Flow Analysis of Particle Suspensions in Polymeric Liquids using Mesoscopic Fluid Model

本署于2000至2002年在“科学研究资助计划（丙）”资助下进行“聚合物液体中悬浮微粒的流动分析”研究。本研究采用介观分子模型，如FENE（有限可扩展非线性弹性）哑铃来模拟聚合物分子，并利用布朗动力学模拟计算模型分子构型的演化。当周围没有粒子时，模型分子的运动仅由流动运动学和布朗运动决定。然而，颗粒对分子构型的演化有强烈的影响，在聚合物流体中颗粒悬浮液流动中，颗粒的运动也受到分子的影响。根据分子的构型、颗粒的取向和流动运动学计算悬浮液的应力，然后根据质量守恒定律和动量守恒定律预测悬浮液的流动运动学。在所提出的模拟策略中，由于直接估计分子和粒子的运动，模型分子和粒子之间的相互作用比连续体方法更容易理解。为了全面理解微结构流体的模具复杂流动，连续介质方法并不是一个合适的工具，有必要研究连续变化的流体微结构的演变过程。遗憾的是，我几乎不能得到分子与悬浮粒子相互作用机理的结果。因此，本文提出的方法应加以改进和扩展，以加工具有先进质量的颗粒增强材料。微复合材料是近年来在复合材料研究领域中兴起的一种新型复合材料。

A study on 'Flow analysis of particle suspensions in polymeric liquids' was carried out under the financial support of Research Project, Grant-in-Aid for Scientific Research (C) from 2000 to 2002.In this study polymer molecules were modeled by mesoscopic molecular model, e.g., FENE (Finitely Extensible Non-linear Elastic) dumbbell, and the evolution of the configuration of the model molecules was computed using the Brownian dynamics simulation. The movement of the model molecules is determined only by flow kinematics and Brownian motion when there is no particle around them. However, particles strongly affect the evolution of the molecule configuration, and also motion of particles is influenced by molecules in a flow of particle suspension in polymeric fluid. The stress of the suspension can be calculated from the configuration of molecules and orientation of particles as well as flow kinematics, then the flow kinematics of the suspensions is predicted on the basis of the mass and momentum conservation laws. In the proposed simulation strategy the interaction between model molecules and particles is rather understandable than the continuum approach owing to the direct estimation of the motion of both the molecules and particles.In order to fully understand die complex flow of fluid with micro-structure, the continuum approach is not an appropriate tool, and it is necessary to investigate the evolution of the micro-structure of the fluid which is continuously changed. Unfortunately I could not almost obtain the results on the mechanism of interaction between molecules and suspended particles. The proposed approach here, therefore, should be improved and extended for processing of particle-reinforced materials with advanced quality. This is the case for micro composites growing recently in the research field of the composite materials.