沿面型介质阻挡放电的数值仿真计算

Numerical Simulation of Surface Dielectric Barrier Discharge

沿面型介质阻挡放电因较平行板介质阻挡放电能产生均匀的较大面积等离子体层和在流动控制等新技术中的突出应用而得到学术界和应用界的广泛关注。为更好地研究和揭示沿面型介质阻挡放电的放电机理与演化规律,利用Comsol软件的等离子体模块对大气压空气中该放电进行二维数值模拟。考虑空气放电时O2-、N2-、O2+、电子等8种粒子及16种放电粒子化学反应,得到了放电过程中粒子浓度变化过程与放电空间的电场分布。分析讨论放电起始阶段电荷的运动情况后表明,电子在起始阶段主要受电场控制以漂移运动为主,其后在扩散和漂移的共同作用下分布范围不断扩大。验证分析放电的不对称性并与实验结果相对照后,指出正是由于表面电荷的积累导致了放电的不对称性。

Compared with the parallel-plate dielectric barrier discharge, surface dielectric barrier discharge （SDBD） can produce uniform plasma layer with a larger area, and it has also been mainly applied in such new technologies as the flow control, all of that have drawn a wide attention from the academia and the industry. In order to better research the discharge mechanism and the regularity of evolution of SDBD, we performed the two-dimensional numerical simulation of SDBD in the air with the plasma module of Comsol. In the process of air discharge, considering the chemical reaction of 8 kinds of particles, such as O2-, N2- , and 02＋ , and 16 discharge chemical reactions, we got the change process of particle concentration and the electric-field distribution in the discharge space. By analyzing and discussing the movement of electric charge in the initial phase, we find that, electron, mainly controlled by the electric field in the initial stage, will do drift motions, then its scope of distribution will be expanded which is affected by both diffusion and drift motions. Moreover, the asymmetry of discharge is analyzed and verified, and it is pointed out that the accumulation of charge on the surface leads to the asymmetry of discharge.