Combined air injection control of rotating stall and bleed valve control of surge

A controller for rotating stall in axial flow compressors using pulsed air injection is considered. Theory is developed for the combination of this air injection controller with a bleed valve controller for the system's surge dynamics. The controller analysis is based on the surge dynamics acting on a slow time scale relative to the rotating stall dynamics. Experiments demonstrating this controller design on the Caltech rig are also presented.