Heat convection in a vertical channel : Plumes versus turbulent diffusion

Abstract : Following a previous study [Gibert , Phys. Rev. Lett. 96, 084501 (2006)], convective heat transfer in a vertical channel of moderate dimensions follows purely inertial laws. It would be therefore a good model for convective flows of stars and ocean. Here we report new measurements on this system. We use an intrinsic length in the definition of the characteristic Rayleigh and Reynolds numbers. We explicit the relation between this intrinsic length and the thermal correlation length. Using particle imaging velocimetry, we show that the flow undergoes irregular reversals. We measure the average velocity profiles and the Reynolds stress tensor components. The momentum flux toward the vertical walls seems negligible compared to the shear turbulent stress. A mixing length theory seems adequate to describe the horizontal turbulent heat and momentum fluxes, but fails for the vertical ones. We propose a naive model for vertical heat transport inspired by the Knudsen regime in gases.
Liste complète des métadonnées

Littérature citée [16 références]  Voir  Masquer  Télécharger

https://hal-ens-lyon.archives-ouvertes.fr/ensl-00377244
Contributeur : Mathieu Gibert <>
Soumis le : mardi 21 avril 2009 - 16:27:33
Dernière modification le : lundi 22 octobre 2018 - 12:46:08
Document(s) archivé(s) le : jeudi 10 juin 2010 - 21:17:57

Fichier

Physics_of_Fluids_2009_Gibert_...
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Mathieu Gibert, Hervé Pabiou, Jean-Christophe Tisserand, Betina Gertjerenken, Bernard Castaing, et al.. Heat convection in a vertical channel : Plumes versus turbulent diffusion. Physics of Fluids, American Institute of Physics, 2009, 21 (3), pp.035109. 〈10.1063/1.3085812〉. 〈ensl-00377244〉

Partager

Métriques

Consultations de la notice

192

Téléchargements de fichiers

216