Abstract
We present an analysis of the anisotropic spectral energy distribution in incompressible magnetohydrodynamic turbulence permeated by a strong mean magnetic field. The turbulent flow is generated by high-resolution pseudospectral direct numerical simulations with large-scale isotropic forcing. Examining the radial energy distribution for various angles with respect to reveals a specific structure which remains hidden when not taking axial symmetry with respect to into account. For each direction, starting at the forced large scales, the spectrum first exhibits an amplitude drop around a wave number which marks the start of a scaling range and goes on up to a dissipative wave number . The three-dimensional spectrum for is described by a single -independent functional form , with the scaling law being the same in every direction. The previous properties still hold when increasing the mean field from up to , as well as when passing from resistive to ideal flows. We conjecture that at fixed the direction-independent scaling regime is reached when increasing the Reynolds number above a threshold which raises with increasing . Below that threshold critically balanced turbulence is expected.
- Received 31 July 2009
DOI:https://doi.org/10.1103/PhysRevE.82.026406
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