CFDEM®coupling - User Forum

Hello,

I'm new to OpenFOAM/LIGGGHTS and I'd like to use CFDEM for simulations of fluid-particle interaction with both momentum and temperature coupling between fluid/particle phases.

I am starting with the packedBedTemp tutorial with the cfdemSolverPisoScalar solver to understand CFDEM's out-of-the-box capabilities. However, I don't fully understand what is happening in this tutorial problem, and would be grateful for some insight on the following questions:

Dear Josef and Alice,

When re-run the ErgunTestMPI_cgs in the tutorial (CFDEM3.5), the foamToVTK to convert the output of CFD to VTK files reports an error as follows:

"--> FOAM FATAL ERROR:
floatScalar and/or label are not 4 bytes in size
Hence cannot use binary VTK format. Please use -ascii

From function foamToVTK
in file foamToVTK.C at line 335.

FOAM exiting"

This is possibly because the unit scalar has been changed and the format of output files became different.

Can you guide how to fix this ?

Hi all I'm running a case in which I use cfdemSolverIB with dynamicMesh. I used the twoSpheresGlowinskiMPI tutorial as a base case .
Everithing seems to be OK but suddenly the simulation crashes, below is the error message. I tried adjusting many parameters but nothing seems to solve the problem, if somebody can give me a hand would be great!
You can find attached the case.

Cheers,
Mauro

Time = 0.01315

Hi all,

I am trying to run multiple versions of CFDEM on one machine. I need them to run at the same time in order to use my simulation computer as efficient as possible. My first try was to create another Ubuntu-user and install the other version there. Unfortunately, this doesn’t work. OpenFOAM and LIGGGHTS alone run without any errors. CFDEM, however, gives the error message attached.

Hi all,

I am confusing about time in CFDEM modelling. For example, I set up the end time in Controldict is 0.2 s. Is this real time ? When comparing with experiment, it does not match. For example the experiment takes much longer time than 0.2 s to get the same condition as generated by simulation. Some published papers report their modelling results with total time 0.02 s for a 0.12x0.06x0.06 m box containing sand; this does not make sense to me at all.

Can some one explain about this ?

Thank you,

Regards,

Dear all
I have newly installed CFDEM and I want to know if my installation is correct.
I tried to run one of examples of tutorial via Allrun.sh in following directory:
~/CFDEM/CFDEMcoupling-PUBLIC-3.0.1/tutorials/cfdemSolverIB
but I have encountered these errors:

error: load: unable to find file ../../DEM/post/position_particle_1.txt
error: called from
postproc.m at line 11 column 5

Hi everyone

I am trying to compile LIGGGHTS-3.5.0 in cluster with following configuration:

************************************
ERROR from your CFDEM code!
ERROR: your OpenFOAM(R) version is not supported!
Please use a version that is supported, i.e., see the bashrc file in the source directory!
************************************

Dear all,
I modified the twoSpheresGlowonskiMPI Tutorial for the cfdemSolverIB such that the inlet and outlet are not fixed walls but patches with fixed velocity and fixed pressure, respectively. The two particles are inserted with flow velocity and move towards the outlet until the first particle is about to leave the region and be deleted. Then the error message below occurs.
I attached the case and would be very happy about any suggestions on how to fix this.

Thank you,
Tony

Hi,
I want to generate a compressed runtime log file. If I would have run say cfdemSolverPiso, then I could do something like
cfdemSolverPiso 2>&1 | gzip > log.gz

I was wondering how can modify the parCFDDEMrun.sh script, partly shown below to the same thing:
#- call function to run a parallel CFD-DEM case
parCFDDEMrun $logpath $logfileName $casePath $headerText $solverName $nrProcs $machineFileName $debugMode

Thanks!
Ali