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Plume motion and large-scale circulation in a cylindrical Rayleigh-Bénard cell

Denis Funfschilling·Guenter Ahlers
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Abstract

We used the time correlation of shadowgraph images to determine the angle $Θ$ of the horizontal component of the plume velocity above (below) the center of the bottom (top) plate of a cylindrical Rayleigh-Bénard cell of aspect ratio $Γ\equiv D/L = 1$ ($D$ is the diameter and $L \simeq 87$ mm the height) in the Rayleigh-number range $7\times 10^7 \leq R \leq 3\times 10^{9}$ for a Prandtl number $σ= 6$. We expect that $Θ$ gives the direction of the large-scale circulation. It oscillates time-periodically. Near the top and bottom plates $Θ(t)$ has the same frequency but is anti-correlated.

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Denis Funfschilling, Guenter Ahlers. 2004-02-22. Plume motion and large-scale circulation in a cylindrical Rayleigh-Bénard cell. https://doi.org/10.1103/physrevlett.92.194502

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