Lattice Boltzmann simulations of anisotropic particles at liquid interfaces

TL;DR

This paper demonstrates the use of lattice Boltzmann simulations combined with molecular dynamics to study the behavior of anisotropic particles at liquid interfaces, including complex shape effects and emulsion stabilization.

Contribution

It extends existing models to anisotropic ellipsoidal particles and discusses practical experiences with large-scale supercomputing simulations.

Findings

Successful simulation of particle adsorption at fluid interfaces

Insights into emulsion stabilization by anisotropic particles

Model applicability to complex-shaped colloids

Abstract

Complex colloidal fluids, such as emulsions stabilized by complex shaped particles, play an important role in many industrial applications. However, understanding their physics requires a study at sufficiently large length scales while still resolving the microscopic structure of a large number of particles and of the local hydrodynamics. Due to its high degree of locality, the lattice Boltzmann method, when combined with a molecular dynamics solver and parallelized on modern supercomputers, provides a tool that allows such studies. Still, running simulations on hundreds of thousands of cores is not trivial. We report on our practical experiences when employing large fractions of an IBM Blue Gene/P system for our simulations. Then, we extend our model for spherical particles in multicomponent flows to anisotropic ellipsoidal objects rendering the shape of e.g. clay particles. The model is applied to a number of test cases including the adsorption of single particles at fluid interfaces and the formation and stabilization of Pickering emulsions or bijels.