Simulation of Drops on Surfaces

This chapter explores various methods for simulating drop dynamics on solid surfaces, and highlights that the key challenge in predictive modeling of such systems is in capturing the complex behavior of moving contact lines and the associated contact angles. The usual approach to simulating fluid flows is to consider the fluids involved as continuous media, that is, without an underlying molecular composition. The chapter explores some of the features and phenomena related to contact angles that make predictive simulation of drops on surfaces so challenging. In contrast with the sharp-interface models, diffuse-interface models begin with the perspective that liquid interfaces have a finite thickness over which thermodynamic variables change smoothly but rapidly between the bulk values on either side. The lattice Boltzmann (LB) method is a mesoscopic method, which has been applied to a very diverse range of problems including many studies of drop dynamics and wetting.