Comparison of different models of magnetic nanoparticle aggregation in microchannels with magnetic field

Abstract

The phenomenon of nanoparticle aggregation is relevant for the applications in which magnetic nanoparticles are used and controlled by a magnetic field. In this work, the validity of an improved model for the magnetic nanoparticle aggregation in microchannels in an external magnetic field is investigated. The nanoparticles in the magnetic field are arranging into chains whose orientation is parallel to the external magnetic field in the absence of other forces. These chains were described in our previous work with a linear chain model, which was later used to establish a specialized macroscopic two-phase CFD model and solver. This solver is capable of modelling the MNP aggregation on the macroscopic scale without enormous computational demands. In this paper, the proposed linear chain model is compared to more detailed discrete particle model simulations, which were performed with an extended version of OpenFOAM’s discrete particle solver DPMFoam. In the simulations, several configurations were investigated, including single particle chains with different lengths or chain distributions at the different particle concentrations.