水中负极性灌木状放电特性研究

Study on Characteristics of Negative Bushy Discharges in Water

该文研究不同外施电压下水中灌木状流注的形貌演化过程、间歇发光特性和分叉机制。实验结果表明,流注形态演化与放电注入能量密切相关。随外施电压增加,流注气相通道阴影面积迅速上升,形态从双分支结构逐渐过渡至多分支结构。灌木状流注在发展过程中呈现间歇发光特性,外施电压增加导致平均发光间隔显著降低。该现象取决于流注通道气—液界面的电荷沉积与消散过程。流注表面电荷的不均匀分布特性及外施场强共同决定了灌木状流注的分叉行为,实验观测与理论分析表明流注通道表面突起形成与分支通道发展在流注半径较小时更为明显,且随外施场强增大而不断加剧。

This paper concentrated on the morphology evolution, intermittent illuminance and branching of bushy streamers under various applied voltages. Experimental results showed that the evolution of streamer morphology was closely related with discharge energy. The shadow area of streamers rapidly grew with an increase in the applied voltage and streamers gradually evolve from the double-branch to multi-branch structure. The intermittent illuminance of streamer was observed and the average interval of illuminance decreased remarkably with the rise of applied voltages. This phenomenon is strongly affected by the deposition and dissipation of charges at gas/liquid surface of streamers. Streamer branching was determined by the uneven distribution of deposited charges and electrostatic force at gas/liquid surface. The experimental observation and theoretical calculations show that the protrusions and branching at channel surface become more apparent when streamers own smaller radii and grow rapidly with the rise of applied electric field.