Heat transfer measurements have been made in the stagnation region of a flat plate with an elliptical leading edge. The radius of curvature at the stagnation point was similar to that of a first stage turbine vane airfoil used in a large commercial high-bypass turbofan engine. The airfoil was mounted downstream of an arc segment of a dual-annular combustor similar to the type used in an advanced turbine engine. Testing was done in air at atmospheric temperature and at pressures up to 376 kPa to simulate the vane leading edge Reynolds number seen in the engine. Spanwise average stagnation region heat transfer was measured with an electrically heated aluminum strip. Turbulence intensity, length scale and isotropy were measured using standard 2-wire hot wire probes. The combustor contained two annular rows of fuel-air swirlers which were aligned in the radial direction. Both heat transfer and hot wire data were taken at two circumferential positions; one directly downstream of a pair of swirlers and one half way between two pairs of swirlers. Reynolds number based on vane leading edge diameter was varied from 51000 to 160000. The maximum Reynolds number for turbulence measurements was limited to 87000. Turbulence intensity averaged over all test conditions was found to be 31.6%. Average axial, integral length scale was 1.29 cm, which gave a length scale-to-leading edge diameter ratio of 1.08. The turbulence was found to be nearly isotropic with the average ratio of axial to circumferential fluctuating components of 1.15. Heat transfer augmentation above laminar levels was found to vary from 34 to almost 59% depending on the Reynolds number. No effect of circumferential position was found. The heat transfer augmentation was found to be well predicted by a correlation derived from grid generated turbulence.Copyright © 2002 by ASME
[1]
G. J. Van Fossen,et al.
Three-Dimensional Flow Field Measurements in a Transonic Turbine Cascade
,
1996
.
[2]
Ching-Pang Lee,et al.
Measurements of Combustor Velocity and Turbulence Profiles
,
1993
.
[3]
Arnold M. Kuethe,et al.
Effects of Turbulence on Laminar Skin Friction and Heat Transfer
,
1966
.
[4]
R. I. Vachon,et al.
The effect of turbulence on heat transfer from heated cylinders
,
1975
.
[5]
R. Simoneau,et al.
Influence of Turbulence Parameters, Reynolds Number, and Body Shape on Stagnation-Region Heat Transfer
,
1994
.
[6]
S. J. Kline,et al.
Describing Uncertainties in Single-Sample Experiments
,
1953
.
[7]
Forrest E. Ames,et al.
Experimental Study of Vane Heat Transfer and Aerodynamics at Elevated Levels of Turbulence
,
1994
.
[8]
William F. Kieffer.
Tables of thermal properties of gases
,
1956
.
[9]
S. Yavuzkurt.
A Guide to Uncertainty Analysis of Hot-Wire Data
,
1984
.
[10]
D. R. Zimmerman,et al.
Laser anemometer measurements at the exit of a T63 combustor
,
1979
.
[11]
G. J. Vanfossen,et al.
Increased heat transfer to elliptical leading edges due to spanwise variations in the freestream momentum: Numerical and experimental results
,
1992
.
[12]
J. C. R. Hunt,et al.
Free-stream turbulence near plane boundaries
,
1978,
Journal of Fluid Mechanics.
[13]
R. J. Simoneau,et al.
Heat transfer distributions around nominal ice accretion shapes formed on a cylinder in the NASA Lewis Icing Research Tunnel
,
1984
.