出流结构对涡轮导叶端壁气膜冷却数值研究

通过对涡轮叶栅端壁上游不同气膜冷却结构模型进行数值模拟，得到了不同吹风比情况下，涡轮叶栅端壁的流动与换热特性。结果表明：圆柱型孔冷气射流在孔下游与主流相互作用形成一对转动方向相反的耦合涡，对涡轮叶栅端壁的气膜冷却效果不利。前向扩张孔降低了孔下游耦合涡的强度，对涡轮叶栅端壁总体气膜冷却效率要优于圆柱型孔。前向扩张缝结构增大了射流宽度，冷却了孔间端壁，对涡轮叶栅端壁总体气膜冷却效率要优于圆柱型孔和前向扩张孔。

Numerical study on film-cooling effectiveness on the endwall of first vane by different film-cooling jet structure

Numerical simulation was carried out to investigate the influence on film-cooling effectiveness by different structure, obtained the flow and heat transfer characteristic of endwall on different blowing ratio. Result shows that the jet of column holes produces a coupling of counter-rotating vortices at the downstream of cooling holes by the influence of mainstream and cooling jet. The vortices are disadvantages to the endwall film-cooling. The forward expansion hole reduces the intensity of coupling vortices. The cooling jet was pushed to the wall. These factors make its cooling effectiveness better than the column cooling holes. The forward expansion leakage increases the width of jet, cools the endwall between the film-cooling holes. These factors make the forward expansion leakage better than the column holes and forward expansion holes.