Heat-transport scaling and transition in geostrophic rotating convection with varying aspect ratio Article Swipe
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· 2021
· Open Access
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· DOI: https://doi.org/10.1103/physrevfluids.6.l071501
· OA: W3044112758
We present high-precision experimental and numerical studies of the Nusselt\nnumber $Nu$ as functions of the Rayleigh number $Ra$ in geostrophic rotating\nconvection with domain aspect ratio ${\\Gamma}$ varying from 0.4 to 3.8 and the\nEkman number Ek from $2.0{\\times}10^{-7}$ to $2.7{\\times}10^{-5}$. The\nheat-transport data $Nu(Ra)$ reveal a gradual transition from\nbuoyancy-dominated to geostrophic convection at large $Ek$, whereas the\ntransition becomes sharp with decreasing $Ek$. We determine the power-law\nscaling of $Nu{\\sim}Ra^{\\gamma}$, and show that the boundary flows give rise to\npronounced enhancement of $Nu$ in a broad range of the geostrophic regime,\nleading to reduction of the scaling exponent ${\\gamma}$ in small ${\\Gamma}$\ncells. The present work provides new insight into the heat-transport scaling in\ngeostrophic convection and may explain the discrepancies observed in previous\nstudies.\n
