Several
discrete particle methods exist in the open literature
to simulate fluidized bed systems, such as discrete element method
(DEM), time-driven hard sphere (TDHS), coarse-grained particle method
(CGPM), coarse grained hard sphere (CGHS), and multiphase particle-in-cell
(MP-PIC). The main difference between these methods is in the treatment
of particle–particle interactions: by calculating collision
forces (DEM and CGPM), using momentum conservation laws (TDHS and
CGHS), or based on the particle stress model (MP-PIC). Here, these
methods are compared by simulating the same small-scale fluidized
bed with the same open-source code MFIX. The results indicate that
both modeling the particle–particle collision by TDHS and lumping
a few particles in a parcel increase the computation speed with little
loss in accuracy. However, the MP-PIC method predicts an unphysical
particle–particle overlap, which results in incorrect overall
bed hydrodynamics. These results suggest using the CGHS method for
fluidized bed simulations owing to its accuracy and efficiency.