Variation of Transport Properties Along Nanochannels: A Study by Non-equilibrium Molecular Dynamics

In the present work we calculate the transport properties of liquid argon for Poiseuille flow in a system confined by krypton walls using non-equilibrium molecular dynamics (NEMD) simulations where atoms interact via a Lennard-Jones potential. We examine the effect of channel width, system temperature and external force that drives the flow on diffusion coefficient, shear viscosity and thermal conductivity both as total average values for the whole channel, as well as local values across the channel. All transport properties are found to be significantly affected by the presence of the solid walls since their values in regions adjacent to the walls are different compared to those in layers near the channel centerline. In addition, for small channel widths where wall-fluid interaction affects most of the fluid region, transport properties present different behavior in comparison to bulk-like behavior. Following the nanoscale methodology described in the paper we can extract transport properties that can be used as input in macroscopic or multiscale simulations.