CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > ANSYS Meshing & Geometry

[ICEM] O-grid around wing geometry

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree1Likes
  • 1 Post By PSYMN

Reply
 
LinkBack Thread Tools Display Modes
Old   September 28, 2009, 05:40
Default O-grid around wing geometry
  #1
Member
 
Join Date: Mar 2009
Posts: 52
Rep Power: 8
Anorky is on a distinguished road
Hi everyone,

First of all thanks for reading my thread.

I am currently scripting a geometry construction and mesh generation in ICEM.

I want to construct a fully structured O-grid around a 3D wing geometry. An illustration of my geometry can be found in the attached figures.

Since I will mesh several types of airfoils and different "wing shapes" I want the blocking to be automatic. By different wing shapes I mean the cornering (arc or ellipse form) and dimensions.

Therefore I was planning to use the 2D surface blocking function to create the surface blocking and than extrude this 2D blocking to a 3D blocking.

I have tried and used this option for a more simple geometry and that worked fine.

However for this geometry I haven't had any succes obtaining a good blocking.

To create the fully structured (boundary layer) O-grid around the wing, I constructed a boundary layer geometry around the wing. The idea is to block the fluid region in between the outer, boundary layer geometry, and the inner wing geomerty.

Now I do the following steps:
1) open the geomerty, (wing geomerty, boundary layer geomerty; both are connected in the symmerty plane by surfaces, see the figures)
2) 2D surface blocking with following settings: Method: Mostly mapped; merge mapped blocks is off; 2D Free block mesh type is all quads; Selected surfaces: All
3)2D to 3D; O-grid option is off, simple fill is off.

What I don't understand is why ICEM creates 3 split block for the outer rear symmetry surface. Resulting in also 3 blocks for the "triangular region" between the trailing edge. I can imagine that this "triangular region might cause some problems. I included a figure that will make the above more clear.

Has anyone a suggestion how to achieve a clean blocking?
Another solution would be to start with a 3D bounding block and split this block manually and associate the relevant vertices and edges to the geometry. However this would be to complex to script for my problem since the number of cornering section, and corner shape (arc or ellipse,...) will change often. I think this solution wouldn't be that flexible to implement in my script code as the 2D surface blocking method would be.

I might have made a fundamental mistake from the beginning on but for this moment I am out of ideas for valid solutions so I hope someone can help me.

Any ideas or suggestions are welcome. If something is not clear, please don't hesitate to contact me!

Thanks in advance!!

kind regards
Attached Images
File Type: jpg wing_geometry.jpg (49.1 KB, 329 views)
File Type: jpg wing_boundary_layer.jpg (56.8 KB, 373 views)
File Type: jpg isometric wing boundary layer view.jpg (41.5 KB, 271 views)
File Type: jpg 2D surface blocking.jpg (92.4 KB, 345 views)
File Type: jpg Resulting 3D blocking.jpg (70.1 KB, 276 views)
Anorky is offline   Reply With Quote

Old   October 12, 2009, 15:37
Default Try blocking it yourself...
  #2
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Yea, I would say the 2D blocking has not been ideal for this configuration, particularly with that lower block... It just sees the angles on that surface as too great to assume you want them mapped.

I would use scripting to record the interactive steps to generate an ideal 2D blocking.

I may be able to help with that if you want to send me what you have...
PSYMN is offline   Reply With Quote

Old   November 2, 2009, 05:55
Default
  #3
Member
 
Join Date: Mar 2009
Posts: 52
Rep Power: 8
Anorky is on a distinguished road
Hi Psymn,

Thanks for replying!

Sorry for my late response, I haven't checked the forum for a while.

It seems I solved to problem by doing the blocking in 2 stages.
I create a 2D surface blocking for the front parts. The degenerate blocks near the trailing edge are made manually.
Then I merge both blockings yielding the final blocking.

This seems to work

Regards
Anorky is offline   Reply With Quote

Old   November 3, 2009, 18:42
Default fully scripted...
  #4
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Great, but just for the record, a fully scripted solution is possible. Let me know if want to try for that.

Simon
PSYMN is offline   Reply With Quote

Old   November 5, 2009, 11:15
Default
  #5
Member
 
Join Date: Mar 2009
Posts: 52
Rep Power: 8
Anorky is on a distinguished road
Hi Simon,

I have wrote a script that does the trick automated.

I am trying to write scripts for the complete mesh and geometry creation.
The geometry is created by use of several input parameters. Afterwards the whole blocking process and mesh generation are done by use of scripts.
In the end this should allow the whole mesh and geometry creation to be fully automated. This will be very usefull for me since I want to try several different configurations.

When I started the scripting process I hoped it to be easier than it is
I find it relative difficult to find a good scripting reference/ manual.

The replay function works fine altough a lot of unnecessary lines are recorded as well in my point of view. But it works fine to find the correct commands and arguments.

Do you have good reference material concerning the tcl/tk commands in icem despite the provided manual?

thanks for replying on my post!

