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-   -   [ICEM] Elements with surface orientation problem (http://www.cfd-online.com/Forums/ansys-meshing/102075-elements-surface-orientation-problem.html)

SH_P May 21, 2012 13:04

Elements with surface orientation problem
 
Dear freinds,

I am going to mesh a 3D model with ICEM. when I use only tetra elements I have no problem and Mesh checking process passes well.
But as soon as I create a layer of prism elements on walls, checking process says there are some elements with orientation problem. there are only 3-4 elements with this issue but I don't know how to fix them.
As it is shown in the picture they seem to be useless. Any way I can not simply delete them, as their faces remains.:confused:
Please help...

http://4ax.ir/images/snap201205.png
http://4ax.ir/images/snap20umu.png

gashishr May 22, 2012 00:14

I am also facing same problem. Only solution I found is, reduce the prism layers and remesh!!!

SH_P May 22, 2012 00:29

Actually the problem arises only in the part of the model in which two surfaces are matching which is fairly a simple geometry (see the figure).
It is very weird that there is no such an error in other parts which are more complex. Does anybody else know anything about this?
Thanks...
http://4ax.ir/images/snap20rir.png

SH_P May 22, 2012 00:51

Update: I have noticed that the problem is originated from the mesh without prism layer itself. As you can see in the picture, some of the elements on the top surface are not correctly captured from the geometry and this can cause problem when trying to mesh them with prism.
Now my question is that > Is it possible to manually assign as element to a specific "part" ; for example: assign specified elements to the outer wall instead of top wall?

Thanks...

http://4ax.ir/images/snap20clc.png

Ralen May 22, 2012 01:27

Attach the project.

gashishr May 22, 2012 02:01

@SH_P, you should have curves extracted at the intersection then only you will get proper elements on top and side surfaces.

Far May 22, 2012 02:18

I agree with "gashishr"

SH_P May 22, 2012 02:43

Thanks gashishr and Far. You are great...!

yonchong June 13, 2012 08:27

Moving elements to a part
 
I agreed that you should have lines between the surfaces and your geometry does not look very smooth. You might want to import the geometry using the Parasolid format.

However, you can move the element to different part:
  1. Select Edit Mesh tab (if you are in Geometry tab you will be selecting geomtry).
  2. Press the right button on the mouse at the part where you want to put the elements in.
  3. Select elements and apply.

BrolY June 14, 2012 03:43

Simon created a "pdf" document which explain how to deal with this problem.
Search threads on this forum with the same problems, and you will find out the solution.

Anyway, reduce the edge criteron and increase the number of nodes on those edges should help a lot.
Another thing, always do a build topology before meshing, and check if your edges are good.


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