Large eddy simulation of methane non-premixed flame using the laminar flamelet model

The large eddy simulation (LES) using the steady laminar flamelet model is applied to a simple turbulent jet flame with 33.2% H2, 22.1% CH4 and 44.7% N2 at the Reynolds number of 15,200 in order to validate the numerical methods and to investigate the flame structure. For the validation, the detailed experimental data of DLR-A flame is used. The numerical results are in reasonable agreement with experimental results except mass fractions of minor species. In the flow field, the break-down of the potential core, the vortex structure and the mixing intensity are well captured. In the combustion field, mass fractions of major species (H2O, CO2, CO) are well predicted quantitatively. Minor species are well predicted qualitatively. In the present study, the simulations conducted on the Cartesian and cylindrical grids with approximately 6.6× 105 nodes are compared.