Anisotropic Lennard-Jones fluids in a nanochannel

During the past few decades molecular dynamics has been a widely applied tool to simulate fluid confined in micro/nano geometries. What makes interfacial fluids fundamentally different from the bulk fluid is the fact that their density varies considerably over microscopic distances. A class of such strongly inhomogeneous fluids are fluids confined in very narrow channels by solid boundaries. In this work, the goal is to study the density and stress terms across the channel. We simulate planar Poiseuille flow of a Lennard-Jones fluid in channels of various widths in the nanoscale regime. A body force and a local thermostat are applied in order to simulate a steady-state flow. Layering and anisotropy in stress are obtained near the walls of the channel, which leads to non-Newtonian rheology. Understanding and quantifying the non-Newtonian behavior is a first step towards deriving a constitutive model that describes locally the behavior of a strongly confined fluid.