Journal
JOURNAL OF FLUID MECHANICS
Volume 657, Issue -, Pages 502-538Publisher
CAMBRIDGE UNIV PRESS
DOI: 10.1017/S0022112010001795
Keywords
MHD turbulence
Categories
Funding
- EURYI
- EC
- Communaute Francaise de Belgique [ARC 02/07-283]
- EURATOM-Belgian state
Ask authors/readers for more resources
We report a detailed numerical investigation of homogeneous decaying turbulence in an electrically conducting fluid in the presence of a uniform constant magnetic field. The asymptotic limit of low magnetic Reynolds number is assumed. Large-eddy simulations with the dynamic Smagorinsky model are performed in a computational box sufficiently large to minimize the effect of periodic boundary conditions. The initial microscale Reynolds number is about 170 and the magnetic interaction parameter N varies between 0 and 50. We find that except for a short period of time when N = 50, the flow evolution is strongly influenced by nonlinearity and cannot be adequately described by any of the existing theoretical models. One particularly noteworthy result is the near equipartition between the rates of Joule and viscous dissipations of the kinetic energy observed at all values of N during the late stages of the decay. Further, the velocity components parallel and perpendicular to the magnetic field decay at different rates, whose value depends on the strength of the magnetic field and the stage of the decay. This leads to a complex evolution of the Reynolds stress anisotropy ellipsoid, which goes from being rod-shaped, through spherical to disc-shaped. We also discuss the possibility of the power-law decay, the comparison between computed, experimental and theoretical decay exponents, the anisotropy of small-scale fluctuations, and the evolution of the spectral energy distributions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available