Large-Eddy Simulation of Combustion Dynamics of Lean-Premixed Swirl-Stabilized Combustor

A comprehensive numerical study of the combustion dynamics in a lean-premixed swirl-stabilized combustor is described. The analysis treats the conservation equations in three dimensions and takes into account e niterate chemical reactions and variable thermophysical properties. Turbulence closure is achieved using a largeeddy-simulation technique. The compressible-e ow version of the Smagorinsky model is employed to describe subgrid-scale turbulent motions and their effect on large-scale structures. A level-set e amelet library approach is used to simulatepremixed turbulent combustion. The governing equationsand theassociated boundary conditions aresolvedbymeansofafour-stepRunge‐ Kuttaschemealongwithimplementationofthemessagepassinginterface parallel computing architecture. The analysis allows for a detailed investigation into the interaction between turbulent e ow motions and oscillatory combustion of a swirl-stabilized combustor. Several physical processes responsible for driving combustion instabilities in the chamber have been identie ed and quantie ed, including the mutual coupling between acoustic wave motions, vortex shedding, and e ame oscillations. In particular, the mechanisms of energy transfer from chemical reactions in the e ame zone to acoustic motions in the bulk of chamber are carefully studied.