Main Page
About the Journal
Subscription information

Current Issue
Tables of Contents
Author Index
Search

Authors
Referees

Modeling anisotropic MHD turbulence in simulations of liquid metal flows

O. Widlund

Faxén Laboratory, Royal Institute of Technology SE-100 44, Stockholm, Sweden

Abstract
The dynamical properties of the MHD turbulence model proposed by Widlund etal. are examined for the case of homogeneous decaying turbulence. The model is a Reynolds stress closure, extended with a transport equation for a dimensional anisotropy variable, α, which carries information about length scale anisotropy. The analysis suggests that the model term originally proposed for the nonlinear energy transfer in the α equation should be modified. A unique set of model coefficients could be determined, which makes the model consistent with theory and experiments for interaction parameters N ranging from zero to infinity. The model coincides with the standard K-\eps model when there is no magnetic field. In the linear regime of large N, it produces the K ∼ t−1/2 energy decay predicted by linear theory. When nonlinear effects are important, the model predicts K ∼ t−1.7 and L||  ∼ t0.65, in agreement with the classical experiments by Alemany etal. Figs 5, Refs 11.

Magnetohydrodynamics 37, No. 1/2, 3-12, 2001 [PDF, 0.25 Mb]

Copyright: Institute of Physics, University of Latvia
ISSN (electronic edition): 1574-0579; ISSN (printed edition): 0024-998X