CFDEM®coupling - User Forum

Hi,

first of all I want to thank you for the real great work which makes my life somehow easier. I already worked with the first release of the coupling without any problems but with the current version I ran into some.

Well, if I install openfoam and paraview like described they are located in the /opt folde. Hence, I changed the owner and work in the /opt folder. Downloading LIGGGHTS and CFDEM was no problem, compiling LIGGGHTS was easy, too. But when I try to compile the CFDEM I receive the following error after a couple of files were compiled succesfully:

Hello,
I am trying to wmake the cfdemParticle src. However the twoWayMPI.H file tries to include library_cfd_coupling.h. According to the comments, it should be in the LIGGGHTS src, but I cannot find it. I successfully installed LIGGGHTS yesterday with the latest distribution. It's a wonderful program.
Thanks for your help.
Mark

Hi Chris,

Thanks for releasing this wonderful CFDEM 2.0!

I just want to know the LIGGGHTS lib name, and I use:
CFDEM_LIGGGHTS_LIB_NAME=lmp_ubuntu

It seems to be not right, because I got:
/usr/bin/ld: cannot find -llmp_ubuntu

when I wmake libso.

Thanks a lot!!

Best,
Tong

Hi,

I found

"fix cfd all couple/cfd/force couple_every 100 mpi"
has to be changed to

"fix cfd all couple/cfd/force every 100 mpi"

in DEM/in.liggghts_init

rq

Hi Chris,

I feel sorry to disturb you, but I noticed that there are several comments in the input file of DEM:

#force : f_couple_cfd[0] f_couple_cfd[1] f_couple_cfd[2]
#node : f_couple_cfd[6]
#cell id : f_couple_cfd[7]

How do I output the drag forces and cell id of each particle together with dump in liggghts?

Thanks a lot for your kind help!

Best,
Tong

I am trying to set up a simulation similar to the partly fluidized bed examples on the CFDEM example page. Were those examples run using the same code as was released?
I find that when the particles get that close together the CFD simulation quickly gets very high and unrealistic velocities and crashes.
Reducing the timesteps does not seem to help.

Any suggestions?
Thanks,
Alexa

Hi,
Can I Use New Drag Correlation instead of the Yu et. al correlation used in the CFD- DEM approach, for fluidised beds, and Since I'm new to both LIGGGHTS and Linux can you guide as to where and how this modification be made.

Thanks,
Kshitij

Hi cfdemers,

I added the command
lattice sc 1
in order to add more particles randomly in settlingTest by
create_atoms 1 random 10 1 NULL units box

However, I got an error message in DEM log file

// run_cfdemSolverPisoExplicit_settlingTest_DEM //

/mycfdem/settlingTest/DEM

LIGGGHTS 1.1.10 based on lammps-10Mar10
Created orthogonal box = (0 0 0) to (0.1 0.1 0.1)
1 by 1 by 1 processor grid
Lattice spacing in x,y,z = 1 1 1
ERROR: Illegal create_atoms command

Any idea?

Thanks.

Ruo

Hi,
I am trying to run a simulation like the paddle mixer from the CFD-DEM page. The GGI is included in the 1.5-dev but not in the 1.6 of OpenFOAM, so I tried to compile the solver with 1.5-dev but it doesn't work.
How was the paddle mixer setup?
Thank you
Stephan

Hi, Chris!

I have coupled the interDyMFoam solver with LIGGGHTS by using you framework that has previously done in icoFoam solver. However, as you may know, I just modified the UEqn.H and pEqn.H by adding the fp term and the main cpp file interDyMFoam.c by adding the do particle stuff sentences.

However, I am not sure if it is correct because although the impact of fluid on particles is realistic, the impact of particles on fluids is not that good.

Do I need to modify other .H files such as the alphaEqn.H? If yes, how? Just deduct the alpha value by the void fraction?