratificaof some
the
broad
attempts
features at
of
these
P.O.
"314
Box 3000,
boundary
comparisons with measure-
ments.
.National
papers
Boulder,
CO
80307.
I'."
The first is
There are several points I would like to make about this activity.
our knowledge of the structure of these geophysical boundary
broadly speaking,
that,
does not approach
layers
of laboratory
that
While I believe that
shear flows.
the
first measurements of the Reynolds shear stress and heat flux budget were done in the this is
not in the laboratory,
atmosphere,
have the exhaustive sets of carefully ti.ken, of
ments
mean
the
and
structure
turbulent
we simply do not yet
kather,
not typical.
statistically reliable, of geophysical
complete measurethat are
boundary layers
needed for flow documentation. A second point is
"physical aspects
of
that of laboratory shear flows,
lags so far behind
flows
and
verification
that because our documentation of the structure of
is
refinement
this in
a manuscript
being
fairly
which will appear in
that model
I fear I pointed
neglected.
widely
these geo-
Turbulent
Shear
Flows
out some II,
the
In particular, I argued that in convecproceedings of the 1979 London conference. tively driven turbulence the pressure covariances, transport terms, and the diessipation rates in the second-momenL equations behave quite differently than in shear flow, In order
and that the widely used shear-flow closures for these terms are incorrect. to
show this,
however,
I had to average
over many sets of measurements
and the conclusions are more qualitative tha:i quantitative.
ments,
tion, perhaps it
and experi-
Given this situa-
is natural that buoyant-flow model( rs do not seem to work as hard on
model verification as shear-flow modelers do. Thus I feel that the buoyant-flow evaluatior. could uit now be done to shear-flow While many of
standards.
us in
the field believe
that contemporary models
do make
significant errors in their predictions of convective turbulence structure, it is all I think that an attempt to but impevsible tn dorumenr thq 94eq'.otelvy at this time. do such an evaluation,
in the context of your conference,
migh'
ultimately turn out to
be a disservice to the community. Perhaps what we need instead for buoyancy-influenced flows is Townsend
has
done for
shear
flows.
Important
topics might
a monograph such as
include,
for convective
such active research areas as
flows, I.
structure of the overlying entrainment region
2.
deviations from Monin-Obukhov Rimilarity in the surface layer
3.
the nature of the pressure transport of turbulent kinetic energy, known to be important at the bottom and top
4.
the behavior of the turbulent transport (third-moment divergence) terms
5.
the effects of baroclinity (i.e., vertical variation in the horizontal mean pressure gradient) on boundary-layer structure
6.
effects of entrainment on boundary-layer structure
7.
the vertical profiles of dissipation rates of turbulent kinetic energy and scalar variance
315
I
8.
validity of local closures in convection
9.
influence of structure.
the shape of the buoyancy-flu,
profile oa boundary-layer
These point could be discussed in the contLxt of the underlying physics, do exist could be included,
with the appropriate caveats.
concerns a key structural aspect, be included in a data archive.
I emphasize that none is
and what data
While each of these points now well-enough measured to
One could make a comparable list,
and statement,
for
stably stratified flows. I hope that my position does not cause you serious problems with your conference. After these months of reflection,
however,
it
is
the only one I feel comfortable with,
I would be happy to dle-u:s arey of the points with you in more detail.
DISCUSSION Flow 9000 B. Launder:
I
viewpoint
am in general Lgreement with John Wyngaard's stakewent but I feel his seems to be unduly pessimistic.
precision of
The data may not jchieve the degree of
the laboratory non-buoyant data, but they are cerzainly good enough
to do at least some coarse sorting out among turbulence moels now in use. might also remark that "answers" quite the precision required
for buoyant flows are generally not needed with
in aerodynamics
(a
factor of 2 on effective diffu-
sivity is
often close
(when
question of commissioning a buoyant-flow
the
enough).
One
I
would
also underline
my earlier
observation
survey was raised)
that be-
cause buoyant flows involve coupling between turbulent heat and momentum fluxes, it
would
seem more
informative
to
precede
such a
survey
with one relating
V
to
heat-transport mechanics with negligible buoyancy effects. , -
Recommendation: Buoyancy effects would requir• a more detailed study, including also the matter of scalar transp rt. It is unlikely that this can be done in time to
-.
be meaningful for
*]
not be used for the 1981 Conference.
the 1981 Conference.
It
was confirmed
that this flow should
316.
".•',
~316
•
"
• •-
.
-
.
...
..
...
.
.
.
.
•
I.•
.
-
FLOWS WITH SWIRL Flow No. Evaluator:
0340
A. P. Morsee
SUMMARY (presented at the 1980 Conference by A. P. Morse)t
INTRODUCTION This summary deals only with free swirling flows (flows in which the main region of interest is remote from solid walls). A full report has been submitted to the Stanford 1980-81 Organizing Committee, Morse (1980b). The addition of swirl has large-scale effects on free jet development. In particular, the rate of mixing increases with swirl intensity.
Thus swirling
Jets spread more quickly,
velocities decay more rapidly than in a non-swirling
jet.
and the mean
In a strongly swirling jet
the gradients of static pressure set up across the flow field introduce adverse axial pressure
gradients
in
the region of swirl decay,
and these may be
cause reversal of the forward velocities near the jet axis. is
set up downstream of the jet orifice.
of the stream lines,
and the flow is
strong enough to
Thus a recirculation zone
Weaker swirl leads to less strong curvature
.:
then amenable to analysis as a thin shear layer.
Even so,
the spreading rate may reach as much as twice that of a non-swirling jet. The enhanced mixing resulting from the adverse pressure gradient leads to increases in the turbulence
intensities.
Further downstream,
where the swirl field is
•. .
weakened,
"
the turbulence levels and the spreading rate reduce approximately to those of the non-
-.,
swirling jet. EXPERIMENTAL INVESTIGATIONS"'.' A summary of previous investigations of free swirling flows
is
given in Table 1
of which five are considered to display satisfactory internal consistency. These are presented in Table 2, alongside the earlier measurements of Rose (1962) and Pratte and Keffer (1972). tions.
Dept.
of Mech.
All five cases
are suitable
-
'
Engr.,
Imperial College, London SW7 2BY,
England.
317
... %
-
test cases for comparison with computa-
The report on this flow was received too late to evaluate it and review it in accordance with the standard procedure. It is accordingly not a test case for the 1981 Conference.
~~~~~~....-.'.'.".' .-.'.'." .'
"
. ."
.• * .. '- , .
•.. .
..
"
.-.-
'
.'-"..-
•."
The swirl number,
S,
in Tables 1 and 2 is
defined ar
RG
x
where R is
a characteristic
dimension of the flow (usually
the axial momentum flux, and Ge is The data of H6sel (1978) the
stagnant
"(1980a)
atmosphere.
the nozzle radius),
G. is
the angular momentum flux.
and Fornoff (1978)
The exit
diameter
of
refer to a 3ingle jet exhausting into the
jet
nozzle was
also studied the single jet (exit diameter 25.4 mm)
20 mm.
Morse
and extended the investi-
gation to the case of a jet exhausting into a uniform stream of low turbulence intenThe initial velocity ratio of the two streams
sity.
velocity of
the outer
(inner-to-outer) was 2.70.
jet remained constant (to within ± 2%)
The
over the axial range of
measurement. Co-axial (1980).
In
jet flows were also studied by Hellat
the latter case,
diameter ratio of 2.79,
(1979)
and Ribeiro and Whitelaw
the flow originated from concentric pipes of an internal
the two jet streams being separated initially by a wall thick-
ness of 0.34 times the (internal) radius of the inner pipe. The ratio of the maximum jet
velocities
occur.
(inner-to-outer)
Hellat's
ratio of 2.07. tion and .
flows
were
at
the
generated
exit plane was 0.71. in
concentric
unfortunately,
for the highest
an internal
diameter
one without recircula-
swirl number,
by the measurements was insufficient to cover
Icovered
did not
pipes of
The investigation covered three swirling flows,
two with;
Recirculation
the axial distance
the uhole of the area in which
flow reversal occurred.
"All of
•,l
the cases recommended as suitable for prediction entailed measurements of
the three components of the mean velocity vector and all six non-zero Reynolds stresses. .. ,The
H6"sel and Formoff used laser-Doppler anemometry,
anentometry. experental below.
flow conditions
the remaining authors hot-wire
at the nozzle exit are givzn in
The accuracy of the measured data is
the references
typical of that iv jc- or mixing-region
flows (see Flow 0310). TEST CASES Case 0341.
Ribeiro, M. M. and J.
H. Whitelaw, J. H. (l)'O)
*Co-Axial Jets With and
jWithout Swirl" I'nthis
"S"
0
and
stationary.
-- :-eri-ent S - 0.31 This
test
-. 1-.- mf U, V, W and all u iu
for downstream distances up to case involves
decay of the maximum swirl velocity.
"318 ' I..
x/D - 6.
the theoretical
tween the variation of the centerline values of U, u I
were measured for swirl numbers The external field was
and experimental 2
and v
2
with x/D,
coepacison beas well as the
"Axisymmetric Free-Shear Flows With and Without
(1980a).
A. P.
Morse,
Cnse 0342.
Swirl"
are given
for
the
velocity ratio is
jet
0.32
-
results
into a uniform flow in which the inner to the outer
issuing
2.70. "Drallstrahlenuntersuchungen mit elnem Weiter-
l1sel, W. (1978).
Case 0343.
S
similar to Case 0341 with the addition that for
This case is
entwickelten Laser-Doppler-Messverfahren" similar to Case 0341 in
This case is
the swirl numbers tested are Case 0344.
J.
Hellat,
S -
1.33
which the
and
field is
external
but
1.70. Erdgas--Diffusion
"Turbulente Str~mung und Mischung in
(1979).
stationary,
Flammen mit Luftdrall"
S
-
This
case
is
similar
0.40,
1.15,
and 2.28.
Fornoff,
Case 0345.
Case
to
0341
but
has
an
extended
of
range
S
covering
"Experimentalle und Thcoretische Untersuchung von
M. (1978).
Drallstrahlen" similar to Case 0341 but has an extended range of x/D up to 40,
This case is S
-
for
This range of x/D was covered in Case 0343 for larger values of S.
0.53.
CONCLUSIONS are
data
Reliable
for
scarce
the measurements of H6sel (1978)
and Pellat (1979)
Neither set of data is
able at present.
H6sel's data display
for prediction.
particularly
flows,
jet
free-swirling
at high values of the swirl number).
flows with recirculation (i.e.,
field
of
the
data
are
of
points
Moreover,
flow.
Reynolds-stress
of interest
measurement
components
is
the
as a suitable test case
however recommended
too large a variation in the axial and angular
for good definition,
first
full
only available
particularly of
description
at
x/D
-
the profiles do not
2.0,
the
so
in
0.6 < x/D < 2.8.
internal
In Rellat's
consistency,
but
only
extend
over
flow with the highest swirl number
the near-
mean-velocity
that the
the S
-
and
prime region
(the recirculation zone) cannot be covered in the computations. greater
for
probably represent the best avail-
momentum fluxes (see Table 2) and, although symmetry is excellent, contain sufficient
those
In this context,
Hellat's
axial
2.28;
range
this x/D
range does not cover the region of recirculation. The data of Ribeiro and Whitelaw (1980)
and Morse
suitable cases for comparison with computation. formier data cover one flow (in of the latter flows, variation
in
(1980a)
These are summarized in Table 2.
a coaxial jet arrangement),
the latter three.
that for the lowest swirl number (S - 0.26)
the angular momentum flux and is
the flows of higher swirl number. 319
have been selected as
recommended
The
However,
displays too large a
only as a back-up case for
-A
"-Ai The
three flows
momentum
fluxes,
selected
symmetry
and
satisfy
the
internal
requirements
consistency
stresses uv and vw with the mean velocity profiles. lation
and
may
be
computed
by
a parabolic
of
of
good conservation
the
magnitudes
of
of
the
the
shear
The flowo do not entail recircu-
"marching-type"
procedure
as
in
Morse
(1980a). ADVICE TO COMPUTORS The magnitude
of
the
shear
stress uw governing
the axial diffusion of
angular
momentum is at least an order of magnitude higher than would be expected from thb of isotropic "turbulent viscosity" hypothesis. comparable to uw and vw (see Fig. uw on the development
of the
only of significance in
Despite its large magnitude,
1).
flow is
small.
calculation
procedure is
not necessary.
for flows with recirculation;
(see Figs.
small compared
ýU/ar (see Fig. 3).
uv is
the influence of
Axial diffusion of angular momentum is
the outer part of the flow
production of uv by the action of uw is radial velocity gradient
In the near field of the flow,
use
while the
to the production against the
Consequently,
This situation is
there axial diffusion is
2a and 2b),
the inclusion of uw in the not,
however,
important,
appropriate,
and the production
2
of uv by uw is comparable to, or even larger than that by -v (DU/Dr). REFERENCES Chigier, N. A., and J. M. Beer (1964). "Velocity and static-pressure distributions in swirlng air jets issuing from annular and divergent nozzles," A J. of Basic Eng., 788. Chigier, N. A., and A. Chervinsky (1967). "Experimental investigation of swirling vortex motions in jets," ASME, J. of Appl. Mech., 89 Series E, 443. Craya, A., and M. Darrigol (1967). Boundary Layers and Turbulence,
"Turbulent 197.
swirling
jet," Plys. Fluids Suppl.,
Fornoff, M. (1978). "Experimentalle und Theoretische Untersuchung von Drallstrahlen," Diplomarbeit, University of Karlsruhe, West Germany. Hellat, J. (1979). "Turbulente Stromung und Mischung in Erdgas--Diffusion Flammen mit Luftdrall," Dissertation Thesis, University of Karlsruhe, West Germany. HAsel, W. (1978). "D-allstrahlenuntersuchungen mit einem Weiterentwickelten LasserDoppler-Messverfahren," Rept. SFB 80/E/120, University of Karlsruhe, West Germany. Kawaguchi, 0., and T. G. Sato (1971). "Experimental investigations of premixed swirlIng jet flames," Bulletin JSME 14:69, 248. Keer,
N. H., and D. Fraser (1965). lent jets," J. Inst. Fuel, 519.
"Swirl,
Part I:
Effect on axisymmetrical
turbu-
"Untersuchung Isothermer Turbulenter Drallfreistrahlen und TurbuMaier, P. (1967). lenter Drallflammen," Dissertation Thesis, University of Karlsruhe, West Germany. 320
F1
6'%-
Mathur, M. L., and N. R. L..MacCallum (1967). swirlers.
"Swirling air jets issuing from vane
Part 1: Free jets," J. That. Fuel, 214.
"Axisymmetric fre~e shear flows with and without swirl," Ph.D. Morese, A. P. (1980a). Thesis, University of London. "An evaluation of data for flow. with swirl--Flow 0340," preMorse, A. P. (1980b). pared for the 1980-81 Stanford Conference on Complex Turbulent Flows. Pratte, B. D., and J1. F. KEFFER (1972). Eng., 94., Series D, 739. Ribeiro, M. M., and J. H. Whitelaw (1980). Fluid Mech. , 96, 769.
"The swirling turbulent jet," ASIJ
ai
"Co-axial jets with and without swirl," J.
"A swirling round turbulent jet. Rose, W. G. (1962). ments," ASME, 3.Appl. Mech., 2.9,Series E, 615.
Part
I: Mean.-flow measure-
"Turbulence measurements in swirling Syred, N., N. A. Chigier, and J. M. Beer (1971). recirculating flows," Symposium on Internal Flows, University of Salford, Paper 13, B27.
321
04
-
-4
-'4
-4
1-
0'
0
0
:33
I
'C-. 00
0
~
0
-4
~
~
~0
.
0-4 04
0
gu
8
004
'
v
l)
*
0 0
,.ý
'.4
C
0.
0
000
00
c o0
6
0
0
-4
1
04ý4 0)
0
4 Q)
0.
0.
0.
0)
Q)
-4 co
U4
0
...
',
(d CL0
t 0.
o
-4.
vj
.
a m
0 06
0
V4
( Ca.
0
0
C
0
4C 0
x
0
0
0
0 '0 0
0
0.
to' W
00
&
0
SXr
0
0
-
0 L0
0
0.ý 3
~0
V) 14
co
w
m4
S,
c
-44
d
t.
U,
tv
ýocoC:
CO
co
,C4oo -4
r--1a0"
0
4.4
o
0
p'
U)~L
0
C \O
IS -4
0
0 0
-
0
tvr r, 0)
44
C
1
-
C
c
-4 C
c
ca m
~
C'
-4--
2
4
0 -ol mc
l
44
04
w'
0-
0'
tJ'-
I-
-
.
40
-".. W-
.C
w0IO
c
00 -0
~ -C
4
ca
Ci
0) ý'
.4-
-
c
0
C
'
f
~-
'."-322C
r
1
z
00
0
a
4
O t)-
..
0.
3
0
TABLE 2
Showing Standard Deviations in
Summary of Principal Test Cases Examined,
Momentum Fluxes and Swirl Number Swirl Number Author(s)
Variation in G
Variation in Ge
Variation in S
o (%)
a (%)
Quoted Value
Mean Computed Value
o (a )
-
0.23
8.3
Rose (1962)
18.5
11.6
Range of Profiles Measured (x/D)
0.235-15.0 1.0-J0.0
Pratte and Keffer (1972)
0.30
0.26* 0.35
16.0* 19.9
,4.4* 29.1
41.6* 38.7
H6sel (1978)
1.00 1.30
1.33 1.70
8.9 15.5
20.8 22.5
12.8 16.3
Fornoff (1978)
0.50
0.53
16.9
28.1
21.4
0.25-40.0
0.40 1.10 2.20
0.40 1.15 2.28
6.8 4.2 5.0
6.0 4.2 3.9
7.4 4.2 8.4
0.56-2.79
0.26
0.31
8.2
6.0
3.3
0-6.0
0.25 0.32
0.26 0.32
11.9 2.1
19.6 2.8
11.8 3.9
0.5-15.0 1.0-20.0
0.40
6.9
10.2
9.1
0.5-15.0
Ribeiro
and Whitelaw
Hellat
(1970
Ribeiro and Whitelaw (1980) Morse (1980a)
(finite
U_.)
0.36 denotes without turbulence
terms.
0.025
-'/
2
\:
0
1.5
1.0 r/rL
-0.025-•.
uv ;
A Figure
1.
Shear-stress levels S - 0.31. (1980),
at
x/D
3
vw ;
-
1.0,
6
uw
6.0.
Data
of
323
'-':"~~~~~~~~~~~.......... -"'-'" "....."."""..-".."...."...-..-i.
.""
."
"-.-'"
-. !
'
..
0.15
(iN
-[-W
*-
V-,<w
rv)-
1.',
r
p
0..0
ax
,
r/r
."
-0.05
Figure 2.
(a) Angular mnomentum balance at
Morse (1980a), S k
0.40. 324
x/D
-0.5
and
(b) at x!D
4.0.
Data of
0.021
0.5
101.5
r/r
P-(1)
Figure
3. Components of S -0.4.
-yz-L-
production of
(i i)
2-uw
uv
at
(ii10 uv
xID
-2.
0.
Uata
of
Morse
(1980a),
325~
--- --
- - -- -- - - - -
-
-
-
-
-
-
-
-
-
-
-
-
--
-
d
~~SESSI0IW
Chairman:
VIIiI
L. W. Carr
Technical Recorders: B. Afshari F. A. Dvorak
Flow 0360/0390 Flow 0380
Flow 8500
Flow 8100/8200 Flow 8400 Flow 8410
326
WAKES OF ROUND BODIES Flow 0360 Case 0361
|
AXISYMMETRIC BOUNDARY LAYOR WITHSTRONG STREAMWISE AND TRANSVERSE CURVATURE
Flow 0390 V. C. Patel*
Evaluator:
SUMMARY In
the
near-wakes
evaluation
of elongated,
be classified able not
data in
Third,
the
boundary-layer
to
and
other
body
theory
the
flow in
exists over the tail
of
emphasis
for several
has
been
reasons.
placed
First,
cases
with
large regions
for separated
and
thf
a result
gradients
is
region
of
the
quite
Second,
are
floi.q are being considered
for
body thickens which
transverse
and
rapidly
available
Consequently,
longitudinal
the body and in
the near-wake;
a complex
the
curvature
turbulent
the entire region
over
first-order
The upstream effects
the near--wake.
reli-
of recirculation,
over
large.
the
on
tar wakes can
and can be dealt with separately.
layer over a long slender
as
normal pressure
influence
test
length,
fails
data,
of bluff bodies,
The boundary
5-10% of
wake
bodies
shear layers,
the near-wakes
the Conference.
effects
axisymmetric
otreamlined
as simple
available.
rear
of
continue
shear
is
flow
characte-
rized by strong viscous-inviscid interaction. LCRITERIA Before embarking suitability determine its turbulent tion
for
on
flows,
shear further
a detailed review of any particular as a test case for calculation aethods
the criteria
in-depth
review are
meet the following criteria (a)
The
4
in .tial
case of vided cne
include,
and
Only
of
a
just downstream of least,
the
in
must the
round body, either
in
making a preliminary
those data
sets which
be well
initial
documented.
conditions
variation
of
The
The
data
contain
information
velocity
on the
belief
the
generally
held
of Hydraulics
Research,
University
stems
Iowa Inst.
must
from
the
may be pro-
boundary conditions or
pressure
of the wake and th.* pressure distribution over the tail (b)
In
the boundary layer over the body or in
the body.
327
that
near-wake. a
of Iowa,
of
at
should
the edge
the body.
This requirement
round wake
hecom,'c
Towa
[A
City,
selec-
appeared
further.
boundary conditions
the wake
at
listed.
were considered
by measurements
wake
that were utilized
set of wake data to developed for complex
fully
52240.
to
developed and attains near self-preservation within a distance of the order of one or two body diameters and that the subsequent wake flow can be treated adequately which are restricted
to
by thin sihear-layer
the far wake are
approximations.
therefore not
Data
suitable as
test cases. (c) The
measurements imust
velo.city
as well
minimum).
profiles
of
turbulence qusntities
both
pressure
(Reynolds
and
mean
stresses,
at
a
The flow in the near-wake qualifies as a complex shear flow
due to the body
as
include
influence of the extra rates of strain
curvatures),
higher-order
boundary-layer
(generated by the
effects
(i.e.,
normal
pressure gradients), localized separation, and viscous-inviscid interaction.
Fairly detailed data are therefore required in order to test
the performance of calculation methods in this environment. AVAILABLE DATA Rodi wakes.
(1975) Although
revie~~ed his
prestzrvation aspects, were
data
review
from was
it indicated
several
critifined
previous '.argely
that most of the
experimenits to
the
in axiaymmetric
Raymptotic
and
data aVa 4 lable up to that
selftime
acquired in the wakes of bluff bodie& with Large regions of recirculation and
were confined to large distances downkstreami of the body. include turbulence measurements.
The only exception to this wap the data of Chevray
(1968) in the near-wake of a prolate spheroid. velocity
and Reynolds
Furthermore, several did not
Chevray's measurements included mean
stresses at a station upstream and at several stations down-
stream of the small region of separated flow at the tail.
This data set could form an
ideal teat case for boundary-layer calculation methods designed to handle small pocketa of separated flow (so-ca1lL3 inverse calculations) and extend into the near-wake, and was therefore examined in detail. Interest
in axisyminetric wakes has
increased in recent
vears due
to possible
naval applications, and several new experiments have been reported since Rodi'a review.
Schetz et al.
have made mean-velocity and Reynolds-stress measurements Ili the
wakes of three bodies of revolution. 2 < x/D < 40 the body. *
In all cases, data were obtained over the range
where x ts the distanc~e from the tail and D is the niaximuin diameter of
The mean-velocity profiles indicated near self-similarity over this region.
Consequently, regioas.-
,
it was concluded
Furthermore, nu
that
the data do not include the
Information
important near-wake
is available either on the bounda-ry layer over
the body or the condition of the flow at the tail.
These data therefore di(: not sat-
isfy the established criteria. The body has
boundary layer
over
been investigated by
tne tail
of
a streamlined,
Patel et al. 328
(1974).
sharp-tailed,
In fact,
axisymmetric
they modified thec 6:11
by
a
attaching
to eliminate
conical tailpiece
Although their detailed measurements were confined
separation. layer,
(1968)
model of Chevray
spheroid
the
to the thick boundary
they may be of interest in wake studies since the flow over the tail possesses
many of
of
the features
thereforc
the modeling of
in
importance
Their data may
near-wakes.
calculation proce-
be useful in testing boundary-layer as well as near-wake
dures and have been evaluated. (1978)
arid Huang et al.
The more recent experiments of Patel and Lee (1977)
have
included not only the thick boundary layer over -he tail but also the near-wake. they provide static-pressure, mean-velocity, and Reynolds-stress data on Tqgether, bodies with different
three different
and boundary-layer histories.
surface-curvature
These were examined with a view to determine their suitability as tegt cases. the following sets oE axisymmetric flow data were evaluated:
In suammary,
Chevray (1968), Patel et al.
Spheroid; Modified spheroid;
(1974),
Low-drag body;
Patel and Lee (1977), Huang et al. After (1980),
of
completion
the
Afterbody I and 2.
(1978),
a
these reviews,
by
report
preliminary
describing yet another data set on a third body of revolution,
et
Huang
al.
was received.
Although this appeaus to address some of the criticisms of the previous measurements, a detailed evaluation could not be carried out within the required time frame. RECOMMENDATIONS Detailed
evaluations of
the five data sets are contained
in
the Review Report.
The resulting recommendations are summarized below. (a)
The
uncertainties which (b)
The
and Huang et al.
data of Patel and Lee (1977)
metric
of Patel et al.
data
(1974)
since
the
measurements
are recommended
rather than for axisym-
for complex wall shear layers
near-wakes
contain some
make them unsuitable as test cases.
thick-boundary-layer
as a test case
(1978)
were
not cortitnued
into
the
should
be
wake. (c)
The
recenly
considered (d)
completed
(1980)
in future evaluations. of Chevray
The measurements data
measurements of Huang et al.
(1968)
represent
by far the most complete
set in the wake of a streamlined axisymmetric body and id recom-
mended
as
a
test
case.
The
static
pressure,
mean
velocities,
and
Reynolds stresses have been measured with acceptable accuracy and the flow
is
judged
interest since near the tail.
to be axisymmetric.
As a test
case,
it
it
of special
it contains a small embedded region of flow reversal It is suggested that the calculations start from the 329
boundary layer over the body, near-wake, ;
Starting mended
*
1972,
to the far wake.
the solutions
at the
since the effects
already
significant
at
of
first measurement normal
pressure
this station.
station,
gradients that,
Note
where this data set was used as a test case,
stream of the separation bubble. *•
continue through the separated flow and
at
x/D - -0.25,
and transverse
is
not recom-
curvature
are of
the NASA-Langley Conference
the calculations were started down-
This is not recommended for the present Conference.
COMMENTS FOR FUTURE EXPERIMENTERS The
crucial uncertainty in data of this
Saxial symmetry,
particularly since
adequate documentation of
type concerns
several investigators have reported that
the flow
over the tail of the model and in the near-wake is quite sensitive to small changes in model alignment
and mounting aýrangement.
.
culties
"
boundary layer and the near-wake.
of
mnking
accurate
measurementE
Another uncertainty stems from the diffiof
static
pressure
These are especially
of
the
subsequent data
flow at
a
well-defined
are to provide
initial
a measure of
rates of strain and normal pressure variation. tutes a "~near-wake- (or
thick
tail
A comprehensive documenis
the influence
the
in the quantifica-
also
important
if
the
of such factors as extra
the question of what consti-
the approach to asymptotic conditions) and how it Is influ-
enced by the initial conditions
(i.e.,
the tail or separation over the body) tional experiments
station
Finally,
across
important
tion of the overall effects of viscous-inviscid interaction. tation
V
are needed,
some of the points which sh
whether the wake starts from Attachea
flow at
cannot be answered with the present data.
including measurements
in separated
flows.
Addi-
These are
id be addressed in the design of future experiments.
REFERENCES
:
"Chevr4,",
R. (l%6°). "The turbulent wake o 2i3- 2 8 4 (see ilso Ph.D. Thesis, The Uni
round body," ASME, if Iowa, 1967).
J.
Basic
Eng. , 90,
Huang, T. T., N. Santelli, and C. Belt (1978). "Stern boundary-layer flow on axisymrmetric bodies," Proc. Twelfth Symp. on Naval Hydromechanics, National Academy of Sciences, pp. 127-157. Huang, T. T., N. C. Groves, and C. Belt (1980). "Boundary-layer flow on an axisymmetric body with an inflected stern," Preliminary Report, DWT-NSRDC. Patel,
V. C., A. Nakayama, and R. Damian (1974). "Measurements in the thick axisymturbulent boundary layer near the tail of a body of revolution," J. Filid Mech., 63, 345-362 (see I1IR Report No. 142, 1973, for tabulated data).
Sm.tric
Pattol V. C., and Y. T. Lee (1977). "Thick axisymmetric turbulent boundary layer and near wake of a low-drag body of revolution," Iowa Institute of Hydraulic Research, "The University of lows, [1HR Report No. 210 (see also Turbulent Shear Flows, Vol. I, pp. 127-153, Springer-Vorlag, 1979).
"330
Rodi, W. (1975). "A review mf experimental data of uniform density free turbulent boundary layers," Studies in Convection, B. E. Launder, ed., Academic Press, pp. 79-165.
DISCUSSION Flows 0360/0390 The Conference
1.
agreed that
the data of Chevray
should form the test case
(Case
0361) for the wake from a streamlined axisymmetric body. 2.
At the suggestion of T. T. Huang it
"be left
was agreed that the data for Flow 0390 should
for future evaluation.
331.
-I-
i."..331
•
"'"-..a.-
>..-
.•.--
.
....... "
........
...
....
...
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE V.
Data Evaluator:
Case #0361;
R.
Data Taker:
C.
Patel
Chevray
FPIC'IQtJ Al. S.IO4AI 1Fow 0)60.
Date Iv..Lwatrt
NSak"e at ro-W. Bodies
V. Patela.
T-I-
Velocity
T.ler
Dati
C""eeat lis
Ge
Goommtry
C
-t
c""
I
-2
V
u.n l l 12a
12
12
2.75 106
-
i
io-s.
Fr..
l~Sel
,enrc* 0.2%
Isttic pressure dLetrlbk tO ,Q, ti-n scr .aatlk eis
2.q2
*
O,214.
IurfAc* preamur.
*..K1odal
.0
Pat.
.h.,
Oter
12 1l
lackL
Wakes).
o
Ges0)41
t
(ketayieetrlc
M4easured
I*iMter at Ststaw
mat ....r.d. a 0 -.
Comments
Range/Position
Abscissa
Ordinate
Plot
2
zC
= PA/qref
2
r/Rref
U/Urn
0 < r/Rref <1
5 curves at X/Rref 2.0, 6.0, 36.0.
r/Rref
(uv)/U2,
0 < r/Rref < 1
5 curves at
0 < r/Rref
X/Rref -5 curves at 2.0, 6.0, 36.0. rf
r/Rref
2
(u
r/Rref
4
"i
I/0'
0 < r/Rref< 1
) 1 / 2 /U0 .
5 curves at 0.5, 1.0, 2.0.X/Rref ref
2.0,
6.0,
X/Rref
-0.5,
0,
-
-0.5,
0.5,
-
-0.5,
0.5,
0.5,
0.5,
36.0.
.,
6
r/Rref
(2 ) 1 /2/Uon
0 < r/Rref < 1
5 curves at X/Rref 2.0, 6.0, 36.0.
-
6
r/Rref
(wi")1/2/U.
0 < r/Rre
5 curves at X/Rre 2.0, 6.0 , 36.0.-.
-0.5,
S--
--
Special Instructions: Due
to
attempting mental advised (Y/L-
the this
separation case
information
required
in matching -0.0417,
will
X/R
bubble use
at
by S.
(compiled
the
tail,
interactive
or
is
it
-
-0.5)
solution
that
li-
0,5,
.•
most cal,- ilators
procedures.
should be minimal.
the calculations with experiment
0.5,
Kline)
expected
inverse
for such calculations
J.
-O.5,
5
since the first
Expert-
Some caution
is
measuring station
is Just ahead of separation. 332
a..
-m
It
is
suggested that the influence of the transition device be taken into account
by matching the calculations at
X/L
-0.314
-
with the boundary-layer measurements of
Patel et al. after scaling the latter data for t]L
difference in
the Reynolds numbers
of the two experiments. This is recommended since the same model was used in both, and the boundary layer at the match station is expected to remain unaffected by the small change in
tail geometry shown on Fig. 2 below.
This expectation is confirmed by
rescaling and plotting the displacement thickness lines for the two cases, Fig.
3 below (computations
by V. C. Patel).
as shown on
Regarding these computations,
Patel re-
marka that he has accomplished this (scaling] as follows: (a)
the integral parameters R8 , H, Cf,
and
6/rO have been
scaled using proper
relations to obtain corresponditig values of the higher Re of Chevray; (b)
since the velocity the Coles (scaled)
profile
profile of Patel et al. family,
this has
integral parameters
are listed in
detail
in
been
is
in
excellent agreement with
used in
conjunction with the new
to obtain the velocity profile.
the
accompanying
Both profiles
computer output (Tables
I and 2
contain profile data as supplied by V. C. Patel); (c)
since the Reynolds-stress measurements of Patel et al. Klebanoff
(see J.
Fluid Mech.
together with the proper Ue, BY THE COMPUTOR.
paper, Cf,
Fig.
12),
agreed with those of
this information can be used
and 6 to obtai.n the stresses,
IF REQUIRED
uv distribution is also given in the computer output.
UE
V
~
!Li
1k . (x/L)c
L -body
length -60";
R
max. body rad -10"; -
Figure 1.
Notation for Case 0361. 333
D
*2R
I,
i
.
~L W REVERSAL
PROPOSED STARTING STATION X/D ,-1.884
CHEVRAY (1Q68) DATA POINTS WD)
U
U')
SPHEROID-
CHEVRA Y"--:.. . .
•
•J(
.o
CS
C
0 00
to
PATEL et &1,
DATA POINTS (x/L)
Figure 2.
0.7 1
0 .4 -
NO REVERSED FLOW ANYWHERE
Changes in tail geometry.
o CHEVRAY PATEL et a&.
0.6 -
:'.0
0)
0
o 0a
600
.0
.3
;:0
0.2"
0.3
.1
30
40 PROPOSED-.-
50
60
x INCHES "FROM NOSE
MATCH iSTATION
TAIL OF CHEVRAY SPHEROID
*..
Note;
Figure.
3.
D"iplaCewOnt
aurf&ce to oaren,
U.ncertRAnty,
in both expertients.
ulthin
_-O
t TAIL OF PATEL et al. BODY
;-
el-xpeimental.
Distance to the displacement surface from the axis. 334
L4 - .-
•~
. ,
. - . .
,-
• .
-
-.
- -.
-
-
-
-
.
.
.
.
.
.
X/L UE, M/8 RDELS
Profile Data (Patel et al., 1974) TABLE I. 0.662 (Nomenclature follows standard computer symbols, 12.00 1767 Y, mm
DELS, CF
m
0.00221 0.0034
U/IE
HS DEL,
KAY/UE
m
pp.
iii-v)
1.455 0.01790 -UIVI/UE**2
0, 000
0. 000
0.000000
0. 000000
0.321 0.342 0.364 Q.389 0.416 0. 444 0. 476 0. 509 0. 546 0. 586 0.629 0.676 0. 726 0. 782 0. 842 0. 907 0,980
0.35" 0.370 0.383 0.397 0.410 0.423 0.437 0.451 0 465 0. 479 0.494 0. 508 0. 523 0.537 0. 552 0. 563 0. 571
0.005667 0.005667 0.005667 0.005667 0.005667 0.005667 0.005667 0.005667 0.005667 0. 005667 0.005667 0.005667 0. 005667 0.005667 0. 005667 0.005667 0.005666
0.001700 0.001700 0. 001700 0. 001700 0.001700 0.001700 0.001700 0.001700 0.001700 0. 001700 0. 001700 0. 001700 0. 001700 0.001700 0. 001700 0.001700 0.001700
1,09
0. 578
0.005665
0. 001700
1. 147
0. 586
0.005664
0. 001699
1. 244
0. 595
0.005661
0.001698
1.350 1.468 1. 598 1.741
0.603 0.612 0.620 0.629
0.005656 0.005650 0.005641 0.005630
0.001697 0.001695 0.001692 0.001689
1. 898
0. 638
0.005615
0. 001685
2.072 2. 2163 2.474 2,706 2,962 3. 243 3. 353 3. 895 4 270 4. 682 5. 136 5. 634 6. 180 6. 780 7.437 8, 157 8. 945 9. 806 10.748 11.777 12. 92 14. 133 15, 481 15 962
0.648 0.657 0.667 0.677 0.687 0.698 0. 709 0.720 0.732 0.745 0. 758 0.772 0. 786 0.802 0.818 0.835 0.854 0.873 0.893 0.913 0.934 0.954 0.972 ( 98E
0. 005596 0. 005572 0.005541 0.0055('3 0.005455 0.005396 0. 005324 0.005236 0.005130 0.005002 0. 004850 0.004669 0.004456 0.004207 0.003920 0.003591 0. 003220 0.002807 0.002356 0 .6.t877 .,1384 0.000900 0.000465 0.000136
0. 001679 0. 001672 0.001662 0.001651 0.001636 0.001619 0. 001597 0.001571 0.001539 0.001501 0.001455 0.001401 0 001337 0.001262 0.001176 0.001077 0.000966 0.000842 0,000707 0.000563 0.000415 0.000270 0.000139 0.000041
18. 595
1. 000
0.000000
0.000000
, -,.
335
I...
TABLE 2. X/D
UE, M/s RDELS
-
-1.884
27.43 3369
Profili Data (Chevray,
(Nomenclature
DELS,
m
CF
Y, mm
1968,
follows standard
U/UE
after re-scaling)
computer symbols,
0.00184
HS
0.0030
DEL,
KAY/UE**2
pp.
m
0.01528 -UlVI/UE**2
0.000
0.000000
0.000000
0 148 0.159
0.334 0.348
0.005000 0.005000
0.001500 0.001500
0.171
0.362
0.005000
0.001500
0. 184 0.199
0.376 0.390
0. 005000 0.005000
0. 001500 0.001500
0.214 0.231 0.250
0.404 0.419 0. 434
0.005000 0.005000 0. 005000
0.001500 0.001500 0.001500
0.271
0.449
0.005000
0.001500
0.293 0.318 0.345 0.375
0. 464 0.479 0.495 0.510
0. 005000 0.005000 0.005000 0.005000
0. 001500 0.001500 0.001500 0.001500
0. 408
0. 525
0. 005000
0.001500
0. 444 0. 485
0. 0.
533 541
0. 005000 0. 005000
0. 001500 0.001500
0. 530 0. 581
0. 549 0. 558
0. 004999 0. 004998
0.001500 0. 001499
0.638 0.701 0. 772 0.850 0.936 1.037 1. 146 1.269 1. 406 1.558 1. 729
0.567 0. 575 0. 584 0. 594 0.603 0,613 0.622 0.632 0.642 0.652 0. 662 0.673 0. 684 0. 695 0.706 0.718 0.731 0.744 0.757 0.772 0.787 0.604 0.821 0.840 0. 860 0. 881 0.903 0.926 0.948 0.969 0.987 1.000
0.004997 0.004995 0.004992 0.004988 0.004'983 0.004976 0.004967 0.004955 0.004940 0.004921 0. 004897 0.004866 0.004828 0. 004780 0.004720 0. 004645 0.004554 0. 004442 0.004306 0.004141 0.003944 0,003710 0.003434 0.003114 0. 002"747 0. 002336 0. 001867 0. 001412 0.000933 0.000490 0.000146 0. 000000
0.001499 0.001498 0.001498 0.001496 0.001495 0.001493 0.001490 0.001487 0.001482 0.001476 0. 001449 0.001460 0.001448 0.001434 0.001416 0.001394 0.001366 0.001333 0.001292 0.001242 0.001183 0.001113 0.001030 0.000934 0.000824 0.000701 0.000566 0.000424 0.000280 0.000147 0 000044 0. 000000
1.919
"3.623 4.031 4.486 4.991 5.553 6.176 6.868 7.634 8.483 9.422 10.461 11.611 12.886 14.302
"15.884
3Y3
-Ii
-"
1.405
0. 000
2.132 2.369 2.633 2.928 3.257
iii-v)
'--
.
.1 -A
-1
.
L*.
,PLOT "xrf -0.
1 CASE 0361 FILES 2-6 0
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PLOT 3 CASE 0361 FILES 61,63,65,67,72
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(w2 ) 1/ 2 /T'C PLOT6FLFS 961 -4 X/Vf
0.
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2.06.0 3309
0I -
. ..
- .
-
.4........
.
.
.
C,
WAKES OF TWO-DIMENSIONAL
BODIES
Flow 0380 Evaluator:
V.
C.
Patel
SUMMARY
Extensive measurements dimensional
"upon -
The
distance
available
from the
body:
wakes,
characterized by
tions,
such as pressure gradients
have
S-'
the
bodies.
have been made,
on
been discussed
the influence
are
available
1972;
and
"smAll"
of externally
Prabhu,
fully developed
1971).
These
turbulence models.
the
imposed
example,
to
far
into wakes
three (or
(b)
literature
broad
or
of
The present survey,
in
however,
is
developed)
and
Far wakes
(c)
near wakes.
are not considered here.
1972;
connection
and may
fully
pCLurbd-
Prabhu,
interest
perturbations
depending
far wakes tubjecLed LU
and
and
the wakes of two-
categories,
pressure gradients on far
Narasimha are
in
asymptotic
or stratifications, in
for
turbulence
(a)
fall
v-lnA.1.y ýcfecti,
extensively
(see,
data
over several decades,
also
(small-defect)
Prabhu with
and the
provide good
Data wakes
Narasimha, response
test
cases
of for
confined to near wakes.
REVIEW OF NEAR-WAKE DATA The available
near-wake
data can be subdivided
of the body geometry and the flow conditions at '-
reviewed in
into five categories on the basis
the trailing
edge.
There
present a number of
These are briefly
turn.
Symmetric Wake of a Smooth Flat Plate This .
sets
of
is
"Kovasznay, Solignac, five of
".
the simplest
incompressible 1969; 1973; these.
of near-wake
flow
Fayet
et
data
in
al.,
fluws.
this
1971a;
and Tsen and Fayet. The major features
category
1971b;
1971).
are at
(Andreopoulos,
Pot,
1979;
of the models,
and zrailing-edge
are
appear to cover
a wide range of Reynolds number and initial
edge.
in
the
Ramaprian
Chevray
et
Quire detailed information is
characteristics
summarized
1978;
Review
Report.
Together
data
al.,
and 1980;
available on
and boundary-layer these
experiments
conditions at the trailing
We shall return to these data later on.
Symmetric Wakes with Pressure Gradients In
this category we may consider the near wake of a flat
imposed pressure gradient
or wakes of airfoil-like
plate •Jth
an externally
bodies with self-induced longitudi-
nal pressure gradients. Among the data of et al.
(19
7
1c;
1972a).
streamwise pressure
the first
kind are those of Chevray and Kovasznay
who rene~ted
their
r'"
..- .
•
..
a fI>L •Tahe
gradient imposed by contoured sidcw1llz
340
•
nts
kig69)
iith an adverse
-
Visnawath et al.
(1979)
have made measurements in the boundary layer and the wake
of a model consisting of a flat-plate middle body, edged symmetric aft
flap.
a rounded nose section, and sharp-
With no flap deflection,
bles that of a thin airfoil.
In fact,
Chevray and Kovasznay
Fayet et al.
(1969),
the wake is
this experiment is (1971a),
symmetric and resem-
somewhat similar to that of
and Teen and Fayet (1971),
but it
has been included here since the pressure gradients over the trailing edge are significant.
There are
two data sets,
*.
ments
..
velocity profiles in
include
stations in
static-pressure
corresponding to
distributions
on
and Reynolds stresses u 2 , v,
the wake.
The early
the
model
and
and the measure-
tunnel
walls,
mean-
the boundary layer on the aft portion of the model and at several
This data net is being reviewed by P.
tions.
M - 0.4 and 0.7,
measuremento
of
Preston
incidence also fall in this category,
and uv at most of the above sta-
Drescher.
and
Sweeting
on a
Joukowski airfoil
at zero
but these were restricted to static-pressure and
mean-velocity traverses. Asymmetric Near Wakes There are many data sets in this category.
M. Firmia of RAE reports that several
--
recent data sets from two different airfoils (RAE 2822 and RAE 101) are available over a
range
mean
of
incidence,
flow measurements
contained in the latter,
Reynolds using
number,
pitot
RAE TM Aero 1725, Cook et al. (1978)
and Mach number!,
and static
RAE TR 71127,
tubes.
but are The
all
relevant
restricted
to
Information
is
and AGARD Advisory Report No.
is
believed that
in the aircraft
.
"
In
provide a detailed account of the data and their accu-
racy for the measurements on the RAE 2822 airfoil at several values of Re, It
138.
•
-4
M, and a.
similar data on other airfoils have been gathered over the years
industry and related research establishments,
but the evaluator is
not
aware of corresponding turbulence measurements. The
study
of
Visnawath
asymmetric-wake
data,
of
measurements3
6.50.
stress
The
(u0,
V2,
et
al.
(1979)
referred
to
earlier
include
static
pressure,
mean
velocities,
one side.
and Reynolds
(1971c;
1972b)
describe
the wake of their flat-plate model fitted with sandpaper roughness on
the wake was also subjected
gradient by
provides
uv).
Two sets of asymmetric-wake data gathered by Fayet et al. measurements in
also
since one experiment was performed with the aft flap deflection
leans of contoured
to a symmetric
sidewalls.
The last
hdverse longitudinal
pressure
in this series of reports
(Fayet
7
et al. , 19 2c) describes experiments in the asymmetric wake of the smooth flat plate at an incidence of 100. In all cases, the data include static pressure, mean velocities, and Reynolds stresses. Thc most recent, have
been
carried
out
and perhaps the most detailed, by
Andreopoulos
(1.978)
341
and
measurements Ramaprian
et
in asymmetric wakes al.
(1980).
Both
p.-
Ii on
utilize
roughness
data
from the former
one
of
side
a
model
flat-plate
have been reviewed,
expe-iment
to
the
realize
asymmetry.
The
from the lattey
while thuse
are
undergoing analysis.
still
Finally,
their wake
Ramaprian et al. are continuing
by making measure-
studies
the wake of a super-critical airfoil at moderate incidence.
ments in
This experiment
will be completed during the fall of 1980. Infinite Swept-Wing Wakes The evaluator
cross
boundary layer
The
18-l/2°•
flows are
of the order is
three-dimensionality
in
top surface
on the
of 40*.
The
this category.
Cousteix et al.
swept at 22-1/2,
at an incidcnce
is
close
to separation and
the
top and bottom asymmetry is
high and the
include pressures,
mean veloci-
The measurements
also large.
A preliminary report describing the experiment
and the six Reynolds stresses.
ties,
rimento
-x
in the wake of a wing,
have made measurements
(1979) of
aware of three
is
and data is now available. The experiment of Bradshaw
et
al.
(1980)
is
to the above and is
similar
that the wing consists of
Preliminary information received thus far indicates
gress.
The angle of sweep is
a contoured upper surface and a flat lower surface.
in pro-
QuIte
35°.
detailed measurements are planned for the region downstream of the trailing ,.dge.
It
is expected that a complete data set will be available soon. The third set of data is due to Cook et al.
(j979),
and static pressure through the wake
flow dlrection,
the distributions of Mach number,
who have made measurements of
and boundary layer of a wing of constant chord and RAE 101 section at sweep angles of and incidences of ± 1.880.
20 and 28,
turbulence data were not collected.
However,
Wakes Starting with Flow Separation involving
Near-wakes Nevertheless,
it
separation
flow
not
have
been
reviewed
in
detail.
obtained with geometries
that more and more data are being
appeers
here
involving separation. A recent
by
report
(1979)
the flow over
to simulate
apparatus
Solignac
with sepaiation on the upper surface.
describe3
measurementa
in
an
axisymmetric
of a two-dimensional airfoil,
the trailing edge
Hot-wire and laser anemometry hah been used to
maasure the mean and turbulence velocitlec,
but it
appears that the resolution of the
measurements in the separation zone is not complete. Young
and
Hoad
(1979)
have
reported
two sets of
NASA measurements
on
stalled
airfoils using laspr anpnmprry. SELECTION OF TEST CASES Ideally, each
of
the
it
is
five
desirable to have available one reliable and complete data set in classes
of
wakes
two-dimensional
listed
above.
As
tho
summary
342
.. .?-•. ... . ,'-. ,...:i- . .. - . .... .. -.."•
'• "
= •-'"
; : "-
'
r',
'
-
. -''-•""""
'
.... i
"'.
.....
_:-.
.
"-:
- - - •-•
-•
•
indicated,
however,
of evaluation ments are wao
there are many data sets in
each category and therefore the task
and selection is quite considerable.
either in
started.
progress
A decision was
Furthermore,
many
of the expert-
or were completed well after the present
relew process
therefore
from
made to examine only
the data
the mont
simple experiments first in the hope that the others will be evaluated later on.
The
cases
the
selected
for evaluation were:
(a)
the wake of a smooth flat plate and
(b)
asymmetric wake of a flat plate roughened on one side. The criteria used in the qelection of test cases are as follows: (a)
Fully developed (R 0 > 3000, say) turbulent boundary plate, so that low Reynolds number effects arc absent.
(b)
Well-documented initial conditions, the plate or at the trailing edge.
(c)
Sufficiently detailed data in the near wake, mean velocity and Reynolds stress profiles.
(d)
Acceptable level of accuracy and two-dimensionality.
either
in
on
the
layer
on
layer
the boundary including at
least
the
AVAILiBLE DATA Considering
first
(1978).
Chevray and
(1980),
Solignac
the
wake
Kovasznay
(1973),
of a
(1969),
smooth Fayet
flat
et al.
and Tsen and Fayet
(1971)
plate,
the
9
(1 71a;
data
of
1971b),
Andreopoulos
Ramaprian
were examined and it
et al.
was concluded
that the earlier data had been superseded by the more recent and detailed measurements of
Andreopoulos
(1978)
and
Ramaprian
(1980)
were
in
Ramapria.i et
al.
the required
time frame,
evaluation is
described
experiment of the It
et
progress,
al.
(1980).
Since
the
experiments
and the data could not be analyzed within
,)rly the data of Andreopoulos were reviewed in detail. in
of
the Review Report.
Finally,
Pot
(1979)
The
describes another
in the wake of a flat plate but the report was received in the later stages
review process and his data could not
be evaluated
in
time
for this summary.
is hoped to continue the evaluation and make an oral report at the Conference. In
the case of the asymmetric wake of a flat plate with roughness on one side,
there are several
sets of data:
and Ramaprian et al.
(1980).
Andreopoulos
Again,
(1978),
Fayet et al.
(1971c;
1972b),
only the data of Andrenpoulos have been evaluated
in detail. RECOMMENDATIONS Lne
detail-d evaluation
r-ted t'hat is
of the symmetric-wake
qre suitaole as a test casc.
tl-
data of
Pot
(1979)
profiles,
The
latter show that
.-
-
-
where we hope to recover the
-
-*,
the growth and decay rates,
do not reach asymptotic conditions until
343
-
indi-
This drawback did not come into focus until the recent
were examined.
and the Reynolds-stress
(1978)
i'crhapb the only limitation of the data
that the measurements do not extend into the far wake,
classical asymptotic solution.
..
data of Andreopoulos
x/O
-
400,
it
this,
is
for
to
is
the
replace
provided an evaluation of It
criteria.
data
that calculationH
also suggested
is
confirms their
data
the latter
,
Andreopoulos
of
the prohlem of con-In,'ing the calculation through the discontinuity in
the bound-
Here
a
test
theory
in
the
far wake.
of
the
the
plate),
case.
the
just upstream of
of
which
is
again recommen-
the data of Andreopoulos are
calculations
should in
uncertainty from
(resulting
edge
trailing
influcnce
also
case,
An additional
the near wake.
in
layer
boundary
to the asymmetric
as
thickness
the
faced squarely.
is
With regard
ments
1000,
x/O -
edge so
in
start
case
test
ary conditions
ded
up to
of
view
the trailing
this
that
In
40t
x/O
400 < x/e < 1000 be compared with the results
alternative
to the othe:
reLative
acceptability
to
for this case be continued
the range
uase,
Pot as a test
those of
up
only
extend
Andreopoulos
in An
theory.
asyieptotic
of
that calculations
suggedted
the predictions
and that of
measurements
the
whercas
evident
also
stems
sandpaper in
peaks
with
compared
this case
the
from the are
Similar results
be
the
from the
one
on
asymptotic
of
side
turbulence
the symmetric-wake
seen in
finite the
measureexperi-
edges were not in which the trailing ments of Ramaprian et al. (1980) and Pot (1979), Calculators would need to be cognizant of model. as sharp as those of Andreopoulos' this influence of
conditions and it
initial
would be interesting to see whether calcu-
lation methods are responsive to the trailing-edge geometry. REFERENCES "Symmetric and asymmetric near wake of a Andreopoulos, J. (1978). Thesis, Imperial College, London. Bradshaw,
P.,
Chevray, R., thin flat
(1980).
et al.
Private communication,
Imperial College,
"Turbulence measurements and L. S. G. Kovasznay (1969). plate," AIAA Jou., 7, 1641-1643.
Ph.D.
plate,"
flat
London. in
the wake of a
"Aerofoil RAE 2822--pressure Cook, P. H., M. A. McDonald, and M. C. P. Firmin (1978). in Experimental Data and boundary layer and wake measurements," distributions, AGARD Advisory Report 138, pp. k6.l-A6.77. Base for Computer Program Assessment "Wind tunnel measurements of Cook, P. H., M. A. McDonald, and M. C. P. Firmin (1979). the mean flow in the turbulent boundary layer and wake in the region of the trailing edge of a swept wing at subsonic speeds," RAE Tech. Rept. 79062. Cousteix,
J.,
et al.
(1979).
Fayet, J., H. Carem, and L. symitrique d'une plaque Poitiers, France.
Private communication,
CERT,
Toulouse,
France.
"Montage et exp6rience stir le sillage F. Tsen (1971a). 70/145, CEAT, plane, dana un 6coulement uniform," Rept.
"Mesure de l'4nergie cin6tique turbuFayet, J., H. Garem, and L. F. Chen (1971b). lente dans un Eillage sym~trique d'une plaque plane dans un &coulement uniform," Rept. December 1971, CEAT, Poitiers, France.
344
•
.
.
.
.
.
...
.-.-
.
Fayet, *J., j. H. Garem, and L. F. Teen (19 7 1c). "tontage et expriences aur lee sillages sym~trique et dissym~trique d'une plaque plane dans un &c KI ment avec gradient de pression," Rept. 70/145, CEAT, Poitiers, France. Fayet, J. J. H. Garem, and L. F. Tsen (1972a). siatriq;et -'.ne plpqie plane en 6coulement Poitiers, France. Fayet, J., J. H. Garem, and L. F. Tsen (1972b). dissymitrique d'un profil en 6coulement Poitiers, France.
Energie turbulente dans un sillage d6celer6," Rept. March 1972, CEAT,
"Tensions du Reynolds dane un sillage d6celer4," Report June 1972, CEAT,
Fayet, J., J. H. Garem, and L. F. Teen (1972c). "Sillage cr=e par une plaque plane inclin~e A 10* plac~e dane un gradient de preosion positif," Report December 1972, CEAT, Poitiers, France. NaraRiLha, R., and A. Prabhu (1972). J. Fluid Mech., 54, 1. Pot,
P.
J.
(1979).
"Measurements
"Equilibrium and relaxation in in
a
2-D wake
and
in
a
turbulent wakes,"
2-D wake
merging
into a
boundary layer, data report," NLR TR-79063 L (Provisional Issue). Prabhu,
A. (1971).
Prabhu,
A.,
Mech.,
Ramaprian,
and 54,
R.
Thesis,
Narasimha
B. R. ý V. C. Patel,
J.-L.
Indian Institute of Science,
(1972).
Bangalore,
non-equilibrium
20.
of Hydraulic
Solignac,
Ph.D.
and M. S.
Sastry (1980).
Research,
University of Iowa.
(1973).
"*Calcul du
sillage
obstacle minc4," Fourth Canadian Cong.,
India.
wakes,
J.
Unpublished date,
turbulent
bidimensionnel
Applied Mechanics,
en
Montreal,
Fluid FTurbulent
•
Institute aval
d'un
Canada.
Solignac, J.-L. (1979). "Etude exp~rimentale de la conflucace avec d~collement Bur un arrire-corps de revolution," Tech. Rept. 1971-151, ONERA, France. Tsen, L. F., and J. Fayet (1971). un 6coulement avec gradient France.
"Etude du d4veloppement d'un sillage turbulent dans de pression," Rept. 70/145 Final, CEAT, Poitiers,
Viswanath, P. R., J. W. Cleary, H. L. Seegmiller, and C. C. Horstman (1979). ing edge flows at high Reynolds number," AIAA Paper 79-1503.
"Trail-
Young, W. H., and D. R. Hoead (1979). "Comparison of two flow surveys above stalled wings," AIAA Paper 79-0147 (see also NASA TN D-8408, 1977; NASA TP-1266, 1978; NASA TN-74040, 1978).
I
345
...
•-- .-~..................................... ".... - .. ........ ........ -.. ..
•'~~......
. -
.'.-.--
' .- . - .
- -..
- . .- : ' -.
. .
-'-.1'',
.
.
-" .
-
"
.. -.
...
..
... -.--
•i
: .
-
'.-i .
'-" .-
_ .
" -
.
. : . -
. . ..
, -
FLOW IN THE WAKE OF FLAT PLATE WITH SY4IMMETRIC
WAKE
INITIAL BOUNDARY LAYERS
AND ASYMMETRIC
Flow 0380 Cases 0381, Evaluator:
0382
V. J.
Data Taker:
Patel
C.
Andreopoulos
SUPPLEMENT 10 SUMMARY
WAKE OF SMOOTH FLAT PLATE
CASE 0381. This
velocity
Mean
0.374,
0.187,
Reynold8
(b)
performed
in
wake
the
of a
smooth
plate
tlat
at
M
0.1.
included the following:
The measurements (a)
was
experiment
1.869,
at
profiles 0.561,
stressea
1.869,
0.935,
-, uv
u' ,
stations,
streaurvise
10
3.738,
at
0.0935,
-
and 9.35.
5.607,
6 stations,
X/6 0
x/6
0,
0
0.467,
0.935,
and 7.477.
'.738,
(c)
Triple correlations
(d)
Conditional
u
u 2 v,
, to
averages
study
v
3
the
, at the 6 stations in
mixing
in
the
(b).
central
part
of
the
wake. The following comments mation contained in
the first
concern
(1978)
Andreopoulos
three items
and are based on the infor-
(a-c)
from the experimenter.
and further inpu'
Test Facility The
experiment was conducted
speed
45 m/s,
thick.
The
450
mm
and
a
ambient leading
turbulence
edge,
long,
0.05%). was based
of 0.07 mm.
