CFDEM®coupling - User Forum

Hello Everyone, I want to simulate a bubble column which bubbles spray out from a gas distributor into water.

Bubbles were considered as the discrete phase and their flow behaviour was simulated using DEM. The water phase was continua phase which was simulated using Euler method. The diameter of bubbles was supposed to be a constant(5mm).

I want to use Herz-Mindlin Granular contact model to complete the simulation. I just consider the bubbles the same as any other solid particles simply.

Can I use liggghts to simulate the bubbles contact?

Hi

My log files end up being really big (~10GB) and I don't find any use for the "log.liggghts" file that is output to the /case/CFD/ folder.

Is there a setting that stops this file from being created?

Thanks
Evan

Hello, I'm studying the flow above a wing, for a project of ice accretion. For this work it is necessary to study the water particle tracks. Should you advice the CFDEM method? Could you indicate me a link that explain how to use CFDEM method?
Thanks.

Best regards.
Mattia Garabelli

Hi,everyone!
I want to define a new drag model and use it in my simulation.

here's my steps:

1 I made a new directory named 'Newdrag' in ../submodels/forcemodel, and wrote my Newdrag.C and Newdrag.H there.

2 Then I modifiled 'files' in ~/CFDEM/CFDEMcoupling-PUBLIC-2.1.1/src/lagrangian/cfdemParticle/Make(just add an item '$(forceModels)/NewDrag/NewDrag.C' after item '$(forceModels)/GidaspowDrag/GidaspowDrag.C )', and ran 'wmake' at ../~/CFDEM/CFDEMcoupling-PUBLIC-2.1.1/src/lagrangian /cfdemParticle to compile the NewDrag.C.

Hi,

I read in the documentation for the bigParticle voidfraction model that:

The bigParticle voidFraction model is supposed to be used when a particle (or it's representation) is bigger than a CFD cell. The voidfraction field is set in those cell whose centres are inside the particle which results in a stairstep representation of the bodies within the mesh (i.e. voidfraction is either 1 (fluid) of zero (solid)). For archiving accurate results, approx. 8 cells per particle diameter are necessary.

Hi,

May I ask a question about the momentum transfer between solid and fluid phases?

Where can I specify the range of the forces included for momentum transport from solid phase to fluid?

Is MeiLift included? Could anyone give me a clue?

Thanks.

rq

Hi cfdemers,

I modified ErgunTestMPI case to my numerical setup. I only changed the geometry in polymesh and boundary conditions in 0.
But I found the command fix couple/cfd is needed.

Could anyone tell me when this command is needed and where I can specify it?

Thanks.

rq

Hi,

Does anyone know where I can specify the LIGGGHTS is reading from in.liggghts_init or in.liggghts_resume?

update: I found the answer. It's in CFD/counstant/couplingProperties

Thanks.

rq

I have been trying to compile CFDEM for some time now but I just can't seem to get it to compile. I am working on a Scientific Linus 6.3 system and following the instructions from this site in the CFD-DEM>Downloads page. OpenFOAM 2.1, ParaView 3.12, and LIGGGHTS current git clone all compile without errors. OpenFOAM and paraView test out correctly. Executing the cfdemCompCFDEM command leads to this error:

...POSIX/lnInclude -fPIC -c $SOURCE -o Make/linux64GccDPOpt/readLiggghtsData.o
/usr/bin/ld: cannot find -lmpi_cxx
collect2: ld returned 1 exit status

Both OpenFoam and LIGGGHTS is installed and run OK.
When I compile CFDEM by using 'cfdemCompCFDEM', I get a error which I shown as below.

2012/11/17 Updated +1

cgoniva‘s reply in some topics hint me to re-compile Liggghts by using cfdemComLig again, then the problems solved.

Thanks again.

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2012/11/07 Update:
The problems refer to MPL_XXX is solved.
However, there is another problem as shown below.