Sensitivity of the liquid bridge hydrodynamics to local capillary contributions

International audienceIn the usual models of thermocapillary flows, a vorticity singularity occurs at the contact free surface-solid boundaries. The steady axisymmetric hydrodynamics of the side-heated liquid bridge of molten metal is addressed here for its sensitivity to the size delta of a length scale explicitly introduced to regularize the problem. By linear stability analysis of the flows, various stable steady states are predicted: The already known steady states which are reflection-symmetric about the mid-plane, but also others which do not possess this property. The thresholds in Ma of the associated bifurcations are strongly dependent on delta, and converge with delta-->0 towards low values. Published data give these results some physical relevance. (C) 2002 American Institute of Physics

Solutions multiples thermocapillaires en zone flottante à gravité nulle

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Stability of the axisymmetric buoyant-capillary flows in a laterally heated liquid bridge

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Numerical study of convection induced by evaporation in cylindrical geometry

International audienceNumerical simulations of convection induced by solvent evaporation during the drying of a polymer solution are considered. This paper focuses on the transient thermal regime occurring at the beginning of the drying and transient solutal effects are not taken into account. The onset of convection (B'enard-Marangoni and Rayleigh-B'enard) is studied for a large range of initial thicknesses and viscosities. Several stochastic models are compared to analyze the influence of the perturbation description on the transition thresholds. Two-dimensional (2D) and three-dimensinal (3D) models are shown to give close results. The 3D model is used to characterize the pattern evolution during the drying. In the case of surface tension driven convection, a method is developed to describe the cells morphology and their time evolution

Etude numérique du régime transitoire dans un modèle thermique d'évaporation

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