The
wind
tunnel
(maximum
The model was 3080 mm long and on
yield a sharp trailing
to
thickness
a 91 x 91 cm closed-circuit
level
80 mm
tapered
length was reported TE
in
the NACA 0009 edge,
boundary
section.
included
layer
was
TE angle
28 mm
The
rear
of
3.5°
by means
tripped
of
50-mm-wide sandpaper strips just downstream of the 80 mm leading edge. The
model
span of
the
spanned
the working The
tunnel.
and
section
leading edge of
the
was
mounted
plate was
at
horizontally
located
the mid-
"Just downstream"
of
the tunnel contraction. All tests of
the
were
conducted with a velocity
tunnel contraction.
sentation
of
the
data.
It
Ue is
is
used as the
assumed
that
of
Ue
-
33.5 m/s
reference
monitored at the end
velocity throughout
Ue remains constanz
along the
-he
shear
prelayer
*e
This flow was added by the Organizing Committee after the Edited by S. J. Kline. 1980 meeting in order to provide cases comparing symmetric and asymmetric initial contains measurements of third-order correlations as a conditions and because it check for turbulence models. 346
o.
.
it
(i.e.,
is
blockages,
taken
due
as
to
the velocity
tunnel
walls,
the boundary
outside
model,
boundary
layer
layer,
and
and
Thus,
the wake).
wake,
and
taper
of
the
plate are neglected. .
Two-Dimensionality Checks
for
two--dimensionality
most downstream .
within
1
1260)
" "
x/6
at
within
edge
trailing The
profiles
Also,
Note span/2
width/26o)
that
the
6
iq
)
is
of
checks
effective of
8.5.
the
gence or divergence at Also,
the
"all
locations shear
values with
ratio of
of
from
the
5
are
span
(i.e., at
of
and the
x/6 ±
considered
200
expeziments
over
8.56.)
mm
value at
part of
the ade-
the wake
ratio
(tunnel
nominally
in
at
(i.e.,
marginally
aspect
flow
9.35 agreed
-
0
centerline
considered marginal since it
(i.e.,
over
at
geometric
0)
-
0
two-dimensional
two-dimensional
the
experience
the
(x/6
plate
stress
5% of
the
ard
the
tunnel width
spanwise
the
aspect
this is
edge
70% of
two-dimensionality
spanwise
contamination
(or
some
other
from 70% of tunnel width (a. TE)
of only 4.25 wake widths.
cult to justify
trailing
two-
invites flow conver-
the centerline due to the growth of the untreated corner bound-
the
gion of two-dimensionality distance
two
Cf
order
Drawing
dimensional boundary layers,
ary layers.
for
over
50% of
for
gave
the
Pitot traverses indicated
at
charts
at
profiles
over u
centerline
These
0
and
Clauser
from the edge.
(i.e.,
. 9.35).
0
the
± 3.746o)
quate.
were made
mean velocity
4%.
trailing
6
(x/
to 2% of the
9.35.
-
0
station
This would
suggest
-wo-dimensionality of the flo'
reduces
to 50% (at x -
that
beyond
factor)
it
the re-
9.560)
in
a
would have been diffi-
the last measuring station.
Free-Stream Conditions This should
experiment
corresponds
remain constant
ted.
Andreopoulos
which
was
edge"
on
due p.
to
159,
an
idealized
along the stream.
However,
(1978) the
information was reported If stant
along It
Figure
the
has
4.4 on
shear
been p.
constant
two-dimensional,
the
is
acccpted,
layer,
found
by
the
flow
in
which
the
existence
of
thickness
of
the
values
Cf
in
the
that
momentum
the
values (1978) at
Ar.dreopoulos
in
the wake
and
the influence
and
of
within
±
is
"the
small
flat the
assumed
thickness of
6/60
are in
the 2X
it
error.
at
asymmetric
should
the wake,
.
gradient trailing but
no
involved.
the
pressure
remain on p.
constant
is
con-
in
the
44 and plotted
in
The integral parameters have request.
therefore
of streamwise
pressure
pressure
plate
that
tabulated
reviewer's and
static
no pressure raeasure-ents are repor-
on the magnitude of the pressure gradients
64 of Andreopoulos
re-evaluated
remains
reduced
discussing
two-dimensionality
wake.
been
acknowledges
gradually
while
to
the
These
flow may
pressure gradient
be
show
that
6
regarded
as
may be neglected
in
-he wake.
I[Ed.:
The corrected values have been put on the tape
file;
see File
1 of
this case.]
347
p'..
With
of
the presence
a
indicates
shown
is considerably
higher
boundary
and
the
of
2.6
has
layer
bnundary
a
This
flat-plnte in
developed
an
parameter
pressure-gradient
equilibrium
a
0.75
The existence of an adverse pressure gradient is
0.49.
(1968)
Wieghardt-Stanford
IDENT
R6 -
at
present experiment
x - 0
lowe: value of Cf and the higher value of H at
the
by
-
+05
2nf.l
in other flac-plate boundary-layer experiments (e.g.,
those observed
3.0).
is to
attributed
usually
(1978)
Andreopoulos
estimate
evaluator's
upstream
the
of
0 (the
x -
profile at
can be eatimated using the correlation*
0.418, we have further confirmed
(the
acknowledgeR
experimenter
4.3
Figure
of
3.8
equivalent
An
AU
-With
plot
value
that
suggests
(6*/U*)(dp/dx)
.
of
the
plate,
The mean velocity
gradient.
(AU/U,)
than
the
on
logarithmic
gradient.
pressure
adverse
the
in
component
wake
layer,
layer
boundary
the
small pressure
a
edge)
trailing
to
regard
-
1420
13,600
Cf
yields
-
H -
- 0.00247,
Cf
gives
than
13,040,
for R,
-
1.334,
while
the
1.389).
0.0023
and
H -
probes
were
used,
Mean Velocity Profiles
to make
manometers,
mean
The
within
probes
pitot
l-mm-dia
recorded
The pitot and static
5%.
profiles
velocity
evaluation
accurate
Andreopoulos
with
wires
hot
profiles
are
shown
agreed
with
the
contain
the
of
sufficient
a
pitot-static
data
points
to
results
enable values
earlier,
noted
As
parameters.
integral
of
number
are incorrect and should be replaced
(1978)
in
Betz
4.1-4.3.
Figures
relative to the wake width,
small enough,
probes were
with
together
effects to be considered negligible.
for probe-displacement The
The
measurements.
these
velocities
static
and 2-mr-dia
an in
by those given by the evalu-
ator; see data tape.
-
profiles
velocity
The
appear
to
symmetric
be
about
the
wak'
centerline.
graphs show U/Ue going to 1.0 at both edges of the wake at all 10 stations. is
the constant reference
Stresses (u.
this
suggests that the free-stream velocity,
22-
v
a
MEASURED.
NOT
where
stations x/6
0
- 0,
The
0.935, data
E.
Coles'
The
turbulence
mean
velocity
1.869,
shown in
by processing
(i.e.,
D.
the
measuring profiles
stations
were
do
not
measured.
all
The
Note that w2 with
the
stations
are
coih~cide common
and 3.738. Figures 4.5-4.23 of Andreopoulos
recorded signals after
A + D
(1978)
conversion)
were obtained digitally from x-ire
the form given by White (1974).
wall-wake correlation in
348
.............
and
-v)
These were measured with linearized DISA hot wires at 6 stations. WAS
Since Ue
remained constant along the wake.
therefore the pressure, Reynolds
velocity,
The
,
.*
traverses.
C.n u7-
obtained
from
experimental
analog
scatter of
equipment
5%
(see
agreed with
p.
49).
This
the
digital values
appears
reAsonable
with
a
maximum
with regard
to hot-
wire measurements of Reynolds stresses and may be used as the confidence level. There However,
is
centerline region
no way
to assess
the profiles of u while
those of uv
of flow development
ted that the symmetry, Andreopoulos those -
of
others
normal
and
KlebanofC
son.
and
are,
as exptcted,
[r sent
to establish
shear
of the hot-wire
measurements directly. symmetric about the wake
antisymmetric.
established at the trailing edge,
not
evaluator has undertaken
accuracy
are reasonably (within 5%)
Since the streawwise
is roughly 8 Limes the shear-layer thickness,
onc,
does
the
and 7
any comparison
credibility,
this task
str. 3ses
is
expec-
his
turbulence
data
and
some could have been made.
The
Figure I shows conver.dional plots of the Reynolds
measured
similar meacurements
between
although
it
would persist.
at in
t.-!
trailing
edge.
The
two other experiments
are
flat-plate
included
data
of
for compari-
U* and 6 values quoted b) the experimenters are used. It
is
seen that Andreopoulos'
shear-stress measurements are somewhat hiier
those of Klebanoff and imply a small lo'al adverse pressure gradient. clusion could also be draw-.
from the measured u'
although
v'
is
in
than
A similar conreasonable ag-ee-
went with| Kiebanoff's data. The
Reynolds
(x = 400 mm) Kovasznay proper
stresses
have also
(1960)
u-,
v'-,
and by Ramaprian,
scaling
laws
for near-wakes
preted with udution.
Nevertheless,
distances
6 0
(x/
and uv
been compared
= 8)
measured at
with
Patel
the most downstream
similar measurements
and Sastry
are not known,
(1979)
(see
station
made by Chevray Fig.
such comparisons
2).
and
Since the
should be inter-
examination of the data at similar non-diwensional
from the trailing
edge shows that all three sets of data are in
reasonable agreement except that the values of Andreopoulos are somewl mt larger in the outer parts of the wake.
This is perhaps due to the differences in the initial condi-
tions at the trailing edge. u3
Triple Products
2
(u
uv _,
u v,
and v.)
These are shown in Figures 4.24-4.47 of Andreopoulos w were not measured.
It
since a standard
comparison
College
group
for
has
stresses.
do
not One
to establish the reliability of the data not available. Nevertheiess since the Imperial
is
experience
with hot-wire
the
same
level
measure of the accuracy
of
symwetry
of the data is
data from the expected symmetry or asymmetry.
"
-'
" "
"
" -"."
•.
= =
.
-
.
.
.
or
these
results
The profiles of triple
asymmetry
as
the
Reynolds
therefore the departure of the
Zxamination of the data on this basis
349
*1- "
anemometry,
the state of the art in dcta acquisition.
exhibit
Products involv4 ng
again difficult
had extensive
appear to represent products
is
(1978).
.
,
L
suggests
a
believe,
could
the
of
scatter be
used
a
rough
the
trailing
as
the
20% of
of
order
guide
measure-
triple-velocity-product
mo6t
for
I
Thjn,
values9.
maximum
respective
ments. The
measurements
reviewer
some
with
previous
edge
measurements
in
(Y
-
0)
have
the
boundary
also
by
th,'
by Bradehaw
and
been compared
layera
made
These again agreed within the 20% bracket mentioned above.
his students.
K
ASYMNETRIC WAKE BEHIND PLATE WITH ONE SIDE ROUGH
CASE 0382.
e:-periment
This
was conducted
the same facilit
in
the symmetric wake expert-
as
on one side to gene-
smooth plate used for the symmetric wake was roughened
The
ment.
at
The measurements consist of the following:
rate an asymmetric wake. (a)
Mean velocity
Reynolds
stresses u
v-1,
mm.
x
Triple correlations
(a)
Intermittency. Conditional
-
0, 25,
50,
100,
-
0, 25,
100,
and 400
v3
ul, u v,
averages
x
uv at 4 btations:
S2,
(c)
(e)
stations:
at 6 streAmWine
and 400 mm.
200, (b)
profiles
to
uv
study
and
at the 4 stations in
the mixing
in
the
central
(b).
part
of
the
wake.
.
Thib evaluation is mation in
the
connection -
will
be
test
with
and
facility symmetric
the
discussed.
and is
based on the infor-
(1978).
Andreopoulos
Since
four items (a-d)
restricted to the first
The
experimental
case,
only
on
comments
the
the
were
procedures
between
differences
accuracy
of
reviewed
the
the
in
detail
in
two
data
sets
in
Case
0381
measureme-ts
apply to this case also. Test Facility One height
side
of
the
of
I mm,
flat-piate
giving
wodel
was
thickness of
a trailling-edge
by
roughened
sand paper
1 mm
(in
with
a roughneas
place of the
0.07 mm in
the symmetric smooth-plate case). Two-Dimensionality Tests
made
Andreopoulos, Audreopoulos *
case.
The
for
1978)
two-dimensionality for
indicates writer
the
that
affected by Lh, small change in
the
the
case.
-symmetric
that such tests
believes
in
symmetric However,
case
are
a private
gave results similar two-dimensionality
to
or
not
communication
those in
lac& of
it
(in
reported
from
the symmetric would
not
be
geometry.
[ed.: See also report of Ad-Hoc meeting on expected uncertainty in
(Newman) Committee hot-wire data.]
in
the
Proceedings
350
-
.-
-- Z
-a
of
the
1980
Free-Stream As
"small
side,
(6U/U,)
Implying
(-
.ear,
entirely
3.2)
a
edge"
plot
is
smaller but
vwiiTh was in
gradient
the logarithmic
smooth side
ment,
gradient
pressure
made.
Although
the experimenter
due to the gradually reduced thickness of
connection with the determination of Cf on the
can
only
of Figure
be
estimated
from
5.11 of Andreopoulos
st'aller
than that
observed
effective
pressure
gradient.
correlates
it
were not
meAsurements
the trailing
the
on
presaurp
pressure
flat plate at
rough
the
Cane 0381,
in
mentions the
Conditions
the
with
larger
(3.8)
The
defect
defect on
the symmetric
reasce
of
value
velocity
(1978).
in
The
the
for
Cf
experi-
this
(0.0024
is
not of
instead
0.0023). Ac
in
the
symmetric
case,
the
re-evaluated
momentum
thickness
remains
constant
within 2%. Mca,
Velocitty e
Profiles
profiles
Andreopoulos srae
measured
(1978).
continue
The
to apply,
by piltot-static commtnts
probes
on accuracy
are presented
made
in
in
Figures
connection with
5.1-5.6
of
the symmetric
except of course symmetry can no longer be used as a check for
flow quality. Reynolds Stresses These the
_u uv)
estimate of
techniques
surface
symmetric
wake
reliability It
chould
These
fact
are
two
and
be
0332)
noted
Reynolds asymmetric
shows
that
Cu
and
influenced
by
5.25 of Andreopoulos the
(1978).
symmetric case,
Since
the previous
stresses wake
at
the trailing edge measured on
(Case
excellent
0381)
agreement,
and and
those
is
an
measured
indication
the
in
the
of
the
the measurements.
the value
of
Cf at
tne
trailing
edge
on the
rough side
5.45 of Andreopoulos
(1978).
The accui-
the measured uv.
v
plotted
sets
of
rough)
sampling),
9idered
the
in
i'Igures 5.30 through
these measurements
that
(smooth
(Case
the
by extrapolation of
Products
racy of
in
through
assumed to be reasonable.
between
side
5.14
the same as those in
and repeatability of
was assigned Triple
were
5% accuracy is
A compariso.i smooth
Figures
data are shown in
measurement
appear to
data
were
the
arr,
small
in
good
amount
same as those in
collected at
sutface boundary
they
be the
of
each
station,
the symmetric with
layers heated at different
overall hent
agreement,
addition
suggests
(i.e.,
data.
the lower
times (for that
the
buoyancy effects
Th.e
and upper
condiLienal flow was
not
can be con-
negligible).
351
S-
.
-2~~
2
A...
.
"
'
~*
.. -
,.-'.. *.-
.
-.
,
.
--
NOTE ON DATA PRESENTATION As
indicated
in
the
preliminary data-evaluation
(1978)
tiow provided
the tabulated
data.
recommended that the tabulated data be used in
It
tape
is
contain
several
errors
and
report,
Andreopoulos
integral parameters,
the results
inconsisteucies. mean-velocity
J.
presented
Andreopoulos
profiles,
in has
and turbulence
further analysis;
see data
for this case.
ADVICES FOR FUTURE DATA TAKERS If to
be
simple used
as
two-dimensional
wake
test
modern
from the boundary important is
layer
for
somewhere
as
those
calculation
reported
methods,
on the body and
by
Andreopoulos
calculations
should
continue into the wake
realistically.
as inputs,
Starting
circumvents
The ideal test
the
solutions
this important
in
the
wake,
are
start
so that the odge
problem of the discontinuity In the boundary conditions at the trailing
addressed
files
cases
flows such
with measured
pro-
flow problem.
case should poscz"s the following features:
(i)
well-documented data in
(ii)
sufficiently the wake,
detailed
including
the upstream boundary layer; data over a
at
least
reasonable
downstream distance
the mean velocity
and
in
Reynolds-stress
profiles;
two-dimensionality,
(iii)
or documented measure of three-dimensionality.
From the discussion of Andreopoulos' count,
namely
geometry
is
insufficient
simple,
conditions.
In
it
both
pressure gradient
information
should cases,
be
data it on
the
possible
this
would
to
is
upstream "invent"
require
due to the taper on the plate,
necessary to determine an equivalent
clear that they fail only on one
the
boundary
layer.
reasonable
upstream
prescription
and in
Since
of
starting
"effective"
an
the asymmetric
the
case it
may be
roughness height.
REFERENCES AFOSR-IFP-Stanford Vol. II, D. E.
Andreopoulos, Thesis, White,
F
J.
Dept.
1968 Conference on Computation Coles and E. Hirst, eds.
(1978).
Turbulent
"Symmetric and asymmetric nea" wak.!
of Aero Engr.,
M. (1974).
ot
Imperial College,
Boundary
Layers,
of a flat plate," Ph.D.
London.
Viscous Fluid Flow, McGrpw-Hill Book Co.,
New York
7041.
.
.
1:
352
" "-"
- - -
.-.
~
.
.
.
.
-
-....
.."**.
-
;.
- - -•.i--2.
-
."- "
2.4 -
______
* 12
MI
-
2.0 0."x
_---="'
(U 20
7
(uT) I/-
/|1/U.
flat plata
Kebe~off.
Andreopouloa,
ay..
Androopoulos,
revised,
Che.ray & U, t.-C
0
x x
v ry, 0.046
-
0
-0.2
c.,".
L
0
*0
0 0.3
0.4 -
2
S0-• 0o
I
0
0.2
":
A:••'"o. _
0
0.4
I 0.4
1.0
0.8
0.6
-;.
y/8 Reynolds normal stresses of various observers.
Figure la.
_____
U
KI.
0
V
N
plate
flat
sYs.,
U•
Andreopoulos,.
revlse,
x
Chavray & Kzvaaz,.ay,
S0
0
-
x - 0 x
*
0
..a.
ja coaa,a . -7-.
-.
0.4-
bsuoff,
Aadrtopoulos.
L
1.0
2
0
0.2-
01
o Figure
0.2
lb.
0.4
0.6
y/8
0.8
,.0
1.1
Reynolds shear stresses of various observers.
353
i1 1.0
•aI
0
Chavrsy
4 Kovanbay,
x/4. o 10.2
0
Chavray
4 Kovoest
x/do - 30.6
'
lo..
A
Andrsopoo.,o,
data.
y,
./60
1o7.4
-
.
ON* (00/
A
04x
2
20
-0.6faaz
•
0.4-
*
A
0.2-
. 0I
0
0.4
0.8
1.2
1.6
2.0
2.4
y/bUi2
Figure 2a.
Reynolds normal streas at most downstream stations of various observers.
o
Chevray 6
0
Chtvray & Ko-ae.n.y,
X
lOea
1.0& 1p 0
0
data.
.ovaos
0/10
Andreopoulo.,
ay, x/6, .160
- 30.6
. 17.4
X,!.
*
7.5
0 *
A
1L/20
(v)aax
0.6-
0.4O.Of 00
0 .4LL 0
L I 0.4
0.8
ILI
±
1.2
1.6
y/b1i
Figure 2b.
I
I 2.0
I
I
I
2.4
12
Reynolds normal stress at most downstream stations of various observers.
354
ii
Chevray & IKovassraY,
1.0
/60
& Kovtlznay.
Chevray
x
M
./6o°
0. 2-"
30.6
S•
X
Ilow& fita, j/60 - 17.4
0.8-
8 A AploA7.5
0.6(7v) /•v=Uý
•,x
0.2
"
0
1 0
Figure 2c.
0.4
1
1 0.8
1
1..L
I
1
1.2
1.6
0
".
A."
1 %1 1.8
1 2.4
Reynolds shear stress at most downstream stations of varicus observers.
.- S. ,
'4l
355
Ii
::~--::,
2
355
-
ii.;
.
-
•
•.".".,
'
SPECIFICATIONS FOR COMPUTATION
ENTRY CASE/INCOMPRLESSIBLEA
le,-!
V. C. Patel
Data Evaluator:
Case #0381;
Data Taker: L7 J. Andreopoulos .
FICTUIJL.L BSIN0" FLOW0380.
Data
Iee
V- C- PG%01 *IIkes at ?~Tlt..ele~La at~ of
Test Rig DaaOt aetyCV
Case
J.r..
~
or
or
proile
2=
VI
I
1here
Abscissa
ordinate 1
~
C1
rate; CLOG.
J."rsolsA
Plot
teld
I
_
0cor-
O
~
dt~i.*
...Neored ":e
tse
T-.1
-11"1
I
to
0 <
UV/Ue
-50(
~
< 100 mm
~
other votes
Strom Coadit I " I 2.feges to to 0 st.dy the eI0I1-! t- tbe (based tuth. 0.052 r.,irel part of .06.. oo L)
4
1
Comments
Range/Position BE Se cial CAEInsrcOtPons:
~~~y U/Ue y~ ~
Ce ties
5profiles atx 0,51, x5 , 10 0 10 mm.oilst
~
I-.
2y
3 profiles at 400 mim.
x250, 100,
-1
3
y
6
y
uvLeU
v2/
2
1.
o0-
iita
2sCalculations
evU
-50 < y < 50 mm
3 profiles at. x -25, 100, 400 mm.
- 50O
3 profiles at 400 mm.
x.-25, 100,
.
11.69 mm. should
begin
just
upstream
of
the
trailing
edge
(x/00
prefE~rably continued to x/60 se1200 to check limiting asymptotic form.
356
0) and
T
I
0I
PLOT 1 CASE 0381 FILES 12,14,15,22,27
O10
0
0
0~
01 '
0
0
00
.i
0°
e t
0
o;o
L
0~
0o
_
io"1
50o
"0
10
00100.,j0
U/u, PLOT 2 CASE 0381 FILES 6,7,8 lo 0
S so x
0
0
50
-
00
1
0
0-,.::
0
-4
__
10
01
10o
0
0*-
o
00
000
0
S00 I4
0
±
-50-'
0
2
0
o-2
"
,
-2
- ::.'I
2
.
-2 .. ,
,
,
'......
.
.
.
.
.
..
......
.
.
,P:;
357
.
...
35 .
-
i ,J
PLOT 3 CASE 0381 FILES 6,7,8 2500
400
50F 50
0
t
0- 0
00
0
0
0
Y0
0"
0 0
°2 0
0-0
00
0
0
0. 5
0
0. 25
0.5
Iu
o""-
0
,0
0-25
.
0
00
0
0.25-
0.5
.,-
u 2/U2
PLOT 4 CASE 0381 FILES 6,7,8 0
100
25 o
1
0
~L
00
0
0
° 1"00
0
000
0
0
0
I
01.-
00
20
0
.
22
v /u
358
,
IE
38
PLT4C•
0
e
0
i
I...
PLOT 5 CASE 0381 FILES 6,7,8
"
I
o
1
O00
o
x -25 •, 2 5o
0
0
[o i
o
o 0
00 50
4
0
0
0
0
o
[
:
~
4 00-'-
000
0
0
0,
0
0
t o°
0.25
0
00.5
_
_
_
0.25
0
0.5
_
_
0.5
0*0
••
e
-:
PLOT 6 CASE 0381 FILES 6,7,8 x-25i
0 0
50
-
1m
100
4I
0
*
5
0.5
0
{. 0
50t01 50
0
4-
.
.
0 I
o~O
0.5
02
.
I:0C00..
L.4:.b
0
0
0.25
:
0
0_
S0
-
O0
*
02
0
,
C
T
01
- 50-
,.)
-
0
1"-
io o
I
00
0
0.25
I
0.+
0
0.25
0.5
•
e
359
ELL
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case 10382;
Data Evaluator:
Data Taker:
71.. 02.4.
Data 2
J1.Andreopoulos
V. C. Patel.
Ita.lorr
V. C. Patel
*Vak..
of N-Minar..1.al
C*114 kia
Test Rioo Goe"iry
~ ~
C9
U
a
1
Others
i
Come0242
Triple car-
Plot
____________
__
Ordinate
Abscissa
Range/Position
y
U/lie
0 < y <100 mm
*1
y
4
y
ainitial
-15.4
( 0.051
costralport of wake.
.
Comments
3 profiles at
x
-25,
100,
U e
-50 < y <50 min
3 profilea at 400 mm.
x
=25,
100,
v 2 /UZ
-50 < y < 50 nm
3 profiles at 400 mm.
x
-25,
100,
v2 U
-50 < y <50 mm
3 profiles at 400 mm.
x
-25,
100,
-50 (y
3 profiles at 400 mm.
x
-25,
100,
550
50 mm
Special Instructions: 00
an )
mm
I 1.
rak. &.yam rit lCo. C dtri.a tataI Coo .
-0,
u 2 V/U3
6y
4.6 Fr.06U a,.
x
2
5e
C"~I-i.
.
4 profiles at 400 mim.
7,U
3
C1
........ 1......t~..L t fod.
___________-
6"16..
Moisorei
Meber ofStotiop
mm.
360
25,
100,
PLOT 1 CASE
0382 FILES 40,42,45,49
I00w
' 0'"0•
I
°iI SI
:
o
I;
0'01
0l
t
o:
0
0
°1000~
N50 r
0!
0
I
0
-4
0 01
00
0
0 0
0/
I
I
*'
1
1:
10
0
"o
50
0
0o
0
0
00
Ti
0
01
°
1
:
0
tO
-'0
-
PLOT 2 CASE 0382 FILES 9,10,11 5x[
0
0
1
50
0
00
0
0
0
0 C
0
0
0
0
0
0 I
0
0~o
0
0
;
0
00
0
-Y0 '-
-2
T
0
ip
0
0
'
000 400
0
2-2
0
361
2 -2
0
2
•"",-
PLOT 3 CASE 0382 FILES 9,10.11 -~----7-7T
--
X'
0
50
0,r
+
1
25
0 00
100
|
400
0
0
0
y
0
0
000 DC
,
±
o0 00
0
090
C
o°
0
-50-
"0
0.5
0
1
0.5
0
1
0.5
PLOT 4 CASE 0382 FILES 9,10,11 .,
-
,
0
0 25
x
0
-
100
40
0
0
00
0
00
00
4 00
SI 00
o'
0
-
o
•"5
0
C,
o
00 00
.1
='41
• 0
0
0 5 0
0
2
0 .
° ,..
0
2
0
w/e
.
362
.
.
2
PLOT 5 CASE 0382 FILES 9,10,11 0 0
0 o00.
"0 50
100'"
V
x -00
400
0
1 oI
[0
1000 0-
00 0
1
0 00
0
00 00
I
0 -30 0 x2So
50 --
0 oo
.
1
0 o
|
T
0
-
"0
0
00
j20510j01 ]3
00
0
I
-"
- -o
-
/.
- -_
- - -50-
.
- 2s
--
o ..
"
--
~.
c0
" 0.
1
1
0
.
0
o.
--
ooo
.
0,
.4o
--
1A
1
J
EFFECTS ON
COMPRESSIBILITY
-. LEE-SHEAR LAYERS
Flow 8500 Case 8501 Evaluator:
P.
Bradshaw
SUMMARY
SELECTION CRITERIA AND FLOWS SELECTED It
appears
fectively Eggers
plane
regarded as
36)
in
Of
the
nesses downstream of
the
number are
in
and Lau's
< 1.5
in
full
even then
it
"nearly
fully
developed."
the Mach 19 data were taken only a the
'Langley"
curve,
with that
M e 1.7
only;
Mach while
19 data
thick-
rather
wide
at lower Mach
the measurements Armstrong's
curve.
few boundary-
provide a
is
flow (1976)
sub-
the behavior of the spreading rate for
the sensitivity of
free-shear
layers
to
initial
was fairly clear that some of the supersonic-mixing-layer
rate
consensus
curve
o).
as being does
well
known,
free-shear by
high Mach
no significant
extra
that
of
M
and boundary but
data were onom-
test
the
layer
is
case
effect is
number data
or anomalous
disturbed
flow,
but
the
to
much
smaller
zhat
the
of
obscure,
while the effcct of density
trend
of
For the
asymptotic
than
the
if
Again,
by Birch and spreading
of a
density difference
were
spreading
there Eggers
scom to have been (1972).
rate with density
present purposes
change it
is
London,
SW7 2BY,
proposed
Engiand
364
..
. .
.
.
-
-
_
The
.'-..'.
zon-
ratio is
of spreading
*
Prince Consort Road,
spreading
rate
on the
ratio on tht' percentage
with the velocity ratio was small.
the
(i.e.,
0310).
fluid.
a homogeneous
since those reviewed
review were
represent
differences
of denetty
very in
intended
test case (Flow
clusa'.Ws
Imperial College,
"Langley"
seem to reject the data with higher spreading rates
the low-speed
x + -, as in is
result
the
indeed
present
The
rate for
produced
be
and Wagner
largely conjectural.
horrors of
spreading
low-speed
to
(1975),
's probably too facile to denounce any measurement with a higher-than-usual
It
As
to be that listed in
only to about sixty boundary-layer
Therefore,
'xit.
f-w
stated
be
cen still
have only been realized since the work reported at the Langley meeting,
conditions
alous.
(1Q80)
Plot 4 is
The
extenc•ed
reasonable agreement
sonic,
are
results
given by Birch and
proceedings
meeting
Harvey and Hunter
(1975),
for plane or ef-
number
layers" or "half-jets")
free-shcar-layer
wl.ile
for the
Mach
the only subsequent work appears
5
the exit,
of extrapolation
choice
lov'er
Mach
against
rate
("mixing
M - 2.46
from
thicknesscs
layer
layers
Ikawa and Kubota
mebsuremetits at
!kawa's
spreading
Indeed,
(1976),
these,
of
the Langley
definitive.
Armstrong et al. (1973).
plot
free-shcar
p.
(1972,
the
that
rate
to accept
the
latter
conclusion,
tion of ,nd
with
o
the
Roshko state
at
P2.,
-
relying on the measurements
racio of
secondary-bLream
to
of Brown and Roshko
primary-stream density
that the inverse of the relative
7
and
to 0.74
Mach numher,
the effect
ahle-eenstty
and
at
p 2 /pl
of density is
compressible
1/7.
-
Compared
small.
cases,
It
spreading rate with
p 2 /pl.
therefore
the variation
not
be
Brown
is equal to 1.33
0o/a
of o vith
For purposes of distinguishing
should
1
for the varia-
the vari-
necessary
to
enter
into detailed arguments about acruracy of tho Brown and Roshko measurements. The
mixing-layer
prevsibilIty umoreon
•iJethat
-
effects
the
veiocltv
on
are
probably
turbulent Mach
fluctuating
the most suitable
flow,
because
number than
on
those
Mach
number
quantity
under
the
boundary
layer
it
fluctuation
sqaare is
of
compressibility
effects
layers
significant
and
are
Mof
m/
sign is
of
order
(Cf/2),
say
root order
appear
at
at
IF
speeds
raal gas effects,
well
etc.,
e
/TF7-, In
Taking a
the
depend typical
mixing
layer, while
0.002 at mixing
those
to
low Mach number,
.
at
likely
com-
for simplicity we find
in
below
are
number.
to
Me
testing models of
effects
U2I e
0.01
0.001
lower
much
for
the mean Mach
fluctuation as V(max kinematic shear stress),
the
uincertainties, -
data
low Mach layers
at which
the in
number.
than
in
serious
'1
a"
Thus
-
boundary
m2asurement
begin to affect boundary-layer data.
ADVICE FOR FUTURE DATA TAKERS It
is
scale
and
layer
well
easy total
particularly with
Mach
Birch's -
*
writer
Sonly,
that
least
It
demand
pressure
that to
experimenters
ensure
full
before
the
end
since
the
length required
number
as
cvaluation
Thig
keep
to
the
report
recommends the
nozzle
of
the
Cest
spreading on
that if bounda.y
section;
layer
it
is
should
However,
large
development is
The apply
to investigate be
a
less
easy
self-preservation
decreases.
thin and partly because full development for single-stream mixing layers.
but
mixing layers
the object
choose
self-preserving
to achieve
rate
row-speed
should
kept seems a
enough of to
the
achieve
in
even greater
the self-preserving
laminar,
if
mixing
possible,
S.
case
1."
fi,,ws
partly
for calculations
F.
force.
to be achieved more rapidly,
test
It,
probably increases
recommendations with
spatial
to ati
begin-
ning at •ireport meat
the exit is better conditioned if the initial boundary layer Is turbulent (see of Ad-Hoc Ccmmittee No. 3, Session XTIl). I'e problem of mtxing-loypr devclopfor various initial conditions deserves study at any Macio number. Mean velocity
measurements pictures
should
always
be
accompanied
by short-oxposure
Schlleren
or shadowgraph
to ahow up the eddy structure.
6.5
365
'•
i
|~'1";
REFERENCES
ofroa
Armstrong,
R. R.,
number
on
fluctuations
Noise Control Conference,
"Influence of Mach
and U. Michel (1976).
H. V. Fuchs, A. Michalke,
pressure
relevant
to
jet
noise,"
presented
"Free turbulent shear flows," NASA SP-321,
Birch and Eggers (1972).
at
the
1976
Warsaw. Vol.
1.
"Experimental study of a free turbulent Harvey, W. D., and W. W. Hunter, Jr. (1975). shear flow at Mach 19 with electron-beam and conventional probes." NASA TN D-7981. Ikawa, H., and T. Kubota (1975). with zero pressure gradient," Lau,
"Mach ntuier and temperature Fl'zid Met:]., 93, 1 (1079).
J. C. (1980). See also J. 609.
Wagner,
"Investigation of supersonic turbulent mixing layer AIAA Jou., 13, 566.
"•iean
R. D. (1973).
jets," AIAA Jou.,
on
effects
flow and turbulence measurements
18,
in a Mach 5 free shear.
See also E. L. Morrisette, S. F. Birch, and K. D. Wagner layer," NASA TN D-7366. (1973). "Mean flow and turbulence measurements in a Mach 5 shear layer," Fluid Mechanics of Mixing, E. M. Uram and V. W. Goldschmidt, eds. (1973), p. 79, ASME, New York.
DISCUSSION Flow 8500
SThe
committee computations it
is
agreed with P.
Bradshaw's
suggestions
that:
must be performed from
"G.Settles' curve,
by G.
mentioned
compressible
up by the
flow.
committee.
The
h - 3,
Also,
some
(2)
the calcul'tions
Saffman and Oh
which falls on Bradshaw's
committee observed
Horstman has successfully computed
Settles,
in
through the range of Mach numbers.
remark about a new set of data at
brought
was
M- 0
since
U2 - 0, it is acceptable to
not possible to solve for a flow with
extrapolate V2 to zero from two or more cases with low U2 values; -
(1)
the
fact
the spreading
(as mentioned by D. Bushuell)
that,
as
rate in a
have carried
out similar calculations. The committee questioned the validity of the postulate for high ratio of dinsity for the low Mach number case of the problem.
They stated that the specifications o-
the problem for this case are not clear. During the discussion~s after the presentation, lations
be
carried out
for unequal
stagnation
Dr.
Saffman suggesLed that CnIcu-
temperaturces.
Also, A.
Roshko ques-
tioned the validity of calculations of opreading rate at low-speed flows (low M).
366
SPECIFICATIONS FOR COMPUTATION SYMPLE CASE/COMPRESSIBLE Case 38501;
Data Evaluator:
Data Takeis:
P. Bradshaw
Various
FtCTO4IALItM0HEY Flow IWO0. "~to 1avoluAter P. Bredob...
*A~ressibk.
fPo thea * Sb...
Wate s
rs..
1
kinbat of &tatta..b.....r*d Velocity
l.rh.ls..c
Profiles lei-
Toot ha Ciemotry
Case Data Tokwr
o C
1,
ciee
1
6/x
Wv Or
vs.
K lives.
I.
..
Ob
46/4t
't
Abscissa
Range/Position
M
0 < M < 19
or
Nt
a. M..ch aber.
"S"tbd C..te
Ordinate
.1
I
Coadi i.
olrae.
Part.., date taksto
Plot
or V
Comments
L
Classical spreading rate vs Mach number distribution.
0.02 < d6/dx < 0.15
c(l)
Special Instructions: *
Definition of Specia. Symbols: 6
of
/x is tabulated irtthe file.
the
linear,
asymptotic
The equivalence of 6/x and d6/dx implies the use
relation
between
6 and x using an appropri~te
value of
starting length x0. 6 vamixing-layer thickneas between U/Ue ss/0.
and
ý1.
The test ct~ae is to reproduce tne curve of P:-sading rat~e presented in the pro*ceedings
of the "Langley" meeting (see NASA SP-321). simple mixing layers in nominally still air.
*
the ambient air were nominally the same.
*
speed mixing
layers
(Flow 0310),
All flIowa were nominally plane,
The total temperature of the stream and
For uniformity with the test cases for low-
the data
correlation presented
in SP-321 has been
converted into a graph of d6/dx vs M, where 6 is the distance betwcen points on the
V'0T
velocity profile at which the velocity is maximum. *values
have
*(G.1.15), *
We have taken been
modified
see Flow 0310. 7981
(1975)
d6ldx se 1.3/o
the
consensus value
The range of values of d6/dx at
M as 5
by
and
two points at M
-
and
10T9 E 0.949 times the
for an error-function profile.
to agree with
has been bracketed
interpolation between
0.316
19
M
-19
of
M se 0
d6/dx at
data from NASA TN D-
that Mach number
is offered.
The "Langley"
on the curve;
With the exception of
M
-
the points on Plot 1 are derived from the curve in SP-321 and are not data points. 367
no 19,
effect
initial conditions
of
to
required
are
computors
Since
values
asymptoLic
produce
the choice of
has died away,
d6/dx
after
the
starting profiles can be is
The error-function velocity profile
left to the computor.
of
for starting,
adequate
bit the origin of the error function (the half-velocity point) depends on the density profile which is
0.71
at
requires the origin of the lead6ing to
n - 0.043
U/Ue
n - 0); for practical profiles this is an overestimate.
at
to a secondary stream
The data refer
"*
(i.e., U/Ue ' 0.5
n - 0.043
to be at
error function
fU 2 dy
At low M, constancy of
uncertain.
speed w lich is
air should per-
whose programs will not run satisfactorily tor mixing layers in still secondary stream speeds,
ialues of
form at least two runs with small
Computors
zero.
nominally
and extrapolate
to zero speed.
as
gradient at
low
lation.
different
densities
in
the
primary
and
results for zero secondary speed may be obtained by extrapo-
streams; again, should be
Runs
with
layers
density
and of
compressibility
their pr:ograms permit--to perform runs
requested--if
mixing
on
number
Mach
secondary
computers arr
.uch,
of
the effects
distinguish between
to
In order
ratios
density
out at
carried
or
7 and
Higher Mach
1/7.
number runs with diff.rent total temperature in the exit flow or ambient air would be of interest but no reliable data ex
t for comparison.
PLOT i CASE 8.01 FILE 2
00
0.10
0
1'
0.05
or (d6/dx)
3"8
_IXK
:
0.05
L
•
o 0
I
0
.
.0
0
CM
I0
0.00 'L N.3
I
1
0
--
10
5
15
20
i'-"368
•
.
..
•
.
. .
-
.
"
.
.
.
•-
. ..
..
.
.
..
..
SUPERSONIC FLOW OVER A FLAT PLATE Flows 8K00 (Insulated Wall)
and 8200
Cases 8101, Evaluators:
(Cooled Wall)
8201
MI.W. Rubesin and C. C. Horstnian
SUMMARY
rm
SELECTION CRITERIA AND FLOWS SELECTED Many ertLies
of a compressible
These properties quantities is
periment large
(Hopkins II
of
range
Mach
region
profile
recovery
range
In
0.1.. mean
197].;
theory
(Tw/Taw
data
incompressible
flat
plate
'n supersonic
flow.
by
in
Stanton number.
and
their
aggregate
surface-temperature
Bradshaw,
1977;
Skin
friction
is
the surface
Although
al. ,
each ex-
experiments
these
conditions. et
Hopkins
the
up
represented
2.8 < M < 7.4
the theory overpredicts
= 0.3),
prop-
the
It
1972)
has
cover
been
a
shown
that the van Driest
can be used to correlate both the skin friction an. the inner-
data.
addition,
velocity
layer on a
factor,
scope,
and
about ± 10% over the range temperatures,
or
number
Inouye,
mixing-le.gth
mean
of
measurements
provide
include profiles of the mean velocity and temperature and
limited
of
and
turbulent boundary
skin friction,
of
to
been conducted
have
experiments
and
"law
a Mach
of
number
van
Driest
7.0,
for
II
20% when
has been shown
both
theory
to
At lower surface
data by about
of the wall"
suggested expedient
the theoretically
the
0.2 < Tw/Taw < 1.0.
the skin-friction
incompressible
to
by
insulated
and
to
Tw /Taw fit
the
cooled walls
redefi iing an "equivalent
of
velocity" as U
U* - f
and utilizing wall Te)/(TT -
properties
in
.'p
defining
y+.
w
dU
Finally,
recovery factors r (Taw have been shown to remain close to a value of 0.88 over large ranges of
Te)
Mach number (van Driest,
1956). L
These mean measurements. were obtained had not LDV
and
were
developed, where
Rose,
1975;
the period when most of and the
As hot-wire data-reduction
profiles
of
the
gradients
Acharya
NASA-Ames Research
in
confused by density fluctuations,
pressure
without accompanying turbulence
for the most part,
Hot-wire measurements
yet been developed.
was
walls,
obtained,
data were
were zero,
et al.,
Center,
turbulence
1979;
momentq
rather
than
Dimotahis et
Moffett Field,
CA
al.,
the mean measurements anemometer
laser-Doppler
techniques improved and as the were on
measured
flat-plate 1979).
One
on
wind-tunnel
models
(Johnson
reason
for
.
-. S.i-
this
94035.
369
• 5 -:
--.-- '- ' 3, , ,-:
:'Y-..-
.".
•
.:
5
.
:
. "
"" k.-. .
--
_;
o5
-
"
-
..
5
....
-
'..
,- -
,
was that thicker boundary layers are known tinuous accelerarýon..
*
fie total enthalpy in such boundary layers is
to local velocity in .tht to
"*-
oe--",rs on those on
a parabolic
flat plates.
flat
to reflect their upstream history of con-
plates.
fashion,
rather
than the linear Crocco relationship
Thus these turbulence measurements Accordingly,
known to relate
the primary
test of
nay not be identical
the computational
tech-
niques as applied to flat plates will be comparisons of the computed mean properties with those expected from the van Driest 1I 11 method is
* [Figs.
method.
applied to the KArmAn-Schdnherr
As examples,
when the van Driest
ukin-friction law,
the results
shown in
I and 2 are obtained. .RECOMENnATIONS FOR FUTURE DATA TAKERS Improvements
in
the operation and interpretation of the data from laser-Doppler
and hot-wire anemometers
"ments for ments
.a made.
utilized
attached
possible
The
for
relatively
studies
of
small
fluid
models
associated
mechanics
suggest
the nozzle where
on flat
that
supersonic
measurements
plates.
Such boundary layers
boundary layers
retain a memory
measurements at a single station are not adequate.
tions
are
rate
equations
diffusion compete. necessary
within
in the portion
in
which
the
mechanisms
of
of
their
upstream
history.
The turb,,lence-model production,
dissipation,
to have data at successive
stations so
that
and
between these stations can be measured.
the zero-pressure-gradient
it
the rate of change of the Thus,
measurements have
to be made over a sequence of axial stations covering about 100 boundary-layer in
equa-
To study these processes in a region of zero pressure gradient,
dependent variables
"neoses
wind
the pressure gradient has become zero are not identical to those
These
Thus,
is
with
improve-
boundary layers can be performed with greater spatial resolution when these
boundary layers occur on the wind-tunnel walls.
"of
to consider these instru-
gathering data of turbulence parameters upon which tuirbulence-model
can
tunnels
in recent years makes it
region on the nozzle walls
thick-
to effectively
rep-
resent a flat plate. The
instruments should be applied to measure all the quantities they can.
Mea-
surements of all the components of the Reynolds stress tensor will be most useful in guiding modeling through two-equation modeling to models that account for the lack of equilibrium between mean strain and turbulence stress. The Reynolds stresses Pvw and two-dimensionality of these
puw are
good
layers.
Efforts should be expended
tests of the
"pseudo"
flat-plate boundary
to assess both the Morkovin hypotheses and Favre
mass-weighting in a quantitative manner through the careful comparison of LDV and hotwire measurements. Of
the equations
expressed thuoretical
as a
utilized
length
scale,
foundation.
in
second-order modeling,
frequency
Although
scale,
the scale
equation,
or dissipation rate,
the boundary layers on
be
it
has the weakest
the wall of a wind tunnel
370
.-
-_
.•
-,
" •
.
.
..-
•
.
.-
.
".
_
--
-
.*
.
-
.
,
.. '
-
.-
.
-.
.
..
."
.
.
.
-
.
.
..
have
only
suggests
a
gradually
varying
measurements
measurements,
on
scale,
walls
as
multipoint measurements,
the relacive the
place
to
thickness try
of
two-point
or other measurements
the boundary
layer
correlation-length
directed toward defining
better scale equations in compressible flow. Finally,
some thought
generation of modeling,
should be given to experiments designed to guide
and when the models account for the contribution of the remaining scales. surements
will
scales.
have
to
consider
This will modify
the
phase
data-recording
recording of the raw data in time,
relationship
techniques,
as
for it
at
will
These mea-
least
the
largest
require continuous
with subsequent computer analysis.
meters or correlators will no longer be appropriate. increase
the next
when some of the dynamics of the largest scales are calculated
The use of rmsi
Studies will have to be made to
LDV seeding so that "continuous" data of the largest eddies can be achieved.
Histograms will lose much of their meaning. characteristics
of
hot wires
should
lead
The continuous,
to multi-sensor
high-frequency
experiments
here.
response Again,
multipoint measurements vill be critical. REFERENCES Acharya, M., C. C. Horstman, and M. I. Kussoy (1979). "Reynolds number effects on the turbulence field in compressible boundary layers," AIAA Jou., 17:4, 380-386. Bradshaw, P. 33-54.
(1977).
"Compressible turbulent shear layers," Ann.
Rev.
Fluid Mech.,
9,
Dimotakis, P. E., D. J. Collins, and D. B. Lang (1979). "Measurements in the turbulent boundary layer at constant pressure in subsonic and supersonic flow," Arnold Engineering Development Center, AEDC-TR-79-49. Hopkins, E. J., and M. Inouye (1971). "An evaluation of theories for predicting turbulent skin friction and heat transfer on flat plates at supersonic and hypersonic Mach numbers, AIAA Jou., 9:6, 993-1003. Hopkins, E. J., E. R. Keener, T. E. Polek, H. A. Dwyer (1972). "Hypersonic turbuleut skin-friction and boundary-layer profiles on nonadiabatic flat plates," AIKA Jou., 10:1, 40-48. Johnson, D. A., and W. C. Rose (1975). "Laser velocimeter and hot-wire comparison in a supersonic boundary layer," AIAA Jou., 13, 512-514. Van Driest, E. R. (1956). (October, 1956).
"The problem of aerodynamic
371
heating,"
Aero.
anemometer
Engrg.
Review
S t
1,1-
cfo~~~
akin-friction coefficient
-local
.8-
2.3,x1-
Van Driest 11 applied to Krun-Schbnherr Eq.
CCfO.6
17-
4
•1
-3..
Cf
kL
.3.2
Cf o
-'
KACH NUMBER
Figure 1.
Case 8101, Mach number effect on skin friction. 372
4.
c.,.
%°
DISCUSSION Flows 8100/8200 1.
The Conference accepted Cases 8101. and 8201 as valid test cases.
2.
In response to P. Bradshaw's question about the maximum. frequency of data recording, M. Rubesin responded that with state-of-the-art equipment a frequency of 105
*
.
Hz cn be recorded on FM tape recorders.
374
I SPECIFICATIONS FOR COMPUTATION SIMPLE CASE/COMPRESSIBLE Case #8101;
Data Evaluators:
Data Takers:
M. Rubesin,
Various,
C. Horstman
composite curves
WICTC UL I4.fSWAT 7144l 900@.
he.. A
.Iit"to
l H. Labost.
Sad C. Ist.tlu..
welocity
*'Sej
T:l: t
b
o..is Flow 0-.
fla t Plate
Ic:l
d U.li)."
i"-
Ot
7-Lo 1.s
aC/,,
DateCleo Ta,,,
¥arte•,
Tes om
tr7
sis
of Cp
Rag/osto.C.et
•
••
,•• IIOth
er
Mtott of easeressibillty o4 Oki. tttctin.,.
data tadlrs
Plot
, Nomtes".
Ordinate
Abscissa
Range/Position
Cf/Cfo 1
M
0 < Cf/Cfo < 1.1
Comments
".
.
•°
Skin friction vs Mach Number.
0 < M < 5.0
Cfo - 0.002634. to
Special Instructions:
I.
This
test
adiabatic example, number
case
considers
flat
plate
moving
the computor is range
friction
0
< M <
ccefficient
5.
At the
-7-
M vs
SVTw w
T.
5 log
is
Computors
the
atmosphere
r -
at
should
compute
the
(Taw - T.)/(TT - T.),
M -
layer
speeds.
ratio of
the
value, 1, 2,
4,
this
the Mach
local
both
3,
on an
For
of 15,000 m in
ircompressible for
boundary
high
flight at an altitude
KArman-Sch~nherr
Taw
turbulent
skin-
evaluated
5.
should also be plotted as a
is the adiabatic wall temperature,
TT is
the free-stream temperature at the prescribed
stagnation I
altitude.
condition, the computors are to plot their velocity profiles as (yir-_ --/v) Note that the recovery factor and velo-'ty
-
10
profiles are output only. 2.
the
of
Reynolds number of 10,000,
The recovery factor,
and
through
Computors
the
function of Mach number. temperature,
development
to consider
to
at a momentum-thickness
/
the
are
requested
Data are not provided for comparison. to produce
the
following
additional
data for the purpose of checking consistency of models.
375
results
not
backed by
P.
Ploc
Ordinate
Abscissa
A
r
M
Range/Peaition 0.5 < r
< * 5
0 < M < ).0
Comments Teccverv factor vs Mach number. Output only.
+y+ B
U*
logl
0 <. U,
0
10,
< 30
y. y* +
Velocity profile at H - 5. U - ;J p dU, w -wall.
U*+
0
U*/VT-7• W
y
I--.
+
y
W
w
w
L-2
376
FOR COMPUTATION
SPECIFICATIONS
SIMPLE CASE/COMPRESSIBLE M. Rubesin,
Data Evaluators:
Case #8201;
Data Takers:
Horstman
C.
Composite Curve
Various,
PIC'TOLAAL*U&h Y
Flow 8200.
Dote 3val..toret N. I.dboete &ad C. Hlorotmo..
c Floe Oer a Flat Plate (Cooled U411)."
*2 oerrso
NA.r of stoatio
VelacIty
Turbulaen.
Meao4sred
Profiles
ti8nt
dplo Co_
let.. Taker
lartso0
"
dtt -
Test Rig_____r___
_
Ceo- try
I
C:
Cf
t~
0
tio
2.
(teNo. tff.~t of urfat•e cotlr.4 ki dktefrletso.
d"to telrs Cf/Cff
Plot
Ordinate
i
Cf/Cfo
vi.
Tu/T,
Comments
Range/Position
Abscissa
< Cf/Cf 0
Tw/T
0.2 < Tw/Taw < 1.0
Cfo - 0.002634.
Plot at M a 5,
< 0.8
At Re a 10,000.
Special Instructions: the effect of changing
i. This test case considers
For the case of the flat plate moving at a Mach number of 5 at
plate in Case 8101. an altitude plate
of
Reynolds number of 2.
Computors
are
the computors
15,000 m,
temperature
temperature of the flat
the surface
on
'ocal
the
the effects
should compute
skin-friction
coefficient
of altering the
at a momentum
thickness
10,000. to include
requested
the
following additional
results
not backed
data for the purpose of checking consistency of models. Plot AU*+
Ordinate
Abscissa logl
0
y
Comments
Range/Position 0 < U*+ .lgloy
< ?I +
Velocity profile at
M
5
Tw/Taw a 0.3. T aw"-is adiabatic wall temp.
U* se
U / 7
dU
0
U*+
y+
U*/w
Pw
W
W
w
W, w
377
,
aswall
and
by
-~1
IN AN AXISYKMETRIC INTERNAL FLOW Flow 8400 Cases 8401, 8402,
8403
BOUNDARY LAYERS IN AN ADVERSE PRESSURE GRADIENT IN TWO-DIMENSIONAL
FLOW
Flow 8410A Case 8411 Data Evaluators: M. W. Rubesin and C.
C.
Horstman
S U,%MARY (presented
by R. H.
Feenholz )
INTRODUCTION These nominally
two-dimensional
or axisymmetric
layer
flows along
among
the variable-pr-ssure-gradient,
AGARDographs along
straight
223
and
253
aerodynamically
information lence
and
1y
level
in
AG 253
serve as a test AG 223,
while
Case 8401. Peake the
inner
pressure
et
of
Cases 8401,
of
four
8411,
cases
adiabatic
C.
presented
1980). walls
were
Horstman from
boundary
of
or clot
the
contain the
--
minimum In! n
and 8402 are described
No turbu-
ey-eriments
provides an ideal set of
flows
in
layers
unseparatpd.
layers
None
boundary-
and discussed
The
tunnel boundary
(environment).
and 8411
the
Rubesin and C.
(1977,
the
turbulent
urements *Pation to
below as presented
in
the dpscription of Case 8403 was given by Kussoy et al. (1978). Peake et al. (1971), (CAT 7102)* al. (1971) made their measurements
surface field
in
of the
a
cylinder mounted axial
and
profile 01 departs
considerably
Herman-Fottinger D-1000 Berlin 12,
Inst'tut fir W. Germany.
'This
Finley
section
8402, 8403,
but three
case.
and
uominally
test
by M.
reflected-wave
the state
the
listed below as Cases 8401, as defined
and
about in
selected
Fernholz
smooth
is available noise
walls were
compressible
summary is
based
normal
on
the
in
direction
ýn information
und
in
shown
of in
layer generated
the Fig.
wind 1.
tunnel. The
law of the wall (see Fig.
Technisrihe
on Yne
i:litial 2),
and
Universitr4,
vublished by Fernholz and Finley (1980). for the
AGARDograph 223. 378
OS1
is
Fluiddynamik,
VThis case was not finally selected as a test case set is, however, in the Data Library. *'This number denotes the experinient
boundary
centerline
from the logarithmic
Thermo-
the
198t
Conference.
The dat3
this
departure
profile
of
from the
tne
log-law and the difference
zero-pressure-gradient
wise pressure gradients, Discrepancies
since thý normal
case may therefore
by the presdure
may also,
in
part,
increase in
spring
pressure gradient
between
profile 01 and the
I.•itial
be caused by adverse
stream-
the normal direction,
from the resulting errors
will result
in
in
the Mach number
or by both.
data
in
reduction,
the outer
region
being less thnn that calculated assuming constant pressure. Profile For
this,
there
02
is
and
in
the
may be errors
longitudinal
and
a
region where
succeeding in
normal
profiles,
the skin-friction
normal
pressure
pressure giadients
the
slope
values.
gradients,
of
the
should
inner
region
Profile 03 is
this
time
of
a
be
negligible.
supgests
again subject
sense
to cause
to both the
numbers
in
plot
again much as would be expected of a subsonic adverse-pressure-gradtent
The
is
the outer region to be greater
succeeding
profiles 04
and 05,
in
than assumed.
The appearance
a zero-pressuce-gradient
thing-more as expected of a favorable pressure-gradient Case 8402.
Lewis et al.
The
tests
were
of
the wind
centerline
causing an adverse al.
(1972)
of
proifles
The
gradient (cf.
W
behave 'U
profiles
and--after
of
the
in
show a
an
both
change in
boundary
pressu:e
by a
favorable
most
of
by
of
a
sLress
van
cylinder
one
directly but
to
Driest
equivalent (1951).
mout.
Fig.
with
the
behavior
pressure
5 and the near
gradient
the
log-law
(Fig.
used
(FI
3).
station-
4
13
of
14
the
effects
plots shown
and
and
in
shows
et
the
5)
calibration All veloc:ity
and
their wake boundary
specific
of
r-essure
upstream
history
AG 253).
The devel-
"simple wave
effectcr.'
low-speed adverse pressure-grallent
K..
velocity
press'tre-gradient
characteristic
outer law
the
Lewi_
incompressible
.
gradient--the
on
the curve-fitting
However,
variable
,d
imposed by a cýnter body,
a favorable
incompressible
in
layer
pressure
the outer
region with
surface
applied
by
Profiles 08 to 12 show the classic the advezse
shear
very well
as
layer.
appear--if any-
flow on the log-law plot.
gradient could be
followed
(1969)
suggested
agree
the log-).w plot
opment
H1irst
as
inner
A pressure
the wall
region,
7201)
the
gradient
.acn
on the log-law
Stanton tubes was presented as evidence of consistency.
therefore
rorr, )..,-ts •
und
transformed
function for the
ýa5-2
pressure
Coles
(CAT o.
tunnel.
did not measure
procedure profiles
(1972),
performed
that
behavior.
The"
stops at or jiust downstream of station 14 to be followed
gradient.
Consequently
part of 13 are in
the pressure-gradient
fact
in
parameter
the
whole o(
a simple-wave,
profile
favorable
I% unchanged betwcen
This case was nit finally used for the 1980/81 Conference. in the Data Library...•
34 aud probably
pressuce-gradient"
12 and 14!
The data set is,
however,
379
-
.
.
.
.-.
.
.
. .
-
-.. .
"..
- ---
-
... -
-
-
-
---
-.
(CAT 7802 S)
K1Qfh,, et Pl. (1978),
Case 841j.
The test boundary layer was formed on the inner surface of a cylindrical
sttng-mounted a
lowed,
by fitcstly a
bodies
could
constant-pregsure
of
tunnel
the
so
centerllne
the tunnel wall about 2.90 m
The center bodies traversed
their x-position relative to the nose of the center body. by about
given by
"stations" is
The position of measuring
throat.
pressure
their associated
that
fixed instrumentatiort port in
fields moved past a single, downstream
the
along
traversed
be
The center
finally an expansion.
and
re.gion
to
geometry al--
where
followed,
layer
boundary
on the
compressien
shock-free
impose
The center bodies were designed
scction.
test
on the axis of the
test section
One of six center bodies could be
exit of the axisymmetric. nozzle.
to the
attached
(1978).
et al.
that rr.,de by Kusso,
is
study
fully instrumented
A particularly
0.22 w, and over tiis distance the thickness of th, boundary layer entering
the interaction varied by about 6%. and IV st
cases (ctnter bodies II
Two of these
include full
The wave structures produced in
aL close stieamwise intervals.
profile measurements,
35.3 x 106)
Re),
The wave structures are
b(oh cases consist of a ceutpr(ssion followed by an expansion.
in ihat the streamwise extent--at any given value of y--is of
relatively concentrated,
the same order as the boundary-layer thickness so that the "reflected wave" region is entirely submerged in the boundary layer. .The static-pressure
as
runs
from wall-pressure incoming wave at
y
120 mm (Fig.
