Velocity field of thermocapillary convection in high-temperature oxide solution

We have investigated experimentally and theoretically the thermocapillary c onvective how phenomena in a loop-shaped Pt wire heater of KNbO3 (20wt.%) a nd Li2B4O7 solutions. Optical evaluations in connection with thermocouple m easurements made it possible to get a new type of thermocapillary convectiv e how in the considered system. To study the kinematical behaviour of therm ocapillary convection, we have measured the stream how velocities. In a the oretical analysis, the how velocity due to the thermocapillary effect alone was estimated by balancing the surface tension forces by viscous forces. T he velocity distribution in the solution near the margin of the heater was obtained, which is in agreement with the experimental result.