Hello Users,
I am trying to solve pneumatic conveying system with dense solid flow regime (void fraction varies from 1 to 0.35), using CFDEM two-way coupled solver. The versions are OpenFoam 5.0 and LIGGGHTS-Public 3.8.0.
The simulation diverges with very high (1e+16) Courant number. The pressure and velocity numbers become unrealistic at timestep when Courant number increases unrealistically.
The simulation runs longer when CFD timestep and coupling interval are higher.
I keep DEM timestep fixed to 1e-5 seconds and change the CFD timestep as per CouplingInterval. T
(1) when CouplingInterval is 100 and CFD timestep=1e-3, it diverges after 18.9 seconds of simulation
(2) when CouplingInterval is 20 and CFD timestep=2e-4, it diverges after 3.8 seconds
(3) when CouplingInterval is 10 and CFD timestep=1e-4, it diverges after 2 seconds
The model settings in couplingProperties are attached in text file here.
Can you please suggest what could be the reason?
There is similar observation reported in link
https://www.cfdem.com/forums/optimal-coupling-interval-time
Thanks and regards
Tuks
| Attachment | Size |
|---|---|
 couplingproperties.txt | 3.7 KB |