等离子体射流的流体力学模拟和输运系数计算

Hydrodynamic Simulation of Plasma Jet and Calculation of Transport Coefficient

对等离子体射流的流体力学进行了力学模拟,分析了场强与电极厚度及极间距离的关系;分析和探讨了在不同初始速度下,氦气流速、摩尔分布在轴向和径向的变化关系;分析和探讨了减弱场强对电离系数、He*的激发系数和N2(C^3Πu)的激发系数的影响.实验结果表明:场强的最大值与最小值都出现在阳极附近,为了增强阳极附近电场,可在一定程度上减小电极板的厚度d和减小两电极板之间的距离D2;在轴向上,随着z的增大,VHE逐渐衰减,氦气的摩尔分布逐渐降低;在径向上,随着r的增大VHE逐渐衰减,氦气的摩尔分布逐渐降低;随着电场减小,电离系数、He*的激发系数和N2(C^3Πu)的激发系数三者起初变化不太大,当电场继续减小时,三个系数下降的幅度变得越来越大,越来越明显.

The hydrodynamics of the plasma jet are simulated,the relationship between the field strength and the electrode thickness and the distance between the electrodes is analyzed.The changes of the helium flow rate and the molar distribution in the axial and radial directions at different initial velocities are analyzed and discussed.The influence of the weakened field strength on the ionization rate coefficient,the excitation rate coefficient of He * and the excitation rate coefficient of N 2 (C^ 3 Π u ) are analyzed and discussed.The experimental results show that the maximum and minimum values of the field strength appear in the vicinity of the anode.In order to enhance the electric field near the anode,the thickness d of the electrode plates can be reduced to a certain extent and the distance D 2 between the two electrode plates can be reduced.In the axial direction,with the increase of z,the VHE gradually decays and the molar distribution of helium decreases gradually.In the radial direction,as the r increases,the VHE gradually decays and the molar distribution of helium decreases.With the decrease of the electric field,the ionization rate coefficient,the excitation rate coefficient of He * and the excitation rate coefficient of N 2 (C^ 3 Π u ) do not change much at first.When the electric field continues to decrease,the amplitude of the three coefficients decreases getting bigger and bigger,more and more obvious.