A numerical investigation of bubble dynamics in a ferrofluid by improved multicomponent multiphase pseudopotential lattice Boltzmann model coupled with magnetic field solver

Abstract

To simulate the dynamics of bubbles within a ferrofluid under the action of a uniform magnetic field, an improved multicomponent multiphase pseudopotential model with a multiple-relaxation-time collision operator coupled with the lattice Boltzmann model for solving magnetic field was constructed in the current study. By comparing with basic arithmetic examples and results of previous studies, it is well demonstrated that the coupled model proposed in this study has good reliability and accuracy in simulating the dynamics of bubbles in a ferrofluid under a uniform magnetic field. Then the proposed coupled model was used to study the dynamics characteristics of two asymmetrically arranged bubbles in a ferrofluid under the action of a horizontal uniform magnetic field. The results showed that the irregular nonlinear deformation, four representative bubble motion patterns, and the bubble oscillates along and perpendicular to the magnetic field direction were found in the dynamics of the bubbles. At different magnetic Bond numbers (Bom), the variation of distances parallel to the magnetic field (d) and distances perpendicular to the magnetic field (h) makes the nonlinear deformation effect, bubble motion mode, bubble oscillation amplitude, and bubble deformation throughout the process change accordingly. However, for each Bom number, different d and h at the same Bom number have almost no effect on the time of bubble oscillation and the deformation when the bubbles are stabilized after fusion.