Two-dimensional simulation of argon dielectric barrier discharge excited by a Gaussian voltage at atmospheric pressure

Abstract

A two-dimensional self-consistent fluid model was employed to investigate the spatiotemporal characteristics of discharges in atmospheric pressure argon (Ar) dielectric barrier discharge driven by a Gaussian voltage. The simulation results show that a discharge with multiple current pulses occurs each half-cycle in the gas gap. A transition from the Townsend mode to the glow mode is observed with the increasing applied voltage each half-cycle at a lower driving frequency (7.5 kHz). It is also found that the glow mode survives all the discharge phases at a higher driving frequency (12.5 kHz and 40 kHz). The change in the discharge mode with the driving frequency mainly lies in the fact that a lot of charged particles created in the discharge gap have no enough time to drift and diffuse around, and then these particles are assembled in the discharge space at higher frequency. Additionally, the spatial distributions of the electron density indicate that a center-advantage discharge is ignited at the driving frequencies of interest, resulting in the radial non-uniformity of discharge because of the edge effects. However, this overall non-uniformity is weakened with the driving frequency increased to 40 kHz, at which concentric ring patterns are observed. These distinct behaviors are mainly attributed to the fact that many charged particles generated are trapped in the gas gap and then accumulated to make the extension along the radial direction due to the charged particles transport and diffusion, and that the effective overlapping of a large number of avalanches induced by the increased “seed” electron density with the driving frequency. Meanwhile, the surface charged particles accumulated on the dielectric barriers are also shown to play a role in the formation of the discharge structure.

Pre-breakdown to stable phase and origin of multiple current pulses in argon dielectric barrier discharge

“…While during the onset phase the production peaks overlap with the peak of the applied voltage, when saturation is reached, the production peak is shifted from the voltage peak, due to the charge accumulation on the dielectric surfaces after the previous cycle. This result is consistent with previous works [38,43,63,64].…”

Numerical studies on the influences of gas temperature on atmospheric-pressure helium dielectric barrier discharge characteristics

“…Numerical simulations and experiments have been carried out to investigate homogeneous DBDs at least once [5][6][7][8]. These papers show that DBD mode depends on many factors, such as the working gas, driving frequency, electrode voltage, electrode gap and dielectric layer structure [5][6][7][8]. However, reports are relatively rare regarding the role of gas temperature in mode transition.…”

Streamer–surface interaction in an atmospheric pressure dielectric barrier discharge in argon

“…(Some figures may appear in colour only in the online journal) Dielectric barrier discharges (DBDs) are widely used as a source of low-temperature plasmas at atmospheric pressure [1][2][3]. Due to their importance, they are thoroughly investigated both experimentally [4][5][6][7][8][9][10][11][12] and by numerical modelling [13][14][15][16][17][18][19][20][21][22][23]. Depending on the operating conditions, DBDs appear either in a diffuse (Townsend or glow-like) mode or as a filamentary discharge, which is governed by the streamer mechanism [3,24].…”