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-   -   Lagrangian particles and ParaFoam (http://www.cfd-online.com/Forums/openfoam-solving/58389-lagrangian-particles-parafoam.html)

lucchini July 19, 2005 09:25

Hi all, I would like to post-
 
Hi all,
I would like to post-process my diesel-spray cases with paraFoam. I am able to see all the "eulerian" fields, but I don't know how to see the lagrangian particles and all the variable related to them.
Can anyone help me?
Thanks in advance.
Regards
Tommaso

mattijs July 19, 2005 10:40

Not possible with paraFoam as
 
Not possible with paraFoam as far as I can remember. Use foamToVTK instead.

Read the lagrangian data and 'Glyph' it.

dbxmcf November 3, 2008 00:28

Is there a way now to animate
 
Is there a way now to animate the particle (or droplets) movement with the results from the IcoLagrangianFoam? I have searched the wiki and found the following:
http://openfoamwiki.net/index.php/Main_FAQ#Postprocessing_of_Lagrangian_particle s
1. Run the foamToVTK post-processing utility. As with all OpenFOAM programs.
2. Read in your Eulerian data, if you wish
3. Read the Lagrangian data separately and 'Glyph' it. Glyphs are how Paraview represents point data. Usually, the sphere glyph is the most appropriate.

When use glyph, we only see the particles in a specific time frame, is there a way to animate it? Like what we do for the volScalarField or volVectorField? Thanks!

gschaider November 3, 2008 07:58

Hi Roy! The paraFoam that c
 
Hi Roy!

The paraFoam that comes with 1.5 has the ability to read lagrangian-data without converting it.

If you're stuck with 1.4.x try using paraview 3.x. It recognizes a series of .vtk-files as a time-series and these can be "played" as animations (don't know about the paraview 2.x-series). If you're reading in two series of the same length, then these get played in synchronicity

Bernhard

dbxmcf November 3, 2008 11:16

Thanks, Bernhard, do you know
 
Thanks, Bernhard, do you know if there is already such examples (write particle data and then use foamToVTK) available? or I should start write my own script?

gschaider November 3, 2008 14:35

Just run foamToVTK on your cas
 
Just run foamToVTK on your case. It will generate all the necessary data in a sub-directory named VTK in that case. The use "Open" in paraview

dbxmcf November 3, 2008 15:02

Thanks, I didn't notice that p
 
Thanks, I didn't notice that paraview 3.4 does not need to "Glyph" for every time frame but only needs to Glyph once for the lagrangian data.

foamWang June 3, 2010 20:47

Hi, all

The foamToVTK runs very well, but the eulerian and lagrangian field don't match in time.

LagrangianFoam always goes with integral time, eulerian goes with real time.

e.g. if my output time step is 0.1 s, 1st eulerian field is 0.1 s, but 1st lagrangian frame is at 1 s, i.e.the lagrangian field updates only when t=1, 2, 3 ..., eulerian updates at t=0.1 0.2 ... If the total number of frames are 100, eulerian field will finish showing up at t=10, (the time shows 10s in the toolbar) however, lagrangian field is still at t=1 s. afterwards, the lag field will update only to show all the frames. It seems lag field has no time infomation.

any idea to solve this?

Thanks.

Roro

Quote:

Originally Posted by gschaider (Post 183771)
Just run foamToVTK on your case. It will generate all the necessary data in a sub-directory named VTK in that case. The use "Open" in paraview


matejfor June 4, 2010 02:15

Hi,
it never happend to me, I have all the time progress I've computed with lagrang. fields. You may check the VTK directory foamToVTK created and have a look if you have a list of lagrangian data as well as eulerian. What version of paraview are you using? Get the latest 3.8 from http://www.paraview.org/paraview/res.../software.html - the precompiled version - and try it again.

good luck
matej

Prash April 4, 2011 13:50

Hey,

I have recently encountered same problem, did you find a solution to this problem of differnt time matching for Eulerian and Lagrangian? Please reply :)

Best Wishes
Prashant








Quote:

Originally Posted by foamWang (Post 261608)
Hi, all

The foamToVTK runs very well, but the eulerian and lagrangian field don't match in time.

LagrangianFoam always goes with integral time, eulerian goes with real time.

e.g. if my output time step is 0.1 s, 1st eulerian field is 0.1 s, but 1st lagrangian frame is at 1 s, i.e.the lagrangian field updates only when t=1, 2, 3 ..., eulerian updates at t=0.1 0.2 ... If the total number of frames are 100, eulerian field will finish showing up at t=10, (the time shows 10s in the toolbar) however, lagrangian field is still at t=1 s. afterwards, the lag field will update only to show all the frames. It seems lag field has no time infomation.

any idea to solve this?

Thanks.

Roro


foamWang April 4, 2011 14:46

Hi,

After updating to paraview version 3.8 or later, this problem is gone.

Bless,

Roro

Quote:

Originally Posted by Prash (Post 302178)
Hey,

I have recently encountered same problem, did you find a solution to this problem of differnt time matching for Eulerian and Lagrangian? Please reply :)

Best Wishes
Prashant


Prash April 4, 2011 15:04

Hey ,

I am using Paraview 3.8.1 , but its encountering the same problem. Do you have suggestions? While solving its solved for the Eulerian time step, but I do not why but while using foamToVTK and reading that to paraview, it runs for different time steps for Eulerian ( 0,0.01......0.1) and after that (1,....10) for lagrangian. I even tried renaming the VTK files, it still doesnt work.

Please suggest.

Best Wishes
Prashant




Quote:

Originally Posted by foamWang (Post 302185)
Hi,

After updating to paraview version 3.8 or later, this problem is gone.

Bless,

Roro



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