Nano-scale water Poiseuille flow: MD computational experiment

Abstract

Because viscosity plays an important role in physical fluid flow applications, this property must be described accurately in com- puter simulations. As a most popular Newtonian fluid on earth, water has a special role in scientific and technical applications. The simulation of water with molecular dynamics (MD) includes granular matter of long-range interacting H2O molecules, and simula- tions using discrete element method, as well as experimental studies of the dynamics of spheres with sub-millimetre radii, of such systems demonstrate non-Newtonian behaviour. Therefore, the flow of water molecules with complex shapes and long-range non- linear interactions in nano-scaled fluid devices—in contrast to macro-scaled devices—is also likely to demonstrate non-Newtonian behaviour. In this study, we used molecular dynamics simulations, with a temperature range of 273 K to 363 K, to study the SPC/E water Poiseuille flow inside a nanochannel consisting of two parallel silicon plates. The results indicate non-Newtonian behaviour of molecular water flow at nanoscales.