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[mesh manipulation] a question about refineMesh

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Old   June 22, 2011, 10:09
Default a question about refineMesh
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liufang
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Hi everybody!
I' like using refineMesh to refime the mesh like below

but the result is like below

what should I do?
Thanks very much!
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Old   June 22, 2011, 21:46
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I have fund the answer, the refineMesh works well.The refined grids just like the first figure, but the paraview's display is not correct, The diagonal lines are of fictitious. I still do not know how to correct it.
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Old   June 22, 2011, 21:59
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Checking the "Use VTkPolyhedron", paraview will show the correct display.
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Old   June 28, 2011, 06:29
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stephane sanchi
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Hi,

Where is located the "Use VTkPolyhedron" in paraFoam ?

Regards,

Stephane.
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Old   June 28, 2011, 22:35
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Hi,
If you compile "PV3FoamReader Module" correctly, the paraview's "Object Inspector" looks like figure below ,you can check "use VTKPolyhedron".

but if you failed to compile "PV3FoamReader Module", paraview can still work, the "Object Inspector" looks like figure below ,you can not check "use VTKPolyhedron", the display is not correct, but the grids are ok.
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Old   September 5, 2011, 12:35
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Hi All,

OpenFOAM cannot use meshes with floating nodes, so no the, diagonals are not fictitious. Valid cell shapes recognized by OpenFOAM can be found here. Therefore, to correctly close the mesh shown in the first post, OpenFOAM will create triangles, which is consistent with the diagonals shown in paraview/paraFoam.

Kind regards,

Francois.
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Old   October 31, 2011, 11:22
Default how I can refine a specific region?
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giovanni silva
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Does anyone know how I can refine a specific region in a cavity for example?
Thanks!
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Old   January 20, 2012, 17:14
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Quote:
Originally Posted by fangliu View Post
Hi everybody!
I' like using refineMesh to refime the mesh like below

but the result is like below

what should I do?
Thanks very much!
I have the exact OPPOSITE problem ... refineMesh doesn't add the diagonal, so two faces are orthogonal to another single face, which creates problems

Is there a switch somewhere in the refineMeshDict that I haven't seen ???
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Old   April 8, 2016, 09:21
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Quote:
Originally Posted by Fransje View Post
OpenFOAM cannot use meshes with floating nodes, so no the, diagonals are not fictitious. Valid cell shapes recognized by OpenFOAM can be found here. Therefore, to correctly close the mesh shown in the first post, OpenFOAM will create triangles, which is consistent with the diagonals shown in paraview/paraFoam.
For whoever stumbles upon this, the above information seems to be incorrect (at least not anymore in OF-2.3.x). I created a small testcase, which consists of two vertically stacked blocks.
The lower block is then "refined" in 2 blocks. I visualised the result in paraview, once using VTKPolyhedra and once without, and further compared the visualisation with a plot in MATLAB, for which I directly exported the data from polyMesh/points and polyMesh/faces.

The result of the Matlab visualisation perfectly agrees with the VTKPolyhedral picture:
paraFoam+VTKPolyhedron.pngvisualisedBlockMesh.png

The paraFoam version not using VTKPolyhedra:
paraFoam-VTKPolyhedron.png

Also regarding the standard shapes linked, those are the ones recognised, but OF also supports arbitrary polyhedra (compare checkMesh output).

I also attach the testcase including my Matlab script for those interested.
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Last edited by Astrodan; April 8, 2016 at 09:47. Reason: Mixed up pictures
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