Effect of Pulse Polarity and Dielectric Configuration on the Spatio-Temporal Evolution Characteristics of Methane Pulsed Dielectric Barrier Discharge Plasma

Plasma assisted CH
4
directly converse into higher hydrocarbons has received particular attention in controlling the energy depletion and environmental pollution. The current work establishes the kinetic model of methane pulsed dielectric barrier discharge (DBD) plasma to investigate the spatio-temporal evolution characteristics under the double dielectric positive pulsed DBD (DDBD), single dielectric positive pulsed DBD (S
P
DBD), and single dielectric negative pulsed DBD (S
N
DBD) at atmospheric pressure. The results show that the emergence of peak values (discharge current densities, average electron temperatures and densities.) are later and smaller under DDBD compared with that under S
P
DBD and S
N
DBD. In DDBD, the distributions of the species are uniform over the plasma area at the beginning of the discharge, and then move toward the anode, gradually the species accumulate towards the cathode with the cathode sheath formed. As the discharge proceeding, the species principally distribute on the cathode. Unlike the DDBD, the majority of the species are concentrated on the anode at the start of discharge under S
P
DBD, then the species move toward the cathode over time. And the species mainly distribute on both electrodes. Furthermore, the species spatial distributions under S
N
DBD are symmetrical to that in S
P
DBD.