Multiphase curved boundary condition in lattice Boltzmann method

TL;DR

This paper introduces a new multiphase curved boundary condition for the lattice Boltzmann method that incorporates nonideal effects and error compensation, improving accuracy and mass conservation in complex geometries.

Contribution

It proposes a novel multiphase curved boundary condition that effectively handles complex geometries and wetting boundaries in lattice Boltzmann simulations.

Findings

Accurate and mass-conserving multiphase boundary treatment demonstrated.

Improved simulation accuracy with large density ratios.

Effective handling of complex geometries in multiphase flows.

Abstract

The boundary treatment is fundamental for modeling fluid flows; especially, in the lattice Boltzmann method, the curved boundary conditions effectively improve the accuracy of single-phase simulations with complex-geometry boundaries. However, the conventional curved boundary conditions usually cause dramatic mass leakage or increase when they are directly used for multiphase flow simulations. We find that the principal reason is the absence of nonideal effect in the curved boundary conditions, followed by the calculation error. In this paper, incorporating the nonideal effect into the linear interpolation scheme and compensating for the interpolating error, we propose a multiphase curved boundary condition to treat the wetting boundaries with complex geometries. A series of static and dynamic multiphase simulations with large density ratio verify that the present scheme is accurate and ensures mass conservation.