Analytic characterization of sub-Alfvénic turbulence energetics
Creators
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1.
California Institute of Technology
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2.
University of Crete
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3.
FORTH Institute of Astrophysics
Abstract
Magnetohydrodynamic (MHD) turbulence is a cross-field process relevant to many systems. A prerequisite for understanding these systems is to constrain the role of MHD turbulence, and in particular, the energy exchange between kinetic and magnetic forms. The energetics of strongly magnetized and compressible turbulence has so far resisted attempts to understand them. Numerical simulations reveal that kinetic energy can be orders of magnitude higher than fluctuating magnetic energy. We solved this lack-of-balance puzzle by calculating the energetics of compressible and sub-Alfvénic turbulence based on the dynamics of coherent cylindrical fluid parcels. Using the MHD Lagrangian, we proved analytically that the bulk of the magnetic energy transferred to kinetic energy is the energy that is stored in the coupling between the ordered and fluctuating magnetic field. The analytical relations are in strikingly good agreement with numerical data, up to second-order terms.
Additional Information
© The Authors 2023. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication. We would like to thank the anonymous referee for reviewing our manuscript. We are grateful to T. Ch. Mouschovias, and P. F. Hopkins for stimulating discussions. We also thank E. N. Economou, V. Pelgrims, E. Ntormousi, A. Tsouros, and I. Komis for useful suggestions on the manuscript. This work was supported by NSF grant AST-2109127. We acknowledge support by the European Research Council under the European Union's Horizon 2020 research and innovation programme, grant agreement No. 771282 (RS and KT); by the Hellenic Foundation for Research and Innovation under the "First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant", Project 1552 CIRCE (VP); and from the Foundation of Research and Technology – Hellas Synergy Grants Program (project MagMASim, VP, and project POLAR, KT).Attached Files
Published - aa46072-23.pdf
Files
aa46072-23.pdf
Additional details
Identifiers
- Eprint ID
- 121659
- Resolver ID
- CaltechAUTHORS:20230601-109410300.2
Funding
- NSF
- AST-2109127
- European Research Council (ERC)
- 771282
- Hellenic Foundation for Research and Innovation
- 1552 CIRCE
- Foundation of Research and Technology - Hellas
Dates
- Created
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2023-06-12Created from EPrint's datestamp field
- Updated
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2023-06-12Created from EPrint's last_modified field
Caltech Custom Metadata
- Caltech groups
- Owens Valley Radio Observatory