气冷涡轮前缘冷气射流角度优化研究 *

Optimization Research of Cooling Gas Injection Angle at Leading Edge of Air-Cooled Turbine

关键词:  气冷涡轮  冷却效率  气膜冷却  复合角度  数值模拟

Key words:  Air-cooled turbine  Cooling effectiveness  Film cooling  Compound angle  Numerical simulation

摘要:

为了研究复合角度的圆形气膜孔对涡轮叶片冷却效果和气动性能的影响，利用SST的k-ω模型对涡轮叶栅进行数值模拟，对前缘区域冷却孔进行复合角度优化设计，给出前缘滞止线附近和吸力面改型前后的冷却特性分析。结果表明圆形气膜孔的复合角度对冷却和气动的影响明显，在前缘压力面，侧向角分别为85°，60°和45°，冷气在前缘处改变滞止点的位置，切向速度增大，冷却效果显著增强。在前缘吸力面上，冷却孔的入射角从45°变为30°，侧向角由-15°改为0°和30°，冷气与主流掺混减弱，壁面冷却效率增大，同时影响近壁面的主流从而改变流场结构。

Abstract:

In order to study the compound angle of circular film cooling holes on the cooling and aerodynamic performance of turbine blade，SST k-ω model was used to simulate the cooling holes on leading edge area ，which gives the cooling characteristics on stagnation line on leading edge and section side before and after retrofit. The results show that the compound angle of circular film-cooling hole does a great impact on cooling and aerodynamic performance. On pressure side of leading edge，the lateral angles of 85 °，60 ° and 45 °，the cooling air changes the position of stagnation point at leading edge，with the tangential velocity increasing，and the cooling effect is significantly enhanced. On section side of leading edge，the incident angle turns from 45°to 30°，the lateral angle changes from -15 ° to 0 ° and 30 °，the cooling air mixed with the mainstream is weaken to improve the cooling efficiency. Meanwhile ，it affects the mainstream near the wall and changes the structure of flow field.