高负荷压气机叶栅等离子体流动控制数值仿真与拓扑分析

Numerical Investigation and Topological Analysis of Plasma Flow Control on a Highly Loaded Compressor Cascade

关键词:  等离子体气动激励  压气机  叶栅  拓扑结构  角区 

Key words:  Plasma aerodynamic actuation  Compressor  Cascade  Topology structure  Corner

摘要:

为揭示叶栅等离子体流动控制的影响规律与作用机理,对等离子体气动激励前后高负荷压气机叶栅内部流动和拓扑结构进行了对比研究。结果表明:等离子体气动激励抑制叶栅流动分离的作用效果最明显的区域位于总压损失区域与主流区域的边界上；不同等离子体气动激励布局,对固壁面拓扑结构以及奇点总数的影响规律不同；吸力面流向激励通过增强附面层流体抵抗逆压梯度的能力,可以改善叶栅中间叶高流动特性;端壁横向激励通过抑制横向流动,抑制角区流动分离能力较强,并改变叶片展向的负荷分布；组合激励结合了吸力面流向激励和端壁横向激励的作用优势,因而提高叶栅气动性能、降低流动损失的效果最好。 

Abstract:

In order to find the influence law and mechanism of plasma flow control, flow structure and topology structure of highly loaded compressor cascade with and without plasma aerodynamic actuation (PAA) were studied. Results show that the area, where PAA prevents flow separation most effectively, is located at the verge of triangular region with high total pressure loss and main flow. The solid surface topology structure and distribution of singular points are changed with different PAA layouts, but the number relation between saddle and node points keeps constant. The streamwise PAA on the suction surface can mainly change the flow characteristic at midspan, but has weak impact on corner separation. The pitchwise PAA on the endwall can reduce the accumulation of low-energy fluids at the suction surface and endwall corner by inhibiting the cross flow, and then change the blade loading distribution in spanwise direction. The control effect of streamwise PAA on the suction surface combined with pitchwise PAA on the endwall is among the best. 