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-   -   Meshing problems in GAMBIT (http://www.cfd-online.com/Forums/ansys-meshing/71575-meshing-problems-gambit.html)

blin January 8, 2010 03:04

Meshing problems in GAMBIT
 
Hello everyone,

I'm new to CFD so please bare with me here. :)
I am working on a school project that involves CFD of a car in a virtual wind tunnel. I've modeled the shape of the car myself and did not include many details. I am doing the mesh in GAMBIT, and I'm following the same procedures as this tutorial:

http://www.ent.ohiou.edu/~juwt/HTMLS...guide/tg05.htm

My 2D mesh is fairly good (i think?). The skew equisize and equiangle skew of the 2D elements are less than 0.6.
I am using a mesh size of 20 mm (the car is to scale). And I'm using a virtual wind tunnel box size of 5000x5000x15000. I've followed all the same procedures to create the 3D mesh as indicated in the tutorial but with different mesh size numbers since my model is a lot larger than the one in the tutorial.
I've also created a line mesh of interval size 240 around the "wind tunnel box".
However, whenever I try to create the 3D mesh, I get this error:

Initialization failed; perturb bounday nodes and try again
Initialization failed to mesh 44 nodes
Error: TG_Mesh_Domain failed with error code 1
Error: Tetrahedral_meshing has failed for volume v_volume 1
This is usually caused by problems in the face meshes.
Check the skewness of your face meshes and make sure the face mesh sizes are not too large in areas of small gaps.

Any help? I've been stuck on this for days and I would like to complete this project on time :(

Thanks in advance.

-mAx- January 11, 2010 02:29

this is a size problem.
give the same parameters as in the tutorial.
Then if you want to do you own mesh, I would suggest you to use Size Function on car surfaces. (no need to mesh surfaces and edges)

blin January 11, 2010 11:27

Thank you max for your recommendation.
Could you kindly explain in brief detail where I can find the size function, and how to implement it? Sorry but I'm really new to this and have not used that function before.

Thanks very much

blin January 11, 2010 12:19

Actually, I found this very useful link:
http://www.ent.ohiou.edu/~juwt/HTMLS...ide/mg0502.htm

blin January 11, 2010 12:55

This worked!!!
thank you very much :D


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