一种新型等离子体通道的时变电阻模型

A new type of time-varying resistance model for plasma channel

为了准确分析水下放电过程中等离子体通道电阻的实际变化规律,进而更精确地计算通道沉积能量、电声转换效率等物理量,首先基于水下放电的等离子体通道电阻的“U”型曲线,构建了一种时变电阻函数,通过数据拟合的方式,确定了函数中的参数;然后,将时变电阻函数代入到以通道电流为变量的二阶变系数微分方程中,通过龙格-库塔数值算法得到通道电流的数值解;最后,使用改进的余弦相似度作为评价指标,比较了仿真电流与实测电流的差异。结果表明:仿真电流与实测电流吻合度高,验证了时变电阻模型的有效性。

In order to accurately analyze the actual variation law of plasma channel resistance during underwater discharge process,and to more precisely calculate physical quantities such as channel de-position energy and electro-acoustic conversion efficiency,a time-varying resistance function was constructed based on the "U" curve of the plasma channel resistance of underwater discharges,where the parameters were determined by data fitting.And then,the time-varying resistance function was substituted into the second-order variable coefficient differential equation with the channel current as the variable,and the numerical solution of the channel current was obtained by Runge-Kutta numerical algorithm.Lastly,the improved cosine similarity was used as the evaluation index to measure the difference between the simulation current and the measured current.The results show that the simulation current and the measured current are highly consistent,which verifies the effectiveness of the time-varying resistance model.