摘要
长脉冲下的水中预击穿过程往往伴随着局部液体的扰动,而关于液相扰动的影响却鲜见报道。对超长脉冲条件下(脉宽大于100ms)的水中预击穿过程展开研究,深入探讨气泡、流注的发展模式及其差异,并阐释液相扰动对气泡、流注发展的影响机制。研究表明,气泡、流注在液相扰动中发展时具有更饱满光滑的形态,以及更快的传播速度。气泡、流注巨大的电导率差异导致了两者发展模式的不同:气泡的发展属于根部推动式,横、纵发展速度相当;流注的发展属于顶部牵引式,纵向发展速度远大于横向。进一步分析表明,扰动相中更高的液体温度与流动有利于气泡、流注的生长传播和形态稳定,同时扰动–静止相交界处形成的湍流会引发流注的分叉现象。
The pre-breakdown process in water under long pulse is usually accompanied by the disturbance of local liquid.However,the influence of liquid phase disturbance is rarely studied.In this paper,the pre-breakdown process in water under the ultra-long pulse condition(pulse width>100ms)was investigated.The development modes of bubble and streamer and their difference were discussed deeply.Finally,the influencing mechanism of liquid phase disturbance on the development of bubble and streamer was elucidated.The results show that the bubble and streamer developing in liquid phase disturbance have more rounded shapes and faster propagation speeds(compared with those in stationary phase).The huge conductivity discrepancy between bubble and streamer leads to the difference of their development modes.The bubble develops in bottom-up mode whose horizontal and vertical propagation speeds are nearly the same.Meanwhile,the streamer develops in top-down mode whose vertical propagation speed is much larger than horizontal propagation speed.Further analysis indicates that:higher liquid temperature and flow rate in the disturbance phase are beneficial to the development and morphological stability of bubble and streamer,and the turbulence at the junction of the disturbance and stationary phases will give rise to the branching behavior of streamer.
作者
李显东
何桦
肖天飞
熊鼎
李剑
LI Xiandong;HE Hua;XIAO Tianfei;XIONG Ding;LI Jian(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing 400044,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2022年第10期3846-3853,共8页
Proceedings of the CSEE
基金
国家自然科学基金(青年科学基金项目)(52007018)。
关键词
水中放电
预击穿过程
液相扰动
气泡
流注
分叉现象
underwater discharge
pre-breakdown process
liquid disturbance
bubble
streamer
branching behavior
