In microgravity environment, a droplet/bubble placed in an ambient fluid will move in the direction of
temperature gradient due to interface tension. This phenomenon called as thermocapillary migration is an
important topic in both fundamental hydrodynamics and practical applications. In this paper, advances in
theoretical analysis and numerical simulation of thermocapillary droplet migration in microgravity are
reported[1,2]. By using the frant tracking method, it is observed that the thermocapillary migration of a
planar non-deformed droplet with an uniform temperature gradients is steady at moderate Marangoni
numbers, but unsteady at large Marangoni numbers. The numerical results at large Marangoni numbers
qualitatively agree with of those of experimental investigations. From the overal steady-state energy balance
in the flow domain, a non-conservative integral thermal flux across the surface for a steady thermocapillary
droplet migration at large Marangoni numbers is found by using the asymptotic analysis. It presents that
the thermocapillary droplet migration at large Marangoni numbers cannot reach any steady states and is
thus a unsteady process. We thank the IMECH/SCCAS SHENTENG 1800/7000 research computing
facilities for assisting in the computation. This work was partially supported by the National Science
Foundation through the Grant No. 1172310.
修改评论