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-   -   [GAMBIT] Problem in generation oval surface (http://www.cfd-online.com/Forums/ansys-meshing/101336-problem-generation-oval-surface.html)

wind.cfd May 1, 2012 15:02

Problem in generation oval surface
 
Hello,
I want to create the oval shape pipe. because it is connected to two other cylinder, I want to create the 2D geometry and then revolve them to generate 3D shape. My problem is that I dont know how to do that. I would really appreciated if someone let me know how is is possible?

Thanks alot

-mAx- May 2, 2012 02:54

can you post a sketch of what you want exactly

wind.cfd May 2, 2012 12:03

Quote:

Originally Posted by -mAx- (Post 358753)
can you post a sketch of what you want exactly

Tnx mAx for your attention,
I don't know how to attach my file to show you my model?!
Could you help me

wind.cfd May 2, 2012 12:42

Actually when I create the ellipse edge and want to sweep the edge, I gave the following error: the edge being swept has moved from its original location. Try changing the default GEOMETRY.VOLUME.SWEEP_PATH_ALIGNMENT to 1 or try aligning the path(edge/vector) to start from edge being swept.
ERROR: sweeping or revolving edge edge.3 failed

Do you know what should I do?

-mAx- May 3, 2012 01:09

http://www.cfd-online.com/Forums/faq...b3_attachments

wind.cfd May 4, 2012 19:09

3 Attachment(s)
p { margin-bottom: 0.08in; } Hi mAx,
I have attached the pics of my model, also I have written the process of the generation.
The process of generating this geometry


  1. create edge circle AB (which is the interface of oval and large cylinder)
  2. create face circle AB
  3. create oval face EF (which is the interface of oval and large cylinder)
  4. sweep oval face EF to generate volume
  5. delete oval volume to remain oval surface
  6. subtract oval face from circle
  7. sweep circle face AB to create volume
  8. create edge circle CD (which is the interface of oval and small cylinder)
  9. create face circle CD
  10. subtract oval surface which is connected to the above face
  11. sweep edge circle CD to create face


Actually, I do this process because I need to define the boundary layer same in attached pic.
Now I want to create three separate volumes (large cylinder, small cylinder, oval cylinder)
but when I do that I get the error regarding to open shell.
What do you think about the process I applied?
TNX

-mAx- May 14, 2012 01:45

3 Attachment(s)
I received your files.
You cannot mesh your ellipse volume, because auf highly skewed element on top and bottom caps.
Attachment 13104
I you delete your mesh, and enable shaded modus on, you will see something is wrong
Attachment 13105

Now you need to know that gambit is dimensionless, so try to create the ellipse (create cylinder) with r1=333, r2=3000 and height 2000. (you will be able to scale your model later in fluent)
Then you may try to create your size function. (on the picture, I splited the edge twice, for having an edge just at the curvature and I applied a fixed size function an this edge)
Attachment 13106

wind.cfd May 15, 2012 13:24

Quote:

Originally Posted by -mAx- (Post 360876)
I received your files.
You cannot mesh your ellipse volume, because auf highly skewed element on top and bottom caps.
Attachment 13104
I you delete your mesh, and enable shaded modus on, you will see something is wrong
Attachment 13105

Now you need to know that gambit is dimensionless, so try to create the ellipse (create cylinder) with r1=333, r2=3000 and height 2000. (you will be able to scale your model later in fluent)
Then you may try to create your size function. (on the picture, I splited the edge twice, for having an edge just at the curvature and I applied a fixed size function an this edge)
Attachment 13106

Thanks a lot for your consideration
Thats right my mesh has a high skewness at top and bottom, so I have to change the mesh.
Could you tell me how you split the edge and create the mesh on the top edge, I could not do that. If you tell me the steps I would really appreciated.

-mAx- May 16, 2012 00:30

edge>split edge with location
the edge will be splitted where you are cliking on.
Do the procedure twice for isolating and edge at the curvature.
Then create your size function with fixed option and select your edge as source


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