Competition between Ekman Plumes and Vortex Condensates in Rapidly Rotating Thermal Convection.
Phys Rev Lett
; 125(21): 214501, 2020 Nov 20.
Article
en En
| MEDLINE
| ID: mdl-33274985
ABSTRACT
We perform direct numerical simulations of rotating Rayleigh-Bénard convection (RRBC) of fluids with low (Pr=0.1) and high (Pr≈5) Prandtl numbers in a horizontally periodic layer with no-slip bottom and top boundaries. No-slip boundaries are known to actively promote the formation of plumelike vertical disturbances, through so-called Ekman pumping, that control the ambient flow at sufficiently high rotation rates. At both Prandtl numbers, we demonstrate the presence of competing large-scale vortices (LSVs) in the bulk. Strong buoyant forcing and rotation foster the quasi-two-dimensional turbulent state of the flow that leads to the upscale transfer of kinetic energy that forms the domain-filling LSV condensate. The Ekman plumes from the boundary layers are sheared apart by the large-scale flow, yet we find that their energy feeds the upscale transfer. Our results of RRBC simulations substantiate the emergence of large-scale flows in nature regardless of the specific details of the boundary conditions.
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Colección:
01-internacional
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MEDLINE
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En
Revista:
Phys Rev Lett
Año:
2020
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Article
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Países Bajos