Self-consistent particle simulation of model-stabilized colloidal suspensions

Abstract

Dynamics of model-stabilized colloidal suspensions were investigated by the self-consistent particle simulation method (SC), a new simulation algorithm that takes into account the interaction between the particles and suspending fluid. In this method, the fluid-particle interaction is introduced self-consistently by combining the finite element method (FEM) for fluid motion with Brownian dynamics (BD) for particle dynamics. To validate the reliability of the proposed algorithm, the shear dynamics of the stable particle suspensions were investigated. Relative viscosity and microstructure as a function of dimensionless shear rate at different volume fractions were in good agreement with previous observations. The robustness of the method was also verified through numerical convergence test. The effect of the fluid-particle interaction was well represented in simulations of two model problems, pressure-driven channel flow and rotating Couette flow. Plug-shaped velocity profile was observed in pressure-driven channel flow, which arised from shear thinning behavior of the stable suspension. In rotating Couette flow, shear banded nonlinear flow profile was observed. Although full hydrodynamic interaction (HI) was not rigorously taken into account, it successfully captured the macroscopic structure-induced flow field. It also takes advantage of the geometrical adaptability of FEM and computational efficiency of BD. We expect this newly developed simulation platform to be useful and efficient for probing the complex flow dynamics of particle systems as well as for practical applications in the complex flow of complex fluids.