A numerical determining of the critical conditions for spark ignition and yielding of a stable combustion of a lean methane-air mixture

A mathematical model and solution to the problem of spark ignition of a lean methane-air mixture are presented. The work is aimed to find a minimum value of the spark ignition energy which makes it possible to initiate a combustion of the lean methane-air mixture followed by a stable mode of flame front propagation. The problem is numerically solved using the algorithm of the decay of an arbitrary discontinuity by Godunov's method. Based on the problem solution, the dependence of a minimum energy of spark ignition on the content of a combustible component in the gas is determined. The apparent and normal velocity of flame front of methane-air mixture are obtained as functions of fuel-air equivalence ratio. The calculated results are in a good agreement with data from scientific literature.