涡轮动叶压/吸力面气膜孔冷却特性实验研究

Experimental Study of Film Cooling Characteristics on Pressure and Suction Side in a Turbine Blade

关键词:  涡轮动叶  吸力面  压力面  气膜冷却  雷诺数  马赫数

Key words:  Turbine blade  Suction side  Pressure side  Film Cooling  Reynolds number  Mach number

摘要:

为了研究涡轮动叶的气膜冷却特性，在短周期跨声速换热风洞中测量了静止条件下压力面和吸力面气膜孔的冷却效率，分析了主流雷诺数、马赫数和吹风比对气膜孔冷却效率分布的影响规律。实验结果表明:无论压力面孔和吸力面孔，整体冷却效率均随着吹风比的增大而降低；压力面孔在高雷诺数工况下的冷却效率要更高，而吸力面孔在2.0的大吹风比工况时，低雷诺数下的冷却效率在近孔区域(30倍孔径距离内)高于高雷诺数工况。改变马赫数对压力面冷却效率几乎无影响，而在Ma=0.913工况下，在吸力面孔后28倍孔径位置处冷却效率突然降低至0.05以下。

Abstract:

In order to investigate the film cooling characteristics of a turbine blade，the film cooling effectiveness on pressure side and suction side was measured in the short-duration transonic heat transfer wind tunnel at stationary condition，and the effects of mainstream Reynolds number，Mach number and blowing ratio on the distribution of film cooling effectiveness were analyzed. The experimental results indicate that，the overall effectiveness decreases with the blowing ratio increasing for both on pressure side and suction side. For the hole on pressure side，the effectiveness is higher at a higher Reynolds number case. When the blowing ratio is as high as 2.0 on suction side，the effectiveness of high Reynolds number cases is higher than low Reynolds number cases at the region near the hole (30 diameters). Changing Mach number has neglectable effects on effectiveness of pressure side. However，at the case of Ma=0.913 on suction side，the effectiveness decreases to 0.05 or lower abruptly at the position of 28 diameters.