Numerical investigation of the double-arcing phenomenon in a cutting arc torch

A numerical investigation of the double-arcing phenomenon in a cutting arc torch is reported. The dynamics of the double-arcing were simulated by using a two-dimensional model of the gas breakdown development in the space-charge layer contiguous to the nozzle of a cutting arc torch operated with oxy...

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Autores principales: Minotti, Fernando Oscar, Kelly, Héctor Juan
Publicado: 2014
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218979_v116_n2_p_Mancinelli
http://hdl.handle.net/20.500.12110/paper_00218979_v116_n2_p_Mancinelli
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spelling paper:paper_00218979_v116_n2_p_Mancinelli2023-06-08T14:42:52Z Numerical investigation of the double-arcing phenomenon in a cutting arc torch Minotti, Fernando Oscar Kelly, Héctor Juan Computer simulation Electron emission Electrons Impact ionization Ions Oxygen cutting Displacement currents Electron attachment Electron detachments Electron-ion recombinations Ion-ion recombinations Numerical investigations Space-charge layers Two dimensional model Nozzles A numerical investigation of the double-arcing phenomenon in a cutting arc torch is reported. The dynamics of the double-arcing were simulated by using a two-dimensional model of the gas breakdown development in the space-charge layer contiguous to the nozzle of a cutting arc torch operated with oxygen. The kinetic scheme includes ionization of heavy particles by electron impact, electron attachment, electron detachment, electron-ion recombination, and ion-ion recombination. Complementary measurements during double-arcing phenomena were also conducted. A marked rise of the nozzle voltage was found. The numerical results showed that the dynamics of a cathode spot at the exit of the nozzle inner surface play a key role in the raising of the nozzle voltage, which in turn allows more electrons to return to the wall at the nozzle inlet. The return flow of electrons thus closes the current loop of the double-arcing. The increase in the (floating) nozzle voltage is due to the fact that the increased electron emission at the spot is mainly compensated by the displacement current (the ions do not play a relevant role due to its low-mobility) until that the stationary state is achieved and the electron return flow fully-compensates the electron emission at the spot. A fairly good agreement was found between the model and the experiment for a spot emission current growth rate of the order of 7×104A/s. © 2014 AIP Publishing LLC. Fil:Minotti, F.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Kelly, H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218979_v116_n2_p_Mancinelli http://hdl.handle.net/20.500.12110/paper_00218979_v116_n2_p_Mancinelli
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Computer simulation
Electron emission
Electrons
Impact ionization
Ions
Oxygen cutting
Displacement currents
Electron attachment
Electron detachments
Electron-ion recombinations
Ion-ion recombinations
Numerical investigations
Space-charge layers
Two dimensional model
Nozzles
spellingShingle Computer simulation
Electron emission
Electrons
Impact ionization
Ions
Oxygen cutting
Displacement currents
Electron attachment
Electron detachments
Electron-ion recombinations
Ion-ion recombinations
Numerical investigations
Space-charge layers
Two dimensional model
Nozzles
Minotti, Fernando Oscar
Kelly, Héctor Juan
Numerical investigation of the double-arcing phenomenon in a cutting arc torch
topic_facet Computer simulation
Electron emission
Electrons
Impact ionization
Ions
Oxygen cutting
Displacement currents
Electron attachment
Electron detachments
Electron-ion recombinations
Ion-ion recombinations
Numerical investigations
Space-charge layers
Two dimensional model
Nozzles
description A numerical investigation of the double-arcing phenomenon in a cutting arc torch is reported. The dynamics of the double-arcing were simulated by using a two-dimensional model of the gas breakdown development in the space-charge layer contiguous to the nozzle of a cutting arc torch operated with oxygen. The kinetic scheme includes ionization of heavy particles by electron impact, electron attachment, electron detachment, electron-ion recombination, and ion-ion recombination. Complementary measurements during double-arcing phenomena were also conducted. A marked rise of the nozzle voltage was found. The numerical results showed that the dynamics of a cathode spot at the exit of the nozzle inner surface play a key role in the raising of the nozzle voltage, which in turn allows more electrons to return to the wall at the nozzle inlet. The return flow of electrons thus closes the current loop of the double-arcing. The increase in the (floating) nozzle voltage is due to the fact that the increased electron emission at the spot is mainly compensated by the displacement current (the ions do not play a relevant role due to its low-mobility) until that the stationary state is achieved and the electron return flow fully-compensates the electron emission at the spot. A fairly good agreement was found between the model and the experiment for a spot emission current growth rate of the order of 7×104A/s. © 2014 AIP Publishing LLC.
author Minotti, Fernando Oscar
Kelly, Héctor Juan
author_facet Minotti, Fernando Oscar
Kelly, Héctor Juan
author_sort Minotti, Fernando Oscar
title Numerical investigation of the double-arcing phenomenon in a cutting arc torch
title_short Numerical investigation of the double-arcing phenomenon in a cutting arc torch
title_full Numerical investigation of the double-arcing phenomenon in a cutting arc torch
title_fullStr Numerical investigation of the double-arcing phenomenon in a cutting arc torch
title_full_unstemmed Numerical investigation of the double-arcing phenomenon in a cutting arc torch
title_sort numerical investigation of the double-arcing phenomenon in a cutting arc torch
publishDate 2014
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00218979_v116_n2_p_Mancinelli
http://hdl.handle.net/20.500.12110/paper_00218979_v116_n2_p_Mancinelli
work_keys_str_mv AT minottifernandooscar numericalinvestigationofthedoublearcingphenomenoninacuttingarctorch
AT kellyhectorjuan numericalinvestigationofthedoublearcingphenomenoninacuttingarctorch
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