Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Mechanical Engineering
Rheological Study Of Polymer Flow Past Rough Surfaces With Slip Boundary Conditions, Anoosheh Niavarani, Nikolai V. Priezjev
Rheological Study Of Polymer Flow Past Rough Surfaces With Slip Boundary Conditions, Anoosheh Niavarani, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
The slip phenomena in thin polymer films confined by either flat or periodically corrugated surfaces are investigated by molecular dynamics and continuum simulations. For atomically flat surfaces and weak wall-fluid interactions, the shear rate dependence of the slip length has a distinct local minimum which is followed by a rapid increase at higher shear rates. For corrugated surfaces with wavelength larger than the radius of gyration of polymer chains, the effective slip length decays monotonically with increasing corrugation amplitude. At small amplitudes, this decay is reproduced accurately by the numerical solution of the Stokes equation with constant and rate-dependent local …
Slip Boundary Conditions For Shear Flow Of Polymer Melts Past Atomically Flat Surfaces, Anoosheh Niavarani, Nikolai V. Priezjev
Slip Boundary Conditions For Shear Flow Of Polymer Melts Past Atomically Flat Surfaces, Anoosheh Niavarani, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
Molecular dynamics simulations are carried out to investigate the dynamic behavior of the slip length in thin polymer films confined between atomically smooth thermal surfaces. For weak wall-fluid interactions, the shear rate dependence of the slip length acquires a distinct local minimum followed by a rapid growth at higher shear rates. With increasing fluid density, the position of the local minimum is shifted to lower shear rates. We found that the ratio of the shear viscosity to the slip length, which defines the friction coefficient at the liquid/solid interface, undergoes a transition from a nearly constant value to the power …