Slot film cooling in an accelerating boundary layer with high freestream turbulence is studied numerically using large eddy simulations (LES). Calculations are done for a symmetrical leading edge geometry with the slot fed by a plenum populated with pin fins. The synthetic eddy method is used to generate different levels of turbulence and length scales at the inflow cross-plane. Calculations are done for a Reynolds number of 250,000 and freestream turbulence levels of 0.7%, 3.5%, 7.8%, and 13.7% to predict both film cooling effectiveness and heat transfer coefficient over the test surface. These conditions correspond to the experimental measurements of (Busche, M. L., Kingery, J. E., and Ames, F. E., 2014, “Slot Film Cooling in an Accelerating Boundary Layer With High Free-Stream Turbulence,” ASME Paper No. GT2014-25360.) Numerical results show good agreement with measurements and show the observed decay of thermal effectiveness and increase of Stanton number with turbulence intensity. Velocity and turbulence exiting the slot are nonuniform laterally due to the presence of pin fins in the plenum feeding the slot which creates a nonuniform surface temperature distribution. No transition to fully turbulent boundary layer is observed throughout the numerical domain. However, freestream turbulence increases wall shear stress downstream driving the velocity profiles toward the turbulent profile and counteracts the laminarizing effects of the favorable pressure gradient. The effective Prandtl number decreases with freestream turbulence. The temperature profiles deviate from the self-similar profile measured under low freestream turbulence condition, reflecting the role of the increased diffusivity in the boundary layer at higher freestream turbulence.

References

1.
Bunker
,
R. S.
,
2011
, “
A Study of Mesh-Fed Slot Film Cooling
,”
ASME J. Turbomach.
,
133
(
1
), p.
011022
.
2.
Busche
,
M. L.
,
Kingery
,
J. E.
, and
Ames
,
F. E.
,
2014
, “Slot Film Cooling in an Accelerating Boundary Layer With High Free-Stream Turbulence,”
ASME
Paper No. GT2014-25360.
3.
Wieghardt
,
K.
,
1946
, “Hot-Air Discharge for De-Icing,” AAF Translation, Wright Field, OH, Report No. F-TS-919-RE.
4.
Hartnett
,
J. P.
,
Birkebak
,
R. C.
, and
Eckert
,
E. R. G.
,
1961
, “
Velocity Distributions, Temperature Distributions, Effectiveness and Heat Transfer for Air Injected Through a Tangential Slot Into a Turbulent Boundary Layer
,”
ASME J. Heat Transfer
,
83
(
3
), pp.
293
305
.
5.
Goldstein
,
R. J.
, and
Haji-Sheikh
,
A.
,
1967
, “
Prediction of Film Cooling Effectiveness
,”
JSME 1967 Semi-International Symposium
, Tokyo, Japan, Sept. 4–8, pp. 213–218.
6.
Seban
,
R. A.
,
1960
, “
Heat Transfer and Effectiveness for a Turbulent Boundary Layer With Tangential Fluid Injection
,”
ASME J. Heat Transfer
,
82
(
4
), pp.
303
312
.
7.
Spalding
,
D. B.
,
1965
, “
Prediction of Adiabatic Wall Temperatures in Film-Cooling Systems
,”
AIAA J.
,
3
(
5
), pp.
965
967
.
8.
Hartnett
,
J. P.
,
1985
, “
Mass Transfer Cooling
,”
Handbook of Heat Transfer Applications
,
W. M.
Rohsenow
,
J. P.
Hartnett
, and
E. N.
Ganic
, eds.,
McGraw-Hill
,
NewYork
.
9.
Goldstein
,
R. J.
,
1971
, “
Film Cooling
,”
Advances in Heat Transfer
, Vol. 7,
B. S.
Jone
and
R. Z.
Smith
, eds.,
Academic Press
,
New York
, pp.
321
379
.
10.
Acharya
,
S.
, and
Kanani
,
Y.
,
2017
, “
Advances in Film Cooling Heat Transfer
,”
Advances in Heat Transfer
, Vol. 49,
E. M.
Sparrow
,
J. P.
Abraham
, and
J. M.
Gorman
, eds.,
Academic Press
,
Cambridge, MA
, pp.
91
156
.
11.
Teekaram
,
A. J. H.
,
Forth
,
C. J. P.
, and
Jones
,
T. V.
,
1991
, “
Film Cooling in the Presence of Mainstream Pressure Gradients
,”
ASME J. Turbomach.
,
113
(
3
), pp.
484
492
.
12.
Carlson
,
L. W.
, and
Talmor
,
E.
,
1968
, “
Gaseous Film Cooling at Various Degrees of Hot-Gas Acceleration and Turbulence Levels
,”
Int. J. Heat Mass Transfer
,
11
(
11
), pp.
1695
1713
.
13.
Kacker
,
S. C.
, and
Whitelaw
,
J. H.
,
1968
, “
The Effect of Slot Height and Slot-Turbulence Intensity on the Effectiveness of the Uniform Density, Two-Dimensional Wall Jet
,”
ASME J. Heat Transfer
,
90
(
4
), pp.
469
475
.
14.
Kacker
,
S. C.
, and
Whitelaw
,
J. H.
,
1969
, “
An Experimental Investigation of the Influence of Slot-Lip-Thickness on the Impervious-Wall Effectiveness of the Uniform-Density, Two-Dimensional Wall Jet
,”
Int. J. Heat Mass Transfer
,
12
(
9
), pp.
