Numerical research on impact of air system bleeding on compressor performance

Bled air from the high pressure compressor takes up 3%-5% in the air system. However, there are not many studies on the compressor performance after bleeding. By analyzing the low-speed single-stage compressors, six bleeding structures are presented according to their influence mechanism on the compressor performance, and five kinds of bleeding rate are applied to one of the structures. A numerical simulation is performed to study the influence of bleeding rates and structures on the compressor performance. The results show that for the stators with the large flow separation in the corner, bleeding a small amount of air from the end-wall region can improve the total pressure increase and the stability margin. Moreover there is an optimum value of the bleeding rate in the stator casing.