论文标题
具有波动的内部摩擦和流体动力相互作用的有限延伸链的剪切粘度
Shear viscosity for finitely extensible chains with fluctuating internal friction and hydrodynamic interactions
论文作者
论文摘要
到目前为止，尚未提出具有波动内部摩擦和流体动力相互作用的粗粒聚合物模型的精确解决方案，这是由于连接器矢量速度之间的一对一耦合，从而排除了管理随机微分方程的表述。提出了一种用于去除此耦合的方法，并且使用Brownian Dynamics模拟进行了数值集成，从而通过将动力学解释连接到系统的Fokker-Planck方程来获得的管理随机微分方程。提出的计算途径消除了在具有内部摩擦的模型中出现的扩散张量的差异的计算，并且比基于递归的算法的速度快于一个先前开发的基于递归的算法[J. Rheol。，65，903（2021）]用于用内部摩擦的自由排水模型的解决方案。研究了有限的扩展性，内部摩擦和流体动力相互作用对稳定剪切粘度的各种组合的相互作用的影响。虽然有限的可扩展性仅导致剪切，但内部摩擦和流体动力相互作用都会导致剪切粉化，然后进行剪切厚。由于流体动力的相互作用，由内部摩擦效应引起的剪切塑性更为明显。
An exact solution of coarse-grained polymer models with fluctuating internal friction and hydrodynamic interactions has not been proposed so far due to a one-to-all coupling between the connector vector velocities that precludes the formulation of the governing stochastic differential equations. A methodology for the removal of this coupling is presented, and the governing stochastic differential equations, obtained by attaching a kinetic interpretation to the Fokker-Planck equation for the system, are integrated numerically using Brownian dynamics simulations. The proposed computational route eliminates the calculation of the divergence of the diffusion tensor which appears in models with internal friction, and is about an order of magnitude faster than the recursion-based algorithm for the decoupling of connector-vector velocities previously developed [J. Rheol., 65, 903 (2021)] for the solution of freely draining models with internal friction. The effects of the interplay of various combinations of finite extensibility, internal friction and hydrodynamic interactions on the steady-shear-viscosity is examined. While finite extensibility leads solely to shear-thinning, both internal friction and hydrodynamic interactions result in shear-thinning followed by shear-thickening. The shear-thickening induced by internal friction effects are more pronounced than that due to hydrodynamic interactions.
