INTEGRATED CONTROL OF ROTATING STALL AND SURGE IN HIGH-SPEED MULTISTAGE COMPRESSION SYSTEMS

Aeroengines operate in regimes for which both rotating stall and surge impose low-flow operability limits. Thus, active control strategies d esigned to enhance operability of aeroengines must address both rotati ng stall and surge as well as their interaction. In this paper, a prev iously developed nonlinear control strategy that achieves simultaneous active control of rotating stall and surge is applied to a high-speed three-stage axial flow compression system with operating parameters r epresentative of modem aeroengines. The controller is experimentally v alidated for two compressor builds and its robustness to radial distor tion assessed. For actuation, the control strategy utilizes an annulus -averaged bleed valve,with bandwidth on the order of the rotor frequen cy. For sensing, measurements of the circumferential asymmetry and ann ulus-averaged unsteadiness of the flow, through the compressor are use d. Experimental validation of simultaneous control of rotating stall a nd surge in a high-speed environment with minimal sensing and actuatio n requirements is viewed as another important step toward applying act ive control to enhance operability of compression systems in modern ae roengines.