Fo.
is
6),
before
expansion
wave
profiles
(10-13)
from profile
is
The
runs.
- 0)
not
reach
wall,
te
affected.
The
to
level although
outgoing
causes by about
change that it
gradient--the wall presceazhes
the compres.,ion
rises as
then
the end of
the wall test
'he
part
the outer
the
of
initially
wave
reflected
An
are not great.
diffex,-nces
series 01--the irore moderate pressure
cont inuing at a coastant
dues
(y
the wall
de-ending on whetl.er data are taken
leads the wall-pressure
60 mm
-
co.,itant,
initially
reflected
or
In
corresponding to a traverse well outside
60 mm
There are Lwo values for Pw'
the boundary layer.
sure
y -
ilso are values for
profile measurementa.
in the flow direction at
each case Lie stbtic-pressure distribution is shown,
form of
the
it.
fieldr, are shown
and is The
zone.
downstream more
appears
concentrated and stronger than might be expected (see the "bulge" in the inner part of profiles 0"3 and 09). Nwo
values
allowing for senting
the
for
the
diuplacement
varying static aithors'
61
surface
are shown,
pressure as suggested
valuest
as
calculated
for D STAR calculated
§7 of AG 253,
in
for
one
a
zero
the other repre-
normal-pressure-gradient
This case will be presented in a suppl(mentary volume of the data catalogue in AG-223. SFor the definit '4 of 14-15.
the displacement
thicknesses
38
-
6,
and D STAR,
pp.
see AG 223,
I
. -
- .-
*.'
-
-.
.
-
.
case.
It
is
interesting
suggests
a
pressure
wave
marked
sign
the
approaches
compression-expansion little
that for both series 01 and 02,
in
aip
of
displacement
the
wall.
wave would
any such
If
surface
this
in
were
propagate outwards
structure
either
the conventional expression the
in
zone
fact
where
the
present,
from the affected
in
the
static-pressure
that
any
attempt
an
incoming
expansion-
area.
There is
profiles,
or
in
the
wall-pressure variation. It
is
evident
from
history effects
in
thn. particular
part
sions are
the
the
foregoing
velocity
of
the
comparable with
profiles must
layer
take
into
under discussion.
the boundary-layer
at
accounting
consideration
In
for
the
pressure
history of
a wave structure whose dimen-
thickness,
the
past history of the inner
and outer layer3 may be very different. For after
*
the
more abrupt
an initial
pressure
constant
expansion
wave
described
by
then
the
pressure region
reaches
last
gradient
two
the wall 8nd
profiles
(13
wave
again
reach:.s
Both here in
is
a
localized
the wall.
and to a
The
dip
the
authors' if
for series
not explained easily in
this region,
the
(10 to
12)
but the
in the region a strong
com-r
the last profile.
6,
value
where
anything,
shows
the
01,
wall pressure,
evidence of
the compression
reverse
the wall pressure
tendency.
seems a
little
low
the ii..er part of the boundary layer
in
a
te-rms of the wave structice.
The observed pressure variation suggests that there is wave in
7)
falls markedly
There is
the outer part of
relation to the general pressure level in
way which is
(Fig.
rises to a plateau
14).
D STAR value,
lesser extent
02
-he pressure
and
in
series
(02),
pression wave entering the test section in There
of
or alternatively that
. weak outgoing expansion
the probes are affected by the wall and the
wave structure so as to give a ulightly high reading when close to the wall. Wall-law
profiles
Profiles
02,
structure
and
position in
04,
a.'e shown for
and
appear
03
are only
as
typical
the log-law plot.
series 01
slightly,
and 02
(Figs.
if at all,
at
the start
and 9,
affected
zero-pressure-gradient
07 is
8
respectively).
by the
profiles
in
incoming wave
both
of the adverse-pressure
shape
and
gradient as
observed at the -gall and 09 at the end. Series
02
shows
the
profile of 03 develops pressure
gradient
at
same
Zwarts nel.
the wall,
(1970),
(1970)
conducted
(CAT
splitter
through
a
.',e
Initial
by 07,
zero-pressure-gradient
at the start
increasingly
of the adverse-
exaggerated
in
profiles
where tle wall-pressure gradient
is
favorable.
constanc
his experiment
on the Mach
09
7007) on the
floor of a 0.13-m square wind
plate was designed by the method of characteristics
a Mach number distribution passed
which becomes
12 and 14,
Zwarts
A contoured
behavior.
an increased wake component
and 10 before decreasing in Case 8411.
general
tunnel
floor
number gradient
such
that the
falling
ta
initial
tun-
to give
flow at
M6
4
3 over a distance
-
of
381
- - -
-
-
..-.--
-
--
. .
.-
:
-
.
.--
"- - "
.,.
.
-
- -
-.
*.- *.: ----
-
.
* --
-
"
-*
.
~
..
.
'
*.-
-.
"
I
flow
considerable divergence In
as well as
region
adverse-pressure-gradient
number
Mach
constant was
there
that
showed
tests
visualization
of
region
by a second
followed
0.13 m,
flow.
Surface-flowthe
in
convergence
the zoro-pressure-gradi.ent
This was attributed to inflow/outflow from the tunnel sLde wall driven by the
region.
about 8).
the tunnel floor is
pressure gradient
The
ratio of
normal to the test surface (length-to-width
pressure differences
significant
be
imposed as
is
negligible
gradicnts
should
gradients
(profiles 03,
15,
and
at
except
a
reflected
so
wave,
start and end of
the
that
the adverse-pressure
Unfortunately no static-pressur,
16).
normaL-pressure
traverses were
carried out. offers
The author We
tions.
data
selected
have
values
skin-friction
evaluated
the lo.arithmic law is that the
the
from
which gives the smallest lalues of cf.
(1966)
from several
deduced
TR-method
of
is
skin-fricticn velocity
and
Hopkins
Kenner
Agreement of the velocity profiles with
10) though almost all profiles lie low,
fair (Fir,.
func-
calibration
The outer-law
sLill too high.
which means
representation
is
11, iniikatLing clearly upstream-history effects.
shown in Fig.
ADVICE FOR FUTURE DATk TAKERS Experimentalistu cDmpressible AG 223, As
turbulunt boundary
253,
in Vol.
further
ted with skin-friction measurements
in
(to be published 1c;81). ilows,
repeated with cooled walls
Before Going this the problems connec-
in adverse- and favorable-pressurd-gradient
The environment,
i.e.,
turbu-
curves for
thL noise level and the turbu-
In order to allow for a complete computation of the
ence level in the test sectiou. boundary layer,
-
two-dimensioual
layers must be solved (measuring techniques and calibration
boundary
Preston tubes). We have to know more about -l
in
for the two boundary-layer
Both experiments should
with isothermal and variable wall temperarure.
"lent
experiments
this serfs
III of
suggestions
presented here a few
are nppropriate.
8402 and 8403,
perform
layers will find hints about gaps in our knowledgE
when available,
and,
for the cases
to
intend
who
Existing
location and length of the transition region must be known.
turbulence models can only be improved if more and reliable turbulence data are perFor this flow we would also Here we have a large deficit with Case 8402. formed.
.
like to see measurements of stati(: pressure profiles at least at critical stations. Finally it
order to be able to study compressible boundary layers near separation or relaminariThis latter type of flow is certainly most for a favorable pressure gr.dient.
*"'"zation
*..
would be advantageous to have flows with steeper pressure gradients in
rewarding though it
.
of flow cases under consideration.
does not appear in the list
38' !-... .
.
.
.
.
. .
.
.
.
.
.
.
77
"
7
.
ACKNOWILEDGRENT This
summary
In AGRDographs
presented
at
223 and 253.
the
1980 Conference was
The author
based on
thanks his co-author,
information
J.
P.
Finley,
recorded for per-
mission to reproduce the in~ormation from these two reports. REFERENCES Coles, D. E., and E. A. Eirst (1969). Proceedings, ou Computation of Turbulent Boundary Layers, University, Stanford, CA, 94305.
1968 AFOSR-IFP-Stanford Conference Vol. 1I, Compiled DAta, Stanford
Fernholz, H. H., and P. J. Finley (1977). "A critical turbulent boundary layer data," AGARD-AG-223.
compilation
of
compressible
Fernholz, H. H., and P. J. Finley (1980). "A critical commentary on mean flow data for two-dimensional compressible turbulent boundary layers," AGARD-AG-253.
-
.
Hopkins, E. J., and E. R. Kenner (1966). "Study of surface Pitots for measuring turbulent skin friction at supersonic Mach numbers--adiabatic wall," NASA TN D 3478 (CAT 6601). Kussoy, 1. I., C. C. Horstman, and M. Aclarys (1978). "An experimental documentation of pressure gradient and Reynolds nu:rber effects on compressible turbulent boundary layers," NASA T4 78488 (CAT 7802 S). Lewis, J. E., F. L. Gran, and T. Kubota ;1972). "An experiment on the adiabatic compressible turbulent boundary layer in adverse and favourable prassure gradeints," J. Fluid Mech., 51 657-672 (CAT 7201). Peake, D. J., C. Brakmann, and J. M. Romeskie (1971). "Comparison between some high Reynolds number turbulent boundary layer experiments at Msch 4 and varioub recent calculation procedures," Nat. Res. Council of Canada and AGARD CP-93-71 Paper II
(CAT 7102). Van Driest, E. R. (1951). Sci., 18 145-160.
"Turbulent boundary layer in
Zwarts, F. (1970). "Compressible turbulent Univ., Mech. Engr. Dept. (CAT 7007).
Wall pressure
01
02
03
boundary
compressible fluids," J. layers,"
Ph.D.
O0 05 06
.. 0-04
...... Profile
Figure
6 'OSt' 0 '06''
Sketch showing measuring stations (from AC 253).
1.
383
-.
.
,
.•
..
..
.,
.
-
.
,
-
.
.
,
McGill
, ""
I'
Wave struclure
A
Thesis,
Aero.
*.
.
Lz2~zp
294 22_ 20-
~-
I0
14
-
01
2.91 1.90
-0
02
4 '.0r
0
07 1.90 VU2 2.
.
W00 I0go$
)9116 6
yUa/ V, Figure 2.
Law-of-the-vail for a compressible boundary layer (adiabatic wall, adverse pressure gradient, defined origin); Peake et al. (1971). c, from Preston tue
frmAG25)
At.
.-
4
Figure 3. Wind-tunnel model.
1<6 ~+ .9 711 1.21 291
Ic
2
a
IV0
2
9
0
. *
0
WP
.
2Gal 09
0
9
YU*/Vw Fig'ire
4. Comparison of log-law with measurements (Lewis at a!., 1972). Adiabatic wall, variable pressure gradient (axisymmetric configuration); (from AG-2 53). 384
iv Ti'
-
&-MX,
_I.1011
9
a.8 1 0 .2
04
I
0 VI 2
04 -.
Figure
5.
Law-of-the-wall for pressure gradient,
1
I
.0
04
2.4
0 0.
11
a comupreassble boundary layer defined origin); Lewis et
_ I.~p ITA __ transformed log-law "..2 03 (from "5 - 4AG--253).',,' 0 8 U Q 1
__
(adiabatic wall, adverse,•2 al. (1972). cI from.'"
_
2
p
2.2
0-4'0
IL,
*.
di0)
Figure 6.
02
.PITMOI,-
.A 0
V
Pressure distribution in 0 C 02 Os0a wave-interaction 0 0W 04 01 ' '2 2 region--Series
01 (from AG-253).
,'
'2'
~KV4~L KP.4
Figurn
7.
Pressure distribution in
wave-interaction
~
~k
region--Seriee 02 (from AG-253)..,.
385 i L00l
.....
•,~ ~ 00+ .18, 12212.1s
I
I.
,"4
,2 2-
2.
'
--_
"
I0
II -,
yU*/vv I.-
Figure 8.
Law-of-the-wall wall, variable
(1978).
for an axisymmetric pressure gradient,
compressible boundary layer (adiabatic origin not defined); Kussoy et al.
cI from heated-wire gauge (from AG-253).
+I"Of 022 0, 2
U+
4 26 4
2.802t,01 2.01
24002
,,A
1.05
14$",
21.I It-
0
2.0
1'0 $
l2o.
22 0
2.0,4 2.01 -.O 1.0)
894
"
2•4. 2
I I
I
1-=
_.* -
_____.
0-0 ., ., 193,1,. 7,,
oTT
-" :"
Ul I
241.--+.--
C...I:
,
yU*/vV
Figure 9.
Law-of-the-wall for an axisymmetric compressible boundary layer (adiabatic wall, variable pressure gradient, origin not defined); Kussoy et al. (1978). cI from heated-wire gauge (from AG-253).
"386
o
-•-
--
I'
..--
.
-
.
..
.
.
.
I
-
Io°
.
U-... -.
..
26:
9
30
.
0.,
6--.
-l
-u'o*-."
-U
2
e •:.." *
.:
'o6,
0 V
5
6
I~
•
2
i
1
*'gft
--.
•
~
l
I~l
.
. . ,
•, .
_.. I
Figure 10. Law-of-the-wail for a compressible beundary layer (adia~atic wall, adverse pressure
gradient,
origin
nut defined);
*
*
Zvarts
(1970).
c,
from Preston
tube (from AG-253).
f:-2-
:','.', Figure i,',•:,:pressure
I0.Lwouter tu(bre
hl-wallfor a compressilbe burtlert boua~ye gradient (daai origin ~l, not defin~ed); AfrG-A-23)."-
187
*
I
lyr Zwarts
ini:al wanl
(190)rm
adverse 97 ret),.
BOUNDARY LAYER IN ADVERSE PRESSURE GRADIENT '"
AN AXUSYMMETRIC FLOW
Flow 8400 Case 8403 BOUNDARY LAYER IN ADVERSE PRESSURE GRADJENT IN TWO-DIMENSION.&L FLOW Flow 8410 Case 8411 Data Evaluators:
M. R. Rubesin and C. C. Horstman
SUPPLEMENT (Prepared by G. M. l.illey) to the Summary Pres-ented by H. h.
Fernholz Concerning
cst Cases 8403 and 841) CASE 8403 The
tet-t boundary layer in this flow (3kee Fig.
constant--diameter
tube or-er an extensive
stream Mach number of 2.3. sý%apad center body,
in
range of Peynolds number at a nominal free-
The region of adverse pressure gradient was generated by a
and its magnitude was greater than in thc
measured wall-pressure conducted
1) is formed on the inside of a
distributions
the NASA-Ames
Resaarch
are
listed
Centec's
in
the data
other test caseb. files.
Thi
high-ReynoldE-number
The tests were blowdowun
faility
and are reported in Acharya et al. (1978a,b); Acharya et &i. (1979); and Kussoy et al.
"(1978).
Th.e tube diameter was 0.2417 m,
run time in
the facility varied
and the length was 0.27 m.
Erom 5 to 60 nin.
The range of stagr.stion pressures
was 0.33 to 9.0 atm, giving a free-stream unit-Reynolds-number x 106 per meter.
The useful test-
range of 4 x 10
to 108
Th1- total temperature wa3 278°K.
The measured upstrzam boundary-layer profiles verified that the flow in the test region of the
tube was fully
the initial boundary-layer four test runs, slight
turbulent.
The
characteristics at
free-atream x -
test conditions,
0.1 m,
are listed in
each at different values of stagnation pressure.
Mach-number
gradient
(-0.05/m) existed ahead of
including
Table I for
In each test case,
a
the interaction due to bound-
ary-layer growth in the tube. The surface roughness on the inside of the duct was approximately 0.4 we and was an order of magnitude
less than the minimum (linear) sublayer thickness encountered in
these tests.
"Instrumentation and
Measurement2
The wall static pressure holes were 0.050 cm in diameter and were spaced at in-
-
tervals of (2)
5.08 cm along the tube.
heated-wire
technique,
Preston tube was 0.152 cm.
and (3)
The wall shear was measured by (1) law-of-the-wall plots.
The outside diameter of the
The platinum-O0% rhodium heated wire was 0.000254 cm in 388
-*.
* --
* >.-...
Preston tube,
-..
.. .
.
.
.
..
L4
diamecer
and 0.635 cm long.
temperature
traverses.
and a width,
parallel
The to the
The flow field was measured
from Pitot pressure and
miniature
total thickness
surface,
Pitot
tube
of 0.10 cm.
probe was based on the design proposed by Vas The
fluctuating
dual-wedge nents
quantities
hot-film
and
the
shear
o
stress.
a
of
The total-temperature
0.0127
cm
thermocouple
(1971).
were measured
probes were used
turbulent
had
total
by hot
obtain
the
Another
wires.
Both single-hot-wire
three fluctuating
hot wire
with epoxy
and
velocity composupport
measured
mass flow and total temperature fluctuations.
Benchmark Data The
tests were conducted
conditions Table 1.
and
the
initial
at
four values of
boundary-layer
The Reynolds number Re(x')
was
stagnation pressure.
thicknesses
The following measured quantities are included
in
a.
Surface (mean):
b.
/Pw=, "w/w Cf x l03 as functions of x, Integral boundary-layer prnperties: 6,
c.
0, (in
6*,
cm)
as
-
0.10 m
are
from the nozzle
given
in
throat.
the data files:
where
Cf =
I
"
2
functions of x.
p/pm,
p/p.,
T/T , U/C
,
pU/p
' , T T/T T
x-stations.
T
as
functions
of
y
at
various
T
Flow field (fluctuating)
(pu-'/)/p U., /o., (u--) /Uit (i/pU
2
(v-)/U/.',
(-W) /U_ c
u ,
" '
3
x 10.
The axial distance
nate y is
x
free-stream
Flow field (mean): M,
d.
at
based on the distance
The
x is
measured
from the
nose of
the center
body.
The coordi-
normal to the wall.
Uncertainty Estimates The following uncertainties are estimated from the basic measurement uncertaiý:cy:
Tw -15% y , *0.01 cm T,-
0.5%
t
p - ± 10% T - t 6% P - ± 12% U -±3% (u)
,(V)
,
(w)
t15%
±20% t
389
Si
. .!
:.i.
CASE 8411l This flow is
Case 7007 of the Fernholz-Finley
(1977)
collection.
The original
data were obtained by Zwarts (1970).
The test boundary layer was formed on the floor
of the NAE 12.7 cm x 12.7 cm (5"x5")
blowdown wind tunnel at a free-stream Mach number
of 4.
The test section commenced about 0.75 m downstream of the nozzle throat so that
the starting
boundary-layer
thickness
was
about
10 mm.
A compression wedge
in
the
form of a contoured splitter plate was designed to give a Mach-number distribution on the tunnel floor such that the initial flow at number-gradient region of Fig.
2
listed
falling to
M -
constant-Mach-number
taken in
from
Zwarts,
the data
files.,
3
M- 4
passed through a constant Mach-
over a distance of 0.15 m, followed by a second
flow.
1970).
A bketch of The measured
the apparatus
given below (see
test wall-pressure
The undisturbed boundary-layer
3.5 x 10 .
is
The test surface roughness was less than 0.9
keynolds number is
is
R-
wag not actively cooled.
and it
pm,
distribution
The wall temperature was not measured, but was assumed to be between room temperature (same as total temperature) and the adiabatic wall temperature. The length-to-width ratio of face flow-visualization region of the adverse Iw
tests
the tunnel floor (test birface) was about 8.
showed there was considerable
pressure gradient,
ze-o pressuce grddient.
flow convergence
as well as flow divergence in
The data on file,
however,
are presented
Surin
the
the region of
for the centerline
region only where
the transverse Mac), number gradient was small.
tunnel centerline,
measurements obtained from pitot traverses and Preston tubes showed
differences
in Cf and 6",
from their centerline values,
At
38 mm from the
of up to 10% and 5%,
respec-
tively. No Reynolds
boundary-layer -number
would
trip was ensure
used,
fully
as
it
was presumed
turbulent
that
boundary-layer
the prevailing
flow
a
short
high
distance
downstream of the throat. Instrumentation and Measurements The test wall was provided with 48 static holes of 1.04 mm diam. the test surface outside
the range
diameter were used
wall normally, were
in
grouad
x -
0
to
These
0.4318 m.
for the profile traverses.
and were curved to finish square.
x -
probes
parallel
were
Pitot probes of 0.419 mm
The probes emerged
with the surface;
also used
They covered
as
Preston
from the
their end faces
tubes.
Additional
Preston-tube data were obtained using a pitot tule of 0.813 mm diam.
°.1 tA fuller description ot this flow is given in AGARDograph 223. -Data on file prepared by M. W. Rubesin and C. C. Moffett Field, CA 94035. '""
390
-iorstman, NASA-Ames Research Center,
Pitot-tube displacement and shear corrections were applied.
see Zwarts
For details of temperature measurements,
(1970). .
No turbulence measurements were made. Benchmark Data 1.
this test case were as
in
The free-stream flow conditions Free-stream Mach number
Free-stream total temperature Free-stream static
temperature
Free-stream velocity Free-stream static
pressure
Starting values of boundary layer at
x
4.02
TT
-
0
295 K
T.
-
0 69.57 K
V_
-
672.2 m/s
p.
-
9.455
.1
x 10
N/M
2
-*1
cm:
Total thickness
6-.
-
1.088 cm
Displacement
6
-
0.447 cm
e.
-
0.056 cm
thickness
3
275°K
-0.635
Momentum thickness
2.
M,
Tw
Wall temperature
follows:
IA-
The data file contains values of:
e,
Cf,
H, Ue,
and Me as functions of x and v.
a)
P,
b)
profiles of U/Ue as functions of y at selected x-stations.
The x-coordinate is
measured in the streamwise direction from a.i arbitrary lacaThe skin-
tion in the wind tunnel.
The y-coordinate io normal to the test surface.
friction coefficient Cf is
defined with respect to properties external to the boundary
layer
'-4
I 2 Cf
w/2
•
Ue
Uncertainty Limits"-
The uncertainties,
estimated from the basic measurement uncertainty,
are as folq
lows:
Cf
10%
U
H
f2
3%-
*5 391
391
•? .'. "-." :,? -'-?. ::.- 'i",
-:
'-.
'. --" "- - "
"
'-
"- ' ' - . . .
-
"
Table I Free-Stream Test Conditions PT (N/ Test Conditions
..
)m
31600
97070
302900
901500
278
278
278
278
2.21
2.24
2.33
2.36
2909
8528
23111
65638
T. (K)
140.5
138.6
133.2
131.4
Tw (K)
278
278
278
278
p. (kg/m )
0.0723
0.2149
0.6045
1.7399
U. (m/s)
525.3
529.2
538.8
542.1
TT°K M. 2
p. (N/m )
L
2
6c (cm)
4.0
4.0
4.0
4.0
60 (cm)
0.97
0.85
0.85
0.80
0o (cm)
0.26
0.23
0.23
0.21
Re (x')
11.7 x 10
Re (60) Re (Bo)
o
16
i666
1 .
0.16 X 106
35.3 x 10 0.49 x 10 6
105 x 106 1.44 x 106
314 x 10. 4.32 x 106
1.04 x 10
2.82 x 104
8.28 x 104
22.7 x 104
REFERENCES Acharya, M., M. I. Kussoy, and C. C. Horstman (1978a). "Reynolds number and pressure gradient effects on compressible turbulent boundary layers," AIAA Paper #78-199. Acharya, M., M. I. Kussoy, and C. C. Horatman (1978b). "Reynolds number and pressure gradient effects on compressible turbulent boundary layers," AIAA Jou., 16, 1217.
1
Acharya, M., C. C. Horatman, and M. I. Kussoy (1979). "Reynolds number effects on the turbulence field in compressible turbulent boundt y layers," AIAA Paper 79-4044 (1978) and AIAA Jou., 17, 380. Fernholz, H. H., and P. J. Finley (1977). "A critical turbulent boundary layer data," AGARDograph No. 223.
compilation
of compressib]e
Kussoy, M. I., C. C. Horstman, and M. Acharya (1978). "An experimental documentation of pressure gradient and Reynolds number effects on compressible turbulent boundary layers," NASA TM 78,488. Vas,
I. E. (1971). "Flow field measurements hypersonic speeds," AIAA Paper 71-273.
using
Zwarts, F. J. (1970). "The compressible turbulent gradient," Thesis, McGill University, Montreal.
a
total
boundary
temperature layer
in
a
probe
J
at
pressure
392
I. -I-i-[• 'iii~ i>l~.i :[ i[-"[il <2'i • i•"•i'i " [: 2'. -:.• -i •i> .', ""-"" J ,-rZ - ...- ' .,,, , , --. ' -,-.. - .,-- ,,,/,
.' -
, ,'.,
. .> -
" i,
."
-"
'.. ,'."
"- '. . . ".
-1
CENTERBODY SUPPORT
CENTERBODY MACH LINES \•_
INSTRUMENTATION PORT
i
'" SURVEY PROBE
Figure 1.
Test configuration
for Case 8403.
.APPROX.
19"
dr':
I
TRAVERSING PITOT TUBE
Figure 2.
.- MOVABLC
'TEST
"
WALL
Schematic of apparatus for Case 8411.
DISCUSSION Flows 8400 and 8410 1.
2.
3.
The Conference stated that high valL.as of the adverse-pressure-gradient parameter r and the large number of measurement stations were the principal, appropriate criteria in aelection of test casesTUB in this class of compressible flows. PITO The Conference agr Ad that Case 8401 should be excluded from the forthe highere e tae ththhva[•ofheder-pressure-g garadeter cases ln test cases b~cause of its questionable starting profile. E•an telagenubr f eauemntstton wrete ricia, ppopi3e,3 Concerning Case 8403, the Conference observed that, at downstreaia profiles, the law Of Lhe wall, ba'ed on measured skin friction, falls lower than L'>at of Coles,
..
SPECIFICATIONS FOR COMPUTATION SIMPLE CASE/COMPLESSIBLE H. Rubesin, C. Horstman
Data Evaluators:
Case #8403;
C. Horotman, M. Acharya
H. Kuasoy,
Data Takers:
a. Aveleateta: K. &*ba~tt &td C. Karsata. View VI~.00 We
'boooary
.
lAyer, is in Averse Presstre Gradioat is an hataymatrjr latarnui vie.,
amber of StaitonsKesewr*4 K
Came Data
V
d/dV of
Test hai
or4 V
mrrp
Taber
-
l
"
O
.
o4ther
C1
O•erl
a.11
CasB03
0.uar. orto_2._
H.
Notes
.i....
TO
_
(b"64dI
Ukr,,--i
friction dailta ;O{g
*.,* ..
,
Plot
Ordinate
Abscisma
-
1
Cf
x
Range/Position
2
0.0005 < Cf 3
Cf
2
0.20 < x < 0.40 m
X
Cf
0.'02
0.20 < x < 0.40 m
x
0.0005 < Cf <0.002 4
H
0.20 < x < 0.40 m 1 < H < 5
5
H
0.20 < x < 0.40 m
x
I < H < 5 6
y
U/U,
0 < y < 0.04 m 0 < U.U.
7
y
K/
0 < y < 0.04 m .< 0.1
C < ,C/U 42
2-/p o
8
0 < y < 0.04 m 2
0 < -1/p U 9
y
U/U.
< I
.Ca
Three curves for centerbody Ii at Rex
11.7,
35.3,
and 314 x 106.
Three curves for centeibody IV at Rex
-
?6
6
11.7, 35.3, and 314 x 10 .
Three curves for centerbody VI at Re
- 11.7,
6 and 314 x 106.
35.3,
One curve for centerbody II at Rex
-
.
35.3 x 106
One curve for centerbody IV at Rex " 35.3 x 10 6 . Three curves for centerbody II at x
-
0.1775, 0.3175 and 0.3975 m.
Three curves for centerbody II at x - 0.1775, 0.3175 and 0.3975 m. Three curves for centerbody II
< 0.0015 at x
-
0.1775, 0.3175 and 0.3975 m.
0 < y < 0.34 m
Three curves Zor centerbody IV
0 < U/U.
at x
< 0.1
i
Comments
0.20 < x < 0.40 m 0,0005_< Cf (O0.00
.
ptel-.'
-
0.144,
0.324 and 0.384 m.
394
• .• "-+'-.'-"..'.." ....-- , -'.-.": "-'.
,"......................."................."....................-..-.....---.,-.",.....
•, /-i',2-',-,i'-2'+i-l~'-i-i--'-'.i2-:-i--i+.i.i-.'2--'2,."~i,,.....................................................
,' •
"---......-........
--........
1
•'
Plot
Ordinate
10
y
Abscissa
Range/Position
AK IU
0 < y < 0.04 ra 0 < r~/U_ < 0.1
11
T/P U 2
y
0.< y < 0.04 m < T/00_U _
0
Comments Three curves for centerbody IV at x
C .144, 0.324 and 0.384 m.
Tnree cktrves fur centerbarly IV
< 0.(.i15 at x
-0.144,
0.324 and 0.384 m.
Special Instructions: Cf This *
r
2~(-0OO
test case considerer a ieries of
several different
Itevaiolds
numbers.
The
a1IYtqM.AVtrir. advrerse pressure gradient's upstream conditions.
Boundary-layer edge conditioniq are calculn~ed us~ing
0 cm.
the prescribrd wall-ptessure distribution.
are prescribed at x
inenti'opic
relationis
K ~is defined ýnrT~able 1 above.
PLOT 1 CASE 8403 FILESý 2,3_5 CENTERBODY 11 Re
14x10 1
315.3xl0 6
=11.7x10
0.0020
C, L
0.0 01i5;
00 00 0
.0
0.0010
--
0.2
0.3
0.4
0.2
0.3
0.4
x (in)
395
.
..
.
.
.
.
.
.
.
0 .2
at
C.3
0.
from
PLOT 2 CASE 8403 FILES 6,7,9 CENTERBODY IV .7 Re x
06
3
O6
6
6
35.3x
li.7xiO
314x0
6
L, ,
00
0.0020
0.0015
0 0
0-
0
0
t1 0
0
0
0 I
0.0010-
0
S0.?
0.3
',
0
0
0 000
-
0.4
I
0.2
0
1
00•
-
0.3
0.4
0.2
0.3
0.4
X (Mn)
IV PALOT o Cf 3 CASE 8403 FILESo 10, 1.1, 13 CENTERBODY 0.0020 I- Re
.6
- 11.7 l
35.3 l l
I
0.2
0.3
o
0.4
0.2
0
0.3
314x106
0 0.
i
0.4
396
0
r
0.2
0.4
0.3
0
000
0.0010
0.2
00
0.3
0.4
0.2•
0.3
0.4
x (M) 396
0,2
0.3
0.4
".-
.-
*
L_.I PLOT 4 CASE Re
8403
0 0~00 o-I
40
-
Re•
0
.
02
0.
2-
-L2:0.3
0.2
0.4
00
CENTERBODY VI
97 PLOT 5 CASE 8403 FILE ,, 35. 3.._0'
Re
4
.- l
0.1
i'0
,A
35.3x10
-
4-
3
4 CENTERBODY I1
FILJE
0
5
00'_
V.9
r0
!.0 •':0 0
0.2
0o1
x
11i
. .
.
..
.
.
.
.
.
.
.
.
.
.
.
i2
___-I-____ _____
______
.
0
x (in)H
93 79
1
.
0.4
0.3 (n)
.
.
.
._
" --- ,.
.
.
.
.
.
,
..
0.06]
PLOT 6 CASE 8403 FILES 17,21,213 CENTERBODY Ii 0.3975~.
m03175
0.067
0
0
0-
0
0
L 0~0
0.04 0."0V.1,
t
t
.
co,)1
0.00
0.5
0
PLOT 000L r 0.02 0
0.5
0
1
7 CASE 8403 FILES 0.0775 m
x-
-0.3175
-.
0.5
0
1
1
-
33,37,39 CENTERBODY II 0 .. .. •.. T
00
.
O 00--
0.04. 0
0
0
0.00
I
°
Y
00i
<>~-. 0
~
0.04o--T-
S0"0
00
4.... . .
...
0
"
OD
o-
"
Q-5
0
K/-",•
-
0-D
0-
3 :-
oot
•
o
/_'H
PLOT 8 CASE 8403 FILES 33,37,39 CENTERBODY I1 0.02
0.6
-
4"
0
L
x " 0.1775 m
":.
:0.3975
0.3175
-,
"
0 44
0.04 {t
0
*
tt0
0 ,
0
y0 0.02
0
--
T0
m0
0.38
0.324
0
0.
0
PLO
.0 9AE80"
FIE
.
0 0
0.02
0,4
0.0
_1
-r
0.8
0.2 -
.
-
390
T
1 0.5
1
0
K-• I
-
1
0.5
0
0.5
1
---
k= '.
U/U399
S...*.-
':,
0
0-1..
j-
o
0-01--
0-
"0
0.04-
0.00
,.
00
Jr -01
II.. 0lm.0
r-
0.0
0
0.0
I
00
0
0.02
000 1 oENT.BO
0
0.001 .1.
0
0.001
0
.0 024283
•.
Li,
PLOT 10 CASE 8403 FILES 40,44,46CENTERBQDY IV 0.6 F
x
144 m
-0.
0.384
*0.324
0.04
0-~ 0
0
0.02 7 0-
~0
o %00 0.00
1.5
PLO 0LO 0.6 r
04
.L
0
m
-0.144
0
7.
-0.324
-
0
0
*
00
0
8403 FILES 40,44,46 CENTERBODY IV
0.05CASE x
00
+
0.384
0
C0
0
0
()
0
0
0.000
0.001
0
0.001 2
0
0.001
tr/p~~U 0*
4001
SPECIFICATIONS FOR COMPUTATION SIMPLE CASE/COMPRESSIBLE Case 08411;
Data Evaluators: Data Taker:
Flow 6400.
D4.S~ate 991seo va
. Kebost.and C. laretsas.
F. J. Zwarts
LQArY G toer I an
*I
Voloaity
dp/dm
Test 15.1 g Geometry
Data Taker
or U up
0
1. twarta
Plot Odinate
Abscissa
1
H
3
ex
x
Worse. pt..m"r. Credjost toI-Da 2-0
l,*mat
Flo.-
Trwbulstcs Protiles
1
or W
~
v1O -C-
.2
~
6
10te. C
r.
II.
(b4 Od
Range/Position -00
2
M. Rubesin and C. Horstuian
OCLOWNot..
A
Cmet
x < 0.20 m
_fx
-0.02< x
-0.02< x
4y
/U5
0
At x or0.01905, 0.09525 and 0.19683 m.
Special InGLructians: This
test
case
considers
a two-dimensional
conditions are prescribed at
-'upstream
are
calculated
using
isentropic
x
-
adverse
-0.635 cm.
relations
distribution.
401
from
pressure
gradient.
The
Boundary-layer edge conditions the
prescribed
wall-pressure
PLOT I CASE 8411 FILE 2
C9
f
0,0010
0.0000
0
0.1 0.2 x
(M)
PLO 29 AE99 LF&IIE0
.
j
PLOT 3 CASE 8411 FILE 2 0.0008 7-
L
i O.QC
x (
0
--
0.0007 I---
.0
y I-
O°0
-
0.2
000
,
-
0.01905
m
•.
0.09525
0.19683
"•
0.0005
-
L
0
01
-0
0 .
1
--
0
0 '
•.
-'
0
0o
°
-
-K
0
°-
'
">
U/I,.
040
. .......... .. . .•.'"..-
..
.o
.
%
-i
"
SESSION VIII
Chairtman
J. L. l~urdley
Technical Recorders: S. Pronchick H. Nagib
Flow 0370 Flow 0260
404
HOMOGENEOUS TURBULENT FLOWS Flow 0370 Cases 0371,
0372,
0373,
Evaluator:
J.
0374,
H.
0375,
0376
Ferziger
SUMMARY
In
the companion
paper
(Ferziger,
into three classes containing a total
1980)
homogeneous
turbulent
flows were
divided
These are as follows:
of six cases.
Flows with di.sipation only
1.
Case 0371:
isotropic turbulence
Homogeneous
Flows with redistribution and dissipation
2.
3.
Case 0372:
Homogeneous turbulence with rotation
Case 0373:
Return to isotropy after straining redistribution,
Flows with production,
a.
and dissipation
Strained turbulence 0374:
.,Case
-
b.
Plane strain
Case 0375:
Axisymmetric
Case 0376:
Sheared
strain
turbulence
CRITERIA FOR SELECTION
concerning which data are considered suffi-
This summary contains recommendations reliable
ciently *
The
criteria
for
(2)
the
be in
data
ferentiated the
data.
These
accurate
to
acceptability at
least
for
Case
be
used as
are:
(1) the
rough
from modeling); Except
agreement
the effects
(3) 0371,
the
for
targets
data
from
computational modeling.
different
agree;
experiments
with generally accepted
theory
(as dif-
extend beyond the uncertainty
reported
the data do not meet all
of
of
and the
these criteria,
are therefore made with reservations.
recommendations
"* "*
and
flows are
number.
The
results
will not
be presented
(precise modeling)
amenable to accurate simulation without modeling at low Reynolds of
such computations In
here.
were
the opinion
not
of
reviewed
Ferziger
(1980)
and
computations of this type
the author,
should be considered as complementing
in
the experimental results,
and
should be used iti the future as a check on modeling. All of the
They are
tation.
*
data. been
flows
In
all
to
cases,
provided
along
are to
be
as homogeneous
regarded
t
be simulated from time the initial with
any
- 0
flows
to the
values of the components other
data
about
the
for purposes of
final time given with
of the Reynolds
flow
compu-
needed
to
the
stress have
carry
out
the
!* Mech.
Eng.
Dept,, Stanford University,
Stanford,
CA
94305.
405
..............................................................................
In order that
simulation.
have further provided an estimate of the dissipation at the initial time.
These were
ffound by the prereat author by curve-fitting the data and difierentiating
the result.
The values
*
20%.
..
It
for dissipation must be regarded as having an uncertainty on the order of recommended that the computors use the values provided;
is
one of
This is
well established than 20,
any adjust-
HOMOGENEOUS ISOTROPIC TURBULENCE
CASE 0371. -
if
they should be clearly stated in the entry papers.
ments are made,
_
we
start with the same initial conditions,
all computors
flows in
the best-documented
the
It
literaLure.
turbulence
is
at least at Reynolds numbers based on Taylor microscale greater
that,
the turbulent kinetic energy decays azcording to the power law:
~q22
•o-.
(t
- to-n.)-n
The exponent is well established as 1.25 ± 0.06; the effective origin varies somewhat.
-
the Comte-Bellot/Corrsin (1966)
case is representative of the better data on this flow The specificationb are given in Table I below.
recommended as Case 0371.
and is
we have assumed
In this flow (and some of the following ones)
0375A,
Note that Cases 0372A,
w2 was not measured.
V2 - w2
although
and 0375C are also essentially
decaying homogeneous isotropic turbulence. CASE 0372.
ROTATING HOMOGENEOUS TURBULENCE
The data for this flow (and those below) are not as well established as those for
"the cafe
of decaying turbulence presented above,
and more caution is needed.
As we have pointed out in
',low, the best data are those of Wigeland and Nagib (1978). tne
companion
data
these
paper,
case which
The Wigeland-Nagib
sceles.
anisotropy
contain
appears
in
For this
both
to be most
i.itensities
and
length has
free of difficulties
The calculations should le done at the three ditferent
been selected as a test case.
rotation rates given in Table 1. CASE 0373.
RETURN TO ISOTROPY
Tucker and Reynolds (1968).
Both sets of data appear rý!aionable,
TURBULENCE UNDERGOING PLANE STRAIN types of strain data in
There are two metric
for these flows
:ra given in the table.
(which are the conditions at the end of the contraction) CASE 0374.
strain.
They
are
treated
plaue strain and axisyn-
the literature: The
separately.
of
results
two
experiments
the effect of plane strain on turbulence are recommended--those of Townsend
-•
and
(1956)
but they are suffi-
The sptvc'fications
that they are hard to compare.
ciently different
of Uberoi
flow availab e--those
There are only two examples of this
on and
(1956)
406
• 2-<'. -.
.'
**..'.'. -
,-*-..-. '.'.'-
.'
.'
.
-.
. _ '-v ...--
.
-
. "•
-
.'
*..;-
.
'
-'.'-- ...
.
.--
•-.
.
-
Tucker and Reynolds (1968).
It
is suggested that both flows be computed.
The initial
data a~id strain rates are given in Table 1. CASE 0375.
TURBU!.ENCE UNDERGOING AXISYXMETRIC STRAIN
The best data on axisymmetric strain are those of Tan-atichat
(1980).
contains a number of cases of which two have been selected as disi. effects
without
inconsistency.
The strain
rate is not constant
This work
ying the desired
in these flows,
and
pddittonal data needed are given in Table 2. CASE 0376.
SHEARED TURBULENCE
Of the experiments
r
on sheared homogeneous
turbulence,
C1970)
neems to provide
(1977)
provides the only data for large shear rate.
the best data
for low shear
the one by Champagne et al.
:ate and that of Harris
et al.
REFERENCES Champagne, F. H., V. G. Harris, and S. Corrsin (1170). "Experiments on nearly homogeneous turbulent shear flow," J. Fluid Mech., 41, 81. Comte-Bellot, G., and S. Corroin (1966). '"The use of a contraction isotropy of grid-generated turbulence," J. Fluid ",ech-, 25, 657.
to improve
the
Ferziger, J. H. (1980). "Homogeneouq turbalent '!jws: a review and evaluation," Report for the 1980-81 AFOSR-HTTM-Stanford Conference on Complex Turbul.ent Flow4. Harris, V. G., J. A. H. Graham, and S. Corrain (1977). homogeneous turbulent ahear flow," J. Fluid Mech.,
"Further e/periments in nearly 81, 657.
Tan-atichat,
J. (ic'80). "Effects of axisymmetric contractions on turbulence of scales," Ph.D. Thesis, Illinois Institute of Technology. See also: Tan-atichat, J.; H. M. Nagit, and R. E. Drubka, "'Effects of axisynmetric contractions on turbulence of various scales," NASA C!, 165136, 1980.
"---IOus
Toi7nsend, Mech.
A. A. (1956). Appl. Math., 7,
"The uniforo di tortion 104.
kf homogeneous
Tucker, H. J., and A. J. ,eyo)Ids (1968). "The distortion of tional plane strain," J. Fluid Mech., 32, 657. Uberoi, J.
M. S. (1956). Acro.
,
Sci
"Effect of wind tunnel contraction
turbulencE,"
J.
turbulence by irrota-
on free stream turbulence,'
754.
Wigeland, R. A., and H. M. Nagib (1978). "Grid-genLrated turbulence with and without rotation about the strearwise direction," Fluids and Heat Transfer Report R78-1, Illinois Inst. of Tech., Chicago, IL.
L07
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Table 2 Some Additional Data for Flow 0375
Case 0375B dU/dx (sec'1)
U (M/I)
t (sec)
0
2.59
0.0000
3
3.07
0.0107
24.8
6 9 12 14 16
4.2F 6.99 12.81 17.25 19.61
3.0i92 0.0248 0.0281 0.0294 0.0305
58.4 i35 238 183 56.5
x (cm)
18
20.00
0.0315
9.6
0.0
Case 0375D
x (cm)
U (m/s)
t (sec)
AU/dx (sec-
0 3
2.04 2.43
0.0000 0.0136
7.6 19.5
6 9 12 14 18
3.36 5.51 9.88 13.37 15.57
0.0243 0.0314 0.0356 0.0373 0.0400
46.2 104 181 146 0.0
Case 0375E dU/dx (sec- 1 )
x (cm)
U (M/8)
t (sec)
0 6 9 12 14
1.73 2.06 2.96 4.57 12.04 19.40
0.0000 0.0161 0.0284 0.0368 0.0412 0.0425
6.3 19.1 36.4 102 397 308
16 18
23.73 24.29
0.0434 0.0443
107 0.0
410
.
"~~.i"i---.•--i" . .
...--
."
-----.. -.
,-.-•'..'---.'.
-.
,
. .
..-
. .
• ,.-..
.
..
.
-
.
=.
.
DISCUSS ION Flow 0370 The Conference suggested that: 1.
of the dissipation rate and/or the
Estimates
on the experimental results,
based
these various
characteristic turbulence scales,
should be
ncluded in
the specifications of
flow cases to elikminate variability in estimating these important
parameters by computors. 2.
One case of the rotating homogeneuus turbulence experiments of Wigeland and Nagib (Screen #5,
3.
u." - 6 m/s) should be included as a test case.
The experiment of Tucker and Reynolds should also be used as a test case for the return to isotropy.*
4.
The
experiment
of
(-ence
and
Mathieu
(J. Fluid
Mech. ,
1979)
should
also
be
included as a test case for plane strain. 5.
It is well accepted, based on experiments and theory, that the turbulence energy increases monotonically for the cases of strained and sheared homogeneou8 turbu-
6.
The
value
of
turbulence, Reynolds
the
exponent in for the decay of
given
number
by
J.
grid-generated
paturbulence teprtrca= rf te exponent
Ferziger,
increases
is
turbulence energy
intended
turbulence, which
S±d.
La
to
represent
is void
of
turbulence, e.g.,
turbulence
this exponent
see Wigeland and
high of
'>cumented by Comte-'Bellot and Corrsin, this
slightly with de~creasing Reynolds~ number.
non-isotropic)
isotropic
the influence
In axisymmetric
*(Ed!
(i.e.,
in homogeneous
or
is often
in
the
smaller
Nagib, or Tsuji
presence than the
(Jdoc.aan
of value
substantial given 10
upstream
by Ferziger, 7 (1955),
and
11, 10 (1956)).H 7.
........................... The proposed
for..p.ane........ numerical experiments at
......RT
< 80
using exact calculations of homo-
geneous flows are highly recommended. -4
SThis task has been done by J. H. Ferziger after the 1980 meeting and the results incorpora-ced above.] 411
VICTOIIALStOSOAM Flov 0170.
Data Inalmstori J1.Vretiler. iiaWoa4o"o.. *-&bar Voleetry or
'root ILI
root
TurbvtdSL Flea..
of Stations 16464er~d Turbulence Proflel.
r1
or
t
t.on.l 2
Ate
Case 0371
-6.0 1600
Correlot1 ion
0. C..c.-AIl.4 S.Correiao
Iow
Cas
Ygdtoe
as
turbulence.
3200 (bsd
Yoe
c$3Oae
032kpocmbLttijhomsete
"A
.
IdI.
CONTRACTIONl SET h SICTIOJI Ca"~~itl
I
T.QA R)N S"CT"O 037
.Isotropy.
sptLr
itr
M. Ub .. oI (0371A,B.C.D)
3710
(based
.1o God
gate
Too
-
T. TooVo
o.2
-
Cooitcactb.
3
-
1. Tockor A. maooLis (0113a)
C... 0374
1 L~alorood hasmF1
A. Towmid! (01;4A)
-
too
ye
T yo.
toisl..
viToa
I.Case 037S
I
Scroew
Spot-
(03)~.UC.SVan
Cose 0375
y"...-. To
-oo
yes T~
Too
-
8e:l C(r Ci l7 )
V.
-t
FI. i S ooact - Jt Go
Morri
IIIob..d4
azyofgetrie oiratood ko"Puooo.us tarhuako.. 0.14 4 o~o".
1~ae
7oesot
C-4-r Is
06-aIaem
:270 to
_o
torbalosco.
_
_
_
_
PLOT 1 CASE 0371 FILE 2
".
.
. I.
.
I
I.
S1.00
q
2
0.50
00
0.01-
0.1
0
0.2 03 ELAPSED TIME ýsec)
PLOT 1 CASE 0372A FILE 3 0.50
-
z0.10
005
0.010
0
0.02
0.04
ELAPSED TI,,.E (sec)
"413 ..
--
.
.
.
.
.
.
.
.
.
PLOT 1 CASE 0372B FILE 4
q
7,
,
,
0.50
-
0.0
0.05 I..''°
0
1
.i
0.01
0.05
0.04
0.03
0.02
ELAPSED TIME (sec)
PLOT 2 CASE 0372B FILE 4 .
1.3.Il u/v
'.
I
0
.
.
...
0.01
0.03
0.02
"" ..-
0.05
0.04
ELAPSED TIME (see)
414
1-
.
=
°,
PLOT 1 I CASE 0372C FILE 5
0.50
4
0.10
q-2
0.05
00
0.01
-
0
0.02
0.04
ELAPSED TIME (sec)
PLOT 2 CASE 0372C FILE 5
1 .2
0.
0.-
.0
00
0.-..0
---------ELAPSED TIME (see)
•
(
415 ..........................................................
Pr.I
.
.
.
.
.
-
.-
.
.
.
-
..
-
.
.
.
.
.
.
.
.
.
.-
-
PLOT 1 CASE 0373A FILE 6
0.00030
,
0.00020
F-
0.00015
0
0.05
0.1
0.15
0.2
"1
'
'
j
0.25
ELAPSED TIME (sec) PLOT 2 CASE 0373A FILE 6 0.0016 0.0015
..
0.0014
o2.oo3s
L
0.0012
L
O.1
S0.0013
L
0
o
oo
IAPE 0
0.0o1
-
...
..
ELAPED TM[E(sec) .L.o. .
416
,
.. 1
0.00035
0.00025
I
I~
0.o00o450
-4
0373B FILE 7 PLOT 1 CASE ..
•
j-
](
0.000425
0.000400 U2
o•"-
0.000375
SII 0 000350
-
0.000325L
Q 000300
0
0.01
0.04 0.02 0.03 ELAPSED TiME (sec)
0.05
PLOT 2 CASE 03733B FILE 7 !
0.0034
I0.0032 0.0030-*
0.0028
-
0.0026
0
0.01
0.02 0.03 0.04 ELAPSED TIME (sec)
0.05
417~
......................
.
I
1 CASE 0373C FiLE 8
~~~~~0.00200PLOT,,,,..
" •."
1
I
.
.
.-
'
0.0018
"-
2
0.0016-..
0.0014
H
0"
-
1
"%j
"0.0012
..
0
0 02
. ..
.. ..
0.04
.
0.06
_
_
0.08
ELAPSED TIME (sec)
PLOT 2 CASE 0373C FILE 8
0.010 0.009 v
Sv
oo 2
-i
k
0 .00 8o 0N
0.007
-
o
"0.006
0
0.02
0.04
0.06
U
0.08
ELAPSED TIME (sec)
418
.......
PLOT 1 CASE 0373D FILE 9 0.0080
II
0.0055
0.0050 0.0045
2~0.0040
'
0-0035
.-
0.0030
L
0
0.030 F
0.02
0.04 C.06 ELAPSED TIME (sec)
0.08
PLOT 2 CASE 03731) FILE 9
20.0250
*
.
0.020
0.015
0010
0
0.02
0.04
0.08
ELAPSED TIME (sec)
41
0.08
PLOT 1 CASE 0373E FILE 10 0.020
,
•
0.018
-
oao16,
:::u2
0
0,014 1-
0.012
-
0.010
0
0.05
0.)1
0.15
0.2
ELAPSED TIME (sec)
PLOT 2 CASE 0373E FILE 10 "0.007
,
oDoG
L
0.005
-
0.004
-
0.003
0
0.05
0.10.15
0.2
ELAPSED TIME (sec)
420 %''
S.- . . . , . . _-.. . , .
.....
. . . . . . . . ::::::: :: :::::: :::: ::::: ::: : ::::: ============ :: ===========
:
: . v :. 6 ":.
"
:
--. -..
" "."
-.'" . . .- .-. : .. V
,
-•?:"
~~0.016
PLOT 3 CASE 0373E FILE 10
,,,,
0.014
0
0.012
0.010
0.'-
L
0
(1.1
0.05
0,15
0 2
ELAPSED TIM.E (see)
PLOT I CASE 0374A FILE 11 .0030:
2
,
-
0.020
0.010
0.009
4
0.008
•:. n.•::.L
0
0005
'r
~
0..0
o TIME (sec)A ELAPSED ~
'-t
421
.. A,
-*Az-'-t~*
~ ~~ ft~L
-
3
PLOT 2 CASE 0374A FILE 11 0.030
-
'
I
0.025
0.020
0.010.
"S.-
0.010
I
I'
0
0.2
0.4
I
0.6
ELAPSED TIME (sec)
PLOT 3 CASE 0374A FILE 11 0.032 0
.
2 00
0.008 0.007
0006 0.005
0
0
0.05
0.15
ELAPSED TIME (sec)
F-
422
1.
[ -I
[•i
-I
PLOT 1 CASE 0374-B FILE 12 0.04
6
II
0
0.03[ 0.035"
0.02
0.000
ELA.FSED TIME (see) -.'>
PLOT 2 CASE 0374B PILE 12
...., 0.025
-
00
0.00 15
0
00
0304
.
ELAPSED lIME (sec)
k
423
-0
PLOT 3 CASE 0374B FILE 12
-I
0.030
,
-
,
I
*0
0.020 w2
'.. 0
0,10"" 0.0
0
1
".0.005
0.007 0.006
°
0•
0
0,0091
"
00
o oo
1
1
0
F
0
o
I
o
0
"
--
I
C.
.M4
0.003
0.2
0.1
0
0.4
0.3
ELAPSED TIME (see)
PLOT 1 CASE 0375A FILE 13 ,0.0040 0.0035
0o
k
' 0.0U0?
1
0
ooo•Lzcq
--
Li*"
0
.0.0025
0,0020
-.
-
0
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0.02
0.06
004
0 1
0.08
0.12
"ELAPSED TIME (see)
4
k .
.
-
-.
-"
----------
.
.
.
.. -..
PLOT 2 CASE 0375A FILE 13
=.]
v2
0 0.002
0
0.0 0 00
0.0009
U.0020 I..
0.001
I 0.003
0
0.02
0.04
0.06
008
0.1
.
ELAPSED TIME (see)
PLOT 1 CASE 0375B FILE 14
0.003
•"
1.12
-0
0.-0. 0-
O.OOE
OL
0
0.01
0.02 0.03 ELAPSED TIME (see)
425.-.
............
0.04
" ."
PLOT 2 CASE 0375B FILE 14 0.00 9
tI.1
'
0.0013 0.007
00 0.006
0.005
0.0041 0.003
0.003
0
0.01
0.02 0.03 ELAPSED TIME (see)
0.04
PLOT 1 CASE 0375C FILE 15 0.003
u0
U
0.002
0.001. 0
0.025
0.05
0.075
&.1
0.125
ELAPSED TIME (sec)
426
01
PLOT 2 CASE 0375C FILE 15
"0.0025 0.0025
-
"
"0.0020
. .I
"'
0. 0
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1433
<
TURBULENT WALL JET Flow 0260 Case3 026!, B. E.
Evaluators:
0262,
0263,
0264
and W. Podlt
Launder
SUMMAARY
SELECTION CRITERIA A wall virtue
of
jet may be defined as a thin shear
the
J.iitially
over
some
this
broad definition,
supplied the
reglu: within a
momentum,
shear
at
flow directed along a wall where, any
flow exceeds
very wide
range
of
station,
that in
the streamwise
the external phenomena
flows and
stream.
has
been well over two hundred experimental
wall jet.
Of these about one half has been prompted by heat
Within
been examined.
studies published on
There have
by
velocity
the turbulent
Iransfer considerations,
most of these cases the flow field has not been sufficiently well documented to
and in
merit close attention experiments
have
for the present purposes.
commonly
gases of different
employed
molecular
weight)
Even where detailed data exist,
sufficiently
la~ge
temperature
Among the remaining
biguous
100 or so "aerodynamsc"
relatively simple flow topography
truths
about
the turbulence
difterences
that one could not be certain that the flow
evolution was strictly independent of that of the thermal of reference precluded examination of such flows.
co those of
these
structure
(or field
or species fields; our terms
our attentiun has been given
studies,
that allowed certain intrinsic and unamto emerge--either
by direct measurement
or by inference
from the mean-flow's -volution. Within each subclass of experiments, recommendations: the following broad guidelines have shaped our (i)
good of jet,
There
should
be strong direct The
two-dimensionality.
the
two-dimensiGtal
principal
momentum
integral
compliance with the corresponding
or
indirect evidence
criterioa
applied
equation.
(For
three-dirensional
that
the
flow achieved
was
the close
the
three-dimensional
satisfaction wall
form of the momen am equation
was required.) (2)
The
flow
should be conveyed
conditions
should
he
well
by the author's documentation of
Mech. Engr. Dept., University of Manchester, Box 88, Manchester, H60 IQD, England. tSonderforschungsbereich #According
to
the
d~ftned,
80,
initial
Univnrsittt
angle
of
Inst.
Karisruhe,
incidence
and
KJ
U l. "• "2•
"-"' "2•
i
experimental
prar_-tce
-he y.'ork.
P.
of Science and Technology,
0.
D75 Karlsruhe 1, West Gcrmany.
between
the waL'
respective temperatures, the wall jet provides a highly promoting or inhibiting heat transfer rates from the wail. ,.•.4'34
g'od
effe.
and [ve
the
jet and
meanq
of
their eithec"
(3)
The experimental data should preferably
tnclude measurements of
turbulence
quantities as well as those for the mean flow. (4)
The experimental data should exhibit general credibility in comparison wi-
established results in similar flows. FLOWS SELECTED A detailed evaluation of more than fifty experimental studies is provided writers'
complete report
(Launder
and Rodi,
1980).
in the
The experimerts have been analyzed
in the following categories: (a)
The self-preserving, two-dimensional wall jet on a plane surface with or without streamwise pressure gradient.
(b)
The two-dimensional wall jet on a plane surface with an stream with zero or positive streamwise pressure gradient.
(c)
The two-dimensional wall jet developing around a circular cylinder.
(d)
The self-preserving, two-dimensional wail jet developing on a logariLhmic spiral surface. The three-dimensional wall jet developing in stagnant surroundings on
(e)
external
I:
a plane surface. There follows
a brief discussion of the experiments within each of these catego-
Nomenclature
ries.
relating to the two-dimensional wall jet is shown in Fig.
the three-dimensional wall jet in Fig. a.
Case 0261. Within
2.
Self-Preserving 2D Wall Jet on Plane Surface
this flow category the great majority of studies have considered only the
case where the streamwise pressure gradient is rest. of
zero and thus the external fluid is
Fifteen such studies have been scrutinized,
Bradshaw
Guitton
and
and
some
Gee
Newman
two-dimensional begins
1 and to
(1960),
(1977),
momentum
Patel and
Verhuff
integral
50 slot heights
(1Q62),
and,
Tailland
(1970)
equation.
downstream of the
show In
of these, (1967,
the
only the experiments
1970),
satisfactory
Guitton
(1970),
compliance with the
self-preserving
exit slot,
at
region,
the rate of growth
which of the
half-width is constant and given by dYl1/2
"
0.073 ± 0.002
dxIt
is
(1)
worth noting that the half-width grows over 30% less than in the plane,
in still
air (Rodi,
Wide The direct display
1975).
variations exist
in
the values reported
force measurements of Alcaraz
a variation
free-jet
that
is
in
(1977)
excellent
for the skin-friction coefficient.
appear the most reliable and further
accord
with the
earlier
recommendation
of
Bradshaw and Gee (1960): Cf
0.0315 Re
0 18 2
(2)
435
.
