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

[ICEM] Merge meshes with internal wall

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 20, 2013, 04:14
Default Merge meshes with internal wall
  #1
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
I have 2 projects : tube and cube (.tin .blk .uns .prj attached).

The inlet is located at the down part of the tube, and the outlet at the top part of the cube. The top of the tube is open into the cube. And the walls of the tube which are inside the cube (almost half of the tube) are internal wall.

My goal is to merge those 2 meshes, and at the end, to have only 1 volume (fluid). I opened ONLY the cube_only.uns and tube_only.uns files, and I merged the nodes the wall of the tube which is inside the cube with the correspondant part, and deleted one of the interface. Next, I tried to specify the remaining tube wall (which is inside the cube) as an internal wall. But this option is gray tint.

How am I sure that this interface will be considered as an internal wall by my solver ? (let's take as an example FLUENT) Was it the right way to do it ?
I tried to specify one of the interface as an internal wall when I created the blocking, but after I imported the .uns file, the option was gray tint.
Attached Files
File Type: zip CUBE_ONLY.zip (36.8 KB, 9 views)
File Type: zip TUBE_ONLY.zip (29.7 KB, 4 views)

Last edited by BrolY; February 20, 2013 at 04:40.
BrolY is offline   Reply With Quote

Old   February 20, 2013, 05:31
Default
  #2
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
You can merge blocking as well.


You want to keep the interface (2 and 3) ?
Far is offline   Reply With Quote

Old   February 20, 2013, 05:38
Default
  #3
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
What do you mean by 2 and 3 ?

Attached the merge I've done as I explained in the previous post. I merged nodes (Edit Mesh -> Merge Nodes) of INTERF_WALL and INTERF_WALL_01, and then delete INTER_WALL_01.

I don't know if Fluent (or another solver) would consider INTERF_WALL as a separation between the fluid from the tube and the cube because I can't specified INTERF_WALL as internal wall.
Attached Files
File Type: zip MERGE.zip (38.8 KB, 4 views)
BrolY is offline   Reply With Quote

Old   February 20, 2013, 05:58
Default
  #4
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
You want the internal wall as interior or wall? Int wall is really used to define the wall.

You are merging two hexa meshes? Which I dont think is good idea. Better idea would be to merge blocking and you have the full control over everything.

If you want to get the int wall option, do this!!!

1. Load mesh

2. Edit > Mesh >>> Facets

3. Define int-wall in part mesh setup
Far is offline   Reply With Quote

Old   February 20, 2013, 06:06
Default
  #5
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Please find enclosed fluent file. Do you want mesh like this?
Attached Files
File Type: zip MERGE.zip (38.8 KB, 4 views)
Far is offline   Reply With Quote

Old   February 20, 2013, 06:16
Default
  #6
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
I just want the solver to understand that this wall is a wall, not shells which should not be here (2D thickness). So the fluid can't go throught this wall.
I've done that only with Tetra and I know that the option "int wall" tells the mesher (basically) "it's a wall, dont delete those shells". After I can specify those shells as a wall when I export my project.
My problem is I'm facing a mesh created by a merging of 2 hexa meshes and 2 interfaces at the end. So I don't know if merging the nodes, and deleting one of the interface would led to what I'm looking for. If I merge nodes, would it connect the volume mesh from the 2 sides of the interface and at the end, the solver would consider the shells between the volume as a wall ? Or would it consider the shells as an error and just delete them ?

That is just a simple example, but my geometry is more complicated.
Merging blocking is a good idea, but I have something like 8 blocking.
I've noticed that at some point, it's really "heavy" to ICEM to handle it (crash, slow-down ..).

So merging unstructured meshes appeared to be the best solution.
And I want to keep Hexa, not to go with facets ... because facets means to convert your mesh to tetra, am I right ?
BrolY is offline   Reply With Quote

Old   February 20, 2013, 06:21
Default
  #7
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by BrolY View Post
So merging unstructured meshes appeared to be the best solution.
And I want to keep Hexa, not to go with facets ... because facets means to convert your mesh to tetra, am I right ?
Here mesh > Facets is used to extract the geometry from underlying mesh. and once you have geometry you can specify wall as int wall in part mesh. May be in background triangulation is used to make the surfaces but it does not mean that you are converting your hexa mesh into tetra.

I find this thread interesting.
Far is offline   Reply With Quote

Old   February 20, 2013, 06:31
Default
  #8
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
Ok, so ICEM needs the geometry to create internal wall ? It means that when you export your mesh with internal wall, you always need to have the geometry file in your project, and not only the mesh ?

I'm still wondering if it would works. If the process merge nodes + delete one of the interface would not have created problems.

