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Write the cell area of a patch

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Old   January 28, 2011, 05:11
Default Write the cell area of a patch
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Andrea Ferrari
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Hi all,

I am using the sample Dictionary to get the value of the color function alpha1 (using interFoam) on a particular patch (wall for my problem). Is possible to let OF prints not only the value of the color function but also the area of the surface (in m^2) for each cell on the patch wall??

I did not need the area of all cells but only those that are on the patch wall..

Thanks

Andrea
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Old   January 28, 2011, 05:30
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Niklas Nordin
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const scalarField& Ap = mesh.magSf().boundaryField()[i];

scalar patchArea = sum(Ap);
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Old   January 28, 2011, 05:41
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Andrea Ferrari
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Thanks for the quick response niklas. Sorry but i'm very new user on OF...where i have to put those line? and how can I specify the patch (wall for my problem) on which I want to calculate the area?

thanks

andrea
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Old   July 21, 2011, 10:46
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Dear All,

I would like to know if there is a C++ script (also a piece of code, or the post of the needed code lines would be appreciated) that can allow me to store in a file the coordinates of cell centres along with the areas of each cells, for every patch (or the one user specified) of my mesh. In fact, I need these informations for post processing purposes.

I thank You in advance.

Yours Sincerely.

Claudio
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Old   July 21, 2011, 11:31
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Hi Claudio,
For the cell centres i guess that you can simply use writeCellCentres
(under OpenFOAM/OpenFOAM-1.7.1/applications/utilities/postProcessing/miscellaneous/writeCellCentres). You will get the coordinates of the centers of all the mesh cells, including cells close to the boundary.

Then, if "areas of each cells, for every patch" means areas of each FACES that belong to a patch, take a look here (post #21)
write cell volumes

Hope this help

best
andrea
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Old   July 27, 2011, 08:29
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Thank You Andrea. It was just what I needed.

I have another question for you.

I would like to split cyclic patches in OF 1.7.1, in order to have two patches, namely patch_half0 and patch_half1, like can be done in OF 2.0.0.
Is there an utility to do so, in Openfoam 1.7.1?

As a matter of fact, when I try to calculate mass flow rate trough a cyclic patch in OF 1.7.1, the command "patchIntegrate phi cyclic_patch" returns me a near 0 value, whereas the same command given in OF 2.0.0 ("patchIntegrate phi cyclic_patch_half0") returns me a non zero (and correct) value.

Thank You in advance.

Claudio
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