金属桥箔电爆炸驱动飞片过程数值模拟研究

Numerical Simulation of Metal Bridge Foil Electric Explosion Driving Flyer

为研究金属桥箔电爆炸等离子体驱动飞片全过程中飞片的性能特征和影响规律,建立了金属桥箔电爆炸驱动飞片全过程的多相流数值计算模型,并进行了数值模拟计算.计算中,利用了相变分数描述金属桥箔由固相到等离子体相的相态转变,采用了考虑粒子数目变化及粒子间库仑作用的高温高压等离子体状态方程描述电爆炸等离子体的形成和运动行为,采用了动网格模型描述飞片的运动.将计算结果与实验结果进行对比分析,计算得到的飞片速度值与实验值的误差小于5%,表明计算模型的准确性较好.基于该计算模型,对总面积相同的双体阵列桥箔和单体桥箔电爆炸等离子体驱动飞片过程进行了数值模拟,计算结果表明,由于阵列桥箔电爆炸过程中等离子体和冲击波的叠加汇聚作用,提高了能量转化效率,使得等离子体及冲击波流场对飞片的驱动力增加,从而提高了飞片的速度.等离子体流场对飞片表面的烧蚀厚度约为0.1μm,飞片的完整性较好.

In order to study the performance characteristics and influence laws of the flyer driven by metal bridge foil electric explosion plasmas,a numerical calculation model of multiphase flow in the whole process of the flyer driven by metal bridge foil electric explosion plasmas was established,and numerical simulation was carried out.The phase transition from solid phase to plasma phase was described by phase transition fraction.The formation and motion behavior of electric explosion plasma was described by the state equation of high temperature and pressure plasma which took into account particle number and coulomb interaction between particles.The motion of flyer was described by dynamic grid model.The calculated results were compared with the experimental results,and the error between the calculated and experimental values was less than 5%,indicating that the accuracy of the calculation model is good.Based on this model,numerical simulations were carried out on the process of the electric explosion plasma driving flyer of the double-body array bridge foil and the single bridge foil with the same total area.Calculation results show that the superposition and convergence of plasma and shock wave in the electric explosion process of the double-body array bridge foil improves energy conversion efficiency,which increases the driving force of plasma and shock wave flow field on the flyer,thus increasing the speed of flyer.The ablation thickness of the surface of flyer is about 0.1μm,and the integrity of flyer is good.