Combustion characteristics of H_2/N_2 and H_2/CO syngas nonpremixed flames

摘要

Turbulent nonpremixed H_2/N_2 and H_2/CO syngas flames were simulated using 3D large eddy simulations coupled with a laminar flamelet combustion model. Four different syngas fuel mixtures varying from H_2-rich to CO-rich including N_2 have been modelled. The computations solved the Large Eddy Simulation governing equations on a structured non-uniform Cartesian grid using the finite volume method, where the Smagorinsky eddy viscosity model with the localised dynamic procedure is used to model the sub-grid scale turbulence. Non-premixed combustion has been incorporated using the steady laminar flamelet model. Both instantaneous and time-averaged quantities are analysed and data were also compared to experimental data for one of the four H_2-rich flames. Results show significant differences in both unsteady and steady flame temperature and major combustion products depending on the ratio of H_2/N_2 and H_2/CO in syngas fuel mixture.