Axisymmetric thermal wake interaction of two drops in a gravity field at low Reynolds and high Peclet numbers

The axisymmetric motion of two drops in a viscous fluid under combined effect of gravity and thermocapillarity is considered. The ambient fluid is isothermal far from the drops and the temperature of the leading drop exceeds that of the continuous media. At large Peclet number, thermal boundary layers are present along the interfaces, and thermal wakes are formed downstream of the drops. The interaction of the thermal wake, shedded from the leading drop, with the boundary layer of the trailing one was shown to influence significantly the temperature distribution on the surface of the latter. The induced change in the speed of the trailing drop is comparable in magnitude with its speed when isolated even for large separation distance between the drops where the hydrodynamic interaction is negligible. In the extreme case of very large Marangoni effect the direction of the trailing drop motion can be reversed.