LES-DFSD studies of lean-burn turbulent premixed hydrogen flames

Large eddy simulation (LES) based turbulence modelling technique may face challenges when employed to predict turbulent reacting flows. The Dynamic Flame Surface Density (DFSD) model for turbulent premixed combustion applied in this research adapts to produce accurate results based on the information obtained from transient flames. A LES – DFSD model has been developed and validated against experimental data for lean-burn premixed hydrogen flames propagating past repeated obstacles and a solid obstruction of varied area blockage ratio (ABR). The rate of pressure rise, peak overpressure magnitude, flame speed and other flame characteristics have been successfully reproduced numerically for flow configurations. It was found that having a combustion filter-width which is 6 to 7 times the smallest computational grid cell size produced the best overpressure and flame speed results. The numerical results from the LES – DFSD co-simulations produced good agreement with available experimental data.