Distributed control-oriented modeling of thermoacoustic dynamics in a duct

In this paper, we consider the problem of control-oriented modeling of the thermoacoustic dynamics of ducted, premixed bluffbody stabilized combustion. We make a simplifying assumption of ignoring the vortex dynamics, but retain the effects of burning and fuel actuation. The thermoacoustic model arises as an interconnection of acoustics and heat-release submodels. For acoustics, we model the effects of mean reacting flow and for heat-release, we model the effects of distributed flame and fuel dynamics. We carry out a control-oriented analysis of the resulting coupled thermoacoustic model that highlights the important role of density ratio in obtaining combustion instability.