离心叶片进出口几何形状对气动性能影响研究

To study the impact of the blade inlet and outlet geometry on the internal flow field and aerodynamic performance of the centrifugal impeller, the leading and trailing edges of the blade-inlet and outlet were respectively rounded with different dimensions on a centrifugal impeller taken as the research object. The SST turbulence model and the High Resolution numerical method were used for periodic single channel numerical simulation of the centrifugal impeller, and the impact of the geometric shape produced by the rounding with different dimensions of the leading and trailing of the blade on the internal flow field distribution and aerodynamic performance of the centrifugal impeller was studied in this paper. The results showed that the flat-convex rounding of the leading edge of the blade inlet can increase the total pressure ratio and polytropic efficiency of the centrifugal impeller, and reduce the local flow separation loss at the leading edge of the inlet. The smaller the size of flat-convex rounding, the more obvious the increase of polytropic efficiency and total pressure ratio, and the maximum increase of both was about 1% at the design op-crating point. Rounding the pressure surface at the trailing edge of the blade can increase the pol-ytropic efficiency of the centrifugal impeller, but reduce the total pressure ratio of the centrifugal impeller. Rounding the suction surface at the trailing edge can simultaneously increase both the polytropic efficiency and the total pressure ratio of the centrifugal impeller, making the maximum polytropic efficiency increase by about 1 % and the maximum total pressure ratio increase by about 5% under the design condition, and reducing the wake loss when the air flows out of the impeller. The flat-convex rounding of the blade leading edge in small size and of the trailing edge suction surface in large size can not only reduce the local flow loss at the inlet and outlet of the blade, but also increase the polytropic efficiency by about 1. 5% and the total pressure ratio by about 7% at the design operating point. Furthermore, it can improve the performance of the centrifugal impeller, providing a reference for the design optimization and efficient machining and manufacturing of the centrifugal blade.