Kinematic regimes of convection at high Prandtl number in a shallow cavity

Jean-Marc Flesselles (1) , Franck Pigeonneau (1)

1 SGR - Saint-Gobain Recherche

We consider free convection in a horizontal shallow cavity with different end temperatures, filled with a high Prandtl number fluid. From scaling analysis, we find two kinematic regimes resulting from the competition of heat transfer by conduction and by convection. Numerical simulations realized for a large range of Rayleigh number and aspect ratio confirm the phenomenological analysis and provide the threshold between the two regimes. The conductive and convective regimes occur at RaA^2 smaller and larger than 443 respectively, where Ra is the Rayleigh number and A is the aspect ratio. In the convective regime, the characteristic velocity is independent of depth of the cavity.

Mots clés: Fluid mechanics; Natural convection; High Prandtl number fluid

Mots clés: Convection naturelle; Haut nombre de Prandtl

Domaines: Mécanique des fluides [physics.class-ph]

Jean-Marc Flesselles, Franck Pigeonneau. Kinematic regimes of convection at high Prandtl number in a shallow cavity. Comptes Rendus Mécanique, 2004, 332 (10), pp.783-788. ⟨10.1016/S1631-0721(04)00156-1⟩. ⟨hal-01442932⟩