Study of the shock waves characteristics generated by underwater electrical wire explosion

A model is proposed to simulate the generation and propagation of the shock wave (SW) produced by underwater electrical wire explosion in microsecond timescale, with the assumption that the exploding wire instantly turns into uniform discharge plasma channel (DPC) after the onset of explosion. To describe the interaction between the DPC and the surrounding water medium, the initial temperature of DPC is obtained by fitting calculated pressures with experimental data, and the injected energy of DPC is provided by the measured discharge current after wire explosion. To attenuate the high frequency oscillations generated by the discretization, the method with the double artificial viscosity parameters is proposed to calculate the SW propagation characteristics, and the input parameter is the above-calculated DPC boundary trajectory. Based on the proposed model, the DPC and SW properties of an underwater copper wire explosion are analyzed. The results show that the estimated initial temperature of DPC is about 15 000 K, the attenuation of peak pressure can be characterized by a law of the radial propagation distance r to the power of -0.74, and the efficiency transferred from stored electrical energy to the exploding wire and the generated water flow are ∼71.5% and ∼10%, respectively.