CFDEM®coupling - User Forum

Hey guys,

I try to simulate a channel with a lot of particles. The simulation runs without any errors, but the particles run off while arriving the wall.
Is there a command which preserves the particles on walls ?

Thank you

EDIT:
I found something in the forum that the youngsModulus has to be high enough and the timestep should be low.

Hi all,

I am currently using CFDEM2.7.1 with LIGGGHTS 3.0.7. I want to try with higher version CFDEM2.9.0 coupled with LIGGGHTS 3.1.0 or LIGGGHTS 3.2.0. How can I do compiling the new version CFDEM2.9.0 without any influence on my current CFDEM2.7.1. In other words, I would like to keep both versions of CFDEM work in parallel on the same computer. I think modifying variables can enable this. Any hint, please.

Thank you,

Regards,

Hey guys,

I try to simulate with cfdemSolverPiso. If I start the "Allrun.sh" file the simulation runs, but doesn't create a controlDict.foam file to watch in paraview.
I think the problem is, that while finalizing the process there is following error message on screen (there's no postProcessing folder created):

*** error: could not open "../postProcessing/probes/0/p" ...

Does somebody knows how/where to fix it ??
Idea's would be great.

Thanks for your help :)

Dear CFDEM developers,

I am new to the CFD-DEM coupling, and doing a simulation of fluid flush on big particles. The big particles are modeled with overlapping spheres method in LIGGGHTS. The problem for the CFD-DEM coupling is: due to the overlapping volume of spheres, the sum volume of all spheres is about 200% - 300% of original particles, therefore in CFD model the void fraction of fluid is extremely low - e.g. 0.1, and the simulation blows up in few seconds.

Hello everyone,

I have just recently installed the latest version of CFDEM, Liggghts and OpenFoam 2.3.x. The installation run very smoothly but when I tried to run the tutorial examples I get some errors .

Just to know, with the previous CFDEM version I didn’t get these errors.

I think the error started with the following statements (for ErgunTestMPI exampe ) :

Dear CFDEM forumers,

Recently, I am trying to simulate a case with sediment transport, before the simulation, I tried a case to see whether the force, velocity and position are right for a single particle, there is a very stranger thing that, the coupling interval will affect the velocity.

Hi everyone,

recently there were some posts concerning the compatibility with the latest OF.
Finally I had time to take a look at the compilation issues.
The following changes in some options files should get the compilation, although some warnings remain.
This is a workaround until it gets released.

In applications/solvers/cfdemSolverPiso/Make/options and cfdemSolverPisoScalar/Make/options add the following lines:
In EXE_INC =
-I$(LIB_SRC)/meshTools/lnInclude

In EXE_LIBS =
-lmeshTools

I am wondering if anyone compares the implementation of gas-solids coupling in these two codes. I got quite different results for the same problem. Attached is a snapshot comparing the two simulations. Any comments will be appreciated. Thanks.

Tingwen

Hello all,

Hi all,

I'm running a simulation with CFDEM 2.7.1 to model particle fluidization in a cylinder fluidized bed. The bed dimensions are: 15 cm diameter and 22.5 cm tall. In my fluidized bed, I have near 600,000 particles (particle size 1.5 mm diameter). Two runs were setup with 32 and 64 CPUs. The computation is really slow in either 32 or 64 CPU cases. I checked the log file and found out the problem is in the coupling process between OpenFOAM and LIGGGHTS. In each coupling, it approximately takes more than 10 minutes to finish. Is it normal in this situation?