Study on underwater subsonic electrical discharges: Streamer morphology and development

摘要

This paper focus on the streamer behaviors of underwater subsonic electrical discharges. The influence of applied voltage on the development mode and morphology of the underwater subsonic streamers is studied. The discussion on the development mechanism of the underwater subsonic streamer is given. Finally, the polarity effect on the underwater subsonic streamer morphology and development is analyzed. The results show that the positive streamers develop in two modes: bubble cluster mode (positive subsonic mode) at low applied voltage and tree-like streamer mode (positive supersonic mode) at high applied voltage. Meanwhile the negative streamers develop in tree-like streamer mode (negative subsonic mode) but with numerous filaments. The large discrepancy between mobility of ions and electrons is supposed to be the main cause of polarity effect.