Thermocapillary flows in a drop with unsteady spot heating in a microgravity environment

The unsteady localized spot heating of a liquid clr-op lu?ner zero-g conditions is examined theoretically. This pertains to space experiments to measure thermal properties of materials and the purpose here is to predict the thermal behavior of such systems. Spot heating can be achieved by a laser beam focused on a small legion of the drop surface. The present theoretical model deals with situations of weak Marangoni flows, whereby the thermal transport is conduction-dominated. The heat flow in the drop is treated as unsteady while the surrounding gaseous region is considered to be quasi-steady. The ensuing thermally driven flow is analyzed in the Stokes regime.