Correlations and Cascades in Magnetized Turbulence

doi:10.1109/TPS.2019.2891934

Title: Correlations and Cascades in Magnetized Turbulence

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Abstract

Many terrestrial and astrophysical plasmas encompass very large dynamical ranges in space and time, which are not accessible by direct numerical simulations. Thus, idealized subvolumes are often used to study small-scale effects including the dynamics of magnetized turbulence. A significant aspect of magnetized turbulence is the transfer of energy from large to small scales, in part through the operation of a turbulent cascade. In this work, we present a new shell-to-shell energy transfer analysis framework for understanding energy transfer within magnetized turbulence and in particular, through the cascade. We demonstrate the viability of this framework through application to a series of isothermal subsonic and supersonic simulations of compressible magnetized turbulence and utilize results from this analysis to establish a non-linear benchmark for compressible magnetized turbulence in the subsonic regime. We further study how the autocorrelation time of the driving and its normalization systematically change properties of compressible magnetized turbulence. For example, we find that 6-in-time forcing with a constant energy injection leads to a steeper slope in kinetic energy spectrum and less efficient small-scale dynamo action. We examine how these results can impact a range of diagnostics relevant for a range of terrestrial and astrophysical applications.

Authors:

^[1]; Grete, Philipp ^[2]; O'Shea, Brian W. ^[2]

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Michigan State Univ., East Lansing, MI (United States)

Publication Date:: 2019-02-13

Research Org.:: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:: 1498478

Report Number(s):: [SAND-2019-0075J]
[Journal ID: ISSN 0093-3813; 671308]

Grant/Contract Number:: [AC04-94AL85000]

Resource Type:: Accepted Manuscript

Journal Name:: IEEE Transactions on Plasma Science

Additional Journal Information:: [Journal Name: IEEE Transactions on Plasma Science]; Journal ID: ISSN 0093-3813

Publisher:: IEEE

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; astrophysics; plasma devices; plasma simulation

Citation Formats


                    Beckwith, Kris, Grete, Philipp, and O'Shea, Brian W. Correlations and Cascades in Magnetized Turbulence.  United States: N. p., 2019. 
        Web.  doi:10.1109/TPS.2019.2891934.

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                    Beckwith, Kris, Grete, Philipp, & O'Shea, Brian W. Correlations and Cascades in Magnetized Turbulence.  United States.  doi:10.1109/TPS.2019.2891934.

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                    Beckwith, Kris, Grete, Philipp, and O'Shea, Brian W. Wed .  
        "Correlations and Cascades in Magnetized Turbulence".  United States.  doi:10.1109/TPS.2019.2891934.  https://www.osti.gov/servlets/purl/1498478.

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@article{osti_1498478,

  title        = {Correlations and Cascades in Magnetized Turbulence},

  author       = {Beckwith, Kris and Grete, Philipp and O'Shea, Brian W.},

  abstractNote = {Many terrestrial and astrophysical plasmas encompass very large dynamical ranges in space and time, which are not accessible by direct numerical simulations. Thus, idealized subvolumes are often used to study small-scale effects including the dynamics of magnetized turbulence. A significant aspect of magnetized turbulence is the transfer of energy from large to small scales, in part through the operation of a turbulent cascade. In this work, we present a new shell-to-shell energy transfer analysis framework for understanding energy transfer within magnetized turbulence and in particular, through the cascade. We demonstrate the viability of this framework through application to a series of isothermal subsonic and supersonic simulations of compressible magnetized turbulence and utilize results from this analysis to establish a non-linear benchmark for compressible magnetized turbulence in the subsonic regime. We further study how the autocorrelation time of the driving and its normalization systematically change properties of compressible magnetized turbulence. For example, we find that 6-in-time forcing with a constant energy injection leads to a steeper slope in kinetic energy spectrum and less efficient small-scale dynamo action. We examine how these results can impact a range of diagnostics relevant for a range of terrestrial and astrophysical applications.},

  doi          = {10.1109/TPS.2019.2891934},

  journal      = {IEEE Transactions on Plasma Science},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {2019},

  month        = {2}

}

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