非对称端壁造型对离心压气机性能的影响

The application of non-axisymmetric endwall profiling on both axial compressors or turbines has been determined to be an effective way to increase the efficiency. In order to investigate the effects of non-axisymmetric end wall profiling on the performance of centrifugal compressors, four endwall contouring schemes according to the design experience of non-axisymmetric endwall profiling in axial compressors were performed on a vaned diffuser centrifugal compressor with the help of Autoblade and CFX software. Numerical investigations were conducted on a radial compressor with vane diffuser. The results showed that non-axisymmetric profiled endwall PEW1_10% which was convex near the pressure side and concave near the suction side extended the compressor characteristic performance curve to smaller and higher mass flow rate points which gave a 11.8% improvement of the operating range with no reduction of the efficiency compared with the original compressor. Analysis of the flow field showed that PEW1_10% caused a redistribution of the flux in the diffuser passage at the near surge condition, which further led to an increase of the radial velocity near the suction side and a decrease of the low-energy fluid. As a result, the flow condition in the diffuser passage was improved, and the surge was delayed.