Scale-locality of magnetohydrodynamic turbulence
Abstract
We investigate the scale-locality of cascades of conserved invariants at high kinetic and magnetic Reynolds numbers in the 'inertial-inductive range' of magnetohydrodynamic (MHD) turbulence, where velocity and magnetic field increments exhibit suitable power-law scaling. We prove that fluxes of total energy and cross-helicity - or, equivalently, fluxes of Elsaesser energies - are dominated by the contributions of local triads. Corresponding spectral transfers are also scale-local when defined using octave wavenumber bands. Flux and transfer of magnetic helicity may be dominated by nonlocal triads. The magnetic stretching term also may be dominated by non-local triads but we prove that it can convert energy only between velocity and magnetic modes at comparable scales. We explain the disagreement with numerical studies that have claimed conversion non locally between disparate scales. We present supporting data from a 1024{sup 3} simulation of forced MHD turbulence.
- Authors:
-
- Los Alamos National Laboratory
- JOHNS HOPKINS UNIV.
- Publication Date:
- Research Org.:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 971311
- Report Number(s):
- LA-UR-09-06199; LA-UR-09-6199
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US1001156
- DOE Contract Number:
- AC52-06NA25396
- Resource Type:
- Journal Article
- Journal Name:
- Physical Review Letters
- Additional Journal Information:
- Journal Name: Physical Review Letters; Journal ID: ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; HELICITY; KINETICS; MAGNETIC FIELDS; MAGNETIC REYNOLDS NUMBER; MAGNETOHYDRODYNAMICS; SIMULATION; TURBULENCE; VELOCITY
Citation Formats
Aluie, Hussein, and Eyink, Gregory L. Scale-locality of magnetohydrodynamic turbulence. United States: N. p., 2009.
Web.
Aluie, Hussein, & Eyink, Gregory L. Scale-locality of magnetohydrodynamic turbulence. United States.
Aluie, Hussein, and Eyink, Gregory L. 2009.
"Scale-locality of magnetohydrodynamic turbulence". United States. https://www.osti.gov/servlets/purl/971311.
@article{osti_971311,
title = {Scale-locality of magnetohydrodynamic turbulence},
author = {Aluie, Hussein and Eyink, Gregory L},
abstractNote = {We investigate the scale-locality of cascades of conserved invariants at high kinetic and magnetic Reynolds numbers in the 'inertial-inductive range' of magnetohydrodynamic (MHD) turbulence, where velocity and magnetic field increments exhibit suitable power-law scaling. We prove that fluxes of total energy and cross-helicity - or, equivalently, fluxes of Elsaesser energies - are dominated by the contributions of local triads. Corresponding spectral transfers are also scale-local when defined using octave wavenumber bands. Flux and transfer of magnetic helicity may be dominated by nonlocal triads. The magnetic stretching term also may be dominated by non-local triads but we prove that it can convert energy only between velocity and magnetic modes at comparable scales. We explain the disagreement with numerical studies that have claimed conversion non locally between disparate scales. We present supporting data from a 1024{sup 3} simulation of forced MHD turbulence.},
doi = {},
url = {https://www.osti.gov/biblio/971311},
journal = {Physical Review Letters},
issn = {0031-9007},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 2009},
month = {Thu Jan 01 00:00:00 EST 2009}
}