CFDEM®coupling - User Forum

This is a forum dedicated to CFDEM®coupling using the LIGGGHTS® DEM code and OpenSource CFD.

Velocity under stationary particle

Submitted by Kinaci on Wed, 02/25/2015 - 15:05

Hi everyone,
I am trying to simulate a flow around a single stationary spherical particle, using IBM method. With force models ShirgaonkarIB and ArchimedesIB. However there seems to be a problem with the coupling data, eventhough the particle isn't moving, when I check for flow velocity in paraview, the velocity where the particle is located does not go down to zero. Does anyone have any ideas about why it can be? Is it because of the coupling properties that I use or is it because of numerical reasons that it doesn't become zero? Did anyone else have this problem?

High velocity and scattering of particles

Submitted by elham.nasiri on Fri, 02/13/2015 - 19:24

Hi all,
I'm simulating the sediment transport with my solver(interFoam+liggghts). But I did not succeed yet!
The velocity in inlet and outlet of channel in vicinity the particles became very high!
I guess some subjects:
- properties of particles OR different properties of particles before and after insertion!
- I don't know why Solving for p_rgh didn't stop in terminal after timeStepFraction()=1 !?(Please see below)

Courant number divergence

maurobaldini's picture
Submitted by maurobaldini on Fri, 02/13/2015 - 18:19

Hi everybody, I'm running a simulation of particles inside fluid and I'm having problems with the Curant numbre (C-n) value.
When I create the setup for the CFD simulation I adjusted the OpenFOAM timestep to keep the C-n less than 1, I understand that the Courant number It's afected by the mesh size, the value o U and finally the timestep. I checked the CFD simulation and everything it's ok.

Convert SI to CGS Unit in CFD

Submitted by NTT1508 on Wed, 02/11/2015 - 09:24

Hi all,

I am doing CFDEM coupling for significantly small particle size (50micron) that is suggested to use cgs unit. Thank to CFDEM project team for making a case tutorial in terms of cgs unit, I have found and tested tutorials ErgunTestMPI-cgs. I also tried and compared the same cases with and without copying ControlDict file to .OpenFOAM directory. It is surprised to see that the results in both cases (with and without Unit conversion) are not different. Note that I did not change anything in the ErgunTestMPI-cgs tutorial except disabled ControlDict file.

Issues with compiling CFDEMcoupling 2.7.1 with CentFOAM-2.3.x

Submitted by alberthappy on Mon, 02/09/2015 - 17:29

Dear everyone,

First of all, Thanks to all those devoting their time and endeavor to the development of open source software like CFDEM and those helping others to learn and explore the use of the software. I learn a lot from this forum.

Basically, I follow the tutorial to install the CFDEM coupling. The OpenFOAM version that I use is CentFOAM-2.3.x, which is easier to compile. And I'm using a server that I don't have root permission. I installed CentFOAM in /local/

Issues with CFD - DEM synchronization

maurobaldini's picture
Submitted by maurobaldini on Mon, 02/09/2015 - 14:51

Hi everybody! I'm new in CFDEM and I'm trying to solve some issues that I have on my simulation. The setup it's quite simple, a square box with three small inlets and one outlet. The particles are inserted on the top of the box and y want to visualize how they are transported by the fluid.

Voidfraction considering overlap volume of particles in CFDEM

Submitted by NTT1508 on Tue, 01/27/2015 - 13:38

Hi all,

I am a new guy in CFDEM and currently interested in void fraction calculation and how it effect on fluid-particle interaction. I have looked at src/submodel for voidfraction calculation however not sure whether current solution considers overlap volume of particles or not? Could any one please clarify me this confusion? Additionally, I have tried using dividededvoidfractionmodel for several cases but it seems not be fully correct to my geometric calculation method. Do voidfractionmodels in CFDEM propose and accept any error or tolerance?

Thank very much,

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