Phase asymmetry in thermocapillary motion

Abstract

It is shown that bulk thermodynamic effects, in addition to surface tension effects, can play a crucial role in thermocapillary phenomena ͑e.g., bubble or droplet thermomigration and phase separation in multi-phase systems subjected to an imposed temperature gradient͒ due to asymmetric thermodynamic properties of the underlying coexisting phases. The resultant new phenomena are elucidated in a representative model of diffusive systems with a conserved order parameter.

Nonequilibrium interface equations: An application to thermocapillary motion in binary systems

“…5a of Ref. [6]) Good agreement with the R −1 dependence as predicted in Eq. ( 18) is found supporting the validity of the interface equation approach based on local equilibrium.…”

“…In fact the mesoscopic shift in chemical potential alone drives the slab to the hotter side. This phenomenon will be addressed elsewhere [19].…”

“…Using this approach, we investigate as an example, thermo-capillary driven motion of a droplet in both binary diffusive and binary fluid systems in an imposed temperature gradient. Note that motion of a droplet in the hydrodynamic case has been well explored by the use of macroscopic techniques [3][4][5], while diffusion driven thermo-capillary motion has not been received much attention in the literature [6]. Thus, to the best of our knowledge, our modeling approach provides a first detailed comparison for the droplet motion in these two distinctly different cases.…”

“…Thermocapillary phenomena associated with such type of thermal gradients have been numerically investigated recently in Refs. [8,16,17,6]. Note that the spatial variation and hence, the temperature field, is fixed, corresponding to large thermal conductivity of the medium.…”

Phase field simulation of monotectic transformation for liquid Ni-Cu-Pb alloys

“…Previously, Tanaka [4] explored the interplay between wetting and phase separation for organic mixtures using the phase field model, and found that hydrodynamics plays an important role in bicontinuous phase separation. Afterwards, Bhagavatula and Jasnow [5] investigated the influence of Marangoni migration on phase separation. In principle, Marangoni migration originates from the melt temperature gradient, which drives the second liquid phase towards the higher temperature region.…”