Large eddy simulation of a turbulent non-premixed flame based on the flamelet-generated manifolds approach and a reduced mechanism verification

This work presents the design of a large eddy simulation based on the flamelet-generated manifolds (FGM) approach to evaluate a Sandia Flame D, which is a turbulent non-premixed piloted jet flame. The detailed kinetic mechanism of the Gas Research Institute (GRI3.0, which contains 53 species and 325 elementary reactions), as well as a reduced mechanism, are employed to describe combustion. This reduced mechanism, containing 19 species and 68 elementary reactions, is proposed based on the direct relation graphs with error-propagation (DRGEP) method and a species sensitivity analysis from the GRI3.0. Both the two mechanisms are introduced into Fluent to simulate a Sandia Flame D, and the numerical results are in good agreement with the experimental data, which indicates the accurate predictive capability of the LES/FGM method in combustion modeling and that the proposed reduced mechanism can be applied to the numerical simulation in practical engineering problems.