Multiphase curved boundary condition in lattice Boltzmann method

Abstract

The boundary treatment is fundamental for modeling fluid flows; especially, the curved boundary condition, which accurately describes the boundary geometry, can effectively improve the accuracy of simulations with complex boundaries. However, although curved boundary conditions have been successfully applied in single-phase lattice Boltzmann simulations, they cause dramatical mass leakage or increase when it is directly used for multiphase flows. We find that the principal reason is the absence of nonideal effect, followed by the calculation error. In this paper, incorporating the nonideal effect into the linear interpolation scheme and compensating the interpolating error, we propose a multiphase curved boundary condition to treat 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.