Modeling Premixed Combustion-Acoustic Wave Interactions: A Review

The interactions between acoustic waves and a premixed combustion process can play an important role in the characteristic unsteadinessof combustiondevices. Inparticular, theyareoftenresponsible for the occurrence of self-excited, combustion-driven oscillations that are detrimental to combustor life and performance. A tutorial review is provided of current understanding of these interactions. First, the mutual interaction mechanisms between the combustion process and acoustic, vorticity, and entropy waves are described. Then, the acoustic– ame interaction literature is reviewed, primarily focusingonmodeling issues. This literature is essentially organized into four parts, depending on its treatment of 1) linear or 2) nonlinear analyses of 1) amelets or 2) distributed reaction zones. A sizeable theoretical literature has accumulated to model the unsteady response of the laminar ame structure, for example, the burning rate response to pressure perturbations. However, essentially no serious experimental effort has been performed to critically assess these predictions. As such, it is dif cult to determine the state of understanding in this area. On the other hand, good agreement has been achieved between well-coordinated experiments and theory describing the interactions between inherent ame instabilities and acoustically induced ow oscillations. Similarly, both the linear and nonlinear kinematic response of simple laminar ames to acoustic velocity disturbances appear to be well understood, as evidenced by the agreement between surprisingly simple theory and experiment. Other than kinematic nonlinearities, additional potential mechanisms that introduce heat