尾迹影响下有复合角扇形孔涡轮叶片表面的气膜冷却效率实验研究

The film cooling effectiveness of the turbine blade with compound-angled fan-shaped holes was measured by the pressure sensitive paint technique. The wake's Strouhal number was varied from 0 to 0.36 and three mass flux ratios were determined. Results show that the compound-angled holes can enhance the lateral spreading of coolant, and the injection has a wider coverage area without wakes. The increase of the mass flux ratio causes an increase in the film cooling effectiveness over the leading edge and most area of the pressure surface with compound-angled holes, but a decrease on the suction surface. The increase of mass flux ratio also reduces the area near the tip on the suction side, where the film coverage is insufficient under wake influence, and causes an increase in the film cooling effectiveness over the leading edge, the pressure surface and the suction surface near the trailing edge, but decreases this effectiveness on the mid-chord region of the suction surface. The wake causes a remarkable decrease in the film cooling effectiveness over the blade surface. In the case that wake's Strouhal number is 0.36, the average film cooling effectiveness over the blade is decreased by 35% under the condition of low mass flux ratio, and decreased by 26% under the condition of high mass flux ratio.