大气压氩气介质阻挡辉光放电的一维仿真研究

为了研究氩气(Ar)中介质阻挡大气压辉光放电(APGD)的放电机理, 通过建立一个一维的多粒子自洽耦合流体模型, 采用有限元方法进行数值计算, 得到了气体间隙压降、介质表面电荷密度、放电电流密度随时间的周期变化波形, 以及电子、离子、亚稳态粒子密度和空间电场强度的时空分布. 仿真计算结果表明：介质表面积聚的电荷对于放电的过程的起始及熄灭具有重要作用；当增大外施电压时, 放电击穿时刻提前, 放电电流密度和介质表面电荷密度峰值增大, 表明放电过程更加剧烈；随着阻挡介质相对介电常数的增大, 放电电流密度也随之增大. 各粒子密度及电场的时空分布表明放电过程在外施电压半个周期中只有一次放电, 且存在明显的阴极位降区、负辉区、等离子体正柱区等辉光放电的典型区域, 为大气压辉光放电(APGD).

One-dimensional simulation of dielectric barrier glow discharge in atmospheric pressure Ar

In order to investigate the mechanism of dielectric barrier atmospheric pressure glow discharge(APGD) in Ar, an one-dimensional multiple particle self-consistent coupled fluid model is proposed. And the finite-element method (FEM) is used in the numerical calculation model, so the periodic evolvement waveforms of gas voltage, barrier surface charge density and discharge current density are investigated. The spatio temporal distributions of electrons, ions, metastable particles density and space electrical field are also obtained. The simulation results show that the charges accumulated on the barrier dielectric surface play an important role in ignition and extinguishment of the discharge. With the increase of applied voltage amplitude, the DBD breakdown occurs ahead of time, and discharge current density and the surface charge density increase gradually, which indicate that the discharge process becomes fierce. Furthermore, with the increase of relative permittivity of dielectric material, the discharge current density also gradually increases. The spatio temporal distributions of the particles density and the space electrical field show that the DBD breakdown occurs every half the AC period and the discharge under conditions considered in this model is a typical atmospheric pressure glow discharge(APGD), having an obvious cathode fall region, a negative glow region, and a positive column region.