Numerical study of exhaust chemical composition in a methane DBD plasma actuator under different operating conditions

Abstract

In this paper, numerical simulations of a Dielectric-Barrier Discharge (DBD) plasma actuator are performed to predict its output chemical composition. The plasma actuator is cylindrical, with two coaxial electrodes and a quartz dielectric. The electrical discharge occurs in a pulsed manner around the quartz wall. This device is utilized for methane conversion in plasma-assisted combustion applications. The effects of voltage, frequency, temperature, and relative permeability parameters on methane conversion and some selected species concentrations were investigated. The results show that plasma discharging converts methane to hydrogen and heavier hydrocarbons such as C2H3, C2H4,C2H5, C2H6, and C3H8. Moreover, increasing the relative permeability coefficient and voltage had the greatest effect on methane conversion. Increasing the relative permeability from 2 to 6 increases the methane conversion by 43 % and also increases the H2 density by 57 %. The conversion rate of methane and the H2 density increase by 18 % with increasing the voltage from 6 to 8 kV. The partial conversion of methane to hydrogen and radical species benefits combustion applications in terms of flame stability and emissions reduction.