Issue
EPL
Volume 81, Number 6, March 2008
Article Number 64008
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/81/64008
Published online 07 March 2008
EPL, 81 (2008) 64008
DOI: 10.1209/0295-5075/81/64008

Numerical simulations of flow reversal in Rayleigh-Bénard convection

R. Benzi1 and R. Verzicco2

1  Dipartimento di Fisica and INFN, Università di Roma "Tor Vergata" - Via della Ricerca Scientifica 1, 00133 Rome, Italy
2  Dipartimento di Ingegneria Meccanica, Università di Roma "Tor Vergata" - Via del Politecnico 1, 00133 Rome, Italy


received 13 August 2007; accepted in final form 28 January 2008; published March 2008
published online 7 March 2008

Abstract
We investigate numerically the statistical properties of the large-scale flow in Rayleigh-Bénard convection. By using an external random perturbation on the temperature field, we were able to decrease the effective Prandtl number of the flow while keeping the Rayleigh number relatively small; this increases the Reynolds number thus making possible the numerical investigation of the long-term flow statistics. We also propose a simple and quantitative explanation for the experimental findings on the statistical distribution of flow reversals and reorientations.

PACS
47.27.-i - Turbulent flows.
05.45.-a - Nonlinear dynamics and chaos.
47.55.P- - Buoyancy-driven flows; convection.

© EPLA 2008