LATTICE BOLTZMANN SIMULATION OF INTERFACIAL DEFORMATION

Abstract

This study describes the numerical simulations of two-phase interfacial deformations using the binary fluid (BF) model in the lattice Boltzmann method (LBM), where a macroscopic fluid involves mesoscopic particles repeating collisions and propagations and an interface is reproduced in a self-organizing way by repulsive interaction between different kinds of particles. Schemes for the BF model are proposed to simulate motions of immiscible two phases with different mass densities. For higher Reynolds number, the finite difference-based lattice Boltzmann scheme is applied to the kinetic equations of particles, which include convection terms to reduce the diffusivity of each phase volume. In addition, two parameters are introduced into the BF model to adjust surface tension and interfacial thickness independently. The numerical results of three-dimensional bubble motion under gravity and two-dimensional droplet deformation under shear stress indicate that the lattice-Boltzmann BF model with the proposed schemes would be applicable to simulating interfacial dynamics of immiscible two-phase fluids.