CFDEM®coupling - User Forum

I used the defalut ErgunTestmpi solver to solve the bubbles(DEM particles) movement in water. I have set up the bubble's density as 1.225 in DEM/in.XXX file and the water's density as 998.2 in DEM/0/rho file, but I found the bubbles didn't move up in water under the buoyancy force effects. I have open the Archimedes forceModels in couplingproperties file.

I tried to use the insert/steam or insert/pack command to make the particle inject into the reactor by a certain velocity continuously, so I write these commands in the in.XXX file:

Hi cfdemers,

I've modified the tutorial cfdemSolverPiso to simulate cracks in some porous media filled with fluids.
The OpenFoam part with the changes I've made seems okay, but when I'm trying to modify the DEM file in.liggghts_resume I get some error :

Coupling...
LIGGGHTS could not find property radius to write data from calling program to.
ERROR on proc 0: This is fatal (cfd_datacoupling_mpi.h:160)

My problem seems to be that I'm changing the atom_style to atomic as I need to use a lj/cut pair_style. Here's what I've done :

Hi there, I am receiving the following error right when coupled run starts. I appreciate any help.

I'm a new cfdem user, about coupling intervals, I have several questions:

1. How to calculate its value?
2. In the DEM/in.XXX file, there is a command about coupling:
fix cfd all couple/cfd couple_every n mpi
what's the relationship between coupling intervals and value n. They are equivalent ?
3. The meaning of coupling intervals, I think it's:
run CFD $couplinginterval and then run DEM, the DEM step number defined in "run n" command in in.XXX file.
Is there anything wrong?

Thanks anyway,
Zhao

we have a tortuous micro-channel of varying cross-sections. we want to model the actual filtration of the particles when particle laden flow flows through the channel. for example the channel size is less then 1 micron and if the particle size is more then 1 micron, can it filter and model the deposition of particle.

Thanks
Lalit

when I run the liggghts, I can use insert/pack or insert/stream to insert particles continously. But when I run the cfdem case, it dose not work.

I don't kown the reason. I think it's because the coupling interval.

Thanks for any opion about insert particles contiously.

Thanks,
Zhao

Hi,

It's seems to me that bigParticles model is not managing well the calculus of voidFraction field with periodic BC or parallel computing. Indeed, voidFraction is not the same at each side of the boundary or between 2 processors.

In the image, it is voidfractionfield after first step of calculation where the rectangular mesh is divided in 4 processor (as a cross) and periodic at each side. One can clearly see the processor separation (orange cross) even if the particles are randomly distributed on the rectangle...

How to fix that ?

j

Hi,

I'll tried to upgrade from CFDEM-PUBLIC-2.1.0 to CFDEM-PUBLIC-2.1.1, everything works fine during compilation.
But when solvers compile, there's an error :

/usr/bin/ld: cannot find -llagrangianCFDEM-PUBLIC-2.1.1

So I tried to come back to previous OpenFoam version 2.1.0, by changing $WM_PROJECT_VERSION variable to 2.1.0, and recompiling, but now, I get the same error when compiling solvers:

/usr/bin/ld: cannot find -llagrangianCFDEM-PUBLIC-2.1.0

I made a: locate lagrangianCFDEM-PUBLIC and it eventually find a lib file :

Dear All,

When I am running "settlingTestMPI" on the Cluster the following Error apears:

Writing polyMesh
----------------
Mesh Information
----------------
boundingBox: (0.045 0 0.045) (0.055 0.05 0.055)
nPoints: 9261
nCells: 8000
nFaces: 25200
nInternalFaces: 22800
----------------
Patches
----------------
patch 0 (start: 22800 size: 400) name: atmosphere
patch 1 (start: 23200 size: 2000) name: walls
End

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