Lattice Boltzmann simulation of three-phase flows with moving contact lines on curved surfaces

Abstract

A numerical method for simulating three-phase flows with moving contact lines on arbitrarily complex surfaces is developed in the framework of lattice Boltzmann method. In this method, the immiscible three-phase flow is modeled through a multiple-relaxation-time color-gradient model, which not only allows for a full range of interfacial tensions but also produces stable outcomes for a wide range of viscosity ratios. A characteristic line model is introduced to implement the wetting boundary condition, which is not only easy to implement but also able to handle arbitrarily complex boundaries with prescribed contact angles. The developed method is first validated by the simulation of a Janus droplet resting on a flat surface, a perfect Janus droplet deposited on a cylinder, and the capillary intrusion of ternary fluids for various viscosity ratios. It is then used to study a compound droplet subject to a uniform incoming flow passing through a multi-pillar structure, where three different values of

Prediction of three-phase relative permeabilities of Berea sandstone using lattice Boltzmann method

“…In this work, a lattice Boltzmann color-gradient model recently improved by our group (Li et al, 2021;Yu et al, 2019b)…”

“…In our previous work (Li et al, 2021), the present model has been validated by a series of static and dynamic tests, and it was demonstrated to be capable of accurately Poiseuille-type flow in the channel, the analytical solution for the velocity profile ( ) u y can be obtained (Jiang et al, 2020)…”

“…The wetting boundary condition is implemented using the characteristic line method recently proposed by Li et al (Li et al, 2021), in which the desired contact angles are realized by specifying the values of mass fraction at the solid nodes adjacent to the boundary (a list of these nodes is denoted as B S  ) using two possible characteristic lines. The implementation of the boundary condition will be briefly described below, and one can refer to Li et al (Li et al, 2021) for more details. , .…”

“…To fill the gap mentioned above, we will use the lattice Boltzmann color-gradient model recently improved by our group (Li et al, 2021;Yu et al, 2019b) to simulate the immiscible three-phase flows in a two-dimensional (2D) pore network of realistic Berea sandstone. In particular, we will focus on a ternary fluid system where the largest interfacial tension equals the sum of the other two.…”

Influence of the pre-impact shape of an oil droplet on the post-impact flow dynamics at air–water interface

“…13,14 Recently, a few theoretical studies have developed the mathematical approach to tackle the flow situations which deal with the presence of ternary phases in the system. [39][40][41][42][43][44] These mathematical models generally form a diffused interface model based on minimization of the free energy to study the dynamics of a triplet of coupled deformable interfaces. 39,40 Prior art also suggests that, a few numerical models explored the metastable flow morphologies arising from the spherical oil drop impact with an air-water interface where the impact velocity is relatively low.…”