5.4 CFD-DEM Coupled Simulation and Development
331
Fig. 5.75 Initial packing of the spouted bed (a) and initial void fraction field with smoothed void
fraction method (b, c) and particle-divided finite volume method (d, e, f) under different cubical
cell sizes
There is no heat transfer in the particle–fluid system, so only particle motion and
fluid flow are simulated in the CFD-DEM simulation. The velocity inlet boundary
condition is set at the bottom for three channels. The top is an outlet, and the others
are non-slip walls. The time steps are 1.0 × 10
−5 s and 2.0 × 10
−5 s for particle and
fluid flows, respectively.
At t = 0, the packing of the bed is shown in Fig. 5.75a, and the void fraction in
cubical cells (Δx = Δy = Δz) calculated by the Smoothed Void Fraction Method
(SVFM) is shown in Fig. 5.75b (Δx = 0.83d p ) and Fig. 5.75c (Δx = 0.42d p ). For
comparison, Fig. 5.75d (Δx = 1.67d p ), Fig. 5.75e (Δx = 0.83d p ), and Fig. 5.75f
(Δx = 0.42d p ) show the void fraction using the particle-Divided Finite Volume
Method (DFVM). It can be seen that the void fraction in SVFM is 0 in the upper bed
331
Fig. 5.75 Initial packing of the spouted bed (a) and initial void fraction field with smoothed void
fraction method (b, c) and particle-divided finite volume method (d, e, f) under different cubical
cell sizes
There is no heat transfer in the particle–fluid system, so only particle motion and
fluid flow are simulated in the CFD-DEM simulation. The velocity inlet boundary
condition is set at the bottom for three channels. The top is an outlet, and the others
are non-slip walls. The time steps are 1.0 × 10
−5 s and 2.0 × 10
−5 s for particle and
fluid flows, respectively.
At t = 0, the packing of the bed is shown in Fig. 5.75a, and the void fraction in
cubical cells (Δx = Δy = Δz) calculated by the Smoothed Void Fraction Method
(SVFM) is shown in Fig. 5.75b (Δx = 0.83d p ) and Fig. 5.75c (Δx = 0.42d p ). For
comparison, Fig. 5.75d (Δx = 1.67d p ), Fig. 5.75e (Δx = 0.83d p ), and Fig. 5.75f
(Δx = 0.42d p ) show the void fraction using the particle-Divided Finite Volume
Method (DFVM). It can be seen that the void fraction in SVFM is 0 in the upper bed