Non-local energy transfers in rotating turbulence at intermediate Rossby number
Name
Bourouiba_Non-local energy.pdf
Size
997.51 KB
Format
Adobe PDF
Checksum (MD5)
4db00411f5e6558f764b28c73bdd888b
Author(s)
Straub, D. N.
Waite, M. L.
Bourouiba, Lydia
Date Issued
November 2011
Journal
Journal of Fluid Mechanics
Publisher
Cambridge University Press
Citation
Bourouiba, L., D. N. Straub, and M. L. Waite. “Non-Local Energy Transfers in Rotating Turbulence at Intermediate Rossby Number.” J. Fluid Mech. 690 (January 2012): 129–147. © Cambridge University Press
Version
Final published version
Abstract
Turbulent flows subject to solid-body rotation are known to generate steep energy spectra and two-dimensional columnar vortices. The localness of the dominant energy transfers responsible for the accumulation of the energy in the two-dimensional columnar vortices of large horizontal scale remains undetermined. Here, we investigate the scale-locality of the energy transfers directly contributing to the growth of the two-dimensional columnar structures observed in the intermediate Rossby number (Ro) regime. Our approach is to investigate the dynamics of the waves and vortices separately: we ensure that the two-dimensional columnar structures are not directly forced so that the vortices can result only from association with wave to vortical energy transfers. Detailed energy transfers between waves and vortices are computed as a function of scale, allowing the direct tracking of the role and scales of the wave–vortex nonlinear interactions in the accumulation of energy in the large two-dimensional columnar structures. It is shown that the dominant energy transfers responsible for the generation of a steep two-dimensional spectrum involve direct non-local energy transfers from small-frequency small-horizontal-scale three-dimensional waves to large-horizontal-scale two-dimensional columnar vortices. Sensitivity of the results to changes in resolution and forcing scales is investigated and the non-locality of the dominant energy transfers leading to the emergence of the columnar vortices is shown to be robust. The interpretation of the scaling law observed in rotating flows in the intermediate-Ro regime is revisited in the light of this new finding of dominant non-locality.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Massachusetts Institute of Technology. Department of Mathematics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1017/jfm.2011.387
