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-   -   [ANSYS Meshing] Fluent quality criteria in AM and Gambit (http://www.cfd-online.com/Forums/ansys-meshing/98766-fluent-quality-criteria-am-gambit.html)

Far March 18, 2012 19:52

Fluent quality criteria in AM and Gambit
 
In old times (Fluent 6.3), I used to create girds using GAMBIT (the ultimate power to user), the main grid criteria was to avoid skewness higher than 0.98 and. Lower the better.

Recently I have observed that when mesh is checked in Fluent (V 13 & 14), skewness criteria is no more there. Instead now I get the message about the orthogonality quality (0 worst, 1 best) and it is suggested in ANSYS meshing (AM) that avoid orthogonality quality below 0.05.

So far so good.

The real question is that :

Did Fluent improved and changed the algorithm; like CFX, you don't get message about skewness, rather one should be careful about min orthogonality angle, aspect ratio and volume change; in handling the mesh?

OR

Orthogonality and skewness has some relationship and any details about it?

Far March 19, 2012 08:53

Quote:

Orthogonality and skewness has some relationship and any details about it?
Roughly speaking orthogonality = 1 - skewness and vice versa

jsm March 24, 2012 03:14

Hi Far,

I also have same doubt about orthogonal quality and asked Tech support. I got this information.

"This is the other way to represent the quality of mesh like skewness.

And there is no change in algorithms
"

banty March 24, 2012 04:06

yes, orthogonal quality is just another methodology to represent the mesh quality. and I think it more meaningful in sense of the way flux is computed at cell faces.
here is full description of mesh quality
http://www.sharcnet.ca/Software/Flue...h_quality.html

Far March 24, 2012 04:12

link is not working

banty March 24, 2012 04:32

Please add https:// when u open the browser. its working for me.
I have uploaded doc file here
http://www.4shared.com/file/2atTeq5T/file.html?

Far March 24, 2012 04:35

correct. Working now


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