[Gmsh] Re : AW: Re : AW: Re : AW: Mesh STEP file
Zenker, Dr. Matthias
Matthias.Zenker at erbe-med.com
Wed Mar 30 13:32:36 CEST 2011
Hi Marc,
indeed I don't see physical entities in your mesh. You can check yourself, the format is easily human readable. Have a look at the gmsh reference manual, chapter 9.1: http://www.geuz.org/gmsh/doc/texinfo/gmsh.html#MSH-ASCII-file-format
I don't know what went wrong here.
I have never used dolfyn and cannot comment on the error you report.
So unfortunately, I cannot help you at the moment, but someone else on the list certainly will...
Good luck!
Matthias
P.S.: If you reply to the list (gmsh at geuz.org), you give the other participants a chance to help you...
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ERBE Elektromedizin GmbH
Dr.rer.nat. Matthias Zenker
Dipl. Phys.
Grundlagenentwicklung / Fundamental Development
Waldhoernlestrasse 17
72072 Tuebingen
Germany
Phone + 49 (0) 7071 755 - 226
Fax + 49 (0) 7071 755 - 5226
E-Mail: <mailto:Matthias.Zenker at erbe-med.com>
URL: http://www.ERBE-med.com <http://www.erbe-med.com/>
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________________________________
Von: Marc Secca [mailto:mksca220 at yahoo.fr]
Gesendet: Mittwoch, 30. März 2011 11:56
An: Zenker, Dr. Matthias
Betreff: Re : AW: Re : AW: Re : AW: [Gmsh] Mesh STEP file
There you go!
Thanks!
________________________________
De : "Zenker, Dr. Matthias" <Matthias.Zenker at erbe-med.com>
À : Marc Secca <mksca220 at yahoo.fr>
Envoyé le : Mer 30 mars 2011, 10h 33min 13s
Objet : AW: Re : AW: Re : AW: [Gmsh] Mesh STEP file
Hi Marc,
could you send me the e-Mail again with a compressed attachment (e.g. zip), our system seems not to like .msh files.
Matthias
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ERBE Elektromedizin GmbH
Dr.rer.nat. Matthias Zenker
Dipl. Phys.
Grundlagenentwicklung / Fundamental Development
Waldhoernlestrasse 17
72072 Tuebingen
Germany
Phone + 49 (0) 7071 755 - 226
Fax + 49 (0) 7071 755 - 5226
E-Mail: <mailto:Matthias.Zenker at erbe-med.com>
URL: http://www.ERBE-med.com <http://www.erbe-med.com/>
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________________________________
Von: Marc Secca [mailto:mksca220 at yahoo.fr]
Gesendet: Mittwoch, 30. März 2011 11:12
An: Zenker, Dr. Matthias
Betreff: Re : AW: Re : AW: [Gmsh] Mesh STEP file
Hi Matthias,
Thanks again for your help. I created the mesh as you advised:
1.
* Open Tools->Options->Mesh->General and set the Max element size to something like 10 ini your case.
* Open Tools->Options->Mesh->Advanced and select "Compute element sizes from curvature"
2. I saved the mesh with the option Save all (ignore Physical groups) unticked. I thus defined all the surfaces and volumes of the geometry as physical groups. There should be 4 in total (1 volume and 3 surface sets)
I have attached the resulting mesh file. This time, I didn't give the boundaries any names but left them as the numbers they were assigned. Can you tell me if you can see the physical groups in the mesh file and how to look for them?
Also, I don't know if you have used dolfyn CFD solver before but when I put the mesh through the preprocessor, I get several errors saying that:"Inconsistent data: Physical names ids overlap 1"
Any ideas what is going wrong?
Your help is very much appreciated. Thanks
Marc
________________________________
De : "Zenker, Dr. Matthias" <Matthias.Zenker at erbe-med.com>
À : Marc Secca <mksca220 at yahoo.fr>
Cc : gmsh at geuz.org
Envoyé le : Mer 30 mars 2011, 9h 00min 03s
Objet : AW: Re : AW: [Gmsh] Mesh STEP file
Hi Marc,
what you do seems resonable to me.
