Active control of combustion instabilities using model-based controllers

An implementation of active control of thermoacoustic instabilities on a swirl-stabilized spray combustor is presented. Loudspeakers were used as control actuators in the closed-loop control scheme. Pressure transducers located in the combustion chamber produced the feedback signal in the control study. Experimental models of the combustor dynamics were developed using a nonparametric identification method. Linear quadratic Gaussian (LQG), LQG/loop transfer recovery, and H ∞ loop-shaping controllers were derived and tested in simulation as well as experimentally. Phase-delay control was used as a baseline method to compare the performance of these different controllers. The advantages of the model-based controllers over the baseline strategy are clearly presented.