水电导率对水下微秒脉冲流光放电形态的影响  

Effect of water conductivity on underwater microsecond pulsed streamer discharge type

作　　者：李霄 温小琼[1] 杨元天 LI Xiao;WEN Xiaoqiong;YANG Yuantian(School of Physics,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学物理学院,大连116024

出　　处：《物理学报》2025年第5期137-146,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11635004,12375248)资助的课题.

摘　　要：水下流光放电在降解水中有机污染物、改良农作物种子等方面有良好的应用前景,其放电形态对实际应用效果有重要影响.本文利用四分幅超高速相机观测了不同水电导率、外加电压条件下水下微秒脉冲流光放电过程,发现在高水电导率条件下存在两种不同的放电形态:扇形丝丛和单根长丝.在本文研究范围内水电导率800μS/cm是两种形态出现率的分界点:水电导率小于800μS/cm时,单根长丝形态的出现率为100%;水电导率大于800μS/cm时,随着水电导率的增大,单根长丝形态的出现率降低,扇形丝丛形态的出现率增大;水电导率大于1000μS/cm后,主导放电形态为扇形丝丛形态,随水电导率的增大反转两种放电形态的出现率所需的电压增大.扇形丝丛流光传播速度~1.7 km/s,单根长丝流光早期传播速度~25 km/s,后期传播速度下降至~0.8 km/s,水电导率和外加电压对两种形态的传播速度没有显著影响.扇形丝丛形态的放电延迟时间总是比单根长丝形态的大~8%,单脉冲注入能量比单根长丝形态的小~20%.Underwater streamer discharges have various potential applications in the fields of wastewater treatment,crop seed processing,etc.The underwater streamer discharge types have an important effect on the practical applications.In this work,the underwater microsecond pulsed streamer discharges are investigated by using an ultra-high-speed frame camera system at different water conductivities and applied voltages.It is found that there exist two different types of discharge under the same experimental conditions:the fan-shaped bush type and the long-single filament type.The water conductivity of 800μS/cm marks the boundary point for the occurrence rates of the two discharge types:when the water conductivity is less than 800μS/cm,the occurrence rate of the long-single filament type is 100%;when the water conductivity is larger than 800μS/cm,the occurrence rate of the long-single filament type decreases,but the occurrence rate of the fan-shaped bush type increases with water conductivity increasing.When the water conductivity is larger than 1000μS/cm,the dominant discharge type is the fan-shaped bush type,and the voltage required to reverse the appearance rates of the two discharge types increases as the water conductivity increases.The fan-shaped bush type streamer has a propagation velocity of~1.7 km/s,and the long-single filament streamer has a propagation velocity of~25 km/s in the early stage and a propagation velocity of~0.8 km/s in the later stage.Neither of water conductivity and applied voltage has significant influence on the propagation velocities of the two types of streamers.The time lag of the fan-shaped bush-type discharge is about 8%larger than that of the long-single filament-type discharge.The injection energy per pulse of the fan-shaped bush-type discharge is about 20%smaller than that of the single filament-type discharge.

关 键 词：水下微秒脉冲流光放电 水电导率 扇形丝丛形态 单根长丝形态 

分 类 号：TS1[轻工技术与工程—纺织科学与工程]