Abstract: The effects of unsteady wake on the leading edge film cooling effectiveness of the turbine blade were studied using the Pressure Sensitive Paint (PSP) measurement technique. The test blade has three rows of compound angled cylindrical film holes on the leading edge. The blowing ratio is varied from 1.0 to 3.0 and the wake Strouhal number is varied from 0 to 0.36. Results show that for the wake cases， an increase in the blowing ratio causes an increase in film cooling effectiveness over most of the blade surface except the pressure side next to the film holes. As the wake Strouhal number increases， the span-wise averaged film cooling effectiveness of the pressure side increases by up to 0.07， the span-wise averaged film cooling effectiveness of the leading edge decreases by up to 0.13 and that of the suction side decreases by up to 0.18. Overall， the wake causes a decrease in the film cooling effectiveness on most region of the leading edge on the turbine blade.

Key words: Wake；Film cooling effectiveness；Leading edge；Pressure sensitive paint；Strouhal number；Turbine blade

摘要： 为探究上游尾迹影响下的涡轮动叶前缘气膜冷却特性，采用压力敏感漆技术，研究了尾迹对涡轮动叶前缘带有三排径向复合角圆柱形气膜孔的气膜冷却效率的影响，获得了不同吹风比(1.0 ～ 3.0)和尾迹斯特劳哈尔数(0，0.12，0.36)条件下前缘区域全表面气膜冷却效率分布的实验数据。结果表明:有尾迹时，随着吹风比的增加，叶片前缘大部分区域气膜冷却效率逐渐增加，仅有压力面侧气膜孔附近冷却效率逐渐降低。随着尾迹斯特劳哈尔数增加，前缘靠近压力面侧孔排下游的径向平均气膜冷却效率最大增加幅度达0.07，前缘正中间孔排附近径向平均气膜冷却效率最大降低幅度达0.13，前缘靠近吸力面侧孔排下游的径向平均气膜冷却效率最大降低幅度达0.18。整体看来，尾迹使前缘大部分区域气膜冷却效率降低。

关键词: 尾迹；气膜冷却效率；前缘；压力敏感漆；斯特劳哈尔数；涡轮动叶