Influence of Thermocapillary Flow in a Liquid Film Jet

The higher temperature liquid (or melt) film ejected from a vessel and painted on the moving solid boundary is analyzed. The thermocapillary flow, driven by the gradient of surface tension on the free surface of a liquid film, changes the height profile of the liquid film. Based on the approximations of lubrication theory and perturbation theory, the equation of liquid height and the process of thermal hydrodynamics in the liquid film are solved for a given temperature distribution on the solid boundary and a given heat flux from the vessel. The solution shows clearly the obvious influence of the thermocapillary flow on the thermal hydrodynamic process and the cross-section profile of the liquid film even for a Newtonian fluid. The results may be used to explain the Barus effect or the Die Swell effect