采用附面层抽吸(BLS)控制流动分离的数值模拟

Numerical investigation on application of boundary layer suction to control the flow separations

关键词:  航空发动机  叶栅  附面层  边界层分离  边界层吸附  数值仿真

Key words:  Aircraft engine  Cascade  Boundary layer  Boundary layer separation  Boundary layer suction  Numerical simulation

摘要:

采用数值模拟的方法,研究了附面层抽吸(BLS)对两种具有不同分离特征的叶栅流场的气动影响。通过比较抽吸前后极限流线谱和叶栅损失的变化,对抽吸前后的流场进行定性分析。结果表明,采用附面层抽吸技术可以明显改善大转角、大分离叶栅的气动性能。其中,对以闭式分离为主要特征的叶栅流场,其最佳抽吸位置为主分离区的起始位置,即鞍点附近;对以开式分离为主要特征的叶栅流场,其最佳抽吸位置位于主分离区的上游。

Abstract:

A numerical simulation was performed to analyze the effect of boundary layer suction on the cascades with different separation structure.By comparing the limiting streamlines patterns as well as the loss distributions of the original cascade with that of the cascade with BLS,a qualitative analysis of the flow fields was obtained.The results show that boundary layer suction(BLS) can improve the aerodynamic performance of the cascade with high turning angle and serious flow separation distinctly.For the cascade with the main character of closed separation,the optimal suction position is just at the staring point(saddle point) of the closed separation.For the cascade with the main character of open separation,the optimal suction position is at the upward of the separation region.