Authors
JJ Niemela, L Skrbek, KR Sreenivasan, RJ Donnelly
Publication date
2000/4/20
Journal
Nature
Volume
404
Issue
6780
Pages
837-840
Publisher
Nature Publishing Group UK
Description
Turbulent convection occurs when the Rayleigh number (Ra)—which quantifies the relative magnitude of thermal driving to dissipative forces in the fluid motion—becomes sufficiently high. Although many theoretical and experimental studies of turbulent convection exist, the basic properties of heat transport remain unclear. One important question concerns the existence of an asymptotic regime that is supposed to occur at very high Ra. Theory predicts that in such a state the Nusselt number (Nu), representing the global heat transport, should scale as Nu ∝ Raβ with β = 1/2. Here we investigate thermal transport over eleven orders of magnitude of the Rayleigh number (106 ≤ Ra ≤ 1017), using cryogenic helium gas as the working fluid. Our data, over the entire range of Ra, can be described to the lowest order by a single power-law with scaling exponent β close to 0.31. In particular, we find no evidence …
Total citations
Scholar articles
JJ Niemela, L Skrbek, KR Sreenivasan, RJ Donnelly - Nature, 2000
JJ Niemela, L Skrbek, KR Sreenivasan, RJ Donnelly - Nature, 2000