Application of the kinetic theory of rough spheres to the simulation of the hydrodynamics of particles and liquid phases in a fluidized bed

Abstract

The flow behaviors of liquid and particles in a fluidized bed are simulated using a liquid-solid two-fluid model, coupling with the kinetic theory of rough spheres. The expressions for the energy dissipation and viscosities of particles are adopted as functions of the tangential restitution coefficient and the restitution coefficient of particles, which consider the effects of particle rotation on the exchange and dissipation of particle energy. The simulated bed expansion height, particle concentration, particle velocity and total granular temperature differ from those not considering particle rotation. According to the simulation results, particle rotation enhances particle aggregation and decreases the bed expansion height, particle axial velocity and total granular temperature. The energy dissipation that is produced by particle rotation constitutes approximately 25% of the total energy dissipation in a liquid-solid system. In addition, two factors that affect particle rotation are explored by changing the tangential restitution coefficient of the particles and the liquid velocity. The simulation results demonstrate that the particle rotation effect is the most significant at β = −0.2, and the particle rotation is enhanced with the increase in the liquid velocity.