CFDEM®coupling - User Forum

I got a problem when I'm trying to couple Palabos and LIGGGHTS as shown below.

scons: Building targets ...
mpicxx -o showcaseRectChannel -Wl,--whole-archive lmp_fedora -Wl,--no-whole-archive showcaseRectChannel.o /home/jian/Documents/LBDEMcoupling-public/src/liggghtsCouplingWrapper.o /home/jian/Documents/LBDEMcoupling-public/src/latticeDecomposition.o /home/jian/Documents/palabos/lib/libplb_mpi.a -L/home/jian/Documents/liggghts/src -llmp_fedora

Hello, I modified an example from the directory "tutorials", and it works well, but when I visualize the results with paraview, the results obtained with OpenFOAM have an scale time from 0 to 0,4 seg (just as I set in the inputs files), while the results in LIGGGHTS have an scale time from 0 to 40 seg (which is not what I set in the LIGGGHTS inputs). The results are consistent, the computations are made in the correct times, but the VTK's generated by lpp, don`t have the information of time.

Hello guys,

I try to simulate very small particles with diameters about 1 micrometer.
Therefore I want to change my unit system from "SI" to another system.

I looked at the "ErgunTestMPI_cgs" tutorial, but some things are unclear to me:
If I change the unit system in DEM folder (in.liggghts; units), the unit system in CFD will also change. - Is this right?
(Otherwise I cannot understand why "g" in CFD/constant/ is set to 981.)

HI all,

1. I read the paper of Di Felice (1994) and found the drag coefficient correlation had Re = dp*magUr/nuf as the definition of particle Reynolds number (without the voidfraction term), but found the voidfraction term was coded in DiFeliceDrag.C. Could someone clarify?

Original Code in .C file:
// calc particle Re Nr
Rep = ds/scaleDia_*voidfraction*magUr/(nuf+SMALL);

// calc fluid drag Coeff
Cd = sqr(0.63 + 4.8/sqrt(Rep));

Hey,

I want to register the position of simulated particles. I found the position file (CFD/timestep/lagranian/particleCloud) and their coordinates.
E.g. it looks like this:

CFDEM®coupling version 2.6.1 released (released March 3, 2014)
by DCS computing GmbH
+works with OF 2.2.x (latest release commit: 61b850bc107bdd60bbf1bf9a6417b9faf701d128)
+...
+bugfixes

Now I can only download this version from here: https://github.com/CFDEMproject/CFDEMcoupling-PUBLIC
This is for OpenFOAM2.3.x. For some reason I should stick to OpenFOAM2.2.x.

So I need CFDEM 2.6.1, but where can I download it?

Thanks,.

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.