针电极下大气压脉冲放电模式转换机制模拟研究

项目名称： 针电极下大气压脉冲放电模式转换机制模拟研究

项目编号： No.11505020

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 张佼

作者单位： 大连理工大学

项目金额： 23万元

中文摘要： 针-板（针-针）电极下的大气压脉冲放电在材料表面改性、污染物处理、杀菌消毒等方面具有广泛应用前景。国内外的实验研究表明在针电极下的大气压脉冲放电存在多种放电模式（电晕、辉光、火花等），通过改变放电系统的某些参数可以实现放电模式的转换。然而由于大气压脉冲放电实验诊断技术的限制，使得实验上很难给出宏观等离子体参数（电荷分布、电场分布等），以及各种放电模式更具体的特点和更精确的参数范围，因此需要借助数值模拟手段来实现对针电极下的大气压脉冲放电的深入研究。本项目将采用二维流体模型来自洽的求解连续性方程、动量方程、Poisson方程，并利用Ghost fluid method 处理针电极位型。模拟将给出各种放电模式的参数（脉冲电压、针电极半径、放电间隙等）范围，以及每种放电模式下的粒子密度、电场、温度等参数的时空演化情况，并分析其放电机制和放电特点，为进一步的实验研究及应用提供有力的科学依据。

中文关键词： 大气压脉冲放电；流体力学模拟；模式转换；针电极；数值模拟

英文摘要： There is growing interesting in atmospheric-pressure pulsed discharges with point-to-plane (or point-to-point) electrodes for various potential applications such as material surface modification, pollutant treatment, sterilization and disinfection, etc. Recently, experimental studies have reported several kinds of discharge modes including corona, glow, and spark in atmospheric-pressure pulsed discharge with point electrode, and by varying the discharge parameters the discharge mode would be transformed from one to another. However, due to the limitation of present experimental diagnose technology of atmospheric-pressure pulsed discharge, it is very difficult to obtain the macroscopic plasma parameters such as the spatiotemporal distributions of particle density and electric field as well as more precise discharge parameter range and more detailed discharge characteristics at different discharge modes. Hence it is necessary to further study the atmospheric-pressure pulsed discharges with point electrodes by the way of numerical simulation. In this project, a two-dimensional fluid model is developed to self-consistently solve the continuity equation, momentum equation, and Poisson’s equation to obtain the particle density and electric field. Electron and gas temperature is also calculated. Ghost fluid method is used to deal with the complex point electrode geometry. The dependence of different discharge modes on discharge parameters (such as applied voltage, pin curvature radius, discharge gap, etc.) is presented when the discharge system is stable. By analyzing the spatiotemporal evolutions of charge density, electric field, temperature and other parameters at different discharge modes, the discharge mechanism and characteristics will be investigated. Those results will provide a powerful scientific support not only for the further experimental study but also to meet the future application needs.

英文关键词： Atmospheric-pressure plused discharge;Fluid model;Mode transition;Point geometry electrode;Numerical simulation