When you save the mesh, you have the choice to ignore physical groups, so everything is saved, or to save just the physical groups. In the latter case, you have to define every surface and volume as physical if you want to have it saved. As far as I see, the physical groups appear as numbers in the mesh. I have never tried to name them, so someone else has to help you here.
To make a finer mesh, you can do one or more of the following things:
* Assign a characteristic length to the points. There is a possibility to do this with the GUI, but I don't remember it right now. You can still do it in the geo file.
* Open Tools->Options->Mesh->General and set the Max element size to something like 10 ini your case.
* Open Tools->Options->Mesh->Advanced and select "Compute element sizes from curvature"
You can have a look at http://www.geuz.org/gmsh/screencasts/ where the GUI is demonstrated.
(@gmsh team: It would be nice to add in the reference manual how the described commands can be executed from the GUI.)
HTH,
Matthias
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ERBE Elektromedizin GmbH
Dr.rer.nat. Matthias Zenker
Dipl. Phys.
Grundlagenentwicklung / Fundamental Development
Waldhoernlestrasse 17
72072 Tuebingen
Germany
Phone + 49 (0) 7071 755 - 226
Fax + 49 (0) 7071 755 - 5226
E-Mail: <mailto:Matthias.Zenker at erbe-med.com>
URL: http://www.ERBE-med.com <http://www.erbe-med.com/>
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________________________________
Von: Marc Secca [mailto:mksca220 at yahoo.fr]
Gesendet: Dienstag, 29. März 2011 14:06
An: Zenker, Dr. Matthias
Betreff: Re : AW: [Gmsh] Mesh STEP file
Hi Matthias,
Thanks for the reply!
I'm using the dolfyn cfd solver and it requires to define physical groups in gmsh in order to specify boundary conditions. How can I define these physical groups for that particular case?
1. merge the step file into a .geo file
2. select geometry/physical groups/add/then the surfaces and volume as required
3. rename the physical groups ( inlet...etc)
4. mesh (2D first then 3D)/ optimize and save the .msh file.
Then when I try open the .msh file, my physical group names don't appear anywhere?
Can you tell me if i'm doing this right? Am I missing something?
Also If I select 3D when meshing, the mesh is really coarse. I then refine it but it doesn't converge and crashes as a result? Can you shed some light on this issue?
Thanks!
Marc
PS:I'm relatively new to Gmsh so please bare with me if I'm asking basic questions :-)
________________________________
De : "Zenker, Dr. Matthias" <Matthias.Zenker at erbe-med.com>
À : Marc Secca <mksca220 at yahoo.fr>; gmsh at geuz.org
Envoyé le : Mar 29 mars 2011, 12h 47min 21s
Objet : AW: [Gmsh] Mesh STEP file
Hi Marc,
when I mesh your geometry (without defining physical groups) and open it with Elmerfem (www.csc.fi/elmer), I can see all surfaces as boundaries. So they must be in the msh file. The problem may be the way your cfd software reads the msh file.
HTH,
Matthias
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ERBE Elektromedizin GmbH
Dr.rer.nat. Matthias Zenker
Dipl. Phys.
Grundlagenentwicklung / Fundamental Development
Waldhoernlestrasse 17
72072 Tuebingen
Germany
Phone + 49 (0) 7071 755 - 226
Fax + 49 (0) 7071 755 - 5226
E-Mail: <mailto:Matthias.Zenker at erbe-med.com>
URL: http://www.ERBE-med.com <http://www.erbe-med.com/>
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________________________________
Von: Marc Secca [mailto:mksca220 at yahoo.fr]
Gesendet: Dienstag, 29. März 2011 12:57
An: gmsh at geuz.org
Betreff: [Gmsh] Mesh STEP file
Hello!
I am trying to mesh the attached STEP file in gmsh 2.4.2 and define boundaries for a cfd solver. I can merge the file and select the relevant surfaces and volume as physical groups but after I mesh to geometry, I open the .msh file created and cannot see the boundaries I defined. I tried saving the geometry as a .geo file but surfaces are missing at the pipe intersections.
Is there a better way to do this? Can I repair the missing surfaces?
Thanks for any help you can provide.
Marc
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