Mean wind and its reversal in thermal convection

K. R. Sreenivasan, A. Bershadskii, J. J. Niemela

Research output: Contribution to journalArticle

Abstract

Properties of the mean wind in thermal convection, especially the abrupt reversal of its direction at high Rayleigh numbers, are studied. Measurements made in a closed cylindrical container of aspect ratio 1 are analyzed, and both the long-term and short-term behaviors of the direction reversals are discussed. A first look at the data suggests a Brownian-type process in action, but a closer look suggests the existence of hierarchical features with time scales extending roughly over a decade and a half. A physical model consistent with experimental observations is presented, and the origin of the cutoff scales is discussed. It appears that the generation of the wind as well as the reversal of its direction can be understood in terms of the imbalance between buoyancy effects and friction.

Original languageEnglish (US)
Number of pages1
JournalPhysical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
Volume65
Issue number5
DOIs
StatePublished - Jan 1 2002

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Thermal Convection
Reversal
free convection
Rayleigh number
Buoyancy
Physical Model
Container
containers
buoyancy
Aspect Ratio
aspect ratio
Friction
Time Scales
friction
cut-off
Closed

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

Cite this

Mean wind and its reversal in thermal convection. / Sreenivasan, K. R.; Bershadskii, A.; Niemela, J. J.

In: Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Vol. 65, No. 5, 01.01.2002.

Research output: Contribution to journalArticle

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