Eddy viscosity and laminarization of sheared flow in three dimensional reduced magnetohydrodynamic turbulence

Eun Jin Kim, T. S. Hahm, P. H. Diamond

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The effect of Alfvén waves on turbulent momentum transport is studied in three-dimensional reduced magnetohydrodynamic turbulence. A strong external uniform magnetic field B0 is assumed to be present orthogonal to both background shear flow and its inhomogeneity. Energy is injected into the fluid and/or magnetic field on small scales. It is shown analytically that eddy viscosity is reduced as 1/B20 for a strong B0, due to the cancellation of the Reynolds stress by Maxwell stress. The sign of eddy viscosity is found to depend on the detailed properties of forcings. Specifically, it is positive for fluid forcing but depends on the anisotropy of the forcing in the case of magnetic forcing. Furthermore, it is indicated that a magnetic field tends to laminarize a mean shear flow. The possible implication of these results for the dynamics of the zonal flows in tokamaks is discussed in view of the cancellation of stresses.

Original languageEnglish
Pages (from-to)3576-3582
Number of pages7
JournalPhysics of Plasmas
Volume8
Issue number8
DOIs
Publication statusPublished - 18 Jul 2001
Externally publishedYes

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magnetohydrodynamic turbulence
eddy viscosity
shear flow
cancellation
magnetic fields
fluids
Reynolds stress
inhomogeneity
momentum
anisotropy
energy

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Eddy viscosity and laminarization of sheared flow in three dimensional reduced magnetohydrodynamic turbulence. / Kim, Eun Jin; Hahm, T. S.; Diamond, P. H.

In: Physics of Plasmas, Vol. 8, No. 8, 18.07.2001, p. 3576-3582.

Research output: Contribution to journalArticle

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