1196
1201
.
15.
Kanani
,
Y.
, and
Acharya
,
S.
,
2016
, “
Numerical Investigation of Slot Film Cooling Over a Flat Plate—Part 2: Plenum Turbulence Effect
,”
HT/FE/ICNMM Conferences
, Washington DC, July 10–14.
16.
Simon
,
F. F.
,
1986
, “Jet Model for Slot Film Cooling With Effect of Free-Stream and Coolant Turbulence,” NASA Lewis Research Center, Washington, DC, Report No.
NASA-TP-2655
.https://ntrs.nasa.gov/search.jsp?R=19870008601
17.
Lebedev
,
V. P.
,
Lemanov
,
V. V.
,
Misyura
,
S. Y.
, and
Terekhov
,
V. I.
,
1995
, “
Effects of Flow Turbulence on Film Cooling Efficiency
,”
Int. J. Heat Mass Transfer
,
38
(
11
), pp.
2117
2125
.
18.
Jarrin
,
N.
,
Benhamadouche
,
S.
,
Laurence
,
D.
, and
Prosser
,
R.
,
2006
, “
A Synthetic-Eddy-Method for Generating Inflow Conditions for Large-Eddy Simulations
,”
Int. J. Heat Fluid Flow
,
27
(
4
), pp.
585
593
.
19.
Lilly
,
D. K.
,
1992
, “
A Proposed Modification of the Germano-Subgrid-Scale Closure Method
,”
Phys. Fluids a-Fluid Dyn.
,
4
(
3
), pp.
633
635
.
20.
Hunt
,
J. C. R.
,
Wray
,
A. A.
, and
Moin
,
P.
,
1988
, “
Eddies, Streams, and Convergence Zones in Turbulent Flows
,”
Summer Program Center for Turbulence Research
, Stanford University, Stanford, CA, pp.
193
208
.http://adsabs.harvard.edu/abs/1988stun.proc..193H
21.
Nagarajan
,
S.
,
Lele
,
S. K.
, and
Ferziger
,
J. H.
,
2007
, “
Leading-Edge Effects in Bypass Transition
,”
J. Fluid Mech.
,
572
, pp.
471
504
.
22.
Goldstein
,
M. E.
, and
Sescu
,
A.
,
2008
, “
Boundary-Layer Transition at High Free-Stream Disturbance Levels—Beyond Klebanoff Modes
,”
J. Fluid Mech.
,
613
, pp.
95
124
.
23.
Marusic
,
I.
,
McKeon
,
B. J.
,
Monkewitz
,
P. A.
,
Nagib
,
H. M.
,
Smits
,
A. J.
, and
Sreenivasan
,
K. R.
,
2010
, “
Wall-Bounded Turbulent Flows at High Reynolds Numbers: Recent Advances and Key Issues
,”
Phys. Fluids
,
22
(
6
), p. 065103.
24.
Piomelli
,
U.
,
Balaras
,
E.
, and
Pascarelli
,
A.
,
2000
, “
Turbulent Structures in Accelerating Boundary Layers
,”
J. Turbul.
,
1
, pp.
1
16
.
25.
Castillo
,
L.
, and
Wang
,
X.
,
2004
, “
Similarity Analysis for Nonequilibrium Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
,
126
(
5
), pp.
827
834
.
26.
Samson
,
A.
, and
Sarkar
,
S.
,
2015
, “
Effects of Free-Stream Turbulence on Transition of a Separated Boundary Layer Over the Leading-Edge of a Constant Thickness Airfoil
,”
ASME J. Fluids Eng.
,
138
(
2
), p.
021202
.
27.
Thole
,
K. A.
, and
Bogard
,
D. G.
,
1996
, “
High Freestream Turbulence Effects on Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
,
118
(
2
), pp.
276
284
.
28.
Stefes
,
B.
, and
Fernholz
,
H.-H.
,
2004
, “
Skin Friction and Turbulence Measurements in a Boundary Layer With Zero-Pressure-Gradient Under the Influence of High Intensity Free-Stream Turbulence
,”
Eur. J. Mech.-B/Fluids
,
23
(
2
), pp.
303
318
.
29.
Sunden
,
B.
,
1979
, “
A Theoretical Investigation of the Effect of Freestream Turbulence on Skin Friction and Heat Transfer for a Bluff Body
,”
Int. J. Heat Mass Transfer
,
22
(7), pp.
1125
1135
.
30.
Bons
,
J. P.
,
2002
, “
St and Cf Augmentation for Real Turbine Roughness With Elevated Freestream Turbulence
,”
ASME J. Turbomach.
,
124
(
4
), pp.
632
644
.
31.
Schlichting
,
H.
,
1979
,
Boundary-Layer Theory
,
McGraw-Hill
,
New York
.
32.
Ludwieg
,
H.
, and
Tillmann
,
W.
, 1950, “Investigation of the Wall-Shearing Stress in Turbulent Boundary Layers,” National Advisory Committee for Aeronautics, Washington, DC, Report No.
NACA-TM-1285
.https://ntrs.nasa.gov/search.jsp?R=19930093945
33.
Achenbach
,
E.
,
1968
, “
Distribution of Local Pressure and Skin Friction Around a Circular Cylinder in Cross-Flow Up to Re = 5 × 106
,”
J. Fluid Mech.
,
34
(
4
), pp.
625
639
.
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