Prandtl and Rayleigh number dependence of heat transport in high Rayleigh number thermal convection
Keyword(s):
AbstractResults from direct numerical simulation for three-dimensional Rayleigh–Bénard convection in samples of aspect ratio $\Gamma = 0. 23$ and $\Gamma = 1/ 2$ up to Rayleigh number $\mathit{Ra}= 2\ensuremath{\times} 1{0}^{12} $ are presented. The broad range of Prandtl numbers $0. 5\lt \mathit{Pr}\lt 10$ is considered. In contrast to some experiments, we do not see any increase in $\mathit{Nu}/ {\mathit{Ra}}^{1/ 3} $ with increasing $\mathit{Ra}$, neither due to an increasing $\mathit{Pr}$, nor due to constant heat flux boundary conditions at the bottom plate instead of constant temperature boundary conditions. Even at these very high $\mathit{Ra}$, both the thermal and kinetic boundary layer thicknesses obey Prandtl–Blasius scaling.
Keyword(s):
1996 ◽
Vol 326
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pp. 399-415
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Keyword(s):
2012 ◽
Vol 96
(1)
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pp. 97-103
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2009 ◽
Vol 36
(10)
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pp. 1103
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2004 ◽
Vol 2004
(19)
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pp. 991-1001
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