摘要
本文利用正弦交流电压激励液体电极放电系统,通过增大液体电导率(σ),发现放电从均匀模式过渡为斑图模式,且斑图模式中依次在液面观察到了齿轮、锯盘、离散点、单臂螺旋和同心圆环等结构.放电的电压电流波形表明放电仅发生在电压的负半周期(液体作瞬时阳极),气体击穿后放电电流迅速增大并很快达到峰值然后缓慢减小.对于均匀模式,放电电流的减小是单调的;但对于斑图模式,放电电流在减小过程中存在一段几乎不随时间变化的平台阶段.此外,随σ升高,峰值电流和平台电流均增大,且放电击穿时刻提前.利用增强型电荷耦合设备拍摄了均匀模式和斑图模式在液面附近的时间演化行为,发现不论何种放电模式最初液面上均产生的是均匀圆盘,而各种非均匀的斑图是产生在平台阶段.基于反应-扩散模型,通过改变离子强度与电流强度(对应变量m和l)对均匀模式和斑图模式进行了数值仿真,获得了实验对应的放电模式.此外,采集了液面附近放电的发射光谱,计算了与电子温度和电子密度相关的谱线强度比.通过对光谱进行拟合,获得了液面附近放电的气体温度和分子振动温度.研究发现这些等离子体参数随σ的增大(对应着放电模式的变化)而升高.
A liquid-electrode discharge system excited by an alternating-current sinusoidal voltage is employed to investigate the discharge modes with varying liquid conductivity(σ).The results indicate that with s increasing,the discharge transitions from the uniform mode to the pattern mode,which undergoes various selforganized patterns such as gear,circular saw,discrete spots,single-arm spiral,and concentric rings on the liquid surface.The voltage and current waveforms reveal that the discharge occurs only in the negative half-cycle of applied voltage(when the liquid acts as the instantaneous anode).After gas breakdown,the discharge current rises rapidly to a peak,and then slowly decreases.For the uniform mode,the current decreases monotonically.However,during the current decreasing in the pattern mode,there appears a plateau in which the current keeps almost invariant with time.As σ increases,the values of the peak current and the plateau increase,and the breakdown moment advances.In addition,fast photography achieved through an intensified charge-coupled device(ICCD)shows that regardless of the discharge mode,a uniform disk is initially generated on the liquid surface,and various non-uniform patterns are formed during the plateau stage.Based on the reaction-diffusion model,numerical simulations are carried out through changing ion strength and current strength,which are related to the variables m and l.The simulated discharge modes are well in line with those obtained in the experiments.Moreover,spectral line intensity ratios related to electron temperature and electron density are determined through the spectra emitted from the discharge near the liquid surface.By fitting the spectra,gas temperature and molecular vibration temperature are obtained,which show an increasing trend with σ increasing.
作者
李雪辰
张喜
朱国继
庞学霞
贾鹏英
孙辉
冉俊霞
李庆
李金懋
LI Xuechen;ZHANG Xi;ZHU Guoji;PANG Xuexia;JIA Pengying;SUN Hui;RAN Junxia;LI Qing;LI Jinmao(College of Physics Science and Technology,Heibei University,Baoding 071002,China;Hebei Key Laboratory of Photo-Electricity Information and Materials,Hebei University,Baoding 071002,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;Engineering Research Center of Zero-carbon Energy Buildings and Measurement Techniques,Ministry of Education,Baoding 071002,China)
出处
《物理学报》
北大核心
2025年第18期208-215,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:12375250,11875121,51977057,11805013)
河北省自然科学基金(批准号:A2022201036,A2023201012)
河北省光电信息材料实验室科研成果补贴基金(批准号:22567634H)
河北省杰出青年基金(批准号:A2012201045)
河北大学自然科学跨学科研究项目(批准号:DXK201908,DXK202011)
河北大学研究生创新基金(批准号:HBU2022bs004)资助的课题.
关键词
液体电极放电
自组织斑图
交流电压激励
时空演化
反应-扩散模型
liquid electrode discharge
self-organized patterns
alternating-current voltage driven
spatialtemporal evolution
reaction-diffusion model
