Thermocapillary convection in liquid-in-liquid capillary bridges due to a heating/cooling ring

A liquid bridge connecting two solid disks is surrounded by a heating/cooling ring in the presence of another immiscible liquid. The thermocapillary convection and the interface deformation thus generated in a gravitational environment are studied for a range of bridge aspect ratios and ring temperatures using 2D axisymmetric simulations. A stark difference between the heater and cooler cases is observed in their flow and heat transfer patterns. Interfacial velocity and bridge deformation are seen to be more stable when a cooling ring surrounds the liquid bridge. Fluid trajectories inside the bridge show longer paths as the temperature difference between the cooler/heater and the surroundings is raised. Moreover, a cooler lessens the deformation, whereas a heater enhances the deformation of the phase interface. Anomalous results for a heat transfer rate, interface deformation, and circulation patterns are obtained in the heater configuration for larger height to radius ratios.

Automated summary

This study investigates the thermocapillary convection and interface deformation of a liquid bridge surrounded by a heating/cooling ring in the presence of another immiscible liquid under the influence of gravity through 2D axisymmetric simulations. The results show that there is a significant difference in flow and heat transfer patterns between the heating and cooling cases. The interfacial velocity and bridge deformation are more stable when a cooling ring surrounds the liquid bridge. Moreover, a cooling ring reduces deformation, while a heating ring enhances interface deformation.