Conversion of a propane−air mixture with fuel content below or near the lower flammability limit has been examined. Conversion is initiated by a nanosecond pulsed-periodic discharge with a pulse repetition rate of 2.5 MHz. In a one-dimensional approximation, the evolution of the mixture composition along the discharge channel radius is studied as a function of pressure (at the same current amplitude), fuel content in the mixture, discharge duration (total energy input), and the duration of the relaxation phase after the discharge ends. The simulation results revealed individual stages of the interaction between the discharge plasma and the lean fuel mixture, demonstrating positive effects, such as the production of conversion products C2H4, C3H6, H2, CO, NO, etc. at an early stage due to the formation of radicals in an electric field of E/N = 100–300 Td, and negative effects, which lead to the complete combustion of intermediate hydrocarbons and the formation of high CO and CO2 concentrations during prolonged operation of the discharge.
Bocharov et al. (2026) studied this question.