CFDEM®coupling - User Forum

I am newer of CFDEM, recently I was confusing about the differences between "couplingInterval" and "couple/cfd couple_every".
"couplinginterval" locates in CFD/constant/couplingProperties, and "couple/cfd couple_every" is in DEM/in.liggghts_run
both of them are about the coupling properties of CFD-DEM calculation, but what's the difference between them?
Thank you very much!

Hello,

I am using bigParticle voidFraction model. For that grid size and particle size are equivalent. In couplingDictionary parameters are gives as:
porosity 64.0
weight 0.051625

cfdemCoupling runs nicely but per cell voidfraction doesn't change that much. When I have looked inside the source code, particle volume is multiplied by weight. I didn't get why volume is weighted by weight parameter? For the weight I am giving it reduces the particle volume so I have tried with weight of 64 but with this simulation doesn't run, courant number reaches very high.

Hi All,

I am in the early stage of CFD-DEM and trying to find the best tool to conduct my research in the fields of solid particles. I am wondering what can be the best choice between CFDEM (OPENFOAM+LIGGGHTS) and original Lagrangian solvers of OpenFOAM? It seems that with LIGGGHTS the computational process can be much faster. Is that true?

Thanks in advance for your advice.

Hello everyone,

is it possible to use the LIGGGHTS features "deforming meshes" and "stress controlled wall" also in CFDEM based simulations? Or is these only limited to LIGGGHTS only simulations?

Thank you all and Regards,
Patrick

Hello everybody
I want to simulate oil spill in sea water that contains ice. what kind of methods you propose?
Regrads

Hello everyone,

I want to simulate a 4-way coupled case with mesh motion. Does the public version of CFDEM supports GGI mesh motion feature ? If not, would it be possible to simulate this case in public version of CFDEM ?

Thanks and Regards,
Aashish Goyal

Hi, everyone

Hello，
I‘m a beginner of CFDEM®coupling and only have experience of Openfoam. I wanna simulation the solid-liquid two-phase flow in a pipe by CFDEM®coupling. Is there any case of solid-liquid two-phase flow in a pipe?
I am confused about the mesh import in the cfdem case. It's same with openfoam?
And It seems that in all tutorial example, parallel operations have been taken and the meshes have been split. Can I run the case sequential and how?
Thanks,
Scoop

Dear all,

recently, I faced a problem with CFD-DEM coupling.
both in.liggghts_init and in.liggghts_run need to define "mesh/surface" . I defined wall using STL files located in folder "meshes", the commends are as follows:
fix cv all mesh/surface file meshes/wall.stl type 1 #surface_vel -4.5 0. 0.
fix bx all mesh/surface file meshes/inlet.stl type 1
fix inface all mesh/surface file meshes/outlet.stl type 1
fix wall all wall/gran model hertz tangential history mesh n_meshes 2 meshes bx cv

Hello,

I'm trying to solve the heat transfer problem for a static particle bed with interstitial air. The particles are bigger than the mesh used for the CFD solution. From the source code, I see that the heat exchange field (EuField in cfdemSolverPisoScalar.C or the Tsource in cfdemSolverPisoScalar.C) is just being added to the CFD cells that coincide with particle centroids. But Tsource in all the other cells that also occupy this particle is being taken as zero.

I am wondering why not use a smoothing model to distribute this Tsource?