CFDEM®coupling - User Forum

Hi, All:

Dear CFDEMers,

I set up a case with dynamic Smagorinsky LES model, but I found one thing that, with the smooth case, LES model can give great result, but if I put one layer of sediment (fixed at bottom), the LES model still give the shear velocity u* like smooth wall, but the RANS model (komegaSST model) can recognize the particles and give a larger shear velocity which is close to the experiment.

Has anyone has met the same problem and could give me some advice on this?

Thank you so much!

Detian

hello cfdem community,

i'm trying to run the command cfdemCompCFDEM to couple CFDEM with OpenFOAM-2.4.0 and it doesn't seem to work. Besides the RASModel.H and ompi/ error, the compilation gets stopped at /usr/bin/ld: cannot find -llagrangianCFDEM-PUBLIC-2.4.0. I've attached 3 logs file for your inspection. I've changed a few variables in ~/.bashrc as follows:

Problem Solved

Hi all,

I have a problem running the tutorial case ErgunTestMPI with the following transport property.

transportModel HerschelBulkley;
nu nu [ 0 2 -1 0 0 0 0 ] 1e-04;
rho rho [ 1 -3 0 0 0 0 0 ] 1000;
HerschelBulkleyCoeffs
{
nu0 nu0 [ 0 2 -1 0 0 0 0] 1;
tau0 tau0 [ 0 2 -2 0 0 0 0 ] 1e-03;
k k [ 0 2 -1 0 0 0 0 ] 1e-06;
n n [ 0 0 0 0 0 0 0 ] 1;
}

Hi All,

I have a question about the fix freeze command in CFDEM coupling, as I found it's behavior is different from what's described in the docs (or, I'm doing something wrong, please help me with this:-() . I define particles in a region near the bottom to be type 2, and the other particles to be type 1. in the DEM part, I used the following line to freeze the particles of type 2:

......

group bottom type 2
group active type 1
fix 2 bottom freeze
velocity bottom set 0.0 0.0 0.0 units box

Hello guys,

I want to simulate a small channel (11 micrometers) with small particles (2 micrometers).
Therefore I chose the "CGS" unit system. I tried to build a model with a 11 cm channel and 2 cm particles and it works fine.

But when I scale my region, neighbor, scaling coefficients, velocities, radiuses, blockMeshDict; it doesn't work anymore (Courant number rises very quick).

Dear all,

Recently I have read the code of virtual mass force, but there is a question that:

the original force = 0.5*rho_f*V_p*(Du/Dt-du_s/dt)=0.5*rho_f*V_p*(du/dt+u*div(u)-du_s/dt)

is that means in our virtual mass force model we use:

if splitUrelCalculation, using (Du/Dt) instead of (Du/Dt-du_s/dt),

if not splitUreCalculation, using (Ur-Urold)/dt instead of (Du/Dt-du_s/dt).

Is my understanding of this right?

Thank you!

Detian
2015.7.18

I think all went well installing LIGGGHTS along with CFDEM

so happy after more than 15 days day and night :)

the only problem is that I can't see the results (postprocessing) I don't have matlab
and octave seems to not work well to be called it show many errors
i some one could help little I can go faster

here what I get when running
tutorials/cfdemSolverPisoScalar/packedBedTemp

every thing went well

till here postprocessing i think

Hello,
I ran some examples from Palabos and LIGGGHTS and both softwares work fine separately. I followed all the instructions from https://github.com/ParticulateFlow/LBDEMcoupling-public. Unfortunetely I got some errors (see attached screenshot or text file). Does anyone know how to fix it? I am working on macosx 10.10.

Regards,
Mateusz