Numerical Simulation of Thermocapillary Drop Motion with Internal Circulation

The thermocapillary motion of drops in zero gravity is analyzed numerically. When convective transport is important, the internal circulation in the drop has a profound effect on the temperature distribution in its vicinity and hence on its migration speed. For sufficiently large values of the Marangoni number number Ma, for steady motion of the drop, the temperature difference on the drop surface and its scaled speed increase with Ma. This is in contrast to (1) existing computational results for liquid drops whose scaled speed decreases with Ma and (2) asymptotic results for gas bubbles whose scaled speed is independent of Ma when it is large.