Thermocapillary convection in a spherical drop partly attached to a spherical wall

Abstract

For a liquid globule, partly captured in spherical caps of different meridian angles the thermo-capillary flow has been determined due to the change of temperature on the liquid surface. The variation of the applied temperature on the liquid surface causes a variation of the surface tension and therefore a tangential force moving from warm to cold. The streamlines are presented for linear and quadratic temperature distribution on the liquid surface. As the cap angle α increases the center of the ring vortex moves down and towards the free liquid surface. In addition the flow exhibits with increasing magnitude of cap coverage a reduced velocity distribution. For a quadratic temperature distribution the existence of two opposite vortex rings are shown for α<π/2. The upper vortex ring disappears as α becomes larger than π/2. In addition we notice the shift of the vortex core towards the free surface and bottom of the drop.