The Library
2D enslaving of MHD turbulence
Tools
Nazarenko, Sergey (2007) 2D enslaving of MHD turbulence. New Journal of Physics, Vol.9 . Article: 307. doi:10.1088/1367-2630/9/8/307 ISSN 1367-2630.
Research output not available from this repository.
Request-a-Copy directly from author or use local Library Get it For Me service.
Official URL: http://dx.doi.org/10.1088/1367-2630/9/8/307
Abstract
At odds with its name, the classical weak turbulence theory only works for turbulence which is strong enough. Namely, the nonlinear resonance broadening has to be greater than the Fourier mode spacing Delta k = 2 pi/L, where L is the size of the bounding box. I will revise the wave turbulence theory by extending it to the finite-size systems and by generalizing the description, traditionally done for the energy spectra, to higher wave-mode moments and its probability density functions. I show that when the perturbations of the external magnetic field are so small that the nonlinear resonance broadening is smaller than the Fourier mode spacing, the finite k(parallel to) modes get slaved to the k(parallel to) = 0 modes. In other words, evolution in the perpendicular to the external field direction is identical to purely two-dimensional (2D) turbulence, whereas there is no evolution in the parallel direction, i.e. the parallel structure remains the same as in the initial condition (or forcing). In terms of the relative magnetic field perturbations, the condition of such a 2D enslaving is <(b)over-tilde/B-0 < sigma(2D) = 2 pi k(parallel to)(1/2)/(L-parallel to(1/2) k(perpendicular to)(2) L-perpendicular to). The classical weak turbulence works if k(perpendicular to) L-perpendicular to sigma(2D) < 2 pi k(parallel to)(1/2)/(L-parallel to(1/2) k(perpendicular to)) < (b)over-tilde/B-0 < 1. In the wide intermediate range of intensities sigma(2D) < (b)over-tilde/B-0 < k(perpendicular to) L-perpendicular to sigma(2D) turbulence has a mesoscopic nature such that the wave correlation time remains of the order of the inverse Fourier-mode spacing and independent on the wave amplitude. Both the 2D and the wave components are present in this regime and constancy of the wave correlation time hints at the possibility that the wave dynamics is linear.
Item Type: | Journal Article | ||||
---|---|---|---|---|---|
Subjects: | Q Science > QC Physics | ||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Mathematics | ||||
Journal or Publication Title: | New Journal of Physics | ||||
Publisher: | IOP Publishing | ||||
ISSN: | 1367-2630 | ||||
Official Date: | 31 August 2007 | ||||
Dates: |
|
||||
Volume: | Vol.9 | ||||
Number of Pages: | 14 | ||||
Page Range: | Article: 307 | ||||
DOI: | 10.1088/1367-2630/9/8/307 | ||||
Status: | Peer Reviewed | ||||
Publication Status: | Published | ||||
Access rights to Published version: | Open Access (Creative Commons) |
Data sourced from Thomson Reuters' Web of Knowledge
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |