钨电极的水中脉冲放电过程数值计算研究

Numerical Calculation Research on Pulse Discharge Process of Tungsten Electrode in Water

建立了针-针钨电极在脉冲电压作用下击穿放电的流体数学模型,利用COMSOL软件仿真水中脉冲放电过程,研究了不同放电条件下钨电极击穿过程中流注的形貌发展、带电粒子的密度和流柱的迁移速度。仿真结果表明:在针-针电极间距为3mm,脉冲电压幅值为11~15kV时,电子密度最大值均在1023·m^(-3)数量级上,随着电压幅值的增大,等离子体中的电子密度峰值也会增大,且流注的发展速度加快;增大钨电极的电极间隙时,流柱发展所用时间变长,但流柱的发展速度也会变快。通过实验中光谱仪的测量数据计算得到的电子密度也处于1023·m^(-3)数量级上,验证了仿真结果的合理性。电子密度的大小会影响放电通道中温度、电场强度和自由基反应速率等物理量,所以电子密度的数值计算有着重要意义。

In this paper,a fluid mathematical model of the needle-needle tungsten electrode breakdown discharge under the action of pulse voltage is established,and the COMSOL software is used to simulate the pulse discharge process in water,and the morphology development of the streamer,the density of the charged particles and the migration velocity of the streamer during the breakdown of the tungsten electrode under different discharge conditions are studied.The density and the migration velocity of the stream column.The simulation results show that when the needle-to-needle electrode spacing is 3mm and the pulse voltage amplitude is 11-15kV,the maximum electron density is on the order of 1023·m^(-3).With the increase of the voltage amplitude,the electrons in the plasma The peak density will also increase,and the development speed of the streamer will be accelerated;when the electrode gap of the tungsten electrode is increased,the time for the development of the streamer will be longer,but the development speed of the streamer will also be faster.The electron density calculated by the measurement data of the spectrometer in the experiment is also on the order of 1023·m^(-3),which verifies the rationality of the simulation results.The magnitude of the electron density will affect physical quantities such as temperature,electric field strength and free radical reaction rate in the discharge channel,so the numerical calculation of the electron density is of great significance.