Application of the Lattice Boltzmann Method to Many Particle Dispersions

Abstract

We have discussed the feasibility of the lattice Boltzmann method as a simulation technique with multi-body hydrodynamic interactions for many particle dispersions. To do so, we consider aggregation phenomena in a two-dimensional suspension composed of magnetic particles. The validity of the present results has been discussed by comparing with those of Monte Carlo and Brownian dynamics simulations. The results obtained here are summarized as follows. The density ratio between magnetic particles and the ambient liquid does not significantly influence the cluster formation. If relatively coarse lattices are used, physically reasonable aggregate structures can be obtained, but fine lattice systems cause invalid aggregate formation of particles, which means that the particle Brownian motion cannot be activated properly in the latter case. The results concerning the pair correlation function and magnetization curves clearly show that the lattice Boltzmann results are in good agreement with those of Monte Carlo and Brownian dynamics methods. We may conclude from these results that if relatively coarse lattice systems are used, the translational and rotational Brownian motion of particles are reasonably activated. Hence, some modifications are necessary to the basic equations of the lattice Boltzmann method for using fine lattice systems in simulations of magnetic dispersions.