CFDEM®coupling - User Forum

Hello

I know that it is the basic assumption and a prerequisite in unresolved CFDEM that the particle diameter must be smaller than CFD cell size. It is recommended that that cfd cell should be around 10*particle diameter.

Hello Community

I am facing a problem where I am not able to provide periodic boundary at STL boundaries which are inside the larger simulation box. In the CFD side, I am providing the cyclic bc at inlet and outlet of stl geometry. However, In DEM side, I cannot find any option where I can provide periodic bc at inlet and outlet STL boundaries. As per my understanding, in the liggghts scripts, we define boundary type of simulation box, not of STL boundaries. I looked in the portal but could not find the answer. I wonder, if I can do it anyway?

Hi, experts,
Recently I try to couple cfdem inserting superquadric models. But the error always shows in my case like "ERROR on proc 0: Using default surface model for non-spherical particles! (../surface_model_default.h:144)" .
After I seeking for the code, it told that
"if(sidata.is_non_spherical)
error->one(FLERR,"Using default surface model for non-spherical particles!");"
I am a little confused about the meaning of the "sidata". Could anyone give some explanation and advice .

Thx so much,
Clyde

Hi Guys

Does anyone have any advice for modelling deck of vibrating screens?

I have developed a mesh 2x1.8m with 12.5mm apertures in it.

I get the below error when trying to run my code.
what can I do to resolve the issue?

Hi

Dear everyone
I am working a soil scour problems, recently, I found a modified version of CFDEM with multiscale CFD/VOF-DEM solver developed by Linhan Ge called CFDEMCoupling-LG. However, when I installed it according to the Installation procedures provided in "readme" file, all the tutorials can not run well including the tutorials of the original CFDEM version. Has anyone ever encountered such a problem？
Zhang Peiyun
Tongji University

Hi all,
I am recently doing research on the CFD-DEM importing superquadric models. Everything is good in the liggghts after I modified some codes as shown in the official announcements, and I successfully finished the superquadric particles packing in the DEM side. However, when I turned to the CFD side and runned CFD, it told "invalid atom style". I tried some ways(such as set "superquadric_flag = 1" in atom.cpp),but it seems of no use. Could anyone give some advice?

Thanks,
Clyde

Hi,
I am looking at the KochHillDrag formulation and have experienced that a variable called "SMALL" is used. However, I have not yet found out what the value of the variable "SMALL" is? I would expect it is just a "small" number, but I am not able to find the exact value?

I hope someone can help me.

Cheers,
Jeppe

Hi all

I am a beginner of CFD-DEM and the particle shape in my simulation is ellipsoid. I am quite confused that what adjustments do I need to make to complete my simulation？

As far as I konw, I need to add new drag force, lift force etc. in the forceModel folder. Is there anything else that needs to be adjusted in CFDEM?

Hello Community

I am facing this strange error when performing CFDEM simulation. I prepare gravel bed in channel cavity by performing pure DEM simulations and then use restart file written in pure DEM simulation to perform a coupled simulation. At the very first time CFD time step, I get error mentioning that Message from processor XX is not fully consumed. I have looked online if someone has faced similar problem but I cpuld not get any similar post. More specifically the error says: