Conserving Local Magnetic Helicity in Numerical Simulations
Magnetic helicity is robustly conserved in systems with very large magnetic Reynolds numbers, including most systems of astrophysical interest, and unlike kinetic and magnetic energy, it is not dissipated at small scales. This plays a major role in suppressing the kinematic large-scale dynamo and ma...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acca1e |
| _version_ | 1797696146636800000 |
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| author | Yossef Zenati Ethan T. Vishniac |
| author_facet | Yossef Zenati Ethan T. Vishniac |
| author_sort | Yossef Zenati |
| collection | DOAJ |
| description | Magnetic helicity is robustly conserved in systems with very large magnetic Reynolds numbers, including most systems of astrophysical interest, and unlike kinetic and magnetic energy, it is not dissipated at small scales. This plays a major role in suppressing the kinematic large-scale dynamo and may also be responsible for driving the large-scale dynamo through the magnetic helicity flux. Numerical simulations of astrophysical systems typically lack sufficient resolution to enforce global magnetic helicity over several dynamical times. In these simulations, magnetic helicity is lost either through numerical errors or through the action of an unrealistically large resistivity. Errors in the internal distribution of magnetic helicity are equally important and typically larger. Here, we propose an algorithm for enforcing strict local conservation of magnetic helicity in the Coulomb gauge in numerical simulations, so that their evolution more closely approximates that of real systems. |
| first_indexed | 2024-03-12T03:22:29Z |
| format | Article |
| id | doaj.art-ac3c57594ab24fddb00b5b5d68dbab5a |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:22:29Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-ac3c57594ab24fddb00b5b5d68dbab5a2023-09-03T13:50:57ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194811110.3847/1538-4357/acca1eConserving Local Magnetic Helicity in Numerical SimulationsYossef Zenati0https://orcid.org/0000-0002-0632-8897Ethan T. Vishniac1https://orcid.org/0000-0002-2307-3857Physics and Astronomy Department, Johns Hopkins University , Baltimore, MD 21218, USA ; yzenati1@jhu.eduPhysics and Astronomy Department, Johns Hopkins University , Baltimore, MD 21218, USA ; yzenati1@jhu.eduMagnetic helicity is robustly conserved in systems with very large magnetic Reynolds numbers, including most systems of astrophysical interest, and unlike kinetic and magnetic energy, it is not dissipated at small scales. This plays a major role in suppressing the kinematic large-scale dynamo and may also be responsible for driving the large-scale dynamo through the magnetic helicity flux. Numerical simulations of astrophysical systems typically lack sufficient resolution to enforce global magnetic helicity over several dynamical times. In these simulations, magnetic helicity is lost either through numerical errors or through the action of an unrealistically large resistivity. Errors in the internal distribution of magnetic helicity are equally important and typically larger. Here, we propose an algorithm for enforcing strict local conservation of magnetic helicity in the Coulomb gauge in numerical simulations, so that their evolution more closely approximates that of real systems.https://doi.org/10.3847/1538-4357/acca1eAstrophysical fluid dynamicsMagnetic fieldsMagnetohydrodynamics |
| spellingShingle | Yossef Zenati Ethan T. Vishniac Conserving Local Magnetic Helicity in Numerical Simulations The Astrophysical Journal Astrophysical fluid dynamics Magnetic fields Magnetohydrodynamics |
| title | Conserving Local Magnetic Helicity in Numerical Simulations |
| title_full | Conserving Local Magnetic Helicity in Numerical Simulations |
| title_fullStr | Conserving Local Magnetic Helicity in Numerical Simulations |
| title_full_unstemmed | Conserving Local Magnetic Helicity in Numerical Simulations |
| title_short | Conserving Local Magnetic Helicity in Numerical Simulations |
| title_sort | conserving local magnetic helicity in numerical simulations |
| topic | Astrophysical fluid dynamics Magnetic fields Magnetohydrodynamics |
| url | https://doi.org/10.3847/1538-4357/acca1e |
| work_keys_str_mv | AT yossefzenati conservinglocalmagnetichelicityinnumericalsimulations AT ethantvishniac conservinglocalmagnetichelicityinnumericalsimulations |