Kind regards
Anorky is offline   Reply With Quote

Old   November 16, 2009, 21:22
Default Programmers Guide?
  #6
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Did you already find the programmers guide under "help"?

You could also go to "scriptics.com"
PSYMN is offline   Reply With Quote

Old   November 17, 2009, 05:15
Default
  #7
Member
 
Join Date: Mar 2009
Posts: 52
Rep Power: 8
Anorky is on a distinguished road
Hi Simon,

Indeed, I already know the programmers guide. The scriptics website I found a while ago but has been under reconstruction since than...
Thanks for the suggestions and if you would know other reference material it would be more than welcome

kind regards and thanks for replying on my posts!
Anorky is offline   Reply With Quote

Old   November 18, 2009, 07:26
Default 3D Iced Wing Meshing
  #8
New Member
 
Join Date: Nov 2009
Posts: 1
Rep Power: 0
Crazy CFD is on a distinguished road
Dear All of Friends!
I am currently trying to generate the 3D Iced swept wing mesh generating in Gridgen V 15.
First, I really thanks all of you for reading my wirtting.
I want to generate a multi-block Hybrid mesh or Fully Structured C-grid around the 3D Iced swept wing geometry.

Has anyone a suggestion how to creat a hybrid or sturctured multiblock grid around the iced wing geometry?
I hope someone can help me that problems.
Please give me any idea and advice!
welcome!!!
Thank !!
Crazy CFD
Crazy CFD is offline   Reply With Quote

Old   November 18, 2009, 11:16
Wink Sell crazy some place else
  #9
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
What? Are you Crazy

This forum is mainly for ANSYS brand mesher (ICEM CFD Hexa, Gambit, TGrid, CFX Mesh, etc.), but there is another forum for Pointwise. You will probably find more Gridgen users there who can help you.

On the other hand, if you are interested in seeing how this would be done with ICEM CFD Hexa, I can help with that.
Attached Images
File Type: jpg Marconi_Multizone4.jpg (98.3 KB, 261 views)
File Type: jpg Copy of EuroCopter.jpg (97.3 KB, 247 views)
File Type: jpg SimpleFan__05_TopDownFirst.jpg (97.3 KB, 207 views)
File Type: jpg ICEM_MultiZone_F6.jpg (97.4 KB, 212 views)
File Type: jpg ICEM_OGRID_Merc.jpg (50.7 KB, 213 views)
PSYMN is offline   Reply With Quote

Old   November 21, 2009, 11:02
Default
  #10
Senior Member
 
John Chawner
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 221
Rep Power: 9
jchawner is on a distinguished road
Crazy:

As Simon says, join us crazy Pointwise people in the Main CFD Forum! Regardless, there are some very straight forward procedures for generating both hybrid and structured grids around wings and airfoils, iced or not. I would be interested in seeing the geometry first in order to get an idea of what we're talking about.

Simon: Thanks for pointing Crazy in our direction.
__________________
John Chawner / jrc@pointwise.com / www.pointwise.com
Blog: http://blog.pointwise.com/
on Twitter: @jchawner
jchawner is offline   Reply With Quote

Old   August 14, 2011, 03:10
Default
  #11
New Member
 
LL
Join Date: Jun 2011
Posts: 17
Rep Power: 6
aweizazuji is on a distinguished road
Hi Simon, I just want to ask how you coud generate structure grid on the surface of the body(like in your attachment --the wing) and the generate unstructure grid in the field(like delaunary method)? thanks. I did this before , first i have structure mesh by blocking method, then change to mesh, but like in the symmetric surface ,when meshing it, even i use repect line element command, the nodes do not merge. thank you1
aweizazuji is offline   Reply With Quote

Old   August 17, 2011, 16:02
Default
  #12
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
For those models (the nacel, the fan blade and the F6 aircraft), I just used the "MultiZone" method.

It is really ICEM CFD Hexa, but with an "unstructured" block to cover the difficult area around everything. It handles the connectivity, sweeping, delaunay, etc. all on its own.

There should be a couple new tutorials coming out with 14.0 in a few months, and one of them is a propeller shaft similar to that fan example.
lenovosk likes this.
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN is offline   Reply With Quote

Old   August 17, 2011, 21:28
Default
  #13
New Member
 
LL
Join Date: Jun 2011
Posts: 17
Rep Power: 6
aweizazuji is on a distinguished road
Thank you Simon, I am looking forward.
aweizazuji is offline   Reply With Quote

Reply

Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Simulation of Flow through Complex 3D Geometry EmersonKB CFX 5 July 2, 2009 08:17
2d irregular grid Remy Main CFD Forum 1 December 22, 2008 05:49
Obtain Geometry Data from a Grid File in CFX 10.0 ARJUN CFX 2 August 17, 2006 07:20
Grid Independence problem for simple pipe geometry chanchala FLUENT 13 November 20, 2003 09:24
GRID TO GRID INTERPOLATION in FLUENT calogero FLUENT 3 June 4, 2003 08:32


All times are GMT -4. The time now is 22:18.