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-   -   Meshing an airplane-why does it mesh the interior? (http://www.cfd-online.com/Forums/star-ccm/86916-meshing-airplane-why-does-mesh-interior.html)

sinpc15 April 6, 2011 06:10

Meshing an airplane-why does it mesh the interior?
 
Hi everyone,

Im trying to mesh an airplane. Until now, i have worked only with half of it and everything has worked fine. My symetry wall was stuck to the symetry plane section of the airplane.

But now i want to study the complete airplane, so I went to CATIA, I made a symetry of it and I tried to mesh it with exactly the same parameters (now the block surface that is around is NOT stuck to the airplane; obviously)

My problem is that it meshes ONLY the interior of the airplane and NOT the exterior. It has not holes because the same geometry worked perfectly before, and I dont now what to do.

I will apreciate any help

Regards

mahbub03 April 7, 2011 04:45

Which software you are using for mesh generation?

sinpc15 April 7, 2011 09:27

Im using the mesh tools in star ccm+

nomad April 7, 2011 14:00

Can we see some images? Cross-sections of the mesh preferably.

Was your symmetry plane at the origin (0,0,0)? Did you reflect one half to get the other half? If the symmetry plane wasn't at the center, then the reflection would leave a gap along the center line in which case it would mesh the interior. In this case you could repair the geometry by zipping down the center line.

Also, if you've left the symmetry wall in there, then it would mesh that. There shouldn't be any geometry inside the fuselage if you're trying to study external flow.

sinpc15 April 8, 2011 04:05

Thank you for your answers.

I cannot send you pictures since Im not allowed by my company, sorry.

The symetry was done reflecting one half and the symetry plane was at the center, I think there's no gap. I will check however.
I think star ccm+ believes that the fluid it has to mesh is the fluid in the interior of the airplane, and I dont know how to do it. I dont understand why with half of the airplane it meshed perfectly and now it doesnt. Maybe its because the symetry plane was part of the boundaries?

cfd_newbie April 8, 2011 05:37

Quote:

Originally Posted by sinpc15 (Post 302755)
Thank you for your answers.

I cannot send you pictures since Im not allowed by my company, sorry.

The symetry was done reflecting one half and the symetry plane was at the center, I think there's no gap. I will check however.
I think star ccm+ believes that the fluid it has to mesh is the fluid in the interior of the airplane, and I dont know how to do it. I dont understand why with half of the airplane it meshed perfectly and now it doesnt. Maybe its because the symetry plane was part of the boundaries?

Hi sinpc,
I have done this once before. What we did was we reflected the mesh itself (We used Hypermesh as our meshing tool) and simply deleted the symmetry container name (cells were there we only deleted the plane). Why are you going back again to CATIA, you can use you existing mesh only.


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