空气辉光放电暂态空间电荷机理仿真分析与验证  

Numerical Simulation of Transient Space Charge Distribution of Direct Current Glow Discharge in Air with Experimental Validation

作　　者：刘兴华[1,2] 陈静[1] 孙学锋[1] 陈玉锋 郭志红 季素云 

机构地区：[1]国网山东省电力公司淄博供电公司,淄博255000 [2]国网山东省电力公司电力科学研究院,济南250002

出　　处：《高电压技术》2015年第9期2916-2924,共9页High Voltage Engineering

基　　金：国家重点基础研究发展计划项目(973计划)(2011CB209401)~~

摘　　要：为研究空气辉光放电暂态空间电荷的产生机理,提出了基于流体–化学反应的空气放电2维混合数值模型,并采用仿真模拟及实验验证方法获取在空气放电过程中空间电荷的产生机理及空间动态分布。在模型中,空气放电粒子输运过程采用流体动力学模型处理;粒子之间的反应过程采用化学反应模型处理,共包括12种粒子和27种化学反应过程。通过仿真及实验数据发现,放电电压–电流特性、电子温度空间分布的仿真数据与实验测量数据相符。基于被验证的仿真模型发现,放电过程中N2的电子碰撞电离反应是电子产生的主要方式。N2+和O2+是放电过程中产生数密度最大的正离子,分别为1.1×1015 m-3、3×1014 m-3。N2+产生速率比O2+的产生速率快,分别为5.4×1022 m-3s-1、1.8×1022 m-3s-1,表明正离子和电子决定放电过程中等离子体的特性。随着放电时间延长,阴极的传导电流密度逐渐增加,但阳极的传导电流密度逐渐减少。提出的流体–化学混合模型可真实模拟空气辉光放电的暂态过程,对研究空气辉光放电的物理机理具有重要意义。In order to study the mechanism of transient space charge in air glow discharge, an improved two-dimensional plasma numerical model based on fluid-chemical reaction to simuiate air glow discharge is proposed. We used the model to conduct hybrid simulations, verified the results through experiments, and were able to obtain the dynamic mechanism and spatial distribution of the space charges. The model includes a plasma hydrodynamics model and a chemical model： the former one represents the particle transportation; the latter one represents the chemical reactions and it includes 12 species and 27 reactions. The results of simulation and the experiment including the discharge voltage-current characte- ristics and the spatial profiles of electron temperature are consistent with each other. With the validated model, we were able to conclude that the electron impact ionization reaction of N2 is the dominant way generating electrons. N2＋ and O2＋ are the dominant generated positive ions with number densities of 1.1× 1012 m-3 and 3 × 1014 m-3 respectively. The produc- tion rate of N2＋, 5.4×1022 m-3s-1, is greater than that of O2＋, 1.8×1022 m-3s-1, in the entire discharge process, and this indicates that positive ions and electrons determine the characteristics of discharge plasma. As time progresses, the con- ductive current density increases at the cathode, but decreases at the anode. It is proven that the presented plasma model is able to simulate the transient glow discharge in air accurately, which is of importance for under the physical mechanisms of low-pressure air glow discharge.

关 键 词：空气辉光放电 等离子体 混合模型 数值计算 空间电荷 实验验证 

分 类 号：O461.21[理学—电子物理学]