Brownian dynamics simulations of ferromagnetic colloidal dispersions in a simple shear flow

Abstract

We have carried out Brownian dynamics simulations to investigate the behavior of the clusters of ferromagnetic particles in a colloidal dispersion subjected to a simple shear flow. The results have been compared with those of Stokesian dynamics and Monte Carlo simulations. The main results obtained here are summarized as follows. The Brownian dynamics method can capture thick chainlike clusters formed along a magnetic field direction as well as the Stokesian dynamics and the Monte Carlo methods. However, Brownian motions of the particles give a subtle influence on the internal structure of the thick chainlike clusters even under the situation that magnetic particleparticle interactions dominate the particle Brownian motion. The Stokesian dynamics method misleads to physically unreasonable cluster formation for the case that the particle Brownian motions play an important role compared with the magnetic particle-particle interactions.