Research on the characteristics of atmospheric air dielectric barrier discharge under different square wave pulse polarities

Energy efficiency limits the application of atmospheric pressure dielectric barrier discharge (DBD), such as air purification, water treatment and material surface modification. This article focuses on the electrical and optical effects of the DBD under three square wave pulses polarities-positive, negative and bipolar. The result shows that under the same voltage with the quartz glass medium, the discharge efficiency of bipolar polarity pulse is the highest due to the influence of deposited charge. With the increase of air gap distance from 0.5 to 1.5 mm, average power consumed by the discharge air gap and discharge efficiency decrease obviously under alumina, and increase, and then decrease under quartz glass and polymethyl methacrylate (PMMA). Through spectrum diagnosis, in the quartz glass medium, the vibration temperature is the highest under negative polarity pulse excitation. Under bipolar pulse, the vibration temperature does not change significantly with the change of air gap distance. For the three dielectric materials of quartz glass, alumina and PMMA, the molecular vibration temperature is the highest under the quartz glass medium with the same voltage. When the gap spacing, pulse polarity or dielectric material are changed, the rotational temperature does not change significantly.