Modeling of chemical reaction processes induced by an atmospheric-pressure streamer discharge in air

Streamer discharge is a fundamental process of atmospheric-pressure plasma, which produces high chemical reactivity field in the interelectrode space and on the material. The physicochemical processes occurred in streamer discharges is a key to understand the degree of the chemical reactivity and to control the atmospheric-pressure plasma for industrial applications. However, the streamer discharge is spatially steep and temporally fast phenomenon, it is difficult to measure the characteristics of the streamer experimentally. In this situation, the numerical simulation could be a powerful tool for the study. This paper presents the recent works for analyzing the physicochemical processes in atmospheric-pressure streamer discharges using simulations and experiments [1, 2]. For comparison, an axisymmetric single-filament streamer is generated in atmospheric-pressure air and compared with 2D simulation [2]. The propagation, emission intensity, shape, cathode current and ozone density of the single-filament streamer are compared with the results of the 2D simulation performed under conditions similar to those of the experiments. A marked difference between the experiments and simulation was the appearance of an intense streamer in the simulation. If the discharge starting voltage was decreased in the simulation, the intense streamer was significantly decreased but simultaneously the primary streamer velocity was decreased and deviated from the measured value. The simulated ozone density showed good agreement with that of the measurement except the ozone production in the intense streamer.