Similarity law and load optimization of underwater electrical explosion of wire array

Converging shock waves generated by underwater electrical wire array explosions can achieve extremely high pressure conditions in a relatively compact device, which has important value in the high-energy-density physics research. The energy conversion efficiency and the amplitude of shock waves depend on the matching relationship between wire arrays and pulse generators. Previous studies usually optimize the number of wires in the wire array by splitting the optimal single wire load. In this paper, we compared the underwater electrical explosion processes of wire arrays having the same total cross-sectional area but different splitting numbers based on one-dimensional magneto-hydrodynamic simulations. The simulated voltage and current waveforms showed that the electrical explosion cannot remain in the matched mode by splitting the optimal single wire. The thermodynamic evolution of exploding wires indicated that the primary reason for deviating from the matched electrical explosion is the differences in expansion rates. To explain these differences, a similarity law for the split wire arrays was introduced to find the conditions of keeping the same thermodynamic evolution. Finally, a novel optimization strategy for the wire array load was proposed based on this similarity theory.