Observation of liquid-gas phase dynamics from pre-breakdown to postdischarge in a single-shot underwater pulsed discharge

In this study, Schlieren photography technique has been applied for the visualization of the pressure field of a single-shot underwater pulsed discharge. A needle-to-plane electrode configuration submerged in distilled water was used. The detailed time- and space-resolved observation of both streamers and pressure waves was performed. As a result, several phenomena, such as the phase change prior to the initiation of the discharge, primary and secondary streamers propagation, shock wave generation, and the bubble formation, were observed. From these observations, a scenario of multiple events from pre-breakdown to post-discharge was proposed.