Molecular dynamic simulation of nano-sized channel flow

Liquid flow passes through two parallel plates are simulated using molecular dynamic method. The flowing systems consist of 2744, 5488, and 8232 Argon molecules inside channels with heights of 40Å, 80Å, and 120Å respectively and the liquid Argon is sandwiched between two solid walls. The wall is comprised of fcc 〈111〉 surface of 510 platinum molecules. The potentials between argon-argon and argon-platinum are well-known Lennard-Jones functions. The flow behavior is studied by two driven mechanisms: (1) pulling two parallel plates at a constant velocity with zero pressure gradients, and (2) pressure gradient. The phantom molecules are used to mimic the constant temperature boundary. Velocity profiles with slip boundaries and laminar friction constants are calculated to support the validation of continuous theory with appropriate modifications. This study finds that the channel size, driving mechanism and its magnitude are the factors determining slip/non-slip velocity and the laminar friction constant.