几何结构对后台阶缝隙气膜冷却效率的影响

1引言在现代高性能航空发动机中,涡轮叶片的尾部往往是高温部位,也最容易受热腐蚀而损坏,主要原因是叶片后部燃气侧流动往往已发展为湍流,使该部位换热强度很大,同时也降低了上游喷出冷气的冷却效率,叶片内部冷气经途中吸热,到达尾部时温度也相对较高,冷却作用也相对较小。因此

Effect of geometry of back-step slots on film cooling

Film cooling effectiveness of back-step three dimensional slots injection, which modeling the trailing edge cooling of turbine blade, was measured at the slot center line and rib center line. The effects of geometry of slot on film cooling effectiveness were studied. The ratio of slot width to rib width changed from 0.67 to 1.5 and ratio of lip height to slot height changed from 0.5 to 1.89. The experimental results show that the profile of film cooling effectiveness is different at the slot center line and rib center line. Both ratios of slot width to rib width and lip height to slot height have evident influence on the film cooling effectiveness. The sizes of three dimensional mixing flow region increases with the increase of both ratio of slot width to rib width and lip height to slot height.