Lattice Boltzmann for Colloids in Binary Fluids

The implementation of solid colloidal particles suspended in a binary fluid mixture via the lattice Boltzmann method is described. To represent colloids in a binary mixture, boundary conditions for mass and momentum at the solid-fluid interface are extended to include a conserved compositional order parameter. The parallelisation of the fluid-particle problem is addressed, and its scaling investigated. In particular, a numerical bottleneck at high solid volume fraction related to the inclusion of lubrication corrections between closely separated particles is considered, and shown to be particularly acute in the binary fluid problem. Potential workarounds to address large system size and large numbers of particles are discussed.