Study on the Influence of Blade Outlet Backsweep Angle on Performance of Impeller

Abstract

As an important parameter of compressor impeller, the design value of blade outlet backsweep angle has a great influence on the performance of impeller. In this paper, six impellers with blade outlet backsweep angle β2B equal to 0°, 10°, 20°, 30°, 40°, and 50° were designed to evaluate the influences of impeller backsweep angle β2B on the performance, characteristics of gas flow and equivalent stress using computational fluid dynamics (CFD) and finite element analysis (FEA). Results indicated that the performance curve for the outlet backsweep blade angle β2B of 50° has the largest stable operating range. The isentropic efficiency of the impeller with backsweep angle β2B equal to 40° is 16.8% - 25.9% higher than that of the impeller with backsweep angle β2B equal to 0°. When the blade outlet backsweep angle is 30°, the equivalent stress distribution of the impeller is more uniform, the maximum equivalent stress is the smallest.