Analysis of Ignition Mechanisms of a Stoichiometric Fuel–Air Mixture

The article compares different mechanisms of activation of a stoichiometric methane–air mixture in an adiabatic unit cell of constant volume in the zero-dimensional approximation. The evolution of the mixture composition from the initial state is described by the corresponding chemical kinetics equations using a scheme with 224 reactions for 32 components, which includes the ionized components of the oxidizer and their dependence on the reduced field. The basic mechanism is considered to be activation by a triangular current pulse with a duration of 50 ns with amplitudes that provide the actual energy input for ignition of the mixture under initial atmospheric conditions, i.e., on the order of 1–2 MJ/m³. Idealized cases of the ignition process initiated either by preliminary heating or by partial dissociation of the molecular components of the oxidizer are considered as options for comparison. The determining role of both the total energy input and the characteristic activation power is noted.