Turbulent boundary layers were subjected to grid-generated free-stream turbulence to study the effects of length scale and intensity on heat transfer. Relative to conventional boundary layer thickness measures, test conditions included very small-scale free-stream turbulence. The boundary layers studied ranged from 400–2700 in momentum-thickness Reynolds number and from 450–1900 in enthalpy-thickness Reynolds number. Free-stream turbulence intensities varied from 0.1–8.0%. Ratios of free-stream length scale to boundary-layer momentum thickness ranged from 4.4–32.5. The turbulent-to-viscous length-scale ratios presented are the smallest found in the heat-transfer literature; the ratios spanned from 115–1020. The turbulent-to-thermal ratios (using enthalpy thickness as the thermal scale) are also the smallest reported; the ratios ranged from 3.2–12.3. Relative to clean-free-stream expectations based on the momentum- and enthalpy-thickness Reynolds numbers, the skin friction coefficient increased by up to 16%, and the Stanton number increased by up to 46%.

1.
Anwer, M. N., 1985, “Design, Construction, and Testing of a Two-Stream Mixing Layer Wind Tunnel Facility,” M.S. thesis, Dept. of Mech. Eng., University of Houston.
2.
Belbas, C. A., 1993, “Design and Qualification of a Heat Transfer Surface for Studies of High Turbulence,” M.S. thesis, Dept. of Mech. Eng., University of Houston.
3.
Roach
,
P. E.
,
1987
, “
The Generation of Nearly Isotropic Turbulence by Means of Grids
,”
Int. J. Heat Fluid Flow
,
8
(
2
), pp.
82
92
.
4.
Johnson, P. L., and Johnston, J. P., 1989, “The Effects of Grid-Generated Turbulence on Flat and Concave Turbulent Boundary Layers,” Report No. MD-53, Dept. of Mech. Eng., Stanford University.
5.
Townsend, A. A., 1976, The Structure of Turbulent Shear Flow, Cambridge University Press.
6.
Browne
,
L. W. B.
,
Antonia
,
R. A.
, and
Chua
,
L. P.
,
1989
, “
Calibration of x-Probe for Turbulent Flow Measurements
,”
Exp. Fluids
,
7
, pp.
201
208
.
7.
Maniam, B. M., 1997, “An Experimental Study of the Turbulent Momentum and Thermal Boundary Layers Beneath a Two-Stream Mixing Layer,” Ph.D. dissertation, Dept. of Mech. Eng., University of Houston.
8.
Spalart
,
P. R.
,
1988
, “
Direct Simulation of a Turbulent Boundary Layer up to Rθ=1410,
J. Fluid Mech.
,
187
, pp.
61
98
.
9.
Fernholz
,
H. H.
, and
Finley
,
P. J.
,
1996
, “
The Incompressible Zero-Pressure-Gradient Turbulent Boundary Layer: An Assessment of the Data
,”
Prog. Aerosp. Sci.
,
32
, pp.
245
311
.
10.
Thole
,
K. A.
, and
Bogard
,
D. G.
,
1996
, “
High Freestream Turbulence Effects on Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
,
118
, pp.
276
284
.
11.
Barrett
,
M. J.
, and
Hollingsworth
,
D. K.
,
2001
, “
On the Calculation of Length Scales for Turbulent Heat Transfer Correlation
,”
ASME J. Heat Transfer
,
123
, pp.
878
883
.
12.
Kays, W. M., and Crawford, M. E., 1980, Convective Heat Transfer, 2nd Edition, Mc-Graw Hill.
13.
Maniam, B. M., and Hollingsworth, D. K., 1998, “Experimental Investigation of Heat Transfer in a Three-Dimensional Boundary Layer Beneath a Mixing Layer,” Proc., 7th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, Albuquerque, NM, 2, pp. 123–130.
14.
Thole
,
K. A.
, and
Bogard
,
D. G.
,
1995
, “
Enhanced Heat Transfer and Shear Stress Due to High Free-Stream Turbulence
,”
ASME J. Turbomach.
,
117
, pp.
418
424
.
15.
Ames, F. E., and Moffat, R. J., 1990, “Heat Transfer with High Intensity, Large Scale Turbulence: The Flat Plate Turbulent Boundary Layer and the Cylindrical Stagnation Point,” Report No. HMT-44, Dept. of Mech. Eng., Stanford University.
16.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single Sample Experiments
,”
Mech. Eng. (Am. Soc. Mech. Eng.)
,
75
, pp.
3
8
.
17.
Halstead
,
D. E.
,
Wisler
,
D. C.
,
Okiishi
,
T. H.
,
Walker
,
G. J.
,
Hodson
,
H. P.
, and
Shin
,
H.-W.
,
1997
, “
Boundary Layer Development in Axial Compressors and Turbines: Part 3 of 4—LP Turbines
,”
ASME J. Turbomach.
,
119
, pp.
225
237
.
18.
Bradshaw, P., and Huang, G. P., 1995, “The Law of the Wall in Turbulent Flow,” Proc., Royal Society of London A, 451, pp. 165–188.
19.
Maciejewski, P. K., and Moffat, R. J., 1989, “Heat Transfer with Very High Free-Stream Turbulence,” Report No. HMT-42, Dept. of Mech. Eng., Stanford University.
1.
Maciejewski
,
P. K.
, and
Moffat
,
R. J.
,
1992
, “
Heat Transfer with Very High Free-Stream Turbulence
,”
ASME J. Heat Transfer
, Part I-Experimental data.
114
,
827
833
;
2.
Part II-Analysis of results,
114
,
834
839
.
1.
Barrett, M. J., 1998, “Skin Friction and Heat Transfer in Turbulent Boundary Layers Subjected to Small-Scale Free-Stream Turbulence,” Ph.D. dissertation, Dept. of Mech. Eng., University of Houston.
2.
Hancock
,
P. E.
, and
Bradshaw
,
P.
,
1983
, “
The Effect of Free-Stream Turbulence on Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
,
105
, pp.
284
289
.
3.
Sahm, M. K., and Moffat, R. J., 1992, “Turbulent Boundary Layers with High Turbulence: Experimental Heat Transfer and Structure on Flat and Convex Walls,” Report No. HMT-45, Dept. of Mech. Eng., Stanford University.
4.
Ames, F. E., and Plesniak, M. W., 1995, “The Influence of Large Scale, High Intensity Turbulence on Vane Aerodynamic Losses, Wake Growth, and the Exit Turbulence Parameters,” Proc., International Gas Turbine and Aeroengine Congress and Exposition, Houston, TX, ASME Paper 95-GT-290.
5.
Thole, K. A., 1992, “High Free-Stream Turbulence Effects on the Transport of Heat and Momentum,” Ph.D. dissertation, The University of Texas at Austin.
6.
Bott, D. M., and Bradshaw, P., 1997, “Effect of High Levels of Free-Stream Turbulence on Boundary Layer Skin Friction and Heat Transfer,” Report No. MD-75, Dept. of Mech. Eng., Stanford University.
7.
Bott, D. M., and Bradshaw, P., 1998, “Effect of High Free-Stream Turbulence on Boundary Layer Skin Friction and Heat Transfer,” Proc., 36th Aerospace Sciences Meeting & Exhibit, Reno, NV, AIAA Paper 98-0531.
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