Abstract
We present high-precision experimental and numerical studies of the Nusselt number as functions of the Rayleigh number in geostrophic rotating convection with the domain aspect ratio varying from 0.4 to 3.8 and the Ekman number varying from to . With decreasing our heat-transport data reveal a gradual transition from buoyancy-dominated to geostrophic convection at large , whereas the transition becomes sharp with decreasing . We determine the power-law scaling of , and find an unexpectedly strong dependence of the scaling exponent . We further show that the boundary flows formed near the lateral wall give rise to pronounced enhancement of over a broad range of the geostrophic regime, leading to reduction of in small- cells. A very steep scaling with is observed when the periodic lateral boundary condition is used, which manifests the significant differences between laterally confined and unconfined rotating thermal convection. The present work provides insight into the heat-transport scaling in geostrophic convection.
- Received 23 July 2020
- Revised 31 December 2020
- Accepted 12 July 2021
DOI:https://doi.org/10.1103/PhysRevFluids.6.L071501
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