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Meshing of very complicated part

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Old   April 6, 2008, 09:58
Default Meshing of very complicated part
  #1
Sanjay Jain
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I am trying to mesh volume of water contained by the rotor of Francis turbine(hydro turbine) which rotates. But the shape of the blade is so complicated that there are lots of curvatures in this volume.

I am trying to mesh it using Tet/Hybrid-Tgrid scheme but GAMBIT shows message that "Initialization failed; perturb boundary nodes and try again".

How to solve this problem?

Please....Please help me?

Sanjay Jain
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Old   April 6, 2008, 13:49
Default Re: Meshing of very complicated part
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BastiL
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Do you want to put boundary layers on this complicated geometry? In general I would propose to do surface meshing in Gambit and export to TGrid for volume meshing. For Tet/Hybrid meshes expecially with BL and complex geomtries TGrid is prefered.

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Old   April 6, 2008, 14:34
Default Re: Meshing of very complicated part
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Sanjay Jain
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Thanks for your suggestions.

I am not going to put the boundary layer. I don't have exposure to TGrid. If I am not wrong I believe that, in TGrid we can do only volume meshing. So I need to do the surface meshing in GAMBIT. In that case also, GAMBIT shows lots of elements having skewness more than 0.97 and surface meshing is also not taking place.

I don't know how to came out of it? Please let me know as early as possible.

Thanks in advance.

Sanjay

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Old   April 7, 2008, 02:11
Default Re: Meshing of very complicated part
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mAx
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inspect the cause of your 0.97 skewness. (short edges, small angles, etc...). Once you identified it, adapt your geometry (split/merge etc...)
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Old   April 7, 2008, 06:15
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Aris
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The problem is due to high skweeness. You should have better surface mesh. An other thing is that you can "play" with Gambit default constants. For example you can increase the upper limit of the acceptable angle e.t.c.
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Old   April 7, 2008, 12:40
Default Re: Meshing of very complicated part
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Sanjay Jain
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Thanks for your suggestions. I will try these options.

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Old   April 5, 2009, 17:00
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bilquise
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Hello,
I am student trying to simulate a heat transfer through fins. When I am trying to mesh my continuum I have the same error of Initialiation failed,perturb boundary nodes and try again .This is usuualy caused by face meshescheck the skewness of your face mesh and make sure the face mesh size is not too large.
I tried to divide my geometry into smaller components and mesh it and even after that I get the same error..I am a begineer with Gambit and Fluent can smebody help me fix my problem
Thank you
Bilquise
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Old   April 6, 2009, 00:47
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Maxime Perelli
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I fyou have divided your domain, you should have localized where it occures (in which volume)
Then check if you don't have short edges, small angle etc...
You can also check the surface mesh quality and observe where is the worse cell's quality, it will help to know where is the problem
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Old   April 6, 2009, 19:42
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bilquise
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I do have some small edges laces of small eges and small angels,However the problem is I do not know how to deal with them.
I have tried cleaning my geomtery but I still get the same error
Please advice
Thank you
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Old   April 7, 2009, 00:21
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Maxime Perelli
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*merge edges
*merge faces
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