中国物理B ›› 2015, Vol. 24 ›› Issue (12): 125203-125203.doi: 10.1088/1674-1056/24/12/125203

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

A two-dimensional model of He/O2 atmospheric pressure plasma needle discharge

钱沐杨a, 杨从影a, 陈小昌a, 刘三秋a, 晏雯b, 刘富成c, 王德真b   

  1. a Department of Physics, Nanchang University, Nanchang 330031, China;
    b School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023, China;
    c College of Physics Science and Technology, Hebei University, Baoding 071002, China
  • 收稿日期:2015-05-27 修回日期:2015-08-26 出版日期:2015-12-05 发布日期:2015-12-05
  • 通讯作者: Qian Mu-Yang E-mail:qianmuyang@ncu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11465013), the International Science and Technology Cooperation Program of China (Grant No. 2015DFA61800), and the Natural Science Foundation of Jiangxi Province, China (Grant No. 20151BAB212012).

A two-dimensional model of He/O2 atmospheric pressure plasma needle discharge

Qian Mu-Yang (钱沐杨)a, Yang Cong-Ying (杨从影)a, Chen Xiao-Chang (陈小昌)a, Liu San-Qiu (刘三秋)a, Yan Wen (晏雯)b, Liu Fu-Cheng (刘富成)c, Wang De-Zhen (王德真)b   

  1. a Department of Physics, Nanchang University, Nanchang 330031, China;
    b School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023, China;
    c College of Physics Science and Technology, Hebei University, Baoding 071002, China
  • Received:2015-05-27 Revised:2015-08-26 Online:2015-12-05 Published:2015-12-05
  • Contact: Qian Mu-Yang E-mail:qianmuyang@ncu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11465013), the International Science and Technology Cooperation Program of China (Grant No. 2015DFA61800), and the Natural Science Foundation of Jiangxi Province, China (Grant No. 20151BAB212012).

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摘要： In this paper, a computational modeling study of stream propagation in the atmospheric-pressure helium plasma in ambient atmosphere (oxygen) is presented. A coupled fluid model between time-dependent plasma dynamics and steady state neutral gas flow is employed to provide a fundamental insight into the evolution of the streamers. The obtained simulation results showing that the sheath forms near the dielectric surface and shields the axial stream propagation. The stream front propagates with axial velocity in a range of 104 m/s-105 m/s. And, the increasing accumulated surface charge should be responsible for reducing the propagation velocity of the streamer front in the axial direction. Besides, when the gas flow rate is 1.1 standard liter per minute (SLM), we find that the concentration of oxygen drastically increases at a larger radial position near a treated surface. Therefore, Penning ionization by helium metastables and oxygen peaks at an off-axis position, corresponding to the ring-shaped emission profile in cylindrical coordinates. In this case, the simulated results show the ring-shaped ground atomic oxygen density profile near the treated surface (z=0.5 mm) at a large gas flow rate of 1.1 SLM, which is consistent with the observation in a similar experiment.

关键词: atmospheric pressure plasma needle discharge, streamer dynamics, cathode sheath

Abstract: In this paper, a computational modeling study of stream propagation in the atmospheric-pressure helium plasma in ambient atmosphere (oxygen) is presented. A coupled fluid model between time-dependent plasma dynamics and steady state neutral gas flow is employed to provide a fundamental insight into the evolution of the streamers. The obtained simulation results showing that the sheath forms near the dielectric surface and shields the axial stream propagation. The stream front propagates with axial velocity in a range of 104 m/s-105 m/s. And, the increasing accumulated surface charge should be responsible for reducing the propagation velocity of the streamer front in the axial direction. Besides, when the gas flow rate is 1.1 standard liter per minute (SLM), we find that the concentration of oxygen drastically increases at a larger radial position near a treated surface. Therefore, Penning ionization by helium metastables and oxygen peaks at an off-axis position, corresponding to the ring-shaped emission profile in cylindrical coordinates. In this case, the simulated results show the ring-shaped ground atomic oxygen density profile near the treated surface (z=0.5 mm) at a large gas flow rate of 1.1 SLM, which is consistent with the observation in a similar experiment.

Key words: atmospheric pressure plasma needle discharge, streamer dynamics, cathode sheath

中图分类号:  (Magnetohydrodynamic and fluid equation)

  • 52.65.Kj
52.40.Kh (Plasma sheaths) 52.25.Fi (Transport properties)