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-   -   High Aspect Ratio Cells in Paraview (http://www.cfd-online.com/Forums/openfoam/86960-high-aspect-ratio-cells-paraview.html)

jms April 7, 2011 06:48

High Aspect Ratio Cells in Paraview
 
Dear all,

Do any of you know how to check the cells with highest aspect ratio with Paraview? If there are cells with high aspect ratio checkMesh from OpenFOAM creates a file in "constant/sets" called "highAspectRatioCells". Is there any way to open this one in Paraview?

Thanks.

Regards,

José

elisabet April 7, 2011 10:31

Hi José,

Of course there is!

If you open your case with paraFoam, at the main page you see a list of options, among them:
-Update GUI
-Cache Mesh
-Extrapolate Walls
-Include Sets
-...
just click on 'Include Sets' and you'll see it.


If you prefer dealing with paraview, use the command:
foamToVTK -cellSet highAspectRatioCells
and load the file as usual.



enjoy!

elisabet

jms April 7, 2011 11:45

Thank you very much for your help!

What about this other thread I started in here?... do you know any thing?

Gràcies!

José

idefix May 13, 2013 03:52

Hello,

foamToVTK -cellSet highAspectRatioCells
is not working in my case.

I get the error massage:
--> FOAM FATAL ERROR:
Cannot find file "" in directory "polyMesh/sets" in times 0 down to constant

From function Time::findInstance(const fileName&, const word&, const IOobject::readOption, const word&)
in file db/Time/findInstance.C at line 140.

FOAM exiting

What is wrong? Can somebody help me?

Thanks a lot

wyldckat May 14, 2013 17:49

Greetings idefix,

Did you run checkMesh? Did it report any high aspect ratio cells?

You might also want to try the full diagnosis, by running:
Code:

checkMesh -allGeometry -allTopology
Best regards,
Bruno

idefix May 17, 2013 02:03

Hello Bruno,

thanks for your help.

checkMesh that´s that everything is ok

but checkMesh -allGeometry -allTopology

says:
Quote:


Cell determinant (wellposedness) : minimum: 0 average: 0
***Cells with small determinant found, number of cells: 4680
<<Writing 4680 under-determined cells to set underdeterminedCells
Concave cell check OK.

Failed 1 mesh checks.

End

It´s a test case and therefore the grid is very small. It has only 4680 cells - so every cell is "damaged".

But what does it exactly mean?

Thanks a lot
Regards
Idefix

idefix May 17, 2013 02:34

Hello again,

I just try a little and was wondering about the error massage because the grid looks nice to me.

By accident the error massage disappeared when I add more cells in the third dimension.
Before the grid has only 1 cell in the third dimension.

Why is this command (foamToVTK -cellSet highAspectRatioCells) not working for a 2d grid?

Thanks a lot
Idefix

wyldckat May 17, 2013 18:14

Hi Idefix,

You cannot get foamToVTK to process "highAspectRatioCells", simply because checkMesh did not find any cells with high aspect ratio.

What you could have done when you got the error for "under-determined cells", is use foamToVTK to give you a VTK file for the cellSet named "underdeterminedCells":
Code:

foamToVTK -cellSet underdeterminedCells
Only because you got this message:
Quote:

Code:

<<Writing 4680 under-determined cells to set underdeterminedCells

Best regards,
Bruno


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