Pizzi, F, Mamatsashvili, G, Barker, AJ orcid.org/0000-0003-4397-7332 et al. (2 more authors) (2022) Interplay between geostrophic vortices and inertial waves in precession-driven turbulence. Physics of Fluids, 34 (12). 125135. ISSN 1070-6631
Abstract
The properties of rotating turbulence driven by precession are studied using direct numerical simulations and analysis of the underlying dynamical processes in Fourier space. The study is carried out in the local rotating coordinate frame, where precession gives rise to a background shear flow, which becomes linearly unstable and breaks down into turbulence. We observe that this precession-driven turbulence is in general characterized by coexisting two-dimensional (2D) columnar vortices and three-dimensional (3D) inertial waves, whose relative energies depend on the precession parameter Po. The vortices resemble the typical condensates of geostrophic turbulence, are aligned along the rotation axis (with zero wavenumber in this direction, kz = 0), and are fed by the 3D waves through nonlinear transfer of energy, while the waves (with kz≠0) in turn are directly fed by the precessional instability of the background flow. The vortices themselves undergo inverse cascade of energy and exhibit anisotropy in Fourier space. For small Po < 0.1 and sufficiently high Reynolds numbers, the typical regime for most geo- and astrophysical applications, the flow exhibits strongly oscillatory (bursty) evolution due to the alternation of vortices and small-scale waves. On the other hand, at larger Po > 0.1 turbulence is quasi-steady with only mild fluctuations, the coexisting columnar vortices and waves in this state give rise to a split (simultaneous inverse and forward) cascade. Increasing the precession magnitude causes a reinforcement of waves relative to vortices with the energy spectra approaching the Kolmogorov scaling, and therefore, the precession mechanism counteracts the effects of the rotation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 Author(s). This is an author produced version of an article published in Physics of Fluids. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Funding Information: | Funder Grant number STFC (Science and Technology Facilities Council) ST/W000873/1 STFC (Science and Technology Facilities Council) ST/S000275/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Dec 2022 12:21 |
Last Modified: | 21 Jan 2023 01:17 |
Status: | Published |
Publisher: | American Institute of Physics |
Identification Number: | 10.1063/5.0131035 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:193946 |