Abstract:
Background Electrical wire explosion (EWE) is a rapid energy deposition and phase transition process driven by high-current pulsed discharges, with important applications in pulsed radiation sources, shock wave generation, material fabrication, and surface treatment. However, the extremely short duration and wide thermodynamic range of EWE make it difficult for experimental diagnostics to fully characterize the spatiotemporal evolution of the discharge channel. It is necessary to combine numerical simulations with experimental measurements for an in-depth investigation of the underlying physical mechanisms. Most existing two-dimensional models are custom-developed codes designed for specific problems, which restricts their applicability to broader engineering applications.
Purpose This study aims to develop a scalable numerical simulation framework for investigating the dynamic evolution of EWE processes and plasma channel characteristics.
Methods An explicit dynamics simulation platform is employed to establish a two-dimensional magnetohydrodynamic (MHD) model of EWE. The exploding wire is modeled using the arbitrary Lagrangian-Eulerian (ALE) method to accommodate large deformations, while the surrounding medium is described using the Eulerian formulation. The current density distribution is obtained by solving the circuit equation and the steady-state electric field equation, and the Joule heating and Lorentz force are incorporated into the governing equations as source terms, enabling a coupled solution of electromagnetic and hydrodynamic processes. A wide-range equation of state (EOS) and electrical conductivity data for metals are employed, enabling a self-consistent simulation of the entire process from room temperature to extreme thermodynamic states. Taking the electrical explosion of a copper wire in air as a case study, numerical simulations were conducted under various discharge conditions, and the formation and evolution of axially nonuniform structures driven by electrothermal instability (ETI) were simulated by introducing an initial density perturbation.
Results The calculated discharge waveforms, deposited energy, and channel expansion dynamics are in good agreement with experimental results, validating the reliability of the model. The results indicate that the initial perturbation induces local conductivity variations, which are progressively amplified by Joule heating feedback, leading to alternating high- and low-density axial striations with characteristic scales consistent with experimental observations.
Conclusions The proposed model provides a transferable numerical framework for studying EWE processes and products. By replacing material parameters, the model can be extended to different metals and geometrical configurations, including metal foils and wire arrays. It also provides a foundation for further incorporation of three-dimensional effects and more complex physical mechanisms in engineering applications.