Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-06-28
Astrophys. J. 741, 92 (2011)
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
7 pages, 6 figures, ApJ, in print
Scientific paper
10.1088/0004-637X/741/2/92
Saturated small-scale dynamo solutions driven by isotropic non-helical turbulence are presented at low magnetic Prandtl numbers Pm down to 0.01. For Pm < 0.1, most of the energy is dissipated via Joule heat and, in agreement with earlier results for helical large-scale dynamos, kinetic energy dissipation is shown to diminish proportional to Pm^{1/2} down to values of 0.1. In agreement with earlier work, there is, in addition to a short Golitsyn k^{-11/3} spectrum near the resistive scale also some evidence for a short k^{-1} spectrum on larger scales. The rms magnetic field strength of the small-scale dynamo is found to depend only weakly on the value of Pm and decreases by about a factor of 2 as Pm is decreased from 1 to 0.01. The possibility of dynamo action at Pm=0.1 in the nonlinear regime is argued to be a consequence of a suppression of the bottleneck seen in the kinetic energy spectrum in the absence of a dynamo and, more generally, a suppression of kinetic energy near the dissipation wavenumber.
No associations
LandOfFree
Nonlinear small-scale dynamos at low magnetic Prandtl numbers does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nonlinear small-scale dynamos at low magnetic Prandtl numbers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear small-scale dynamos at low magnetic Prandtl numbers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-42074