离心叶轮局部粗糙度对其气动性能的影响

The aerodynamic performance of centrifugal impeller has an important influence on the overall performance of compressor. To investigate the deterioration degree of centrifugal compressor caused by local surface roughness and its mechanism, the flow passage of Krain impeller was divided into several regions by numerical simulation method. Besides, different schemes were set to research the object. The results show that the rough blades are more likely to deteriorate the impeller performance than the rough hub and shroud. The isentropic efficiency at the design point decreases by 2.466% compared with the smooth condition, and the corresponding total pressure ratio decreases by 6.266%. The choke flow rate decreases by 2.227%. The roughness on the hub changes the blade load distribution by affecting the tip clearance leakage flow. The roughness on the leading edge of impeller increases the interaction between boundary layer and shock wave, making the flow passage more easily blocked. Additionally, the performance of the impeller is more sensitive to the roughness on the suction side than that on the pressure side.