--
I."
. .
"
--
.
.
.
.
.
.:'-
: ::.
,-
"
71!
_
where 2 -w Cf
UmYm
and
-U
Re= m
U2
f
mm v
None of the turbulence data for this case of stagnant factory,
due principally to the very high percentage
edge and to the steep velocity Wilson (1970) and those
show
entirely satis--
fluctuation levels near the outer
gradients near the wall.
Those of Guitton (1970)
and
the best agreement between directly measured turhulecut shear stress
inferred
from the momentum equation.
the studies of Giles et al. Wilson (1970)
surroundings is
(1966),
There
Guitton (1970),
is
reasonable agreement
Taslland and Mathicu (1967),
for the streamwise normal stress measured with a normal wire.
also obtained this component from his slant wires, stress are substantially
different.
This
among
however,
Tailland
and the values
discovery cannot
help but
and
for normal
raise doubts on
the accuracy of all the data. The case of an equilibrium u-
jet in an adverse pressure gradient has been stu-
died in three sequential studies at McGJll University, Those of Gartshore and Newman (1969) and Irwin (1974) achieve satisfactory momentum balances and, while the former examines
three
different
ratios of U :U-
the
for a velocity
ratio of
2.65:1,
a complete
measured Reynolds-stress duces
the turbulence
including
profiles.
intensities
(The
latter provides a
presence
of
and thus greatly
and consistent set of directly the moving external
improves
these experiments
stream re-
the accuracy of the hot-
wire data in comparison with the case of stagnant surroundings.) fore,
very detailed study
Collectively,
there-
provide a searching combination of breadth and detail against
which to test the capabilities of flow calculation procedures. b.
Plane 2D Non-Similar Wall Jets on a Plane Surface (No
not
test case)
We consider first the case of a uniform-velocity
external stream.
a
downstream,
self-preserving one,
progressively
diminishes.
for,
as
the
(Ultimately
shear flow eventually change
jet develops
and Rodi
(1980)
examined some 15 studies of
tial conditions were not adequately
and Kruka and Eskiuazi
feel that bilities 1980)
formal
test
(1964)
case is
this class of flow.
reported.
point of view of momentum balance were No
and the
into a normal turbulent boundary layer; usually the test
are too short to allow this development to be documented,
0.263.)
ratio of U:UE
the velocity maximum would disappear
sections
(1967),
the
This flow is
however.)
In most cases,
The most satisfactory
those of Gartshore
Launder
and Newman
ini-
cases from the (1969),
Nicoll
(the last-named only for values of UE/UI up to
proposed
for this
we
pri
some of the other cases will test more sea'chingly and precise!% of any calculation
proceduce.
Nevertheless,
our survey
.a-.
(Launder and Rodi,
has shown that the flows exhibiting reasonable conformity with the 2D momentum
436
.+
' .-
• .
-' - *.
, ',
' ,
.
,- ',
*
•
+ ,.-. . •.
.-
,
.,
.
LA integral
equation
where
is
x0
wall
the
the
display
a
nearly
vIrtual origin
*
For
jet.
mental scatter,
(x
and Yl/
/0
is
universal the
x )/0
2
of
flow
the
in
dependence
and
range
is
vide a straightforward
test which for
tive to the details of
the initial
boundary in
tangential layer
several
injection
developing
aeronautical
flows,
two-dimensionality
ent;
the
flows
moreover,
their
flow
Irwin
(1974)
dictive enough
Leveral
provide
8-70,
the
variation
to absorb
a dangerously layer.
Two
experiments
as
a test
calculation
procedure
Case 0262.
X
-
of
experi-
within
values of U /U"E would
of
to
five
to
than
region
competition
midway betwen flows
turbulent
is
important
the
boundary In
layers.
zero
these
pressure
this
type
cases
for
flux of
while
of
a
sukf icient
of
different
layer,
from oti-er
in
provide
injected momentum boundary
gradient
boundary
developments
and interestingly
low velocity
gradi-
details
of
examined
by
testing
the wall jet is
for Case
prelarge
C the shear
the wall and the edge
difficult
flow
of
precludes our nominating
they certainly provide a searchingly
case,
be insensi-
beneath
separation
"blown"
failed
flow
fluid
pressure
to maintain
have
the
of
prevent
to as
referred
the
stream
"ad,.rse") is
aim
the initial
Although
(or
more difficult
For his Case B,
boundary
c.
The
e)periwenters
entirely
is
(x
thickness
xo)/9
initial
a high-velocity
satisfactory
develops
on
of computations with this line would pro-
large
a positive
is
conditions.
schemes.
in
of
are sometimes
and
/0)
conditions.
flows.
layer,
2
local momentum
described by:
our view that the degree of compliance
The
(yl/
the
Yl/2/0 - 0.03 + 0.033(x -
It
of
6 is
the
these
test of any
for turbulent boundary layers.
2D Wall Jet on a Cylinder
(not used in
1981 meeting)
The two-dimensional wall jet developing over a convex surface has proved to be a very difficult flow to establish, due to the tendency fur .rall spanwise irregularities
to
encroach Alcaraz
on
(1977)
and
whole and
Alcaraz'
blunt
experiment
study with one
exit
of
Penerallv the
gradient
flow.
Of
of
Fekete's
one
streamwiee
for
pressure
t•io-dimensionality.
machined
but
the
and
downstream
acceleration
radial
quate
amplify
the
provides
and
slot
configurations features of heights
triple
less
by the
of
studies analyzed,
(1963)
achieved
the apparatus than
1%
of
moments.
As
of all only
imbalance
end
the
only
of to
walls, that
demonstrably
of
ade-
design are careful]y the
the most complete available documentation
rnnsistent meacurements
active
vicinity
the
six experimental
Two crucial
slots
in
,
dri.
vortices,
cylinder
radius.
of any wall-jet
non-zero Reynolds stresses and all the
first
20
degrees
of
arc
are
who suggested that the momentum This is an adaptation of a proposal of Patel (1970), thickness at the slot exit should everywhere be used for the normalization. 437
4
the
however,
considered, in
about
2200
however,
the wall
uxperi-
to separation
from discharge
At this positiun
station.
(at
with progress the departurc
jet is
about twine
which underlines
on a plane surface,
for the same distance
as thick as one developed
Fekute's
mild.
for the smallest value of b/R* (0.0074),
up to the 1450
not serious
relatively
steadily deterioratos
The flow two-dimensionality
of arc).
around the cylinder; is
are
curvature
of
the wall-jet development
document
contrast,
ments,
effects
the great sensitivity of this flow to the additional strain imposed by curvature.
subject
ot
careful
two
studies
Lhe Inside of a cylinder
around
"iný rase vf wall-jet uevelopme.
(Guitton,
neither case have the data been reported
Spettel
1964;
al. ,
et
hag formed
1972),
though
-
the in
in sufficient detail to allow us to recommend
their use as a test flow. 2D Wall Jet on Logarithmic Spiral Surfaces
Case 0263.
d.
When a wall jet is
jet thickness increases at the same rate as R.
the of
developed over a logarithmic
flow curvature
self-preserving fact,
and,
form.
indeed,
the same
remains
and
the
flow attains a tnis
Four care-
flow for spirals of varying degrees of tight-
Each has included the plane surface as a limiting member of the class of flows
1977)
Neu-an, reducing
has worked hardest at (and appears to have been the most successful in)
secondary
flows;
thus,
exhibit a slightly smaller et al.
dependence of
(1966), /
and Kamemoto
spread
than
(1974),
we
S0.073
judge
(1962),
them to be more reliable.
The
+
-
l 2
0.3(yl
(3)
2R
R * =, to the recommended plane-surface spreading rate.
in the case of
undergoes
shape as the value of K is
increased,
velocity
suggested by those of Sawyer
is well described by the formula:
profile
The mean
given value of K his two exper±.nents
for a
although
rate of
Y1/2/×8 which reduces,
see also Guitton and
Guitton (1970;
thus providing a valuabla cross check.
examined,
Giles
K,
the non-dimensional strength
thesis provided the first experimental data.
his Ph.D.
x/R
to have been the first to recognizo
appears
ful studies have now neen made of this ness.
Thus,
to station,
from station
Sawyer (!962)
spral surface where
cinity of the velocity maximum.
a
small
but
consistently
reproduced
becoming less pointed--more
A quantitative
change
of
rounded--in the vi-
manifestation of this is
that ym/Yl/2
increases with K being well correlated by ym/Yl2
- 0.159 + 0.205 Yl/
a relation proposed by Kamemoto (1974). skin-friction coefficient is
2
/R
(4)
There appears to be no firm evidence that the
significantly affected by the level of K.
R denotes radius of curvature of the surface (in
this case the cylinder radius). ",.1
438 At.0
'
•*
"/
-1
4
Guitton's stresses
(1970)
measured
expe.r inent-R
also
by hot wire which generally
ity from station
to station.
f.
exhibit
(aR
set
they should)
of
Reynolds
close similar-
Case 0264.
Plane 3D Wall Jet in
as
elsewhere,
discharged other than detailed
jets
discharged
satisfactory
by the momentum inte-
turbulent shear stress showed it
to be within
that
have
of
the
(or
the wall
Launder and Rodi
square),
At
the
circular,
jet has been (1980)
nozzle and
provide
exits
momentum
the
on
however,
The shear
to
balance
semi-circular
both
made;
be
flow exhibits a behavior in
about is
wise increase of yl/
the
quantities
exhibit
take
on a
(1972)
self-preserving
indicates
character
the
good agreement
highly unequal rates
awong
the various
of spread
experiments
Greater variation exists
ditions.
in
the y and z
about
the stream.•
ters downstream
in
are
uncertainties
k probably falls
of
the most (1974)
dz
the
which extended ooreover,
asymptotic
2
u 2 /U
found
that
symmetry
plane
this
quantity
to 200 nozzle diame-
one of
the
two cases
lateral
exam-
Having regard
rate of
growth
0.26 ± 0.02
turbulence data are available in
have
believe
motion to fully developed con-
\ery .
*
dx
(1972)
a feature we
1/2-"
F--1/
the
spreading rates,
obtained effectively the same value.
within the band:
No eytensive sets of
(1972)
reliable;
interpretation,
P
al.
lateral
of Newman et al.
ined by Rajaratnam and Pani the
the reported
probably
(5)
0.048 ± 0.003
-
to the slower approach of the lateral
The experiments
in
the data being bracketed by:
-d-
is
shows
A
The most
dy1 1 2
due
A
the near
uniform and the velocity maximum decays as x -1 flow is
, all
2
the exploration by Newman et al.
turbulence
spread is
There
to be largely
the
strongly on the shape of the nozzle and the exit flow conditions. been thoroughly defined ip any of the studies considered. Beyond
flow and
feature
directions.
studies where
investigations.
rectangular
this respect.
r4.
the rate of
striking
sets of
check
a
100 slot-exit widths,
which
considered
to the test plate.
five
from
to allow
behavior in
the mean
not
working medium has included both air and water. Only two studies 1972; RaJaratnam and Pani, 1974) have reported their measureaients s11f-
field that depends and these have not about
we
variously
fully
ficiently
et
4
Stagnant Surroundings
tangentially
examination
holes, and the (Newman et al.,
for
-
20% near the position of maximum stress.
Here,
a
comprehensive
a
A check of the agreement suggested
gral equation with the directly measured about
provide
similar for levels
about
(6) the far-field region, x/b greater
than
50% greater
*
but Newman
110 and that on
than
for
Guitton's
data of the plane two-dimensional wall jet.
43-
439
" i
.•I•-
RECOMMENDATlONS Under died.
the general heading
Despite
experiments closure
emphasizus useful
the
will
McGi!l
"wall Jet,"
serve
to
it
provide difltcult
Overall,
a wide
difficulties,
Certainly,
(those
our view
tha.
incontrovertible
nnd
several
tests of
of
these
turbulencein
Thii.4
effort evolving over a decade or more.
read
of
before anyone e~nbarks on further
through
Fekete,
Lhe
collected
reports
Gartshore,
Guitton,
the
two-dimensional
flows,
th. distributions of v
jet in
stagnant
tive.
As
part of
tation
of
these
to lessen
surroundings. a wider
of
mic
less
surface
was
it
the
the study of than
to
brief
be
now
jet,
he
group
at
himself
irksome
gap
in
on
the
our knowledge
the "simplest" case--that of
in
might
high-intensity in
the most
Several data sets exist,
using
dimensionality achieved spiral
2
etc.)
wall
Newman's
and patience can overcome them.
perhaps
aud w
study,
quantities
problems
2
stadies cf t'e
from Professor
Irwin,
problems that may arise and the way that skill
that of
is
flows has been stu-
how crucial design and experimental technique have been to obtaining 1eally
should
For
spectrum of
the most successful studies have been those undertaken
that have made a large-scale
data.
she)
of
experimental
proposals.
laboratories
(or
FGa FUTURE WORK
to obtain
available
a detailed
laser-Doppler
turbulence.
Although
Cuitton (1970)
of the wall
desirable,
we
feel
the plnite wall
but none can b- called defini-
possible
wJdely
is
that
it
the
degree
Jet on
documen-
anemometer of
two-
a logarith-
would be very difficult
for any further study to do better. Future cases.
etfort may,
in
our view,
The very rapid lateral
developing on a plane surface the
anisotropy
of
the
be moqt
rate of spread in
Reynolds
fruitfully
directed
(dzl/
found
2 /dx)
stagnant
surroundings arises,
stresses
acting
in
the
to obtain an rations
in
plane
direction which acts as a source of streamwise vorticity.
It
to three-dimensional
for the case of the jet large measure,
normal
also
include
the relative spreading rates
the way in
that
the
presence
of an
directions normal and parallel
the
stream
would be very worthwhile
accurate documentation of the profiles of these stresses.
should
to
from
Further explo-
external
stream affects
to the surface.
REFERENCES Alcaraz, E. (1977). "Contribution a l'tude d'une paroi convexe A faible courbure," Lyon. Bradshaw, P., stream,":
d'un jet plan turbulent 6voluant le long Thse d'Etat, Universit: Claude Bernard,
and M. T. Gee (1960). "Turbulent wall 1RC Reports and Memoranda, No. 3252.
jets with and without an external
Fekete, G. I. (1963). "Coanda flow in a 2-D wall jet on the outside cylinder," McGill University, Mech. Engr. Dept. Report No. 63-11. Cartshore, I., and B. G. Newman (1969). "The sure gradient," Aero. Quart., 20, 25.
turbulent wall
Giles, J. A., A. P. Hays, and R. A. Sawyer (1966). mic spiral surfaces," Aero. Quart., 17, 201. 440 *1.J
jet in
"TurbuletL -.. i1
of a
circular
an arbitrary presjets on logarith-
J
Guitton, D. E. (1964). "2-D turbulent wall jets over curved auifaccu," Mc~ill University. Mech. Engr. Report No. 64-7. Cuitton, 1). E. (1970). "Some contribut~iG,... to thc study of equilibrium and nonequilibrium wall jets over curved surfaces," Ph.D. thesis, McGill Univers.ity, Mont real. Cisitton, D. E., and B. G. Newman (1977). "SeIf -preserving turbulent wall convex surfaces," J. Fluid Mech.,8 155.
jets over
IriH .A .(1974). "esrmnsin blown boundary layers and the~r prediction by Reynolds 'stress modelling," Ph.D. Thesis, McGill University, Montreal. fr~amemoto, 7*surfaces.
K. (1974). "Investigation of turbulent wall jets over logarithmic spiral (1) Development of jets and similarity of velocity profile; (2) Properties of flow near the wall," Bulletin JSME, 17, 333. 20, 555.
Launder, B. E., and W. Rodi (19.80). "The turbulent wall jet--a review of the experimental data,' report commis 3 ioned for AYOSR/HTTM-Stanford Conference on Complex Turbulent Flows, September 1980 (to appear in Progress in the Aerospace Sciences, 1981).
4
'
Newman, B.G., R. P. Patel, S. B. Savage, and H. K. Tjio (1972). "Thr~ee-dimiensional wall Jet originatin'g from a circular orifice," Aero. Q~uart., 23 187. Nicoll, W. B. (1967). *'The turbulent wall jet: its effectiveness," Ph.D. Thesis, Urniversity of London.
development
and
film cooling
Patel, R. P. (1962). "Self -preserving, 2-u turbulent jets and wall jets in a mo':ing stream," M.Eng. thesis, Dept. of Mech. Engr., McGill University, Montreal. Patel, R. P. (1970). "A study of two-dimensional symmetric and asymmetric turbulent shear flows," Ph.D. Thesis, McGill University, Montreal. Rajaratnam, N., and B. S. Pani (1974). ASCE., Hydraulics Div. (HYI), 69. "Free turbulent Rodi, W. (1975). Studies in Convection, 1, 79.
sh.ear
Sawyer, R. A. (1962). "Two-dimensional Ph.D. Thesis, Cambridge U'niversity.
The-dimensional flows--a
review of
turbulent
jets
turbulent wall
jets,"
J.
the experimental data,"
with
adjacent
boundaries,'
Sridhar, 1<., and P. K. C. Tu (1969). "Experimental investigation of curvature effects on turbulent wall jets," Aeronaut. iou., 73 977-981. IRS,
'Tensions de Reynolds et production Spettel, F., J. 'Mathieu, and J. Brison (1972). d'gnergie cin~tique turbulente dans les jets parietaux sur parois planes et concaves," Journal de M4canique, 11, 403. Tailland, A., and J3.'M-athiau (1967).
"Jet parietal," Journal de M.6canigue, 6, 103.
Tailland, A. (1970). "Contribution a l'dtude d'un jet plan dirig6 tangentiellement a une paroi plane," Le Grade de Docteur des Sciences, Univ. de Lynn, No. 618. Verhoff, A. (1970). "Steady and pulsating 2-D stream," Princeton Un~versity Rept. No. 273. Wilson, D. J. (1970).
turbulent wall
jets
in a uniform
Ph.D. Thesis, Mech. Engr. Dept., University of Minnesota.
441
C
.
UL
11/2 AU,.
yi Y.V{
-
I
U
1 J.
uU.
Figure 1.
'.
The plane wall jet: configuration and nomenclature for Gases 0261 and 0263.
4421
5,.-
/2 AU
DISCUSSION Flow 0260 I.
It
should
were
based
tion of
the initial Jets
pointed
on
the
out
that
check of the
the momentum balance.
similarity
2.
be
within
the
two-dimensionalLty The
the experimental
cases meeting uncertainty,
conditions at the jet-nozzle
lip
is
sharp,
wall
experiments
nozzle exhibit must less sensitivity.
443
of
the
these
and are
Launder
flow and
criteria therefore
and
Rodi
the satisfac-
exhibited
self-
irsensitive to
exit.
on curved surfaces are often sensitive
jet-nozzle
used by
criteria
selection
to the initial
conditions.
with
trailing
a
blunt
edge
When of
the the
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSTBLE Casae 00261.;
13.
Data Evraluators:
Data Takers:
Launder and W. Rodi
Various--Correlations PICTOAIAI. SUMMAIT
*w.b.f of StetLR
C4.. Oct. ?"atf C...
dp/do .r
Test Rig (.try
Io.f*d halv
t
2
2
Ot.
0261
Wsrl.. "t.
take.
To*
)0
tick C-d4i tio
or
C,
Yeei T.0
1 7
*
.
6
I
L&
~
4-1tr 0
C.- .
Other Notes £.1Ikt
to1 10or
.4..
Trile. bl.eA
Plot
Ordinate
Abscissa
Range/Position
I
dy 1 /2 /dx
UE/U M
0 < UE/Um < 0.8
Sec Instruction 3 below.
dyM/dx
UE/U M
0
See Instivuction 3 below.
2
0.8
Comments
U UE 3 4
0 _
UE /'Um . 0.38.
Y"/'1/Z
0
UE/Um
Y/Y1 1 2
0 ( Y/i* <
11 UM
>">12 /12EU
0 < Yy/1 .2 <2.5
UEU
-
0.38.
Y/U1F ""/2
0 < Y/Y1,,2 (2.0
L! /Uw
=
0.38.
0
Y/y1/
2.0
U F /Um-
0.38.
UE /m
0.38.
0
I j/y
2.0
Y/y1 /2
Y/y1 /' 2
0
Y/y1y 2 K2.0
/y/
-
'aQ/(u UEU)
2
-
0.38.
2% 1/2
5 SLU
15
0.38.
m E 1/2 6
-U
U M
E
2 (W)
7
8
3 -U
j/Y1/2
UE)12
9v -
10
V -
(Ur
U
j
E
2
UE) 4~44
UE/Um
-0.38.
al
Jt g4.
.
Plot
Ordinate
Abscissa
Range/Position
Comments
3.5 < logl
11
Cf
0
logo 0
MyM-)
lcgl
0
( m M
See Instruction 4 below.
S4.5
U -O.
Special Instructions: I of Summary,
is defined )n Fig.
Flow 0260.
1.
Nomenclature
2.
This test case considers The family nf equilibrium wall jets on a plane surface in which
the frze-stream velocity
is adjusted to keep the ratio of free strcam:maximum veloc-
dienL whose magnitude ity invariant
iz retarded bj an adverse streamwise pressure gra-
with x.
Patel
and
Newman
(1961)
have demonstrated that
the above
conditions are met when (x + xo )m[1]
UE
where xO
is
the e fective origin of the flow and -0.5
explorations
Computors
"UE/Um
r',lch
should calculaLe
between
The range of
is to include the wall jet in a stationary medium which is a limiting
case of this family (for 3.
< m < -1/3
UE/Um
-
0
and
dp/dx - 0 ).
the wall-jet development
zero and 0.8,
for at
least
including the values 0 and 0.38.
weak effect of Reynoldn number on the flow,
five values
There
is
of
A (very)
and computors should ensure that the
Reynolds number based upon the maximum velocity (UmYm/V)
lies in the range 4 x 103
to 5 c 104, which corresponds approximately to that of the experimental data. For
each set
flow conditions,
Plot
at
the
jet
Gartshore
and
figures.
Newman
x
=
0 ,
with an
self-similarity
is
1(Plot ) and y. (Plot 2) versus
The figure already and the value
(1969),
e. t,
until
computations
the computed linear growth of
UE/Um on the accompaiying (1973),
start
Continue
profile.
initial
appropriate achieved.
of
contains
for the wall
values by
Irwin
jet in stagnant
surroundings recommended in the survey by Laundcr and Rodi (1980). 4.
For
the
friction
case
where
the external
coefficient
cf(•
•w/
stream is I/
2
at
pU ) should
rest,
calculated
be compared
with
values of the
skin-
proposal
of
Bradshaw and Gee (1960j: UY U cf
References
-0.182 [21 (--
0.0315
(see also summary)
Irwin, H. P. A. H. (1973). "Measurement in a self-preserving plane wall jet in a positive gradient," J. Fluid Mech., 61 33. Patel, R. P., and B. G. Newman (1961). ing stream," Report AES, Mech. Engr.
"Self-preserving jets and wall jets in a movDept., McGill University, Montreal. 445
CASE 0261 PLOT 1 0.08 L
00
004-
U.02
0.0 Oý. 0
0.2
0.4 UE/UJ
0.6
0.68
-6 P'OT2 C 21 0.025
0.020 dy./dx
0015
0.010
-
00
0
02
0.4
0.6
0.6
uz /Um
446
.
-----
.
. ...... ....
CASE 0261 PLOT 3 1.0
00o
o .o0
0
0 0.8
I,
I
0
[
0.6 '
0
U-U/Uw-U 0
0 .4
4
I0
10
0.2
0
0
0.0
0
Lj
I
0
0.5
2
1.5
1 Y/Y I,'2
CASE 0261 PLOT 4
SI 0-015
-
i
i
0
-
S0
0 0 0
0.010 S0
0.010
-
0"
0
0
0
2 Uv/(U -UE) 2
o
0.005
0
0
-
0000
-'0
000
-0.Q005
~0'.
0
0
0.
o'
-
¢,
0
o
0.5
1 Y Yl~ ,/2"
1.
2.
447
I:=:
CASE 0261 PLOT 5 o.20
200
--
''
,
0 00
0.15
S0
0
0000
00
0
I
o0
I
0j 0
0.10
'
0
00 0.00
40
05
0
00
0
.
----------
0.00
0
O"
.
0-
• :
0
..
Y1,"
/Y48
* "'
0
0.
o 1.5
1
2
Z. 5"
•,
0
0
00
g-
0.05
0_
•'''
0
0
•o .:coo
_ _ _..
0.:
O0<.
. . . . ..
o5
.
1
.5
2
l
2.5
448"
_,.v ","~~~...... . . ..
. . ...... .. ....
.......
"
."
... 7.-.-"..
-
.-.
.2',
-
CASE 0261 PLOT 7 IF 1
0
0,
0
0.15
o-
0
00
°
0.05
-]
0.0
0 0'3
0.3
1
2
.5
0.003
:
0i
0
00
0
0.0
0
0
0
.
0
I
0.000
Y/Y
0
CASE
-0.001,
0261*PLOT
1/
8
. .o
.
.
.
0
0.5
1
.
1.i5
449
.
2
.
-
PLOT 9 CASE 0261 L
.00 010
o *
0
0
0
0
0 0
0
0
I000
"%"
0
0.0000
0
co•
UV)3 _0ooo I.
0"
u• -o'".
-
-
0
*0
V
~-0,0005
-0.0005
0261 PLO 10CASE 0o
-
0
0
0
PO
0
2
00" 0 CAE00
0
/
0•0000 0
-0.0004
03
3
0.0002"-
0.0000
"
0
o
"
0
e
000
450 450
-
-0..
A
"(
.
PLOT 11 CASE 0261
-2.15F
lo
0 0
F
0 .2IJ
000
00000
0000.
-22.25il~Y
4.5
I3.537
451
%..
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case 00263;
Data Evaluator-:
Data Takers:
floore 060.
D.
W411 Jet.ý
Station. Measured
bor of
T-rtlau 1 1..
Pr0(o11f1 . t
dp/dna
V
C--
V
try
Newman
.ld. "I~~r+• 'Turbule~t
Dot& 9.41Le-~tl
VILEicy
G
Launder and W. Rodi
Guitton and B.
c
bete Taler
B.
7-105
o_._.It
Note:
r
5411-preairvie4 wall jet m loglrithotc spiral
CA"41026) ye.
CI
to
K
To.
Plot
Ordinate
Abscissa
1
YI/2/x
Yl/2/R
0 < y 1 / 2 /R
< 0.3
See Instruction 2.
2
•1ov/U2
y/yl/
2
0
2
< 2.0
See Instruction 3; K -
2/3.
3
u2/U2
y/yl/
2
0
2
< 2.0
See instruction 3; K
2/3.
4
v 2 /U2
y/yl/
2
0
2
< 1.2
See
5
2k/Um
Range/Position
Comments
-
Instruction 3; K a 2/3.
2-
Y/Yl/2
L
0
< 1.1
2
See Instructionj3; 2
2k ou
+ v
2
+w
2
K - 2/3.
.
Special Instructions: 1.
Nomenclature shown on Fig.
2.
Computations
should
over logarithmic of
K in
along
the
the wall
ture R is tations
be made
surface
zero).
should
of
the
spiral surfaces
range 0-1.2,
extend
development
(x/R
including
K,
-
is
until
of
the
2/3.
origin
(i.e.,
the
wall
jet
three values x is
radius
moasured of curva-
confined to the self-preserving state so that computhe
normalized
profiles
of
plotting
Yl/
versus
at least
where
The dependence of the growth rate of the wall /x
for
The coordinate
change.
2
two-dimensional
a constant)
the value
from the virtual
Interest
Flow 0260.
1 if Summary above,
y1 /2 /R and comparing
flow variables
cease
to
jet should be displayed by
the calculated
behavior with
Plot I;
this plot displays the equation: 452
AN1
-'.
S*• "r•
....
..
.•-'-• -"-
. .
-=•"+"•-• , ,
. .
''•; +'+
. ,..
. . . .. -o.. .
L'
•'-
..
""
. . .. .•.
""
..
" .
.
....
•" .
.
'"
.
.
'
.
"
..
....
-
.
'
+,
"
.-
.
.
- "
""
,
-. "
-•.
Yl/2/xwhich
fits
the experimental
though no
arrange
3.
0.073 + 0.8y 1 21 /R
Reynolds-number
that
data of Guitton
dependence
the Reynolds
number,
is
0.3(yl 1 2 /R)2
-
and Newman
discernible
U Y•/v,
in
in
(1977;
see Summary).
the data,
computors
the asymptotic region lies
Alshould
in
the
range 7 x 10
-
For
detailed comparisons should be made with the Guitton-Newman results,
K -
2/3,
5 x 104.
of which
the profiles averaged over the final three measuring
vided on
the
of
normalized
method,
accompanying graphs. Reynolds
shear__stress,
stresses u 2 /U 2 ,
the normal
Compare
calculated
mV/U2 and,
v 2 /U.,
and 2k/U
if 2
and measured provided
.
stations are pro-
(k
by
denoting
distributions
the the
calculation turbulence
kinetic energy.)
. 1
PLOT 1 CASE 0263 0.3 0 I
0 0
0.20
0.2
I k
0
o
-ji
0
Y 1/x 1
0
1
0
0
0.1" 00
0
0
y
R 0.2
453
i..
.*. .. ... .-
. ...
. . . . . .
- 4 l. m
_
0.3
PLOT 2 CASE 0263 0.03
0.02-
TV / U.
0
0.01 Loo
000
N
0
o 0
~/0 -
i~ 1
00 Lo
oW
00
0
0
*
00
0 0
0
00.0%
0
00 0 0
0
Y/YI/2 00
PLOT 3 CASE 0263
0.06
00o
7U U.
o-
0 04
.
,-
0.0
%00
-
1 0
0.06
o
0
1
-
-0
CE2 oo0 0
0
0
00
0.00
: ..: : -2:--. .'2-.:-..-:-.'-:'.:-:< .: .. :-:..> .: .
,....
Y/Y'/2 . ,.._
--
454
A4
:
.. _:.
.
:.•
- .
.
.
::0
PLOT 4 CASE 0263 L 0 .0
I
4
90%0. Oo
0.04
.
0
0
0
4
00
0
0.02
°
0o
0.000.
,
°
"
0
0
0.5
0
Y/Y /
PLOT 5 CASE 0263
0.13
o
..4.
00
o 0 I0
*0
:.
00
0
--
0
0.14
00
0,1-.__ 0
2k/U2
0
___
1
o05
0
.°
._
_
__
_
_..Ii
...
0 0,5
0
Y/I/
.
.
.
.
4551
0
.
- .
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case 10264;
Data Evaluators: Data Takers: PICTUIIAL
Timw 120.
B. Launder and W. Rodi Various
0H~OWA5
Date Ivalvatorsi 1. LAns
end W. todf.
N.ssbr of Station.
Th~.dli.nc.
Velocity
o
Test 1111r O~swetry
_______-I Dun~ To"r
Profleas
~
Cý,
well Je.*.
-Turtwlen
Iw..er..
I.e
Ohr
I 00
cos. 02" Voris"e llt&Talr
y.fL~s*ree
o
-
To$
Plot
te
ID t..i1 '.t1. still sir
Ordinate
Absc~issa
0
10
Range/Position
le
t X
o.WPo.' plot.
rajotred.
CommentCs
For this case, no plots are needed.
Output
consists of constants; gee comments below. Special Instructions: I.
The flow configuration and the nomenclature are Flow 0260.
Sufficiently far from the nozzle exit,
and independent of the exact exit conditions. spreads
shown in Fig. 2 of
linearly both normal to
the wall and
dy 1 1 2 /dx and dz 1 1 2 /dx are constant; Computors
the Summary,
the flow becomes self-similar
In this similarity region, the jet in
the spanwise direction, so that
further U. decays approximately as x'.
should calculate the spreading rates dyl/ 2 /dx and dzl/ 2 /dx for the
self-preserving
state and compare them with the measured values recommended by the
survey by Launder-Rodl (1980): dy12dz O.
1/2 X
dx
Equatioa
(11
corresponds
Although
no
clear
closely
to
Reynolds-number
-02
1
the measurements effect
was
of
discerned
Newman in
et the
al.
(1972).
experiments,
computors should make the calculatione with a slot Reynolds number Umb/v of 10~ or greater.
The nozzle shape should have no influence on the self-preserving
but the recommendation to computors
state,
Is to consider the jet issuing from a square
nozzle as shown in Fig. 2 of the Summary, Flow 0260. Computors way solve either theelf-preserving form of the equations (in which prprisaea~mdto be functiono' only of (y/x) and (z/x) or march in the stream direction until a selfpreserving state is reached. 456
SESSION Ix
Chairman:
S- Bogdonoff
Technical Recorders:
IP.
Ebc T. Morel
Flow 8610 Flow 8630 Flow 8640 Flow 8680
457
COMPRESSIBLE FLOWS OVER UEFLECTED SURFACES Flows 8610, Caseg 8611,
8612,
8630,
8640
8631,
8632,
M. W. Rubesin* and C.
Evaluators:
8641 Horstman*
C.
SUMMARY
SELECTION CRITERIA AND FLOWS SELECTED The experiments from
ing
the
treated of
interaction
in
fully
in
test surface
itself.
Settles et al.
(1979);
computor,
and
specifications
will
be
selected
in the
as
Bachalo and Johnson
and Settles et al.
(1976);
for presenting
given
result-
shock or expansion
with
(1980);
this summary each of these experiments will be described
In
flow fields
by
The experiments
Dussauge and Gaviglio
detail in
Delery and Le Diuzet
(1979);
layers
boundary
turbulert
waves generated by the shape of the test cases are reported
characterized
this summary are
view of output
(1980).
the needs of a of
tht
computa-
tions. improvements in
Even the best of these experimento cannot be used to guide
of
performance models.
important
systems suffer of
the
air
of
better
prediction of
on the
and
Another
layers.
for
account
from seeding response
frequency
pre-existing
The
density
than ± 5% to ± 15%.
the
reduction
turbulent
for complex
the existing
in
fields
compressible
is
the
hot-wire and
fluctuations,
LDV
The high speeds
sensing systems.
It
has
local flucttlatimportance
requires an assess-
flows
schemes;
turbulence modeling and computational
within the
of
th? technological
Nonetheless,
turbulence
reason
nonuniformities. of
overall
they axe conducted within
that
measurements.
to
the
assessing
none of the experiments can provide measurement of
that
ing quantities
ment
assumptiorns
of
to preclude measurements
boundary
compressible-flow
burden
been estimated
of
the
of
is
limited
that are so small as
from small windows
adds a
are
means
a
and sp3cif!c,
methods
experiments
additional
requires
provide
however,
buffer-layers
and
inaccuracies
greater data
these
flow facilities
sub-
do,
computational
particular reason
One
compressibl.e
They
models.
lence-closure
turbu-
the data
selected
can serve this purpoee. Selection of the
configuration
was conducted; had
to
have
a
and
each
particular the
studied;
expertment
largczt
range
the basis
was made on of
the variety and number of quality data.
well-defined
the two-dimensionality
had
*NASA-Ames Research Center,
flow: to
be
e.g., well
Moffett Field,
if
nominally
a
CA
of
the experiment
To qualify,
the Experiment
two-dimensional
The
documented.
uniqueness
which
over
variables
of:
accuracy
of
expeLiment, the
relecte.'
94035.
458
L :i ,.
.
.-
- - . -
• : "
-. i-- .
---
--. i
-:
:
. '
""
-
-"
"."
" ..
. ."
'
"
" "
experiments was estimated from these sources: (1) similar experiments; of
the
accuracies
(2)
of
the experimenters'
particular
comparing the results
th dota from
own estimates of accuracy;
instrumentation
based
on
the
(3)
a judgment
eval-jator's
experience
with similar instrumentation. Cases 8611 A
8612.
bump
produces
on
Trdnsonic Flows Over an Axisymmetric Bump and Two-D.mensional
the
surface
ai acceleration
of
ciently high Mach numbers, rate
the
turbulent a
important
technologically.
the
flow on
beyond
of
the
which
in
an airfoil
as a
made
to
thicker,
however,
the
test
model
for
flow
bump.
in
a
on
described
8611 in
at
of
the
dimensional Case
experiment
I.
The
fluid mechanics
is
boundary
curvature
of
Bachalo
axisymmetry of
the generated sides
by
shock wave
the
test
8612
is
bump
in
Fig.
side-wall
boundary
rather
an
experiment
placed
described
both
on
layers,
by
This create angle
Cases
8611
Cases
the
the
bottom
At
"nd
the
ation
of
a
bump
bump can usually
These which
in
be
thicker boundary
may
or
may
not
be
experiment. (1979).
The
experiment
haa the advantages
zero
angle
information and
experiment
shock
waves
wall
Le
of
on
that
it
is
avoids
the wind-tunnel
attack
assures
two-
of
a
Duizet
(1979),
who
employ
wind
tunnel.
The
experiment
8612
in to
the
a
twois
two-dimensional.
The
in
their computational domain the
use of
LDV
systems
x and y directions.
determine
if
their
It
turbulence
choking.
wave
Compu-
for this case.
and is
shock
provide
mean-
urged that model
and
computors
can accommodate
thick shear layers.
deals that
the
largely
with ramps
interfere
shock
Compressi.-L
wave
placec
with tu
the
Corner (Settles et al., on the
the wall point
bottom walls
boundary where
the
experimental configuration and indicates 459
.-.-..--.....-................
very
the wing
formeL
advantage
the
layers.
on
of as
the tunnel and may cause some
feature
ched and Separated
stre.igthen
and
flow remains
and 8612
8611
Figure 3 shows the
S.-
of the
the boundary layers at
Delery
close to the top wall of
transverse curvature in Case 8631.
that
and
are
Although the shock wave generated by the bump interacts with the
2.
turbulence-moment use
bump
primary
Johnson
the model
and
flow over a bump
thought
effects,
and
with
zone
tora may have to include the top wall Both
can be
to sepa-
configurations
the
flow
At suffi-
flow.
dimensional
extends
an
Fig.
interactions walls
is
on
transonic
sufficient the
the surface
wake
desired depending on the objectives of a particular Case
in
shock wave.
such
The
streamline
a
Since
of
fields
occurs
more-easily-probed
accentuate
the
everywhere.
occurs
wall,
with
this shock wave can be
reatta'hment
motion
a wind-tunnel
terminates
underscanding
"Rcattachment"
downstream
on
flowing over wing,
that
over
layers,
of
Of course,
latter.
produce
or that
the strength
an aircraft
significantly
wake
the bump
boundary layer
resembles
differ
a -model,
over
Bump
.....-.....-
1976,
1979).
of a wind
layer. boundary
tunnel
Increases layer
the measurements
in
to
ramp
separates. that were
-
the
showed
flow
it
only,
to mean quantities
confined
are
quantLitLus aru
turbulence
that
Oil
indicated
the meaGurcmont;
Although
undcrstood
is
its side2s.
fences at
and had
twc-dimensional.
be mostly
flow
.-he side walls,
to
The ramp did not extend
made.
to be measured soon with hot wires.
The tunnel
suddenly
tails,
the
in
rapidly
of
separation.
may be
methods
is
ment
described
a
Just
layer.
shear
normal
et al.,
1980)
to
of
of
in
The expericavity,
the
that did
not
the
the cavity
near
the turbulence
oE
emphasizes
The experiment
layer
free-shear
the
reatta.ihment,
reattachment
This
the
free-
achieved
mean-
of
region
shear
maximum
the
layer with
direction.
free-stream
the
by a
preceded
generated.
length
the
edge
upstream
preliminary tests
although
equilibrium.
responding
adjusting
essentially
effects of
upstream
equilibrium,
velocity
remained
streamline-curvature
eliminates
is
layer
boundary
the
at
separation
that
streamline
dividing
occurs
layer ahead of the separation and created a free-shear
the boundary
disturb
a
achieved
experimenters
turbulent
By carefully
5.
Fig.
in
the
which
on
the plate
in
boundary-layer
is
-amp
the
that
except
8631
Flow
to
similar
is
field
flow
This
(Settles
Planar Free-Shear Layer (Supersonic)
Reattaching
Case 8641.
that
gradient
static-pressure
the
by
tested
severely
Also,
neglected.
usually
are
first-order
surface.
the deflected
cavity
but
1976),
Rubesin,
turbulence-
flow (Wilcox and Albel:,
incompressible
in
that have no counterpart
layer
the complexities
mass-weighted
the
of
terms
dc-
are shown
the boundary
two Mach number states without introducing emphasizes
geometric
experiment
that
in
equations
ý.Fiiid
a
the use of mass-weighted
to assess
suited
turbulence-transport
dilatation
Rapid
equations
transport
the
between
changed
is
1972;
in
variables
dependent
particularly
is
This experiment
4.
Fig.
in this
measured
quantities
the
and
flow conditions,
of
wall
pertinent
The
120.
of
the
on
occurs
experiment
by an angle
outwardly
deflected
this
in
investigated
field
flow
1986).
and Gavigllo,
(Dussauge
Expansion Interaction at Supersonic Speed
Case 8632.
show a cor-
do not
and the re-equilibra-
tion processes that occur dowT.jtream. FOR FUTURE DATA TAKERS
RECOMIENDATIONS the
Of
flow over
transonic
or
do not
systems
measurements experiment
such
measured fully
by pitot
thought-out
LDV
nonintrusive
suffer
It
tubes.
be made with other types of probes, et
(Ardonceau
found
1979)
al.,
only those dealing with In
sepa-
ambiguities
of hot
wires
important,
however,
instrument
from directional
pitot
the questionable accuracy of reversed
redundant One
the
a bump employ
these
regions,
rated
recommended here for computation,
five experiments
is
where
systems.
that
they are appropriate.
differences
between
velocities
tubes and LDV so large as to bring into question the data of a careOne
experiment.
then,
recomnendation,
is
that
futtre
data
takers
L
460
i".
..........
S...
-
.-
. , - .-
.
.
-
. .
-
,
.
.
-
_.
.,
-.
-. .
•.
*-
14 should occur.
use
redurdant
if
instrumentat' -n and
possible
the
resolve
differences
that
Other recommendations are as given in the Summitry on Shock-Wavu Boundary-Layer
Interaction Flows (Cases 8651, 8661, 8601., and 8691). EdAitors'
Note:
For
and
cither important comments on data iiweci
instroat'nt accu-
racY, sne also rho following in this volume: (i.)"Epr~et~ Data NCC1.3 for ttonal
Fluid Dynamics"
by Bradshaw et al.,
a position papet;
Coniputa-
(ii) veports of ad-hoc
committees on accuracy of hot-wire data and difficulties in compresqihle flow measuremferits;
(iii) comments
concerning
diffi~culty
in measuring
reversing
flows
by
J1. K,
Eaton and ot~hers in Flow 0420 and by R. Simpson for Flow 0430; (iv) the editor's com-
*
by S. J. Kline on the general nature of accuracy control and uncertainty analysis mor'.! in compres-3idhl 83610,
*
8630,
flows--a
footnote
to
genioral
comment
I
in the
discussion of
FLCwg
arid 8640.
~~Ardonceau,
'Tru F.. D. H-. Lee, T. Ailziary do Roquefort, and R. Goethals (19719). behavior in a sho'._k wave/boundary laver interact! on," AGARD Conference oil Boundary _L-avers '-Ex eriments, Theo y, arid Modelling, AGARD-CP-271 (September). lence
*Turbulert
"An investigation of transonic trrrbulený Bachalo, W. D., and n. G. Johnson (1979). bo~undary layer separatiOTn generated on an axisy-mnetric flow model," AIAA Paper 79-1479, William'sburg, VA (July).L *Delery,
J., and P. Le :ijluzet (1979). "D6couleruent r~sultant d'une interaction onde de choc/couche lirnite turbulente," T.P. No. 1979-146, ONERA. "Turbulent boundary layer/excpansion interacDussauge. J. P., and J. Gavig~lto (11980). sed," 'Ira-aux de 1'I.M.S.T. l.A, No. 130 au CNRS Contracts tion at supersonic 0NEKA, Institute de M.~chanique Statistique de la Turbulence, Univ.'rsLc6 de Aix-j Yarseille 11 (Jun(-). "A one-equation model of turbulence for use with the com-pre.,Rubes~lr,, M. W. (1c'76). st>Navter-Stokes equations,' NASA -1-C-73 (AprilD. "Incilpient separation of a Settles, G. S., S. 1Y. Bogdonoff, and I. F. Vas (1976). supersonic turh~ilent bnrindary layer at high Reynolds nunmbers," AIAA Jou., 14. 50196 (January). "Detailed study of -. J. Fitzpatrick, and S. .M. Bogdonoff (1c,79). Settles, G. S., ittaclied and separated compression corner flow fields in high Reynolds n-'.aber supersonic flow," AIAA Jou., '17, 579-585 (June).
"A study of Settles, G. S., B. k. Baca. D. R. Willi~ms, and S. M. Bngdonoff (1980). reattachment of a free chear layer in compressible turbulent flow,- Princeton Un~versity, AIAA-80-1408, AIAA 13th Fluid & Plasma Dynamics Conference, JiiuLy 14-16) 1980,
Snowmass.
CO.
"A turbulence model for high speed flows," Wilcox, 0. C., and 1. E. Alber (1972). Proceedings of the 1972 H-eat Transfer and Fluid Mechanics Institute, Stanford IVnivezsity Press, pp. 231-252. 461
NASA AMES 2'- 2' W.T. (21'o~POROUS WALL)
DIFFUSION 2.73SECTION cm
23.5 £ cm
_____
cm
/
6 *
cm9
,cm
Ti *
MODEL SUPPORT
I0~
t0.A)-
~0.87ý-
*
2
t1-
30
'P,(91
(13.12 0.1) 106/m
1 0.003; RO/L
k)5
IV T
_
_
r,.-rards(AtL~z-
-
-I
In.
Figure 1.
Test apparatus, Case 8611.
UPPER WALL
J-0.550
CIRCULAR ARC r z427 67-7
96
e/2 %12/
40
x
.
R
1
I29-49
156.88
-t-100--
286.37 LR-9t r-
Dimensions in mm
eanI
Stagna~tion Pressure anJ Tem~peratureLAg,.
ap,/Pe t J.5I
w,.nIce
4±IJ,j
Pressu.re
aL,'L..I
1.0Z L
Holographic1lnatIer,.Stear___-r)(
LAser Velociactte
esax il
F... be.., .a t. lt
1
j
l;%e
Test Configuration, Case 8612.
Figure 2.
462
6.
-'
-
-
Iii
Ilofln
profil.
Bror..ar2 r.±t..
-;r
-
-
-
-
-
-
-
.4.
LII
profil.
M-6,
t
ke/I
6.3
10~,/M
Tt 0 280 0 K
xR 0
t
-8,
16, 20, 24-
xx
-x
Measurements
Instrumentation
2%
Pitot tube, reverse Pitot tube
AP
Static pressure probe
AP/P
Total temnperature hot--wire probe
AT t/Tt
=1.5%
Shadowgraph, sch~leren
AU/U
±5%
Figure 3.
2
/P~ -±4%
Case 863]. (Settles et al.,
1979).
Prandt-Meyer 4
Expansion
1.76 6 Adiabatic Wall
0
m, 1
R
,
7
4900
0
Relaxation Test Zone Measurements
Instrumentation
~,U)
Pitot pressure tube
V. T i 1%
Static pressure probe (supplemented by method of characteristics)
TU ± 10% along u2, T', a streamline
Hot-wire stagnation temperature probe, 0.5 w~ dia, L/d -300
Cf van Driest transformed u, "law-of-the-wall" plot, K-0.41
Hot-w~ire 2.5 o dia, Lid -320 Figure 4.
Test configuration, Case 8632. 463
Su RBULENT.
COMPRESSION
FREE SHEAR LAYER
RECIRCULATION
REDEVELOPING S.L.
e~20 60
'40 0 50 30 20 SHEAR LAYER STATIONj
Inis trumentat ion Pitot Probe Static Pressure Probe Hot-Wire Total Temperature Probe Hot-Wire (Normal) 5 widia, L/d
-200
Measurements L~p/p
±4%, ± 10%@ R
tITt/Tt
-0.5%
Figure 5. 'rest configuration for Case 8641.
464
4
4i
"DISCUSSION Flows 8610, 8630,
8640
Fl~ow 8610--Transonic flow over a bumb. Case 8611--The Conference accepted this case a. recommended by the evaluators. Case 8612--The Conference accepted this case but recommended nel flow because the interaction feature of this flow.*
with
the
top wali
is
it
be treated as a Chan-
considered
an essential
Flow 8630--Compressible flow over deflected surfaces. Case
631/2--The Conference accepted these cases as recommended by the evaluators.
Flow 8640--Compressible flow over compression corner with reattaching planar shear layer. Case 8641--The
geometry of this flow case is
similar to Case 8631 but is
at a differ-
ent Mach number. It was accepted by the Conference, althcugh it was hoped that fluctuating measurements will be made and supplied to the data bank in the near future. General Comments 1.
H. V. Meier
(DFVLR):
How can you rely on an accuracy of
15% for skin-friction
measurements it there are no independent checks on that value? In my experience the accuracy of skin-friction measurements made with a Preston tibe is more like
100%. Response: The view of the experimenters was that their Cf vaiues, as measured, were within 15% of the local value. The Conference felt that further discu3sion of the problem of Cf measurement in compressible flows is needed to reach a con-sensus on the true state of affairs.t 2.
Another topic was that concerning the specification of zhe u,'stream conditions. It was concluded that the preferred prcz-edure was to let the computor pick his own starting conditions so that he matches reasonably well the data at the first station as provided from the data set.
[Ed.:
This comment has been incorporated into the specifications.]
tComment added in editing by S. J. Kline: Dr. Meler's skepticism is not unfounded, in my view. The discussacn during the meeting revealed the fact that the aeronautics community, unlike some .)thers, has not normally reported uncertainty values in meaAlso the uncertainties in this volume have been estimated by M. Rubesin and C. Horst-
L"
7
man after the !act for most of the compressible flows. Such estimates are better than no values for uncertainty, but are less satisfactory Lhan estimates made by the data takers, and far less satisfactory than initial control estimates followed by closing the loop to insure experimental control as recommended in the paper by R. J. Moffat in this volume. It is my opinion 'hat if the desired goals of accuracy in data as a basis for modeling and for checking computational outputs for compressible flows, as set forth by M. Rubesin and C. Horstman at several places in this volume are to be achieved, it will be absolutely necessary to incorporate systematic use of uncertainty analysis including feedbacks to check experimental control as suggested by Moffat and also to use redundant instruments. This is clearly a topic that deserves much further careful attention by the research community concerned with compressible flows. 465
S..
.. .. .. . . . r .. . ..
. . . . .. = I•. Z. - .
,
p
.4
SPECIFICATIONS
FOR COMPUTATION
ENTRY CASE/COMPRESSIBLE Flow 8610,
Case ;8611;
Data Evaluators:
Data Takers:
VLm 0410.
W. Bachalo and D. Johnson
Data flvel..torei, N.
TItb.l
and,f C.
W-lty
V1
•
•ar1tian.
Ot AtIt
_____.
Data Tae,.
Toot&is
or
C
C
t.7.r
V
"'rrasooic 7flo
• na
re
I
.,ohe.~
-
I
rreplee
.I
over & fiwip.
dl..
--1
, vohai:orIjI
d±/-.
11.
M. Rubesin and C. Horstman
C,
10i.°=
a.
K_
LV 4t
Other giot*&
"-I Xlc
P/Pi
S
0.2 <
PT <10
Wall-pressure distribution.
0ý5 < x/c < 1.5
2
U/U.
y
P
3
Yx/U
PT is tunnnl total pressure.
-0.5 < U/U,. < 1.5
4 curves at
0.0 < y < 0.025 m
1.0, and 1.375.
0 < K/UT< 0.08
4-Uv/U.
4 curves at
0.0 < y < 0.025 m
1.0,
0 < -Kv/U2
4 c,-ves at
< 0.04
0.0 < y < 0.025 m
1.0.
x/c
x/c
--0.25,
0.563,
-d0.25,
0.63,
and 1.375. x/c - -0.25,
0.563,
and 1.375.
Special Instructions: This recultir?
test in
case
considers
a shock-wave
the
transonic
boundary-layer
flow
interaction
region.
oo
.
.;,,-..
466
.
.
over
an
axisymmetric
with an extensive
bump
model
separated-flow
PLOT 1 CASE 8611 FILE 2 0
-0
¢~0000¢0¢000
__.
--. =""O :...
0.4
P/2
-
CA o°
';
86
0
0
00
1FL
S
,,11
0.3 11.5
0-5
-
'0
F .LnL
S.
.
O5
1.5
X/67
.r
:_...:. =
•..-.
.
,-- 030 .
-467
.
.
0'. .
- .
..-
. .
Fl
PLOT 3 CASE 8611 FILES 3,4,11,14 X/c
0
1
-0.25
0.563
1.375
-
1.0
0
+0 0
+ 00 10
y
00
{m)
,
0
0
j o
°4
t
0
0
200
01
0
10
t
2
0~
o
K/U:.-.
50
0
50
0
50
0
50
PLOT 4 CASE 8611 FILES 3,4,11,14 xc-
0
I
I I
I
1,375"
1.0
C.
0.563
-0.257
0
0
T
I
(cm)
=
•
i
I
-
T7L
j o0
1
I
I ±j•0
1?.
o
0
o
I
4-
¢_I"0)...
-0 0
o
I
I
0
S2c
20
200
C
-UV/U.
"1
468
.
-
-.... I.
.-.-
-
-..
- _
-
.
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPRESSIBLE Flow 8610, Case #8612;
J. Delery and P. Le Diuzet
Data Takers:
VICTWSAJ.
FlOV $610.
M. Rubesin and C. Horatman
Data Evaluators:
SNWIAA *Trlo.jo.1
LbO81o %S C. Oor~t"a.. K.
Data Evaio-ioe8i
Fl-o *-Ofr
W~hrofStegi,.. 14.ee"(6d
Cal..
iii.
i GP~~r
Vs
U
Cae
V o thero
.1
C
L. 11
~
_______________I
Ordinate
Plot
2as 24. 20
8
Pa$
28
- 710.ooI I (bsd 1.37
is
X
PPrefý-"
is
Wall-pressure distribution.
1.0
0.2 p/pref P/Prf <
Top wit is 1".ortao. probie..
Comments
Range/Position
Abscissa
mhtia
itther
0.2
0.2 < x < 0.4 m y
2
U/U..
4 curves at
-0.2 < U/U. < 1.0
0.310, 0.350 m.
0.0 < y < 0.03 m 3
y
O
K/U~
4 curves at
< 0.1
vU.
-0.02
x as0.280, 0.310,
0.350, 0.40 m.
0 < y < 0.03 m 4
x as0.270, 0.280,
< uývIU2, < 0.0
4 curves at
x
-0.280,
0.310,
0.350, 0.40 m.
0 < y < 0.03 m
Special Instructions: This
test case considers the
in a wind-tunnel side wall.
transonic flow over a two-dimensional bump mounted
The resulting flow field is a shock-wave boundary-layer
interaction with an extensive separated-flow region. energy
from the data set, assume
K -
0.75 u
2
+ vF
To compute the turbulent kinetic For normalizing the data, use
V_- 382-m/s.
It
is recommended that this flow be computed as a channel flow because the inter-
action with the top wall is considered essential.
469
PLOT 1 CASE 8612 FILE 6
0.75f 0 '
0
0 000,000 C10'00Q
II0.50 -•["ii
[
¢'
0
i00
~'ref 0.25
•--_--•:•
-
"0.00 1
0.2
0.3
0.4 x (to)
""-..
~~~0.03
"PLOT 2 CASE 8612 FILES 16,13,24,30
• x
r.02
0.
27
•
0.310
0.280
0oo
-C)
0.350
-
0 IL -4
""0.01
0
@;'4
•'t N.o-
o
4
0
-1-
0 0 •i 0
4O"aCO ;o) 0.00
ro 0-C-
0
O0
'
4 lIo
,,,,
i
I
i
0
10O U/Uw.
470
C,
w,
I
C C
*I
,
C)
±0
0
' ..
PLOT 3 CASE 8612 FILES 18,24,303 z-0.280
a
0
0.310
--
0.02 >y
10
0
~
1
00 i0
00 00
0
0
0
t0
t
0 0
0
0
0 000
00
0
L
1-
...
1.
L
0.2
0.2 0
0.2 0 K/UTJ
0.20
0
4
1:
0
00
0.00
0
.0*350
PLOT 4 CASE 8612 FILES 18,24,30,35 0.030
0.
0*5 .40
0.310
x0.290m
OZ0
~
0.020
0
.1
0.005
F
oo0c 0.000
2 00
*00
o
0
0
00
C,
-.
2
0
I
FOR COMPUTATION
SPECIFICATIONS
CENTRAL ENTRY CASE/COMPRESSIBLE Flow 8630,
Case #8631;
Data Takers:
G.
Data Evaluators: Settles,
S.
r 1crI~iAL. Vlow 9610.
Data 9SvluAtri
N. Lubqaio a4d C.
los
U r •lstl
|ly
y
U/ux
0
U/U.
y
Xep
5
Re6.
Xreat
io-0 .,2
,-.-
-0.1 4
0.l .tctod Sr1.c.s."
2 curves for
i
< y < 0.03 m
4 curves for
e
< U/U<
x - -0.0381, 0, 0.0381,
m.
< 1.0
0 < y < 0.03 m
4 curves for
-0.1 < U/Uot < 1.0
x - -0.0381,
-0.02 < xsep < 0.01 m -0.02
< xreat
0.5x1O
• 2'
6 <
l6* and 20'.
-16"
e
<8x1O
0.0762
at
0, 0.0381,
reattachment
X
2.
at
- 200
x separation vs Re
0.01 m
e6
24-.
16.0an
f 2 curve -t
-0.05< x (0.5
x
ofl-
a Profiles
01
2
3
I..
iComenrtd
ors
pf-.5<
"31
Horstman
Fitzpatrick
tummy
or stgtton
rdnbtr
V.I.
and T.
Mor.tamae. 'CompresiLbli e
Slt C o. $
M. Rubesin and C.
Bogdonoff,
0.0762 m.
and
6
vs Re
_--
6
(output only). 1 curve for
0 -
200.
Special Instructions: This speeds. lated, surface 0,
test
case
There corner
are
four
angles
measured
y is
considers
of
from
two-dimensional
a
sets
of
data
oil the
160
and
200.
For
and y
is
the corner
compression
tape. these
the
Only flows
two
x
distance
corner cases
is
the
normal
are
at
supersonic
to be
distance
to
calcu-
along
the
(at
x -
the wall
normal to the upstream wall).
472
_--:-'- :-'- -.'- .-•-:-. '2 '.: -- :-. '- -".-'2- Y I-.: -:
S.f •t~
:•±•,,-,•:ji•.':
-
•
• . --
.•
,L .• "
. " :' -• ::-.:- : .:. •
:.
_-
•'
i . ."- .--. -
. %",
,J
.
'
=:
- ...-. '2 -' --. '
.... .','
.. "
"
;
"-- - "-.: " ,-,
" .:.-
"
.: -.
;
° "
" .
PLOT I CASE8631 FILES 3.4 "16
6 -20'
0
3 0
1
o;
8
000-
0.
0
4Z
PLOT 2 CASE 8631 FILES I12Z o
0.001
K.
0
0
..
0 0
"00 0.000 .
X (i- )
473
.
