Numerical Simulations for Design Optimization of Wire Array in Underwater Electrical Wire Explosion (UEWE)

How to enhance the shock wave (SW) generated by underwater electrical wire explosion (UEWE) is one of the core problems in dynamic high-pressure loading. In this article, numerical simulations were carried out using ANSYS/AUTODYN to visualize the convergence process of SWs and analyze the parametric influences on converging waves. Unlike the assumption regarding exploding wire as typical explosives, we assumed that the formation of SW originates from the instantaneous expansion of high-temperature metal gas/plasma. In order to validate the effectiveness of the simulation tool, numerical simulation was first conducted at experimental conditions in the literature, and the obtained simulation results exhibit good consistency. Then, cylindrical wire arrays and cylindrical split wire arrays (whose total cross section of all wires is constant) were studied at a fixed specific internal energy, simulation results show that: 1) the converging wave produced by cylindrical split wire array has smaller pressure amplitude than cylindrical wire array, but consumes much less energy and 2) the convergence effect can make up the shortage of rapid decay of SW induced by thin wire when the wire number is over 8. Besides, shrinking the wire array radius is a better way for enhancing the converging wave compared with pouring more energy into exploding wire. This article indicates that the numerical approach presented in this article can be used to rapidly assess the characteristics of converging wave for existing or when developing new wire array configurations.