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-   -   Import patch dependent 2d mesh into CFX (http://www.cfd-online.com/Forums/ansys-meshing/89927-import-patch-dependent-2d-mesh-into-cfx.html)

jose antonio June 26, 2011 08:35

Import patch dependent 2d mesh into CFX
 
Hello, could anybody help me with that? I am trying to import a mesh of a multielement airfoil into CFX but when I import the file I cannot apply the boundary conditions on the farfield. How do I have to extrude the mesh and import the file? Thank you in advance

PSYMN June 28, 2011 13:26

Part Names become BOCOS...
 
In ICEM CFD, Part names applied to the geometry are transferred to the mesh when it is generated. Boundary conditions can then be applied to these parts...

In 2D, this means you must be careful of the perimeter curve parts...

In other words, put the curves in INLET, OUTLET, FARFIELD, etc. so the mesh will be in these parts...

You can extrude these line element boundaries into boundary shells or you can just output a 2D Fluent MSH file and CFX will extrude it for you on input...

Best regards,

Simon

PSYMN June 28, 2011 13:28

Just in case...

If you are using ANSYS Meshing (Workbench) instead of ICEM CFD...

You will actually have to extrude your geometry some small thickness... And "Named Selections" become boundary conditions...

Hgyn August 5, 2011 07:58

Hello,

I have a similar Problem with exporting a mesh from ICEM CFD to Fluent.
If I use "patch dependant", the boundaries will not be delivered and if I use patch independant the mesh walks over a small gap which it should not do.

Thanks for your help.

PSYMN August 5, 2011 09:39

Sorry HGYN, No idea what you are talking about. Both ways should work no problem... Maybe you can post a pic or something to clarify.

With Patch dependent, it should mesh the boundaries first (it is a bottom up mesher). If you don't delete those, they should be available for export.

For Patch independent, it walks over details when the local mesh size is too high to capture the detail.

Hgyn August 9, 2011 08:08

Hello PSYMN,
as you see below the coarse patch independent mesh "walks" over the small gap, but if the mesh is fine enough it recognize the gap. The patch dependent version works fine, but I really have problems with the boundaries in FLUENT.




http://img96.imageshack.us/img96/796...ndependent.pnghttp://img89.imageshack.us/img89/348...dependent1.pnghttp://img217.imageshack.us/img217/3...edependent.png

PSYMN August 9, 2011 12:27

Sorry, I still don't understand the problem. Is one of these images (probably the first) the problem?

If you don't like the way it is jumping to the "wrong" point or curve when it meshes, you can just delete those curves or points before meshing and it will jump to the right ones. You don't need to merge surfaces or repair anything, just delete the entities and the mesher will ignore them.

Hgyn August 10, 2011 09:57

Hello,
so I have a model as it's shown down below,
BROWN=OUTLET, BLUE=INLET, GREEN=WALL, YELLOW=MEMBRANE.
the membrane is 10⁻⁵ mm thick and shall be deformed by increasing pressure. At the beginning I want to use a coarse mesh, but the coarse patch independent mesh walks over the membrane and with the patch dependent I have no boundaries in FLUENT.

Thanks for helping


http://img823.imageshack.us/img823/7042/membrane1.png


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