•jj. PLOT 3 CASE 8631 FILES. 2-4.27,,0.3i 0 L L I _4 L -0.0381 0.0 0.0381 4 0.0762 a
- 1,1
163
" o 0
1
0.03-4
o4
' .4 v
4
~0
y
0.)2
I
•
I
,
C./
g
,i
100
0o
U/U
PLOT 4 CASE 8631 FILES 33,35,38,40 0.04
003
0381u
-
0.0
"
0.0381
•
200
0.0762
-
-
"0
0
0
0.02
:o
B MW "1
0-
ji
ooo
0::.00
jj
gi
1-
- 0.0 -
1
-i-
-
--,-
,-U/U
-,'.',',474
.
-.
.
.
"
.
.
.
.
.
. .
.
..
-C<.
PLOT 5 CASE 8631 FILE 14
e-
200
0
.0
DS 0
"
...')
-V'
J
0
C 00
•..
_-
C ij
0
-
x
sep reat
(deg.)
(dog.)
Re,6
-:<.
" /475
SECIFICATIONS FOR COMPUTATION
4
ENTRY CASE/COMPRESSIBLE M. tRubeatn and C. Horstluan
Data EValuator3:
Flow 8630, Case 08632;
Data Take..:
J. Ljuseauge and J. Gav'.glic Fh2TORVAL.i1104H.MI
71". 8630.
Data 9111eh.tral M. L..b..l. .o.I C. Mo e-aw..
e-i.
C...
Ii
T.. tr
1,t
Plot
Ordinate
1
Pw/Pt,ref
a.sm
2&L4
Abscissa
.
ui/Ure
x measured along upstream wall.
0. 15 mn -
9 measlired from corner along the deflccted stream.
0 < U <500 rn/s
Mean velocity profiles at
0 < y < 0.02 mn
x -- 0.0325, 0.0061, 0.0313, and 0.098 mn.
x
0.0 < u/U
.
Wall-pressure dijtributton.
~w Ft,ref (0.20 P
y
rNot.n.k
Comments
-0.0725 < x <(0 m
-
*3
hOO. M
ai
1:1
Range /Fos1.tioii
0.0
U
lb-. Vi-o o... D~f!.,t.d 5r~..
V
O < a
2
...
r1 CP
8.
*C
2
Strermwise component of turbu-
< 0.004
lent kinetic energy along the
-0.005 <. x < 0.006 mn
streamltne
"pLd 6 a
_____________________________t,refat,ref
L
Special Instructions: Instr~iments pressure probe
4PitoL
Static pressure probe (8uippleinented by Wethod of characteristics) Hot-wive stagnation temparature probe, 5-p dia, Z/d Hot wire 2.5-ýi dial kid *
-300
-320
Neas-irementL p, U, V, T ±1 u2
'i
,
RT
alone. a atrcamline
± 10%
Cf van Driest transformed u, 'law-of-the-wall" Plot, K
0.41.
476
.7
...
.
.
.
.
.
.
0.063
.
.
.
PLOT 1 CASE 8632 FILES 31,32
'"-
"0.2
0
'
"
4
~PiPt re f
-•
0.1
J] ""
-4
• 00
,,
o° oo
00
,,
0
0
0.00 •
.T
"-0,A
-0.0.5
0
0
Sx •
: S4
F'
• 0.02
1
'-----------.
x --0.C325
s-i-
-4-
0.0061
0
5
o .
;0
.F-c
0
*0
0
0
0.1"
PLOT:'; 2, CA$S.E 8632 FILES Fm'i3.16.2 2 !'i -i
Si
Si
0.05
(M))
500
o
-7-o
-l -
_
0 77
io
•
i
'¢
"
500
0.-C313
-Fri
0
c.
_
53&
...-
500-i
0 V•(
___--___•
•477
---
..
I
[,' o--
0
.
a
0
0.004
00
0.0102
-0.005
0
0)05
[7
.
.
]
..
UgiCIFICAAIONS FOR COM.PUTATION ENTRY VJSE/COt4PRESSIBLE Flow 8640, Case 18641;
Data Evaluators:
M. Rubesin and C. Horetman
Data Takers:. G. Settles, B. Baca, D. Williams, and S. Bogdonoff Flame,640.
Deta £d.2laatardI I.
b9eetm OudC. Wroral..
'C..roesiblek
"w~er Tot1~s
Daa
Cw
?.ml
Other.
oe
rIo[ko I
Or
I N
~
o
2
-,2
or
>' 0
S6e.
Plot
over Coapresoslo 0r0.rsr with I..ltachito4 Plamar thsr Layer.'
Moor.
a.,/4cnsu
Come
flow
of Statical too.,redI
-
-
-
-
lay Ar darakop-Irt, T.OILttecwat, ARA dowitatr~o. tovoiopoa.t. VI0*01'4A
1Pt:-o
-
El.
.
,I
l,2S "O
Ordinate
Abscissa
Range/Position
Comments
p/P. P
,c
0 <. p /p. <.4
Wall-presVgure distribution on
O < x' < 0.2 m
the ramp.
0
Skin-friction distribution on
2
f
3
x
U/U..
y
Cf~< 0004
Cf
____
/2 p
0 < x' < 0.2 m
the ramp.
0 < U/U_ < 1.0
Mean velocity in the free-shear
0 < y < 0.03 m
layer at
x - -0.0254, 0.0381,
0.0635, and 0.0889 m (4 curves). 4U/U.
y
0 < 11/U" < 1.0
Mean velocity on the ramp at
0 < y < 0.02 m
x'
0.0686, 0.0965, and 0.1549 m
-
(3 curves). Special Instructions: This
test case considers a reattaching planar free-shear layer (generated by
backward-facing step) reattachinig upon a 200 ramp at supersonic speed. and skin-friction data comparisons are needed on the ra', parisons are needed in the free-shear layer, ramp. *at
a
Wall-pressure
Mean-velocity profile com-
the upstream boundary layer, and on the
In the free-shear layer and upstream boundary layer, comparisons are to be made
x - -2.54, x'- 6.86,
3.81,
6.35, and 8.89
9.65, and 15.49 cm.
cm.
On the ramp,
comparisons are to be made at
(x is the horizontal distance from the step,
X, is
the distance along the ramp measured from the corner and y is the distance normal to the model surface.) 479
PLOT I CASE 8641 FILE 2 4 0 000
o000
00 0
3
00 0 0
0
00
010
0.000
010
0.004
0.0031 I
0.~002
80
~~~.001.......
.......
.
.
.
.
.
.
.0.
. .0
.
.
.
.
.
S5.
. 0 .2 1
.
.
80. .
.
.
.
.
.
.
.
..
..
.
.
.
.
PLOT 3 CASE 8641 FILES 3,5,6,7 x - -0.0254
*
o.0381 o
0.0635
0.0889
I9I
U/i3T
oio
1.0
u
.oooIa0
0.5
0
S0
1I0
10.5 CI oiuc 0.0 S000 002
1.°0
.0
00
-'0
002
.
0.002
v.
0.02
"'
I
0.03 0.02
0.03 002
0.03
.
~PLOT 4 CASE 8641 FILES 8,10,13._
-"
I
,,r
x
-
I
.
0.0686 i
1I'-
I
0.0965
~~1.0
,',
-
0.1549
--
"'
*
H
-. S-,
800
0.300
,
0.0
-{0
0.01
0.02
0
0.01
3.02
I
0
0.01
0.02
-
y (in)
1:.
r.,
481
-1
-
.
.
.•` .
.v . `` .
.
....
`
;-"i " - - '.-," :':• "-"'---)•"
. • . .
.`. --
l"
-'=•
.- -..-...-. :"
-'="
.-- .-'".-'.""-.'=I
- •
-'
-"-' - '•
= "
i)
, -".".--.--..-...%"•
".>
•"
v - --- ,"
'"•
"
-•...
---
''
....
q
NEAR-WAKE FLOW (SUPERSONIC)
AXISYMIETRIC
Flow 8680 Evaluator: by D.
(Prepared
.\
A.
Favre
J.
Cockrell
)
SUMMARY INTRODUCTION Experimental
data
(1978)
flow developing in
for steady
numbers
Reynolds
of of
terms
ensure
were
were
of
near
turbulent
the
mixing
downst
and
or
Large
et
Dussauge
and 3.36
-
and 2 x 10
3
and velocity
The
based on
104,
3
1 x 10
pressure
2.3.
number was
al.
body of
i of a 40-mm-dia.
1.68 x 10
were
flow separation,
,
respec-
gradients
strongly out of equilibrium.
which is
'he nominal
nozzle.
is
boundary
surface of
performed,
is
bE.se wedge, quojected
layer
i03t
total
pressures
in
terms
of
second
layers
for
a the
in
the
0.375
boundary-layer
and
2.3. 0.75
terms
of
x 10 the first
momentum
series
first
of
atmo-
thicknesses
both cases,
In
Two
3
just
for the number
thickness.
tests,
ridges
To were
the model downstream of the nozzle. Fig.
through
fan,
an expansion
forms
by turni-ig and then trarnsforms
recirculation properties
The boundary layer separates from the
1.
accelerated
to a compression
encloses thus only
the
of
was
number
4 and I were 1.68 x 10
for the second.
shown in
is
Mach
at
determined
set at zero
nose section was
eamlined
with a
performed,
thickness,
physical
flow configuration
layer which The
supersonic
3.36 x 104 and 2 x
fully
The
a
numbers,
placed on the lateral
model
described
(1977)
free-stream Mach
flow separation near the base wedge,
of
series; in
in
experiments Reynolds
upstream
is
two tests
of revolution
body
incidence
spheres.
first
the near wake,
al.
CONDITIONS
A 40-mm-dia.
series
the
et
Gaviglio
the fully turbulent boundary layer,
EXPERIMENTAL
angle
in
on upstream momentum thickness.
based
in
exist
of
thickness upstream of
boundary-layer tively,
reported
a supersonic stream for which the
in
revolution
are
zone
of
in
which
the expansion
no
turbulence
region
a
mixing
into a wake. measurements
and the compression
from the mixing layer by The recirculating zone is separated region were conEidered. a randomly fluctuating interface or dividing surface, which in a radial plane becomes a dividing strcamline.
Institut
de Ný4canique Statistique de la Turbulence,
tUniversity cf Leicester Engineering Department,
"['K'
*Note that here
Sin
thi
Gaviglio et al.
momentum
thicknesses
have
Marz:°Ilc, France.
England. been reversed
in
order
(1977). 482
V, %
-.
.
-
from that given
EXPERIMENTAL METhODS Mean-velocity
Two approximations were
ments made by probes that were moderately sensitive to yaw. made
the mean-streamline
to
and
Velocity
temperature
from pressure measure-
and mean streamlines were deduced
profiles
in
derivations
were
fluctuations
to account
order
determined
for
using
the errors which arise as a consequence of anemometer
there was good agreement
that
obliqueness.
0.9-mm-long
platinum-
Gaviglio et al.
plated tungsten hot-wire sensors having a diameter of 3.8 wm. discuss
their
imperfections
(1977)
but show
turbulence intensity measured up-
between longitudinal
results at a similar Mach number obtained
stream of flow separation and corresponding by Kistler. LATER EXPERIMENTAL WORK Later
experimental
sizing the expansion
interactions wave
or
the
work which shock
at I.M.S.T.
performed take
p!sce
wave.
In
the
between two
has been directed
towards
empha-
boundary layer
and either
teat
two-dimensional
parallel
sections
the
models of the flow configuration have been devised in which a wall replaces the dividIn the first teat
ing streamline between the mixing layer and the recirculating zone. the wall is
section,
compressively
deflected ;ccuracy
in
are known. (1981?)
deflected expansively
details
The
6 degrees.
through
turbulence measurement Further
through
of this
and Debieve and Gaviglio
later work
(1981?);
12 degrees,
resulting
improved,
has been
in
flows
the second, are
much
it
is
steadier,
and experimental uncertainties
are given
computational
Duassauge and Caviglio
in
resulto through toe 5-degree
shock are compared w.th experimental data in Debieve (1981?); for further details concerning these three references, apply to the Institut de MScanique Statistique di la 12, Avenue Ggn6ral Leclerc,
Turbulence,
France.
13003 Marseille,
REFERENCES "Bilan de tensiot:s de Reynolds lans une interaction nade de Debieve, J. F. (19817). choc-turbulence," to be published oy C. R. Acad. Sci., Parts. "Shock wave turbulent Debieve, J. F., and J. Gaviglio (1981?). action on a compression corner," to be published
boundary la.--r inte--
"Dersi~y changes and turbulence Dussauge, J. P., J. Gaviglio, and A. Favre (1178). production in the expansion or the compression of a turbulent flow, at supe-isorlic speed," in Structure and Mechanics of Turbulence I11 p. 385, Sprlnger-Verlag. -Interaction Dugsauge, J. P., and J. Gaviglio (1981?). expansion at supersonic speed," to be ptibhiehed.
turbulent
layer
boundary
"Behavior of a Gaviglio, J., J.-P. Dussauge, J. F. Debieve, and A. Favre (1977). Phys. Fluids, turbulent flow, strongly cut of equilibrium, at supersonic speeds, 2-' S179.
.
483
:" ..-
'.
" ..-..
.
.
-.
.
.
..-.
.
....
.... •.
,...-.
..
.
..
.
.
.
-.. .
.......-.
•
_.
•*.•_-• ._..._
- .
.- .-.
,
_
r
Figure 1.
Sketch of the flow (8680).
DISCUSSION Flow 8680 The Conference re'-.owmended that this flow be held In abeyance until the following eat& are received:* 1.
Detailed i-aformation on the flow field upstream of the baae of the model.
2.
Base-pressure measurements.
3.
Un--rrtainty analysis of data.
4.
Details of how the pressure is measured along the wake centerline.
5.
Optical pictures of the flow field.
6.
Circumferential data at base of the model when these data are available. The evalutors will examine this case for possible inclusion in the data bank.
A. Favre agreed to forward these data.
[Ed.:
This flow was not used in the 1981 meeting.] 484
SESSION X
Chairman:
J. McCroskey
Technical Recorders; R. Strawn R. So
Flow 865
Flow 8650 Flow 86600 Flow 86900
485
SHO(Y. WAVF
ROUNDARY-LAYER
-
INTERACTION FLOWS
Flows 8650, 8660, 8600, 8690 Cases 8651, Evaluators:
8661,
8663,
8601,
M. W. Rubesin* and C.
8691 C. Hlorstman*
SUMMARY
SELECTION CRI'LEKTA The existing interactions Reynolds
experimerntn
cover
a rather wide ranga
numbers.
To pick the
experimentb were grouped experiment * *
was
chosen
quality data. boundary either
surements field.
influence had to
basis
test
the
of
the
cases
Finally,
boundary-layer
Mach numbers and
foi" this conference
largeot range
surface
be
precisely
pressure
and mean
measuri-ments
two-dimensionality
all
known
were
had
fluctuating
variation
of
measurements a
flow.
desired.
be quite
such
As a
as
If
well
minimum
had to
the meathe
Mach
documented.
Reynolds
is
Compati-
flow field were
or
flow
the experiment
Although not necessarily the
of
turbulent
throughout
flow profiles
throughout
parameter
and variety
The upstream
defined.
also
to
of variables
dnd downutLeam boundacies
ll.ke experiments was also checked.
mean flov and
turbulent
configurations,
equilibrium and the upper
skin-friction
with other
sired.
experimental
flow field or
the
include
:wo-dime,.sional,
dant,
flow-field
Each flow chosen had to be a well-defined
Surface
bility
of
of shock wave,
into several categories and within each category a perticular
on the
layer had to be in
not
on the behavior
redun-
also
de-
or
the
number
shock-wave strength was an important consideration. -4
Case 8651 in
- Axsymmetrc
this category
*Incident shock Kussoy
wave
and Horstman
The measurements plete
wean
separated
a concentric on
the outer
(1975)
included
flow-field
flcw,3.
Shock Impingement
(Supersonic)
shock-wave surface
was chosen.
of
The
Hot-wire
for
two
generator a -ircular
experimental
surface pressure,
data
" is
shock-wave
to produce
cylinder.
The
a conical
experiment
geometry 's shown
skin-friction
in
and heat-transfer,
strengths
data were also obtained,
used
resulting
in
Fig.
1.
and com-
attached
but the accuracy
by
and
of these data
were not sufficient to be used for compariwzki with computations. Cases 8661, In
8 66 2
this
1 and 8663.
category
experiments were chosen
three
Three-Dimensional flow
fields
for computation.
not finally ,i.ed
the
above
ThQ first .ase
NASA-Ames Research Center, Moffett Field, tThis case was Data Library.
Shock Impingement (Supersonic)
meL
CA
criteria.
Two
(Case 8661)
is
of
the
three
for an oblique
94035.
for the 1980-81
Co:.ference.
It
is,
however,
in
the
486
- -
:::::: ::: ::::::::: ::: ::: :: :: ::: :::: :::: ::::-::: :: ::::: ::::::::: -- :
* - *.
-
I : : .-:-
**.~:~**** -' -
'-'*
. -- . : : - '.
*
j
:: . . :
*
-.
.,
:4
."*
.
.4
i
: ..
-
shock wave boundary-layer
*
M - 3,
interaction
(1976).
at
8663)
chosen Js for a conical shock wave boundary-layer The flow geometries
this case plete Fig.
included:
mean 3.
data
planes.
to mean
addition
and
1975;
1976.]
The
(Case
second case (Case
interaction by Kussoy et ai.
ahown in Fig.
for Case 8661 is
surface-pressure
flot-field In
by Oskam et al.,
[A similar experiment
8662)
(1980).
has been done
by Peake
2.
The measurements for
skin-friction magnitude and direction;
The
surface
flow geometry
and
flow-field
for
Case
data,
the
8663
is
com-
shown
measurements
in
also
include fluctuating data on the windward and leeward data planes. Cases 8601,
8602
Impinged Normal Shock Wave,
.
"Transonic In
-'.
this
category
Matter et al.
(1976);
Kooi
The
for
(1978). this
c.a-qe
two
Speeds
flow
fields
were
flow geometry mean
surface-pressure
the axisymmetric
and
shown in Fig.
4.
skin-friction,
The measurements and
to investigate
the effects
number at constant Reynolds number and variations The flow geometry for Case 8602 is
the two-dimencional experiment obtained at three
of
both
mean and
In addition several experimental data sets of mean
surface and skin friction were obtained
at constant Mach number.
experi.ment
and the two-dimensioaal experiment of
for Case 8601 is
fluctuatirg flow-field parameters.
*
chosen,
Mateer and Viegas (1979),
incrluded
"free-stream Mach
Boundary-Layer Interaction at
of Kooi
(1978).
of variations
in
in Reynolds number
shown in Fig.
5.
This is
Mean-surface and flow-field data were
free-stream Kach numbers resulting
in flow fields with various de-
grees of separation. Case 8691.
Nonlifting, Transonic Airfoil with Shock Separation
Tha experiment by McDevitt et al. ment of were
a
extensive
fluctuating *
transonic
in Fig.
and
airf,.-il
( 1 9 7 6 )t was chosen as the most complete experi-
with a large
include:
shock-separated
surface-pressure,
flow-field data in the separated
region.
skin-friction,
flow region.
and
Tle measurements complete
mean and
The flow geometry is shown
6.
RECOMMENDATIONS FOR FUTURE DATA TAKERS
SWhen an experiment is designed, defined. this -
is
All
boundary
especially
equilibrium boundary
conditions
zritical
for
layer is
care mu3t be taken that the flow field
must be tranlionic
specified, flows.
also important.
is well
or shown not
to be
important;
The establishment
of
an upstream
Experiments should also be designed to
tezt a particular aspect of turbulence modeling when possible.
This case was Data Library. 'See
not
finally used
also Seegmiller et al.
fou the
1980-81
(1978). 487
Conference.
Ic is,
however
in the
-L
Improvements
0
and
hot-wire
ments
in
the
anemometers
. r gathering
boundary layers
layers
occur
tuatiag quantities wall
where
The
guiding
the
expressed
components
mean
theoretical
a
from laser-Doppler
possible to consider these instru-
models
mechanics
with greater walls.
associated suggests
spatial
Redundant Pitot
with
that
improve-
supersoni:
measurement.
resolution when
should
these boundary
be used
Continuing effarts
wind w.thin
measurements of both mean and tubes
are suspect.
applied of
tc measure
the
Reynolds
two-equation modeling strain
utilized
length
scale,
foundation.
measurements,
data
fluc-
to obtain near-
should
be
made
to
the quantities tensor
to models
and turbulent and
oll
stress
stress.
they
that account Efforts
Favre mass-weighting
can.
will be most
for the
should
in
Mea-
useful in lack of
be expcnded
a quantitative
to
manner
comparison of LDV and hot-wire measurements.
equations
as
small
fluid
the Morkovin hypothesis
through the careful
it
the
parameters upon which turbulence-model
also recommended.
through
equilibrium between
Of
of
should be
the
modeling
assess both
studies
makes
of
surface skin-friction measurements.
instruments of all
years,
relatively
LDV measurements
obtain more accurate
-"surements
The
are
interpretation
of turbulence
on the wind-tunnel
.
and
recent
can be performed
-
data
in
data
"ments can be made. "tunnels utilized for
operation
in
second-order
frequency
Two-point
or other measurements
modeling,
scale,
or
the
scale
dissipation
correlation-length
equation,
rate,
has
measurements,
the
or
be
it
weaker
multipoint
directed toward defining better scale equations
in
compressible flow should be attempted. Some thought of modeling, the
should be given to experiments
when some of
models account
will have will
modify
raw data lators seeding will
for
to consider
the
time,
will
no
of
techniques
be
as it
appropriate.
"continuous"
;-uch of
tics of hot wires
data
their meaning.
of
largest
the
relationship
with subsequent computer
longer
so that
contribution
the phase
data-recording
in
lose
the dynamics of the
designed to guide the next generation scales
remaining
for,
analysis.
Studies the largest
The continuous,
scales.
at least,
will require
211
are calculated,
the
These measurements largest scales.
continuous
The use of have
eddies
to
recording
rms meters
be made
can be
to
achieved.
high-frequency-response
should lead to multi-sensor experiments.
and when
Again,
This of
the
or corre-
increase
LDV
Ristograms characteris-
multipoint measure-
ments will be critical. Finally, tigated in is
limited.
three-dimensional
more detail.
flow fields
with and without
separation must be inves-
At present our understanding of three-dimensional
The available experimental
data base is
488
almost nonexistent.
flow fields
tj REFERENCES
t4
Koo.,
3.
(1978).
W.
"Influence
boundary layer interaction,"
Kussoy,
M. I.,
of fLeeestream NLR-MP-78013-U.
and C. C. Horatman (1975).
Mach numbet
on
transonic
shock wave-
"An experimental documentation of a hyper-
Eonic shock-wave turbulent boundary-layer separation," NASA TM X62,412.
interaction
flow
-
with
and
without
K,.asoy, M. I., '!. C. Horstman, and J. R. Viegas (1980). "An experimental and numerical investigation of a 3-D shock separated turbulenit boundary layer," Paper 800002, AIAA 18th Aerospace Science Meeting, Jan. 14-16, 1980, Pasadena, CA. M'-teer, G. G., A. boundary-layer D.C..
Brosh, and interaction
J. R. at t
Mateer, J. G., and J. R. Vl'2gas normal shock-wave/turbulent Williamsburg, VA. :TcUevttt, J. B., L. L. Levy, thick circular-arc airfoil,"
Viegas .nsonic
(1976). speeds,
"A normal-shock-wave turbulent AIAA Paper 76-161, Washington,
(1979). "Effect ot Macn and bounddry-layer interaction,"
Jr., and G. S. Deiwert (1970). AIAA Jou., 14(5), 606-613.
Reynolds numbers on a AIAA Paper 79-1502,
"Transonic
flow about a
Oskam, B., S. M. Bogdonoff, and I. E. Vas (.75). "Study of three-dim"ensional flow fields gene_-ated by the interaction of a skewed shock wave with a turbulent boundary layer," AFFDL-TR-75-21.
Oakam,
B.,
I.
E.
boundary layer AFFDL-TR-76-48.
Vas,
and
S.
iatetactions
M. Bogdonoff in
thcee
(1976).
dimensions
"Oblique a,
Mach
shock wave/turbulent 3,"
parts
I
and
II,
Peake, D. J. (1976). "Three-dimensional swept shock/turbulent boundary-layer separations with control by air injection," Aeronautics Report LR-592, Notional Reseqrch Council, Canada. Rubesin, M., A. F. Okuno, L. L. Levy, Jr., J. B. McDevitt, and H. L. Seegmiller '1976). "An experimental computational investigatlon of the flow field Pbout a traitaonic airfoil in super-critical flow with turbulent boundary layer separation," Tenth Congress of the International Council of the AeronauticAl Sciences, Ottawa, Canada, October 3-8. H. L., J. G. Marvin, and L. L. Levy, Seegmiller, transonic flow," AIAA Jou., 16(12), 1260-1270.
J-.
(1978).
"Steady and
.
unsteady
4
.. i' .'2" .-i " ""i'. " -.. i-.i-i . ." -.
i: '-489
Table
.
Uncertainty Estirmates for Cases 8651, 8661, 8663, 8601, 8691 Case No. 8651
Quantity
Uncertainty 10%"
Pw W_ w
± 15%
iqw
j± 10%
U(y)
t 3Z
U(y)
reversed flow region G5
-
± 12%
p(y) 8661
•
8663
Pw±
1%
c±
10%
U(y)
± 2%
C,(y)
±0.20
Pw
8691
5%
TwW
t 15%
U(y)
±3%
ai(y)
± 0.5
-~2 12 (wJ -2,/ 1-2 ý12 •vJ, (uj,
±1•5%
u
8601
35%
W.• ,•-
'
± 15%
(uv
Pw±
5%
w
±15%
U(y)
± 3%
p uv
± 15%
C
± 0.02%
p Cf
±15%.
U(y)
± 4%
uu2 + v2
±8%
uv
± 8%
490
................................
.
.
.
SI
-
3
6.
2.5cm6.8,
.-
Z,5cm
"---
Re6
0.4 x 106
-
330cm CM \20,ýý
S,
d'3m
81 rcm P..
*Iio
64.4TP
T)PICAL
cm
'I'SrRLW EN TA':, ý.1
TANGENT
?
"T,
POINT VARIABLE
14()-165 cm !00
50
0
150
X,cm Figure I.
Test configuration,
Case 8651.
S-' •:CIO
DATA =
"
---------
I
•,PLANE
.4
=..1
M.
UPSTREAM BOUNDARY LAYER
Figure 2.
C&se 8661,
2.
6.
0.51
6 0.2 x 10
Fe6-
three-dimensional shock impingement. ,491
.
..
cm,
424
INSTRUENTAT
ENPOTEBD
ý
SUPPRTE
41
1501
Figure 3b.Ov
detaeileof seral
test configuration, Case 8663.1
4924
M=.. 1.3-1.5,
6.
2.5 cm,
R
- 8.5-225 x 106,
R
- 3.3-6.0 x 106
SHOCK GENERATOR DIAM
Figure 4.
Experimental test configuration, Case 8601.
P.4
L
ý49 7 1/
/ -
Fiue ts/ 7 7" 7• 7 7-/ 7 7 .Exeiena
-/ C111e 8602. 7 .1 / / oniurto
M.. 1.4-1.46, 6. Re6= - 0.3 x 106
Figure 5.
Experimental test configuration,
Case 8602. .
N•
493.'"
..
-; ' 7 2//•-
..
1 cm,. %
Ný BEL LMOUTH
ý
IO
ýCIý
ýS
-
AcI
TRANSLATING WEDGE
I
-2
1I
0
2
1
3
4
6
5
X/c
M.- Q.785,
Figure 6.
Rec
1-
1ok gnparatian. Case 869i, inonlifting traK1Aonic airfnil with a.,
'494
10 6 .
L
DISCUSSION
Flows 8650 and 8660 Cases 8651 and 8661: I wish to comment on the necessity of specifying stagnation and static
M. Morkovin:
temperatures
that arise
There are hidden uncertainties
the boundary layers.
in
from unknown thermal fields in flows of this kind. The total tfamperature
C. Horstman:
This infor-
field was measured at each profile.
included in the data file.
mation is
The data libary will record all the data supplied by the experimenters,
S. Kline:
not
only the information required for specifications. shock inter-
I am concerned about flow-field steadiness in boundary-layer
G. Settles: actions.
We never see perfectly steady fl..'"
criterion
by which we could
judge the flow
in rhe free stream.
there some
Is
end does Case 8651 meet
steadiness,
this criterion? C.
However,
steadiness.
and
sepa-ation
Whenever
Horstman:
reattachment
are
confined,
not
although the separation Is unsteady,
one
sees un-
the 3hock position is
steady. K. Owen:
There are large-scale motions for unconfined separation in almost all exper-
iments. This large-scale unsteadiness will lence quantitie.s. A.
Favre:
How was the Reynolds-stress
component
influence the measurement of turbu-
measured?
We measure it
with cross
The
uncertainty
wires. C.
Reynolds
The
Horstman:
itress was
measured
with a
"V" wire.
obtained was within 7-8% of the integrated velocity profiles upstream. Flows 8600 and 8690 Cases 8601,
8602, and 8691.
M. Firmin:
What are the two-dimensiotiality checks on the airfoil experiment?
M. Rubesin:
Oil-streak
flowgraphs were used.
There was only a one-inch section on
each end of the airfoil which wa$ not two-dimensional. R.
Melnik:
field surveys could be made rather flow to
Perhaps flow-
One should really have a better test of two-dim isionality.
simply
tunnel wall,
the
look
flow is
no
longer
It
than oil flowgraphs. If
two-dimensional.
a shock wave
not enough for a
is
interacts
with a windfor both the
This applies
two-dimensional.
airfoil and the Kooi experiment.
495
. .
.%' .
..
.
.
.
. .
M. Rubesin:
Calculations were run for the Knoi experiment. but
agree,
was consistent with other known
the disagreement
perimentR.
It
The results did not quite
was concluded
that
two-dimersionil
effects are
three-dimensional
not
too
ex-
(:erious
in this flow. R.
Melnik:
the
Wan
wave?
It
shouldn't be if
M. Rubesin:
Yes,
J.
I
Viegas:
to
downstream assumed
pressure
be
tho
behind
pressure
shock
the
there are three-dimensional effects present.
the downstream pressure was used.
have
used
the
downstream
pressure
in
my
experiments,
and
it
has been
i.
The geom-
satisfdctory. H.
McDonald:
I
etry
the
2.
of
Mesh
question the use of
definition
"important
for
In
agreed
S.
This is
Bogdonoff:
Is
the vicinity
flow.
8601,
this
ered ab a tube M. Rubesin:
a special
3.
of
Since
flow for three reasons:
mesh generator
the
this
leading is
edge
not a
in order
to be
seems
be
practical
the calculation
interaction
flow or can it
of
needs
to be made
a shock with a
be represented
in
the shock really standing
Data in
measuring
airfoil
design,
it
boundary
layer
should
by a two-dimensional
It
is
be consid-
flow?
a tube-flow case.
explain the three-dimensional Marvin:
particularly
a circular duct.
still
in
the tube
flow of Kooi?
as though it should be an unstable (unsteady) configuration.
J.
to
computed.
tc, find funding for the computations.
Case
that
in
this
will be difficult
"G.Lilley:
require
flow wIll
the McDevitt
it
looks
Gould thiE possibly
effects?
the experiment v.ere obtained by slowly moving the shock across
instruments.
Static-pressure
the
measurements did not show any significant
"large-scale movemea&~s. M. Rubesin:
I
doubt that computations will be
ter of shock waves.
"S. Bogdonoff: In
It
to handle
usually gets smeared out in
I am concerned with problems
my experience,
able
in
the high-frequency
jit-
these schemes.
stabilizing
the position
of the shock.
I've had trouble doing stabilizing normal shocks.
Further Discussion on Flows 8650,
8600, 8690
8660,
Case 8651 The Conference
* ever,
that this
is
agreed to recommend
Case 8651
a special case relating
as a
test case.
to a high Mach
It
was
noted,
how-
number flow with relatively
high uncertainties.
Cases 8661, After
8662, and 8663 lengthy
Conference without ,,..<
-
discussions,
all
three
of
the above
cases
were
recommended
further comment.
.,*496
..
......
by the
I
_
Case 8601 Based on questions
The Conference agreed to recommend this flow as a test case.
that were raised in the morning session and the past experience of the committee memdiscussion concerning possible unsteadiness of the shock
bers,
there was considerable
wave.
When queried about this, however,
the experimenter stated that information from hot-wire signals)
(surface
high-frequency instrumentation
showed that the shock posi-
tion was indeed steady. Case 8602 However,
The Conference agreed to accept this experiment.
its summary and speci-
fications need to provide a clearer description as to the exact nature and type of the flow. Case 8691 This both in
flow was
"seems
However,
Conference.
by the
were
questions
raised,
the morning session and at the evening committee meeting about the possibility
of three-dimensional
*
recommended
effects
in
The available experimental evidence
this experiment.
sufficiently two-dimensional to make this a useful
to indicate that the flow is
test of turbulence models and computational methods.
!
. .
..
..
%
.
497 -
.- ;-
- '~.-
..
~
.
*
~
-
-
-
~
L--
.
~
.
.
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPRESSIBLE Flow 8650,
M. Kusaoy and C. Horstman
Data Takers:
fICTORIL• Plow "SO.
Data
Kl..1.tairs
Horatman
M. Rubesir, and C.
Data Evaluators:
Case #8651;
ILIAIT A,1uy•smtri
H. IbsmeIa and C. Horetsiss.
N.ba4r of StalO•ts
Shock Impi.4oa.
n. (owparsotlc).*
I•t&..ur
Va"" T-1b.4 Fi lle
veiculy dp/du
!r
Z.. Ott-. .2lsst..trY o
C9
geus User
ii|l
V
or
Test RIt
Cas.
"l[ torJI •:,P'.gt
Pr O
r-
C.
A
-
S.....1-
-
-
It~
1
SI._J_9
*
U
ote
W_
lot "St . lost J. 4,T_ i t o (b...1 0 . 6o)
oO.. C. c.d o.. Aa
7.2
l -
a.. tMrad.
tst..~trassterlasV e *set Ie
___
"atoed
Comment s
Plot
Ordinate
Abscissa
Range/Position
1
pw/p.
x
0.2 < x < 0.90 m
.1
J'.
0 < Pw/p._ Cf
2
Wall-pressure distribution.
< 10 Wall shear-stress distribution.
0.2 < x < 0.90 m
x
Cfc. - T,/1/2 P.U
-0.001 < Cf< 0.005
4 curves
0 < y < 0.035 m
U/Uy
3 .
x -
-0.3 < U/U.. < 1.0 4
y
0 < p/p.
0.70 m.
0.425,
0.20, 0.33,
4 curves of density profile at
_ 0.035 m
p/p.
-f velocity profile at
x -
< 5
0.20,
0.33,
0.70 m.
0.425,
Special Instructions:
This
test
axisymetric
case considers
boundary layer on the outside of only one case
cases are on the data tape, ator)
the interaction of an axisytametric shock wave with an a circular
(the separated
cylinder.
Although
two test
case with a 150 shock gener-
is to be calculated.
"498
)I'i
"
- -
-
-A-- -
'
•
•
-
•
-
•'-- - •:
•
- -
•
- - -•
•
•
. •
•
" _ "
,..
zw,_,,
• •,:
.,'"._
_
i.I PLOT 1 CASE 8651 FILE 18
:=-9.
%:
~7.5
5,0
L
I'°60'-.0
*
0
0.0 0.
PLOT 2 CASE 8651 FILE 18
%.
0.004
0
0.002
0.5
i
vC9
.•!,=
9
x (M,)
"•-,0.002
-00
Q
0.000
0
~0.000i•
i-
0
'• -2;i
0.5
= -'= •
"
x (n)
.-
_
r.
..
. 4
.
.
.
.
.
..
.
.
...
.°
"".
499 .
,*
".
71.-.1
7
.1:
f
,T
19,22,25,28 FILES 8651 PLOT 3 1--CASE -I I I I -• tI
x
0.2tm
0.33
0.03
-
o ;-
040
0
0.425
0
-o0'0 0i"
0
g--,
.0
-
0.70
0
0,
0+0
I0 0
0.02
+
tq
o~
/
+,.1 e,
00 0
0~
0
0
1
3
1
0.00..
o
I .-. ~ ~~~~~0.04
;'"
x''
1
-"
0.2 m
0.33
"-l
0
±
0
I..
0.00 ..
""
I
0
00
(0
p/p-
0
,,.;""0
,.
'0.70
.
..
1
'
1
I
I-4
0
0 5 0
...
I
0.4•25•
°
0
".',
g
.0 0
t-',_
""0
o
PLOT 4 CASE 8651 FILES 19,'r,_2, 25, 28
0
•"000
"
,
I
1
5 0
o-
50 5 0
5
p/p-
L44
500
S~~~~~................................
.. •...._...•.
..-.
.-........-.
,•....
. ........
,
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPRESSIBLE Flow 8660, Case 18661;
Data Evaluators:
M. Rubesin and C. Horstmin
D. Peake
Data Taker:
,zCrcw.SUAIY 90= Vivow 04.
Date gwsortfs
NM. abs.L.
mad C.
wU--C 0memlo I Neck
k.:z,
Of3O"•
I
ý~
1--ted. LUISI&3
(Oks04
•).
r-
ot
,,
V-
Cp
thr-r 0otse.
Cc
It_
CA 666
_
pros- probe (hboed D.Ps A o)
Ordinate
Abscissa
Range/Position
pw/pso
x
0 < x < 0.07 m 1 < Pw/po. < 1. 6
2CfL'/CfxO
0 < x < 0.
07
_~
2
Coments
m
o <_ lcl/Cf •
tt_
_
~
k o i 1...on. V kowe Is term of U sd flow &s"I*. "
D. P MOt
Plot
i
____
O
or
MA_ oommstry
SToot Dat. Taker
.L
Morstam.. 10416o
-__--..,~
"
1.0
Wall-pressure distrlbution along y - 0.0254w.
..
Surface shear stress, Cf..o is
I"A
the surface skin-friction coefficient on the wind-tunnel floor at an x station corresponding to x - 0 (the leading edge of the wedge). Along y m 0.0254 m.
z.O
3
Surface shear direction along
0 < x < 0.07 m
x
(deg.)
0 < oizI..O. <400
y -
0.0254 m.
alz0
4
U/U.
/au
tan-lj(T)
0 < z < 0.07 m
4 velocity profiles in the x-z
0 < U/U_ < 1.0
plane at
y -
0.0254 m
0.009, 0.0236, 0 < z < 0.00"i m
5
-"
0.0523,
at
x -
0.0643 a.
4 curves of flow angle a for
0 < a < 400
y -
0.0254 m; x = 0.009,
0.0523, Stn- t
..
0.0236,
0.0643 m. (V/U).
501•
.j • .
.
-
.
.
.
.
.
.
.
.
..
..
..
.
.
.
.
.
.
.
.-
1-
"Special Instructions: Thig dimensional
test
case
considers
boundary layer.
conditions have been specified at
x
-
0
,
a
of
interaction
the
One test condition is
skewed
shock
to be computed.
wave
on
a
two-
Upstream boundary
I
corresp,,nding to the wedge leading edge.
.I .
PLOT 1 CASE 8661 FIL11, 2
Im,. 1.4 "-oi
--
/,.p
-'-
t.2 L
:. 0
C5
o 502
I
PLOT 2 CASE 1.0 L
'
T
".'
0D 0.4
0-.0
;3
r-
0.8
,
)
0
0.4
'r
0.5
0
0
0
00
x
.0,
(in)
PLOT 3 CAS:E 8661 FILE 2 30x
W
200
__
•
F..
~(deg)
.
10
.
0
()0.0
503
.
.
.
.
.
.
.
.
.
.
.
.
.
-..
C%
P L OT 4 C AS E O O'
x
0? oG
x
-
0.009
m
0.0236
_
i09i 0
0 .0523
0 .0643
"0
O
0". 0
GC PLO
5
CAS
_J
_
i7
i
o
*
7-
o. ,
P, KES
;,)
0 866
0
,
'2 ,G
F,,S34.,
,
I-
*
&
0.00
x[
0. 00
-
--
'
U
"<"
,
~ooooaao
.
I 0
'
t
"~~n
-
0
-
10.7
r)5
10-3
o
T
0
- o T
o
00 00[
"""~~
w
m
I 50
0.000
,
.1
"
CI-O
o
o
O0
IJ
504
O0
"
i
* .
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPR!SSIBLE Flow 86'60, Case #8663;
Data Evaluators:
Data Takers:
Fpootua.
Cone bet Tko
C.
gets 9£oln4tog.
H. Xussoy, .J.Viegas and C. Horstman
ii.als~si.an
Test Rig Oomemtry
C,
orstme
V
c. 6-Totass.
WI
'ThrG.-stnGnlodt
I
2
f
L
n
to
t
(tker Wt..
6)ltn.it~
to vtnd.&Ad .ovmrd Plaesw.
10"
..
d
Ordinate
Abscissa
Range/Position
P~,/P.
x
0.06 < x < 0.28 m
Wall-pressure distribution.
0.5 < pw/pasj2. 5
3 curves at
0.06 < x < 0.28 m
Wall shear-stres8 distribution.
-rW
T
x
-0.5 < \,./Ti,
<
Comments
.5
a
-)x
0.06 < x < 0.28 m
(deg.)
h'
0
y
u/u.
a
tan
Y.O
0 < y
6 cm.
x -
0,90'. 0% 1800ý
/ ay1 y..01
{-l
=450,
Velocity profile at 4 curves at x -0.06,
IY.y0, 90%, 135'. '
0.12,
0.20, 0.26 m 5
y
/K/U..
0 < y < 0.04 m O < V'K/U
< 0.1
Turbulence kinetic-energy profiles at x
6
/.m
0 < y < 0.04 m -0.0003 < r/pooUw. < 0.0008
505
L
Surface shear direction
3 curves at
4
0 or00, 90*, 1800.
evaluation at
Tf
3 curves at
-4
3
Shockp.t"I64mbt (a..PSr,.nt).
o~~
.iUv~
t
Plot
M. Rubesin and C. Horstman
-
*-00.
4 curves at
0.06, 0.12, 0.20, 0.26 m.
Turbulence shear-respfie at
x
0
-
-0.06,
00.
3 curves at
0.20, 0.26 m
L
S. .
.. . . . . . . .
Plot
Ordinate
7
y
. . .
. .
.
.
. . . . , . , .
. . -' . .
'
a
0 < y < O.OA M 0 < a < 40*
(deg.)
. . . . . . . ....
. . ..
'" .
.- - ,
-•
.
.
Comments
Range/Position
Abscissa
-
Flow-angle profiles at $ - 90*. 4 curves at x - 0.12, 0.15, 0.20, 0.26 m.
a - tan- (W/U).
Speciai Instructions: Thit test case cncnsiders the interaction of a skewed three-dimensional Bho, with an axisymmetric boundary layer inside a tube.
PLOT 1 CASE 8663 FILES 24,6
2.5
.
I
-
I.;
8o-
* g90o
00
-I" ,O
T
/p
..
0
0i
00 0
0
0
1.01
0
0
0.2
0K2
0.40
x (M)
.12i-i:506
"wave
GjV
-PLOT 2 CA SE
900
0.
F~
1.0
35:333 711-1L-S 24, I800
'
~
0i
I
-0.5,
C,
0
.01
o0<>
0.2
0
0.2
0
'
0.2
0
0 >C
-- -
. 0 i
.: ' ;,k :. )-
PLOT 3 CASE 866:3 FILES 3,4,5
150[
I
450~.
135'
90
""M
Wy=O
(deg)I
°° i -.
I
..--
-
-
_**
0
00 0
0
m.w?
0
n, 2
0
7-1
.,.
"50-
0.075
"
FiLES 7, 4 -:A: ` 8363 PLOT , /Ii',r I
I,
m
F- x -0.06
0.1.2
-r
-
0.050
0.025
I. L
T I,
.ii
f.
I
01
0.000 Lo
0o.26
0.20
-7
1
:
01
0
10
0
1
F4.
PLOT 5 CASE 8663 FILES 37,38,40,41 x,>-0.06
m ,,
0.04
-
S0 S0
0
o
0.02;-L
0
4
0
0
L o
"1 0 0
4
o
I
0
F-
0
+
0
•'
+
0
0
0
0
i.J'--
0
-
0
-
.'' 0,-'
.'
0
0
0-.,.'
'
0_
°00
°
S".
0 9
•'
0
1.
,
"
0 0
,
•
0
.
0
1" 1.
S
0.26
'
-' 0
O
;
0.20
0
-0 S
f
0.12
00
0
0
.
o.
,0
•-
0.00
0
0.i
0
0.1
0.
0
0
0.1C
508
.•,=..•__,.,__-
•
-- ."
.
- .
.
.
-
I
PLOT G3C-AS"E E-63-3LS3~,ie4 0 -0.06
0.26
u0.20
0.04
-
0
0
0
0..00
0
0
000
0
.0050
0Q
0.2
0.2
0.
)'
0.12
o
0.04
001
000
o -%
0
~0.00I 0
0
0.005
20
40C0
20
509pU
4
0
200
40
FOR COMPUTATION
SPECIFICATIONS
ENTRY CASE/COMPRESSIBLE
M. Rubesin and C. Horstman Data Evaluators: G. Mateer, A. Brosh and J. Viegas
Flow 8600, Case #8601; Data Takers:
rvie
14W0.
DEa C K v&
ltor*
H.t .
U
.i.nh o
and C. mort.tao .
Lotercttoa &t Tre.onlc Spoeds..
"Lepiagod Mornel Shock Wave-goud4ory layer
nMuber of St.tios. IqMeasutred Thrbolit.e
Velocity
Toot all
cat.
Y r A~~RGhr
dp/da Or
be.1~rG.etjC,
I
r~otti..
other Hot..
K..
.
.
iI
Azleoynowtrl¢ grofl),o 64L& (r One tolt cort"t',*. t
Case "14O
C"....'G°l
-7irl
*
.i.
,-
-
II
4.
I
to
I
?lot
Ordinate
Abs:issa
1-7
p/p.
x
oI
ri.
__
___________-
I
--
...
Comments Wall pressure distribution for
< x < 20
1 < p/p. < 2
each of 7 test conditions;
see
instruction 1.
8-14
Cf.
x
-2 < x < 20 0 < Cf. _0.0022
15
y
U/U.
0 e y < 0.10 m
,
S16
y
-o
UlP•U2
-0.002
Skin friction distribution Cfoo or for each of 7 test t'.U2 conditions; see instruction 1. Velocity profiles for test condition A at 0, 4, 8, and 16; x/6. see instruction 2.
1.0
0 < U/U_ <
<
Shear-bL~ess conditio-
V//P..U2
--
and 16;
< 0.01
profiles for test
'.. at
x/6.
= 4,
8,
see I:.structlon 2.
Special Instruction". 1.
Measurements
were made
for several
Mach
numbczx
and
designated as follows:
2.
6.,-
Moo
3 p.(kg/m )
A B C
1.44 1.42 1.42
0.713 0.182 0.835
1, 8 2, 9 3, 10
D E F G
1.42 1.32 1.41 1.48
2.908 0.301 0.368 0.513
4, 5, 6, 7,
0.0254 m for Case A.
510
Plots
11 12 13 14
'
_)___.___..--___
o,
Range/Position -2
d oIt
Ski n
ti.t sode La. oditto° U werylsa1rl1
1.
6.1O6 (besed
I Plt-
A.lsso tl pro! I).,°L
)'lO4
A. t r Ol ..
Reynolds
numbers.
Cases are
PLOT 1 CASE 8601 FILE 2 UASE A
2.0
" 0000 0
1.5
0
1.0
0
0
75
50
25
x cm.
PLOT 2 CASE 8601 FILE 20
I2.0
I
0
'-1
c0
0
0 0 0
0
CASE
0 0o
I
0
0
0
.1.5
U(
.
1.0 F
x cm.
1 .
..
75
50
25
0 .
.
.
511
.
.
.
.
.
.
.
.
.
11 24 PLOT 3 CASE 8601 FILE CASE C
2.0
0I
000"o 0
1.50
i.4o
.
75
50
25
0
x cm.
26 PLOT 4 CASE 8601 FILE CASE D
"
2.0
1
0
P/Poe I
__________
1.
25•-7
x cm Ply-
1.00
S.
i
.
.
7
............ -...........
-m....--
........
.0
.] 7ý.w .°
PLOT 5 CASE, 8601 FILE 26 "2.
J
I
I
IAIN
I
• 1
2.0
II
P/P1 o
o
5
0 0
0 0
0
1.0 LI
o
1
_
.1
o25
.
_
re1o .
1,
'-i
75
50
x CM.
PLOT G CASE 8601 FILE 28 r
"rr
o
5o o
.
00~QQ00
II
0
1.5
0
so
-')
75
..41
513 *
-..
..
.
-.
-
•...".
.%
?-..4
.2 .1. ..
PLOT 7 CASE 83601 FILE 30 I
°
~
0.0o 0
'
°I
h"
S1.5
0j
t" 4,cf.
I
.
0
2,0
0.02
CASEA
0.000
0
F I
20404
00
I 40
20
0
60
Ccn. xx cm.
PLT
CSE5614
FL
,
I,..,
514.
---- -- -.-
0-0-
PLOT 9 CASE 8601 FILE 21 0.002
o' o~oo~
R
0CASE
0.001
.+
1
0
o4o
[
00
0-
0.000
-
020
40-
x c m .,.
-
PLOT 10 CASE 8601 FILE 23 CASE C
0.002
-
cf. 0.0010
c€. I 0.000
515 00
0
0
00
i:: c
020
-
40
x cm.
515
60
PLOT 11 CASE 8601 FILE 25 CASED
pcf.
0.001
0.000
-].,
h0
20
40
60
x cm-
PLOT 12 CASE 8601 FiLE 27 CAS EE
0.002
"Cf.
L
H.000 [ 0.001
F
0
~
0
00
0000
-
~
.......................
0.000
0
20
40
x cm.
516
60
PLOT 13 CA)E 8601 FILE 29 0.002
Cf. 0
0
0 0
l0 0.000
00
00
00
40
60
X en-.
PLOT 14 CASE 8601 FILE 31 0.002CAS
E
0.002
Cf0.001 .11 00
0.000
0
20
40 x em
517
6c
..
Ij-..
. .. . . ..
....
PLOT 15 CASE 8601 FILES I I " [I
-.-
. . ..
..
5,7,9,15
II
,-
-J16j
o-:t
,-.
,
~0.05I
q 1
l 1
0
i, I I! 1
0
: II
1
0
0
U/u
PLOT 16 CASE 8601 FILES 6,8,14 4 -
V
B
16
o
I
J.*.,18p
, I0
0'l ,i
Q
01
-, 0
u
0
:,
I,
4-
- .,
.0
ol0"."0
001
0
001'"0
-1
L.!
001
Sib
O01~*~
0
*lO00
FOR COMPUTATION
SPECIFICATIONS
ENTRY CASE/COMPRESSIBLE
Flow 8690,
Data Evaluators:
Case #6691;
IICTO'LAL Piat
84100.
8E"l.k torwa
#..bea.i
l•UMMT
Pbret"...
sad C.
W.1.Lifti.4,
of t,
Cd
,
3w
Tot It| oo~try
91;
T•a...Ie
ea ... H I
LAreoIl
vwih 6b6"k-3..retloo..
"....
II--loolowe Fyo I r
Val"",
*
and A. Okuno
McDevitt, H. Seegmiller,
Data rakers: J.
La.
M. Rubesin and C. 1lorstman
or
C
W
V
V
V
Othae.
-,
C1
go
J. Wtivl
Other Sets.
WU
.7Pro,.
A.
-ok
7
-p-
,f
~
.l:::Lare airfoil
0.1iI
.C
Comments
Plot
Ordinate
Abscissa
Range/?osition
1
CPA
x/c
0 < x/c < 1.0
Wall-prewsure distrLbution, CPA - (p - P.)/1/2 P.U2,
0 < y/c < 0.16
4 curves at
AA.4
U/UN
y/c
-2
<
K/U2
3yc
ylc
4
-;-v/UU
_j 1.2
< U/U
-0.5
This large
test
region
of
case
considers
0 < K/Uw. < 0.20
1.0, a,,d 1.1.
0 < ylc < 0.16
4 curvos at
shock-separated
the data act, assume
KIU
the
a,0.75(u+
xlc w 0.8, 0.9,
and I.I.
1.0,
Instructions:
transonic
flow.
0.9,
0.8,
x/c = 0.8, 0.9,
4 curves at
0 < -uv/U2 < 0.05
-
and 1.1.
1.0,
< 1.5
x/c
0 < y/c < 0.16
Special
with
fljw over the
To compute
a
circular-arc
turbulent
vith a
airfoil
klnettc
from
energy
v/U
519
o.
.
.
.
.
.
.
.
.
.
4I
"
I PLOT 1 CASE 8691 FILE 3 00
0
-0.5
00
C
-0
I
0
0-
I
0.9
-1.0
-0.
0.8
0.6
0.4
0 00
":..,
x/c
.
~0. 8
0.9
00
,
0
to
0
,-
1.1
!
0
"011
I .-' ,0
.'
~~PLOT_2 CASE 86391 FI2iS 7,9,11!,13
,°
1
o
0
o
0
0
0
:
I V:-.
520
,,,:,
+""
i.. . -.. ....... .. ..+.."'Y i';" .. .. .." ".~~.. "+-
U/U,• Vo
5
""i .....
.'
•. .
.. .
'
"
. ....
:
i
i. . . i
PLOT 3 CASE 8691 FILES 7,9,11,13 X080.9
1.00
1.
0.2 0
0 0
00
0
0 00
00
0
0/ 00
0.1
T
CO 0000
00
0.25
0
0
0.25
0
0
~000~
0
0.25
0
0.25
K/Um.
PLOT 4 CASE 8691 FILES 7.9,11,13 IK/C
1.0
0.9
-0.8
1 10
S0
0.2
.
I-+0
+0-
Soto
So 10
0
0 0 00
Oo
40
00 00
00
0
00
0 .0rI,{,~0%
0
0.05 0
0.05 0
0.05 0 -.
521
~u
0.05
SESSION XII
Chairm~an:
P. Bradshaw
Technical Recorders: R. Carella P. N. Joubert
Flow 8620 Flow 8670 Flow 8310
"4
. 51
•-;
:TechicalRecoders522i
TRANSONIC AIRFOILS
Flow 8620 Cases 8621, 8623 Evaluator:
R. E.
Melnik 7.
SUMMARY In planar
this
study we
airfoils
to
examined
assess
viscous transonic flow. layer-velocity
available
"
wind-tunnel data
their usefulness
for
for
validating
transonic
theoretical
flow over
methods
for
Only wind-tunnel data that included measurements of boundary-
profiles
were considered
in
this study.
data only very loose criteria could be applied in
Due to the scarcity of such
a:.u'pting data for the study.
All
of the proposed data sets have some shortcomings that iake them not entirely satisfactory
for
the
purposes
of
the
Stanford
Conference.
chosen data sets were the best available
However,
it
was
felt
that
the
for the purposes of the Conference and that
comparisons of theory with these data would serve the useful purpose of focusing attention on possible
shortcomings
of
both the
theoretical
methods
and the
available
data base. SELECTION CRITERIA The main criteria we employed for selecting data for this study involved 'I) airfoil geometry; SAiirfol
(2)
flow conditions;
(3)
type of measurements;
and
(4)
documentation.
Geometry Only airfoil geometries with blunt leading edges and sharp trailing edgea (with a possible
small
trailing-edge
gap)
were
considered.
include airfoils with significant rear camber, critical airfoils, itive
was
thougric
desirable
to
•f super-
typical of the new generatlo.
as these lead to enhanced boundary-layer effects and to more defin-
tests of theoretical methods.
or airfoils
It
with sharp leading
Experiments
edges were
on airfoil-like shaped
not considered
representative
tunnel walls of
airfoil
L
flows In free air and he-ice were not recc siended for use in the study. Flow Conditiona Only
transonic data cers that included supercrltical flows with extensive super-
Ssonic zones and shock wave
were considered acceptable.
We also telt It important to
include cases with variations of sh-oick strength and Reynolds number. *
ted attention to cases with fully attaclied involved complicating features
Grummari Aerospace
cirp.,
bouadary layu!rs as we felt separited casea
that would beat be addressed in
Research Dept.,
We also restric-
Bchpage,
New York
the conferL.n-.
section
11714,
523
-.
:• - - "..- "- -
•.ii.
*-.
-
-
-
"
'
"
-
it was required that the posi-
In addition,
dealing exclusively with separated flows.
.
be demonstrated that a fully developed turbu-
tion of transition be known and that it
lent boundary layer was established upstream of all shock waves. Measurements Only
data
sets
that
included
both
surface-pressure
measurements
and
boundary-
In addition we felt it
layer velocity-profile surveys on the airfoil were considered.
highly desirable that the data include velocity-profile surveys just downstream of the N." "
transition point (and definitely upstream of any shock wave). Documentation It
was
that
data accepted
for
estimates
for
the
primary variables.
Conference
include
in the wind tunnel and uncerdue
However,
2
the
use at
documentation of the experimental environment
complete tainty
important
judgz-I
to
the
general
of
use at
the
the basis of this study two wind-tunnel data sets were finally recommended
for
appropriate
ddta,
one
data set
(DSMA
5 3s airfoil)
was
recommended
for
lack
Conference with only minimal supporting uncertainty assessments. PROPOSED DATA SETS
"On
use at the 1981 meeting. in Cook et al.
These are for the RAE 2822 and DSUA 523s airfoils documented (1979),
and Spaid and Stivers
(1979)
tained with rectangular
The data were ob-
respectively.
wings of relatively high aspect ratio spanning a wind-tunnel
test section of solid side walls and ventilated upper and lower walls. chord ratio was 4 in both cases.
-.
The height-to-
The DSMA airfoil had an aspect ratio of 4; the RAE The airfoil sections were all rear-loaded supercriti-
2822 had art aspect ratio of 3.
'-al types leading to substantial boundary-layer effects. CASE 8621. The
"tion.
RAE 2822 Airfoil (Cook et al., R;E 2822
airfoil
The conditions
the following table.
is
1979)
moderately rear-loaded,
for the test cases recommanded
12.1% thick
supercritical
sec-
for the Conference are given in
All tests, except Test 1, involved supercritical flow with shock
waves.
"RAE 2822 6
Test Number 7
9
0.676
0.725
0.725
0.730
0.730
2.40
2.92
2.55
3.19
3.19
.7
6.5
6.5
6.5
2.7
0.03
0.03
0.03
0.03
1 M. Geometric angle of attack
a
(degrees)
"ReX 106 x/c transition
0.11
12
524
-x
•-
Boundary-layer velocity profiles determined from pitot-tube surveys are available only Skin-friction and boundary-layer integral paramon the upper surface of the airfoil. eters were determined from the measured velocity profiles. Significant features of these data are: 1.
The data include a range of shock strengths and one case tested at two Reynolds numbers.
