小型离心压气机径向扩压器复杂涡系结构分析

Detailed numerical simulation was carried out for a small centrifugal compressor. The complex vortex structure in the radial diffuser with splitter vanes under the design, chock and stall conditions was mainly analyzed and the complex vortex structure model of the radial diffuser was constructed. The research result shows that the internal vortex structure of radial diffuser mainly includes leading edge vortex ( LEV), two passage vortexes ( passage pressure side and suction side) and throat vortex. The leading edge vortex formed on the suction surface of the main blade is formed by the pressure gradients in the spanwise and flow direction of low energy fluid on the casing side, and the throat vortex is composed of the reverse flow of passage vortex on suction side along the leading edge of splitter vanes and leading edge vortex. The accumulation of the throat vortex at the throat is the cause of the stall of the radial diffuser, and the shock wave at the throat of the radial diffuser is the cause of the chock. The smaller the flow rate is,the closer the vortex core of the leading edge vortex moves toward the pressure surface of the adjacent main blades.