Rotating stall control via bifurcation stabilization

Rotating stall is a fundamental aerodynamic instability in axial flow compressors, induced by nonlinear bifurcation. It significantly reduces the performance of aeroengines. In this paper classical bifurcation theory is used to derive output feedback control laws in which throttle position is employed as actuator and pressure rise as output measurement. The challenge to the proposed control system is that the critical mode of the linearized system corresponding to rotating stall is neither controllable nor observable. Using the projection method, it is shown that the proposed control system is effective for elimination of rotating stall for the third-order Moore-Greitzer model