高频交流同轴圆柱介质阻挡放电特性实验研究

Experimental Study on Characteristics of Coaxial Cylinder Dielectric Barrier Discharge with High-frequency AC Actuation

同轴圆柱介质阻挡放电是非平衡等离子体实现强化燃烧的主要激励方式之一,掌握其基本放电特性对优化控制方案具有重要意义。为此,在高频交流激励模式下,开展了同轴圆柱介质阻挡放电特性的实验研究,通过改变气体种类、气体体积流量和电源参数,分析了不同因素对击穿电压、放电图像、Lissajous图形和放电功率的影响规律。结果表明:随着频率增加,击穿电压呈"V"型变化,期间存在最优频率使击穿电压最低,相比频率空气流量对击穿电压的影响并不明显。气体体积流量为0时,放电功率随频率、电压峰–峰值提高均线性增大,且提高电压的功率增长速率要明显快于频率;当有来流时,受气流对电荷分布的影响及其"吹除"作用,随频率和电压变化的功率曲线线性度均会降低,且随着气体体积流量增大,放电强度呈交替性增强减弱,使得消耗功率呈整体降低趋势的"M"型曲线变化。此外,甲烷放电时伴随有CH粒子产生,并且CH*自发辐射强度随电压提高呈线性增大。

Coaxial cylinder dielectric barrier discharge is one of the major approaches for plasma-assisted combustion,and it is important to reveal its basic discharge characteristics for optimizing control strategy.Consequently,with high-frequency AC actuation,the characteristics of coaxial cylinder dielectric barrier discharge,including breakdown voltage,discharge image,Lissajous figure,and discharge power,were experimentally studied by changing gas type,gas flow,and power output parameters.The results demonstrate that the curve of breakdown voltage is in a"V"shape with increase of frequency,during which an optimal frequency responding to the lowest breakdown voltage exists.Compared with the effect of frequency,the effect of gas flow on breakdown voltage is not obvious.When the gas flow equals 0,the power consumption increases linearly with frequency and voltage rising,respectively,and the power growth rate varies with voltage faster than with frequency.Moreover,when there is an incoming flow,with the effect of"blow off"and influence on charge distribution,the linearity of power curves varied with frequency and voltage will both decrease.And with increase of gas flow,the discharge intensity will be enhanced and weaken alternately,which results in a"M"-type curve with overall decreasing trend in power consumption.In addition,CH particles are generated under the discharge of methane,and the CH*emission intensity rises linearly with increase of voltage.