Thanks for your help
BrolY is offline   Reply With Quote

Old   February 20, 2013, 09:11
Default
  #9
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Did you check the fluent file I just uploaded?
Far is offline   Reply With Quote

Old   February 20, 2013, 09:23
Default
  #10
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
There are only .prj and .uns file.

That looks like to the projet I've uploaded in my 2nd post. How did you proceed at the end ?
BrolY is offline   Reply With Quote

Old   February 20, 2013, 09:37
Default
  #11
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Oh wrong file .
Attached Files
File Type: zip fluent.zip (62.0 KB, 3 views)
Far is offline   Reply With Quote

Old   February 20, 2013, 11:10
Default
  #12
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Canada
Posts: 1,291
Blog Entries: 23
Rep Power: 20
diamondx will become famous soon enough
@broly, i understand what you want.
I once was wondering if this was doable, but never had the chance to test it out.
Now that i did,i am missing something because it cant be so easy...
When i opened your merged project where you have merged the two meshes. You left only the inter_wall. You want that to be a wall in the output menu, i specified inter_Wall as wall. it worked and it created a shadow in fluent. isn't it what you want ??
I guess no...
__________________
Regards,
New to ICEM CFD, try this document --> http://goo.gl/G2gkE
Ali
diamondx is offline   Reply With Quote

Old   February 20, 2013, 11:15
Default
  #13
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
i'm not really familiar with Fluent, so what does "shadow" mean ?
Is it a 2D wall surronded by fluid (but keeping them from being connected) ? If yes, that's what's I'm looking for !
BrolY is offline   Reply With Quote

Old   February 20, 2013, 11:16
Default
  #14
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
For internal wall (inside fluid) you have two sides. one is wall and second its shadow (other side)
Far is offline   Reply With Quote

Old   February 20, 2013, 11:21
Default
  #15
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
So that's good I think. For each part of the fluid, it's a wall.

Also, it means that I don't need to define the INTERF_WALL as an internal wall.
The "internall wall" option is only for the mesher. Am I right ?
BrolY is offline   Reply With Quote

Old   February 20, 2013, 11:22
Default
  #16
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Canada
Posts: 1,291
Blog Entries: 23
Rep Power: 20
diamondx will become famous soon enough
yes it is a 2d wall surrounded by a fluid. i guess fluent makes a shadow of that wall because you have elements in both side of the wall. where you usually have only one side...
__________________
Regards,
New to ICEM CFD, try this document --> http://goo.gl/G2gkE
Ali
diamondx is offline   Reply With Quote

Old   February 20, 2013, 11:32
Default
  #17
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Canada
Posts: 1,291
Blog Entries: 23
Rep Power: 20
diamondx will become famous soon enough
I feel like you are planning to do multiple separated blocks, and merge them... isn't easier to do one blocking ?
for a perfect merge, the node should be in the exact location... did you create a sub-topo for this one ?
__________________
Regards,
New to ICEM CFD, try this document --> http://goo.gl/G2gkE
Ali
diamondx is offline   Reply With Quote

Old   February 20, 2013, 11:33
Default
  #18
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
Thank you guys !
I guess we all have learned something today
BrolY is offline   Reply With Quote

Old   February 20, 2013, 11:39
Default
  #19
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by BrolY View Post
So that's good I think. For each part of the fluid, it's a wall.

Also, it means that I don't need to define the INTERF_WALL as an internal wall.
The "internall wall" option is only for the mesher. Am I right ?
You have to explicitly tell ICEM to treat extended surface as wall, otherwise it will not recognise it and think it is by error and removes the shell elements.

For tetra mesh, you define it in part mesh setup, whereas in Hexa it is defined by making the face to surface association explicitly
Far is offline   Reply With Quote

Old   February 20, 2013, 11:41
Default
  #20
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by diamondx View Post
I feel like you are planning to do multiple separated blocks, and merge them... isn't easier to do one blocking ?
for a perfect merge, the node should be in the exact location... did you create a sub-topo for this one ?
Sub topo is much better idea than merge
Far 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
Radiation interface hinca CFX 15 January 26, 2014 18:11
[GAMBIT] internal 2D wall in 3D model? ghost82 ANSYS Meshing & Geometry 2 September 11, 2012 03:25
[ICEM] merge two hexa meshes gajemon ANSYS Meshing & Geometry 1 January 29, 2011 20:49
deleting internal wall HK CFX 1 March 16, 2007 09:54
Wall functions Abhijit Tilak Main CFD Forum 6 February 5, 1999 02:16


All times are GMT -4. The time now is 22:28.