(293a) Bubbling and Mixing of Gas-Fluidized Active Granular Materials

Active granular materials are particulates which can self-propel and do not contain time-reversal symmetry. For sufficiently large self-propulsion (i.e. active matter force), these materials are diffusive and self-fluidizing. Comparatively, for sufficiently small self-propulsion the system behaves similarly to non-active granular materials and bubbles rise through the system when operating above the minimum fluidization velocity. Here we use numerical CFD-DEM simulations to investigate the bubbling and mixing of gas-fluidized active granular materials at varying active matter force. The simulations reveal that the balance of drag force, active force, and gravitational force can be used to predict the transport regimes (sub-diffusive, diffusive, advective) of gas-fluidized active matter. The formation of granular convection rolls are also observed over time, despite no vibration in the system, and additional simulations are presented for varying magnitude active forces within the same system which may enhance the rate of segregation due to motility-induced phase separation (MIPS).