CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Running, Solving & CFD (http://www.cfd-online.com/Forums/openfoam-solving/)
-   -   particle tracking needs YOU! (http://www.cfd-online.com/Forums/openfoam-solving/120966-particle-tracking-needs-you.html)

sanjar July 18, 2013 05:50

particle tracking needs YOU!
 
Hey guys, i m happy that i found this forum for openfoam. i hope that i find some advice or even a somebody with good OF skills for around 15 minutes for my OF case.
shortly what it is about:
i want to create a particle tracking case with the euler langrage method.

For this i created two sub-cases;
one with the fluid and the other one with the particles.
the following describes what i did:

1) solved the fluid case with simpleFoam,

2) coupled it with the case of the particle with "mapFields ..(case-fluid)/(case-particle)

3) opened the particle case, solved it with icoUncoupledKinematicParcelFoam

4) foamToVTK

5) paraFoam

6) here is the problem: i do not see any particles. i clicked "next frame" as long as i could but there was no langragian field at all.. ;(

i wonder why it doesnt work.
the case with the fluid seems to be correct.

If there is somebody who did that already, just a particle tracking case, it would be fantastic to help me!

Thank you in advance!

Just answer here in this thread or a pm! ;)

Sanjar

Dommy July 18, 2013 17:07

Doing the same at the moment! Lets share because I have some serious issues with my case!

For your post processing read this http://openfoamwiki.net/index.php/Ma...gian_particles

A different way (which is more disk space saving) is to use Paraview right after reconstucting - or even before!

(Reconstruct) - Paraview - reconstucted case - turn on lagrangian/kinematiccloud - of course there are no particles at time step 0! -> hopefully see your parcels..

You may find this useful as well http://openfoamwiki.net/index.php/Tu..._based_methods

If this doesn't help - share your case - I will have a look!


Question back - have you looked into Dispersion models?

Best,
Thomas

sanjar July 20, 2013 05:31

1 Attachment(s)
hey thomas,

here are the cases. as i described i split them into two subcases.
i didnt pack the mesh-data in it, but it is in both cases included.

Best regards!

sanjar July 20, 2013 05:36

2 Attachment(s)
case with particles

sanjar July 20, 2013 05:43

1 Attachment(s)
0-file for particle

hope you guys can see what is (are) my mistake(s)

Dommy July 20, 2013 16:57

I cant see a real mistake - just some ideas.

You should refine your time step in the particle case. At the moment you are calculating the position of your particle cloud every second which might not be sufficient if your fluid flows with 5 m/s. I dont know the size of your mesh but if the particles reach 5 m/s they travel 5 meters before you track them again - try something much smaller.

Second idea: refine your writing interval - you are only able to see changes in the field every 10 seconds - with this flow speed that cant be sufficient ;)

How big is your mesh? Any chance to attach it? I started with Euler - Lagrange 2 months ago and I want to see as many cases as I can ;)

Best,
Thomas

mayank.dce2k7 September 4, 2013 13:16

Hi Sanjar,

I see you are working with icoUncoupledKinematicParcelFoam. Do you know how to give initial particle velocity equal to fluid velocity. My fluid velocity field at inlet varies with space(i.e parabolic)? I need the particle to follow same profile?

Regards,
Mayank


All times are GMT -4. The time now is 02:46.