Flow-History-Dependent Behavior of Entangled Polymer Melt Flow Analyzed by Multiscale Simulation

Abstract

Polymer melts exhibit flow-history-dependent behavior. To clearly show this behavior, we have investigated the 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, polymer states around a cylinder on the downstream side differ from those around a cylinder on the upstream side because the former have a memory of the strain they experienced when passing around the cylinder on the upstream side but the latter have no such memory. Therefore, the shear stress distributions around two cylinders are found to differ. Moreover, we have found that the mean flow velocity decreases accordingly with increasing distance between the two cylinders, whereas the applied external force is constant. Although this behavior is consistent with that of the Newtonian fluid, the flow-historydependent behavior is found to enhance the reduction in the flow resistance. We have also discussed the microscopic states during the flow, observing the mean length of polymer chains, the mean number of entanglements, and the degree of orientation of polymer chains, which represented the flowhistory-dependent behavior that reflects each relaxation process.

Multiscale Simulation of Polymer Melt Spinning by Using the Dumbbell Model

“…By comparing the velocity and cross section area profiles with the end-point distribution for the dumbbell connective vectors, for dumbbells located in Lagrangian particles along typical places along the spinning line, we show that our multiscale simulation method successfully bridges the microscopic state of the system with its simultaneous macroscopic flow behavior. It is also confirmed that the present schemes gives good agreements two parallel plates 33,35,36,[41][42][43][44][45][46][47]50) , flows around an infinitely long cylinder 37,40,48,49) , flows in between eccentric rotating cylinders 38,39) and so forth. As far as we know, no one has ever 28,29) or NAPLES 26) , among many others.…”

“…So far, for flow problems of polymeric fluids a limited number of this type of multiscale simulations have been performed. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] Actually, the MSS method has…”

Synchronized Molecular-Dynamics Simulation via Macroscopic Heat and Momentum Transfer: An Application to Polymer Lubrication

“…However, the extension to the two-and three-dimensional cases is also possible by incorporating the algorithms developed in, for example, Refs. [16][17][18][19]. Second, almost perfect parallelization efficiency (i.e., using N CPUs in the parallel computation speeds up the calculation compared to using a single CPU by N times) is achieved in a parallel computation with as many CPUs as there are MD cells by assigning each CPU to an MD cell [21].…”

“…De et al proposed the scale-bridging method, which can correctly reproduce the memory effect of a polymeric liquid, and demonstrated the nonlinear viscoelastic behavior of a polymeric liquid in slab and cylindrical geometries [14,15]. The multiscale simulation for polymeric flows with the advection of memory in two and three dimensions was developed by Murashima and Taniguchi [16][17][18]. We have also developed a multiscale simulation of MD and computational fluid dynamics.…”

A Review on Transport Phenomena of Entangled Polymeric Liquids

“…6 (a) and (b). [142][143][144] Using this MSS method, both macroscopic ( Fig. 6 (c-i)) and microscopic ( Fig.…”