尾迹对涡轮动叶全表面气膜冷却效率的影响

The effect of unsteady wake on the film cooling effectiveness of the turbine blade is studied using the Pressure Sensitive Paint (PSP) measurement technique. The test blade has eleven rows of cylindrical film holes. The distribution of the film cooling effectiveness on the whole blade surface under different mass flux ratios and different wake Strouhal numbers (Sr=0, 0.12, 0.36) are obtained. The results show that as the wake Strouhal number increases, the radial averaged film cooling effectiveness of the leading edge decreases by up to 36.5%, the radial averaged film cooling effectiveness of the suction surface decreases by up to 53.5%, and that of the pressure surface decreases by up to 24.2%. The effect of wake on the leading edge and the suction surface is greater than that on the pressure surface. As the mass flux ratio increases, the effect of the unsteady wake decreases. When designing the cooling structure of the turbine blade, ignoring the effect of the wake increases the design risk.