Droplet Motion with Evaporation and Condensation in One-Component Fluids
Recently, the dynamic van der Waals theory (DvdWT) has been presented for the study of hydrodynamics in one-component fluids with liquid-vapor transition in inhomogeneous temperature fields [Onuki A 2005 Phys. Rev. Lett. 94 054501]. We first derive the hydrodynamic boundary conditions at the fluid-solid interface for the DvdWT using conservation laws and the positive definiteness of entropy production together with the Onsager reciprocal relation. We then apply the DvdWT to the study of droplet motion driven by thermal gradients at solid surfaces. The effect of thermal singularity at the liquid-vapor-solid three phase contact line is investigated. The droplet motion predicted by the continuum hydrodynamic model is also observed and semi-quantitatively verified by performing molecular dynamics simulations for confined one-component two-phase fluids.