Large-eddy simulations of turbulent reacting stagnation point flows

A methodology for solving unsteady premixed turbulent flame propagation problems in high Reynolds number (Re), high Damkoehler number spatially evolving flows is developed. The method is based on Large-Eddy Simulation (LES) with a subgrid combustion model based on the Linear-Eddy Model (Kerstein, 1991). An inter-LES cell burning mechanism has been added to the present formulation to account for molecular diffusion (burning) across LES cells which was been neglected in earlier studies. Two-dimensional simulations of passive isotropic flame propagation using the LES-LEM for Re from 100 to 1000 are conducted to validate the subgrid and supergrid propagation mechanisms. Two models are used to simulate turbulent premixed stagnation point flames. The first model is a conventional approach which uses a thin flame model (Kerstein et al., 1988) with and without significant heat release. The second model uses the LES-LEM approach without heat release. Qualitative comparisons between simulations and experimental data are made.