LBM-IBM-DEM modelling of magnetic particles in a fluid

A lattice Boltzmann method-immersed boundary method-discrete element method (LBM-IBM-DEM) scheme was presented to simulate the behavior of magnetic particles in a fluid with external magnetic field. In the present scheme, the flow field was solved by the LBM, the DEM with the consideration of the magnetic force was used to describe the particle behavior and the flow field was computed by the momentum exchange-based IBM. Numerical simulations of fluid-particle interactions with uniform magnetic fields in different directions (vertical magnetic field and transverse magnetic field) were carried out to study the particle motion and hydrodynamic behavior in details. The numerical results indicated that the external magnetic force has a significant influence on the particle behavior, where some fragmented chains along the direction are formed and these chain-like clusters continue to lengthen, align, and approach an almost steady state. In addition, we also studied the effect of the magnetic field strength on the motion of magnetic particles showing that in the same particle system, stronger magnetic field brings magnetic particles greater kinetic energy than the low density magnetic field does.