CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Meshing tricks

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 29, 2010, 02:00
Default Meshing tricks
  #1
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 17
Mohsin is on a distinguished road
hello

Could anyone please tell me how can i mesh the following figure minimum skewness (equiangle skew should be less than 0.6). It is actually a part of a cylinder with 3 inner loops i-e the cylinder is connected with 3 pipes from where air will enter. I tried Cooper but its not possible. Tetrahedral is possible but it gives me high skewness greater than 0.85.

Is there any tricky way like real splitting, virtual splitting, decomposing etc etc through which i can apporoach this case.

I will be grateful for help. Thanks
Mohsin
Attached Images
File Type: jpg part of cylinder.jpg (30.8 KB, 21 views)
Mohsin is offline   Reply With Quote

Old   October 29, 2010, 02:07
Default
  #2
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
post a picture from your 3d domain.
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   October 29, 2010, 02:12
Default
  #3
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 17
Mohsin is on a distinguished road
thats the picture.

The middle portion of the cylinder.

I actually i created this red portion by purpose in order to apply cooper meshing scheme above and below that portion. But because of the three pipes circular regions cooper meshing cannot be applied in that red portion and tetrahedral gives high skewness.
Attached Images
File Type: jpg 3D cylinder.jpg (36.5 KB, 19 views)
Mohsin is offline   Reply With Quote

Old   October 29, 2010, 02:51
Default
  #4
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
You can mesh it wih cooper: try to split your volume by enforcing gambit to project each cylinder intake following a special direction
I did it very quick, and of course you can expect having better quality (hardly linked with angle of splits)
Maybe there is other tricks... but this one works.
Why do you want max skewness about 0.65? (it is quite low)
Sans titre.jpg
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   October 29, 2010, 02:59
Default
  #5
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 17
Mohsin is on a distinguished road
thank you Max.

before you were posting here i tried tetrahedral mesh and used size function approach. In that red portion i used "fixed size function" with 1.5 growth rate which gave me about 0.74 equiangle skewness.

Cooper meshing generally gives good quality. Your approach is very good as u splitted the circular regions and applied mesh. I will try it on my geomtery and will see the results and will post in a while.

As u asked about why i want below 0.65. Thats because lesser skewness greater mesh quality. 0.5 to 0.65 around is considered a good quality mesh design.

thank ypou again MAx
Mohsin is offline   Reply With Quote

Old   October 29, 2010, 03:06
Default
  #6
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 3,297
Rep Power: 41
-mAx- will become famous soon enough
I used everyday tet-hexcore with combination of size function. This way is very powerfull since you can reach a "good" quality (max skewness 0.9) for complex geometry in few hours.
From my side (and my applications) max skewness is enough (and good results in comparison with experiments
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[GAMBIT] Desperate student needs help meshing 3D GAMBIT model - please help! lau06165 ANSYS Meshing & Geometry 1 March 22, 2010 01:09
Best Meshing scheme for Cylinder Nutrex Main CFD Forum 4 July 29, 2008 11:03
Meshing locks workbench window. andy2o CFX 0 February 1, 2008 05:01
Singularity of grid?Volume meshing vs face meshing Ken Main CFD Forum 0 September 4, 2003 11:09
Volume Meshing & Face Meshing? singularity of grid ken FLUENT 0 September 4, 2003 11:08


All times are GMT -4. The time now is 06:16.