不同介质条件下大气压脉冲放电特性的数值仿真研究

Numerical Study on Discharge Characteristics of Atmospheric Dielectric Barrier Discharges Driven by Pulsed Voltages with Various Barriers

大气压脉冲介质阻挡放电由于其独特的放电特性引起了人们极大的关注。为了深入理解外加放电参数对脉冲放电特性的影响,通过理论分析与数值模拟的方法,基于大气压等离子体的一维流体描述,定性研究了在给定电压波形的情况下介质类型、介质厚度、气体间隙、放电频率对大气压脉冲介质阻挡放电特性的影响,并与相关的实验结果进行了对比。仿真结果表明:在其他参数不变的情况下,随着介电常数的增加,放电电流与最大气体电压均变大,同时输入能量增加并可以输送更多的电荷;随着介质厚度的增加,放电电流幅值降低,同时脉宽变窄,输运的电荷量降低;随着气隙距离的增大,放电电流密度逐渐下降,击穿时刻出现延迟;随着频率的增加,放电电流降低,同时需要输入能量增加。本文的研究将对大气压脉冲放电应用中放电参数的选择提供一定的理论依据。

Atmospheric dielectric barrier discharges driven by pulsed voltage have unique discharge characteristics. To further understanding how the charge characteristics are determined by discharge settings, we qualitatively studied the discharge driven by given voltage pulses in different settings including various barrier dielectrics, barrier thickness, elec- trode spacing, and pulse frequency, based on numerical simulations and theoretical analyses using a one-dimensional fluid model. The results were compared to experimental data accordingly. It is concluded that, with the other settings being fixed, using barrier dielectrics with higher dielectric constant will increase the discharge current and peak gas voltage, meanwhile,the energy input is increased and more charge is transferred. Increasing the thickness of dielectric barrier will decrease the density and pulse width of discharge current. Lengthening the electrode gap will also decrease the current density, while it also brings ignition delay to the gap breakdown. The increase of pulse frequency will decrease current density and breakdown voltage, but more power is required to couple into the discharge region. The results can bc used as a theoretical foundation for parameter selections of atmospheric plasmas driven by pulsed voltages.