LARGE-EDDY SIMULATION OF REACTING FLOWS APPLIED TO BLUFF-BODY STABILIZED FLAMES

The objective of this paper is to present a large eddy simulation mode l for chemically reacting Bows. The large eddy simulation model, found ed on a physical model based on modern continuum mechanics, includes a complete treatment of the subgrid stresses and fluxes including both backscatter and diffusion. To investigate the predictive capabilities of the large eddy simulation model, numerical simulations of a configu ration corresponding to a rig consisting of a rectilinear channel with a triangular-shaped bluff body have been performed. Both nonreacting and reacting flows have been examined under a variety of operating con ditions. This paper focuses on the reacting case, which is characteriz ed as lean and premixed. The simulation results are compared to experi mental measurements of temperature, constituent mass fraction, and vel ocity fields in the test rig. The results indicate that the large eddy simulation technique works well and mimics most of the significant Bo w features, including the typical unsteady Bow structures. The results from the large eddy simulations are furthermore used to investigate t he mechanisms responsible for the typical flowfield in a bluff body st abilized flame.