Calculation of thermo-physical properties of Poiseuille flow in a nano-channel

In this article, flow of Lennard-Jones fluid through a nano-channel is studied with molecular dynamics (MD). The present study examines the thermo-physical properties of a gaseous flow between parallel walls at various rarefaction levels. The walls of the channel are maintained at a constant temperature while the rarefaction levels of the fluid are in the transition regime. The properties of gravity driven Poieuille flow, such as the density profiles across the channel, collision frequency on the walls and velocity profiles are investigated using MD. The amount of slip and tangential momentum accommodation coefficient (TMAC) are investigated, and the amount of slip is predicted using calculated values of TMAC. Using MD data, viscosity of the Poiseuille flow is investigated using the model based on kinetic theory. Subsequently, from the calculated values of TMAC, the dimensionless friction constant is calculated for different flow conditions. The value of the friction constant predicted using the Maxwell slip model is compared with the value obtained using a second order slip model. The second order model, which employ calculated values of TMAC, gives promising results on friction constant at moderately rarefied conditions. (C) 2012 Elsevier Ltd. All rights reserved.