CFDEM®coupling - User Forum

Hey guys,

I try to get a restart file every N timesteps.
If I add the command (in.liggghts_run)
write_restart ../DEM/post/restart/run*.restart
it writes one .restart file at the beginning.

Is there a possibility to write a restart file every N timesteps ?
E.g. like "write_restart ...... every N" or something like that.

It would help a lot.

Thanks for answering,
best wishes

Can anybody give me some idea about this?

Thank you so much!

Detian

problem solved
Thank you

Hi,

I tried to go through most of the forum topics but was unsuccessful in launching tutorial cases (fillCylinder and even cfdemTestTUT). Finally could not fix them. I think LIGGGHTS works perfectly fine but problem might be coupling with OpenFOAM
I had no errors in compiling CFDEM.
I attached two .txt files to this post, please have a look and help me out of this.

Thank you.

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.