CFDEM®coupling - User Forum

Hi Chris,

i modified the OpenFoam solver pimpleDyMFoam where the CFDEM scheme is added. It works fine as the orginal solver cfdemSolverPiso, however when i changed in the dynamicMeshDict staticFvMesh ----> dynamicRefineFvMesh, to refine the mesh of certain field, it seems the locateModel can not find the particles after the mesh is refined.

So I wonder, how can we locate the particles in the new refined Mesh?

Best regards,

David

Hello everyone,

There is an error happened when I trying to run an example from tutorial as "--> FOAM FATAL ERROR:
Trying to use the dummy Pstream library.
This dummy library cannot be used in parallel mode

From function UPstream::init(int& argc, char**& argv)
in file UPstream.C at line 37.
--> FOAM FATAL ERROR:
Trying to use the dummy Pstream library.
This dummy library cannot be used in parallel mode

From function UPstream::init(int& argc, char**& argv)
in file UPstream.C at line 37.

Hi Chris,

I wonder how to access the trubulence visicosity nut(). For incomprissble flow, all force models
use:

const volScalarField& nufField = particleCloud_.turbulence().nu();

If a RAS model (e.g k-epsilon) is selected, should we conside thetrubulence visicosity in CFD-DEM? Lets say:

const volScalarField& nufField = particleCloud_.turbulence().nu() + particleCloud_.turbulence->nut();

Furthermore, if there is multi-phase fluid in the Domian, the visicosity is a mixtured value, e.g effective muf:

Everything goes well before I type "cfdemCompCFDEM" in the terminal. I can run both OpenFOAM examples and LIGGGHTS examples successfully.
But errors occur during the CFDEM compiling below:
##################################################################
/home/ciel/OpenFOAM/OpenFOAM-2.2.x/src/OpenFOAM/lnInclude/autoPtrI.H: In member function ‘const T& Foam::autoPtr::operator()() const [with T = Foam::clockModel]’:

Everything goes well before I type "cfdemCompCFDEM" in the terminal. I can run both OpenFOAM examples and LIGGGHTS examples successfully.
But errors occur during the CFDEM compiling below:
##################################################################
/home/ciel/OpenFOAM/OpenFOAM-2.2.x/src/OpenFOAM/lnInclude/autoPtrI.H: In member function ‘const T& Foam::autoPtr::operator()() const [with T = Foam::clockModel]’:

Hello everyone,

I met an error as "Cannot open mesh file ..DEM/b1.stl (input_mesh_tri.cpp:78)" when I run with "bash Allrun.sh". There is a stl file named as b1 in that package and it could run just with DEM. The code I used for importing wall is "fix cad1 all mesh/surface file ..DEM/b1.stl type 2". Is there anything I used to run the test? Does anyone met this error before? Thanks for any recommendation.

Hi CFDEMers,

I wonder whether it's possible to find the upstream and downstream cell index of a particle. I know the particle cellI is the particle's center sits.

For example, if I know the velocity at the particle center is in x positive direction, then the upstream cell is the neighbor one in negative x direction and the downstream one is the positive x direction.

Is there a good way to find the cell index? In addition, is it possible to get the velocity from the upstream one and distribute the momentum (impForces) to the downstream one? Please advise.

I need to model a slow-moving packed bed (particle size ranging from 10-40 mm) and counter-current gas flow. The hot gas heats up the solid particles which then undergo endothermic chemical reaction. I want to model this system as using CFD with the bed represented as a porous medium tuned to have the same CFD properties as an already-calculated (using commercial Rocky DEM software) bed of particles.

I already have such a CFD model in ANSYS CFX commercial software that models the chemical reactions, but the licence is expensive and I need to move to open-source CFD software.

Hi,

I am using all the files from a previous simulation of OpenFOAM in the start time folder of a CFDEM case.
The problem I am facing is that the uniform folder which is required to preserve previous RMS data is being overwritten by CFDEM solver and subsequently further RMS values are also incorrect. Can anyone please suggest ho to avoid this overwriting uniform folder?
channelFoam solver was not making these changes in the uniform folder.

I tried to work with diameter of particle about 20-100 microns, but I read here there are a limit because a precision machine issue and just I could work with 124 microns of diameter min in SI units. I changed my problem to CGS units, but I have some questions. In the example of tutorial ErgunTestMPI_cgs, the script Allrun.sh calls to controlDict_cgs_2.2.x and copy in other directory. It is necessary? What is it doing exactly ? .