爆炸箔起爆器发火阈值影响因素的数值模拟

Numerical Simulation of the Factors Affecting the Ignition Threshold of an Exploding Foil Initiator

为了研究由桥箔、飞片和加速膛所组成的换能组件对爆炸箔起爆器(EFI)发火性能的影响,达到降低发火阈值的目的,利用ANSYS/AUTODYN软件,模拟了桥箔驱动飞片起爆六硝基茋(HNS-Ⅳ)的过程。研究了桥箔厚度对飞片速度的影响,探究了桥区宽度、飞片材料(有机玻璃、陶瓷和聚酰亚胺)、飞片厚度和加速膛长度对EFI发火阈值的影响。结果表明,减小桥区宽度有利于降低爆炸箔起爆器的发火阈值。在输入电压相同的条件下,2μm厚度的桥箔驱动飞片速度最大;爆炸箔起爆器发火电压随着飞片厚度的增加先降低后增大,当厚度为10μm时发火电压最低;相比于0.225 mm、0.250 mm和0.275 mm加速膛,用0.125 mm加速膛时发火电压最低,说明减小加速膛长度有利于降低爆炸箔起爆器的发火阈值;在加速膛孔径确定的情况下,"无限型"加速膛发火电压低于"有限型"加速膛。聚酰亚胺力学性能好、发火电压低、撞击动能小,优于其它两种材料(有机玻璃和陶瓷)。

To study the influence of the transducer component composed of bridge foil,flyer and accelerating chamber on the exploding foil initiator( EFI) ignition performance and achieve the goal of reducing the ignition threshold,ANSYS/AUTODYN software was used to simulate the process that bridge foil driven flyer to detonate HNS-Ⅳ. The influence of bridge foil thickness on flyer speed was studied,and the influences of bridge area width,flyer material( organic glass,ceramic and polyimide),flyer thickness and accelerating chamber length on EFI ignition threshold were investigated. Results show that reducing the width of bridge area is helpful to reduce the ignition threshold of exploding foil initiator. Under the same input voltage,the speed of flyer driven by bridge foil with thickness of 2 μm is maximum. The ignition voltage of exploding foil initiator decreases firstly and then increases with the increase of flyer thickness,and the ignition voltage is lowest when the thickness is 10 μm. Compared with 0.225 mm,0.250 mm and 0.275 mm accelerating chamber,ignition voltage of 0.125 mm one is lowest,so reducing the acceleration chamber length is beneficial for reducing ignition threshold of exploding foil initiator. Under the condition of determinig the accelerating bore aperture,"infinite"accelerating chamber is better than"finite"accelerating chamber for reducing firing voltage of EFI. Polyimide has better mechanical properties,lower ignition voltage and lower kinetic energy compared with other two materials( organic glass and ceramic).