Dear CFDEM community,
Currently we are simulating particle-laden flow in a pipe using DNS-DEM or LES-DEM. The coarse particles we are using are bigger than the CFD cell. When considering the unresolved approach, we tried the GaussVoidFraction model, but got the following error
Selecting voidFractionModel Gauss
W A R N I N G - do not use in combination with differentialRegion model!
[2]
[2]
[2] --> FOAM FATAL ERROR:
[2]
This model does not yet work properly - Eqns need to be revised!!!
Is the GaussvoidFractionModel working properly in the released v3.8.0 or is there any special requirements to use this model? Any suggestions on calculating the void fraction when the particle is bigger than the CFD cell? Thanks.
Cheers
Enzu
alice | Mon, 01/29/2018 - 10:19
Hello Enzu,
Hello Enzu,
generally unresolved CFD-DEM is not designed for cases in which particles are bigger than mesh cells. The basic equations are simply not valid in such cases. Depending on how big the particles are (do they cover aproximately one cell or perhaps more) it might still be possible to run the simulations, however, the correctness of the results has to be validated. The GaussVoidfractionModel has not been modified for a while...
In case the particles cover more than one cell in total I would recommend to changing to resolved CFD-DEM anyways (which of course is quite a bit more expensive...).
Best,
Alice