2.
data included a measuring station just downstream
The velocity-profile
of transition that demonstrated
the establishment of a fully developed
turbulent flow. The data appear useful as a free-air simulation with wall effects that
3.
are small and correctable. original
documentation)
Blockage corrections are estimated (in
to
vanish
and
downwash corrections
based
the on
linear theory are provided in Cook et al. (1979). CAST 7 (Stanewsky et al.,
1979)
The CAST 7 airfoil is an 11.8% thick supercritical airfoil with a small trailingedge
thickness equal
2822.
to
tTE/c
- 0.005
and somewhat more rear-loading than the RAW for the conference are given
The conditions for the two test cases recommended
flow with shock
waves.
Velocity profiles were determJned on the upper surface from pitot-tube surveys.
Skin-
in
the following
friction
and
table.
Both
boundary-layer
cases involved
integral
supercritical
parameters
were
determined
from
the
velocity
profiles. DSMA 523s
CAST 7 Case Number
2
1
2
3
0.766
0.785
0.60
0.80
0.80
a. (Degrees)
2.5
2.5
2.6
1.8
2.4
Re x 10-6
2.4
2.4
4
2
3
x/c Transition (Upper)
0.075
0.075
0.05
0.35
0.35.
x/c Traasition (Lower)
0.075
0.075
0.18
0.18
0.18
Mý
.
Significnt features of the CAST 7 data are: I.
are for two supercritical
The
data
and
(geometric)
0.785.
flows
at
the same Reynolds
incidence at two different Mach numbers
These conditions resulted in strong shock wave
number
M - 0.765 and (MlocaI
- 1.30)
.
-
but fully attached boundary layers in both cases. 2.
The
velocity-profile
data
included
transition that demonstrated
a nonsaing
the establ..
station
downstream of
ient of fully developed tur-
bulent flow.
3.
Fairly complete documentation
"
.
is provided in Stanewsky et al.
(I"9...
525
IL
DSMA 523s (Spaid and Stivers,
CASE 8623.
The OSMA 523a airfoil is
two
tests
with a traversing
the airfoil are given in the
i) was subcritical while the other
= flow with relatively strong shock waves (M local profiles were determined on both the upper and local surfacea
supercritical
involved
Boundary-layer
1.25).
The test conditions for
The lower Mach number test (Test
following table.
airfoil
11.0% thick supercritical
a modified Whitcomb
rear-loading.
with significant
1979)
pitot
integral
and boundary-layer
Skin-friction
tube.
parameters
were determined from the velocity profiles. DSMA 523s 1 M. Geometric angle of (degrees) attack a Re x 10
6
Test Number 2
3
0.60
0.80
0.80
2.6
1.8
2.4
4
2
3
x/c transition (upper)
0.05
0.35
0.35
x/c transition (lower)
0.18
0.18
0.18
Significcnt features of the DSMA 523s data are: 1.
The
data
set
two
include
difficult
supersonic zones, strong shocks, velonity-profile
The
'.
data
cases
supercritical
with
large
and large viscous effects.
included
a
measuring
station
between
the
transition strip and the shock uave that demonstrated the establishment of fully developed turbulent boundary layer. 3.
velocity-profile
The
surveys
included measurements
of
the profile in
the "cove" region on the loser surface of .ie airfoil. The data analysis included a study of probe-interference effects.
4.
-RESERVATIONS/PROBLEMS WITH THE DATA The
main
reservations
in
using
the
associated with uncertainties due to (i)
proposed
data
sets
for
the
Conference
wind-tunnel wall interference and (2)
are
pitot-
"tube interference. The main effect of wind-tunnel wall interference,
if
it
is
small,
is
to introduce
(hopefully) small corrections to the free-stream Mach number and angle of attack. magnitude
of
the wall
height to model chord,
"with
h/c - 4
corrections h/c.
In
in both data sets,
suitable
for velocity-proftle
expected
to be
significant
is
most strongly
the tests reported
by the
ratio of tunnel
large models were employed,
in order to provide thick boundary layers that were
me.surements.
in both data sets.
526
L_.......-
affected here,
The
Hence wall-interference
effects
can be
Blockage and downwash corrections
to
both the RAE 2822 and DSMA
the free-stream Mach number and incidence were provided in 523s airfoil
estimates
theory
an
from
results in
the
are
and
not
airfoil
the order of suggested
the
by
the
comparisons
with
distributions
in
computed
the
the
shifts
the
that
Thus
it
is
larger
much
that
for
data
and probably of
corrections
blockage
Mach number
DSMA 523s
the
may not
that
methods In
use
the
free-
the effective
in
for
surface-pressure
measured
uncertainty
this case,
be
2822 data w.11 be
the RAE
only
appears
in Mach
Similar comparisons for
to have only small influence on the
can be expected
Since these conclusions are based on comparison with only a single
results.
theoretical
of
The DSMA 523a data will likely only be useful
the computations.
stream Mach number and incidence
ef-
with
consistent
indicate
the interference
The relatively large correction in
conditions.
boundary-layer-type
with
are
theory
indicates
comparisons
useful as a free-air simulation. comparisons
at
theoretical
The magnitude
and correctable.
wall interference
are required.
free-air
to
small
that
to achieve agreement with data.
suggest that
LM - 0.04
correctable
are
corrections
duwanwash
The
correctable.
different effects
data with
the
of
suggest
method
boundary-layer
required
number and incidence the DSMA 523s
wall
wind-tunnel
comparisons
Preliminary
unknown.
2822 experiments
blockage
estimated
of
airfoils
similar of
assessment
quantitative
interacting
RAE
on
beyond the state-of-the-art and the accuracy of the simple-linear-
is
speeds
transonic
fects
the
Unfortunately,
sizes.
data
to wind-tunnel
solutions
interference-theory
..
of linear-
The estimated corrections were based on empirical fits
teaLs.
they shold be regarded as
method,
to be re-examined
tentative,
as part of
the work of the 1981 Meeting. The
of significant
other area
of probe
interference
on
the
alters
parameters.
Although
effects of on
probe
results
(Spaid
and and
ence
involves
problem
have
boundary-layer complex
remains a significant
and
influence of a
The presence
inferred
the
to develop
attempts
rough
have
developed
been
buundary-layer
estimates
for
the
Simple estimates based
suoh estimates are not reliable.
for
the
DSNA
523s
test
which indicate effects of the order of 5-10% on the
1979),
integral
flow-field
nonuniform
the simple theory.
source of uncerr''nty
in
the actual
However,
parameters.
three-dimensional
for in
are definitely not accounted ence
been
approximations
Stivers,
skin-friction
from the
measurements.
profiles
velocity
measured
there
flow
arises
the data
layer induces an increased adverse-pressure gradient that
interference
two-dimensional
in
the boundary-layer-profile
pitot probe in the boundary significantly
uncertainty
interfeiwhich
effects
The effects of probe interfer-
the present
a situation that
data,
Is not likely to be improvee in the foreti;ý,ule futk~re. Other
potential
problems
with side-wall boundary-layer diuturbance on the
forward,
with
the
data
of
less
a
serious
nature
are aesociated
effects and with the appearance uf an ;',omalous pressure The rapid growth
upper surface of the RAE 2822 airfoil.
527
.............................
.
..
.
.
.
.
.
..
.
.
.
"of
the
side-wall
boundary
layer
in
the
vicinity
of
the
airfoil
introduces
three-
dimensional disturbances into the flow that can have a significant effect on the measured characteristics of the airfoil.
The effects are not well understood,
be corrected for with existing methods.
"by
the
ratio
Because study,
of
of
the
the
large
this effect is
nesses of
the
side-wall spans,
The side-wall
beundary-layer
(S/c
-
3,4),
effects are controlled mainly
thickness
employed
in
boundary
layers
were
not
to
the
not expected to be significant.
side-wall
and cannot
the
tests
span
in
the wiig.
considered
Nevertheless,
measured
of
in
this
since the thick-
the experiments,
this
effect will remain an area of uncertainty in the data sets. All
the
supercritical
cases
of
the
RAE 2822
data
show a very rapid
expansion
followed by rapid compression near the leading edge of the upper surface of the airfoil.
A reason
pressure
for concern is
distribution
that this very noticeable feature in
does not appear in
theoretical
solutions.
the experimental
The
pressure
over-
shoots occur near the upper-surface roughness band and one may speculate that they are caused by disturbances induced by the roughness strip.
In the absence of more defini-
tive information this effect will remain a source of uncertainty in the data. SUGGESTIONS FOR FUTURE EXPERIMENTS On the basis of the present study the following advice can be offered to experi-
"mentalists planning 1.
There is
"at
further airfoil teats:
a continuing need for a careful experiment on a planar airfoil
transonic speeds
which includes measurements
sure. and velocity profiles. a
*
significant
measurements .
surements
2.
3.
4.
-
.
--n
Since it is known that the wake can have
section
characteristics,
should include detailed
the
surveys of the near wake and mea-
effect,
should
supercritical
be
boundary-layer
of the pressure variation across the boundary layer and wake
near the trailing edge. In order to emphasize the boundary-layer an
aft-cambered,
rear-loaded
the airfoil geomatry airfoil.
The
airfoil should be closed at the trailing edge to simplify the theoreti"cii modeling of the flow. The transition point should be fixed as in the experiments of this study and
0
effect
of both surface pres-
velocity-profile
surveys should
stream of the transition strip. The effects of wind-tunnel-wall
include stations
interference
is
just down-
the main area of con-
cern in the use of wind-tunnel data for validating theoretical methods. Small uncertainties in the effective free-stre'm Mach number and angle
"of
attack ace the main source of uncertainties
evaluation of theoretical
methods. 528
If
tieat prevent a clear-cut
they are to be useful for code
validation,
future tests must provide for a careful assessment of wind-
tunnel wall interference and
downwash
corrections
computations. tests on
This can,
similar
contouring
and an unambiguous that
perhaps,
airfoils
the walls
should
be
statement of the blockage
employed
in
the theoretical
be achieved by carrying out repeated
with various
to eliminate
the
chord-to-height interference.
ratios
or
by
The pressure on
the upper and lower wind-tunnel walls should be measured for possible use in
theoretical codes that can employ this information in the sound-
ary conditions. 5.
If
feasible,
the boundary-layer
surveys should be with a laser veloci-
meter or other nonintrusive devices to avoid uncertainties due to probe interferencd. 6.
The
thickness
of the
side-wall
boundary layers should be measured
in
the flow from this source should
be
the experiment and the effect on assessed. It
is,
of course,
be very expensive.
realized
However,
that an experimental
program along these lines would
to be useful for code validation it
the above points are important
and should be addressed
in
is
believed that all
future airfoil tests aimed
at filling this role. REFERENCES Cook, P. H., M. A. Mcrjonald, and P!. C. P. Firmin (1979). "Airfoil RAE 2822 distributions, boundiry layer and wake measurements," in Experimental for Computer Program Assess• it, AGARD Advisory Report No. 138. Spaid, F. W., and L. S. Sti'erh, Jr. (1979). measurewent3," AIAA Paper No. 79-1501.
-
pressure Data Base
"Supercritical airfoil boundary layer
Stanewsky, E., W. Puffert, R. Muller, and T. E. B. Batemen (1979). "Supercritical airfoil CAST 7--surface pressure, wake and boundary layer measurements," Experimental Data for Computer Program Ascessment AGARD Advisory Report No. 138.
529
|'
.
DISCUSSION Flow 8620 The definition of by R.
Melnik was
"sharp trailing
edge" was queried
that a "negligible trailing-edge
(U. Mehta).
thickness"
is
The answer given
anything
less than the momentum thickness of the boundary layers at the trailing In
the
evening
conditions, Attendees .'
Firmin, and
and
P.
Bradshaw
Humphreys,
R. E.
the
main
inaccuracy
numerical
were:
D.
discussion,
topics
in
the
(Chairman),
Melnik,
E.
G.
P.
were
tunnel
R.
edge.
interference,
part
of
the
Carella,
F.
Dvorak,
"inviscid-
Brune,
significantly
starting
calculation. M.
C.
P.
Sutton.
It was resolved that the CAST 7 case should be deleted on grounds of excessive uncertain interference (2-degree corrections to an cA of 2.4 degrees). The RAE
2822 case has a much smaller interference. Computors .
get
-
the
quoted
encouraged
*
are
recommended
lift
to do
to
run
coefficient;
further runs,
the
the
actual
nominal Mach a uied
number
should
and
to adjust
be quoted.
a
Computors
to are
varying M to optimize agreement with shock position or,
perhaps better, with lower surface-pressure distributions. Pressure __
=
pressure,
distribution
should
be
plotted as
should
be evaluated
(I) in
gral of sucface pressure and surface In
boundary-layer
sition point the
turbulent
should
p/P_,
where
to simplify comparisons between these different
Drag
*
at
be and
(trip
region).
plotted as
an
increment
to give a
Boundary-layer (P-pw )/2/(Pe-Pw
of
profiles )/2,
C at
the
This will reach unity only in
•[•
function of y in the form of the usual pressure coefficient skin-friction coefficient Fhould be plotted. distinguish
and
RAE 2822,
between
numerical computors,
shock wave).
errori due of
whose methods
to
give
as an
the wake
total
inte-
number NM_ should be
a
*'."
real flow for the highest Mach number
!ase.
(Ed.: This recommendation has requested by the data evaluator.]
been
nor
530
condi-
y but different _p_)1/2
(p-p-.)/(l/2pýUo_ 2 ).
model
external-flow
number equal
followed;
(in
parameters wall
(p-p-)I/
(or
shear-layer
solutions the
we
inviscid
viscous flow.
trailing edge should be
shock Math
tran-
Pressure should be plotted as a
ordinat-s as for the fuW1
-4-•
of
the
profile
w denotee
plot
should calculte
the
applied at
independent
the turbulence
allow it,
pressure near
,'sed to
In
compressible
(measured)
regular
(nearly
the absence of a shock.
inaccuracy
using the same
Kutta coneition of
any
(2)
measured
the subscript
-
of
be
first
upstream
and downstream
and
for evaluation of integral
where
conditi)ns
6 should
-
that all
denotes edge
match
in
tions
rics)
e
downstream,
_
fo
subscript
fa-
the upstream
shear stress.
calculations
posirion)
terms of (
P_ is *
cases.
to
that
computations
used,
nume-
recommend
flow around The usual and a Mach
occurring
request
Local
in
(p(x/c)
the
cs
I SPECIFICATIONS FOR COMPUTATION CENTRAL ENTRY CASE/COIJ'RESSIBLE
Data Takers:
P.
#62o.
PICTOSIAL SuiOaIY oat& gvaivtori it. t. newi|* T
~
~
~~IV. lu Io:|ty i
dpId.
1 CPlo
Data
-I&
T
ate
I/ me
Plot
~tfoi
lAS2122
Ordi
t
2o2l
-
v,,I'|*'.: rotI..=
Tburin|.
t•
I -t
A"21
erI
R1o.
vo
I
-
t .. --
0/c
x/c
0 < x/c < 1.0 < 0.02
0 < X/c < 1.0 0 <(H < 5 0 < X/c < 1.0 0 < Cf < 0.006 x/c
s s
0 < x/c < 1.0
-1.8
< -C
< 1.2
K.othe
~
Ikol , ft. Notes
Am
.4to 4 .g 4 l 11esponD 0.7)01 oh... of boot.r,-leyer to..r-l p~rem lter.
on ChardI
t/o 2 ,9 Comments
,6
_
St. o3;
u La.e
___________ _L..EZJ 0
7 k.
CC 111-4
the
.2T 0,: I Range/Position
xc
Other.&
Wall
Abscissa
2-H.X/c
-,V
ert 01 P,..
..0
e
I
I
o
I
<
I x/, II
-Cp
l.
orA
Case
P1~e
3Cf
Aro
Kt.eo-d-
V
Ordinate
t-1
r, ln.
of st~lot o
mumbe
i
2822 Airfoil)
M. McDonald and M. Firmin (RAE
Cook,
r•,w
R. Melnik
Data Evaluator:
Case #8621;
__
5 curves
corresponding to
Tests 1, 6,
9,
7,
12.
5 curves corresponding to
-Cp
x/c
-px/c
5 curves corresponding to Tests 1, 6, 7, 9,
12.
1 curve of upper and
lower
surface pressure for Test 1.
6
-C
x/c
0 < x/c < 1.0 1.2 -1.8 < -Cpi
1 curve of upper and lower surface pressure for Test 6. Negative Cp plotted up.
-18.. 0 ( x/c
1 curve ofrsuefo srae upper and lower et7
-Cp
x/c
< 1.0 12 1p
0 < x/c < 1.0 -1.8
7
-
< -C
< 1.2
0 < x/c < 1.0 -1.8 < -Cp < 1.2
A
Tests 1, 6, 7,9, 12.
Negative Cp plotted up. 5
I -,
-<
Negative Cp plotted up.. 1 curve of upper and lower
-
surface pressure for Test 9. Negative C plotted up. 1 curve of upper and lower surface pressure for Test 12. Negative C plotted up.
531
I-
Special Instructions:
I
Category
Category TI u Dmination
following
the
of
either
in
computations
submit
two
used on output graphs:
indicate which is
categories;
S~
to
invited
are
Participantu
calculation
A boundary-layer-type pressures.
-
A complete solution of the problem including of the surface pressure.
surface
measured
the
employing
-
the theoretical deter-
Input Data
of
values
'not:ad
sps-ifi~d
Of
the
ot
angle
the
be
initiated
order
in
atLack
the Category
in
'
dlude all
measured surface-pressure deficiency
caused by tunnel-wall the experimental
-
than
.
corrections.
in
that results in
all
cases,
(or a
*i.
Mach number
is
*
rected as follows:
the
uncertainty
in
Category
II
Therefore, are
Mach number
experiment. should
distribution
the effective Mach
In in-
number
type computations at other for blockage
to allow
as an attempt
acceptable
shock position on the upper
in
the results must
C
LA
2
at
life
and
2 /M
experimental
the
If
could not be done).
pressures
the experimental
surface of the airfoil.
include computations
also
clear statement of why this
shifted,
the
are encouraged to find the value of free-stream Mach number
best agreement
Mach number
is
interference.
Participants
the
in
strips
pressure
in.put
in
uncertainty
is
The turbulent boundary layer
transition
the
the
avoid
to
coefficient
lift
The
data.
the data
of
the
computations,
I
addition,
A major
of
location
the
at
*'.
However
locations.
point
transition
attack caused by wind-tunnel wall interference.
angle of should
and
Re,
CL,
M_,
the experimental
coordinates,
the airfoil
test should be
for each
input data
The
free-stream
the
coefficient
must be cor-
2___ 4-riP
corr
exp 2
(A Np/Mo L
e
Lhere corr
7 MCor crr
(2)
exp
S~where -•+
L
A
3
2
3M.5
(3)
or exp-
These
formulas were determined
total pressure
is
unaffected
from the condition that the ratio of measured static
tions should be carried out with the imposed lift Drag should be evaluated
The
by the Mach number correction.
in
(i)
terms of
iual
coeff
e
theoretical
far downstream,
C.-
(2)
ir
a ...
surface pressure and surface ihear stress.
532
•
.
- .
.
,
- .
.
.
"
"
•..
,
to
computa-
To
distinguish
ics)
and
when
possible
airfoil
numerical
between accuracy
com•.,ttors
coordinates
lar pressure
near
of
the turbulence model
the
inviscid
the full viscous
trailing edge
theoretical
Srec-ed experimental
surface-pressure
flow
flow.
should
shock Mach number equal to that occurring The
(or shear-layer
compressible external--flow solutions
calculate
as for the
errors due to
2822
using
and M_ should be
that
the
same regu-
taken to give a
the highest Mach number case.
distributions
surface pressures.
RAE
we recommend
The usual Kitta condition of
be used,
in
around
numer-
Results
should
be
compared with
the cor-
for upper and lower surface quantities
should be plotted on the same figure. Mach number
If
corrections
are employed
mental pressure
distributions should
computed
of
should
be
locations
values
a
(angle
included
in
(xt/c).
The
a
of
attack),
tabular
in
the calculations,
be corrected using Eq. total
output
skin-friction
that
and
drag, also
pressure
integration of the skin-friction and surface-pressure A record of successive
adjustments
lated shock location should be reported
to the in
the plotted experi-
1 above.
In addition,
skin friction,
and pressure drag
lists
M,-,
Re,
drags
are
to be
CL,
and
computed
angle of
attack,
Mach
number,
tabular form.
533
-
.-----.
transition from
at.
distributions.
I533
........................
the
..
and re-
PLOT 1 CASE 8621 FILES 70-74
FI
LE
I 0.004
0
e/c
L0
0
TI
0
71
0
0.000___
PLOT 2 CASE 8621 FILES 70-74 (FI LE)
7
6
CASE
Z.5~
i
2.
0
0
00
0
1
C01
0 X/C
534
.......
,
9
j
12
PLOT 3 CASE 8621 FILES 70-74 (FILE)
ooo4 0.004
6
ASE
1 0
I
o 0
C
7
t
-':"
1
9
4 0
','.
0t
i
0
;1
0o0
t
t
I...
I
oj
0
10
o -
0 0
0*
10
10
0
0
0
CI 0
0
x/c
PLOT 4 CASE 8621 FILE 4 (FILE) :
0
"o
,4
S.'
-
-.--
-1-
0
0.5j
X/c 535
-- -.-.
•.
.-
•
-
-
i.
A _.
_.
-
.
,
4
PLOT 5 CASE
B621 FILE
'
~(FILE)
'
II
Cp
'
PLT6CASE 861FILE 6 L
t(
CASE IF1LE) 7,
*
I
0,
c" *
0000
..
Li-e
, 30C^
' - ,9
.CC]
..
I
'"::
6
-A53
(FFE ..
.
.
.
PLOT 7 CASE 8621 FILE 7 (FILE) CA SE 9 S0
ODO
o
•_
0
0
•00 A (')
'
' o c'
-
C,
x
.~
0L
-
V
0
0
0
,
J
,.
~~~
C•,.,. 0 Qý
PLOT 8 CASE 86.91 FILE 8 (FILE) CASE 12
0.
0
:.o,
'.00"
00-1%-0,C -
0 S
[~-'-
,-
0
I
C.
L )l,"i
*F
O
rC
, -
!
,
5-7
S•-•
°°°°' o
0oo
°° "
F.o
5375
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPRESSIBLE Case Data Takers:
F.
98623;
Data Evaluator:
Spaid and L.
Stivers,
R.
Melnik
Jr. (DSMAý 523s Airfoil)
ELCTQuIA1L SUIJAy. rime
"20-O
DKlE&11-1-torl
dp/4. Case Teker
C.,o
8423
O
$523.
Airfoil
slonika
T•,.
"r,
.
go |
. rf, r
ai
l..
-. '
I
or
{Ohers
I
2
2 "
ft.
'~t,hord)
I
Comments
U/Ue
0 < z/c < 0.04
Profiles for Case 1, upper
0<(U/Ue < 1.0
surface at
x/c - 0.3,
0.8,
See instruction
U/Ue
U/Ue
U/Ue
U/Ue
R.
S.
Shevell
0.95.
0.5,
0 < z/c: < 0.04
Profiles for Case 1, lower
O < U/Ile < 1.0
surface at
x/c -
0.75,
1.0..
0.91,
0.3,
0 < z/c < 0.04
Profiles for Case 2,
0 / U/Ue .< 1.0
surface at
x/c.
0.75,
0.95.
0.85,
-
Profiles for Case 2,
0 < U/Ue < 1.0
surface at
x/c -
0.65,
0.91.
0.75,
0 < Z./c < 0.04
Profiles
0 < U/Ue < 1.0
surface at
indicaLed
Douglas Santa Monica Airfoil, although company name has been changed.
that
tne
the
plant
designation is
0.3,
0.5,
0.45,
0.5,
upper
x/c - 0.3,
0.45,
0.9.
DSMA
no longer
in
is that
an
acronym
for
location,
and
538
....................................... ,?-..
1.
lower
for Case 3,
0.8,
0.7,
upper
0.3,
0 < ztc < 0.04
0.65,
review,
tie.-
Ct7
z/'
z/c
a
6
Range/Position
Z/c
*In
60A-
f.te,
Abscissa
Z/C
4
Other
Ordinate
z/C
3
Red r
I
C
Plot
Cf
f
At,-
I
Airfoils.-
V
o CP
T-at Rig Go.itrty
1.
Io• cy
V.
t.L.
R.
:-.............
Plot
Ordinate
Abscissa
Range/Positico-
Comments
6
z/c
U/Ue
0 < z/c < 0.04
Profiles for Case 3, Lower
0 < I)/U,<
surface at
x/c
0.75,
1.0.
""
Cp
7
0 < ,/c
X/c
< C
-1.8
1.0
0.91,
<_ .
Surface-pressure
< 1.2
C
(P
-
P.)/I/
-
P/2PUfo p Case 2.
-p-
0.3,
0.5,
coefficient 2po.U2
for
Special Instructions: I.
This
composed of thrpe cases designated as follows:
flow is
Case
1
2
3
4.
0.60
0.80
0.80
O°
2.60
1.80
2.40
6623 FILES 6 7,8,9.11
PLOT 1 C.. CASE I UPFER
.
*
SURFACE c
-
.
0.5
0.7
0.8
0.95
-'
C..10
i
':
,P':i" 0
0i
.......
.'" .. .
.
<:
a,crc< (Uq
-C __
* °•
.
- +;iiI
/l'
oL
• .
1: -
.
.•j
:
+<:"
t53"9
I PLOT 2 CASE 8623 FILES 14,15,17,18,19 "
CASE• R LOV.E SIRYACE o.04
.,c-o0.3
0.5
0.75
Z/ou[ol
0.91
SI
0.
-0-
-S0o o.
0.5 1
05
/.5
1
0.
0.5
0.5
I 0.45.5
x/ 0-
05
"
.I
PIE 0 8202, 1 1 1 0.5
0.95 095
I"
0.•"04
0
1
0.
I
I
1
0.
1
0.5
1
--
1
.0
0
,
I."
0.5
i
L 6C 1 1 0.50.5
2
I
-
II
0 1I
I
II
01
I
.I
"Si
0
0 .0 0
Lk
I"
+-
o
2&
"- 0
,
'
i
i
•
;540
L
I
1
1i05 i
,
--
I
0
1
05
,
T4
12/C
0.
1
0.5
""
'29.20,32,3),24 U'-- --PLOT 4 CASE 8G"' FI',LS . I .... . CASE22
: LOWER
I
,
j
.
-/c0.3
0.04
0.91
075
SURFACE
0.65
_
0,7
i
0.o
,II
;;4; - .0
0
0. 02 0.2L
04
U
7
1
0
0
.. I
'I
0. PLOT
CAET .5
,./1
,'
0.
.623
T
3;__
C
0.339 4 ;
c,.s, sC,
U/U c-
0)
I
.
c
io
e
541
VA
A:"
-A
"PLOT 6 CA3E 8623 FILES 43,44,46,47,48
:i ~
~
°°
~
c:As. 3
0.04
L ER- .W
0
SURFACE -/c0.3
1.0
0.91
0.75
0.5
"
0
-.
,
01
o0
o0
0,
z/
0
0
00 0
0
i
I
,i*
1
1.
0.
"
0
°
1
c,,
CASý,E 8623 F-ILE C
PLOT
00 oo
00
C-
CASE .-
0
2
Cp,
1.00
10
00
-05
Lilti
542
-OE
POINTED AXISYMMETRIC
BODIES AT ANGLE OF ATTACK (SUPERSONIC) Flow 8670 Case 8671
Evaluator:
D. Peake
(Prepared by D. J.
Cockrell)
lip
SUMMARY
INTRODUCTION Boundary-layer ber of
1.8 and a Reynolds
by Ratnbtrd were
development
(Rainbird,
Included
cone Is
in
the
sketched in
and
number base~d on cone
1968a,
b).
review by
Fig.
flow past a yawed cone at
a free-stream Mach num-
length of 2.5 to 3.4 x 10 7 is
Experimental data are given in Peake
and Tobak
(198G,.
reported
these references and
The flow
field
past a yawed
1.
EXPERIMENTAL METHOD Two sets of (5-it)
intermittent
surface
shear
"1LO7
12-1/2'
to 3.4
Hence,
x 107.
boundary
no measurements lines made it ments
made
showes it
1-m (9-1/2-inch)
of
taken
free-stream
evident of
that
trip
diameter,
res.i.ts
while
Flowz,
tUnivec[lLy
long (L)
50
cone.
semiangle,
but,
(18-
the second
but at
37
-m (54-inch)
ranged from 2.5 x
(x/L < 0.1).
the time of the
tests
The sbape of the separation
the cone3 were intensity
1.
because the free stream was
turbulence had been made.
free-streami-turbulence
In
to the cone apex
to be fully turbulent
for
have been the
selected at whicn
o/ec
second set
separation lines
evide!:ce of ronicity is
Inc.,
P.
0. Box 244,
of Leicester,
.
are on
given in
Moffett
M,,-
2.1
fully turbulent and lieasurein
this
wind-tunnel
L.8
•
For t)-e first
At these normalized the leeward
side of
the references.
Field,
CA
Engineering Department,
94035. England.
543
.
1.5-m
pressure distributions,
based on axial length,
was used,
the flows oer
the N.A.E.
and external flow-field measure-
tra;isition was assumed to occur close layers were
later
condltions,
3-d
4
set,
-m (54-inch)
surface shear stresses,
No boundary-layer
primary and secondary
a
first
in
facility
to b. .ibout U.2%.
Test ,
1.
the
conducted
traverses were obtained with a 0.457-m 37
Reynolds numbers for these tests,
highly turbulent,
1.82
semiangle (Oc),
were made with a 0.2
long cone.
Both were In
and boundary-layer
pressure distributions,
"ments
are described.
blowdown-wind-tunnel.
stresses
inch) diameter,
set,
experiments
.
.
set,
a/ac
incidences
the boay.
At
both these
During a
run
duration
the cones were less
of
than 3%C,
20
to
30 seconds,
changeH
in
the wall
hence zero heat transfer was assuned.
ments were confined to a single axial station at x/L - 0.85 cones. Circumferential pressure distributions were measured gage pressure
transducers closely
holes
45*
spaced
apart
desired angle of sure
185'.
the
Incidence,
distribution
circumferential
at
data
angle
€
measurement
then
were
coupled pneumatically
given
at
(measured
Surface-shear-stress
about
from
directions
The
the
windward
generator)
were
measured
from flow
Magnitude and direction
determined
experiments
in
the
first
probe
was
out
traversed
with the in
cone
to the
ment
of
angle,
the
1968a),
boundary
to a maximum
above
the
by
using
a
from
of
ar
20 mm
surface
was
of
-5'
three-tube
up
mn
from to
As
traces
were also
probe
contact turned
The accuracy
of measure-
(0.001
and
inch)
I
head
this in
was kept
it
a
about
measuring
position
(0.8 inch),
the
The pres-
visualization
initial
0.025
to
intervalb
touching the cone surface.
layers,
extension
cone
pitched
of shear stresses
local mean stream direction by a yav servosysten. height
was
diameter
of
L
yaw
J 0.20. the second set of experiments magnitude was measured by the use of small Pres-
tubes
rection
(see
in
Rainbird,
the external
(Rainbird,
1968b).
1968b)
The
local
Mach
numbers,
flow above t'le cone were all
Overall
stagnation
good resolution racy of
force measurements
pressure
pI in
pitot pressures
measured using
and flow di-4
flow-field
probes
were made with an internal strain-gage
was
was
is
now not known,
excellent.
data which Rainbird obtained number
at
1.8 atmospheres
pressure-based measurements
measurement
measurement
flight
and
The oil-dot technique was also used to provide evidence of flow separation.
balance.
Mach
of
asee Rainbird,
through
surface
probe
In ton
set
model
circumferential
taken with an oil-dot technique.
boundary-layer
aft of the apex of the using unbonded strain-
during the wind tunnel run.
2-1/2°
of
Detailed measure-
to 0.5-mm (0.02-inch)
station.
slowly rolled
temperatures
Ames
(25
Because
psia).
was facilitated,
it
was
undoubtedly
et
al.
(1980)
high.
As
McRae
in
these experiments and those later
Research
Center.
Similar
it
was so high,
and although the accu-
show,
Repeatability
agreement
experimental
is
good
of
•_I
the
between
obtained at the same results
resulting
fromi
tests made at NASA Dryden are shortly to be presented.
Owing Rainbird
to
increasing
(1968b)
direction in
shows
circumferential
there
pressure
to be substantial
gradients
variation
in
the
as
a/0c
surface-shear-stress
the two tests.
..
544
•
.-
.,
.
*
. -
-..•
increases,
.
,
,
•
.
.
"
.
"
-.
REFERFNCES
*angle
"A computational and experimental McRae, D. S., D. J. Peake, and D. F. Fisher (1980). study of high Reynolds number viscous/inviscid interaction abouit a cone f-t high of attack," 13th Fluid and Plasma Dynamics Conference, AIAA-80-1422. "Three-dimensional interacttonij and vortical. Peake, 0. J., and M., Tobak (1980). flows with emphasis on high speeds," RASA TM 81169. Also AGARDograph currently in press.
-Rainbird,
"Turbulent W. J. (1968a). cone,"~ AIMA Jou., 6, 2410. Rainbird, W. J. (1968b). CP.30, p. 19.1.
boundary layer growth and separation on a yawed
"The external, flow field about yawed circular cones," AGARD
It
NoeShock
LIL
K
Figure 1.
Test configuration, Case 8671. 545
Flow past yawed cone.
DISCUSSION Flow 8670
"-4'
S. Kline:
Which of the 10 variables are most important?
,D
0. Peake:
Skin friction and pressures.
.
P.
How did you find the center of the vortex?
Bradshaw:
From the point of minimum pressure.
D. Peake:
You assumed that you had a fully turbulent boundary layer at zero angle
M. Morkovin:
"-
of attack, where in fact it Our evidence
D. Peake: totic
from pressure probes and from the straightness of the asymp-
lines
separation
was not. transition
that all
suggests
were confined
effects
very
close to the nose. on the cone surface;
A secondary shock was induced
G. Paynter:
do you consider this
the same kind of phenomenon as swept shock interactions? ID.Peake:
Yes!
Although it
was not well behaved for the lower Mach number cases.
imbedded shock existed for the
An
case.
M - 4.2
G. Lilley: Are the position and height of the vortices at
M -
4.2
1.4,
similar to
what you get in the incompressible case? D. Peake:
Yes,
dominated by the circumferential
The flow is
very similarl
pressure
field. J. McCroskey:
What is
the uncertainty of
turbulence models for this flow which is D". Peake;
I think so!
static pressure,
It
is
the
Can you discriminate
the data?
among the
so dominated by the pressure field?
same magnitude
± 12-15% for skin friction.
other cases;
as in
± 2% for wall
Experience to date shows sensitivity
of the models to these variables. You had an adiabatic wall in the wind tunnel; how does this compare with
E. Reshotko:
your flight tests? D. Peake:
Some heat
transfer occurs
in flight,
but we don't expect
these effects to
be large.
546
"""~~........"..-.-.-'.-..
-.................. '..° . .-, .-,-,
:-
",
..
.
.
.
."'
."
-
"
2
-
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/COMPRESSIBLE Case #8671;
Data Evaluator:
Data Taker:
D.
J.
Peake
W. Rainbird
PICTORIAL SLW•IY Flow 0M70.
. S- a.l..tares
b
D. Peek.
(D.
J.
Gachkrel1).
"P.lstai Lziklt.71 $teltls i
wole&or of
Veo
City
TorboL..o
e
Sc "
r
"$reoot.)." 0dies .1 MIlor
(t
a. rod
Profiles
dp/dw Case Data. "kor
To.t
IUS
0o
,crf
or C
U
pt
or w
.
71
w-2
Other,
Co., 8071 S..-
1. selubird -
-
-
C1
P..
o.
bi c4 hw1.. pr - o@ d r
-
ol-
Re0
Oter Rates
..
20V..-.Lreeg to
2.4 * 1t tO (at bil
,e.s 1
on ____________ -_~
torb.1-ee
- 0.1."
D'Aa va t
•O 0 of &Ct.ak.
t
-t "-
Ito,
oto, .o.
Plot
Ordinate
1
Cp
Abscissa
Range/Position
< Cp
Cfe
*
0 <
av/0
5
6
at
< 180"
at
0 < @ < 180'
6*
*
0 <
021
0l,
*/
0 <
0.85. x/L
-
0.85.
thickness at
x/L - 0.85.
< 1B0
Displacement thickness at
x/L - 0.85. Boundary-layer thickness
180*
-0.0005 _< 6i1,
x/L
Boundary-layer
-0.0005 < 6* < 0.002 1 7
.167
x/L - 0.85.
Vortex height at
0 < 60.99 < 0 0"5 m 6
x/L - 0.85.
Local skin-friction coefficient
0 < 4 < 180' 1.0 < eo,/oc < 1.4
0.99
L
Surface shear stress direction
0 < Cfe < 0.003 4
O St -n .let %/.. 0.95.
pressure
distribution at
< w . <50'
-30' 3
Circumferential
0.15
0 < ý < 180'
ws
N .... tto,
-
)
Comments
0 < 0 < 180. -0.1
2
.,
021
parameters at
x/L
-
0.85.
< 0.00075 m
8
012,822
0 < 0 < 180' < 012, 022
Boundary-layer thickness
-0.0005
parameters at
x/L - 0.85.
< 0.000075 111
547
-""°"" . -"'................. ...... .....
S.~~~~~~.................................. ,*""-1•
* .
.,.
.
.
.
.. ."
L -,
,
,- ..
.7..
".. ....
. ,'.
.:i
.. • •
*.e•
. '•
"' 'J!°-"
"
" '
-.-
Special 1.
The
flow field
semiangle
sharply
supersonic
Fig.
angle
1 and consists of a incidence
of
of
2
L,
in of
a 2.5
were 1.8 atmo-
1'C, respectively.
these
loss
12-1/2'
22-3/4°
number based on cone length,
in
downstream of The
an
Rt
the stagnation
conditions,
the flow field is
flow evaluation methods it
overall
set
in
pressure and temperature
Under
2.
cone
sketched
the experiment,
spheres and
some
pointed
is
flow at M - 1.8 and a Reynolds
In
X07
to be calculated
Instructions:
accuracy.
not wholly
may be necessary
Assume
that
the
conical.
However,
in
to assume conicality with little
boundary
layer
is
fully
turbulent
the bow shock.
x-coordinate
is
measured
along,
and
the
y-coordinate
,uoulM
to,
the
cone
axis.
Special Nomeaclature local skin-friction coefficient,
Cfe
-
Cp
- local surface-pressure
60.99 -
Tw/0.7 peMe2
coefficient,
boundary-layer thickness,
where
(p. -
p-)/0.
7
pM21
U/Uo - 0.99 h
6
- streamwise
displacement thickness
"crossflow displacement
thickness
el-
'
he h_eV -
-
e 0
" -..
Oil
'h ee 0
Uu-
P
dh
PeeeUe
d
e
Pe Ue
__dh Ueh d
Ue
h 612
1
.pV U pU P
0
(I
e e e
0h •'.21 o r
he
022
U
e dh
V.~rious momentum thickness in streamline coordinates
U P U d e e e PV___ 2 dh e e
"h Editors' _.,O
distance normal
Note:
surface.
Because the data were not received in
for this case were not the 1981 meeting,
to cone
prepared
however,
for the
1981 meeting.
and the data were later
548
% -..
time at Stanford,
standard plots
Computations were accepted
put on the tape.
for
VARIATION IN Cf/Cfo FOR BLOWING/SUCTION WITH MACU N•MBER
Flow 8310 L. C. Squire
Evaluator:
SUMMARY (presented at the 1980 Conference by E. P.
In an earlier letter to Professor test case
S. J.
Kline,
L.
Sutton)
C. Squire had explained why a
"Variation in Cf for blowing/suction with Mach number" was impossible to be
drawn up based on the experimental data presently available.
E.
P.
Sutton presented
L. C. Squire's conclusions to the Conference.
DISCUSSION FLOW 8310 The conclusions of L. C. Squire were regretted but no contradictory evidence was offered to the Conference. [Ed.:
This case will be excluded from the library and the 1981 meeting.]
[N
44
21
Cambridge University,
Trumpington Street,
Cambridge, 549
6.'4
CB2 1PZ,
ENGLAND.
SESSION KII
Chairman:
P.
S. Klebanoff
Technical Recorders: J.
M. Lee Gerrard
ItIi
Flow 0350 Flow 0290 Flow 0470 Flow 0280
PM-
.
550
.
.
.
.
TRANSIENT FLOWS
Evaluator:
L. W. Carr
SUMMARY Transient flows lie beyond the defined scope of the 1980-81 Conference. W. J. McCroskey and
L.
W. Carr of the Army Air Mobility
are planning a meeting in
Toulouse early in
Command,
Moffett
1981 on transient flows.
However, Field,
CA,
They have been
collecting data and sponsoring further experiments as possible trial cases.
The data
are being added to the data library established by the 1980-81 Conference. Mr. Carr reported on the current state of the data in transient flows.
REFERENCES Acharya, M., and W. C. Reynold1s (1975). "Measurements and predictions of a fully developed turbulent channel flow with imposed controlled oscillations," Tech. Rept. TF-8, Thermosciences Div.. Dept. of Mech. Eng., Stanford University. Hussain, A. K. M. F., and W. C. Reynolds (1970). in turbulent shear flow," J. Fluid Mech., 41,
"The mechanics of an organized wave 241.
DISCUSSION The 0151;
Conference
agreed
Hussain and Reynolds,
that
the
unsteady
flow
0150 (Acharye
and Reynolds,
Case
Case 0152) should be kept in the data library, but not be
considered as test cases in the 1981 meeting.
.
...........
551
,2.
SHIP WAKES Flow 0350 V. C. Patel
Evaluator:
SUMMARY 4.
is usually weak,
thin and the cross-flow within it
or leave the surface,
(which may remain buried within the thick boundary layer
of
giving rise to an open or free-vortex separation),
the viscous and inviscid
action between
flow over
the
The
leading to the forma-
characterized by la:•ge and reversing cross-flows,
tion of longitudinal vortices
stcnding
the ch&racteristic geometry of the
a rapid thickening. of the boundary layer over a short distance.
stern leads to stern fluw is
a ship is
middle body of
on the
boundary layer
three-dimensional
the
Although
the
flows as well as the stern waves.
is
stern
and an inter-
therefore
a necessary
An underto
prerequisite
the
The velocity
understanding of the wake since the wake originates in this environment.
field in the wake is obviously three-dimenisiorial mnd is dictated not only by the upstream stern flcz but also by the local influence of propellers and the waves at the The wake of a surface ship is
free surface.
therefore an excellent example of a "orm--
plex" turbulent shear flow. CRITERIA
that quite extensive related
are to be documented experimentally,
complexities
the various
If
it
is
obvious
Naval architecture
and detailed measurements are required.
and
literature was examined to identify experimental data which met the following
criteria: (a) The data should have well-documented upstream conditions, e.g., measurements in the thin three-dimensional boundary layer at some section on the hull. (b) Meesurements should have been made at several streamwise stations over the stern and in the near wake. should be possible to extract the neeisary boundary conditions (c) It required by modern calculation procedures, e.g., hull geometry and pressure distribution, velocity field outside the viscous flow, etc. (d)
Since
models,
the
primary
goal
of
the
Conference
is
to
evaluate
turbulence
some turbulence measurements are essential.
AVAILABLE DATA A quick search through the literature indicates that ship wakes have been extensively
investigated.
architecture,
the
word
This observation "wake"
Iowa Inst. of Hydraulic Res.,
is
used
must,
be qualified
however,
synonymously
with
Univ. of Iowa, Iowa City,
a
Iowa
ve'ocity
since, survey
in naval or
the
52240.
552
.%'.'%
.......-......-.- ....-.-..............
=•
-•".
iL___
.•.•
•.A
......... ""%."
,.....
-...........-. .
"..'.....-.'-.
.
-.-. ....
•.
.
...
•
-"
of
distribution
at
defect
velocity
or
location
streamwise However, criteria,
if to
therefore
data
the wake at a
thousands
literally
of
wake
discussion of
the limitations
(Patel,
prepared
1980)
test case.
single
data
sets.
iouble or reflex models in
and on
data may be
the available
of
re-
borne out by a
is
This
on models
"-rthe years on full-scale ships,
performed
tanks and water tunnels,
towing
are
can qualify as a
sets which
.everal experiments
view of
there
Wake measurements
plane.
we interpret the wake in the more general sense, as implied by the above refer to the viscous, turbulent flow over and downstream of the stern,
are no
there
and
propeller
Pitot traverse across
to a
with towing-tank models usually refer
the
near
wind
in
Some
tunnels.
the Review Report
found in
for the Conference.
RECOMMENDATIONS
reliable is
surprising
not
to find
There
however,
is,
criteria.
under way
at several
in
England,
near
wake,
extend 1974)
Larsson,
on
already
into
the
in
in
progress
the
the
to
flow.
tunnels offers
wind
data which may meet through the
the
experimenrs
Association and
in
boundary-layer
stern
measurements
the stern
layer over
A
vortices.
two
The latter
Sweden.
and the
recent
unpub-
gives a preview of the complex mean velocity
(1980)
the near wake. be monitored
hull
boundary
of
of
it
fdr Schiffbau der Universit~t
completed
thick
be used
this type
Ship Research
British
the Institut
development
by Kux and Wteghardt
the stern and
investigations
the
of
this direction
the
Statens Skeppsprdveningsanstalt
and the
with emphasis
lished report field over
Institute
set
complete in
being made notably
seek to
1976;
(Hoffman,
is
laboratories,
the National Maritime
investigations
The use of double models in a
environment,
that can
no data set
claim to address
methods which
of making
difficulties
three-dimensional
at present,
is,
for acquiring
Progress
Germany,
such a highly
of hope.
a glimmer
suggested
Hamburg in
there
that
near-term prospects
the best
in
of calculation
the performance
test
measurements
and detailed
the associated
the flow and
of
the complexity
view of
In
It
is
recommended
and evaluated
that
the results of the
as they become
available,
since
they may provide suitable test cases. REFERENCES
Hoffman, einem 343. Kux,
L'ncersuchung der 3-dimensionalen, turbulenten Grenzschicht an H. P. (1976). Report Univ. Hamburg, Schiffbau, im Windkanal," Inst. Schiffsdoppelmodell
"Three-dimensional measurements near the stern of a J., and K. Wieghardt (1980). double model of a ship," unpublished report, Inst. Schiffbau, Univ. Hamburg.
An experimental investigaPrrt III. "Boundary layer of ships. Larsson, L. (1974). tion of '.he turbulent boundary layer on a ship model," Statens Skeppspr~veningsanstalt, Report 46.
Patel, V.
C. (1930).
"Ship wakes:
1980-81 AFOSR-HTTM-Stanford Computation and Experiment.
an overview of en:perimental data," Review Report,
Conference
on
"553.-
Comple-<
Turbulent
Flows:
Couiparison
of
LAMINAR-TURBULENT TRANSITION Flow 0290 E.
Evaluator:
Rashotko
SUMMARY
E. E.
Reshotko
and
Reshotko reported
Morkovin
M.
these conclusions
that
earlier
reported
had
no
usable
cases
exist.
tc the Conference.
DISCUSSION Flow 0290 The viable test
Conference
agreed
with
the
conclusion
of
Reehotko
E.
that
were
there
no
cases at the present time.
-J
'4
*Case-Western Reserve Univ.,
University Circle,
Cleveland,
OH
44106.
554
.,.
., _- .,
. , -
_ -
.
. . ._
..
- ....
,
' ...
.
,.1
.
..-.
.
. .-.. . .-.-.
.
-
-.
-
FLOW OVER THE TRAILING EDGE OF BLADES AND AIRFOILS Flow 0470 Case 0471
Evaluator:
P. Drescher*
SUMMARY
SELECTION CRITERIA A survey of the literature indicates that a considerable work
on
the
sharp or blunt
the following criteria were used:
the trailing edge; of
quantities
important
flow
near-wake region; if
(5)
the flow is unsteady,
are
not
whict
(1)
blades
amount
of experimental
and airfoils
has
beenA
could provide the basis for a test
the flow is complex; (2)
it
is
attached to
at
several
streanwise
locations;
(4)
they
ir"lude
the experimental boundary conditions are known and r,
most of the experiments data
edges of
the data contain streamwise distributions and/or cross-profiles
(3)
(6)
trailing
In selecting experiments
the past.
done in case.
flow over
it
sufficiently
,le; and
is accounted for correctly in the measurements.
reported
in
the
detailed,
literature had to be rejected.
and
the
boundary
conditions
are
the
Thus,
Mainly,
the
extensively
unknown. In a second step,
the few remaining candidates were scrutinized
results can be summarized as follows (for details, see Drescher, -
Sharp trailing edge: the experiment of Viawanath et al.
reliability
imposed
for a test
case.
There is
The
1979-80).:
(1979)
a sharp trailing edge of an airfoil fits the requirements
in detail.
on flow over
of accuracy and
no data set
on flow over
compressor or turbine blades with sharp trailing edges that is suitable for a test case. * Blunt trailing edges: the common deficiency of all data sets conside-red is that the measurements in able.
This is
the reverse flow region are not sufficiently reli-
true for isolated bodies as well as for cascades.
FLOW SELECTED The
experiment
trailing edge is The flat plate is a pressure
of
Viswanath
et
al.
(1979)
proposed as a test case.
on
compressible
a
0.0254 m thick and the tunnel height is 0.381 m.
thick and fully developed.
*Brown, Boverl Ltd.,
CH-5401,
Baden,
Data were taken at
Switzerland. 555
*ii
sharp
:iii il i iiiiii!ii~ii!!i ii ! i
I.
The model provides
gradient region upstream of the trailing edge similar to an airfoil.
boundary layer is
iii!a *T.iii !iiiil~
flow over
The model configuration is shown in Fig.
The
161
where
M
model
-
nominal
length
peracure
Re - 36.6 x 106,
u - 0°,
Re - 24.3
a
M
(c)
M - 0.4,
free-stream Ma
x 106,
h number;
a -
stagnation
-
Re
is
-
and
6.250.
based on
'ree-stream
deflection angle of the aftbody flap
PT
pressure,
'positive
x 105 N/mr2 ; and nominal
2.75
-
conditions
and
dl.rec-
total
tem-
- 266.7*K.
Flow-field conventional model
0*
0.7,
(b)
L - 0.9289 m;
tion: clocl-wise);
a
Re
M*
24.3 x 10
0.4,
(a)
measurements
pitot
surface
as
surface-pressure
and
static
well
as
were
probes. on
the
distributions
energy peofiles across
made
using
a
laser-Doppler
Static-pressure
tunnel
top
and
and mean-ealocity,
the boundary
velocimeter
orifices
bottom
were
walls.
provided
The
tutbulent-shear-stresc,
layer approaching the trsiling
8nd
data
also
on the include
and kinetic-
edge and across the
near-wake. Several flow
field,
checks were performed as
see Drescher,
well
as
1979-80,
reveal any significant mei.t
to assess
for the lest
to validate
the uncertainty
and Viawanath et deficiency,
downstream
two-dimensionality
al.,
within
0.25% of PT'
± 8%,
and static
static
locations
Furthermore,
is
a - 0',
where
did not
the balance
is
very
According to the worst-case analyare accurate within ± 4%, turbulenL
on model surface
0.4 x 10-
the total
(for details,
the checks
and
tunnel walls
pressure on wake centerline within 3% of PT"
Ln the probe/measurement y-directlon.
Essentially,
M - 0.4,
pressures
measured data
of the
the momentum balance showed poor agree-
senjitive to the accuracy in the evaluation of 8. sis doi.e by the experimentalists, mean velocities
quantities
the
1979).
except that
station at
in
and symmetry
m in
values of the
the x-
within
The uncertainty
and 0.25 x 10-3 m in
turbulent kinetic energy were Cal-
culated on the assumption that the contribution of the unknown spanvise component, is
equal to
th!
w2 ,
v 2 ).1/2
(u+
ADVICE TO FUTURE DATA TAKERS Thete are trailing-edge
numerous experiments region at
not
adequate
for
are
detailed
flow-field
tions.
varying
reliably
Therefore,
in which a few flow quantities are measured in
flow conditions
testing sophisticated
measurements
future
efforts
at
should
fixed
and model
configurations.
computation flow
concentrate
methods.
conditions on
that
and
task.
What model
They are is
flow and 0
compressor
(b)
a blunt trailing
and
turbine
entire Mach-number
blades
(a)
edge in with
Sufficiently
a sharp trailing edge in supersonic s.tbsonic and supersonic flow;
sharp and
range.
556
blunt
trailing
needred
configura-
talled and reliable data sete are lacking so far for:
* airfoil3 and isolated bodie.s with
edges
in
the
the
de-
Since
the
accurate
specification
of
the
initial
complete
flow
conditions
are
prerequisite
for a credible
compa.ison of ccmputation and experiment,
it
they
be
In
approaching
should
ti'8iling edge.
In
able distance the upstream culty
measured.
upstream
of
the
subsonic
tially
unsteady.
this
refers
the flow
region.
The
to
flow
measurements
must
essential the
a consider-
therefore
Include
flow at the base apparently provides the main diffi-
flow because the wake Therefore,
the
is already affected
from flow over a blunt trailing
in taking good data in
base
The reverse
region.
arises
particular,
the case of a blunt base,
is
a
is
of
instrumentation
edge.
A further difficulty
the vortex street type and thus essenis
required
which permits
instantaneous
measurements.
Editor's
Note:
Important
remarks
appear
the comments
(Flow
in
concerning
measurement
by Simpson
(Flow
in
0430)
reversed-flow and
Eaton
regions
and Johnston
0420).
REFERENCES Drescher, P. (1979-80). "Flow over the traili,.g edge of blades: final report on the evaluation of data," submitted to the Organizing Committee, 1980-81 AFOSR-HTTMStanford Conference (.n Complex Turbulent Flows, Part 1, February 1979; Part 11, .May 1979;
Part
[11,
April 1980.
•
Viswanath. P. R., J. W. Cleary, H. L. Seegmiller, and C. C. Horstman ing-edge flow,; at high Reynolds number," AIAA Paper 79-1503.
(1979).
"Trail-
I OIFFUSER
BELLMOUTH
SPEED CONTROL
fit
-1 2354
(bi
Li
N
-
0
,
R -0.5S2
-
"
9S2.29 __
.
N
ALL 01I|NVIONS,.'
Figure 1.
Schematic of
test section and tAst model.
551
---
'"
55
S~ ~ ~-
-
-.
~
*Aff~at~.
-A
DISCUSSION
Flow 0470 The attendants its
Conference present
acceptance.
evaluated
(see
recommended believes
A number in
the of
particular
use
of
flow was
other the
Case well
reports
uf
558
Viswanath
documented;
two-dlmenqional
0360).
A1-1
0471,
V.
C.
wake Patel
et
there flows
al. was
exist
concerning
(1979).
The
no objection
to
and
be
need
Flows
to
0350
arid
SPECIFIC(ATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Case #0471;
Drjta Evaluator:
Data Taker;
P.
R.
P.
Drescher
Viawanath et al.
flTI&'~lAh. 1U14A*T Vlm 0470.
Data Ktalautori P. ODrecher,
"Vlo
.
var the Traimi& zg, at 9lad.4
Asd Arfo0
l,".
Num4.rof Stationshsoasrd Vm~u4•Lty
Cage
dp/d. or
Test Big
Date Toker
Canf 0471
Cp
U
Practise"-,
-.
utrj
I
4khor
Ct
I
_ubs2L
__rt_
-
aure
_
is. ,
Ordinate
Abscissa
Range/Position 0 < y < 0.015 m S- 04, a -
/()U)ref
ref
a - 0'
0 < y < 0.02 m M -
y
U/Uref
a
0.4,
y
T/(pU
y
0 < y < 0.02 m
),.ef
K/U ef
y
a - 00
U/Uref
-0.02
y
-T/(PU 2 )ref
< y ( 0.02 m
y
K/U ef
a - 6.25'
-0.025 < y < 0.025 w M - 0-4,
9
u - 00
0.7,
M - 0.4,
8
-0.025
a - 6.25*
< y < 0.025 m
M - 0.4,
a - 6.250
559
,
..
I eCasa..
I07 0.
.. d ala7.crtc
".
Com.hent s
.
.
.
4.3,
4 curves at
x/O
43.0, 94.5.
See Instruction I.
4 curves at
x/0o = -2.7,
4.3,
x/e0
-
-2.7,
4.3,
4 curves at
x/
= -2.0,
3.2,
32.5,
See Instruction 2.
- -2.7,
"
43.0, 94.5. 4 curves at 43.0,
94.5.
71.4.
4 curves at 32.9,
0 < y < 0.02 M -
7
00
a - 0'
M - 0.7, 6
-
0 < y < 0.02 m M - 0.7,
5
00
0 _< y < 0.02 m M - 0.4,
4
ic tralltlg *al. to.., flap 0a4L..
Sr-
r
U/Uref
2y
er N.J..
" (0n chard)
7
7
"G1/L.0 ISO Plot
La
)Grtable toIo
uok. pros-
.1. Cloy . 4. Soagailler C.
V o., r
U
rbu|oncao
00
x/0 0
-2.0,
3.2,
71.4.
X/6
-
-2.0
3.2,
4 curves at
x/0
- -2.3,
4.0,
36.2,
See Instruction 3.
8s at 32.•,
,1.4.
79.1.
4 curves at 36.2,
- -2.3,
4.0,
x/8 0
= -2.3,
4.0,
79.1.
4 curves at 36.2,
x/6 0
79.1.
-'
Plot
Ordinate
Abscisaa
P"PT
x/L
0
Range/Position -0.24
< x/L < 0.2
M - 0.4, P/PT
i1
x/L
-0.24
a -
p/PT
x/L
-0.24
Refceence values PT
2.
Reference
"PT
values
"3. Reference y/0
is
0
5,
eo
(optional).
Pressure distribution
on surface
and .wake centerline (optional).
(,U
2
)
5.163
-
14
/2 /rn
t1
6:
ref
(pU 2 )ref
215.8 m/s,
-
104 N/m 2 ,
13.375
0.195 cm.
6o
for Plots
2 2.75 x 105 N/m ,
PT 4.
for Plots 4,
values
on surface
0.147 cm.
00
2 N/m ,
" 2.75 x 105
dnd weke centerline
6.255
a-
(optinnil).
Pressure 6LstributLon
a - 0'
Special Instructions: for Plo s 1, 2, 3: Ur f - 124.2 m/s; Nre2, "ref"
N/,
10
2.75
-
and wake centerline
< x/L < 0.2
'1 - 0.4,
I.
Pressure distribution on surface
0*
< x/L < 0.2
M - 0.7,
12
Comments
8,
9: Uref -
(pU2)ref 24
153.6 m/s,
7.592
x 10
N/M
2
- 0.177 cm.
the vertical coordinate
normal to the model centerline;
it
is
measured
from
the model surface and the wake centerline. The flat
flow
plate
elude
the
6.6% is
to
be
calculated
positioned top
is
shown in
symmetricall,
and bottom
walls
in
Fig.
between the
I and consists
parallel
flow calculation,
not small enough co assume negligible wall
method,
the
"Reynolds
equations and Large Eddy
measured
wall-pressure
walls.
distribution
It
since
interference. can
be
used.
of is
a
two-dimensional essential
the model
to
blockage
inof
For a boundary-layer Computations
Simulation can calculate the wall-pressure
using
distribu-
tions. -9
Commence the computation the
first
measurement
"enough behind "The model can
sufficiently
station
the trailing edge
(i/L
-
far upstream ar.d match
-0.220).
