Modelling of Gas-Solid-Liquid Flow and Particle Mixing in a Rotary Drum

Solid-liquid rotary drums have been widely practised in various industries,while the complex multiphase hydrodynamics hinders the understanding and optimization of these processes.in this work,the computational fluid dynamics-discrete element method coupled with a volume of fluid is developed to describe the gas-solid-liquid flow and mixing in a rotary drum including inter-particle collisions,inter-phase interactions and interface morphology. A smoothing method is used to link the quantities between the particle and computational grids,allowing the fine grids to resolve flow details such as the interface and curvature.The effects of liquid presence and rotating speed on particle-scale behaviors (e.g.,repose angle,active-passive zone,solid residence time and force chain) and the mixing performances such as mixing index and dispersion are studied.The results show a positive correlation of the active depth,mixing degree and particle dispersion with the rotating speed.The liquid presence leads to a deeper active depth,prolonged solid residence time in the active zone,and lower contact force.Thw work sheds light on the design and process optimization of rotary drums.