关键词: 叶栅, 等离子体流动控制, 拓扑, 优化, 旋涡, 奇点

Abstract: To discover the rule of flow loss generation and distribution as well as mechanism of plasma aerodynamic actuation in highly loaded compressor cascade, research on the establishment and verification of simulation model, flow separation structure of basic flowfield and plasma flow control is conducted with topology analysis and numerical method. The total pressure loss coefficient distribution, topology structure, surface streamline patterns and three-dimensional streamlines distribution as well as vortex structure are analyzed, and analysis of optimized actuation layouts are conducted. Results show that three pairs of additional singular points of surface topology strucutre generate with the increase of angle of attack. Plasma actuation changes solid surface topology structure. One pair of additional singular point of surface topology structure ge- nerates with plasma actuation and one more reattachment line appears, which break the the separation line on suction surface at angle of attack of 2°. There are five principal vortices inside the cascade passage. The radial coupling-vortex greatly promotes the fluids carried by passage vortex to move in spanwise direction and becomes the main part of backflow on suction surface. Corner vortex exists independently and its strength and scale are hardly affected by plasma actuation. Suction surface streamwise actuation can have better effect on the flowfield near midspan than the angular region. Endwall pitchwise actuation can prevent the flow separation in corner region except for the flowfield near midspan. Combined actuation can obviously prevent the flow separation for the whole blade span. Endwall transverse movement has greater influence on flow separation structure in corner region than separated suction side boundary layer. Optimized suction side streamwise actuation obviously reduce the capability of preventing boundary layer separated flow, but the optimized endwall pitchwise actuation and combined actuation retain and enhance the performance of plasma flow control.

Key words: cascade, plasma flow control, topology, optimization, vortex, singular point