TEMPERATURE FIELDS IN A LIQUID DUE TO THE THERMOCAPILLARY MOTION OF BUBBLES AND DROPS

Experiments were performed on the motion of isolated air bubbles and drops of Fluorinert FC-75 moving in a Dow-Corning silicone oil under the action of an applied temperature gradient in a reduced gravity environment aboard the Space Shuttle in orbit. We studied the disturbance of the imposed temperature field due to the motion of the objects optically using a shearing interferometer with a Wollaston prism. Also, the liquid velocity field surrounding the bubbles and drops has been qualitatively investigated in a few runs by the observation of tracer particles dispersed in the continuous phase fluid. We describe the applied measurement technique, and present and discuss the results for the temperature field and the flow field measurements.