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Dynamics, OH distributions and UV emission of a gliding arc at various flow-rates investigated by optical measurements

Zhu, Jiajian LU ; Sun, Zhiwei LU ; Li, Zhongshan LU ; Ehn, Andreas LU ; Aldén, Marcus LU ; Salewski, Mirko; Leipold, Frank and Kusano, Yukihiro (2014) In Journal of Physics D: Applied Physics 47(29).
Abstract
We demonstrate a plasma discharge which is generated between two diverging electrodes and extended into a gliding arc in non-equilibrium condition by an air flow at atmospheric pressure. Effects of the air flow rates on the dynamics, ground-state OH distributions and spectral characterization of UV emission of the gliding arc were investigated by optical methods. High-speed photography was utilized to reveal flow-rate dependent dynamics such as ignitions, propagation, short-cutting events, extinctions and conversions of the discharge from glowtype to spark-type. Short-cutting events and ignitions occur more frequently at higher flow rates. The anchor points of the gliding arc are mostly steady at the top of the electrodes at lower flow... (More)
We demonstrate a plasma discharge which is generated between two diverging electrodes and extended into a gliding arc in non-equilibrium condition by an air flow at atmospheric pressure. Effects of the air flow rates on the dynamics, ground-state OH distributions and spectral characterization of UV emission of the gliding arc were investigated by optical methods. High-speed photography was utilized to reveal flow-rate dependent dynamics such as ignitions, propagation, short-cutting events, extinctions and conversions of the discharge from glowtype to spark-type. Short-cutting events and ignitions occur more frequently at higher flow rates. The anchor points of the gliding arc are mostly steady at the top of the electrodes at lower flow rates whereas at higher flow rates they glide up along the electrodes most of the time. The afterglow of fully developed gliding arcs is observed to decay over hundreds of microseconds after being electronically short-cut by a newly ignited arc. The extinction time decreases with the increase of the flow rate. The frequency of the conversion of a discharge from glow-type to spark-type increases with the flow rate. Additionally, spatial distributions of ground-state OH were investigated using planar laser-induced fluorescence. The results show that the shape, height, intensity and thickness of ground-state OH distribution vary significantly with air flow rates. Finally, UV emission of the gliding arc is measured using optical emission spectroscopy and it is found that the emission intensity of NO gamma (A-X), OH (A-X) and N-2 (C-B) increase with the flow rates showing more characteristics of spark-type arcs. The observed phenomena indicate the significance of the interaction between local turbulence and the gliding arc. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
plasma diagnostics, gliding arc, nonthermal plasma
in
Journal of Physics D: Applied Physics
volume
47
issue
29
publisher
IOP Publishing
external identifiers
  • wos:000338860300008
  • scopus:84903719678
ISSN
1361-6463
DOI
10.1088/0022-3727/47/29/295203
language
English
LU publication?
yes
id
d18bf441-6385-4c15-a253-b2f75fe01edb (old id 4598942)
date added to LUP
2014-09-05 09:13:52
date last changed
2017-10-01 04:02:09
@article{d18bf441-6385-4c15-a253-b2f75fe01edb,
  abstract     = {We demonstrate a plasma discharge which is generated between two diverging electrodes and extended into a gliding arc in non-equilibrium condition by an air flow at atmospheric pressure. Effects of the air flow rates on the dynamics, ground-state OH distributions and spectral characterization of UV emission of the gliding arc were investigated by optical methods. High-speed photography was utilized to reveal flow-rate dependent dynamics such as ignitions, propagation, short-cutting events, extinctions and conversions of the discharge from glowtype to spark-type. Short-cutting events and ignitions occur more frequently at higher flow rates. The anchor points of the gliding arc are mostly steady at the top of the electrodes at lower flow rates whereas at higher flow rates they glide up along the electrodes most of the time. The afterglow of fully developed gliding arcs is observed to decay over hundreds of microseconds after being electronically short-cut by a newly ignited arc. The extinction time decreases with the increase of the flow rate. The frequency of the conversion of a discharge from glow-type to spark-type increases with the flow rate. Additionally, spatial distributions of ground-state OH were investigated using planar laser-induced fluorescence. The results show that the shape, height, intensity and thickness of ground-state OH distribution vary significantly with air flow rates. Finally, UV emission of the gliding arc is measured using optical emission spectroscopy and it is found that the emission intensity of NO gamma (A-X), OH (A-X) and N-2 (C-B) increase with the flow rates showing more characteristics of spark-type arcs. The observed phenomena indicate the significance of the interaction between local turbulence and the gliding arc.},
  articleno    = {295203},
  author       = {Zhu, Jiajian and Sun, Zhiwei and Li, Zhongshan and Ehn, Andreas and Aldén, Marcus and Salewski, Mirko and Leipold, Frank and Kusano, Yukihiro},
  issn         = {1361-6463},
  keyword      = {plasma diagnostics,gliding arc,nonthermal plasma},
  language     = {eng},
  number       = {29},
  publisher    = {IOP Publishing},
  series       = {Journal of Physics D: Applied Physics},
  title        = {Dynamics, OH distributions and UV emission of a gliding arc at various flow-rates investigated by optical measurements},
  url          = {http://dx.doi.org/10.1088/0022-3727/47/29/295203},
  volume       = {47},
  year         = {2014},
}