https://hal-polytechnique.archives-ouvertes.fr/hal-01024937Sellier, AntoineAntoineSellierLadHyX - Laboratoire d'hydrodynamique - X - Ă‰cole polytechnique - CNRS - Centre National de la Recherche ScientifiqueMigration of an insulating particle under the action of uniform ambient electric and magnetic fields. Part 2. Boundary formulation and ellipsoidal particlesHAL CCSD2003[PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph][SPI.MECA.MEFL] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]Roura, Denis2014-08-27 12:50:062020-07-27 13:00:052014-09-08 10:38:31enJournal articleshttps://hal-polytechnique.archives-ouvertes.fr/hal-01024937/document10.1017/s0022112003004944application/pdf1This paper examines the low-Reynolds-number migration of an insulating and rigid particle that is freely suspended in a viscous liquid metal and subject to uniform ambient electric and magnetic fields E and B. Under the same physical assumptions as Part 1, a whole boundary formulation of the problem is established. It allows the determination of the particle rigid-body motion without calculating the modified electric field and the flow induced by the Lorentz body force in the fluid domain. The advocated boundary approach, well-adapted for future numerical implementation, makes it possible to obtain an analytical expression for the translational velocity of any ellipsoidal particle (the simplest case of non-spherical orthotropic particles). The behaviour of a spheroid is carefully investigated and discussed both without and with gravity. The migration of this simple non-spherical particle is found to depend on both its nature (prolate or oblate) and the ambient uniform fields E and B. The spheroid translates without rotation, and not necessarily parallel to E ? B. For adequately selected fields E and B, the spheroid may either migrate parallel or anti-parallel to a sphere and even be motionless.