涡轮端壁气膜冷却效果数值模拟

摘要

Four rows of cylinder film cooling holes were allocated at the turbine cascade endwall with axial blade chord of 21 %,51 % and 81 % and upstream of leading edge of 9%,by the CFD method.The standard k-εturbu-lence model was applied to simulate cooling effect of the endwall with single angle and compound angle film-holes. The results show that,the advantage of compound angle jet could be well demonstrated when the incidence angle αreached 30°,at which time the average cooling efficiency of the compound angle jet was 1 6.4% higher than that of the single angle jet.With an increase in blowing rate,the cooing efficiency drop was getting slower.The compound angle jet will cause reverse asymmetric vortexes,which strengthens the wall-attachment of the film to some extent and is helpful to the steam film cooling.%采用 CFD 方法在叶栅端壁21％，51％，81％轴向弦长和前缘上游9％轴向弦长端壁处布置4排圆柱形气膜冷却孔，选用标准κ-ε模型模拟分析端壁单一角度与复合角度射流的冷却效果。结果表明：复合角度射流优势在入射角α＝30°时最明显，此时复合角度射流平均冷却效率比单一角度射流平均冷却效率增加16．4％；随着吹风比增加，射流孔附近冷却效率下降速度变慢；复合角度射流的引入会导致反向涡不对称，加强了气膜的贴壁性，更有利于汽膜冷却。