Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals
Planets and stars are often capable of generating their own magnetic fields. This occurs through dynamo processes occurring via turbulent convective stirring of their respective molten metal-rich cores and plasma-based convection zones. Present-day numerical models of planetary and stellar dynamo ac...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2015-03-01
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| Series: | Metals |
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| Online Access: | http://www.mdpi.com/2075-4701/5/1/289 |
| _version_ | 1819264941343899648 |
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| author | Adolfo Ribeiro Guillaume Fabre Jean-Luc Guermond Jonathan M. Aurnou |
| author_facet | Adolfo Ribeiro Guillaume Fabre Jean-Luc Guermond Jonathan M. Aurnou |
| author_sort | Adolfo Ribeiro |
| collection | DOAJ |
| description | Planets and stars are often capable of generating their own magnetic fields. This occurs through dynamo processes occurring via turbulent convective stirring of their respective molten metal-rich cores and plasma-based convection zones. Present-day numerical models of planetary and stellar dynamo action are not carried out using fluids properties that mimic the essential properties of liquid metals and plasmas (e.g., using fluids with thermal Prandtl numbers Pr < 1 and magnetic Prandtl numbers Pm ≪ 1). Metal dynamo simulations should become possible, though, within the next decade. In order then to understand the turbulent convection phenomena occurring in geophysical or astrophysical fluids and next-generation numerical models thereof, we present here canonical, end-member examples of thermally-driven convection in liquid gallium, first with no magnetic field or rotation present, then with the inclusion of a background magnetic field and then in a rotating system (without an imposed magnetic field). In doing so, we demonstrate the essential behaviors of convecting liquid metals that are necessary for building, as well as benchmarking, accurate, robust models of magnetohydrodynamic processes in Pm ≪ Pr < 1 geophysical and astrophysical systems. Our study results also show strong agreement between laboratory and numerical experiments, demonstrating that high resolution numerical simulations can be made capable of modeling the liquid metal convective turbulence needed in accurate next-generation dynamo models. |
| first_indexed | 2024-12-23T20:37:29Z |
| format | Article |
| id | doaj.art-b4707d40a1be4a8f8fe5d373edb3644c |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-23T20:37:29Z |
| publishDate | 2015-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-b4707d40a1be4a8f8fe5d373edb3644c2022-12-21T17:32:03ZengMDPI AGMetals2075-47012015-03-015128933510.3390/met5010289met5010289Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid MetalsAdolfo Ribeiro0Guillaume Fabre1Jean-Luc Guermond2Jonathan M. Aurnou3Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA 90095, USADepartment of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA 90095, USADepartment of Mathematics, Texas A & M University, College Station, TX 77843, USADepartment of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA 90095, USAPlanets and stars are often capable of generating their own magnetic fields. This occurs through dynamo processes occurring via turbulent convective stirring of their respective molten metal-rich cores and plasma-based convection zones. Present-day numerical models of planetary and stellar dynamo action are not carried out using fluids properties that mimic the essential properties of liquid metals and plasmas (e.g., using fluids with thermal Prandtl numbers Pr < 1 and magnetic Prandtl numbers Pm ≪ 1). Metal dynamo simulations should become possible, though, within the next decade. In order then to understand the turbulent convection phenomena occurring in geophysical or astrophysical fluids and next-generation numerical models thereof, we present here canonical, end-member examples of thermally-driven convection in liquid gallium, first with no magnetic field or rotation present, then with the inclusion of a background magnetic field and then in a rotating system (without an imposed magnetic field). In doing so, we demonstrate the essential behaviors of convecting liquid metals that are necessary for building, as well as benchmarking, accurate, robust models of magnetohydrodynamic processes in Pm ≪ Pr < 1 geophysical and astrophysical systems. Our study results also show strong agreement between laboratory and numerical experiments, demonstrating that high resolution numerical simulations can be made capable of modeling the liquid metal convective turbulence needed in accurate next-generation dynamo models.http://www.mdpi.com/2075-4701/5/1/289convectionturbulencemagnetohydrodynamicsgeophysicsastrophysicsliquid metalsgallium |
| spellingShingle | Adolfo Ribeiro Guillaume Fabre Jean-Luc Guermond Jonathan M. Aurnou Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals Metals convection turbulence magnetohydrodynamics geophysics astrophysics liquid metals gallium |
| title | Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals |
| title_full | Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals |
| title_fullStr | Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals |
| title_full_unstemmed | Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals |
| title_short | Canonical Models of Geophysical and Astrophysical Flows: Turbulent Convection Experiments in Liquid Metals |
| title_sort | canonical models of geophysical and astrophysical flows turbulent convection experiments in liquid metals |
| topic | convection turbulence magnetohydrodynamics geophysics astrophysics liquid metals gallium |
| url | http://www.mdpi.com/2075-4701/5/1/289 |
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