叶片安装角对离心压气机扩压器气动性能及失速机理影响研究

In order to investigate the induced effect of abnormal vanes of centrifugal compressor diffuser on the stall phenomenon, a high-speed centrifugal compressor with vaned diffuser was taken as the research object. The unsteady numerical simulation was carried out by changing the vane stagger angle of the diffuser wholly or partially, and the results were compared with the experimental results to study the influence rule of the vane stagger angle variation on the performance, dynamic characteristics and stall mechanism of the centrifugal compressor. The research results show that selecting the vane stagger angle in the full negative direction will make the diffuser more unstable. From -5° to 5°, the mass flow rate corresponding to the highest efficiency point increases gradually. For the diffuser with the vane stagger angle deflection of +5°, the flow separation near the shroud wall occurs at the leading edge of the diffuser blade, which induces the backflow in the vaneless space. And for the diffuser with the vane stagger angle deflection of -5°, the flow separation near the hub of the diffuser mainly occurs at the trailing edge, resulting in a large range of backflow near the suction surface of the diffuser blade. When the stagger angle deflection of a single blade is larger than 10 degrees, the diffuser stall comes earlier than the impeller, and the stall mechanism may change with the increasement of the stagger angle deflection.