CFDEM®coupling - User Forum

Hi,
I was wondering how can I run a case using explicitCoupling. I understand that implicit coupling provides better stability, but based on what I've been reading in the literature the explicit coupling is more accurate. So referring to the settling case tutorial, cfdemSolverPiso/settlingTestMPI, I made the following adjustments in constant/couplingProperties:

//--------------------------------------------------------------------
momCoupleModels
(
explicitCouple
//implicitCouple
);

I see that fvOptions are supported by cfdemSolverIB, or at least it appears to be the case from looking at the source code. Are there plans to add fvOptions support to cfdemSolverPiso as well?

I am trying to run a case of oscillatory flow using a tabulatedAccelerationSource in fvOptions to drive the fluid, which works with pisoFoam, but didn't do anything in cfdemSolverPiso.

Hi all,

Hi all, I'm running an unresolved simulation in which particles are injected in a Helle-Shaw like cell.
The cell has a variable (linear) inlet velocity, as showed below, and the particles are inserted using insert/rate/region.
inlet

{
type uniformFixedValue;
uniformValue table
(
(0.0 (8.0 0.0 0.0))
(9.0 (8.0 0.0 0.0))
(10.0 (0.0 0.0 0.0))
(11.0 (0.0 0.0 0.0))

);
}

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