Three-dimensional lattice Boltzmann simulation of suspensions containing both micro- and nanoparticles

In this paper, we present a three-dimensional lattice Boltzmann (LB) model to simulate suspensions that contain both micro- and nanoparticles. The microparticle dynamics is explicitly resolved by tracking individual solid particles, whilst the nanoparticles and base fluid are implicitly described as continua. The application of the LB model to simulate a micro spherical particle sedimentation in a microchannel and migration in a microtube filled with nanofluids show that the model allows the analysis of important parameters, including nanoparticle volume fraction, nanoparticle diameter, microchannel and microtube size. Finally, the model is applied to simulate particles in Couette flow. Through direct calculations of viscous dissipation, a mathematical correlation for viscosity as a function of micro- and nanoparticle volume fraction is proposed for the dilute suspension system.