Numerical simulation of effectively driving the trajectory of magnetic particles in a Newtonian fluid using a uniform magnetic field

Herein, the interaction and relative motion of two circular magnetic particles in a static flow and planar Poiseuille flow is investigated via numerical simulation. A two-dimensional numerical model is constructed based on Maxwell's finite element method, fully considering the interactions between particles and particles, particles and magnetic fields, and particles and flow fields. First, the motion state and action mechanism of the magnetic particles in contact state in the static fluid are analyzed under a vertical magnetic field; then, the simulation results are verified via experiments. Based on the motion state of the magnetic particles in the planar Poiseuille flow, the feasibility of effectively controlling the trajectory of magnetic particles in the planar Poiseuille flow using a magnetic field is discussed. In the static flow, the vertical magnetic field was unable to separate the contacting magnetic particles; thus, the magnetic field cannot effectively control magnetic particles in static flows. In the planar Poiseuille flow, the free contact and separation of magnetic particles was effectively controlled by the combined action of the magnetic field and the fluid. This study provides insights into the interactions among magnetic particles in static flows and summarizes a set of methods for effectively controlling two circular magnetic particles.