Control of an axial flow compressor via pulsed air injection

Raffaello D'Andrea, Control and Dynamical Systems, Caltech

In this talk, we present results on the use of pulsed air injectors to control the onset of stall in a low-speed, axial flow compress or. By measuring the unsteady pressures in front of the rotor, a control algorithm determines the location and magnitude of a stall cell and controls the injectio n of air in front of the rotor face. Experimental results have verified that this control scheme slightly extends the stall point of the compressor and eliminates the hysteresis loop normally associated with stall. This effect may be explained based on the experimentally determined, quasi-stea dy effects of air injection on the compressor characteristic curve as an actuation scheme for a non-linear 3 state system model.