Two-Dimensional Numerical Simulation of Explosion for Premixed CH4-O2-N2 Mixture

Based on the reduced methane oxidized element reaction model, CFD software and ISAT algorithm were used to establish a two-dimensional turbulent explosion model for premixed CH4-O2-N2 mixture. Computational results show that the process of ignition, combustion and explosion of the premixed CH4-O2-N2 mixture can be simulated well by the model. The influence of the initial temperature of the high temperature core and the component of mixture on combustion and explosion were considered in the numerical computations. Simulation results indicate that the initial temperature of the high temperature core has an important effect on the ignition delay time and the early combustion phase of the premixed CH4-O2-N2 mixture, but it hardly affects the CJ deflagration phase. The reaction activity of the premixed mixture is reduced by adding N2, which results in the increase of ignition delay time and the decrease of deflagration reaction speed, explosion overpressure and free radical concentration. The computational results of explosion overpressure are in good agreement with experimental results on the same conditions.