离散气膜孔对涡轮端壁气膜冷却特性的影响

In this paper, the effects of mass flow ratio, density ratio and leakage flow on the film cooling characteristic of the turbine endwall with a discrete film hole layout were studied using the pressure sensitive paint (PSP) technology. The results show that the mass flow ratio of the discrete film holes (R_mf1) has a great influence on the distribution of film cooling effectiveness in the upstream region of the endwall, especially the area near the pressure side. As the density ratio (R_d) increases, the film cooling effectiveness in the upstream region of the endwall is gradually improved, however, the effect of the R_d on the film cooling in the downstream region of the endwall is reduced due to the intensity of the passage vortex quickly increases along the mainflow direction. In addition, the leakage flow greatly improves the average surface film cooling effectiveness of the endwall, particularly when R_mf1=1.75%, the average surface cooling effectiveness is increased by 77.8%.