Abstract/Summary

As more and more promising applications of magnetic nanoparticles in complicated environments are explored, their flow properties in porous media are of increasing interest. We here propose a hybrid approach based on the Multiparticle Collision Dynamics Method extended to porous media via friction forces and coupled with Brownian Dynamics simulations of the rotational motion of magnetic nanoparticles’ mag- netic moment. We simulate flow in planar channels homogeneously filled with a porous medium and verify our implementation by repro- ducing the analytical velocity profile of the Darcy-Brinkman model in the non-magnetic case. In the presence of an externally applied mag- netic field, the non-equilibrium magnetization and friction forces lead to field-dependent velocity profiles that result in effective, field-dependent permeabilities. We provide a theoretical expression for this magneto- permeability effect in analogy with the magneto-viscous effect. Finally, we study the flow through planar channels, where only the walls are covered with a porous medium. We find a smooth crossover from the Poiseuille profile in the center of the channel to the Brinkman-Darcy flow in the porous layers. We propose a simple estimate of the thickness of the porous layer based on the flow rate and maximum flow velocity.