TY - GEN
T1 - The effects of freestream turbulence, turbulence length scale and exit Reynolds number on turbine blade heat transfer in a transonic cascade
AU - Carullo, J. S.
AU - Nasir, S.
AU - Cress, R. D.
AU - Ng, W. F.
AU - Thole, K. A.
AU - Zhang, L. J.
AU - Moon, H. K.
PY - 2007
Y1 - 2007
N2 - This paper experimentally investigates the effect of high freestream turbulence intensity, turbulence length scale, and exit Reynolds number on the surface heat transfer distribution of a turbine blade at realistic engine Mach numbers. Passive turbulence grids were used to generate freestream turbulence levels of 2%, 12%, and 14% at the cascade inlet. The turbulence grids produced length scales normalized by the blade pitch of 0.02, 0.26, and 0.41, respectively. Surface heat transfer measurements were made at the midspan of the blade using thin film gauges. Experiments were performed at exit Mach numbers of 0.55, 0.78 and 1.03 which represent flow conditions below, near, and above nominal conditions. The exit Mach numbers tested correspond to exit Reynolds numbers of 6 × 105, 8 × 105, and 11 × 105, based on true chord. The experimental results showed that the high freestream turbulence augmented the heat transfer on both the pressure and suction sides of the blade as compared to the low freestream turbulence case. At nominal conditions, exit Mach 0.78, average heat transfer augmentations of 23% and 35% were observed on the pressure side and suction side of the blade, respectively.
AB - This paper experimentally investigates the effect of high freestream turbulence intensity, turbulence length scale, and exit Reynolds number on the surface heat transfer distribution of a turbine blade at realistic engine Mach numbers. Passive turbulence grids were used to generate freestream turbulence levels of 2%, 12%, and 14% at the cascade inlet. The turbulence grids produced length scales normalized by the blade pitch of 0.02, 0.26, and 0.41, respectively. Surface heat transfer measurements were made at the midspan of the blade using thin film gauges. Experiments were performed at exit Mach numbers of 0.55, 0.78 and 1.03 which represent flow conditions below, near, and above nominal conditions. The exit Mach numbers tested correspond to exit Reynolds numbers of 6 × 105, 8 × 105, and 11 × 105, based on true chord. The experimental results showed that the high freestream turbulence augmented the heat transfer on both the pressure and suction sides of the blade as compared to the low freestream turbulence case. At nominal conditions, exit Mach 0.78, average heat transfer augmentations of 23% and 35% were observed on the pressure side and suction side of the blade, respectively.
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U2 - 10.1115/GT2007-27859
DO - 10.1115/GT2007-27859
M3 - Conference contribution
AN - SCOPUS:34548803848
SN - 079184790X
SN - 9780791847909
T3 - Proceedings of the ASME Turbo Expo
SP - 1077
EP - 1089
BT - Proceedings of the ASME Turbo Expo 2007 - Power for Land, Sea, and Air
PB - American Society of Mechanical Engineers (ASME)
T2 - 2007 ASME Turbo Expo
Y2 - 14 May 2007 through 17 May 2007
ER -