Multiscale Simulation of History Dependent Flow in Polymer Melt

TL;DR

This paper introduces a multiscale simulation method to study how the flow of entangled polymer melts depends on their deformation history, revealing nonlinear behaviors influenced by stress memory.

Contribution

A novel multiscale simulation approach combining smoothed particle hydrodynamics with microscopic models for entangled polymers.

Findings

Stress memory causes nonlinear flow behavior even at low Weissenberg numbers.

Entanglement distribution is affected by obstacles, with broader entanglement depletion downstream.

Flow behavior is significantly influenced by the history-dependent stress in the polymer melt.

Abstract

We have developed a new multiscale simulation technique to investigate history-dependent flow behavior of entangled polymer melt, using a smoothed particle hydrodynamics simulation with microscopic simulators that account for the dynamics of entangled polymers acting on each fluid element. The multiscale simulation technique is applied to entangled polymer melt flow around a circular obstacle in a two-dimensional periodic system. It is found that the strain-rate history-dependent stress of the entangled polymer melt affects its flow behavior, and the memory in the stress causes nonlinear behavior even in the regions where ${\rm Wi} \le 1$. The spatial distribution of the entanglements $<Z>$ is also investigated. The slightly low entanglement region is observed around the obstacle and is found to be broaden in the downstream region.