Lattice Boltzmann simulations of magnetic particles in a three-dimensional microchannel

Abstract A lattice Boltzmann model for magnetic particles in a fluid is established, in which both hydrodynamic and magnetic interactions are fully coupled. The interpolated bounce back scheme is adopted to describe the fluid-particle interaction. We combine the implicit particle velocity updated scheme and the modified momentum-exchange method to make the algorithm stable and also maintain the Galilean invariance. Moreover, MPI + OpenMP hybrid programming mode is used for parallel computing. The model is validated by numerical simulation of the sedimentation of a particle in a tank. We investigate the motion of magnetic particles in a microchannel with carrier fluid under the uniform magnetic field and hybrid magnetic field, and then the magnetic particles flow through a variable-section microchannel is studied. The results indicate that the structures formed by magnetic particles can be regulated by controlling the external magnetic field and flow field; besides, the more ordered structures have more influence on the fluid flow.