Long, RS, Mound, JE orcid.org/0000-0002-1243-6915, Davies, CJ et al. (1 more author) (2020) Scaling behaviour in spherical shell rotating convection with fixed-flux thermal boundary conditions. Journal of Fluid Mechanics, 889. A7. ISSN 0022-1120
Abstract
Bottom-heated convection in rotating spherical shells provides a simple analogue for many astrophysical and geophysical fluid systems. We construct a database of 74 three-dimensional numerical convection models to investigate the scaling behaviour of seven diagnostics over a range of Ekman and Rayleigh numbers while using a Prandtl number of unity. Our configuration is chosen to model Earth’s core as defined by the fixed flux thermal boundary conditions, radius ratio of and a gravity profile that varies linearly with radius. The quantities of interest are the viscous and thermal boundary layer thickness, mean temperature gradient, mean interior temperature, Nusselt number, horizontal flow length scale, and Reynolds number. We find four parameter regimes characterised by different scaling behaviour. For and low the weakly nonlinear regime is characterised by a balance between viscous, Archimedean and Coriolis forces and the heat transfer is described by weakly nonlinear theory. At low and moderate , the rapidly rotating regime sees inertia take over from viscosity in the global force balance. In this regime the heat transfer scaling has increasing exponent with decreasing Ekman number and shows no saturation to the diffusion free scaling. At high and all the importance of the Coriolis force gradually decreases and all diagnostics continually change in the transitional regime before approaching the scaling behaviour of non-rotating convection.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s), 2020. Published by Cambridge University Press. This article has been published in a revised form in Journal of Fluid Mechanics https://doi.org/10.1017/jfm.2020.67. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. |
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) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Jan 2020 12:09 |
Last Modified: | 21 Aug 2020 00:38 |
Status: | Published |
Publisher: | Cambridge University Press |
Identification Number: | 10.1017/jfm.2020.67 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:155596 |