Study on Breakdown Process of High -Voltage Pulse Discharge under Water based on Equivalence Theory and Numerical Simulation.

The breakdown process of high-voltage pulse discharge under water involves rapid changes in the plasma channel, which are influenced by various factors, such as time, electric field, and thermal field. Accurately measuring the plasma channel is challenging due to technological limitations. This study proposed the theory of equivalence and equivalent numerical simulation for underwater pulsed discharge to understand the breakdown process and the role of the plasma channel in high-voltage pulse discharge under water. It established the equivalence theory and numerical simulation of the discharge breakdown process by considering the delay characteristics of discharge breakdown and the plasma channel model. The plasma channel was described intuitively and quantitatively, providing a concise and effective analysis of the complex breakdown process. Results indicate that (1) the breakdown channel undergoes an initial plasma channel stage accompanied by heating effects, which then transforms into an arc channel, leading to breakdown and detonation. (2) The equivalent resistance of the plasma channel is approximately 10 Ω, and the equivalent radius of the initial channel is around 0.1 μm. Breakdown is difficult to achieve when the electrode spacing is 0.5 cm and the charging voltage Um is below 5.5 kV, with an estimated minimum charging voltage of approximately 6 kV required for breakdown. (3) Equivalence theory enables effective quantification of the equivalent radius and equivalent resistance in the breakdown process, providing a representative measure of breakdown process stability. It proves to be an effective method for monitoring the operation of discharge equipment in practical engineering. The study provides a reliable reference for assessing the breakdown process of underwater high-voltage pulse discharge and monitoring the performance of pulse discharge equipment. [ABSTRACT FROM AUTHOR]