Flow Mechanism of the Shock Structure and Secondary Flow Control in a Supersonic Compressor with a Nonaxisymmetric Endwall

Shock is the main characteristic of supersonic compressors. There are relatively few studies of the control of shock structure and secondary flow in supersonic compressors by nonaxisymmetric endwall optimization. The lack of understanding of the mechanism of flow structure changes in supersonic compressors by the nonaxisymmetric endwall limits the application of this technique in supersonic compressor interiors. In this paper, the effects of nonaxisymmetric endwall on the supersonic compressor and flow mechanism were studied using the numerical simulation method and verified by experiment. The results showed that the optimized nonaxisymmetric endwall design increased the peak isentropic efficiency of the supersonic compressor by 0.6%, verifying the effectiveness of the nonaxisymmetric endwall in improving the supersonic compressor. By comparing the flow fields at the peak efficiency points before and after optimization, it was found that the shock loss in the rotor was reduced by the change of shock structure induced by the nonaxisymmetric endwall, and the secondary flow loss was controlled by the change of shock structure in the rotor. Moreover, the rotor’s nonaxisymmetric endwall changed the downstream stator’s inlet conditions, reducing the stator’s total pressure loss. Therefore, the nonaxisymmetric endwall has a wide range of applications for regulating the internal shock structure of supersonic compressors.