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-   ANSYS Meshing & Geometry (https://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [ICEM] Meshing problem in Formula one (https://www.cfd-online.com/Forums/ansys-meshing/110911-meshing-problem-formula-one.html)

cfd seeker January 14, 2013 11:22
Quote:
He has to mesh all the surfaces... he cannot skipe some. because later he will have to apply delaunay... octree mesh will not work or it will change his actual surface mesh.
we can mesh some surfaces with patch dependent and still use octree. Simon has told me this in some other thraed. Mesh your desired surafces with patch dependent and skip others which will be meshed by octree and those alraedy meshed surafces will still have patch dependent mesh in the final octree mesh

Far January 14, 2013 11:25
progress upto now. Surface mesh of full wheel completed. Danualy mesh generated.

Facing problems in prism generation (tried both pre and post inflation) . Always get the pyramids. Any idea how to avoid pyramids? (Already tried prism quality to 0.0001)

Should I use Tgrid now?


http://imageshack.us/a/img515/8859/shellmeshing8.png

http://imageshack.us/a/img842/4168/picsurface.jpg
http://imageshack.us/a/img577/7640/shellmeshing9.png
http://imageshack.us/a/img694/817/picsurface003.jpg
http://imageshack.us/a/img5/6307/picsurface005.jpg
http://imageshack.us/a/img51/6339/picsurface004.jpg

Far January 14, 2013 11:27
Quote:
Originally Posted by cfd seeker (Post 401775)
we can mesh some surfaces with patch dependent and still use octree. Simon has told me this in some other thraed. Mesh your desired surafces with patch dependent and skip others which will be meshed by octree and those alraedy meshed surafces will still have patch dependent mesh in the final octree mesh
Not possible. It is against the octree way of working.

However you can first use the octree and delete the volume mesh. Delete the unwanted surface mesh and recreate surface mesh with pd method and fill the volume with denauly.

cfd seeker January 14, 2013 11:29
Quote:
Hey I thought you are girl. Thats why I talked to you in late hours. And those sweet nothings were due to fact that somebody was home

But I wasted my time, as you are in crotia and turned to be boy instead hehehe\
Hey what's going on in this serious thread :)

Far and scipy....tell me seriously who is boy and who is girl among you people :D

Far January 14, 2013 11:33
Quote:
Originally Posted by cfd seeker (Post 401778)
Hey what's going on in this serious thread :)

Far and scipy....tell me seriously who is boy and who is girl among you people :D
What do you think? :mad: Moreover ICEM and gril both are difficult to handle. So I face one at a time :D

Any input for the prism mesh generation in ICEM?

cfd seeker January 14, 2013 11:41
Quote:
Originally Posted by Far (Post 401777)
Not possible. It is against the octree way of working.

However you can first use the octree and delete the volume mesh. Delete the unwanted surface mesh and recreate surface mesh with pd method and fill the volume with denauly.
Quote:
Not possible. It is against the octree way of working
http://www.cfd-online.com/Forums/ans...e-problem.html
Read post # 16(By Simon)
This is what I got from it but I can be wrong in my understanding

cfd seeker January 14, 2013 11:48
Quote:
Originally Posted by Far (Post 401779)
What do you think? :mad: Moreover ICEM and gril both are difficult to handle. So I face one at a time :D

Any input for the prism mesh generation in ICEM?
Quote:
Any input for the prism mesh generation in ICEM?
where are pyramids forming? I am sure they must be b/w the thin legs on the tyre. is it so?

cfd seeker January 14, 2013 11:49
Quote:
Any input for the prism mesh generation in ICEM?
where are pyramids forming? I am sure they must be b/w the thin legs on the tyre. is it so?

Far January 14, 2013 11:50
Quote:
Octree tetra uses the patch independent method... In fact, Octree tetra starts with the volume mesh (it is a top down method) and then figures out the surface mesh from there.

When you start with a patch conforming method, it actually generates the patch independent mesh as part of its process and then dumps it to make the octree volume mesh conformal with the surface mesh. This really combines the worst of both worlds, like having German Police and French Mechanics, instead of the other way around. There isn't really much good reason to do all the work required to get a good patch conforming surface mesh if you are going to fill it with Octree... The one good exception is when you have just a few patch conforming surfaces (perhaps coming from an adjacent model) that you want the octree to align with. Octree would then create all the other surface mesh that you need...

