THERMOCAPILLARY CONVECTION AROUND A HORIZONTAL HEAT SOURCE IN A LIQUID CAVITY

摘要

Numerical and experimental studies are performed on thermal fluid-flow transport phenomena around a heating wire set on the free surface of a liquid cavity. Emphasis is placed on the effects of the Marangoni number, Ma, the aspect ratio, H/L, and the Rayleigh number, Ra, on the flow and isothermal fields. The mechanism is theoretically investigated by numerically solving the two-dimensional governing equations through discretization by means of a finite-difference technique. Experimentally, flow patterns are disclosed by means of a tracer method. It is found that (ⅰ) the thermal fluid flow is affected by the aspect ratio, that is the thermal fluid flow in the lower region of the cavity with H/L = 2 is almost stable, and (ⅱ) natural convection around the wire is induced by the Marangoni force, i.e., the surface tension, while the effect of Ra on the velocity field is minor.