Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation

TL;DR

This study uses multiscale simulation to explore how entangled polymer melts exhibit flow-history-dependent behavior, revealing that flow around cylinders depends on prior strain history, affecting shear stress and flow velocity.

Contribution

It demonstrates the flow-history-dependent behavior of entangled polymer melts around cylinders using multiscale simulation, highlighting the impact of strain history on flow resistance.

Findings

Shear stress distributions differ around upstream and downstream cylinders.

Flow velocity decreases with increasing distance between cylinders.

Flow-history-dependent behavior enhances flow resistance reduction.

Abstract

Polymer melts represent the flow-history-dependent behavior. To clearly show this behavior, we have investigated flow behavior of an entangled polymer melt around two cylinders placed in tandem along the flow direction in a two dimensional periodic system. In this system, the polymer states around a cylinder in downstream side are different from the ones around another cylinder in upstream side because the former ones have a memory of a strain experienced when passing around the cylinder in upstream side but the latter ones do not have the memory. Therefore, the shear stress distributions around two cylinders are found to be different from each other. Moreover, we have found that the averaged flow velocity decreases accordingly with increasing the distance between two cylinders while the applied external force is constant. While this behavior is consistent with that of the Newtonian fluid, the flow-history-dependent behavior enhances the reduction of the flow resistance.