Control of thermo-acoustic instabilities using pulse width modulation

An experimental study of a closed-loop control system to suppress thermo-acoustic combustion instabilities is described. The control mechanism relies on out-of-phase heat addition by means of an auxiliary fuel injector. Pulse width modulation is used to precisely control the amplitude and phase of the auxiliary fuel pulses. The controller was successfully implemented in a numerical simulation of a dynamic combustion instability and experimentally.