A two-fluid model for powder fluidisation in turbulent channel flows

This study uses computational fluid dynamics to model powder fluidisation in a turbulent channel flow. A two fluid model is adopted for simulations. Closures are provided through the kinetic theory of granular flow where particle energy fluctuations are captured through granular temperature. Simulation results are compared to the experimental evacuation time data for a lactose carrier powder across different inlet Reynolds numbers. Different turbulence closures were tested, with the k-epsilon RNG model most aligned to experimental data. The effects of packing limit, coefficient of restitution and turbulence dispersion were also studied. Results show that the inlet turbulence intensity and dispersion models have marginal effects on evacuation, whereas maximum packing limit significantly influences powder fluidisation. The two-fluid model generates excellent agreement with the experimental data for all tested Reynolds numbers. Additionally, powder size distribution is studied, with results showing no significant difference in evacuation time between monodisperse and polydisperse particle size distributions. (c) 2021 Elsevier B.V. All rights reserved.