Electromagnetic flow around two non-conducting particles and the interaction forces-different diameter cases

In this study, electromagnetic (em) migration forces exerted to two non-conducting particles having different diameters are investigated, which are in conducting liquid with imposition of DC em field. The electro-magnetically-driven flow (em-flow) around the particles was analyzed numerically. Its influence on the interaction force between the particles and on the magnitude of em migration forces (Gc) were examined for the two particles in three configurations; Direction of two particles in a row is either parallel to the current (Case 1), or to the magnetic field (Case 2), or to the em force (Case 3). Four circulating flows were formed around the two particles. Strong penetrating flow between the particles existed in Case 1 and 2, but they had different flow directions. In Case 3, the penetration flow was weak. The migration force exerted to the small particle was influenced markedly. In Case 1, Gc of small particle is larger than that of the large particle twice as much. In Case 2, the direction of em migration force was opposite to the large particle. These relative differences in em migration force correspond to the repulsive interaction between the particles. Interaction forces along directions of the particles in the row were negligibly small in all three cases. Nature of generating interaction forces between the particles was discussed by considering the pressure distribution on the particle surface.