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-Coming silicone oil under the action of an applied temperature gradient in a reduced gravity environment aboard th e Space Shuttle in orbit. The disturbance of the imposed temperature field due to the motion of the objects was studied optically using a shearing int erferometer with a Wollaston prism and the results of aa typical bubble run were compared with theoretical predictions. Also, the liquid velocity fiel d surrounding the bubbles and drops has been qualitatively investigated in a few runs by the observation of tracer particles dispersed in the continuo us phase fluid. The measurement techniques are described, and the results f or the temperature and flow fields are presented and discussed.