Isotropization at small scales of rotating helically driven turbulence

AMS Citation:
Mininni, P. D., D. L. Rosenberg, and A. Pouquet, 2012: Isotropization at small scales of rotating helically driven turbulence. Journal of Fluid Mechanics, 699, 263-279, doi:10.1017/jfm.2012.99.
Date:2012-05-01
Resource Type:article
Title:Isotropization at small scales of rotating helically driven turbulence
Abstract: We present numerical evidence of how three-dimensionalization occurs at small scale in rotating turbulence with Beltrami (ABC) forcing, creating helical flow. The Zeman scale lΩ at which the inertial and eddy turn-over times are equal is more than one order of magnitude larger than the dissipation scale, with the relevant domains (large-scale inverse cascade of energy, dual regime in the direct cascade of energy E and helicity H, and dissipation) each moderately resolved. These results stem from the analysis of a large direct numerical simulation on a grid of 3072³ points, with Rossby and Reynolds numbers, respectively, equal to 0.07 and 2.7 x 10⁴. At scales smaller than the forcing, a helical wave-modulated inertial law for the energy and helicity spectra is followed beyond lΩ ; by Kolmogorov spectra for E and H. Looking at the two-dimensional slow manifold, we also show that the helicity spectrum breaks down at lΩ ;, a clear sign of recovery of three-dimensionality in the small scales.
Subject(s):Isotropic turbulence;, Rotating turbulence, Wave–turbulence interactions
Peer Review:Refereed
Copyright Information:Copyright 2012 Cambridge University Press.
OpenSky citable URL: ark:/85065/d7c53mhk
Publisher's Version: 10.1017/jfm.2012.99
Author(s):
  • Pablo Mininni - NCAR/UCAR
  • Duane Rosenberg - NCAR/UCAR
  • Annick Pouquet - NCAR/UCAR
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