大气压Ar/NH_3介质阻挡辉光放电的仿真研究  

Modelling study of dielectric barrier glow discharge in Ar/NH_3 mixture at atmospheric pressure

作　　者：张增辉[1] 张冠军[1] 邵先军[1] 常正实[1] 彭兆裕[1] 许昊[1] 

机构地区：[1]西安交通大学电气工程学院,电力设备电气绝缘国家重点实验室,西安710049

出　　处：《物理学报》2012年第24期392-402,共11页Acta Physica Sinica

基　　金：国家杰出青年科学基金(批准号:51125029)资助的课题~~

摘　　要：为了研究大气压下氩气(Ar)中掺杂氨气(NH3)的Ar/NH3介质阻挡辉光放电的放电机理,通过建立一个多粒子的自洽耦合流体模型,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,以及带电粒子、中性粒子与空间电场强度的时空分布.仿真计算结果表明:气体间隙的周期击穿过程主要由气隙电压控制,并受气隙两侧介质极板上积聚的表面电荷的影响.气隙间带电粒子密度和电场强度的时空分布表明本文的放电过程存在阴极位降区、负辉区、法拉第暗区、等离子体正柱区等辉光放电的典型区域,放电模式为大气压辉光放电.在Ar/NH3等离子体中,主要的正离子为NH+3,其次为Ar+2,主要的负离子为NH-2;NH3分解产生的主要的激发态分子为NH,NH2和N2H3,而最终的稳态产物主要是N2和H2.In order to investigate the mechanism of dielectric barrier glow discharge in Ar/NH3 mixture at atmospheric pressure, a multiple particles self-consistent coupled fluid model is proposed. And the finite-element method is used in the numerical calculation model, so the periodically varying waveforms of gas voltage, dielectric surface charge density and discharge current density are investigated. The spatial and temporal distributions of charged and neutral particles density and space electrical field strength are also obtained. The simulation results show that the periodic breakdown process of the gas gap is controlled by the gas voltage, and affected by dielectric surface charges. The spatiotemporal distributions of charged particle density and electrical field strength show that the discharge under conditions considered in this model is a typical atmospheric pressure glow discharge, and that in the discharge process there exist an obvious cathode fall region, a negative glow region, a Faraday dark space, and a positive column region. In the Ar/NH3 plasma, the dominant positive ions are NH＋, and the next ions are Ar＋; the dominant negative ions are NH2-; the main radical molecule products of ammonia decomposition are NH, NH2, and N2H3, but the main final stable products are N2 and H2.

关 键 词：介质阻挡放电 大气压辉光放电 低温等离子体 流体模型 

分 类 号：O461.21[理学—电子物理学]