Multiscale method based on coupled lattice-Boltzmann and Langevin-dynamics for direct simulation of nanoscale particle/polymer suspensions in complex flows

TL;DR

This paper introduces a hybrid multiscale computational method combining lattice-Boltzmann and Langevin-dynamics to efficiently simulate nanoscale particle and polymer suspensions in complex flows, capturing thermal fluctuations and hydrodynamic interactions.

Contribution

A novel coupled LB-LD method with an Eulerian-host algorithm for scalable, accurate simulation of nanoscale suspensions in complex flow environments.

Findings

Good agreement with theoretical predictions

Validated against experimental data

Efficient scalability for large particle systems

Abstract

A hybrid computational method coupling the lattice-Boltzmann (LB) method and a Langevin-dynamics (LD) method is developed to simulate nanoscale particle and polymer (NPP) suspensions in the presence of both thermal fluctuation and long-range many-body hydrodynamic interactions (HI). Brownian motion of the NPP is explicitly captured by a stochastic forcing term in the LD method. The LD method is two-way coupled to the non-fluctuating LB fluid through a discrete LB forcing source distribution to capture the long-range HI. To ensure intrinsically linear scalability with respect to the number of particles, an Eulerian-host algorithm for short-distance particle neighbor search and interaction is developed and embedded to LB-LD framework. The validity and accuracy of the LB-LD approach are demonstrated through several sample problems. The simulation results show good agreements with theory and experiment. The LB-LD approach can be favorably incorporated into complex multiscale computational frameworks for efficiently simulating multiscale, multicomponent particulate suspension systems such as complex blood suspensions.