A diffuse-interface lattice Boltzmann method for fluid-particle interaction problems

TL;DR

This paper introduces a diffuse-interface lattice Boltzmann method (DI-LBM) for fluid-particle interactions, replacing sharp interfaces with a smooth transition region to improve accuracy and efficiency in simulations.

Contribution

The paper develops a novel DI-LBM that models fluid-particle interfaces with a diffuse region and incorporates a modified force term for better accuracy.

Findings

DI-LBM shows good agreement with theoretical and numerical results.

DI-LBM is more efficient and accurate than the PS-LBM with superposition model.

The method effectively captures fluid-particle interactions in classical problems.

Abstract

In this paper, a diffuse-interface lattice Boltzmann method (DI-LBM) is developed for fluid-particle interaction problems. In this method, the sharp interface between the fluid and solid is replaced by a thin but nonzero thickness transition region named diffuse interface, where the physical variables varies continuously. In order to describe the diffuse interface, we introduce a smooth function, which is similar to the order parameter in phase-field model or the volume fraction of solid phase in the partially saturated lattice Boltzmann method (PS-LBM). In addition, to depict the fluid-particle interaction more accurately, a modified force term is also proposed and included in the evolution equation of the DI-LBM. Some classical problems are used to test the DI-LBM, and the results are in good agreement with some available theoretical and numerical works. Finally, it is also found that the DI-LBM is more efficient and accurate than the PS-LBM with the superposition model.