CFD Online Discussion Forums

CFD Online Discussion Forums (
-   ANSYS Meshing & Geometry (
-   -   [ICEM] combining mesh with geometry (

kasman_meng June 18, 2010 17:15

combining mesh with geometry
Hello to everyone!

What I want to do in ICEM is use a hexa mesh that I already have, delete part of it, and replace it with another tetra or prisma mesh that I will create. Do you think that this would be possible? Can anybody provide any hints on how to do this?


PSYMN June 19, 2010 21:44

Yup... totally possible... And not too difficult easier.

And there are lots of ways to do it. First some questions so I can narrow it down to the best way.

Are you adding mesh or geometry within the re meshed region? Does this additional geometry/mesh touch the walls? Can you provide a sketch or image so I can understand how things fit together?


kasman_meng June 20, 2010 11:14

Hello and thanks for your interest!

What I want to do for the time being is quite simple, I mean imagine having a 3D box, meshed, and wanting to change one if the sides of the box and replace it with another part of mesh. I already know that the replace side with the new one should have a common perimeter, but don't really understand what this really means. Should I do the new connection on the level of geometry(facets) and then mesh the new geometry or can this be done also with meshes? I'll try until tomorrow and provide a foto of what I have and what I want....

Thanks again!

kasman_meng June 21, 2010 06:38

2 Attachment(s)
So, here I attach the photos of what I want to do.... it's an Ahmed body, in a tunnel(which I have meshed but couldn't upload) and the other foto shows a duct, which I want to plug into the underbody and will go all the way through till the back part of the body. Hope I am explaining well my concept... I left a part of the underbody, extruded by 0.5mm in order to have a common perimeter of reference.... Would be grateful for some hints on how to proceed further... Thanks again!

PSYMN June 21, 2010 10:07

Hexa Tunnel
3 Attachment(s)
Sorry, I have read this a few times and don't understand what you have or what you want...

Is the tunnel Hexa meshed? Do you want to replace a block of the tunnel with a Tetra mesh of the Car? Yes, no problem.

You can find posts with a link to the 2008 tips and tricks ppt (I forget it right now)...

But here are some pics...

If you are doing something else, let me know and I can give other suggestions...


PSYMN June 21, 2010 10:09

Just hexa mesh the whole thing.
One other thought... This hybrid method makes sense for a complex geometry that you may not want to Hexa mesh, but for this particular example, it is pretty easy to Hexa mesh the whole thing.

If your study won't include much more complicated models, you should consider just hexa meshing the whole thing.

kasman_meng June 22, 2010 05:39

Although I managed to hexa mesh the plain geometry of the ahmed body, when I add this duct( imagine that it is a canal, inside the body of the car, beginning from the bottom and ending in the back.), I can't mesh it anymore( due to my restricted knowledge of using the program...)
That's the reason I am trying with tetra...
Do you think that if I mesh seperately the rectangular duct with hexa, there is a way to merge later the two meshes ?


PSYMN June 22, 2010 09:47

Oh, I get it now. The duct is inside the car...

Yes, if you hexa mesh the duct (separate blocking) and you add the splits for the duct opening to the other hexa model, you can merge the sub topologies.

I have a meeting now, but at my next break, I will upload a basic/rough ppt to illustrate how.


PSYMN June 22, 2010 09:56

Merge Topology
I could only find a presentation from 2005 (from ICEM CFD 5.1). They probably have newer ones on the customer portal, but I will post this for now.

The steps are still the same.


kasman_meng June 22, 2010 10:40

Hey! Thanks alot... I'll study the file and try it out..
Although what I have done till now is insert a totally new geometry in 'ICEM(body with the duct) and mesh it altogether in tetra.. did work!! But then crashed when I inserted also prisms.... Guess because I didn't smooth sufficiently.... But I'd rather have my whole model in hexa for greater accuracy.....

All times are GMT -4. The time now is 03:25.