Annaswamy We propose to study active control combustion dynamics, with particular emphasis on suppression of thermoacoustic instability. Our approach is to develop a systems framework which will include (a) models for the different components which contribute to the instability, e.g., the heat release dynamics, the acoustic dynamics, the actuator-sensor dynamics, (b) the effect of active feedback control on these components and their mutual interactions, and (c) self-tuning algorithms as part of the control design to allow changes in the operating conditions of the process. Each subcomponent model will be studied in increasing order of complexities which are compatible with practical systems, e.g., heat release dynamic models for bluff body-stabilized combustion, in vortical structures in shear layers, from fuel injectors used as actuators, etc. We will focus on showing, using a systems framework, how an overall controlled combustor model which is synthesized using these component models is capable of describing the subtle dynamic behavior observed in practical systems. Particular attention will be given to an understanding of model-based control strategies that are based on the predicted response of the combustion systems using these models and that account for effects not previously understood, such as coupling among acoustic modes and coupling among different controller components and the combustor. ***
