尾迹对动叶表面簸箕孔气膜冷却影响实验

Test on effect of wake on film cooling for turbine blade with dust-pan shaped holes

采用压敏漆(PSP)技术研究了上游尾迹对吸力面和压力面带有单排簸箕形气膜孔的涡轮动叶表面气膜冷却效率的影响,获得了不同吹风比(0.25～1.5)和尾迹斯特劳哈尔数(0、0.12、0.36)条件下涡轮叶片表面气膜冷却效率分布的实验数据,结果表明:尾迹使吸力面簸箕孔后径向平均气膜冷却效率最大下降幅度达0.07,使压力面簸箕孔后径向平均气膜冷却效率最大下降幅度达0.024;有尾迹时,随着吹风比的增加,吸力面气膜孔后冷却效率逐渐降低,压力面气膜孔后冷却效率先增加后降低。

The effect of unsteady wake on the film cooling effectiveness of the turbine blade was studied using the pressure sensitive paint(PSP)measurement technique.The test blade had two rows of dust-pan shaped film holes on the suction surface and the pressure surface,respectively.The blowing ratio varied from 0.25 to 1.5 and the wake Strouhal number of 0,0.12,0.36.Results showed that as the wake Strouhal number increased,the spanwise averaged film cooling effectiveness of the suction surface decreased by up to 0.07 and the span-wise averaged film cooling effectiveness of the pressure surface decreased by up to 0.024.For the wake cases,an increase in the blowing ratio caused a decrease in film cooling effectiveness on the suction surface.The film cooling effectiveness increased first and then decreased on the pressure surface as the blowing ratio increased.