Numerical Simulation of Stall Transients of Axial Compression Systems With Inlet Distortion

In this paper, a theory is provided to predict how rotating stall will develop in axial compression systems both with uniform and nonuniform inlet flow, which simulates rotating stall using a time step integration procedure of the two dimensional, compressible and unsteady Euler equation, and also adopts the “actuator disk” to replace the compressor. Using this theory, the effect of various kind of inflow nonuniformity on both rotating stall and recovery transients, and the problem of active control/suppression of rotating stall can be numerically analysed. Rotating stall transients and its growth process both with uniform and with circumferential total pressure distorted inlet flow are investigated in detail. It has been found that rotating stall was preceded by a period in which small amplitude waves travel around the circumference and evolved smothly into rotating satll without sharp change in phase or amplitude both with uniform and with distorted inflow. The throttle ramping and the inlet distortion have crucial effect on the period and stall transients.