Molecular Simulation of Reentrant Corner Flow

Abstract

Molecular dynamics simulations are used to compute the flow of both a simple atomistic liquid and a model polymer melt through a channel with a reentrant corner. In the Newtonian case, the shear stress near the corner is found to agree with the Stokes flow prediction of Moffatt [J. Fluid Mech. 18, 1 (1964)]. In the non-Newtonian case, the shear stress has a stronger apparent power-law divergence but the exponent appears to saturate at an integrable value of approximately 0.8 for all chain lengths. The molecular origin of the stress enhancement is that the extensional flow near the reentrant corner flow tends to elongate the molecules.