Early Stage of Bubble Dynamics via Electrical Explosion in Water

Underwater discharge is an indispensable method to simulate underwater explosions, and it has received more and more attention in recent years. In this paper, the electrical explosion (a kind of pulsed discharge) of copper/aluminum wires connected in parallel in water was used as the research object. Electrical parameter diagnostics in combination with high-speed shadow photography were adopted to study the spatiotemporal evolution behavior of explosion products (plasma) bubbles. Experiment results indicated that after the electric explosion (phase explosion) occurred, the shock wave and ionization process proceed successively. Then the high-impedance warm dense matter promotes the energy deposition and expansion of the explosion products. After the discharge finished, the ionized metallic gas continued glowing for a period of time. time. It was also observed that clusters of protrusions on the explosion product-water interface, which might be related to local explosions/discharges. The copper wire explosion product interface was smooth and explicit, while the aluminum wire had a flocculent boundary layer. In addition, the Richmyer-Meshkov instability caused by the shock wave between the metal double wires was not obvious.