Nonlinear closures for scale separation in supersonic magnetohydrodynamic turbulence
dc.contributor.author | Grete, P | |
dc.contributor.author | Vlaykov, DG | |
dc.contributor.author | Schmidt, W | |
dc.contributor.author | Schleicher, DRG | |
dc.contributor.author | Federrath, C | |
dc.date.accessioned | 2020-01-14T14:02:56Z | |
dc.date.issued | 2015-02-24 | |
dc.description.abstract | Turbulence in compressible plasma plays a key role in many areas of astrophysics and engineering. The extreme plasma parameters in these environments, e.g. high Reynolds numbers, supersonic and super-Alfvenic flows, however, make direct numerical simulations computationally intractable even for the simplest treatment - magnetohydrodynamics (MHD). To overcome this problem one can use subgrid-scale (SGS) closures - models for the influence of unresolved, subgrid-scales on the resolved ones. In this work we propose and validate a set of constant coefficient closures for the resolved, compressible, ideal MHD equations. The SGS energies are modeled by Smagorinsky-like equilibrium closures. The turbulent stresses and the electromotive force (EMF) are described by expressions that are nonlinear in terms of large scale velocity and magnetic field gradients. To verify the closures we conduct a priori tests over 137 simulation snapshots from two different codes with varying ratios of thermal to magnetic pressure () and sonic Mach numbers (). Furthermore, we make a comparison to traditional, phenomenological eddy-viscosity and closures. We find only mediocre performance of the kinetic eddy-viscosity and closures, and that the magnetic eddy-viscosity closure is poorly correlated with the simulation data. Moreover, three of five coefficients of the traditional closures exhibit a significant spread in values. In contrast, our new closures demonstrate consistently high correlations and constant coefficient values over time and over the wide range of parameters tested. Important aspects in compressible MHD turbulence such as the bi-directional energy cascade, turbulent magnetic pressure and proper alignment of the EMF are well described by our new closures. | en_GB |
dc.description.sponsorship | University of Gottingen | en_GB |
dc.description.sponsorship | Deutsche Forschungsgemeinschaft (DFG) | en_GB |
dc.description.sponsorship | Australian Research Council (ARC) | en_GB |
dc.identifier.citation | Vol. 17, article 023070 | en_GB |
dc.identifier.doi | 10.1088/1367-2630/17/2/023070 | |
dc.identifier.grantnumber | SFB 963/1 | en_GB |
dc.identifier.grantnumber | DP130102078 | en_GB |
dc.identifier.grantnumber | DP150104329 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/40412 | |
dc.language.iso | en | en_GB |
dc.publisher | IOP Publishing for Deutsche Physikalische Gesellschaft | en_GB |
dc.rights | © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Open access. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. | en_GB |
dc.subject | magnetohydrodynamics | en_GB |
dc.subject | turbulence | en_GB |
dc.subject | subgrid-scale closure | en_GB |
dc.subject | scale separation | en_GB |
dc.title | Nonlinear closures for scale separation in supersonic magnetohydrodynamic turbulence | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2020-01-14T14:02:56Z | |
dc.identifier.issn | 1367-2630 | |
dc.description | This is the final version. Available on open access from IOP Publishing via the DOI in this record | en_GB |
dc.identifier.journal | New Journal of Physics | en_GB |
dc.rights.uri | https://creativecommons.org/licenses/by/3.0/ | en_GB |
dcterms.dateAccepted | 2015-01-26 | |
rioxxterms.version | VoR | en_GB |
rioxxterms.licenseref.startdate | 2015-02-24 | |
rioxxterms.type | Journal Article/Review | en_GB |
refterms.dateFCD | 2020-01-14T13:59:46Z | |
refterms.versionFCD | VoR | |
refterms.dateFOA | 2020-01-14T14:03:10Z | |
refterms.panel | B | en_GB |
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Except where otherwise noted, this item's licence is described as © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Open access. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.