Lack of universality in decaying magnetohydrodynamic turbulence

Using computations of three-dimensional magnetohydrodynamic (MHD) turbulence with a Taylor-Green flow, whose inherent time-independent symmetries are implemented numerically, and in the absence of either a forcing function or an imposed uniform magnetic field, we show that three different inertial r...

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Autor principal: Mininni, Pablo Daniel
Publicado: 2010
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v81_n1_p_Lee
http://hdl.handle.net/20.500.12110/paper_15393755_v81_n1_p_Lee
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spelling paper:paper_15393755_v81_n1_p_Lee2023-06-08T16:20:46Z Lack of universality in decaying magnetohydrodynamic turbulence Mininni, Pablo Daniel Characteristic time Computational grids Correlation time Energy spectra Forcing function Forcing terms Magnetic Prandtl numbers Magnetohydrodynamic turbulence MHD turbulence Non-linear dynamics Taylor-Green flow Taylor-Reynolds number Magnetic fields Reynolds number Spectroscopy Turbulence Magnetohydrodynamics Using computations of three-dimensional magnetohydrodynamic (MHD) turbulence with a Taylor-Green flow, whose inherent time-independent symmetries are implemented numerically, and in the absence of either a forcing function or an imposed uniform magnetic field, we show that three different inertial ranges for the energy spectrum may emerge for three different initial magnetic fields, the selecting parameter being the ratio of nonlinear eddy to Alfvén time. Equivalent computational grids range from 1283 to 20483 points with a unit magnetic Prandtl number and a Taylor Reynolds number of up to 1500 at the peak of dissipation. We also show a convergence of our results with Reynolds number. Our study is consistent with previous findings of a variety of energy spectra in MHD turbulence by studies performed in the presence of both a forcing term with a given correlation time and a strong, uniform magnetic field. However, in contrast to the previous studies, here the ratio of characteristic time scales can only be ascribed to the intrinsic nonlinear dynamics of the paradigmatic flows under study. © 2010 The American Physical Society. Fil:Mininni, P.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v81_n1_p_Lee http://hdl.handle.net/20.500.12110/paper_15393755_v81_n1_p_Lee
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Characteristic time
Computational grids
Correlation time
Energy spectra
Forcing function
Forcing terms
Magnetic Prandtl numbers
Magnetohydrodynamic turbulence
MHD turbulence
Non-linear dynamics
Taylor-Green flow
Taylor-Reynolds number
Magnetic fields
Reynolds number
Spectroscopy
Turbulence
Magnetohydrodynamics
spellingShingle Characteristic time
Computational grids
Correlation time
Energy spectra
Forcing function
Forcing terms
Magnetic Prandtl numbers
Magnetohydrodynamic turbulence
MHD turbulence
Non-linear dynamics
Taylor-Green flow
Taylor-Reynolds number
Magnetic fields
Reynolds number
Spectroscopy
Turbulence
Magnetohydrodynamics
Mininni, Pablo Daniel
Lack of universality in decaying magnetohydrodynamic turbulence
topic_facet Characteristic time
Computational grids
Correlation time
Energy spectra
Forcing function
Forcing terms
Magnetic Prandtl numbers
Magnetohydrodynamic turbulence
MHD turbulence
Non-linear dynamics
Taylor-Green flow
Taylor-Reynolds number
Magnetic fields
Reynolds number
Spectroscopy
Turbulence
Magnetohydrodynamics
description Using computations of three-dimensional magnetohydrodynamic (MHD) turbulence with a Taylor-Green flow, whose inherent time-independent symmetries are implemented numerically, and in the absence of either a forcing function or an imposed uniform magnetic field, we show that three different inertial ranges for the energy spectrum may emerge for three different initial magnetic fields, the selecting parameter being the ratio of nonlinear eddy to Alfvén time. Equivalent computational grids range from 1283 to 20483 points with a unit magnetic Prandtl number and a Taylor Reynolds number of up to 1500 at the peak of dissipation. We also show a convergence of our results with Reynolds number. Our study is consistent with previous findings of a variety of energy spectra in MHD turbulence by studies performed in the presence of both a forcing term with a given correlation time and a strong, uniform magnetic field. However, in contrast to the previous studies, here the ratio of characteristic time scales can only be ascribed to the intrinsic nonlinear dynamics of the paradigmatic flows under study. © 2010 The American Physical Society.
author Mininni, Pablo Daniel
author_facet Mininni, Pablo Daniel
author_sort Mininni, Pablo Daniel
title Lack of universality in decaying magnetohydrodynamic turbulence
title_short Lack of universality in decaying magnetohydrodynamic turbulence
title_full Lack of universality in decaying magnetohydrodynamic turbulence
title_fullStr Lack of universality in decaying magnetohydrodynamic turbulence
title_full_unstemmed Lack of universality in decaying magnetohydrodynamic turbulence
title_sort lack of universality in decaying magnetohydrodynamic turbulence
publishDate 2010
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v81_n1_p_Lee
http://hdl.handle.net/20.500.12110/paper_15393755_v81_n1_p_Lee
work_keys_str_mv AT mininnipablodaniel lackofuniversalityindecayingmagnetohydrodynamicturbulence
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