Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows
Abstract
We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from 0.02 to 20, we find significantly different magnetic field geometries, amplification rates, and saturation levels, decreasing strongly at the transition from subsonic to supersonic flows, due to the development of shocks. Both extreme types of turbulent forcing drive the dynamo, but solenoidal forcing is more efficient, because it produces more vorticity.
Keywords
Cite
@article{arxiv.1109.1760,
title = {Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows},
author = {Christoph Federrath and Gilles Chabrier and Jennifer Schober and Robi Banerjee and Ralf S. Klessen and Dominik R. G. Schleicher},
journal= {arXiv preprint arXiv:1109.1760},
year = {2011}
}
Comments
4 pages, 3 figures, published in Physical Review Letters (Phys. Rev. Lett. 107, 114504 (2011)), for more information and movies go to http://www.ita.uni-heidelberg.de/~chfeder/pubs/dynamo_prl/dynamo_prl.shtml?lang=en