REDUCED MODEL OF CHEMICAL KINETICS OF DETONATION COMBUSTION OF METHANE

For modeling of chemical transformation in the methane-air mixtures, instead of a detailed kinetic scheme of more than 2,000 elementary reactions in relation to mine explosions, the two-stage model of the kinetics, allowing also consider supplements of water vapor and inert diluents, to assess their impact on the suppression of blast waves is proposed. The model includes a single differential equation to calculate the molar mass of the gas after the induction period and the explicit algebraic formulas for calculating the thermal effect, the internal energy, heat capacity and adiabatic exponent of a mixture. The suggested model is used in numerical two- dimensional calculation of multifront detonation waves in methane-air and methane- oxygen mixtures. Results of calculation of parameters, structure and size of the detonation cell (stoichiometric methane-air and methane-oxygen mixtures it turned to 34 ± 1 cm and 0.30- 0.35 cm) correspond well to the available experimental data.