Thermocapillary migration of bubbles and drops at moderate to large Marangoni number and moderate Reynolds number in reduced gravity

Results from experiments on the thermocapillary migration of air bubbles an d Fluorinert drops in a Dow-Coming silicone oil aboard a NASA Space Shuttle mission are presented and discussed. The experiments cover a wider range o f Marangoni and Reynolds numbers than that attained in a prior flight exper iment. The data are consistent with earlier results, and are compared with theoretical predictions. Large air bubbles were found to deform slightly in shape to oblate spheroids while the deformation of even the largest drops was within the uncertainty of the size measurements.