5.4 CFD-DEM Coupled Simulation and Development
329
Fig. 5.72 Flow diagram of
calculating the void fraction
field in CFD-DEM
simulation. Note i and j are
the index of particle and cell,
respectively. p i and c j are
the center position of particle
and cell, respectively. r i is
the particle radius. n is the
particle number
5.4.3.3 SVFM Model Validation
An experimental spout fluidized bed [125] is selected for validating the CFD-DEM
framework with the Smoothed Void Fraction Method (SVFM). The spout fluidized
bed is usually simulated with a particle-Divided Finite Volume Method (DFVM),
where the cell size is about 1.5–3.0 d p [125–127]. In the current SVFM, the subparticle scale mesh is applied, i.e., (Δx, Δy, Δz < d p ). The spout fluidized bed is
a thin rectangular box and filled with 12,000 spherical glass particles of 3.0 mm in
diameter at the initial time. The spout air is injected into the bed at the bottom by
three parts. The background velocity u b is 2.4 m/s, and spout velocity u sp is 43.5 m/s.
More details of the experiment can be seen in [125], and the structure of the bed is
shown in Fig. 5.74.