Development of a novel subgrid combustion model for buoyant turbulent diffusion flames

A novel approach is presented to incorporate finite rate reactions in modeling of turbulent diffusion flame, with the existence of unresolved flamelets inside the CFD grid cells taken into account. This approach, called SCM (subgrid combustion model), is applied in large eddy simulations of the UMD line burner flames. With the global kinetic parameters fitted for the measurement data and detailed simulations of autoignition in stoichiometric methane-air mixture, as well as for the extinction strain rate in the opposed non-premixed jets, the SCM model is shown to replicate the mean temperature profiles in unsuppressed flame with mean total heat release of 50 kW. For flame suppression via dilution of the oxidizer flow by nitrogen, the lift-off and extinction of non-anchored flame are predicted in agreement with the experimental data. The SCM is designed as a tool to allow for the finite rate kinetics effects in large eddy simulations of buoyant turbulent diffusion flames, with the focus on weakly turbulent regions, in which applicability of conventional combustion models is limited.

Automated summary

A novel approach is proposed to incorporate finite rate reactions in modeling of turbulent diffusion flame. The approach, called SCM, is applied in large eddy simulations of flame combustion and shows promising results in replicating flame behavior under different scenarios.