Development of Strongly Dissipative Mhd Structures
A plasma flow near a stagnation point, which may be produced by a local squeezing in one direction with outflow on both sides of a central channel, convects a magnetic field towards the inner layer, while enhancement of the initial magnetic energy and formation of a current sheet with intense Joule...
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1992
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00933813_v20_n6_p882_Gratton http://hdl.handle.net/20.500.12110/paper_00933813_v20_n6_p882_Gratton |
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paper:paper_00933813_v20_n6_p882_Gratton2023-06-08T15:08:33Z Development of Strongly Dissipative Mhd Structures Gratton, Fausto Tulio Livio Gnavi, Graciela Delia Bender, Laurence E. Magnetic fields Magnetohydrodynamics Numerical analysis Current sheets Joule dissipation Magnetic energy Plasma stability A plasma flow near a stagnation point, which may be produced by a local squeezing in one direction with outflow on both sides of a central channel, convects a magnetic field towards the inner layer, while enhancement of the initial magnetic energy and formation of a current sheet with intense Joule dissipation rates take place when the magnetic Reynolds number is large. In systems with no magnetic flux injection, starting from a generic initial magnetic field and after a transient in which amplification followed by annihilation of the odd component occurs, a large even magnetic remnant concentrated in a thin slab is formed in a few hydrodynamic times. If the pressure gradient that drives the motion is switched off, the magnetic field extinguishes at a much slower pace than the corresponding buildup process. When there is continuous magnetic flux injection, the even component of the magnetic field, in general, becomes dominant over the odd part after some number of hydrodynamic times. For astrophysical plasmas the significance of the mechanism considered here is that i) fast dissipation of magnetic energy does not invoke anomalous resistivity, and ii) neutral sublayers where change of sign of magnetic field occurs may vanish during the current sheet evolution, so that steady-state configurations prone to processes of reconnection or tearing instabilities do not develop. © 1992 IEEE Fil:Gratton, F.T. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Gnavi, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Bender, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1992 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00933813_v20_n6_p882_Gratton http://hdl.handle.net/20.500.12110/paper_00933813_v20_n6_p882_Gratton |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Magnetic fields Magnetohydrodynamics Numerical analysis Current sheets Joule dissipation Magnetic energy Plasma stability |
spellingShingle |
Magnetic fields Magnetohydrodynamics Numerical analysis Current sheets Joule dissipation Magnetic energy Plasma stability Gratton, Fausto Tulio Livio Gnavi, Graciela Delia Bender, Laurence E. Development of Strongly Dissipative Mhd Structures |
topic_facet |
Magnetic fields Magnetohydrodynamics Numerical analysis Current sheets Joule dissipation Magnetic energy Plasma stability |
description |
A plasma flow near a stagnation point, which may be produced by a local squeezing in one direction with outflow on both sides of a central channel, convects a magnetic field towards the inner layer, while enhancement of the initial magnetic energy and formation of a current sheet with intense Joule dissipation rates take place when the magnetic Reynolds number is large. In systems with no magnetic flux injection, starting from a generic initial magnetic field and after a transient in which amplification followed by annihilation of the odd component occurs, a large even magnetic remnant concentrated in a thin slab is formed in a few hydrodynamic times. If the pressure gradient that drives the motion is switched off, the magnetic field extinguishes at a much slower pace than the corresponding buildup process. When there is continuous magnetic flux injection, the even component of the magnetic field, in general, becomes dominant over the odd part after some number of hydrodynamic times. For astrophysical plasmas the significance of the mechanism considered here is that i) fast dissipation of magnetic energy does not invoke anomalous resistivity, and ii) neutral sublayers where change of sign of magnetic field occurs may vanish during the current sheet evolution, so that steady-state configurations prone to processes of reconnection or tearing instabilities do not develop. © 1992 IEEE |
author |
Gratton, Fausto Tulio Livio Gnavi, Graciela Delia Bender, Laurence E. |
author_facet |
Gratton, Fausto Tulio Livio Gnavi, Graciela Delia Bender, Laurence E. |
author_sort |
Gratton, Fausto Tulio Livio |
title |
Development of Strongly Dissipative Mhd Structures |
title_short |
Development of Strongly Dissipative Mhd Structures |
title_full |
Development of Strongly Dissipative Mhd Structures |
title_fullStr |
Development of Strongly Dissipative Mhd Structures |
title_full_unstemmed |
Development of Strongly Dissipative Mhd Structures |
title_sort |
development of strongly dissipative mhd structures |
publishDate |
1992 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00933813_v20_n6_p882_Gratton http://hdl.handle.net/20.500.12110/paper_00933813_v20_n6_p882_Gratton |
work_keys_str_mv |
AT grattonfaustotuliolivio developmentofstronglydissipativemhdstructures AT gnavigracieladelia developmentofstronglydissipativemhdstructures AT benderlaurencee developmentofstronglydissipativemhdstructures |
_version_ |
1768541979937865728 |