CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS Meshing & Geometry (http://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [ICEM] not completing mesh of the surface (http://www.cfd-online.com/Forums/ansys-meshing/98730-not-completing-mesh-surface.html)

m5edr March 17, 2012 11:41

not completing mesh of the surface
 
2 Attachment(s)
This is a turbine blade
After many trials , the mesh of the surface is not cover the whole bade (specially along the trailing edge !!)


iam used various mesh types in Icem and played with mesh sizes but not able to solve this problem

Any help pls

rikio March 17, 2012 21:16

You need to adjust the Edge Criterion under Volume Meshing Parameters. It determines to what extent a tetra is cut to represent geometry. The entered value is a factor of the tetra edge. After subdivision, if a tetra edge intersects an entity (surface), the tetra will be cut if the subdivision of the edge from the intersection is less than the prescribed value.

Looking into this thread at Help at Mesh-Global Mesh Setup-Volume Meshing Parameters-Tetra/Mixed-Robust(Octree)

PSYMN March 19, 2012 12:07

Or turn on "thin cuts"

You may also need to reduce your mesh size.

This is a "behavior" associated with Octree mesh.

Another option would be to use another method (such as Patch Conforming Surface Mesh)...

m5edr March 19, 2012 12:45

Yes, i discovered that 1 day ago >>>> thin cut solve the problem

thanks

andrearudenick March 21, 2012 10:52

When you say "turn on thin cuts", do you mean to turn on the function "Define thin cuts" of the Volume Meshing Parameters section? or is there another ICEM function applied to shell meshing instead of volumen meshing? Because at the beginning you were talking about a surface mesh, and I'm having the same problem.

Thanks!

m5edr March 21, 2012 11:04

Quote:

Originally Posted by andrearudenick (Post 350684)
When you say "turn on thin cuts", do you mean to turn on the function "Define thin cuts" of the Volume Meshing Parameters section? or is there another ICEM function applied to shell meshing instead of volumen meshing? Because at the beginning you were talking about a surface mesh, and I'm having the same problem.

Thanks!


I mean "Define thin cuts" of the Volume Meshing Parameters section"
but first you should create two parts (of thin cut) at CREATE PART

PSYMN March 21, 2012 11:12

Right, Define Thin Cuts affects how the surface mesh is produced with the "patch independent (Octree)" meshing approach.

It is essentially an algorithm that says "if a surface element has a node on part A, then it should not have a node on Part B." Therefore you need to make sure that the two sides are in different parts. Also, if the two sides meet at a common curve, the curve must be in a 3rd part (separate from the two sides) or it will be impossible for the algorithm to succeed and it will fail out with a message.

Best regards,

Simon

m5edr March 21, 2012 11:20

hi simon

iam very sorry for this overlap (I'm feel it awkward :o)
I posted a problem in ICEM
could you show it :o :o
http://www.cfd-online.com/Forums/ans...-periodic.html

sorry again

PSYMN March 21, 2012 11:36

@m5edr...

Yes, I don't have time to read all the threads these days and I am missing more than I hit (I appreciate others on CFD-Online who can also help out).

If you want me to notice a thread, please don't pollute an unrelated thread. I would rather you just send me a private message with a link to the thread...

Best regards,

Simon

Ananthakrishnan April 24, 2012 18:30

Hi,
I had this problem and "define thin cut" did help. Now i have a different problem which is i am unable to create prism elements on the airfoil surfaces (these are the surface with which i have defined my "thin cut"). Is there anything i am missing??

m5edr April 24, 2012 18:37

Quote:

Originally Posted by Ananthakrishnan (Post 356750)
Hi,
I had this problem and "define thin cut" did help. Now i have a different problem which is i am unable to create prism elements on the airfoil surfaces (these are the surface with which i have defined my "thin cut"). Is there anything i am missing??

check
1- if you checked "create prism layers" in Compute mesh window
2- if you checked "prism" in Part mesh setup window

Ananthakrishnan April 25, 2012 02:43

yeah..i have...
If i undefine the thin cut, then prism gets created. If i define thin cut, then it does'nt..

OneDotThree April 25, 2012 09:04

I'm replying to this posts as I have problem similar to the previous ones.

I'm trying to create an unstructured mesh for a swirler. In fact I'm meshing 1/8 of the swirler and applying periodic conditions.

The problem is that some elements miss in proximity of some periodic face edges and appear in the corresponding periodic surface. in other words there is a hole at one side and there are exceeding elements (outside the surface) at the other side.

Moreover these elements have a low quality (below 0.2), so I can't ignore them.

I tried to use the define thin cutsoption and to define different values in the edge criterion but I couldn't resolve the problem.

I'm attaching some picture to explain better:
Attachment 12730 Attachment 12731 Attachment 12732

In the first picture in green you can see the periodic faces, in the second one the holes and in the third the elements outside the geometry.

I would be very grateful if someone could help me, thanks.

OneDotThree May 5, 2012 12:09

Could somebody give me an answer?
I resolved this problem accidentaly but it reappears if i change any mesh parameters (also in not involved parts).
It is very annoying, I've worked on it several days but I can't manage.
I would be able also to send you the project files.
Please help me!


All times are GMT -4. The time now is 18:59.