阵列桥箔电爆炸过程数值模拟

为提高金属桥箔电爆炸的能量利用效率，增加桥箔电爆炸等离子体作用范围，设计了金属阵列桥箔结构，采用有限元流体动力学方法对金属阵列桥箔电爆炸过程进行了数值模拟.利用相变分数和考虑电离度、粒子数目变化及粒子间库仑作用的等离子体状态方程，实现了金属导体在脉冲大电流作用下电爆炸产生等离子体及冲击波的数值模拟计算.对比分析了阵列桥箔在有加速膛通道和无加速膛自由场两种情况下的电爆炸等离子体流场特征及演化规律.计算结果表明，两种情况下等离子体束在叠加汇聚区压力较高，在无加速膛自由场中电爆炸初始冲击波速度和等离子体射流传播速度都较高；在有加速膛情况下，由于气体粘性作用，管壁附近存在一个高压低速边界层，加速膛通道内冲击结构较为复杂.

Numerical Simulation of Array Bridge Foil Electrical Exploding

In order to improve the energy utilization efficiency of the metal bridge foil and increase the function range of plasma beam, metal array bridge foils were designed in the present paper. The processes of array bridge foil electrical exploding were simulated based on the finite element fluid dynamics method. By using the phase change fraction and the plasma state equation considering the degree of ionization, the number of particles, and the Coulomb interaction between particles, the numerical simulation of the plasma and shock wave generated by the electric explosion of a metallic conductor under the action of a pulsed large current is realized. The evolution laws and characteristics of the plasma flow field were analyzed comparatively, with considering the electrical exploding in the acceleration chamber channel and the semi-free field without acceleration chamber. The calculation results show that the pressure of plasma beam superimposed area is high. The initial shock wave velocity and the plasma jet velocity of the electric explosion without the acceleration chamber are higher than that in acceleration chamber. In the case of having acceleration chamber, there exists a high pressure and low velocity boundary layer near the pipe wall due to the viscous effect of gas. The shock wave structure in the acceleration chamber is more complicated.