A cluster-based drag model of rough sphere for the simulation of fast fluidization

The non-uniform flow caused by cluster greatly influences the performance in fast fluidization systems. Rough particles result in extra energy dissipation by particle rotation, which finally affects the cluster formation and evolution. In this study, the kinetic theory of rough sphere (KTRS) is employed and coupled with the cluster structure-dependent (CSD) drag model to consider the rotation effect on cluster formation, where the total granular temperature is introduced and the cluster-scale effect on the collision is incorporated. The effect of particle roughness on energy consumption is also discussed. The result demonstrates that the cluster-scale pressure plays an important role in the collision. The energy consumption is dependent on the particle roughness or tangential restitution coefficient. Meanwhile, the change of particle roughness also alters mesoscale parameters like cluster size and cluster solid concentration.