Uncertainty propagation in a reduced order thermo-acoustic model

Abstract

We present a thermo-acoustic model on a cylindrical, or annular, domain capable of modeling instabilities of tangential acoustic modes. The model accounts for non-uniform density, damping, rotational flow, and heat-release coupling. It is shown that deliberately introducing spatial variations in some quantities have a similar effect to adding damping to the system. The effects of these symmetry-breaking concepts are evaluated on the model through linear analysis and the net amount of additional damping is computed. We show how various symmetry-breaking concepts are robust with respect to the uncertainty in the model parameters and we examine propagation of uncertainty with respect to a recently defined measure of uncertainty.