Advanced CFD simulation has been regarded as one of important tools for dealing with the complicated non-linear fluid dynamics in the fluidized beds. Different momentum balances of particles and fluid phases in Eulerian-Eulerian models have been proposed due to different opinions on fluid-particle and particle-particle interactions. Particle viscous force

solid pressure force and inter-phase drag force are discussed in this paper. Then

authors provided a simple hydrodynamic model based on the two-fluid theory

which considered the effect of discrete particles on both the fluid- and solid-phase momentum equations under a quasi-equilibrium state. One of its main features is that the characteristic length in the model is of the order of the particle diameter. Numerical simulations were conducted in the platform of a commercial software package

CFX 4.4

by adding user-defined Fortran subroutines. After the independence of grid size

time step and the maximum solid volume fraction were explored

case studies including homogeneous fluidization of liquid-solid system

homogenous/aggregative fluidization of Geldart A particle and bubbling/collapsing/jetting fluidization of Geldart B/D particle for gas-solid system were conducted in 2D/3D fluidized beds. The majority of results were compared with classic theories

experimental data and simulations in the literature and good agreements were obtained

which indicates that this model can be used to predict the fluid dynamics of the dense particle-fluid two-phase flow in the fluidized beds.