Fluid Simulation

Hi Daniela,
 Feng Chen did YADE-Open Foam coupling.

Reference:
Chen, Feng, "Coupled Flow Discrete Element Method Application in Granular Porous Media using Open Source Codes. " PhD diss.,
University of Tennessee, 2009.
http://trace.tennessee.edu/utk_graddiss/21

Regards,
Nurul Islam

.......................................................
Mohammad Nurul  Islam
Post Graduate Student
B:20, R:124, SEIT
UNSW@ADFA, Canberra, ACT 2600, Australia
Mobile: 0403468709
......................................................
Assistant Professor
Department of Civil Engineering
RUET, Rajshahi-6204, Bangladesh

________________________________
From: Daniela <email address hidden>
To: <email address hidden>
Sent: Wednesday, 20 July 2011 5:16 PM
Subject: [Yade-users] [Question #165417]: Fluid Simulation

New question #165417 on Yade:
https://answers.launchpad.net/yade/+question/165417

Hi,

I would like to know if it is already possible to simulate fluids in Yade? If yes, what is the method used?
Or is it already possible to run simulations using the coupling between Yade and OpenFoam?

Thanks in advance, Daniela.

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Hi!

and is this coupling in yade implemented? I mean, how could I then use it?

Besides that, is this parallelized? I saw in the work from Chen that till end of this dissertation the coupling could not run parallel.

Thanks again for the answer.
Daniela

Hi Daniela,

I am also interested in such a coupling (alternative for PFC-CCFD coupling).

I found this page:

http://sites.google.com/site/fchen3/home/yade-openfoam-src

For parallelized implementation you will have to wait or program it by yourself ...

Regards,

Christian

Hi Christian,

and is this a good coupling or are there limitations for using that?

Regards and thanks
Daniela

I have no experience with OpenFOAM and also not with the coupling to YADE.

Till now I used PFC-CCFD coupling and there are several limitations.

The main problem with a so-called continuum-discrete model is the dimensions of the fluid cells. Inside each cell there should be at least 10-20 DEM-particles. If you use less particles, the calculation gets instable. Also (as Chen mentioned) the calculation is quite slow for high numbers of particles.

Right now I experiment with a DEM-SPH coupling, but there are other problems with the numerical implementation (e.g. free surface with surface tension, high numbers of SPH particles for accurate solutions and so on).

Christian

Hi, Daniela:

I have initiated an ESyS-OpenFOAM coupling project since the beginning of this year, due to personal schedule it was not actively developed since March, recently I got quite a lot personal emails regarding this topic and code.

Although currently I am still facing some convergence and numerical instabilities, I am planning to release it pretty soon, I have created a project called ESyS-FOAM and will soon release the code.

Verification is a difficult thing and might need more people to join this work, also discuss the road map.

YADE-OpenFOAM coupling probably can be re-wrote in a similar way, once I upload the files, you are very welcome to use, test and contribute this, as far as I know, OpenFOAM 2.0 has already contained a DEM part, but I do not know much about it.

Feng

Hi Christian,
Do you know published references about this limitation to 10-20
particles per cell minimum? I heard that many times but couldn't find
anything precise (Feng Chen maybe?).

FYI, coupling with lattice Boltzman method has been implemented in Yade
by Franck Lomine and Luc Sibille, but it is not released yet. We
(Emanuele Catalano PhD) are also developping a coupling with Pore
Network/Finite Volumes, but it is still in development.

Bruno

Hi, Bruno:

That reference is from PFC2D's (v3.1) manual "Fixed coarse-grid fluid scheme in PFC2D", I remember it is in the second example of fluidized bed.

I have not done in-depth research about this, but my experience is your dn/dt and d(rho*n)/dt (n is the porosity, rho is fluid density) must be small (but don't know how small it should be) compared to other terms, or your solution for N-S equation will soon fail, if omit your porosity derivative in your N-S equation, everything will be happy...

feng

> Besides that, is this parallelized? I saw in the work from Chen that
> till end of this dissertation the coupling could not run parallel.

I am not familiar with CFD at all. But just a note.
Yade is more-less good parallelized with OpenMP.
So if this CFD-module will be added as an engine, for example, it will
not be a big problem
to parallelize it by the same way, I believe.

Anton

My 2 cents:

There are 3 things to parallel in this coupled problem:

1. Parallel in DEM itself (discrete particle domain decomposition, OpenMP, MPI etc)
2. Parallel in CFD (similar to above, continuum domain decomposition, OpenFOAM is mature on this)
3. Parallel in DEM-CFD (we are working on this, almost done)

Feng

> Hi Christian,
> Do you know published references about this limitation to 10-20
> particles per cell minimum? I heard that many times but couldn't find
> anything precise (Feng Chen maybe?).

PFC3D - CCFD Add-On manual (2008) page 2-9 (practical considerations):

"This coupling methodology is designed to describe the average coupling forces occuring within one fluid element. Flow around the particles is not explicitly represented, as the local porosity is assumed to be evenly distributed within one element. For good results, several particles should fit inside one CFD element:

dx/(2*r) > 5 [eq. 2.19]"

dx - fluid element length
r - particle radius

My personal experience with this code is to use better 50 to 100 particles (then 10-20) within each fluid element. I also only use so-called one-way-coupling. That means that only the fluid acts on the particles. I tried to use with full coupling, but after a few steps my model always explodes ... :o

Christian.

Thank you Christian. These comments are very instructive for us (we are
doing 2-ways coupling with Emanuele, with a very different kind of model).
The only problem is it is still very qualitative (no precise value of
what is "enough" particles).
Would you mind publishing a paper that we could cite, analyzing
stabillity conditions more precisely? ;-)

Maybe you find something about stability conditions of DEM-CFD coupling in this book:

http://onlinelibrary.wiley.com/doi/10.1002/0470020180.fmatter/summary

Hi Feng Chen?

How can I start the Yade Mechanical loop? How can I put FluidDragForceEngine in the simulation file on the yade in the CFD-DEM coupling?