斜坡型涡流发生器控制叶栅角区分离的数值模拟

The development of end-wall boundary layer in compressor cascade and the corner separation between suction surface and end-wall are the important reasons for the loss of flow in compressor. In order to minimize the corner separation and improve the aerodynamic performance of the cascade, numerical investigation of compressor cascade with micro-ramp vortex generation(VG) placed inside of end-wall has been investigated. The cascade flow field characteristics are analyzed in detail. Furthermore, the influence of vortex generator on the angle of attack of cascade is studied. The results show that, the ramp-VG placed inside of cascade can resist the crosswise flow, and the streamwise vortex generated by ramp VG can interact with the boundary layer in near end-wall region, resulting in limiting the development of passage vortex from pressure to suction side. Meanwhile streamwise vortex entrains high energy fluid to suction side corner region to increase momentum of corner fluid, making the flow field smoother at the outlet of the cascade. Furthermore, the intensity of streamwise vortex is influenced by both height and aspect ratio of the VG. The optimal scheme of the vortex generator is h=4 mm, b=4 mm, l=12 mm. This scheme reduces the total pressure loss at the outlet section by 7.82%. The vortex generator has the best effect under the design point, with the increase of the positive and negative angles of attack, the degree of loss reduction decreases. When the angle of attack is -8° and 8°, the loss is 1.91% and 5.29% lower than the prototype, respectively.