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-   -   [ICEM] ICEM repair geometry issues (https://www.cfd-online.com/Forums/ansys-meshing/96362-icem-repair-geometry-issues.html)

robboflea January 20, 2012 08:16

ICEM repair geometry issues
 
2 Attachment(s)
Dear all,

I'm having troubles with repairing a IGES geometry imported in ICEM.

The first thing I don't understand is that, as far as I know, when I do "build topology" after the import I should select a tolerance smaller than the smallest mesh size I have. Since my aim is to go to really low y+ values my smallest cell size is around 10e-6 m. By selecting such a small tolerance almost all edges result unconnected. Of course by increasing the tolerance everything goes in the right place (see attached image) but I don't know if selecting the higher tolerance is right. And if not how could I then join the edges that are disconnected?

At the moment I proceeded with the topology created with the higher tolerance. Checking the surfaces I noticed that there are some holes in the connection of some surfaces. I deleted the surfaces and re-created them again using ICEM but still I get holes and other imperfections that are clearly visible in the attachment and are causing troubles in the mesh (penetrating and overlapping elements and volume orientation). All the problematic elements are on the blade surface, on the first layer of elements which is really thin as I told before.

I hope that someone could give me a hint on how to solve this problem.
Am I proceeding in the right way? Is there any step that I'm missing?
Thanks a lot.

Rob

Far January 20, 2012 11:14

Is this a NGV of High pressure turbine? Is this cascade or rotating geometry?

robboflea January 20, 2012 11:24

Is an NGV. It's a stationary model, coming from a linear cascade with a convergent meridional channel.

Far January 20, 2012 12:02

Extended NGV on both sides so that It crosses the wall on upper and lower side. then make the hub and casing planes without any gap for the blade and then make the periodic, inlet and outlet boundary and place material inside. I hope this will solve your problem.

robboflea January 20, 2012 12:14

Thanks Far, this sounds like another possible solution to my problem.
However I solved it by increasing the triangulation tolerance of the model. The creation of the surface from the edges runs smooth and without leaving any holes in the geometry.


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