Effect of Subatmospheric Pressure on Deposited Energy for Electrical Wire Explosion in Air

Abstract

Pressure is an important factor for the effect of the medium in the process of the electrical explosion of wire in air. In this paper, the electrical explosions of copper and aluminum wires at different air pressures in the range of subatmospheric pressure were investigated with pulsed voltage in a submicrosecond time scale. Based on the measurements of the current and voltage in wire explosion with a current monitor and a high-voltage probe, respectively, the deposited energy in the stages of melting, liquid state, and vaporization was calculated by mathematical methods. The effect of air pressure on deposited energy in the three stages mentioned above was analyzed by experiments and calculation. The results show that the breakdown field strength varied with air pressure, and plays a vital role in energy deposition and the time of duration in the vaporization stage. In addition, the exothermic reaction of Al microparticles and surrounding air also has an important effect on the energy deposition in the vaporization stage. The deposited energy in the electrical explosion of copper and aluminum wire is higher at the higher air pressure, particularly after the beginning of vaporization.