Direct numerical simulations of helical dynamo action: MHD and beyond
Magnetohydrodynamic dynamo action is often invoked to explain the existence of magnetic fields in several astronomical objects. In this work, we present direct numerical simulations of MHD helical dynamos, to study the exponential growth and saturation of magnetic fields. Simulations are made within...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_10235809_v11_n5-6_p619_Gomez |
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todo:paper_10235809_v11_n5-6_p619_Gomez2023-10-03T15:56:48Z Direct numerical simulations of helical dynamo action: MHD and beyond Gómez, D.O. Mininni, P.D. magnetohydrodynamics numerical model Magnetohydrodynamic dynamo action is often invoked to explain the existence of magnetic fields in several astronomical objects. In this work, we present direct numerical simulations of MHD helical dynamos, to study the exponential growth and saturation of magnetic fields. Simulations are made within the framework of incompressible flows and using periodic boundary conditions. The statistical properties of the flow are studied, and it is found that its helicity displays strong spatial fluctuations. Regions with large kinetic helicity are also strongly concentrated in space, forming elongated structures. In dynamo simulations using these flows, we found that the growth rate and the saturation level of magnetic energy and magnetic helicity reach an asymptotic value as the Reynolds number is increased. Finally, extensions of the MHD theory to include kinetic effects relevant in astrophysical environments are discussed. © European Geosciences Union 2004. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_10235809_v11_n5-6_p619_Gomez |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
magnetohydrodynamics numerical model |
| spellingShingle |
magnetohydrodynamics numerical model Gómez, D.O. Mininni, P.D. Direct numerical simulations of helical dynamo action: MHD and beyond |
| topic_facet |
magnetohydrodynamics numerical model |
| description |
Magnetohydrodynamic dynamo action is often invoked to explain the existence of magnetic fields in several astronomical objects. In this work, we present direct numerical simulations of MHD helical dynamos, to study the exponential growth and saturation of magnetic fields. Simulations are made within the framework of incompressible flows and using periodic boundary conditions. The statistical properties of the flow are studied, and it is found that its helicity displays strong spatial fluctuations. Regions with large kinetic helicity are also strongly concentrated in space, forming elongated structures. In dynamo simulations using these flows, we found that the growth rate and the saturation level of magnetic energy and magnetic helicity reach an asymptotic value as the Reynolds number is increased. Finally, extensions of the MHD theory to include kinetic effects relevant in astrophysical environments are discussed. © European Geosciences Union 2004. |
| format |
JOUR |
| author |
Gómez, D.O. Mininni, P.D. |
| author_facet |
Gómez, D.O. Mininni, P.D. |
| author_sort |
Gómez, D.O. |
| title |
Direct numerical simulations of helical dynamo action: MHD and beyond |
| title_short |
Direct numerical simulations of helical dynamo action: MHD and beyond |
| title_full |
Direct numerical simulations of helical dynamo action: MHD and beyond |
| title_fullStr |
Direct numerical simulations of helical dynamo action: MHD and beyond |
| title_full_unstemmed |
Direct numerical simulations of helical dynamo action: MHD and beyond |
| title_sort |
direct numerical simulations of helical dynamo action: mhd and beyond |
| url |
http://hdl.handle.net/20.500.12110/paper_10235809_v11_n5-6_p619_Gomez |
| work_keys_str_mv |
AT gomezdo directnumericalsimulationsofhelicaldynamoactionmhdandbeyond AT mininnipd directnumericalsimulationsofhelicaldynamoactionmhdandbeyond |
| _version_ |
1807318547714539520 |