Generation of a Nanosecond Pulsed Gliding Arc Discharge With a Repetition Frequency of 300 kHz in an Air Flow at Atmospheric Pressure

摘要

Characteristics of a repetitive nanosecond pulsed gliding arc discharge in an air flow at atmospheric pressure driven by a SiC MOSFET inverter power supply are reported for the first time. The gliding arc discharge is produced using two diverging electrodes. The repetition frequency of the pulsed voltage is set from 10 to 300 kHz, and the pulse duration is 500 ns. The propagation distance of the gliding arc discharge almost linearly increases with increasing the repetition frequency of the applied pulsed voltage, resulting in an increase in the discharge reaction area. Dynamics of ignitions and propagation of the gliding arc discharge are revealed with a high-speed camera imaging synchronized with the applied pulsed voltage. The result shows that a shortcut discharge with a different generation mechanism appears. It is found that formation of a shortcut current path between the two legs of the stretched arc discharge occurs, resulting in a new ignited arc discharge. Thus, the pulsed gliding arc discharge can be repeatedly generated without a reignition at the shortest gap between the electrodes. The probability of the occurrence of the shortcut discharge increases as the repetition frequency of the pulsed voltage increases. Additionally, measurements of optical emission spectra of the gliding arc discharge show the presence of excited N ₂ , OH, and NH radicals. The OH emission dominates in the gliding arc discharge with the shortcut events. It can be concluded that the repetition frequency of the applied pulsed voltage becomes the control knob for chemical reactions in future industrial applications.