Simulation of Droplet Displacement Using a Multicomponent Pseudopotential Lattice Boltzmann Model

In this paper, we present an improved multicomponent multiphase (MCMP) pseudopotential lattice Boltzmann (LB) model for large density ratio wetting. A modified pseudopotential-based fluid–solid interaction is adopted to improve the performance of the model. Then, wetting processes of the droplet on the horizontal wall are simulated to verify the validity of the improved model in the liquid–gas–solid system. It is found that the achievable contact angles can be ranged from 10° to 180° for static wetting processes using the proposed model. The density ratios obtained in this paper are all larger than 1200. Note that the maximum stray current in this paper is 0.016, which is smaller than the value found in the literature when the MCMP pseudopotential model is used. Next, the droplet displacement on a vertical wall is simulated. As the fluid–solid interaction strength increases, the terminal velocity increases. The effects of the obstacle height and the width on the droplet displacement are investigated. Increasing the obstacle height, the droplet gradually moves to the right until it collides with the right wall, and the time the droplet passes through the obstacle has no obvious change. As the obstacle width increases, the time the droplet passes through the obstacle increases. When the obstacle width increases to a certain value, the droplet cannot pass through the obstacle.