Effect of Deposition Energy on Underwater Electrical Wire Explosion

Abstract

Underwater electrical wire explosion (UEWE) of the copper wire of 0.3 mm in diameter and 50 mm in length at high and low initial stored energies was compared. For this wire, the completely vaporization energy is 194 J. While the UEWE at high initial stored energy of 961 J show a good reproducibility, the shock waves generated by UEWE at low initial stored energy of 120 J have a poor reproducibility that is attributed to the partial vaporization of the exploding wire. As the initial stored energy was gradually increased from 110 to 1000 J, the deposition energy in the exploding wire was increased from 92 to 246 J. When the deposition energy is higher than the complete vaporization energy of the wire, the relative error in the shock wave is significantly reduced to 4%. The effect of the wire diameter on the UEWEs was investigated by keeping the initial stored energy at 120 J. It was observed that there exist two discharge modes, the mode of the cutting-off current with a partial vaporization for the wires of a diameter smaller than 0.5 mm and the mode of the continuous discharge with no vaporization for the wire of 0.5 mm in diameter. It was found that a partial vaporization of a vaporization rate as low as 6% is enough to generate the shock wave and the amplitude of the shock wave is determined by the vaporized mass of the wire. The more the vaporized mass, the higher is the shock wave.