The plasma discharge unit was designed based on the shock tube experiment system

and the plasma discharge VA characteristic curve was measured. The auto ignition delay

ignition delay with continuous discharge and ignition delay after the discharge shut down were measured. The chemical reaction path in the methane ignition process was analyzed. The results showed that the plasma discharge voltage and current did not present the same change trend. The gas resistance changed continuously in the discharge process. Little discharge energy (less than 4J) can effectively reduce the methane ignition delay. The particles produced during the discharge could reduce the methane ignition delay in a certain degree after the power was shut down. The influence mechanism of plasma assisted methane ignition under the low or high ignition temperature condition was basically the same. The effects of continuous discharge were more apparent to reduce the methane ignition delay time when the ignition temperature was relatively low (less than 1000K) or high (greater than 1600K). The methane ignition delay could be shortened in an order of magnitude or more than one order of magnitude. It was a result of coupling effect of ignition temperature and plasma concentration act to the methane ignition delay.