Heat transport scaling and transition in geostrophic rotating convection with varying aspect ratio
| Autor: | Hao-Yuan Lu, Jin-Qiang Zhong, Ke-Qing Xia, Jun-Qiang Shi, Guang-Yu Ding |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Convection Aspect ratio Enhanced heat transfer Fluid Dynamics (physics.flu-dyn) Computational Mechanics FOS: Physical sciences Boundary (topology) Physics - Fluid Dynamics Domain (mathematical analysis) Geophysics (physics.geo-ph) Computational physics Physics::Fluid Dynamics Physics - Geophysics Modeling and Simulation Scaling Geostrophic wind Physics::Atmospheric and Oceanic Physics Convection cell |
| Popis: | We present high-precision experimental and numerical studies of the Nusselt number $Nu$ as functions of the Rayleigh number $Ra$ in geostrophic rotating convection with domain aspect ratio ${\Gamma}$ varying from 0.4 to 3.8 and the Ekman number Ek from $2.0{\times}10^{-7}$ to $2.7{\times}10^{-5}$. The heat-transport data $Nu(Ra)$ reveal a gradual transition from buoyancy-dominated to geostrophic convection at large $Ek$, whereas the transition becomes sharp with decreasing $Ek$. We determine the power-law scaling of $Nu{\sim}Ra^{\gamma}$, and show that the boundary flows give rise to pronounced enhancement of $Nu$ in a broad range of the geostrophic regime, leading to reduction of the scaling exponent ${\gamma}$ in small ${\Gamma}$ cells. The present work provides new insight into the heat-transport scaling in geostrophic convection and may explain the discrepancies observed in previous studies. Comment: 5 pages, 4 figures, 1 table |
| Databáze: | OpenAIRE |
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