On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode
The present work provides a detailed kinetic analysis of the time-resolved dynamics of the gas heating during the arc reattachment in nitrogen gas in order to understand the main processes leading to such a fast reattachment. The model includes gas heating due to the relaxation of the energy stored...
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2015
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724324_v35_n6_p1057_Prevosto http://hdl.handle.net/20.500.12110/paper_02724324_v35_n6_p1057_Prevosto |
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paper:paper_02724324_v35_n6_p1057_Prevosto2023-06-08T15:25:01Z On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode Anode arc reattachment Fast gas heating Plasma torches Vibrational instability Electric discharges Electric fields Electrodes Electron energy levels Gas heating Gases Heating Ionization of gases Nitrogen Nitrogen plasma Plasma diagnostics Plasma stability Plasma torches Arc reattachment Detailed kinetics Electron energies Heating mechanisms High current densities Time-resolved dynamics Translational energy Vibrational instabilities Hard facing The present work provides a detailed kinetic analysis of the time-resolved dynamics of the gas heating during the arc reattachment in nitrogen gas in order to understand the main processes leading to such a fast reattachment. The model includes gas heating due to the relaxation of the energy stored in the vibrational as well as the electronic modes of the molecules. The results show that the anode arc reattachment is essentiality a threshold process, corresponding to a reduced electric field value of E/N ~ 40 Td for the plasma discharge conditions considered in this work. The arc reattachment is triggered by a vibrational instability whose development requires a time of the order of 100 µs. For E/N < 80–100 Td, most of the electron energy is transferred to gas heating through the mechanism of vibrational–translational relaxation. For larger values of E/N the electronic–translational energy relaxation mechanism produces a further intensification of the gas heating. The sharp increase of the gas heating rate during the last few µs of the vibrational instability give rises to a sudden transition from a diffuse (glow-like) discharge to a constricted arc with a high current density (~107 A/m2). This sudden increase in the current density gives rise to a new anode attachment closer to the cathode (where the voltage drop between the original arc and the anode is the largest) thus causing the decay of the old arc spot. © 2015, Springer Science+Business Media New York. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724324_v35_n6_p1057_Prevosto http://hdl.handle.net/20.500.12110/paper_02724324_v35_n6_p1057_Prevosto |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Anode arc reattachment Fast gas heating Plasma torches Vibrational instability Electric discharges Electric fields Electrodes Electron energy levels Gas heating Gases Heating Ionization of gases Nitrogen Nitrogen plasma Plasma diagnostics Plasma stability Plasma torches Arc reattachment Detailed kinetics Electron energies Heating mechanisms High current densities Time-resolved dynamics Translational energy Vibrational instabilities Hard facing |
| spellingShingle |
Anode arc reattachment Fast gas heating Plasma torches Vibrational instability Electric discharges Electric fields Electrodes Electron energy levels Gas heating Gases Heating Ionization of gases Nitrogen Nitrogen plasma Plasma diagnostics Plasma stability Plasma torches Arc reattachment Detailed kinetics Electron energies Heating mechanisms High current densities Time-resolved dynamics Translational energy Vibrational instabilities Hard facing On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| topic_facet |
Anode arc reattachment Fast gas heating Plasma torches Vibrational instability Electric discharges Electric fields Electrodes Electron energy levels Gas heating Gases Heating Ionization of gases Nitrogen Nitrogen plasma Plasma diagnostics Plasma stability Plasma torches Arc reattachment Detailed kinetics Electron energies Heating mechanisms High current densities Time-resolved dynamics Translational energy Vibrational instabilities Hard facing |
| description |
The present work provides a detailed kinetic analysis of the time-resolved dynamics of the gas heating during the arc reattachment in nitrogen gas in order to understand the main processes leading to such a fast reattachment. The model includes gas heating due to the relaxation of the energy stored in the vibrational as well as the electronic modes of the molecules. The results show that the anode arc reattachment is essentiality a threshold process, corresponding to a reduced electric field value of E/N ~ 40 Td for the plasma discharge conditions considered in this work. The arc reattachment is triggered by a vibrational instability whose development requires a time of the order of 100 µs. For E/N < 80–100 Td, most of the electron energy is transferred to gas heating through the mechanism of vibrational–translational relaxation. For larger values of E/N the electronic–translational energy relaxation mechanism produces a further intensification of the gas heating. The sharp increase of the gas heating rate during the last few µs of the vibrational instability give rises to a sudden transition from a diffuse (glow-like) discharge to a constricted arc with a high current density (~107 A/m2). This sudden increase in the current density gives rise to a new anode attachment closer to the cathode (where the voltage drop between the original arc and the anode is the largest) thus causing the decay of the old arc spot. © 2015, Springer Science+Business Media New York. |
| title |
On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| title_short |
On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| title_full |
On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| title_fullStr |
On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| title_full_unstemmed |
On the Gas Heating Mechanism for the Fast Anode Arc Reattachment in a Non-transferred Arc Plasma Torch Operating with Nitrogen Gas in the Restrike Mode |
| title_sort |
on the gas heating mechanism for the fast anode arc reattachment in a non-transferred arc plasma torch operating with nitrogen gas in the restrike mode |
| publishDate |
2015 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02724324_v35_n6_p1057_Prevosto http://hdl.handle.net/20.500.12110/paper_02724324_v35_n6_p1057_Prevosto |
| _version_ |
1768544316925411328 |