摘要
为了研究不同大气压氩气射流结构的放电特性以及气流速率、外施电压和电极结构对射流体长度的影响,设计了外表面双电极、外表面单电极和中心同轴电极3种不同结构的氩气等离子体射流装置,并结合气体动力学和静电场进行了分析。实验结果表明,随着气流速率的增加,射流管内的氩气流动状态会经历从最初的层流态到中间的过渡态再到最后的湍流态的过程,相应的射流体长度也随着气流速率的增加先增大后减小,并在雷诺数为2000～3000时达到最大值。总体上来说,在同一气流速率下,单电极结构的射流体长度略大于双电极结构,而中心电极结构的射流长度较短;中心电极结构的放电最为稳定,双电极次之,单电极最差。分析认为,射流体长度主要取决于流注崩头的高能电子,由于双电极和单电极结构的电场以轴向分量为主,放电类似于流注放电,射流体较长;而中心电极结构的电场集中在中心电极尖端,放电起始于电晕放电,射流体较短。同样受电场分布的影响,随着射流管内径的增大,双电极和单电极结构的射流体长度最大值先增大后逐渐趋于饱和,而中心电极结构的射流体长度最大值则略有减小。
Atmospheric pressure Ar plasma jets（APPJs） were designed to research their discharge characteristics with three kinds of different jet configurations,i.e.,double wrapped electrode,single wrapped electrode and center-electrode inside tube.The influences of flow rates,applied voltage amplitudes,and electrode configurations on the length of APPJs were studied.The results show that,as the flow rates increase,the flow status of Ar in tube has a process from the laminar state to the transition state and finally to the turbulent state.Correspondingly,the jet length first increases,then decreases,and finally reaches the maximum length when the Reynolds number is around 2000~3000.Under the same gas flow rate,the length of the single-wrapped electrode jet is slightly longer than double wrapped electrode jet while the center-electrode jet is shortest among three electrode configurations.But the discharge stability of center-electrode jet is superior to that of double-wrapped electrode jet,and the single-wrapped electrode jet is the worst.It is generally believed that the length of the jets is based on the high-energy electron in the ionization head.The electric field of double-wrapped electrode jet and single-wrapped electrode jet is mainly axial component of electric field,which leads to the discharge similar to streamer discharge and prolongs the APPJ length,while the electric field of the center-electrode jet is concentrated at the peak of the center electrode,and the discharge is originated from corona discharge with short jet length.The jet length comparison of different tube sizes shows that under our paper＇s conditions,the maximum jet length of the double-electrode jet and single-electrode jet first increases with the increment of tube sizes and finally tends to saturation,while the maximum jet length of the centre-electrode jet slightly decreases.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2011年第6期1432-1438,共7页
High Voltage Engineering
基金
全国优秀博士学位论文作者专项基金(200338)~~
