Molecular Simulation of Viscous Flow

Sometimes the continuum equations of fluid mechanics must be completed by information about processes occurring at microscopic seals. For example, we can consider the formulation of boundary conditions, the resolution of singular solutions of the governing equations, and the determination of constitutive relations. In such situations, molecular dynamics calculations can be simulated at the atomic scale and provide the missing information. We review the numerical procedure and then discuss several recent applications of this technique. We consider the validity of lubrication theory at very short distances, the smoothing of corner singularities for both Newtonian and non-Newtonian fluids, and some molecular aspects of wetting phenomena, particularly contact angle hysteresis.