The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel

The low-mode model αΩ-dynamo is used in this paper to simulate the modes of magnetic field generation with insignificant changes in the velocity field of a viscous fluid. In the framework of those model the α-effect intensity is regulated by the process that is included in the magnetohydrodynamic sy...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Sheremetyeva Olga V., Godomskaya Anna N.
Formato:	article
Lenguaje:	EN
Publicado:	EDP Sciences 2021
Materias:	αω-dynamo magnetohydrodynamic system α-effect additive correction α-effect intensity variation modes of magnetic field generation reversal Physics QC1-999
Acceso en línea:	https://doaj.org/article/5e34de797b09494e9aa9a37668257d42
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:5e34de797b09494e9aa9a37668257d42
record_format	dspace
spelling	oai:doaj.org-article:5e34de797b09494e9aa9a37668257d422021-11-12T11:44:52ZThe modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel2100-014X10.1051/epjconf/202125402015https://doaj.org/article/5e34de797b09494e9aa9a37668257d422021-01-01T00:00:00Zhttps://www.epj-conferences.org/articles/epjconf/pdf/2021/08/epjconf_strpep2021_02015.pdfhttps://doaj.org/toc/2100-014XThe low-mode model αΩ-dynamo is used in this paper to simulate the modes of magnetic field generation with insignificant changes in the velocity field of a viscous fluid. In the framework of those model the α-effect intensity is regulated by the process that is included in the magnetohydrodynamic system (MHD-system) as an additive correction as a functional Z(t) depended on the magnetic field energy. Function that determines damped oscillations with variable damping frequency and constant damping coefficient, taken equal to one, is selected as kernel J(t) of functional Z(t). The research of the behavior of the magnetic field is carried out on large time scales, therefore, a rescaled and dimensionless MHD-system with the unit of time iquel the time of the magnetic field dissipation (104 years) for numerical calculations is used. The control parameters of the system are the Reynolds number and the amplitude of the α-effect, that include information about the large-scale and turbulent generators, respectively. Numerical simulation of the magnetic field generation modes was carried out for the values of the damping coefficient b = 1 and frequency a = 0.1, 0.5, 1, 5, 10. According to the results of numerical simulation, an increase in the values of the damping frequency, when the damping coefficient is equal to one, is characterized by a decrease in the inhibitory effect of the process Z(t) on the α-effect and an increase in the region of divergence of the magnetic field on the phase plane of the control parameters. In a comparative analysis with the results of the authors’ work, where the change of the α-effect intensity was determined by the function Z(t) with an exponential kernel and the same value of the damping coefficient, the following differences were noted: an increase in oscillations in both a magnetic and a velocity fields, the appearance of a chaotic regime of magnetic field generation at the value of the damping frequency equal to one, and also insignificant narrowing of the region of α-effect suppression at values of the damping frequency increasing to one.Sheremetyeva Olga V.Godomskaya Anna N.EDP Sciencesarticleαω-dynamomagnetohydrodynamic systemα-effect additive correctionα-effect intensity variationmodes of magnetic field generationreversalPhysicsQC1-999ENEPJ Web of Conferences, Vol 254, p 02015 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	αω-dynamo magnetohydrodynamic system α-effect additive correction α-effect intensity variation modes of magnetic field generation reversal Physics QC1-999
spellingShingle	αω-dynamo magnetohydrodynamic system α-effect additive correction α-effect intensity variation modes of magnetic field generation reversal Physics QC1-999 Sheremetyeva Olga V. Godomskaya Anna N. The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
description	The low-mode model αΩ-dynamo is used in this paper to simulate the modes of magnetic field generation with insignificant changes in the velocity field of a viscous fluid. In the framework of those model the α-effect intensity is regulated by the process that is included in the magnetohydrodynamic system (MHD-system) as an additive correction as a functional Z(t) depended on the magnetic field energy. Function that determines damped oscillations with variable damping frequency and constant damping coefficient, taken equal to one, is selected as kernel J(t) of functional Z(t). The research of the behavior of the magnetic field is carried out on large time scales, therefore, a rescaled and dimensionless MHD-system with the unit of time iquel the time of the magnetic field dissipation (104 years) for numerical calculations is used. The control parameters of the system are the Reynolds number and the amplitude of the α-effect, that include information about the large-scale and turbulent generators, respectively. Numerical simulation of the magnetic field generation modes was carried out for the values of the damping coefficient b = 1 and frequency a = 0.1, 0.5, 1, 5, 10. According to the results of numerical simulation, an increase in the values of the damping frequency, when the damping coefficient is equal to one, is characterized by a decrease in the inhibitory effect of the process Z(t) on the α-effect and an increase in the region of divergence of the magnetic field on the phase plane of the control parameters. In a comparative analysis with the results of the authors’ work, where the change of the α-effect intensity was determined by the function Z(t) with an exponential kernel and the same value of the damping coefficient, the following differences were noted: an increase in oscillations in both a magnetic and a velocity fields, the appearance of a chaotic regime of magnetic field generation at the value of the damping frequency equal to one, and also insignificant narrowing of the region of α-effect suppression at values of the damping frequency increasing to one.
format	article
author	Sheremetyeva Olga V. Godomskaya Anna N.
author_facet	Sheremetyeva Olga V. Godomskaya Anna N.
author_sort	Sheremetyeva Olga V.
title	The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
title_short	The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
title_full	The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
title_fullStr	The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
title_full_unstemmed	The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
title_sort	modes of magnetic field generation in a low-mode model of αω-dynamo with α-generator varying intensity regulated by a function with an alternating kernel
publisher	EDP Sciences
publishDate	2021
url	https://doaj.org/article/5e34de797b09494e9aa9a37668257d42
work_keys_str_mv	AT sheremetyevaolgav themodesofmagneticfieldgenerationinalowmodemodelofaōdynamowithageneratorvaryingintensityregulatedbyafunctionwithanalternatingkernel AT godomskayaannan themodesofmagneticfieldgenerationinalowmodemodelofaōdynamowithageneratorvaryingintensityregulatedbyafunctionwithanalternatingkernel AT sheremetyevaolgav modesofmagneticfieldgenerationinalowmodemodelofaōdynamowithageneratorvaryingintensityregulatedbyafunctionwithanalternatingkernel AT godomskayaannan modesofmagneticfieldgenerationinalowmodemodelofaōdynamowithageneratorvaryingintensityregulatedbyafunctionwithanalternatingkernel
_version_	1718430554986119168

The modes of magnetic field generation in a low-mode model of αΩ-dynamo with α-generator varying intensity regulated by a function with an alternating kernel

Ejemplares similares