But in the end, I might still delete the octree mesh, smooth the surface mesh (alternating rounds of laplace and regular smoothing, ending with regular smoothing) and regenerate the volume mesh with a Delaunay Fill (with the TGlib and AF options).

In your case, patch conforming mesh on the difficult thin surfaces may be easier than octree (PI surface mesh) and then you can fill with delaunay.

If you have trouble with other surfaces in the model, just skip them with PI, and use Octree to capture them...
Are you referring to this? But I I dont understand the last paragraph. PI and octree are different?

cfd seeker January 14, 2013 12:03
Quote:
Originally Posted by Far (Post 401786)
Are you referring to this? But I I dont understand the last paragraph. PI and octree are different?
Yes I am refering to this post

Quote:
But I I dont understand the last paragraph. PI and octree are different?
Like I said before this is what I got from this paragraph....we can mesh some surfaces with patch dependent and still use octree. Simon has told me this in some other thraed. Mesh your desired surafces with patch dependent and skip others which will be meshed by octree and those alraedy meshed surafces will still have patch dependent mesh in the final octree mesh

diamondx January 14, 2013 12:18
FAR you remember the geometry i told you about

https://dl.dropbox.com/u/35161486/problem_ali.tin

specially this tubes, can you apply surface meshing on them :

https://dl.dropbox.com/u/35161486/tube.png

Far January 14, 2013 12:29
I will try...

diamondx January 14, 2013 12:43
sorry for bringing this up while you are busy with the car

Far January 14, 2013 14:16
Prisms grown succesfully in Tgrid along with volume mesh :)

http://img854.imageshack.us/img854/1219/prismtgrid.png

http://imageshack.us/a/img96/3241/46720903.png

http://imageshack.us/a/img12/7565/41588305.png

http://img836.imageshack.us/img836/4094/25595192.png

Far January 14, 2013 14:34
Quote:
Originally Posted by scipy (Post 401750)

If you weren't such a girl and reared your ugly head on GTalk/Skype here and there, I could've helped you with this already. :p

xoxo turbofar ;)
Hey scipy. Thanks for offer :rolleyes:

Far January 15, 2013 02:42
Here is problem I am facing in ICEM when I generate the prisms. Any solution to avoid the pyramids and get good looking, well grown, perpendicular prisms.
http://imageshack.us/a/img507/7892/p...ramidsicem.jpg
http://imageshack.us/a/img203/1797/p...amidsicem2.jpg
http://imageshack.us/a/img197/3763/prismicem.jpg


Also surface mesh is changed (quality go down) when volume mesh is generated
http://imageshack.us/a/img198/1320/p...badmeshons.jpg



Here is the mesh when I generated the prisms+tet+hexcore in Tgrid. Looks good.
http://imageshack.us/a/img233/1286/w...hexcoretgr.jpg
http://imageshack.us/a/img259/1286/w...hexcoretgr.jpg

cfd seeker January 15, 2013 02:50
Strange I thought pryramids to form b/w the thin gaps in the rim region of tire....any how is there a large difference in size on adjacent surfaces where the prisms have low quality?
The quality is all good in T-grid or there are also problems in T-grid?

Far January 15, 2013 02:56
Quote:
Originally Posted by cfd seeker (Post 401889)
Strange I thought pryramids to form b/w the thin gaps in the rim region of tire....any how is there a large difference in size on adjacent surfaces where the prisms have low quality?
The quality is all good in T-grid or there are also problems in T-grid?
At the moment I am attaching boundary layer (aka inflation) not inside the wheel. Only on the outer surface of the wheel.

Size in the original surface mesh is almost equal on the wheel and road and there is no jump in size at all. Almost of same size. This happens on the both sides of the prism region, while in the T-grid prisms are grown vertically and smoothly.

Quality is awesome in T-grid.

I know there is method to get the good prisms in ICEM as well, but I dont know what options to choose.

diamondx January 15, 2013 09:13
Quote:
Here is problem I am facing in ICEM when I generate the prisms. Any solution to avoid the pyramids and get good looking, well grown, perpendicular prisms.
i often get the same prism generation, did you try generating ONE big layer of prism instead, and dividing it ?

Far January 15, 2013 09:15
No. How to do this?


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