Position
the
the measured data at
downstream
boundary
far
that the streamwse gradients are asymptotically zero.
be assumed adiabatic.
560
..............
.
_
.
_.
"j2
"-I PLOT I CASE 04'(1 FILES 7,11,15,17
941
43.
-2.7
X/00
oo
y (cm) I
4l
0
00
1
0
0I
I
•
.
"
0
S1' 00 0
I
I'
1 /0
y(cm)
T
43.0
4.3
4-,0
-27
:
U/
0
o/. 5
rc,f
•
1-0
0
0
0
.
.0 .
0.0025
(. 0
.
. . . ..
..
' °
i
0
V
-
.
. . . . 0.0025
. . . . . ..
.
.
.
..0 .
. 0.0025 . .
.
. .
.
.
561"'
0
.
.-
0.0025
. ..
. .
.
.
..
.
.
.
..
i
PLOT 3 CASE 0471 FILES 8,12,15,18.1
/0
4.
3.0
10
y0
0
0
0
0
0., 0
C, ,
*0
0
0
00
0
00
0
0
0.01 0
0.01 0
0.0 10
001
~/~ref PLOT 4 CASE 0471 FILES 2-4,28.32.34 -2.0
i/eo
3.2
32.5
I
j
0
*
0
0
0~
\*
71.
(c
CC,
0~
) 0
00
0 00 0 0
0
0 0
0
562
C 0
J
I "PLOT 5 CASE 0471 FILES 25,29,32,35 --
x/8
2.0
32.5
3.2
71.4
00
"0
1
0
1-
v"
10 00 0
-
0.
-]
--
-
'0
000
0
0
1
*10
"0
0.005
0.005 0
0.005 0
0.005 0
PLOT 6 CASE 0471 FILES 25,29,32,35 -..-.-
X/00
--2.0
j
3.2
I 0
32.5
71.4
10 +0
,
y(cm)
10
I"
0
+0
10
00
0
0
S0
o0 000
0
4
+
p
0o
0
00 - I
0
_
0
0
0.01
0
0.01
..
0 01
0
K/'
!
0
0.01
ref
563
'--
7....-.. ..
. ..
i .-_A
PLOT 7 CASE 0471 FILES 43,45,47,48 -2.3 4.
x/6o - -2.30
36.2
0
01
0
2 0
0
o--
0
0-t
0
0 0
~
y (cm)
0
0~
0
1
0.
79.-1
0
0
t
o
.
I
o
0
00
~~00t 0
0
0
0
0
0
*
0
4
00
--2
1
0
1
0
1 0
0
1-TU/U ref
,FILES 4245p,47,4S6
8, CT s471 2;;.5r
0
F4.0
oA
-I -2/80
0
IF36.2
-- l
--
79.1
0 00
,
0
0.I 0
0
i
0
t
0
0
00
I0
"o -0.0
0
0 0o
-0 0 e]
i•
J'''e
0
0 :0 0
*•0
I'
564
.~ S
.
.
................
-:-,::-
0
4'
PLOT 9 CASE 0471 FILES 43,45,474 2 .5
/
0
10
y c> I
0
0
° 0
°~
0
01
I000
'i0.0
1
79.1
0
36.2
.
100 0 0,
o
0.
~
0' 0
-2.3
0o:•
°
°
-4-
0
,0
0
I00
.
0
rr
I
I ¶0
-2.5 •k0
0.005 0.010
0.005 0.01
0.005 0.010
0.005 0.010
PLOT 10 CASE 0471 FILE 2
.9
(2.0
°.00
000-
0
00
0.8g
L
-0.2
0
0.2
"x/L .°.
,
565
-
.
-•.
PLOT
.1 CASE 0471 FILE 19
.
0.7
0
0
"
0
p/m."00'00 S~~P/PT
I
0.6
I]
. -.
0.5 -J' -0.2
0
0.2
x/L
PLOT 12 CASE 0471 FILE 36
0.9
00
-082 .
0 .
.
-
.
-0.2 4-
. . . ..
.
.
.
. .
. .
x/L
0.2 .
.
..
.
0 .
RELAMINARIZING FLOWS Flow 0280 0282
Cases 0281,
K. R. Sreenivasan
Evaluator:
SUMMARY
INTRODUCTION Relaminarization
right pnysics is
classes
rendered the
flow.
relaminarization
flows have
of
flow is
turbulent
its capability for predicing accurately the succession of stages that
a relaminarizing
Although
a process by which an initially
An extreme test of whether a turbulence model incorporates
laminar.
effectively
occur in
is
in
occurs
been documented
a
in
wide
variety
sufficient
of
only
circumstances,
these classes of
detail;
two
flows
form the subject of discussion here. INCOMPRESSIBLE ACCELERATED TURBULENT BOUNDARY LAYER
CASE 0281.
layer developing at constant
A turbulent boundary up to
walls)
wind-tunnel
x0 is subjected
This can be accomplished,
beyond xo.
acceleration
a point
pressure
to a
sustained
for example,
desired shape on the opposite wall of the wind tunnel (Fig. the boundary
layer
tends
asymptotically
to
a
laminar
on one of the
steep,
streamwise
by fixing a liner of Experiments show that In the
past,
nearly
1980).
Selection Criteria (i)
Initial
It
conditions:
boundary layer be self-preserving in
1).
state.
thirty flows of this type have been studied (see Sreenivasan, a.
(say,
a calculation
method,
desirable that t'e initial
in constant pressure;
not directly measured,
tively high degree of confidence. few thousands)
is
are also desirable
state of the tuebulent
those initial functions needed
can then be prescribed with a rela-
High initial Reynolds numbers (Re of the order of a because this eliminates the possibility of
fying relaminarization in this class of flows with low-Reynolds-number (ii)
effects.
The flow must then be subjected to dustained slep
Flow conditions:
identl-
accel-
eration so that a succession of states from the fully turbulent to the truly laminar occurs. (iii)
At least all mean flow parameters (including the skin fric-
Measurements:
tion) and profiles af Reynolds stresses (both normal and shear) should he measured at close intervals during acceleration,
Dept.
Engineering and Appl.
Science,
especially
in the region of maximum Cf. where a
Yale University,
New Haven,
CT
06520.
567
.'
S "-. '-'••'.i -••- • •--••-./ ii-.- <- -••'.•.•
i'
.
i
'• .". •.''"
°"
.i-'i i . . i
.
.-. • • .. .
i.
'
. .
.
Generally,
!ot of detailed changes occur.
more care than is usual must be taken near
the wall since the linear part of the velocity profile diminishes in extent. (iv)
consistency:
Internal
Momentum balance
and other
appropriate
as
checks
must be applied to ensure internal consistency of measurements. b.
Flow Selected Unfortunately,
none of the available flows qualified as an ideal test case,
but
In these flows,
about half a dozen of them can serve as moderately good test cases.
although there is a general consistency and reproducibility of all essential features, different levels
of confidence
parameters,
can be placed on different measured
and a
good substi*ute to having an ideal test case would be to compute all these moderately good flows with the purpose of predicting in each flow at least the most reliable of the measured parameters.
Since this requires too many computations,
choose one set of data (Flow A from Simpson and Wallace,
1975)
sent a reasonable compromise among these moderately good flows. uation can be found in Sreenivasan (1980). A few words of caution
however:
for the computors,
we are forced to
that appears to rep-.eDetails of the eval-
the boundary layer in
this
flow was developing under mild adverse pressure gradient upGtream of where the acceleso that its initial state is somewhat (but not terribly) different from'
ration set in,
that of the standard constant-pressure boundary layer at the same Reynolds number. SUBCRITICAL PIPE OR DUCT FLOWS
CASE 0282. The
experimental
situation involves a gradual
enlargement
of a pipe or channel
The Reynolds number goes down from, (Fig. 2). R1 upstream of the divergence to R2 downstream. If R > Rcr and R2 < Rcr
Sfr,,,. one diameter or width to another
say,
where Rcr is
an appropriate
critical
Reynolds
an approaching
number,
turbulent
flow
will revert to the laminar state. a.
Selection Cciteria
reasons
For similar
as
cited in
it
Case 0281,
is
desirable
that
the
Narasimha and Sreenivasan
flow upstream of expansion be fully developed.
turbulent
(1979)
have
L
shown that Lhe beat estimate of Rcr (based on average section velocity and pipe radius Thus, the initial Reynolds numbers must be substantially or channel width) il 1500. greater than 150C; the larger the difference is
(Rcr
-
R2 )1 the faster (in
terms of x/D)
the laminar state effectively attained. Th.
angle
of
divergence
in
the
expanding
small to ensure that no flow separation occurs.
section
should
be kept
sufficiently
Other comments made on measurements
in Case 0281 hold here too.
568
..............................
'-. "-..--." :. .....: ..-.. •-.-• .. :"::•:::•............................................................. •:ii:-•-::::-•..:
Flow Selected
b.
*
flows
Relaminarizing Sibulkin
(1962) not
do
tions
this
of
class
any
basic
difference
In terms of both thoroughness
flows.
an examination of the instrumentation)
relaminarizing
between
and accuracy
Laufer
and
(1962)
These investiga-
in a channel.
in pipes and by Badri Narayanan (1968) reveal
by
reported
been
haie
and
channel
pipe
(as judged by scatter ýn data and
Laufer's flow is chosen hern as the best avail-
able test case.
"ACCURACY OF Since
MEASUREMENTS the measurements
streamwise velocity,
of
interest
here
concern
only
nean paraweters
Vie great-
the accuracy of measurements must be generally good.
est uncertainty rests with skin-friction measurements (where made);
and rms
note that In Ca3e
0282, or in any comnarable flow, no reliable skin-friction measurements are available. Typical
accuracy
esttmates
claimed
by Simpson and Wallace
(or
estimated
from other
given information) are:
i*I
± 1/2%, 1
Mean velocity
U
Streamwise rma fluctuation
(u-)1/2 f
Skin-friction coefficient
-
-
L..
± 1%
± 20%
REFERENCES "An experimental study of reverse transition in twoBadri Narayanan, M. A. (1968). dimensional channel flow," J. Fluid Mech., 31, 609. "Decay of non-isotropic turbulent field," in Miszellaneen de angeLaufer, J. (1962). wandte Mechanik, Festschrift Walter Tollmien, Akademic-Verlag, Berlin. "Relaminarization
and K. R. Sreenivasan (1979). Narasimha, R., Advances in Applied Mechanics. 19, 221.
of
flows,"
fluid
"Some observations on skin-friction and velocity Patel, V. C., and M. R. Head (1969). profiles in fully developed pipQ and channel flow," J. Fluid Mech., 38, 181. M. (1962).
Phys.
flow,"
to laminar
"Transition from turbulent
Fluids,
*
Sibulkin, 280.
*
"Laminarescent turbulent boundary Simpson, R. L., and D. B. Wallace (1975). experiments on sink flows," Project SQUID Report SMU-l-PU. "A guide ti., the data in relaminarizing flows," Sreenivasan, K. R. (1980). pared for the Stanford 1980/1981 Conference.
5,
layers: %
Report pre-
569
'.-
*"
....
• .-..
.-
--..
.
.
"'.
.
..
.
.-
.
-
.
..
.
.
.
.
U
Oncoming conntant-pressure turbulent boundary layer
Relarninarizing boundary layer
/
,.
" " .
I
",
Ii
/ /
Wind-tunnel
Figure
/'
.'
Lner
test section
1. Scnematic of experimental apparatus for producing compressible turbulent boundary layer-.
relaminarizarion
of
in-
*-
Small divergence angle
-
Flow
"Fully developed" turbulent pipe or channel flow SR (= 1500) 1 cr (R -Ua/v)
Figure
2.
R < R 2 cr ("Subcriticai" flow)
Schematic of experimental apparatus cal pipe or charnel flow.
for producinig reluminarizing
subc,:iti-4
570
-
,
"
.
-.
,
. ,
"
DISCUSSION
Flow 0280 Conijensus was reached by the Conference rnamely debired; lish
Simpson and however,
Wallace
(1975)
that of the twv test cases recommended,
and Laufer
(1962)
they are the best we have.
"limits" for turbulent hehavior and are
were not documented
as fully as
they are sufficient to estab-
Moreover,
thus important checks.
Hence,
the Con-
ference recommended that the two different classes of flow involving relaminarlzing be usEd as test cases.
Certain
written
layers betueen
Dr.
P.
discussion N.
Inman
on
the. data
(Imperial
evaluation
College,
for
London)
relaminarizing
and Dr.
K. R.
boundary
Sr enivasan
'-egarding future experiments appears important to place on record: P.
N. Irman:
I agree
that
the
"pre-laminarescent"
state should be represented,
and
the existing data sets constitute sufficient information to test ,he performance of turbulence models. The ability to predict the approach to relarninarization tt an essential part of a relaminarization model, so that it is desirable that test cases should start in the fully turbulent regime. Although many n( the existing data have shortcomings, in terms both of quantities measured and of flow quality (especially
iments
two-dimensional ity),
which may be difficult
the
to
report of Dr.
perform.
At
Sreenivasan sugg;ests
least
Ln
low-speed
new exn~er-
flow.
••
without.'
body forces, relaminarization cannot be separated from low Reynolds number effects, since RE always falls well below thn upper limit of low Reynolds number effects (say, Re - 5000) before relamina ization occurs; in relaminarization induced by pressure grad'ients, Re usually fallb to 300-400. The approach to
%
relaminarization from high initial R3 (> 2500, say) is particularly difficult to reproduce in a conventional winu tunnel. To pr( ce R, - 2500 require3 an initial length of order 1 m at Ue - 15 m/s. and a wedge K - ",/Ue(dUe/dX) 3 x 10Also in a "uedge flow" values of angle, say, of 20', implies a tunnel hzight of only 0.12 m and an effective wedge length of only 0.3 m. This length is unlikely to be long enotigh -o give a reasonable range of x/,initial. Dr. Sreenivasan's requirement that the boundary-layer thickness should be not more than 1Z of the tunnel height also causes problems, for then the wedge angle must 'e greater than 55'. Increasing the wedge angle (oz more generdlly shortening the region of pressure drop) allows higher saeeds and higher initial R0, but must be traded against the length of the relaminarization region and the possibility of curvature effects in the outer part of the boundary layer. Also, cross-flows In the tunnel side walls become increasingly violent leading to departures from two-dimensionality of the test bounday layer on the tunnel floor. Th.. constrairts discussed above probably account for the lack of expetiments with initial Ra > 2500. The existing data explore the readily attainabl'_
(Ed.:
Reworded for clarity, hopefully, without change of emphasis.] 971
.
-
--
*
.
. *. -. . . .
.
combinati'.ns
*. .
and
.
".
.
*.
.
the envelope of
*
*
test conditionr
..
-
.
•
.
is
nerhaps
.
unlikely
.
to be
.
.
exten-
•
I
-
ded much in the near future. It would be unwise to argue that because the more extreme conditions cannot be easily obtained in wind tunnels, they will never occur in practice, but future experimenters should be encouraged on better exploration of the easily attainable range of relaminarizing flows than on attempts to produce flows with high Re and high K. K.
R.
Sxeenivasan.
Firstly,
I
agree
that
computing
the
fully
turbulent
"pre-
laminarescent" region provides a challenge to computors, but I want to emphasize that the ability to predict the "pre-laminarescnt" flow is not a necessary prerequisite for a successful prediction of the later stages of relaminarization. In the latter case, it is enough to be able to, say, switch off the production of turbulent energy at the appropriate ooint and merely recognize that further downstream turbulent stresses play no significant role in determining the mean flow dynamics. Unless a model grossly violates the physics (see Narasimha and Sreenivasan (1973), J. Fluid Mech., 61, 417), it is unlikely that the outcome exhibiLs strong sensitivity t- the details of the model. This simplicity (which is nevertheless complicatei enough to be sufficiently challenging) is due to the fact that relaminarization is an asymptotic study asymptotic limits in general.
case.
That
is,
of
course,
-
"< 1
',
why we
Secondly, it is not correct to say that relaminarization in accelerated turbulent boundary layers cannot be seiparated from low Reynolds nunber effects. It is not trut that R0 it. always about 300-400 whenever relaminarization occurs.
1
..
There ire experiments that show the contrary (Patel and Head (1968), J. Fluid Me:h,., 34, 371; Blackwelder and Kovasznay (1912), J. Fluid Mech., 53, 61). I believe. this will also be the outcome in future experiments with higher initial R6 . We both agree these experiments will be difficult to perform. I believe we need to resort to experiments in a large enough wind-tunnel, capable of producing without acceleration-pzodicing devices, such as a liner, a constant-pressure boundary layer with Re iu0,000. Hence when a liner is added, we may have a chance to obtain a ralaminarizing boundary layer with an initial Re of the order of 3000-4000. Lastly, 1 'inbelieve smiller values of 6/h, than are usual, are essential to due to possible normal pressure-gradient effects eliminate momentum imbal'nce, induced by flow curvature but I do not wish to stick to 6/h = 10-2 as a steadfast rule. This rule calls for a large wind-tunnel heighc and therefore a large wind tunnel. Your calculationE are rseful but may be misleading in the context you use them. Large R0 and moderatŽi wedge angles are not incowpatible, if we do not insist on large K. I dc not care to stipulate the attainment of large K and high R6 ; I believe large X is neither necessary nor sufficient for relaminarization. Incidentally, we can always produce targe values of K by resorting to nonlinear wedges. Locally large wedge angles do not produce important cross-flow e'fects is long as 6/h is small enough (see Badri Narayaran and Ramjee (1969), J. Fluid Mech., 35, 225-241).
I
572
~7.-4i
FOR COMPUTATTON
SPECIFICATIONS
ENTRY CASE/INCOMPRESSIBLE Case #0281;
)ata Evaluator:
Data Takers:.
R. L.
K.
R. Sreenivasan
Simpson and D. B. Wallace
PICT[•r AL $L10wY Flow 0250
K. 1. Ir.
Date Nvoloalorl
a
velocity
"Ia4 a.I|.riat.| Plo.".
ftn.
0 f e r 0r N ""1I
.
Turhbolnco Profiles
dphd. Pv Coe* Date Taker
C..
Test Ri Goofttry
r
"
N .. ...rd V.401.
J
I
-
or W
0101 ais
Otth.g Is
-
I.
C'
i
1
2342
Other Not.. Io..n
(based O. Wallatce
Plot
,...,4.1st
Ordinate
Abscissa
Range/Position
x
2.235 < x < 4.846 m
Re
x
2.235 < x < 4.8L6 m
Ue =Ue(x)
2.235 < x < 4.846 m
2
3
C C
x
4
YUe/V
U/Ue
"e
YU/
5
-12
YUe/V
(u 2 )
aft
ref
x
-
/V
-
1
2.718,
Ue
at
x a 2.2
3
5 m.
2.992,
3.486, 3.785 m.
0 < U/Ue < 1
x - 4.239, 4.604, 4.693,
20,000
OYU
r..
Comments
0 < U/Ue< 1 < YUe/V < 20,000
U/Ue
1yer a.".Pogip. lar
ad:.8r m ado: o re • .•.
4.846
in.
/2/ /U
e
0 ( (u)
/Ue<
x
0.1
-
2.718,
3.486,
4.239, 4.693 a.
0 < yU/Iv < 20,000 Special Instructions; possible, provide tabulated output for R,
H, Cf at stations of measurements.
1.
If
2.
The geometry of the test channel is thown in Fig.
3.
Range:
The acceleration
effects do not begin uittil after
thus be chosen as the initial station, continue to 4.
Input:
3.
xo.
x
-
2.235 m, which will
Comptutations should begin at x
and
x a 4.846 m.
All measured conditions at x.,
and the preocribed variation of the free-
stream velocity U.owith x are given in Table 1.
573
....................................................
C-4
4
-4
-4
-
%64
0
'
'0
'0
0
-
0.
-
h
'0
ri /
1
.4
(NN
...414
$4
"1.4 .4'(~l
cr
.40 0
N
IT. -r%'0 0 it)
ýo
'00
1
fn~ en0
(U
(n C
0.
*
0
403 0% 4-4to
C
-
x
"II 0
14
.4
0
0) 43
N4
0)
Go
r-
0%
C"
L
00 %
0
04
00
V
O
C
40 -4 0%C
I
mr-
W
0
-40 8 U
0
0
4
ý
4
4*
-
0
ý
4
C
1
-
-0
40
0-.4
b 43
.
: N,
C-4
C -4
4f4
D
C> 0
w
"
r
V
-
M.)t
4
-T u0 0n 0 43
-
U
43-~
-
-4ý
0
'0
'0
U
U4 .)0
0
%
4
.
%
~4.
'0
'0
'.
U,
#
'0
C4 -
P-~
N .
m
~
040
M
I-
c
n
~L
0
0-4574
4
-4 r x3
2.438 m (96'*)-
0.31
)_____
__________________4.877
Figure 3.
m(l92*)
___
____
Test channel geometry fcr Flow A of Simpson and Wallace (1975), Case 0281..
575
PLOT 1 CASE 0281 TABLES 1,2 0.010
z0
o:: 3
2
"'"0.005tPLOT
2
CAS
028
TALS,
Z.0
--
L=.-
5
4
3
2
PLOT 2 CASE 0281 TABLES 1,2 0
0
-<1-.:o_..2.0
1.0
Ht0
x
kin)
o
0
o
o
I:
-
3
2
5
4
1%,J
.__.;2-:4576
,,-"
-
...
_
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
PLOT 3 CASE 0281 TABLES 1,2 0.005
0 o.040
0
%0
0
II 01
0i
"I
0.003 5
4
;g3
x
(M)
PLOT 4 CASE 0281 TABLE 2
4.8 20000
1
2.18
.992
3.48.78
0 0. m
10000
.' 0
o 0-o
0
,. 0
0
I
r- ¢ •
0
I
1
f5
0
I I
0
o1- ,
1 0
o
--
,.-cc•>o
10
4
1
oc
0
577
...... ,..,......................
...........-. ,
..- , -..-.-.-..-..-.......-
..- ....
"..... ....
.
..
.
,
•
oor
"T •-""~
PLOT 5 CASE 0281 TABLE 2
K
20000
29
-.
I
54.604CAE0i -~
PLO
or-
/U / V
T
-
0
I
010
I 0 4
o
+
I
0
0 I 4
0.0
o00o
+
10
0•--
I
o*
-i
0
1
0
0
0
4.846
0~0
I
I
0 0
AL -
4.693
0
0
e
PLOT 6 CASE 0281 TABLE 2 I
I
I
20000 I0
00
4.69
3
o -
x
I
00I 0I
0.
3
I
. 0
0
oi0 0
~
.
'
1
0 0
44
0
o
1
"
"'
I
0 U
0
0
0
0
01
0
01
1
".(1r
:•
Si00
o
I
o
'
_L
'
-'
c
.
07
/12
'
I
-57-8
... .... .. . ... .. . .... ... .. . .. .. . .. . . . . .. .
'...
SPECIFICATIONS FOR COMPUTATION ENTRY CASE/INCOMPRESSIBLE Cav~e 00282; Data Takers:
Data Evaluator:
K.. R. Sreenivasan
J. Laufer (V. C. Patel and M. R. Head) PICTONIAL SlhWaJy
YIDv0260. gate R~L.altori K. A. 169"Aiei,...
'E.Iue...rItisa
T
Tweeox C .T oo -%l i t it Vat.
Taerp
ilo
ofoC
GuawtrLy
C
w
-a,
-8
Viwo..
s V
0
. "Ie
ther
V
~
C
ti
S----------------71) (b".4o
J.
gate
ci
W.
a~d
t
Ordinate
Abscissa
y/a2
U/U 2
*1
patra. of 41. le) ar&*.
(1969).
Vd.41c
(TI total 4
Plot
Rto. "
ot.
On cae- laltial evam weiftit "ato 4tI9eaa teket Ira. total eu-h q*ed
Range/Position 0 < y/a2
~0
* Y/i
Comments
~.1x/a
2 -
< UN,.< 2
U2
0<>~2(Ix/ U (u2j
/U2
-
2
20, 60, 80, 100, 120
1.06 rn/sec,
a2
.1m
60, 80, 100.6,
-20,
0-
Special In~structionis: 1.
Since
no
conditions
upstream of
divergence
velocity data are ý-akerl from Patel and Head -1725;
are given by
Laufer,
(1969) for appropriate
see Table 7.
2.
The specifics of the Laufer expe~rimentAl set-up are givý3n in :..4.
3.
Start calculation at
x/a~
-34.4
and continue to
579
x/a2
-120.
initial mean R1
Ua,/v U
TABLE 2 Initial Mean Velocity Data, x/a Reference: y/
2
- -34.4
Patel and Head (1969)
1U/U1
0 0.05 0.10 0.15 0.2 0.3 0.4 0.5
0 0.514 0.729 0.905 1.020 1.115 1.189 1.230 1.257 1.297 1.310 1.338 1.351
0.6 0.7 0.8 0.9 1.0
-3 .
x/i 2
"
41,
-34.4
-
[
U.
6.62 m/sec
R2
, 1725
(Uiai)/v
Figure 4.
-
a2 -1
- 0.4 cm R,
."
Parameters of the Laufer (1962)
X.
1.06 w/Mec cm (U 2 a 2 )/v
experiment,
580
-..
.
- -'---
-
690
Case 0282.
PLOT 1 CASE 0282 TABLE 4 1.0 0
o
0j Y a2 y/~
4
0
120
0
oo
0
o
0
0
0
0 0
0
-
"
0
0.5
0-
4
0
0
o0
0
0
0
IB 10 0
0
-° 0
0
20
20
0
0
.
°
°I
i-
0'
0
0
0
-
2
U/uz PLOT 2 CASE 0282 TABLE 4
1
0
.0
200
0
I.. 0
60
100
80
0
"0
.0
Q.p
0 --
0
0.0
o'.
oL-
-
I
0
0
-
_
o
-
0
0
0 .
,-
0
-
0I 0
0.1
0.1
0
0
., *".:'
.
0..
°
±°'
581
0.1 .
0 .
0.1 - -.
SESSION XlIII
Chai*'ian:
J.
B.
,,j
Jones
.1 Technical
Recorders :
R. P.Westphal Moi"
.
•"•
1
Working Group on
L,..°Hot-Wire
Anemometry at Low Mach Numbers (Chairman: B. G. News an
2.
Working Group on Use ,,f Hot-Wire Anemometers (Chairman:
3.
E.
Compressible Flows
Re2hotko)
I Free-Shear Layeru
(Chairman:
4.
in
Working Croup on Hot-Wre
F.
mb
Champagne)a
Working Group on
J
Turbulsnce Maragement and Control ofCLarge-ieddy 3
(Chairman:
WrnCo
,-,
i"
•
REPORTS FROM AD-HOC CO",V=ITTEES
•.--•
H.
Structure
Nagkb)
CLOSING DISCUSSION d-Hoc Committee ron Reports and Sessions I Through X.1
..
:"REPORT
OF EVALUATION
(Chairman:
H.W.
COMMITTEE
Emmons)
%..."
58"
. -
--
---
,
..
-. . "-
_ -. -'.-
.- i ' ' " -
-
". "
-."
..
. .
I AD-HOC COM41TTEE NO.
*1
1
Report of the Working Group on Hot-Wire Anemometry at Low Mach Numbers Chairman: Recorder: Members:
P. I.
B. G. Newman R. Westphal
Bradshaw P. Castro
A. F.
E. J.
7
F. Durst
V. A. Sandborn
F. J.
Gessner B. Jones
H. R.
C. Seetharam L. Simpson
R.
J.
B.
van den Berg
Moffat
I
Perry Pierce
We were asked to answer four questions. a)
What
is
the
first-order
uncertainty
of
hot-wive
anemometry
considering the difficulties of drift? What steps are useful in controlling and measuring the effect of drift? After above),
due
attention
the compensation
quate time for averaging ties) the
the drift
group,
material
in
platinum-iridium b)
been
quoted
to be
paid
to
for mean
removal
values
important.
as
low as
the
is
dust and
(typically
1 .im and
zhe provision of
ade-
100 s for the turbulence qi'anti-
6U/U
1%/month
Platinum-coated
uncertainties
of
temperature
velocity
Wollaston wire soldered Do
the
(typically 10 9 for U; it
calibration
however,
appears
has
for changes of ambient
is
perhaps 2%/day.
and as high
tungsten
welded
Members of
as
3%/hour.
to
the
prongs
Wire and
to the prongs are preferred.
in
(a)
vitiate
meaningful
measurements
of turbulence dissipation? Three ways of measuring dissipation E were considered: i)
Assume local isotropy and Taylor's hypothesis to measure
*ý-up
15V 1j
5M 15v '.~-
(Variants of the method measure more individual components of du
1
but
accuracies
the
Kolmogoroff
layer
claimed
Klebanoff length.
+
.1
are usually siwilar). length
scale
accuricies
Ither members
2
""
The wire
(v 3I)I//
± 10%,
who uses wires of
au
ij
should
Sandborn
which was
0,
+
.1
similar
in to
be shorter a
l-m
the
than
boundary
accuracy
,arious lengths and extrapolates
of
co small
of the group were leas sanguine and thought
that
accuracies of ± 25 to ± 50% were typical. ii)
If tiai
the
microscale
range
of
Reynolds
number
the spectrum may
be
exceeds
expected
100,
a
(Bradshaw).
universal For that
inerpart
583
S. .
-
-.
J
71 ur 0(k)
Kc2/
-
3
3
k-5/
, where k is
the wave number and K
0.5.
therefore be inferred from the frequency w spectrum assuming
C can
k
u /U.
Accuracies of ± 20% were suggested although this way be improved to perhaps ± 10% by ch.. jing K so that the turbulence-energy equation, when Integrated across the flow, is
balanced.
The unknown turbulence diffusion terms
are eliminated by this
integra-
tiolk.
Simpson has used the k
iii)
portion of the spectrum
to obtain C near the
wall, but the accuracy is sowewhat less. It
was concluded
that
c can usefully be measured.
that Nth-order uncertainty shoull be checked scale
such as fully
developed
pipe
However.
it
was
by measuring a standard
flow or a thick
boundary layer
recommended
flow of similar in
zero presbure
gradient. c)
What
is
the
Nth-order
uncectainty
quantities assuning good practice. The following diffidence.
figures
for uncertainty
(Perry).
For a
Can it
in known
longitudinal
linearized response equations may be used.
various
fluctuation
be improved?
estimates are presented with conbiderable
They are based on measurements
probe experiments
Lor
flows and also on oscillating
turbulence
u•Z/U
- 10% or less, U < 2%; uZ normal wire
Likely errors are:
k 5 to ± 8%; crossed wire ± 15%; vw between ± 5% and ± L5%; and v7, -w± Good practice
15%.
for slanting wires involves careful measurement of the wire angle,
and yawing the wire in a smooth flow to obtain the response to yaw. R.
Moffat
had misgivings
percentage of vl,
about
quoting
signal was recommended. the
wire
uncertainties,
relation
rect dgtal
Then only the non-linearities to
the
instantaneous
velocity
Castro referred to the paper by Tutu and Chevray (J. F'or backflow
in
particular
as
a
because this quantity tends to zero rapidly near a wall.
or a hgher turbulence of about 2 of
v2
processg o. the
ot-wire
associated with pitch and yaw vector
need
Fluid A.fech.,
71,
be accounted 785,
for.
1975).
turbulence greater than 35 to 40% sot - rectification of the signal due to is encountered. The use of either a flying hot wire (Coles, Perry) or a
"pulsed wire
(Bradbury, d)
Castro) is then recommended.
Will the hot wire be replaced by the laser?
Everywhere?
In
some applications? We had a lively discussion on this question. 50 years of turbulence measurement,
Hot wire6 have been used for about
lasers for less than 10 years.
There is
therefore
[Ed.. The word error has been changed to uncertainty in editing to make usage con-sistent with that of R. J. Moffat's Vaper in this volume.] 584
""
.
.
,
enthusiasm for the latter technique without
the thorough testing which the former has
received. Fortunately rienced users, them,
and,
three members of our group (Durst, and
in
indeed
general,
developers,
turbulence of very low intensity, flow,
it
of
were surprised
Sandborn,
laser anemometry.
and Simpson)
were expe-
Other members
quizzed
at their claims for the new instrument.
say 1%,
From
to very high intensity with even mean back-
wei; thought that mean velocity could be measured to an accuracy of 0.2%.
A
two-laser system could measure uv to accuracy similar to the very best which could be achieved
with
a hot wire.
Measurements
possib]e with special signal-processing
of
c and also
techniques.
two-point
correlations
were
The non-intrusive nature of the
instrument was recognized as impor.ant in many applications. In
usin',
reflecting seams
to
laser anemometry
particles very take a
graduate
soce difficulties
close to a wall. student
start making useful mee-urements. tering,
may
Instrument is
be
phybically
at
may be experienced
Air flow usually has
to be
paietty of
seeded.
least one year to master the technique
Traversing gears,
difficult
from a
to
arrange
for
and
It to
particularly with forward scatlarge
flows.
The
codt rt
the
typically 2 to 4 times that of comparable hot-wire equipment.
We cuncluded that those who have hot-wire equipment are likely to continue to use it
for many years.
find it
However,
those purchasing new equ.pment to measui'e turbulence may
denirable to invest in a laser anemometer.
J 585
A
.
II AD-HIOC COM•MITTEE NO.
2
Report of the Working Croup on Use of Hot-Wire Anemometers
in
Compressible Flows
Chairman: E. Aeshotko Tcchnical Recorder: S. Pronchick
"Members:
A. A. C.
Demetriades Favre lorstman
M. 'Mrkovin A. Roshko
The committee discussed the two questions: a)
What is the zeroth-order and t hot-wire fluctuation measurements transonic and superAonic flow?
b)
output (pu)'
total
temperature
Rather,
IL
obtaining his hot-wire data.
the assumption that the sensitivity
fluctuations
was
small
relative
to
its
of the
sensitivity
to
Horstman's method of calibration did not address this que6-
Horetman
total
his
procedure used in
questioned whether
had been ver.__ed.
tion. that
the calibration
specifically
to
of
Can they be improved?
Hocstman described Demetriades
Nth-order uncertainqy for various 4uantitP.;
made
measurements
temperature-fluctuation
at
two
different
amplitudes
were
overheats
negligible.
and
concluded
Accordingly,
it
was agreed that the data are acceptable on this score. Favre raised the question of the bandpass width used in was 100 KHz.
It
was felt
that this was
probablv
components
of
sufficient
to retain
considered
to be acceptable as a test case.
Morkovin
the
and
must be verified validity
enery
near~y all
discussing modeling,
with LDV,
pressible
flows,
tha
future.
requirements it
remain an
that
that
but
it
The harstman
calibrations
and Morkovin
in
was
probably
data are thus
compressible
further pointed
flow
out that the
flows with strong shear gradients may break down due
for
future
wnq initially
and would
be
data
which are
to
be
considered
agreed that hot-wire measurements
important
not
Demetriades
Pome discussion of suggested
energy.
hot-wire
which
the underlying analysis.
anemometer applications,
born
turbulent
that
obtaining the data,
to retain the high frequency
tt. dissipation,
using the mode equations,
junction
near
the
noted
of the mode equations in
for use in
related
of
Demetriades
to assumptions made in In
spectrum
too low
method
rendered
then
for
obtaining
7
standards
will,
in
con-
data
in
com-
turbulence
completely obsclete
propoied
by the use
for
suitable
of LDV
compressible
in
hot-wire
which are appended. uncertainty estimates was also conducted.
uncertainty estimates may
be obtained
Horetman and Sand-
by comparing
suitably non-
For a detailed discussion of the mode equations for hot-wire calibrations sible flow, see Morkovin, AGARDograph No. 24 (1956).
in
compres-
586
.
.•
,-..
.
.
.
.
.
.
.
.
.
.-.
....
L
dimensionalized compressible flow.
fluctuating
turbulent
This is
velocity and Reynolds shear-stress
flat-plate
boundary
layer
to
results
measurements made in a obtained
in
low-speed
in line with the "Morkovin hypothesis." Appendix
PROPOSED STANDARDS FOR COMPRESSIBLE HOT-WIRE ANEMOMETRY APPLIC.!TIONS by A. Demetriades I.
Transonic/supersonic/hypcruonic i.e.,
flow facilities should be turbulence-categorlzed,
their stream-turbulence content should be measured and reported:
Minimum: T t
as functions of Po,
To0
i
""
p '.
Desir-bi.e Additions: v t, V. Spectra
as functions
Correlations
of PC,
To, XI
Higher Moments 2.
reglect
The
of
pressure
fluctuations
in
redu-irig
shear-flow
turbulence
data
should be justified. 3.
Free-stream therefore,
turbulence is it
distorted in
should be measured
flowing through shocks,
in the
immediate
vicinity
expansions, (e.g.,
etc.;
just beyond
y - 6) of the measured flow. 4.
Since
large
T
,
p',
p'
can
be
triggered
linearities may be important--especially senqitivity coefficients, 5.
Use
of
constant-temperature
adequate response,
at
high speeds,
non-
precise accounting of the frequency response of the
entire measuring system at all tines. a.
u'
which are usually atsumed constant.
There should be a rigorous,
2_-,
by moderate
the effect of large fluctuations on the
i.e.,
Recomnendations:
anemometer
(subject
to assurance
of
0.5 MHz or higher) and/cr
b.
Continual adjustments of compensating circuit at all times and/or
c. 6.
Heat-transfer calibrations is
7.
Response restoration "a posteriori."
mandatory.
of
the ho:. wire used before and after
Any approximaticns
made In
the reduction
the measurement
formulas should be ex-
plicitly stated and successfully defended (e.g.,
?Y,/aRe - 0,
(Long
hot-wire analysis requires revi-
sion
term) for
The quasi-steady Kovasznay-Morkovir
constant-current
hot-wire
anemometry
in
the
euu'
context
unsteady heat-transfer problem for arbitrary compressible flows. 587
>> eTT',
of
the
etc.').
complete
AD-HOC COMMITTEE NO.
3
Report of the Working Group on Free-Shear Layers Chairman: F. Chamiagne R. Childs Recorder: Members:
S. P. A. R.
Birch Bradshaw Hussain Luxton
H. V. B. 1. K.
Nagib C. Patel Quinn 'Aygnanski Yen
The committee disciissed: "What
is needed to
the near zone
fully specify the initial conditions for
of a free-shear
layer in
order to be
sure we can
compare data with computiations?" T7he free-shear layer or mixing layer will be classified into two categories: planar and 1.
(ý)axisymmetric.
Planar Case a)
o
Specification of Copttoa U
-
U(x,y)
x
-
streamwtse coordinate
y
mean
of
-direction
shear;
eurd
of
height
computational
should be at least greater than 5 shear-layer 1-(Ul
or xX, w~here clature.
-
U 2 )f(Ul + U2 )
domain
thicknesa..ec,
liaing Birch's nomen-
Tiis choice of height should be sufficient for the
vertical ve-'ocity
fluctuations
to vanish and also may ease
any tranapir.3tional boundary conditious iiaroduced to avoid pressure graIlienta. z b)
-
spanwise coordinate; at beuat xX.
Initial Conditions: (1)
A flat-plate, boun'Iary
zero-pressure-gradient
l.ayer
trailing edge..
characterized
by
equilibrium
R() just
turbulent
upstream
of
the
RO chould be greater than 500, and possible
Reynolds nu!i~ber effects on the outer layer may exist for
R.
< 5000. (2)
Laminar
boundary
profille all, (3)
layer--a
good approximation to a Blasius
say, 56 upstream of the trailing edge.
Avoid disturbed boundary layer, artificially
induced
i~xcept for well-documented,
disturbances which may conceivably
useful for time-dependent methods.
..................................................
be
(1)
c)
Free-Stream Turbulence: (1)
If
the
initial
"turbulence" 0.5%,
boundary
in not
layer
likely
is
to
be
turbulent, important
free-stream if
less
tnan
with the possible exception of coupling with acoustic
modes and instabilitics of mixing layer. (2)
If
the initial boundary layer is
laminar,
transition in the
free-shear layer may be affected by free-stream turbulence. d)
Defirition of Trailing Edge--Geometry: (1)
For a one-stream case,
there is
no difference with or with-
out an end plate. (2)
For a two-stream caae,
a maximum included angle of 3' for a
trailing edge with a resulting trailing-edge thickness bein6 an order of magnitude less than the boundary-layer momertum thickness. 2.
Axi-Symmetric Case The computations should be limited to
planar mixing layer; D is
x < 2D,
the .iozzle exit diameter.
if
the obje-t is
to simulat(
a
The initial boundary--layer momen-
tum thickness should be at least two orders of magnitude less then the diameter of the jet nozzle
to allow
full
development
before
the onset of
"a):isymmetrwr"
effects
at
x2D.
riI
589
!i!!:ii!iiii~!!!•iii!iiii!!i !i!i~!i-
. ~~ii
• -.
lm•i!" . . -.i -•
• !• i~ i!
AD-HOC COMMITTEE NO. 4 Report of the Working Group on Turbulence Management and Control of Large-Eddy Structure Chairman: H. Nagib Recorder: R. W'rtp, a I Members:
In in
view of recent
S. D. F. J. J. J.
Bogdonoff Bushnell Champagne Eaton Ferziger Gerrard
importance,
ble influence of the results of the eddy structure control.
ary
their
are
"r 'r for
recommends
sensitivity to
layers
with
v8rialillf
the
controlled
removing
the of
the
and
Lneve
flow-manipulation
butnio
of
that
initial
in
free-shear range
excitation or
evolution
,.-
:*
-
as well as in
wall boundof
of
some
techniques a
schemes be tested for
some of the above cases, layers
particular,
with
it
is
mean flow and the
initial conditions which depart of
the
depend
more
successful
on
detailed
will be required.
Nagib
-
1*
-
-
of
of the
e.g.,
shear
flow manipulators
suggested
that
turbulence
intensi-
the
from the equilibrium
erperiments.
modifications description
990
.'
layers,
boundary
In
of the
H.
.
management and control of large-
from enhanced mixing to augmentation
for
structures.
range of
energy,
including spectral data,
on large-
conditions
representative
turbulent
Conference and these experiments
the advanced computer-prediction
initial
downstream
cases
the possi-
surface drag.
large-scale
Lies be pr'.icted for a are
found
poF'-ible applications
heat transfer to reduction in
"The group
980-81
the above group met to discuss
Examples of this research in
turbulence structures
layers;
Klebanoff LaRue Morel Sandborn Wygnanski
successful attempts at manipulation of the turbulence structure
flow fields of technological
scale
P. J. T. V. I.
the
Since most spectral
Initial
of
distri-
conditions,
I CLOSING DISCUSSION
The Chairmen reports,
and
of the Ad-Hoc Committees
this
was
followed
by
and each Session Chairman presented their
the closing discussion
on Ad-Hoc
Committees
and
Sessions I through XII. REPORTS FROM AD-HOC COMMIITTEES Ad-Hoc Committee No.
1--Hot-Wire Anemometry at Low Mach Numbers
B. Newman reported Lhe results of the committee meeting on hot-wire uncertainties at low Mach numbers and a comparison of laser and hot-wire performance. Questions: P.
Bradshav:
Why do we not use pure platinum wires?
B. Newman: They lack strength. P. BradshAw: Does the lack of a continuous signal
in air with an UDV preclude some
spectral measurements? F.
Durst:
It
depends on the frequencies of interest.
Ad-Hoc Committee No. E.
Reshotko
sonic/supersonic
2--Use of Hot-Wire Anemometers in Compressible Flows
reported on the discussion concerning the use of hot wires in tran-
the available calibration
methods are questionable for sheared flows. so continued hot-wire use is
temperature/density information,
little
and that
He noted the need for very high frequency rerponse,
flows.
An LDA gives
recommended.
Questions: M. Morkovin: bers,
Noted the existence of large scatter of hot-wire data at high Mach num-
particularly
ia
the transonic
range.
He also said the derivation of the
calibration method involves assumptions which make these measurements very uncertain. C. Horstman:
15% uncertcinty would be good here for any hot wire data.
Ad-Hoc Committee No.
3--Free-Shear Layers
C
H. Nagib renorted the discussions regarding the initial conditions for free-shear layer
experiments and computation.
The
extreme
sensitivity
of free-shear layers
disturbances in the initial region was once again noted. Questions: B. Cantwell: P.
Bradshaw:
B. Ramaprian: J. Eaton: P.
WF/ax would be small for large channels anyway. How may a good future experiment be set up?
How was
Bradshaw:
*[Ed.:
Could the channel be divergent to compensate for pressure effects?
Ree - 500
chosen?
From Coles' wake-parameter curve.
See also the conclusions to this volume." 591
•.-
- --: ':.:...
. -
''.....:.
L
: .°'
- -"-'°
.-.
.
-. ---
.- " -. -
- "-?'--
*--i~
.
-
-"
to
S.
Luxton:
The Committee is
trying to give a general guide,
although the conclusions
are not well documented. A minimum R9 of 1000 would be better!
S. Kline:
Low R. is needed for rapid development.
P. Bradshaw:
Ad-Hoc Committee No.
4--TurbuleLice Management and Control of Large-Eddy Structure
The report of this ad-hoc committee was received but there was no further discussion.
REPORTS FROM SESSION CHAIRMEN Reports
from Sessions
I,
II,
VII,
111,
and
X11
were
received
but
invoked
no
further comment from the Confei'ence. Session IV - W. 0.
reynoLds, Chairman
The laminar-flow numerical checks have been withdrawn; to demonstrate mesh-independence
asked
Instead cnmputors will be
by u3sng two different
Specifications
grids.
for Case 0111 will be alt2red. questions: How should code set-up be documented?
J. Murphy:
The Evaluating Committee has yet to decide if
S. Kline:
We will rely on feedback from the Evaluatlon
the Questionnaire will be needed.
See also discussion in Session IV.
Committee and the two teams on "numerics." W. McNally: W. Reynolds:
F.
Computors may not he able to double their grid density. Grid density can always be halved. Does Dr.
G. Lilley:
more information than that in
Gessner propose changes to his specifications?
Gessnel . ';,.t
Session V - A. Roshko, Chairman
"The complete
circular
cylinder
(non-elliptic)
has
been recommended
calculation
quality but are limited in
will
e-tent--only
be
as an entry test case,
requested.
centerplane
* "fuser
in
the
data bank but is
not emphasized
data
data are available.
sure data and total drag are needed for the ellipsoid. retained
Ellipsoid
for which a are
high-
Also,
pres-
Hence the ellipsoid should be
for computation at this
time.
flows might all be optionally computed as boundary-layer flow only if The Samuel-Joubert data should be considered as a boundary layer.t
[Ed.:
Dif-
desired.
This reply has been extended in editing for clarity.]
.'•Ed.: The Samuel-Joubert flow is listed as a simple case (boundary-layer flow). Diffuser flows can be calculated as computors desire or their codes dictate; that is, "as fields or as boundary layers. In no case is the method or computation (field or Indeed, we hope that both approaches will be zonal) specified for the 1981 meeting. used so that we can obtain direct comparisons for evaluation.)
"-'•
592
i.....................
Questions: G. Lilley:
Was the Wadcock flow d.scussed?
A. Roshko:
Yesl
P. Saffman:
7
A. Wadcock may improve the specification of wall conditions.
One should not distinguish steady and unsteady turbulent flows--computors
can consider the flow as they wish. J, Hunt: Why do some data sets not have unsteady data?* G. Xellor: Unsteadiness may be unambiguously defined. A. Perry:
Phase-averaged
flows are difficult to specify and must be operationally
specified. J. Johnston:
Simpson's case is not the only diffuser case; AshJaee's data do not have turbulence but could be useful. S. Kline: I will not recommend Ashjaee's diffuser data since they are our own data, and the data evaluator has not included them. Session VI - E. Reshotko, Complete
Chairman
geometry and initial
conditions for the predictive cases.
conditions will be provided,
but no downstream
Technical oversight of predictive cases will be
provided and is being arranged.
"J. Hint: *'
J. Kim:
Complete hardware and geometry must be specified. Elliptic codes need downstream data for backetep.
P. Bradshaw:
There is no upstream influence in the backatept A status report on each predictive case should be maintained.
W. Reynolds:
*
"J. Eaton:
Reports are planned,
but
even if
some predictive data are not obtained
computations may be compared. Session VIII - H. Nagib, Chairman P. Saffman:
The flows presented by J. Ferziger are not really homogeneous
flows,
so
actual wind-tunnel conditions would be desired. J. Ferziger:
The recent data are very nearly homogeneous,
but many cases have actual
conditions documented. R. Narasimha:
Self-similarity
should not be an input
to the calculation for wall
Jets; this should come out of the computation.
S*[Editor's
note regarding unsteadiness: Many cases involve a request for computation of fluctuations; that is, turbulence and implicitly unsteadiness owing to shocks or flow detachment. As a means of defining a manageable domain for evaluation, flows with unsteady mainstreams have been omitted from this conference. As noted elsewhere, L. Carr and J. McCroskey are tablulating unsteady flows, and they might profitably be addressed in another meeting.] 593 ".L
•
S. Bogdongff.and J. McCroskey,
Sessions IX, X Measurements
for
However,
uncertain.
high-speed
flows,
Chairmen
especially
wall-skin
friction,
are
the trends are reliable and the data should be useful in
highly judging
computer results. A clear distinction between the accuracy of data in
M. Morkovin:
low- and high-speed
necessary and should be flagged.
flow is S. Bogdonoff:
Uigh-speed flows give a better test of turbulence models in some cases
and are very important for this reason and also technologically. Highly uncertain data will not provide a good test for turbulence models.
S. Kline:
J. McCroskey:
This may well
Kline:
S.
Skin-friction uncertainty in high-speed flows has been over-emphasized. be so.
Nevertheless,
the
relatively
large uncertainty
of
high-speed data should be flagged as Morkovin recommends. Session XI - P.
Bradshaw,
Chairman
The CAST 7 case has been discarded. MISCELLANEOUS TOPICS Evaluation Committee
-
H. W. Emmons,
C. Lilley read H. W. Emmons'
Chairman
report (see oelow)
and asked for comment.
Questions: W. Reynolds:
Model constants should be allowed to change via computer algorithm,
G.
long as the computor himself does not subjectively modify constants. The Evaluation Committee recommends that model constants Lilley: changed in different flow situations.
S.
Kline:
must
not
as be
Evaluators should put priorities on flows of the same class to aid compu-
tors. W. Reynolds:
[fEd.:
The timing of t
meeting should be discussed.
This point is covered by the existing Questionnaire which disclosing methods.]
"'computors "
"*
594
is
to be filed by
REPORT OF THE EVALUATION COMMITTEE TO TRE 1980 MEETING*
The problems questionable
if
presented
mwny,
if
by turbulent
any,
that one method can solve all by the computor constitutes We do not expect
poses.
therefore I
flows are numerous,
problems
Ca change of anything,
hope that it
the (distant
in
their
We
which
?)
request
is
the sense
single constant,
to rate
methode because methods designed
or impossible
the methods
will be possible
in
to compare.
various
classes
for the Evaluation
types of methods are the most promising approach in
even a
It
a change of method).
to give a single rating for all
expect
as we have seen.
computing methods exist which are universal in
for different purposes will be difficult We
W. Emmons
H.
Chnirman:
and for
Committee
to become a
various pur-
to suggest which
universal code some
time
future.
that
the evaluators
"Specifications."
bring out the
If
essential
carefully review the
these
can
features
of
be
reduced
in
number of plots number
the complex nature
to
they specify
only
of the
those
flows,
plots
this will
help the Evaluation Committee enormously. We methods
hope
to
examine
the
numerical
to help with our evaluations.
techniques It
is
and
the
clear that
physics
a method that
cases will provide better information for evaluation than a method From evaluation in
the if
above
plans,
it
computations
is
clear
that
we will
be
of
able
are submitted as soon as completed,
to
the is
submitted
used on many
used on only one. do
rather
a
better job of than
all
coming
on July 15th 1981.
141
(Ed.: This report is preliminary to the Final Report of the Evaluation Committee and is intended as input for the Organizing Committee and for computors. The Final Report will appear in the Proceedings of the 1981 Meeting.] 595
.
.
.,.
1
SESSION XIV
Chairman:
G. Sovran
Technical Recorders: R. Jayarainan 0. M. Lilley
I
(J. Lumlcy) Plans for 1.981 and Beyond
596
:>KK~KK:». ~~~"'~~~--
-----------
-.
.
Minutes of Session XIV The Chairman opened the meeting by stating that the purpose of the session was to receive opinions regarding the 1980 conference and suggestions regarding the 1981 conHe stated that
ference for consideration by the Evaluation and Organizing Committees.
"the
major problems
ior
the procedure
196i were
for comparing computational
results
effective disclosure of comput-
with the experimental data and the need for complete,
He posed the following questions as a start to this discuas-
ing methods and programs. sion: I.
Complete Disclosure of Computational Method 1.
Are
there
any
important
pieces
of
commonly
information
missing
from
published descriptions of computational methods? details (on initial and boundary conditions,
Are sufficient
2.
ally given
with
respect
to a
particular
calculation
etc.)
that
it
usu-
can he
replicated by another computor? 3.
What
are some
specific
ideas for formalizing a procedure
to achieve
complete disclosure of the significant factors involved in a particular methud and computation? Questionnaire (for computors to file as disclosure of method)
II.
1. What type of additional questions would you like to ask abcut someone else's method? 2.
What
computor-influences
tionnaire,
if
will not be
identified by
the present ques-
any?
What specific suggestions do you have for improving the questionnaire?
3.
IMl. Evaluation Process How important are numerics in computational methods for complex turbu-
1.
lent flows?
2.
What elements
of computor
technique
(e.g.,
choice of mesh size,
wall
functions) are there that can influence the output from a code, and for what types of flows are they most significant? 3.
What
of evaluation
type(s)
is
(are)
possible/feasible
for
turbulent
computational methods?
IV.
System Checkout what flow will you volunteer to do a complete computation,
1. For
using
data from the magtape file, to check out the mechanics of the system:
597
. . . . . . * ..
..
. .
.
. .
..
. .
. . . . ..-... ..
,
".-
..
... .
....
.
.
•
.
. .
•i
i....
.
.
.
*•..
.
.N -•
.
.
.
.
..
.
.
,,.-
..
-
_
i
.*
i.
Bradshaw:
I wish to
report
a suggestion on a
behalf of Dcunis Bushnell. and turbulence-modeling
It
possible numerical
accuracy
check on
appears to be accepted that the numerical-accuracy
problems are interrelated,
especially for elliptic flows.
Simple partial checks such as mesh reiinemhnt are not necessarily definitive; example,
mesh
refinement
might
not
check
the
influence
of
boundary
for
condition
treatment. Therefore, model
(and
as
a
suggestion,
constants)
for
predictors
several
test
should all use
cases,
mostly
the same
turbulence
elliptic ones.
The
tur-
bulence model specified might b, the k-c or the three-equation model, either with wall function3 or computed directly to the wail. condition
treatment,
etc.,
would be
Grid-resolutlon
and boundary-
requi'ed for each case and should be deter-
mined by the predictors for their individual numerical approaches.
Tne intent is
to provide empirical checks of the numerical approach
where some of
the major influences of turbulence-model inclusion,
as a whole,
such as steep wall gradients
are included. W. Reynolds: so
Is
that
the suggestion that all computors use the same model for one problem,
the differences
in
the
results
would
be
due to
the numerical
methods
used? G. Sovran:
Yes.
J. Murphy.
I suggest that the mixing-length model is the one to be used.
J.
Johnston: used,
I agree with Murphy that a modcl using a mixing-length distribution be
since otherwise many computors using only these models will be excluded.
R. Melnik: in
We want to show that a method using g-1ven turbulence models is consistent
itself.
The computor should demonstrate b/
ics are independent of the mesh size, the Organizing Committee
i.e.,
clarify what is
refining the mesh that his numer-
by using two grids.
required
I suggest that
from computors
in the way of
numerical checks. D. Wilcox:
Something like Bushnell's
Saffman, :' -
but
was discarded,
suggestion was raised at an earlier session b,
since
in
many
cas's
it
would
involve
writing new
codes. G.
Sovran:
There are
two questions:
volved in making the checks, P.
Bradshaw:
Speaking
checks. then
If
and (b)
for Bushnell,
just some of them,
our purposes
(a) would av itordinate even if
dont,
amount of
time be in-
would they prove anything?
not all computeis would be required to do these representing a rac3,! of methods,
will be served.
I feel that
do these checks.,
'.t will be necessary to use a
complicated model rather than a mixing-length model. G. Lilley:
I wish to present to the meeting some matters which arose out of the dis-
cussions
in
the Evaluation
Committee.
It
is
hoped these matters will
receive
comments from attendees at the meeting: 59P
'
-.
-
,•-,•
•
•
.
_ •
...
-•..
_ ..
.';
.
-
.- *,
.
-.
.
•* .
.
.
•.
• '-
.
.
.-•
--
-
-
-
--
-.
."
1..
Did
your
method
approximately 2.
3.
(some
Give CPU time,
mass,
momentum,
energy
precisely
or
only
numerical methods introduce small errors)?
total run time,
bits of storage
required,
digits
used (double-precision?),
machine used for each case submitted.
Does your
some
is
4.
conserve
performance
in
simple
case
more general and powerful than required
look poor
(bits)
because your code
for this case?
Coruputors should rate the test cases they submit in the order of difficulty.
W.
Reynolds:
I
hope
that
what
is
imrlied
terms of computer time rather C. %"."
Lilley:
G. Mellor: G. Sovran: tion8,
in
the
questions
above
is
performance
in
than thu physics.
Yes. I wonder if CPU time is a relevant criterion in a scientific evrluation. This brings in the engineering versus the scientific aspects of compuIta-and there are develo-.Žrs of codes who intentionally sacrifice
accuracy for
srcrter running times. G.
Mellor:
It
appearc
we need
to carefully
calibrate
different
cumputers
in
judging
performance of codes in terms of CPU time.T.
Morel:
CPU
time
comparisono
where convergence
may
not
c,-aightforward
h'e
depends upon how close to the final
in
elliptic
.olutlon
computations
the initial
trial
is. G.
S...W.
Sovran: not
in
In
summarizing
this part of the discussion,
agreement with the proposal I
Paynolc
suggest
that
it
it
appears that computors are
of Bushnell.
might be
possible
to
perform some
useful
numerical
checks as course work at Stanford. G.
Sovran: hoped
that
other
aspect
lems. The
! note there is the
Organizing
of numerics
I understind
tain polass
agreremrent that srzh a proposal is
is
of
make
concerning
Rlýurt by H.
State
Numerical Sulution of Ellipti.2
turbulence
tb..t
will
the
necessary
the solurton
of
arrangements.
is An-
flow prob-
elliptic
_ha' McDonald has prepared a statement on this muatter.
from a Prepared
Predictions--Evaluation
background 0 Advanced
Commf!tee
very desirable and it
of
the
McDonald are as follows:
Art,
1980-81--Flow
Turbulent
Predictions
Flow
Involving
Partial Differential Equations
models
for complex or recirculating
flows
have been
and are
being developed. I
Evaluation
of
the
predictive
capacit-" of
such
turbulence
%odels eventual.ly
re-
quires a mean flow predictio;i of the complex shear flow involved.
0
In making this type of turbulence xodel evaluation, known,
acceptable,
unimportant
numerical error must be at a
level.
599
Ii " .....
.- -.
