ROTATING STALL CONTROL VIA BIFURCATION STABILIZATION

Rotating stall is a fundamental aerodynamic instability in axial how c ompressors, induced by nonlinear bifurcation. It effectively reduces t he performance of aeroengines. In this paper classical bifurcation the ory is used to derive output feedback control laws in which throttle p osition is employed as actuator and pressure rise as output measuremen t. The challenge to the proposed control system is that the critical m ode of the linearized system corresponding to rotating stall is neithe r controllable nor observable. Using the projection method from Iooss and Joseph (1980), and Abed and Fu (1986), it is shown that linear out put Feedback controllers are adequate for bifurcation stabilization. B oth linear and nonlinear feedback control laws are proposed and are sh own to be effective in elimination of hysteresis loop associated with rotating stall, and in extending the stable operating range of axial h ow compressors. (C) 1998 Elsevier Science Ltd. All rights reserved.