Small scale structures in three-dimensional magnetohydrodynamic turbulence

Mininni, P. D.; Pouquet, A.; Montgomery, D. C.

Small scale structures in three-dimensional magnetohydrodynamic turbulence

Authors

Mininni, P. D.

Pouquet, A.

Montgomery, D. C.

Description

We investigate using direct numerical simulations with grids up to 1536^3 points, the rate at which small scales develop in a decaying three-dimensional MHD flow both for deterministic and random initial conditions. Parallel current and vorticity sheets form at the same spatial locations, and further destabilize and fold or roll-up after an initial exponential phase. At high Reynolds numbers, a self-similar evolution of the current and vorticity maxima is found, in which they grow as a cubic power of time; the flow then reaches a finite dissipation rate independent of Reynolds number.
4 pages, 3 figures