Simplified Magnetic Induction Field of Magnetite Particles With Irregular Shape

Magnetic induction field (MIF) of the magnetite particles with five Johnson solid shapes was analyzed using the finite-element method. A new method is proposed to calculate the MIF of irregular magnetite particles by studying their magnetic flux density, and the results show that sphericity is a key factor affecting the MIF of a regular-shaped particle. Moreover, the calculation value of the MIF using particle volume radius ( $r$ ) is more accurate with the higher sphericity. In addition, the relative position is another important factor affecting the accuracy of MIF calculation. The further the distance from the particle center, the more accurate is the MIF. More specifically, when the distance is $4r$ , the average value of the relative difference drops to less than 5.0% with the sphericity of 0.91, 0.92, and 0.93, respectively. Therefore, we suggest that it is feasible to use a sphere MIF instead of an irregular particle MIF to simulate the interaction and motion of massive magnetite particles.