Numerical simulations on thermocapillary migrations of nondeformable droplets with large Marangoni numbers

In this paper, the study on isolated spherical drops in thermocapillary migrations in zero gravity is carried out with a novel numerical scheme to accomplish long-tank simulations in a very short computing domain, and the full migrating phenomena with fairly large Marangoni numbers (up to 400) are discussed in detail. Larger Marangoni numbers lead to more complicated migrating processes, and longer distances for the drops to reach their final stable migrating velocities (U-F). There is nontrivial difference between the U-F values in theoretical analysis, numerical simulations, and space experiments, and the most possible reason is the assumed different migrating distances to reach steady states in different investigations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752028]