A volume of fluid method for simulating fluid/fluid interfaces in contact with solid boundaries

Kyle Mahady, Shahriar Afkhami, Lou Kondic

Published 2014-09-03Version 1

In this paper, we present a novel approach to model the fluid/solid interaction forces of a general van der Waals type in a direct solver of the Navier-Stokes equations based on the volume of fluid interface tracking method. The key ingredient of the model is the explicit inclusion of the fluid/solid interaction forces into the governing equations. We show that the interaction forces lead to a partial wetting condition and in particular to a natural definition of an equilibrium contact angle. We present two numerical approaches for the discretization of the interaction forces that enter the model. These two approaches are found to be complementary in terms of convergence properties and complexity. To validate the computational framework, we consider the application of these models to simulate two-dimensional drops at equilibrium, as well as drop spreading. We find that the proposed methods can accurately describe the physics of the considered problems. In general, the model allows for the accurate treatment of a variety of problems involving wetting and dewetting for arbitrary contact angles.