.i
- -
.-
-.
.
.
.
.
.
.
.
-
*
It.
1968 Stanford Conference
to
produce accurate
ter resources.
able.
system of
lem, are
requiring an
numerics
off-the-shelf the
Obtaining
posed
accuracy of
in
desired
(required?)
schemes
employed was
1968.
complex shear
for
numerics
problems with negligible compu-
the finite-difference
Nimerics were not an issu2
1980s,
the
solutions to posed
numerical
Numerical
unquestioned. In
solution of ODE systems used off-the-shelf
flows are accurate
numerically
not yet
avail-
solutions
the
to
nonlinear partial differential equations may be a difficult
prob-
Hence
numerazs
research
significant
issue in
the
80s,
vo
that
and
development
turbulence
in
itself.
models will not
be
inappropriately
maligned. A prediction
0
constitutes
a combination of governing equations (including boundary model--and
conditions)--turbulence Allocation of
*
predict
flow
blame/credit field
to
requires
solution
(numerical)
constitutive
consideration
procedure. for
components of all
three
failure/achievement
components
(together
to
with
data uncertainty band). 0
Numerical nent
0
sources
must be negligible or tolerable
of error
to remove
this compo-
from consideration.
Governing versial,
equations and
in
and
boukidary
conditions
are
often
standard
and
noncontro-
many cases the data not suspect; hence error can be ascribed to a
turbulence model only after
removal of numerical
aepro imations to boundary conditions)
solution methodology
(ircluding
as a source of error.
Reservations Experience 0
has shown that
User operational significantly
s
I and
contribute
familiarity
to
riate inferences concerning Non-standard
*
(or
detract from)
(or
with numerical methods can
results obtained.
Hence inapprop-
turbulence models have sometimes been drawn.
numerical methodology
quately described
(or lack of it)
tested?)
has often been used and has often been inade-
to permit
Hence an
evaluation.
inability to allo-
cate the source of discrepancy between prediction and measurement occurs. Potential and encountered
0
apparen'
nuwerical
from predictions.
problems of major significance are not always
Comparison
with
data
are
not
necessarily
sole
the
evaluation criterion. Is
It
Important to Have a
"Good"
0
Traditional view--ends solution to a difficult
0
Experience shows
Lhat
tions can result
ii
Numerical Algorithm?
justify means. Approximations are introduced to permit a problem. Algorithm is part of means--hence unimportant. inappropriate
or misused numerical algorithms or approxima-
an erroneous trend.
600 L4
•
. .-
-..
•.
-'
.
,
1
.
-
.,As
a result of inappropriate or misused algorithws, numerical errors
ccntribu,ing either favorably
agreement and/or convergence rate. -
It
may
not
be
. ,reasonable
possible
computer
(how
or unfavorably to thp predictive
Thus the evaluation iL contaminated.
to reduce
resources
solutions contain significunt
the numerical defined?)
errors
to
insignificance
with
with the chosen algorithm for this
particular problem or category of prohlems.
* e
The user community may not be interested in means--the research community ought to be. any
A knowledge and appreciation of the means would seem a prerequisite
realistic
"probable
assessment.
In
thi& way
the user
community
will be
nler~ed
to to
limitationi, and undue uptimisu and disappointments minimized.
"User Operational Skill with Numerical Methods Can Contribute to Results Obtained" .
However, -
problems with numerics might not be discernible in predictions because
Numerical
error can
masquerade
as
physics and
be compensated
out,
but
this may produce an incorrect parametric dependence. -
Boundary and initial condition selection can hold solution "in
place" but
be unrealistic for user. -
Good initial
guess--limited
convergence (divergence?) -
Coarse
mesh
makes
independent.
iterations
hold
solution
"in
place."
Poor
not noticed.
calculation
feasible
yet solution
Large error--slow decrease with mesh
may
not
be
mesh-
size--often mistaker;
for mesh independence. If
0 a
-
Since
numerical problems are not discernible in predictions, are they important? the
Quality of the Numerics
Is
Important,
Can the Quality
of
the Numerics
Be
Assessed? To a degree, Standard
*
Real
yes,
but ...
numerical
problems
might
tests
on a model
introduce
problem are necessary
sufficient
difEerences
but
not
sufficient.
to r91se additional ques-
tions. Numerical algorithm often very complex,
0
One
cannot
done,
assess
what
Danger of tail.
algorithm
boundary conditions
the solution is •
the
non-standard, and incompletely described.
without
are applied,
"I've tried that and it
... "
Prior experience may or may not be relevant.
:
statement
how implemented,
didn't work
1101
::
very complete
of
rhat is
and how sensitive
to key numerical approximations.
•
::
a
:
OI
due to a sensitivity to de-
I..
CONCLUDINU REMARKS flow predictions numerical error levels must be known
For these complex turbulent
to be correctly
turbulence model and predictive accuracy
and acceptable to permit evaluated. *
Labor
to make
the aosessment
of
the possible
or probable '81
rors and to provide supporting evidence for Stanford *
Even without such assurance Stanford nitior, and
consequent
validation)
in
the
of
exposure
'81
could result in
the
way be overwhelming. a more widespread recog-
rnethbc'ol-gy
numerical
(with appropriate
(and a consequent reduction in
literature
technical
level of numerical er-
the
ber
of maligned turbulence modelsl)
P.
Bradshaw:
H.
McDonald:
McDonald suggesting checks are cnin.-cessary?
Is
checks.
What
I
Even
with
is
method
is
am suggesting full
a
disclosure
not
how
know
his
own
sensitive
his
Hence there will be some constraints
the approximations.
to some of
may
computor
wiil make
analyst
the numerical
that
on
what can be asked from computors for the 1981 Conference.
"sary
developing codes
We are
P. Bradshaw: for
us
to
the
separate
for
effects
the
engineering
of
numerics
community and
from
the
is
it
inaccuracies
necesthe
of
turbulence models. G.
Mellor: satisfy time,
S.
computor
Each
Launder:
I
that
and
line;
remind
expect
the
to
1981
on his method
checks
to
will take a long
these checks
for September
14-18,
1981,
but could
about
that
50
prospective
computors
have
Kline and expressed the desire to compute most flows
complete
in
these
Also,
time
for
the
July
deadline
for
the
only halt the cases are completed these
even if
task for evaluation.
a show of hands.
for
deadline;
of the
meeting
a difficult
present (Asked
G. Sovran: July
to
1981 Conference.
will still
of
Christmas 1981 or June 1982.
wish
they
September
added that
currently planned
replied to Professor
already
number
large
(He
accuracy.
The 1.981 meeting is
be delayed until B.
its
a
1981 too soon for the next conference?)
so is
Kline:
of
himsel'
be making
will
none reported
There were that
they
they could meet the
16 who said not
could
meet
July
the
1981 dead-
4 stated they would prefer a later date for the proposed Septem-
16,
ber 1981 Conference). Several
discussors
would
be
an
similarly. It
task. 70-
thereby
(Kline, ongoing
That
is,
resulting
program,
the
the
meeting
1981
both
status
for
users
that
just
evaluation
(unlike
can and hopefully will provide clarify
Felt
Launder):
Revnolds,
1968)
will
as
might not
the
Data
well
be
and
profitable
regarded
largely finish
snapshot cf the state
a
Library
avenues
the
of the art and of
further
re-
searches. 602
S~~
--..
-
•
-
-
--
.
---
..................
,-=,
,-,••.,•_••..•\.....
'•
E. Reshotko:
The numerical evaluation of codes I wonder
experiments.
if
they
is
very similar to the evaluation of
could be tested
in
a way analogous
to that of
Moffat's Uncertainty Analysis. P.
Saffman:
W. Rodi:
I suggest that the codes be tested for different sensitivities.
This is automatically done when the same code (like TEACH)
is used for difi
ferent problems. Editor's Note: As a result of this and othe; numerics,
discussions during the meeting concerning checks on
two actions have been planned regarding numerical checks for the 1981 meet-
ing. 1.
Computors will be asked to do a halving of mesh size or, not possible, sults (if
to do a
doubling,
if
halving is
in either case to report Lhe re-
and
possible on central cases to give dense results for compari-
son). 2.
study problems of numerics:
Two groups of computors will specifically one group chester
will be coordinated by
and
Ferziger,
J.
Karlsruhe; Stege-.,
the
B.
other
E.
Launder
group
will
and "1. Reynolds
at
and W. Rodi be
coordir.tted
Stanford.
The
group will produce
results for a common (orobably
various numerics.
Ferziger et al. may do similar work,
k-E)
at
Mar.by
i.
bLunder/Rod.l model using but will also
study results and disclosures as received to generate further ideas re numerical
checks
if
possible.
B. E.
Launder will coordinate overall
for the Ovganizing Committee. These
steps
than what is
on checking numerics
desired
(needed?),
The problem of numerics is
by
the Organizing CommIttee
as
less
of great importance and will be given serious ongoin& conAs on other problems arising from the work of
we expect that considerable learning will occur before the end of the Suggestions on this topic will be welcome.
1981 meeting. S.
seen
but as the best that current knowledge can suggest.
sideration as results are accumulated. the Conference,
are
Birch and W. Reynolds:
C-mputors will need to fully understand their codes so that
1-
they can fully dislose their methods during the coming year. B. Launder: S.
Kline:
All details of wall matching must be completely reported. Will Brian Launder please look carefully into this aspect of the Question-
naire and add specific questions on wall matching? J.
Hunt:
The
Questionnaire
does
not
address methods
other than Reynolds
equation methods. 603
-~C
.
transport
G.
Hunt propose some specific
Will Prof.
Sovran:
in
ods which can be incorporated G.
Sovran,
On
another
topic,
we
juest'ons on these additional meth-
the Questionnaire?
would
volunteers
appreciate
who
will
try
vome
of
these flows at an early stage so any problems that atile can be clariFied for the rest of the computors. The following volunteered: Flows 0210,
Bradshaw:
All the boundary layer cases,
Dvorak: Rodi:
Separated airfoil, Flow 0440. Boundary layers with wall curvature, Flow 0260.
Wilcox
Boundary-layer
cases,
compressible
number and wall
temperature,
ers, Flows 0250,
0810, 0820.
0630,
Flow 0230. and wall jets,
Cf
with
Hach
boundary
lay-
variation
three-dimensional
Flows 0140,
Flows preýsented by Simpson,
Murphy:
0240, 0620,
0430.
Cook/rirmin: Transonic airfoil, Flow 0862. Square duct (Gessner),
Rodi: S.
Kline:
Stated
JNovember
that
1980.
He
Lhe
expressed
sults of these trials
S. tially
Kline closed all
first
Flow 0110.
package the
of flow cases will be dispatched
hope
that
would submit
the
late re-
as soon as possible.
the conference with a vote of
the attendees at
the volu te:rs
in
the 1980 meeting.
604
thanks
for the hard work of essen-
I .
CONCLUSIONS
(1)
The 1980 Meeting of the AFOSR-HTTM 1980-81 Stanford
Conference was a cooperative
effort of a large fraction of the experimental fluid mechanics research community aimed at reaching a consensus concerning: "what currently available experimental data for turbulent flows are sufficiently trustworthy to be used as inputs to turbulence modeling, and/or a basis for standard 'trials' for checking outputs from computations?" The Conference is
best viewed as a learning process,
a way of accelerating under-
standing and research progress. (2)
The meeting demonstrated
that increased
and
fluid
experimentalists
"experiment
in
and computation,
by the paper on
interaction
mechanics
to close
is the
loop
and thereby speed progress.
Uncertainty
Analysis"
needed between computors iteratively between
The framework provided
can inform this process,
and is
strongly
recommended for use. (3)
The Working Groups and general discussinn problems
of
present
concern
in
at Lhe 1980 Meeting highlighted
experimental
fluid
mechanics.
Among
many
those dis%
cussed were
(4)
(i)
the accuracy of hot-wire measurements in subsonic, transonic, and supersonic flows, and the need for redundancy checks for laserdoppler anemometers;
(ii)
uncertainty analysis for skin-friction tubes in complex tubulent flows;
(iii)
whether shock waves are ever truly steady even in weakly turbulent interacting flows, or whether some high-speed jitter is alvy''ys present. If high-speed jitter exists, what are the resulting effects on the turbulence structure and the overall characteristics of the flow?
measurements
with
PiEzton
Although the 1980 Meeting confirmed that many good data sets are available, data
sets
flows.
of high quality are required Redundant
data
sets,
redundant
particularly
measurements,
and
improved
checks
The 1980 Meeting of the Conference made recommendations concerning: (i)
the planning of record experiments checking of computations;
(ii)
improved care needed in setting up the initial ann tions of record experiments;
for
turbulence
modeling
.----------
.,.-
and
boundary condi-
605
.
more
for very complex turbulent
experimental control zre also required. (5)
71
.
on
IF'.I (iii)
This
the improved use of uncertainty analysis through appropriate back checks at various stages of experimental work. use of uncertainty
experiments,
not
but also because
(6)
there is
compressible
flow data,
ate
feedback
modes.
8630,
and 8640.)
All of
"clear consensus"
be
out
of
as well also
as
the use of
date
comment
by
relatively
soon.
Kline
progress
on
we
on a sound and expanding provide
a
flow analysis
Data Base. current
in
of
appropri-
data
Discussion
of
believe
the
Flows
in
1981
1980-81
turbulence models and numerical
directing future research.
complex turbulent
analysis
The "state of the art"
Nevertheless,
sizes
should
instrumentation
the 1980 Meeting know that CFD is
and thereby help in
Meeting
to perform,
in
procedures
1980
on tru3tworthy
flow
J.
will delineate the state of the art in
the
compressible
S.
branch of fluid dynamics.
in
in
and difficult
uncertainty
Conference
that
important
This suggests careful preplanning and cross-checking
us who were privileged to participate
dependent "'
less
(See
an active and expanding
will
particularly
only because they are more expensive
and the resulting data.
8610,
analysis is
feed-
and prediction
The data base
This work again emphais
library created
and a
mechanism for
vitally through future
expansion.
60
4
-
.
.
S
.
.*..*-
.
LIST OF PARTICIPANTS, No. in Photo B.41
"
*
Tasks
Affiliation or Address
Name Dr. Mukund Acharya
Fluid Mechanics Group Brown, Boveri & Company, CH-5405 Baden-Dittwil SWITZERLAND
Data Eval. Ltd.
8.2
Mr. Eric W. Adams
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide; Tech. Rec.
A.30
Mr. Bahram Afshari
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide; Tech.
P.40
Dr.
Sandia Laboratories Livermore, CA 94550
Computor
Mr. Harry Bailey
NASA-Ames Research Center "Mail Stop 2023.-1 Moffett Field, CA 94035
Computor
A.19
Mr. Jorge Bardina
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide
A.13
Mr. Juan G. Bardina
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide
Dept. of Aeronautics Imperial College Prince Consort Road London SW7 2BY, ENGLAND Inst. de MHcanique Statistique de la Turbulence 13, avenue du Giin6ral Leclerc Marseille 13003, FRANCE
Review Comm.
NASA-Ames Research Center %ail Stop 229-1 Moffett Field, CA 94035
Computor
W. T. Ashurst
-
Dr. P.
Bearman
Dr.
Claude Beguier
Dr.
Muriel Y. Bergman
2
1980 MEETING ON DATA
Computor; Data Taker
B.30
Dr.
Claude Berner
Aerospace & Mech. Eng. Dept. The University of Arizona Tucson, AZ 85721
Discussor
A.50
Dr.
Stanley F.
Org. L-7150, Mail Stop 41-52 Boeing Military Airplane Co. P. 0. Box 3999 Seattle, WA 98124
Data Eval.
8.23
Prof.
Birch
S. M. Bogdonoff
A.78
Prof.
Peter Bradshaw
Dept. of Aeronaut./Mech. Princeton University Princeton, NJ 08544
Eng.
Chairman
Org. Rev. Data Data
Aeronautics Department Imperial College Prince Consort Road London, SW7 2BY, ENGLAND
Rec.
Comm.; Chairman; Comm. Chairman; Eval.; Taker
607
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-
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-
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.
in
Brune
A.25
Mr.
Guenter
A.39
Dr.
nennis Bushnell
A.8
Prof.
A.31
Mr.
Robert
B.20
Dr.
Lawrence W. Carr
A.35
Dr.
Ian P.
B.28
Prof.
Brian Cantwell
F.
Carella
Castro
H. Champagne
Dr.
.•
.
-
•
-
Dean R.
Chapman
Chevray
A.7
Prof.
R.
A.4
Prof.
M. Childs
A.16
Mr.
Robert Childs
A.27
Dr.
Thomas
J. Coakley
Dr.
David J. Cockrell
A.2
Prof.
A.82
Dr.
J.
-
• .
-
4.
'
'
Donald Coles
Cousteix
-.
•
-..
.
Tasks
Boeing Military Airplane Co. P. 0. Box 3707, Mail Stop 3N-29 98124 Seattle, WA
Discussor
NASA-Langley Research Center Hampton, VA 23665
Discussor
Aero & Astro Department Stanford University Stanford, CA 94305
Org. Comm.; Supervisor Data Library; Data Eval.
Aero & Astro Department Stanford University Stanford, CA 94305
Aide; Tech. Data Entry
U.S. Army Ae:omechanics Lab. NASA-Ames Research Center Mail Stop 215-1 Moffett Field, CA 94035
Chairman; Discussor; Data Eval.
Dept. of Mech. Eng. Guildford Surrey, University of5XH, ENGLAkND Surrey, GU2
Review Comm.; Tech. Rec.
Aerosp. & Mech. Eng. Dept. University of Arizona Tucson, AZ 85721 NASA-Ames Research Center
Special Comm.
Mail Stop 200-4 Moffett Field, CA
Discussor
Eval.
Rec.;
Gomm.;
94035
Dept. of Mechanics State University of New York Stony Brook, NY 11790 Dept. of Mech. Eng. University of Washington
Computor; Data Taker Discussor
98105
Seattle, WA
B.25
-• /
Affiliation or Address
Name
Photo
.
Aide; Tech.
Mech. Eng. Department Stanford University Stanford, CA 94305 NASA-Ames Research Center Mail Stop 229-i Moffett Field, CA
Computor
94035 Rec.; Reviews
Department of Engineering The University Leicester, LEI 7RH, ENGLAND
Tech. Tech.
GALCIT 321 Guggenheim Laboratory Calif. Inst. of Technology
Data Eval.;
Pasadena, CA CERT/DERAT
91125
2, avenue Edouard Belin Complex Aerospatiale, B.P. 31055 Toulouse, FRANCE
608
Rec.
Review Comm. 4025
-.-
.-
.
-"
- '~No.
in..-
"Photo
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide; Tech.
Atkins Research & Development Woodcote Grove, Ashley Road Epsom, Surrey, KT18 5BW, ENGLAN•D
Data Eval.
Antony Demetriades
Dept. of %Mech. Eng. 220 Roberts Montana State University Bozeman, MT 59717
Special Comm.
Pius Drescher
Brown Boveri & Company. Dept. TX CH-5401, Baden-D~ttwil SWITZERLAND
B.5
Mr.
Andrew D.
A.58
Dr.
R.
B.42
Dr.
A.54
Mr.
B.48
Prof.
A.75
Dr.
B.49
Prof.
B.9
Ms.
Tasks
Affiliation or Address
Name
F.
B.
Cutler
Dean
Franz Durst
A.
Dvorak
John Eaton
Pam Eibeck
Ltd.
Sonderforschungsbereich 80 Universitgt Karlsruhe Kaisurstrasse 12 D 75 Karlsruhe 1, WEST GERMANY President Analytical 100-116th Bellevue,
& Dir. of Research Methods, Inc. Avenue S. E. WA 98004
Data Eval.
Review Comm.
Tech. Rec.; Computor; Discussor
Mech. Eng. Department Stanford University Stanford, CA 94305
Host Comm.; Data Eval.; Coord: Aides
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide; Tec'..
"KI Rec. 21
B.29
Prof.
H. W. Emmons
Room 308, Pierce Hall Harvard University Cambridge, MA 02138
Chairman, Eval. Comm.
A.26
Prof.
Torstein K. Fannel~p
Div. of Aero & Gas Dynamics Norges Tekniske H6gskole Higskoleringen I N 7034 Trondheim, NORWAY
Data Taker
Prof.
A.
de M~canique Statistique inst. de la Turbulence
Computor; Data Taker
Favre
Rec.
.
13, avenue du Glngral Leclerc Marseille 13003, FRANCE Mr.
A.11
B.26
Bill Feiereisen
Prof.
Prof.
H.
Fernholz
Joel Ferziger
Al
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide
fNr Herman-Fottinger Institut Thermo- und Fluiddynamik Technische Universit~t D-1000 Berlin 12, WEST GEýU4ANY
Data Taker
Mech. Eng. Department Stanford University Stanford, CA 94305
Host Comm.; Data Eval.
-.
609 609
--
No. in Photo B.33
Tasks
AMfiliatinn or Address
Name Dr. Anthony W. Fiore
Division
AFWAL/FIMG Aeromech.
Discussor
Flight Dynamics Laboratory Wright-Patterson AFB, OH 45433
B.11
Mr.
M. C. P. Firmin
Aerodynamics Department
Discussor
Royal Aircraft Establishment Farnborough, Hampshire GU14 6TD, ENGLAND A.15
Mr.
Mauricio N. Frota
A.6
Jack H.
Prof.
Gerrard
Mech. Eng. Department Stanford University
Aide
Dept. of Mechs. of Fluids University of Manchester
Tech. Rec.; Rev. Comm.
Stanford,
CA
94305
Manchester M13 9PL, ENGLAND A,9
Prof.
Fred Gessner
Dept. of Mech. Eng., FU-10 University of Washington Seattle, WA 98195
Data Eval.; Rev. Comm.
A.3
Prof.
Isaac
Dept. of Mech. & Aerosp. Eng. Case Western Reserve University Cleveland, OH 44106
Discussor
A.40
Dr.
Masinski fakultet Omladinsko Setaliste
Computor
K.
Creber
Hanjali6
YOGOSLAVIA
71000 Sarajevo, A.59
Dr.
Robert Hantman
Mech. Branch. G.E. Company Bldg. K-I, P. 0. Box 8 Schenectady, NY 12301
Tech.
A.65
Dr.
H. Higuchi
NASA-Ames Research Center Mail Stop 229-1 Moffett Field, CA 94035
Discussor
Head, Mech. Eng. Dept. The Univ. of British Columbia
Eval.
Prof.
Philip G.
Hill
Rec.
Comm,.
Vancouver, B.C., V6T 1W5, CANADA B-19
Prof.
B.12
Dr.
S.
C. '.
Honami
Horetman
Science Univ. of Tokyo Kagurazaka, Sinju-ku Tokyo, 162, JAPAN
Data Eval.; Pictorial Summ.
NASA-Ames Research Center
Data Eval.
Mail Stop 229-1 ""-Moffett Field, CA
B.10
Dr.* Thotuas T. Huang
Code 1552 David Taylor Naval Ship R & D
"Bethesda, A.1
Dr.
J.
A.
C. Humphrey
"A.76
Mr. D.
A.
Humphreys
MD
L
94035
Discussor
20084
Dept. of Mech. Eng. University of California Berkeley, CA 94720
Tech. Rec.; Data Taker
Aerodynamics Dept. Aeronaut. Res. Inst. of Sweden "V'. 0. Box 11021 S-161 11 Bromma, SWEDEN
Data Eval.; Discussor
"610
i*
"
No.
in
Photo A.55
Name Dr.
Affiliation or Address
Ching Hung
NASA-Ames
Tasks
Research Center
Computor
Mail Stop 202A-1 Moffett Field, CA
A.47
Mr.
Julian C.
94035 CIRES University of Colorado Boulder, CO 80309
R. Hunt
-
B.31
Prof.
A.
K.
M. F.
Dept.
of Mech. Eng. University of Houston
Hussain
Hnueton, TX A.71
Discussor
Tech. Rec.; Discussor
77004
Dr.
Kuneo Irabu
Mech. Eng. Dept. University of Ryukyus Tonokura-cho, Naha Okinawa, JAPAN
Discussor
A.34
P..
Ramesh Jayaraman
Mech.
Aide
A.33
Mr.
Ranga Jayaraman
Eng. Department Stanford University Stanford, CA 94305 Mech. Eng. Department
Charles E.
Stanford University Stanford, CA 94305 AFWAL/FIMM
Dr. A.69
B.14
A.53
Jobe
Dennis Johnson
Prof.
J.
Prof. J.
P.
Host Comm.;
Stanford University
Data Eval.;
Virginia Polytechnic A.52
Prof.
Blacksburg, VA Peter N. Joubert
Dean William M. Kays
B.45
Dr.
Mr.
P.
of Mech. Eng. The University of Melbourne Parkville, Victoria 3052 AUSTRALIA
Tech.
School of Engineering Stanford University
Rev.
A.83
Prof.
S.
J.
Building YM
Gaithersburg, MD 20760 Motoren- und Turbinen
Dr.-Ing. Armin Klein
Union Minchen GmbH D-8000 Minchen, WEST GERMANY Mech. Eng. Department
Kline
Stanford University Stanford, CA 94305
Rec.
Comm.
Discussor
Chairman; Data Taker
Review Comm.
Chairman,
Org. Comm.; Host Comm.; Rev. Comm. Chairman
611
S.
..
.
.
.
Chairman
Stop 229-1
Room 109,
'.
.
Inst.
Moffett Field, CA 94035 National Bureau of Standards
S. Klebanoff
Chairman;
24061
Dept.
Mail
A.67
Rev. Comm. Tech. Rec.
Stanford, CA 94305 NASA-Ames Research Center
John Kim
Discussor
Moffett Field, 94035 Mech. Eng. Department
Stanford, CA 96305 Dept. of Mech. Eng.
B. Jones
Rec.
45433
NASA-Ames Research Center Mail Stop 227-8
Johnston
Tech.
Review Comm.
Wright-Patterson AFB, OH Dr.
Aide;
.i
"i
"
S
No.
in
Photo
I,
Name
Affillation or Address
Mr.
D. M. Kuehn
NASA-Ames Research Center Mail Stop 229-1 Moffett Field, CA 94035
rlata Taker
Dr.
John LaRue
Dept. of Appl. Mech. P. 0. Eox 109 Univ. of California, La Jolla, CA 92037
Data Taker
San Diego Org. Comm.; Chairman; Data Eval.;. Rev. Comm. Chairman
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide; Tech. Rec.
Dr. Anthony Leonard
NASA-Ames Research Center Mail Stop 202A-1 Moffeýtt Field, CA 94035
Computov
A.42
Dr.
ARAP. Inc. P. o. Box 2229 Princeton, NJ 08540
Computor
B.22
Prof.
G. M. Lilley
Dept. of Aero and Astronautics University of Southampton Southampton, ENGLAND
Eval. Tech. Tech.
A,18
Prof.
John L.
Sibley Scn. of Mech/Aero Eng. 238 Upson Hall Cornell University Ithaca, NY 14853
Chairman; Rev. Comm. Chairman
A.12
Prof. R. E. Luxton
Dept. of Mech. Eng. University of Adelaide GPO Box 498, Adelaide S. Australia 5001, AUSTRALIA
Discuesor
A.23
Mr.
Mech. Eng. Department Stanford University Stanford, CA 94305
Aide
Prof.
A.45
Mr.
B.44
B.38
Brian Launder
Mario Lee
Steve Lewellen
Lumley
Aristoteles
Joseph G. Marvin
NASA-Ames Research Center Mail Stop 229-1 Moffett Field, CA ?4035
Rev. Comm.; Gov't Monitor
Dr.
J.
Ecole Centrale de Lyon "B.P. No. 17 69130 Ecully, FRANCE
Rev. Comm.; Computor
U.S. Army Aeromechanics Lab NASA-Ame3 Research Center Mail Stop 215-1 Moffett Field, CA 94035
Chairman; Discussor
Scientific Research Assoc. P. 0. Boy 498 Glastonbury, CT 06033
Computor
Mathieu
H. McDonald
612
...
Comm.; Rec.; Reviews
Mr.
Dr. W. J. McCroakey
S-Dr.
Scl.
University of Manchester Inst. of Sci. & Tech. .Mech. Eng. Dept. Sackville Street, P. 0. Box 88 Manchester M60 1QD, ENGLAND
A.74
Lyrio
"-.:.
TaAks
L
No. in Photo
Same
Afiliation or Address
Tasks
A.21
Dr. William D. McNally
Chie~f, Comp. Fluid Mech. Branch NkSA-Lewis Research Cent'ar Mail Stý-" 5-9 Clevelar.d, OH 44135
Gov't Monitor
B.21
Dr. Unweel Kehta
Computor
B.13
Dr. Hans Ulrich
NASA-Amee Research Center Mail. Stop 202A-1 '(offett Field, CA 94035 DlFVLR-AVA, Institut f~ir Exp. Str~muingamechianik Buisenstrosae 10 D-34CO G~tringen, WEST GERMANY
Meier
Cociputor; Tape Library Acce..s
A-51
Prof. George Mellor
Geophys. Fluid Dyn. Lab. P. 0. Box 308 Princeton University Princeton, NJ 08540
Rev. Comm.; Computor
B.7
Dr. R. E. Melnik
Resea'vch Dept., M/SA-08-35 Grumman Aerospace Corp.
Data Eva].; Computor
Bethpage, NY B.37
11714
Dr. H. Ha Minh
Inst. de i{6canique des Fluides 2, rue (Amichel 21071 Toulouse Cedex, FRANCE
Computor
Prof. R. J. Haff&t
Mech. Eng. Department Stanfcrd University Stanford, CA 94305
Host Comm.; Speaker
Dr. Parviz Momn
Mech. Eng. Departmeiit Stanford University Stanford, CA 94305
Tech, Rec.
Dr. Thomas Mo~rel
Fluid Dynaraics Dept., Res. Labs. General Motors Tech. Center 12 Mile & Mound Roads Warren, MI 48090
Tech. Rec., Computor
A.14
Dr. Mark Markovin
1104 Linden Avenue 0-Ok Park, IL 60302
Eval. Comm.; Rev. Comm.
B-16
Mr. Alan Morse
Dept. of Mech. Eng. Imperial College London SIA7 2BY, ENGLAND
Date Eval.
A-68
Prof. Rai. L. Moses
Depý.. of Mecil. Eng. Virginia Polytechnic !not. Blacksburg, VA 24061
Tech. Re'c.; Rev. Comm.; Compurur
A-38
Mr. John Murphy
NASA-Ames Recearch Center Mail qtot2 227-8 Moffett lý1eld, CA 94035
Computor
Prof. It.Naglib
Mech. &,Aerospace Eng. l11inoia Institute or Tech. Chicago, IL 60616
Tech. Rec.; Discussor
Prof. Roddam Naranimha
Dept. of Aeronauticnl Eng. Indian lnsitirute of Scicnce Bangalore 560 012 INDIA
Rev. Comm.; Computor
N
*A.48
48.3 8.35
613
No.
in Name
Photo A.77
A.44 =.•-•.P.O0.
Dr.
Dr.
Affiliation or Address
Barry G.
F.
K.
Newman
Owen
Dept. of Mech. Eng. McGill University 817 Sherbrooke St. West Montreal, P.Q. H3A 2K6,
Tasks Rev. Comm.; Discussor CANADA
Consultant Box 1697 Palo Alto,
CA
Data Taker 94302
Prof.
Pradip Parikh
Mech. Eng. Department SLanford University Stanford, CA 94305
Tech.
A.66
Prof.
V. C.
Iowa Inst. of Hydraulic Res. University of Iowa Iowa City, IA 52240
Chairman; Data Eval.; Rev. Comm.; Discussor
A.80
Dr.
G.
Boeing Military Airplane Co. P. 0. Box 3999, Mail Stop 4152 Seattle, WA 98124
Computor
A.79
Dr.
David Peake
Sr. Research Associate NASA-Ames Research Center M¶all Stop 227-8 Moffett Field, CA 94035
Dsta Taker
Dept. of Mech. Eng. University of Melbourne Parkville, Victoria 3052 AUSTRALIA
Data Taker
Prof.
B.34
Dr.
C.
A.
Patel
Paynter
E.
Perry
Stuart L. Petrie
Prof.
Felix J. Pierce
A.41
Prof.
Mr.
A.22
R.
L.
H.
Pletcher
G. Pre&1ey
Hr. Steve W. Pronchick
A.60
"A.62
Dr.
Brian Quinn
Prof.
3. R. Ramaprian
B.47
Prof.
Eli Reshotko
Professor and Chairman Dept. Aero. and Astronaut. The Ohio State University 2036 Neil Avenue Columbus, OH 43210
Rec.
Data Taker Eng.
Dept. of Mech. Eng. Virginia ?olytechnic Institute Blacksburg, VA 24061
Rev. Comm.; Computor
Dept. of Mach. Eng. Iowa State University Ames, IA 50011
Computor
NA-A-Ames Research Center Mail Stop 227-8 94035 Moffett Field, CA
Rev.
Mech. Eng. Department
Aide; Tech. Rec.
Comm.
Stanford University Stanford, CA 94305 ARAP, Inc. Princeton,
Computor NJ
08540
Inst. of Hydraulic- Res. The Universi(y of Iowa Iowa City, IA 52242
Rev.
Dept. of Mech. & Aerosp. Eng. Case/Wentern Reserve Univ. Cleveland, OH 44106
Org. Comm.; Chairman; Data E':al.; Rev. Comm. Chairman
614
Comm.
I
ii
No.
in _o
Photc
A.20
Name
Affiliation or Address
Prof. W. C. Reynolds
Tasks
Mach. Eng. Department
Eval. Comm.;
Stanford University Stanford, CA 94305
Chairman; Host Comm.; Rev. Comm. Chairman
4925 Kathryn Circle S.E. Albuquerque, NM 87108
Eval. Comm.; Compt'..or
Dr.
P.
A.63
Dr.
Wolfgang Rodi
Sonderforschungsbereich 80 Universitit Karlsruhe Kaiseratrasse 12 D 75 Karlsruhe 1, WEST GERMANY
Data Eval.. Computor
B.6
Dr.
Anatol Roshko
Guggenheim Lab. 105-50 Calif. Inst. of Technology Pasadena, CA 91125
Chairman; Rev. Comm.
J.
Roache
Chairman
A.56
Mr.
Morris Rubesin
NASA-Ames Research Center Mail Stop 202A-1 Moffett Field, CA 94035
Org. Comm.; Data Eva..; Rev. Comm. Chairman
A.5
Dr.
Philip G.
Appl.
Diacunsor
"Saffman
Math.,
Calif. Inst, of Technology Pasadena,
"B.13
Prof.
V. A.
A.81
rrof.
Joe Schetz
Dr.
B.15
H. C.
Prof.
Sandborn
Seetharam
Y. Senoo
Firestone 217-50
In
CA
91125
Dept. of Civil Eng. Engineering Res. Center Colorado State University "Fort Collins, CO 80521
Data Taker
Dept. of Aerosp. & Ocean Eng. Virginia Polytechnic Inst. & State University "Blacksburg, VA 20461
Computor
Boeing Military Airplane Co. P. 0. Box 3999, Mail Stop 3N-43 Seattle, WA 98124
Data Taker
Red. Inst. of Ind. Science Kyushu University Hakozaki, Fukuoka-si
Computor
812 JAPAN *-.
A.24
Dr.
Gary S.
Settles
Gas Dynamics Laboratory Forrestal Campus, Princeton Univ.
Princeton, NJ Mr. Terry Simon
Prof.
A.36
Dr.
A.
Roger L. Simpson
J.
08544
Mech. Eng. Department Stanford University
Stanford, CA A.61
Smits
Data Taker
Data Eval.
94305
Civil & Mechanical Eng. Southern Methodist Univ.
Data Eval.; Rev. Comm.;
Dallas,
Discussor
TX
75275
Dept. of Mech. Eng. University of Melbourne Parkville, Victoria 3052
Discussor
AUSTRALIA A.64
Dr.
Rone•Id M. C.
So
Mechanics Branch General Electric Company Bldg. K-I, P. 0. Box 8 Schenectady, NY 12301
Tech. Rec.: Data Taker
615
SI
No. in Photm A.10
Name
Dr.
Affiliation or Address
reter M. Sockol
Research Eng. Comp. Fluid Mech.
Tasks Gov't.
Monitor
Branch
NASA-Lewis Research Center, MS 5-9 Cleveland,
Dr. Gino Sovran
Prof.
K. R.
Dept.
Sreenivasan
44135
Fluid Dynamics Dept. Research Laboratories General Motors Technical Center 12 Mile & Mounds Roads Warren,
A.57
OH
MI
48090
of Eng.
& Appl.
Joseph Stegr
Mr. Tony Straws
5.4
Mr.
Roger C.
Strawn
Prof.
A.32
Mr.
Robert L. Street
Ram Subbarao
CA
Eval.
CA
CA
B.46
E.
Dr. Y.
B.43
Prof.
B.17
Mr.
B.24
Mr.
P.
Sutton
Tassa
H. Thomann
Rec.;
Aide; Tech.
Rec.
94305
Civil Eng. Deartment Stanford University Stanford, CA 94305
Discussor
Mech.
Aide; Tech.
Eng.
Department
Stanford, CA Prof.
Aide; Tech. Data Entry
94365'
Stanford University A.17
Comm.
94087
Mech. Eng. Department !'tanford University Stanford,
Comm.
21218
Aero and Astro Department Stanford University Stanford,
Data Eva!.; Rev.
Flow Simulations, Inc. 298 S. Sunnyvale Avenue
Sunnyvale, A.43
Science
Yale University "P. 0. Box 2159
New Haven, CT Mr.
Org. Comm.; Chairman; Rev. Comm. Chairman
94305
Univ. Eng. Dept. Trumpington Street Cambridge, CB2 lPZ, Lockheed Dept. 72-74, GEORGIA
Rec.;
Data Entry Presentor ENGLAND Computor
Zone 404
Institut fc Aerodynamik ETH-Zentrum 8092 Zurich, SWITZERLAND
Data Taker
Murr-y Tobak
NASA-Ames Research Center Mail Stop N234-1 Moffett Field, CA 94035
Computor
Cam Tropea
Sonderforschungsbereich Universitht Karlsruhe
Data Taker
80
Kaiserstrasse 12 D-75 Karlsruhe
A.49
Dr.
T.
Dr.
Hiromasa Ueda
J.
Tyson
1,
WEST GERMANY
Energy and Env. Res. Corp. 2400 Michelson Drive Irvine, CA 92715
Computor
NatI. Inst. for Env. Studies P. 0. Yatabe, Tsukuba, Ibaraki 305 JAPAN
Data Taker
616
..
. .
.
.± -- . .
...
.
.
.
.
No. in Photo
Name
A.73
Dr.
A.28
B.
Affiliation or Address
van den Berg
Tasks
National Aerospace Lab NLR Authony Fokkerweg 2 Amsterdam - 1017, NETHERLANDS
Data Eval.
Dr. John Viegas
NASA-Ames Research Center Mail Stop 229-1 Moffett Field, CA 94035
Computor
B.36
Dr.
Aero & Astro Department Stanford University Stanford, CA 94305
Data Taker
A.29
Dr. Klan Wadcock
NASA-Ames Research Center
Data Eval.; Data Taker
Mr.
Mail Stop 247-1 Moffett Field, CA 94035 Mech. Eng. Department
B.8
P.
B.1
Dr.
Viswanath
Russ V.
Prof.
A.70
R.
J.
D. C.
Prof.
I.
Westphal
H. Whitelaw
Wilcox
Wygnanski
Stanford University Stanford, CA 94305 Dept. o," Mech. Eng. ImperlaL College Prince Consort Road London SW7 2BY, ENGLAND DCW Industries 4367 Troost Avenue Studio City, CA 91604 School of Engineering
Aide;
Tech,
Rec.
Data Taker
Computor
Rev.
Comm.
Tel-Aviv University Ramat Aviv, ISRAEL B.27
Dr.
Eisho Yamazato
Mechanical Eng. Dept. University of Ryukyus
Tonokura-cho, Okinawa, Dr.
K.
Mr.
Paul Youssefmir
T.
Yen
Naha
JAPAN
Department of the Navy Naval Air Developoent Center
Warminster. A.46
Data Taker
PA
Mech.
Computor
.
18974
Eng. Department Stanford University Stanford, CA 94305
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LIST OF DATA EVALUATORS
-•$
"Name
Flow No.
M. Acharya
0150
2-dimensional channel flow with periodic
S. Birch
0310
Planar mixing layer
0210
Effect of free-stream turbulence on boundary layers
0330
Free shear layer with streamwise
8500
Compressibility effects on free-shear layers
0410
Evaluation of bluff-body,
8670
Pointed axisymmetric bodies at angle of attack (supersonic)
P.
Bradshaw
"B.Cantwell Cockrell
D.J.
Coles
0610
Attached boundary layers -
R.B.
Dean
0510
Turbulcnt secondary
0470
Flow over the trailing
Drescher
J.K.
perturbations
178 170
D.E.
P.
Page
Flow Category
130
curvaure
near-wake
364
flows
220 543
Conference)
('68
flows of the
first
86
82
kind
139
edge of blades and airfoils
555
0420
Backward-facing
Favre
8680
Axisymmetric near wake flow (supersonic)
482
Ferziger
0370
Homogeneous
405
F.B. Gessner
0110
Corner
S. Honami
0230
Boundary layer flows with streamwise curvature
C.C. Horstman
8100
Supersonic flow over a flat plate (insulated wall)
369
8200
Supersonic
369
8400
Boundary layers in an adverse pressure gradient axisymmetric internal flow
in an
8410
Boundary layers in an adverse pressure gradient two-dimensional flow
in
A. J.H.
Eaton
step flow
275
turbulent flows
flow (secondary
flow of the second kind)
flow over a flat
plate
182 94
(cooled wall)
378 378
8600
Impinged normal shock wave-boundary at transonic speeds
layer i.nteraction
8610
Transoiic flow over a bump
458
8630
Compressible
458
8640
Compressible flow over compression corner with reartaching planar shear layer
458
8650
Axisymmetric shock impingement
486
8660
Three-dimen~sional shock impingement (supersonic)
486
8690
Nonlifting,
486
486
flow over deflected surfaces
transonic airfoil
(supersonic)
with shock separation
D.A.
Humphreys
0250
Three-dimensional
J.P.
Johnston
0420
Backward-facing step flow
275
Jones
0130
Entry zone of round tube
213
LUunder
0260
Turbulent wall jet
434
Melnik
8620
Transo
523
Horse
0340
Flows with swirl
J.B. B.E. R.E. A.P.
ic
turbulent boundary
airfoils
layers
162
317
622
Name
Flow No.
V.C. Patel
0350
Ship wakes
552
"0360 "0380 "0390
Wakes of round bodies
327
Wakes of two-dimensional bodies
340
AxisymmetrLc boundary layer with strong streamwise and transverse curvature
327
Pointed axisymmetric (supersonic)
543
D. Peake E.
8670
Reshotko W. Rodi
M.W.
Rubesin
L.
L.C.
Turbulent wall jet
8100
Supersonic
flow over a flat
plate (insulated wall)
369
"8200
Supersonic
flow over a flat
plate (cooled wall)
369
8400
Boundary layers in an adverse pressure axisymmetric t.nternal flow
434,
gradient
an 378
Boundary layers In an adverse pressure gradient two-dimensional flow Impinged normal shock wave-boundary at transonic speeds
in in
378
layer interaction 486
8610
Transonic
flow over a bump
458
"8630
Compressible flow over deflected
8640
Compressible flow over compression corner reattaching planar shear layer
surfaces
458 i tith 458
"8650 "8660 "8690
Axisymmetric shock impingement
Simon
0230
Boundary layer
flows with streamwise curvature
Simpson
0140
Diffuser flows
(unseparated)
"0430
Diffuser flows (separated)
253
0240
Turbulent
112
"8300
Turbulent boundary layers with suction or blowing at supersonic speeds
Squire
Sreenivasan
B. van den Berg
Three-dimensional Nonlifting,
(supersonic)
shock impingement
transonic
(supersonic)
with shock separation
airfoil
Variation in Number
486 486 94
-
i12
Cf/Cfo for blowing/suction with Mach 549
567
flows
0280
Relaminarizing
0250
Three-dimensional
turbulent boundary layers
Two-dimensional
J.C. Wyngaard
9000
Flows with bu,.:. cy forces
314
623
--
-.-
-.
---
-
162 234
stalled airfoil
0440
fI
486
253
boundary layers with suction or blowing
Wadcock
A.J.
554
transition
Laminar-turbulent
8310
K.R.
bodies at angle of attack
0260
8600
R.
Page
0290
8410
T.W.
Flow Category
-----
-
-
s--
-
-
-
-
j
NUMERICAL INDEX TO FLOW CASES AND DATA LIBRARY TAPE Nomenclature: Incompressible Flow C•mpressible Flow
0 8
Prefix
Flow number
0 or 8
Two digits
1..
{
0
2 Case number
'
3
0
} 8 Two
or
digits
4 5 6___I
Flow Category
(Evaluator)
(Flow
No.) Index to the Tape
No.
No. of
File
Files
Number
Page
28
2-29
182
Secondary currents in the turbulent flow through a straight conduit
4
30-33
182
Asymmetric
*
287
Entry zone of round tube
t
213
Entry zone of round tube
t
213
Data Taker
Title Incompressible
(F.
Gessner)
Flows
Corner flow (secondary (0110)
flow of the second kind) 0111 0112
J. F.
Po!E. LUnd; Gessner
J.
Hinze
0113
Developing flow in
--
(J.B.
0131
A. Barbin/J.
0132
D. Miller
I 0141
(R.L.
Jones)
Jones
Simpson)
a square duct
flow in
a square duct
Entry zone of round tube
Diffuser
flows
(0130)
(unsepat.)
(0140)
A. P.
S muel/ Joubert
Increasingly adverse pressure gradient flow
0142
R.
Pozzorini
0143
R. Pozzorini
Six-degeee conical diffuser low-core turb. Six-degree conical diffuser high-core turb.
.Predictive
Case P1.
%Not ubtd for
30
34-63
254
39
64-102
254
39
64-102
254
flow, flow,
1981 Conference. 624 -A
•o
-
-
.
.--
..-
--
-
.
Flow Category
(Evaluator)
Case No.
(Flow No.) Index to the Tape No. of File Files Number
Title
Data Taker
Page
Incompressible Flows (cont.)
I 0151 0152
A. W. M. W.
(M. Acharya)
Two-dimensional channel flow wittl periodic perturbations (0150)I
Perturbation wave in turbulent t shear flow Fully developed turbulent channel flow with imposed controlled oscillations t
Hussain/ Reynolds Acharya/ Reynolds
(P. Bradshaw) P. P.
Hancock/ Bradihaw
0231 0232 0233 0234 0235
2
103-104
86
Boundary layer flows with ( (0230) streamwyse curvature
Turbulent boundary layers on surfaces of 26 mild longitudinal curvature (convex) Turbulent boundary layers on surfaces of 26 mild longitudinal curvature (concave)
105-130
95
105-130
95
J. Gillis/ J. Johnston
Tuihulent boundary layer on a convex, curreA surface
26
131-156
95
I. Hunt/ P. Joubert
Effect!s of small streamline curvature 17t on i .bulent duct flow
157-173
96
A. Smits/S. Young/ P. Bradshaw
The effects of short regions of high surface curvature on turbulent bound~iry layers (convex 30 deg.)
P. P. P. P.
Hoffmann/ Bradshaw Hoffman/ Bradshaw
(L.C. Squire)
. 1 7t
174-190
96
Turbulent boundary layers (0240) with suction or blowing
Zero pressure gradient, constant injection
Il
191-201
114
-
0242
P. Andersen/ W. Kays/R. Noffat
Adverse pressure gradient with constant suction
13
202-214
114
p
0244
A. Favre et al.
Zero pressure gradient with constant (high) suction
11
215-225
114
tNot used for 1981
P
Conference. 625
-i.
-
.1
P. Andersen/ W. Kays/R. Moffat
0241
-
j
(0210)
Effect of free-stream turbulence
(T.W. Simon/ S. Honam!
179
Effect of free-streatn turbu-I lence on boundary layers
0211
178
.,:.*.
.
•..
-.
-
A
(Evaluator)
Flow Category
(Flow
No.)] Index to the Tape
Case No.
Data Taker
No. of Files
Title Incompreisible Flows
(D.A. Humphreys/ B. van den Berg)
File Number
Page
(cont.)
Three-dimensional turbulent boundary layers
(0250)
0251
B. van den Berg/ A. Elsenaav
NLR infinite swept wing experiment
2
0t
226-245
164
0252
L.
Part-rotating cylinder experiment
22t
246-267
164
0253
R1. Dechow
26t
268-293
164
0254
Lohmann,
23
294-316
164
7-333
435
Bissonnette
Cylinder R.
(B.E.
on a flat
test plate
Part-rotating cylinder
Launder/ W. Kodl)
Turbulent Wall Jet
(0260)
0261
Various
Turbulent wall jet data (equilibrium wall jet)
0262
E. Alcaraz; G. Fekete
Turbulent wall jet data (2-dLmensional, on a cyli
0263
D. B.
Turbulent wall jet data (self-preservirg on log-spiral)
17
317-333
438
0264
Various
Turbulent wall jet data (3-dimensional on plane surface)
17
317-333
439
Guitton/ Newman
(K. Sreenivasan)
Relaminarizing flows
17 'sr)
,
437
(0280)
0281
R. Simpson/ D. Wallace
Relaminarizing boundary layer
*
567
0282
J.
Relaminarizing tube flow
*
568
Laufer
(S. 0311
Various
Birch)
Planar mixing layer
(0310)
Planar mixing layer developing from turbulent wall bo,,ndary layers
6
334-339
tNot used for 1981 Conference" This case is not on data tape fot Library 1; it will appear on future revisions. 626
170
Flow C.ategory
(Evaluator)
Case No.
(Flow
No.) Index to the Tape No. of File Fi ei• Number
Title
Data Taker
Page
Incompressible Flows (cont.)
(P.
033i
I. P.
Bradshaw)
Castro/ Bradshaw
R.
Ferz1ger)
G. Comte-Bellot/
0372
S. Corrain R. Wigeland/ H. Nagib
Isotropic
130
72
376-447
327
19
448-466
406
turbulent (0370)j
turbulence
406
M. Uberoi; H. Tucker/A. Reynolds A. Townsend; H.
Return
406
Tucker/A.
Plane strain
406
Axisymmetric strain
407
Sherred turbulence
407
Reynolds
J.
0376
F.Champagne et al.; V. Harris et al.
Tan-atichat
(V.C.
0382
340-375
Rotating turbulence
0375
0381
Homogeneous flows
36
(0360)
The turbulent wake of a body of revolution
0371
0374
Wakes of round bodies
Patel)
Chevray
(J.H.
0373
(0330)
The turbulence structure of a highly curved mixing layer
(V.C.
0361
Free shear layer with streamwise curvature
J.
J.
Patel)
Andreopoulos
to isotropy
bodiWakes of
two-dimensional
(0380)
Measurements of interacting turbulent shear layers in the near wake of an airfoil (symmetric)
Andreopoulos
.1
52
467-518
346
Measurements of interacting turbulent shear layers in the near wake of an airfoil (asymmetric)
350
627
'*
I-L
••
..
.
.
•.
-
-.
,
.
.
-
.
-
.
-:
V..
L
(Evaluator)
Flow Category
(Flow
No.)
i Index to the Tape._
Case Title
Data Taker
No.
Incompressible (B.
0412
0421
.(J.K. EvLon/ J.P. Johnston)
(0410)
flowG
Backward-f.icing flow
Flow over a backward-facing
J. Kim/S. Kline/ J. Johnston
0422
Backward-facing passage
519-537
221 ,
223
+
-1 (0420)
32
step
step;
Backward-facing step; ratio
0424
..
step
Backward-facing step; opposite wall angle
0423
Page
Flows (cont.)
Phase-averaged large-scale structures in 3-dimensional wakes
Perry/ Watmuff
[I
Number
A flying hot-wire study of the turbulent near-wake of a circular cylinder 19 at a Reynolds number of 140,000
B. Cantwell/ D. Coles A. j.
File
Files
Evaluation of bluff-body,
Cartwell)
near-wake 0411
No. of
538-569
275
Xl
variable turned
*
297
4
301
#
304
flow
" I
variable area
__J
(R.L. 0431
R.
Simpson)
Simpson et al.
(A.J.
0441
A. Wadcock/ D. Coles
Diffuser flows (sep.)
(0430)
Separating adverse pressure gradient flow
Wadcock
Two-dimensional airfoil
36
570-605
255
4
606-609
234
stalled (0440)
Flying hot-wire study of 2-dimensional turbulent separation of an NACA 4412 at maximum lift airfoil
tNot used for 1981 Conference. •cedictive
Case P2.
Fredi
*Predictive Case F3.
Zi. ase
i4..
628
0
(Evaluator)
Case No.
Flow Category
Data Taker
(Flow
No.) Index to the Tape No. uf File Files Number
Title Incompressible Flows (cont.)
L]
(P.
0471
Drescher)
P. Viswanath et al.
Flow over the trailing of blades and airfoils
edge (0470)
Dean)
Turbulent
secondary
0512
I. J.
Humphrey
(D.E.
0612
Turbulent flow in bodv Junction
Shabaka
K. Wieghardt
Attached boundary layers (1968 Conference)
135
658-792
140
21
793-813
141
25
814-838
82
(0610)
On the turbulent friction layer
Correlation:
Various
insulated
Rubesin/
Cf/Cfo plate
Supersonic
C.C. Horstman)
.
i
versus M-369
flow over a flat
plate (cooled wall)
Correlation:
Various
Flows
Supersonic flow over a flat (8100) ] plate (insulated wall)
Rubesin/ (M.W. C.C. Horstman)
8201
(8200)
Cf/Cfo versus Tw/Taw
-- constant M
(L.C.
8301
Squire)
G. Thomas
Single curve---not
369
Turbulert boundary layers with suction or blowing at supersonic speeds (8300)
Favorable pressure gradient at supersonic speeds with injection
shown on data tape.
629
ii'i - , -'. "
" '. "
.-- - -" • .
555
an idealized wing-
Compressible
(M.W.
610-657
-
for rising pressure
8101
. 48
(0510)
Turbulent flow in a curved duct of squarp rrng-section
Coles)
.
flo.0
of the first kind 0511
1H
Trailing edge flows at high Reynolds number
(R.B.
Page
.
"
',
7, '
.
,"-. '
.... . "-..
-"
.
..
_
3
839-841
115
(Evaluator)
Flow Category
(Flow
No.) Index to the Tape
Case No.
No. of Data Taker Compressible
I I
(M.W. .C.
Rubesin/ Hoostman/
G.M. 8401 8402 8403
D. J.
Lewis et al.
M. Kussoy
* 8411
F.
Zwarta
8602
Boundary gradient
layer in
Koci
flow
378
9+
846-854
379
47
855-901
380, 388
8
902-909
381, 390
2
910-911
364
31
912-942
487
943-1061
487
(8400)
adverse pressure 4t adverse
pressure
+
Pressure gradient atd Reynolds number effects on compressible turbulent boundary layers in supersonic flow
Boundary layers in an adverse pressure gradient in two-dimensional flow (8410)
Bradshaw)
adverse
Compressibility effects on free-shear layers (8500)
Compressibility effects on freeshear layers
G. Mateer et al. J.
int'nal
layer in
(M.W. Rubesin/ C.C. Horstman)
8601
symmetric
Boundary layer in pressure gradient
Various
842-845
Flows (cont.)
Boundary gradient
(H.W. Rubesin/ C.C. Horstman/ G.M. Lilley)
(P.
8501
et ai.
Page
Boundary layers in an adverse pressure gradient in an axi-
Lilley)
Peake et al.
File Number
riles
Title
Impinged normal shock waveboundary layer interaction at transonic speeds (8600)
I
Normal shock wave/turbulent boundarylayer interaction at tranronic speeds Influence of
free-stream Mach number shock wave-boundary interaction
"on traaaonic layer
"Not used for 1981 Conference. 630
119t
(Evaluator)
Case No.
Flow Category
(Flow
Data Taker
(M.W. Rubesin/ C.C. Horstman)
8612
8623
8632
(8610)
1062-1075
459
J. P.
Transonic bump, M -
44
1076-1119
459
Aerofoil RAE 2822--pressure distribution, 74 boundary layer and wake measurements
1120-1193
524
Supercritical measurements
18
1194-1241
526
Attached and separated comFression corner flow fields in high Reynolds number supersonic flow
50
1242-1291
459
Turbulent boundary-layer/expansion interaction at supersonic speed
32
1292-1323
460
13
1324-1336
460
34
1337-1370
486
Delery/ Le Diuzet
P. F. L.
Melnik)
Cook et al. Spaid/ Stivers
G. Settles et al.
J. J.
Dussauge/ Gaviglio
Rubesin/ Horstman
G. Settles et al.
f 8651
flow over a
14
(M.W. C.C.
8641
(cont.)
Transonic turbulent boundary layer separation on an axisymmnetric buwp
(M.W. Rubesin/ C.C. Horstman) 8631
Transonic bump
Page
W. Bachalo/ D. Johnson
(R.E. 8621
Index to the Tape No. of File Files Number
Title Compressible Flows
8611
No.)
Transonic airfoils
(8620)
airfoil
boundary layer
Compressible flow over deflected surfaces
(8630)
i
Compressible flow over compression corner with reattaching planar shear layer (8640)
Reattaching planar free-shear layer (superscaiz)
(M.W. Rubesin/ C.C. Horstman)
M. Kussoy/ C. Horstman
flow over two-dimensional 1.37
Axisymmetric shock impingement (oupersonic)
1 (8650)
Hypersonic shock wave turbulent boundary-layer interaction-- with and without reparation
631
-
-
-
*
.~
-...
%¶
[
(Evaluagor)
Flow Category
........ (Flow
No.)•
Index
Case
No.
No.
Data Taker
Title Coi,•presslble
to the Tape
of
,
File
Files
Number
"i• Page
Flows (cont.)
i-
--
--
;• " :-' •" ==v .
(M.W C C. '
8661
D.
Rubesin/ |ior.•tman)
S8663
I
Three-dlmensional 9hock impingement (supecsonlc)
(8660)[ °
Peake
Three-dimensional swept ahock/turbulent boundary layer interaction
-,
f,.',
M. Kussoy et al. Investlgatton of three-dimensional shock •eparated turbulent boundary layer 47 S(D.J. Peake/ Pointed a×isymraetrlc bodies .at
DJ.
l
,
486
1378-1424
486
1425-1454
543
•_-"-'•
!1
angle of atlack
•ockrell)
1371-1377
(supersonic)
(8670)
i
I 8671
W.
Ralnblrd
Pointed
angle
] [ 8691
(M.W. Rubesin! C.C. Horstman)
J. McDevltt al.
et
axlsymmetri¢
of attack
bodies
at
(supersonic)
30
Nonllfting, transonic airfoil l with shock separation (8690), i
Non-liftlng transonic airfoil, shock-separated flow
:"I •-•
13
1455-1467
487
,•.# i • -'ql
-...•
!•f.i..
. '--
•
...
;•%° -. °,."
-°
-.
•illl il •.
,
•
-!
•-':-•"
--,. • .
632
- ,,.•.. .>'-il.i- 2.-.:..>v ..- '• .. i•.
. •
-
"
. " . •, i'. "
"
.•
