CFDEM®coupling - User Forum

Dear all,
I am a new comer in CFDEM, recently I just used CFDEM to simulate the suspended sediment transport, but I always get some particles' velocity larger than the fluid velocity, it that because the time step of DEM side, or I use a wrong model? And in most of time, how can we decide the time step of the DEM side?
Thank you for your help!
Best Wishes!

my couplingProperties is:

ModelType B; // A or B

couplingInterval 10;//CFD timestep 0.0001, DEM timestep 0.00001

voidFractionModel divided;//centre;//bigParticle;//

Dear all,

Hi everybody,

I do not know the specific function of rho in 0 directory running solverpiso. Does it parameter affect the fluid properties? According to openfoam fluid properties the only feature which define a fluid is kinematic viscosity (nu) nu=mu/rho.

Best regards,

Carlos

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?

Hello,

I have gotten confused trying to define the presure (p) on CFD folders. I have just read about the ratio between pressure and density but the data in cfdemsolver express a 0 value. Does anyone know about this issue?

Best regards,

David

Hi CFDEM members,

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)

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.

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.

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/