标题： 使用耦合格子玻尔兹曼和朗之万动力学方法模拟纳米尺度的粒子和聚合物悬浮液 显示英文标题

标题： Simulating nanoscale suspension of particles and polymers using a coupled lattice-Boltzmann and Langevin-dynamics approach

摘要： 一种新颖的计算方法，将格子玻尔兹曼（LB）方法与朗之万动力学（LD）方法相结合，已被开发用于模拟存在热涨落和多体流体动力学相互作用（HI）的纳米尺度悬浮液，并具有线性可扩展性。 纳米尺度颗粒/聚合物（NPP）的动力学通过LD进行解析，NPP的布朗运动由随机力项直接驱动。 通过引入离散的LB力源项，LB方法与LD以双向方式耦合，以直接包含并解析稀释区域内的多体HI。 通过几个验证问题证明了LB-LD方法的有效性和准确性，包括单个颗粒的速度弛豫、纳米颗粒（NP）群的自扩散以及单个聚合物链的弛豫。 观察到模拟与理论之间有良好的一致性。 为了确保粒子动力学的完全定位和线性可扩展性，引入了一个欧拉主机算法，用于高效地进行短程成对粒子搜索和相互作用。 由于纳米尺度悬浮液动力学旨在通过亚晶格技术完全解析，因此这种LB-LD方法可以有利地整合到复杂的多尺度计算框架中，用于生物和工业多模态悬浮应用。 显示英文摘要

摘要： A novel computational approach coupling the lattice-Boltzmann (LB) method and a Langevin-dynamics (LD) approach has been developed to simulate nanoscale suspensions in the presence of both thermal fluctuation and many-body hydrodynamic interactions (HI) with linear scalability. The dynamics of the suspended nanoscale particle/polymer (NPP) are resolved through the LD with the NPP Brownian motion explicitly driven by the stochastic force term. By introducing a discrete LB forcing source term, the LB method is coupled with the LD in a two-way fashion to directly include and resolve the many-body HI in the dilute regime. The validity and accuracy of this LB-LD approach are demonstrated through several verification problems, including velocity relaxation of an isolated particle, self-diffusion of a nanoparticle (NP) swarm, and relaxation of a single polymer chain. Good agreement between simulation and theory is observed. To ensure complete localization and linear scalability of the particle dynamics, an Eulerian host algorithm for efficient short-range pairwise particle search and interaction is introduced. Since the nanoscale suspension dynamics are intended to be fully resolved via sub-lattice techniques, this LB-LD approach can be favorably incorporated into complex multiscale computational frameworks for both biological and industrial multimodal suspension applications.