Simple Diffusion Hopping Model with Convection*

The transportation of matter in particulate systems has been the subject of significant computational study using a variety of approaches such as particle hopping models. While hopping models fully describe particle diffusion, these models do not capture convective particle motion.
In this study, we present a new variant of a diffusion-hopping model, the convective diffusive lattice model, to model particle flows near bluff obstacles. Particles interact on a square lattice and are subject to excluded volume conditions. In an extension to previous models, we use a continuous velocity field to mediate the particle positions during a convective update after which particles also diffuse. We show an expected wake behind a square obstacle and for larger objects we observe recirculation zones with symmetric vortices in qualitative agreement with experiment and previous simulations.