Thermocapillary migration of bubbles: Convective effects at low Péclet number (Q2755607)

The authors examine the effect of weak convective heat transfer on the thermocapillary interaction of two bubbles migrating in an externally imposed temperature gradient. It is shown that equal-sized bubbles, which otherwise would move with equal velocities, acquire a relative motion apart from each other under the influence of convection. For slightly unequal bubbles, there are three different regimes of large-time asymptotic behaviour. Sufficient conditions for the realization of each regime are given in terms of Péclet number, initial separation and radii ratio.