中频域大气压介质阻挡放电中放电模式及其演化的数值模拟研究  

Numerical study on discharge modes in atmospheric dielectric barrier discharges and their transition excited by the medium frequencies

作　　者：张远涛[1] 刘雨 

机构地区：[1]山东大学电气工程学院,济南250061

出　　处：《中国科学：物理学、力学、天文学》2018年第2期63-73,共11页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:11375107和11675095);山东大学基本科研业务费(编号:2017JC017)资助项目

摘　　要：最近的实验研究表明,在300 kHz–3 MHz的中频域,大气压氦气介质阻挡放电存在两种放电模式,即Ω模式和混合模式.为了深入研究中频域的放电模式与低频域(25–100 kHz)辉光放电模式及高频域(5–15 MHz)α模式之间的关系,本文借助于一维流体模型,数值模拟了中频域放电的这两种放电模式,并与实验结果进行了比较.数值研究表明,在中频域Ω模式下,传导电流及功率相对较小,带电粒子主要产生在放电间隙的中部,密度较低,电子加热方式主要为放电区域中部的欧姆加热.而中频域的混合模式,既体现了低频域的辉光放电模式的特点,比如阴极附近有很高的离子密度,电子产生及欧姆加热的区域均在鞘层内部,同时也体现了高频域的α模式的特点,比如在放电间隙中部有密度很高的等离子体区,这些计算结果均与实验观测定性一致.同时,进一步在固定电压的条件下研究了放电模式随频率的变化,指出中频域的混合模式实际是低频域的辉光放电模式与高频域的α模式之间的过渡阶段,本研究将有助于深化人们对大气压气体放电中放电模式之间转化的认识.The recent experimental observation shows that in the medium frequency range （300 kHz-3 MHz）, there are two discharge modes, namely the 12 mode and hybrid mode. In this paper, a fluid model is explored to study the characteristics of these two discharge modes and their transitions. The numerical data indicate in the Ω mode the conduction current density is very low and the plasmas are mainly generated in the central region of gas gap, while the Ohmic heating takes place at the same region. For the hybrid mode, the ion density is very high in the sheath region, and the electrons are accelerated and produced in the sheath region, which are very similar to the characters of glow discharges in the low frequency region; meanwhile, a bulk plasma region with very high density is also formed in the center of gas gap, which is characterized by the a mode in the high frequency range. The mode transition among the glow discharge mode, hybrid mode and a mode is also investigated by varying the excitation frequency but with a fixed applied voltage. This simulation will deepen the understanding of mode transition in atmospheric discharges controlled by dielectric barriers for the whole excitation frequency range.

关 键 词：介质阻挡放电 中频域 Ω模式 混合模式 欧姆加热 流体模拟 

分 类 号：O461.2[理学—电子物理学]