Thermocapillary deformation in a locally heated layer of silicone oil

The processes of heat and mass transfer in systems with liquid-gas interface are of interest to a wide range of problems. Thermocapillary flows have an important role in such systems. Thermocapillary deformation of silicone oil layer was investigated using laser scanning confocal microscope Zeiss LSM 510 Meta. The numerical solution of the problem was obtained in the lubrication approximation theory for two-dimensional axisymmetric thermocapillary flow. The model takes into account the surface tension, viscosity, gravity and heat transfer in the substrate. Evaporation is neglected. The numerical algorithm for the joint solution of the energy equation and the evolution equation for the liquid layer thickness has been developed. Stationary solutions have been obtained by the establishment method. The dependences of the depth of thermocapillary deformation on the layer thickness were obtained for silicone oils of different viscosities. It was found that the value of the relative deformation decreases nonlinearly with increasing the initial layer thickness. There is a good qualitative agreement of numerical results and experimental data. (paper)