Challenges of numerical simulation of dynamic wetting phenomena: a review

Wetting is fundamental to many technological applications that involve the motion of the fluid-fluid interface on a solid. While static wetting is well-understood in the context of thermodynamic equilibrium, dynamic wetting is more complicated in that liquid interaction with a solid phase, possibly on molecular scales, can strongly influence the macroscopic scale dynamics. The problem with continuum models of wetting phenomena then is that they ought to be augmented with microscopic models to describe the molecular neighborhood of the moving contact line. In this review, widely used models for the computation of wetting flows are summarized first, followed by an overview of direct numerical simulations based on the volume-of-fluid approach. Recent developments in the volumeof-fluid simulations of the wetting are then reviewed, with particular attention paid to combine macro-scale simulations with the hydrodynamic theory near the moving contact line, as well as including a microscopic description by coupling with the van der Waals interface model. Finally, the extension to modeling the contact line motion on non-flat surfaces is surveyed, followed by hot topics in nucleate boiling.