大气压空气介质阻挡放电的数值模拟

Numerical Simulation of Atmospheric Air Dielectric Barrier Discharge

常压介质阻挡放电(DBD)是等离子灭菌和废气处理应用中形成等离子体的主要方法。为了理解空气放电产生等离子体的基本过程,建立了包含20种成分和75种化学反应过程的多组分自洽一维流体模型。通过对同轴圆柱介质阻挡放电进行数值模拟,研究频率为10 kHz、峰值电压为20 kV的正弦电压驱动的常压空气介质阻挡放电的基本特性。结果表明:在一个正弦周期内将有两次不对称的电流峰;电流峰期间电子、电场与空间电荷之间以流注放电的形式变化;等离子体在正负电流期间的电子密度和电子温度分别可达(1～3)×10^(19)/m3和7～9 eV;放电过程中主要活性粒子为N、O、O_2(a^1△_g),主要的带电粒子为电子、O^+_4、O^-_2与O^-。

Dielectric barrier discharge（DBD） under atmospheric pressure is a main type of plasma generation method for applications of sterilization and exhaust treatment. In order to understand the generated process of plasma by air discharge,we established a self-consistent one-dimensional fluid model with 20 components and 75 chemical reactions for numerical simulation of the coaxial cylindrical DBD.Then the basic characteristics of DBD were studied under atmospheric pressure driven by 10 kHz sinusoidal with peak voltage of 20 kV. The results show that there are two asymmetric current peaks in one voltage cycle. During the current peaks, the electrons, electric field and space charge changes in the form of steamer discharge; electron density and electron temperature of the plasma are up to（1-3） X10^19/m^3 and 7-9 eV respectively. The main active particles in the discharge process are N, O and O2（a^1△g） and the main charge particles in the discharge process are electron, O^＋4, O^-2 and O^-.