Research on kinetic simulation of methane–air nanosecond pulse discharge plasma under wide operating conditions

To obtain the kinetic characteristics of nanosecond pulse discharge plasma under a wide range of operating conditions (gas pressure Pg = 0.1–60 atm; initial temperature Tg0 = 180–340 K; reduced electric field E/N = 50, 150–500 Td; pulse width τ = 10–50; pulse frequency f = 1–200 kHz), a new methane–air nanosecond pulse dielectric barrier discharge plasma kinetic model was established, which includes a total of 74 species and 742 elementary discharge reactions. The model contains 23 kinds of particles participating in 80 electron collision reactions. Based on the verification of the simulation models for air and methane–air mixture respectively, the plasma kinetic characteristics were studied from both the variations of environmental parameters and actuator control parameters. The results show that the reduced electric field is the most core parameter controlling electron collision reactions. For the four representative particles with relatively high number densities, that is O, H, CH3 and NO, the number density of each particle decreases with the increase of pressure or initial temperature. Increasing the reduced electric field, pulse repetition frequency or pulse width leads to higher maximum number densities of the key active species O, H, CH3 and NO, demonstrating favorable conditions for active species production. The results can provide fundamental plasma data support for investigations on non-equilibrium plasma-assisted combustion of power devices under wide operating conditions.