CFDEM®coupling - User Forum

Hi all,

I have probably got a bug when running LIGGGHTS coupled with CFD. I found that the write_start command in LIGGGHTS does not work properly when they are working in parallel with CFD. Write_start works fine in single running of DEM, but it does not save any updated state when running through CFD. I suppose specialists of CFDEM project can shed a light on this issue.

Thank you,

Regards,

Nathan,

Hallo,

I am trying to understand the implementation of the different force models in CFDEMcoupling and to extract the applied definition of the "drag coefficient" Cd0.

Looking at SchillerNaumannDrag, for me everything is clear. The drag force is given by the following expression (compare SchillerNaumannDrag.C):

drag=0.125*Cd*rho*M_PI*ds*ds*magUr*Ur

and I get the "drag coefficient" Cd0=Cd

Looking at DiFeliceDrag, I can also follow the implementation (compare DiFeliceDrag.C)

Hi there,

I have a simple test case where cfdemSolverIB gives very different results for the steady state compared to simpleFoam. The velocity field is in pretty good agreement, but the pressure field is completely different. Am I missing something fundamental about pressure in the IB solver or did I make a mistake somewhere in the case setup? Any help would be greatly appreciated.

means that the CFD calculation based on the fixed DEM data field? Is it right?

I want to simulate the one-way coupling CFD-DEM simulation based on fixed CFD data field, so is there any way to achieve it?
(I already considered using LIGGGHTS only, but the proper implementation of drag force is not available.)

Thanks.

Hello!

First of all, I'm real CFD, DEM and Linux newbie.

But I got it to install OPENFOAM 3.0.1 with Paraview 4.4.0, LIGGGHTS 3.3.1 and CFDEM-coupling 3.0.1 on Ubuntu 16.04 (64 bit).
When I start a new terminal, I allways get this error message:

using CFDEM_ADD_LIBS_NAME=additionalLibs_3.0.1 .
!!! ERROR !!!: CFDEM_ADD_LIBS_DIR/CFDEM_ADD_LIBS_NAME=/home/denis/CFDEM/CFDEMcoupling-PUBLIC-3.0.1/src/lagrangian/cfdemParticle/etc/additionalLibs_3.0.1 does not exist.

Dear all,

We know that the unresolved CFD-DEM is applicable if the particle size is much smaller than the mesh cell size. However I'm not sure about the mesh cell size used in the following CFDEM's case studies shown here: http://www.cfdem.com/4-way-unresolved-cfd-dem

Dear all,
I am simulating the movment of two multi_sphere particles. my simulation run successfully but after I reinstalled CFDEM again, It does not work for my case and this error happens after finishing some time step. ( I did not change any thing atall)

Hello everyone,

I want to simulate particle settling in liquid and have doubt on which approach (resolved or unresolved) to use for following case ?

Particle diameter = d
Mesh height near to wall = h_w
Mesh height far from the wall = h_b

These parameters has following relation: h_w < d < h_b (i.e. Mesh height near the wall is smaller than particle diameter and Mesh height far from the wall is larger than particle diameter).

Hi, all-

In the tutorial case for cfdemSolverIB, we need to define phiIB in 0/ folder. I am wondering how we should define phiIB, e.g., corresponding to constant velocity boundary or constant pressure boundary.

Many thanks in advance!

Zhuang

Hi all,
I've just started using Ubuntu, and I'm finding it difficult to follow the procedure for installing liggghts, can anyone please guide me through the procedure involved in the installation of liggghts?
Thank you.