在6 000 V的放电电压条件下,采用直径为10 mm的同轴圆筒电极模型,研究了当量比变化对电子密度和活性粒子浓度变化的影响.结果表明,电子密度随距阴极距离的减小而逐渐增加,在距离阴极附近较小位置时(0.05~0.4 mm)电子密度的最大值呈现先增大后减小的趋势,并在0.1 mm位置达到峰值.放电极大地提高了活性粒子H、O3、CH3和NO的摩尔浓度,随着当量比的降低,各活性粒子的摩尔分数略有减少,但即使在最低的当量比条件Φ=0.4时仍能产生较多的活性粒子,随当量比的变化电子密度并无显著影响.%Numerical simulation of dielectric barrier discharge of CH4/air mixture was carried out by employing a coaxial cylindrical electrode with diameter of 10 mm under the condition of discharge voltage of 6 000 V.The influences of equivalence ratio on electron density and active particle concentration were analyzed.The results show that electron density increased with the shortening of the distance from the cathode.For a small scope near the cathode(0.05~0.4mm),the maximum value of electron density increased up to 0.1mm,and then decreased.The discharge greatly increased the molar concentration of NO,O3,CH3 and H.With reduction of equivalence ratio,molar fraction of the active particles decreased slightly,but still produced a plenty of active particles at the lowest equivalence ratio Φ=0.4.The electron density had no significant effect with the change of equivalence ratio conditions.
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