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

[ICEM] Merging Hexa Meshes in ICEM

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 7, 2011, 20:21
Default Merging Hexa Meshes in ICEM
  #1
New Member
 
Martin
Join Date: Nov 2010
Posts: 23
Rep Power: 6
screech1987 is on a distinguished road
To model an aerodynamic body I have made the flow domain out of three seperate blockings. One being the majoirty of the flow, being rotated from a 2D blocking.
Then to improve quality in the centre of this freestream region, eradicating wedge shaped cells, I blocked this 'core' separately using a 3D O-Grid.

Now I have come to merge them, by loading in the separate blockings and merging the topologies by using the merge option by right-clicking on the blocking 'tree'.

The end result is essentially what I want but with the following problems:

1) Non-Manifold Vertices and Multiple Edges are detected during mesh checking. I assume this is due to there being two surface meshes at the blocking interfaces? If so how do I merge the meshes completely/fix the problem.

2) More of a preference, but is there a way to make the merged blockings output a mesh as a single region, i.e. the surface meshes found at the interfaces between the separate blockings are not produced.

Thanks in advance,

Martin
screech1987 is offline   Reply With Quote

Old   April 8, 2011, 02:08
Default
  #2
Member
 
jeevan kumar
Join Date: Mar 2009
Posts: 81
Rep Power: 8
jeevankumarb is on a distinguished road
if you post some images it will be much more clear to understand.

Thank you
jeevankumarb is offline   Reply With Quote

Old   April 8, 2011, 07:39
Default
  #3
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
For your first point, associate all your curves with the edges at the interfaces of your 2 mesh. I guess you are looking for a conformal merge, so you must have the same number of nodes on each edges of your interface, and the same node repartition.

As jeevankumarb said, pictures would help !
BrolY is offline   Reply With Quote

Old   April 8, 2011, 07:53
Default
  #4
New Member
 
Martin
Join Date: Nov 2010
Posts: 23
Rep Power: 6
screech1987 is on a distinguished road
Sorry, will try to upload some pics as soon as, just not in front of my normal PC today.

With regards to the assigning to curves and mesh spacings. I have associated the both interface edges to the same curves where relevant. Also have checked the number of nodes and spacings are the same on each edge before merge. and also after. The merged mesh looks as if the nodes are conforming across the interfaces matching up.
screech1987 is offline   Reply With Quote

Old   April 8, 2011, 08:03
Default
  #5
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 13
BrolY will become famous soon enough
I have juste re-read your first topic : have you tried to merge your blocking ??

You should convert your 2 meshes to "unstructured mesh", and then do the merging (merge nodes with an adequate tolerance, deelte the 2 interfaces). I think it should be better.
BrolY is offline   Reply With Quote

Old   April 8, 2011, 09:06
Default Remove Association to Surface...
  #6
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 36
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
It sounds to me like you are saying the merge worked (you had matching topologies and you merged all the verts). It is not actually necessary to match edge distributions as that is taken care of automatically...

So the remaining issue is that you have the interface faces still projected to something...

1) Check that the blocks in all three sections are in the same blocking material (like FLUID). If not, and you have different volume zones on purpose, your solver will want shells, even if they are later marked as internal walls.

2) If you are sure that you don't want/need internal shells, just go into Blocking => Associations and delete the association on those faces... Without association to surface, no shells will form.

Best regards,

Simon
__________________
-----------------------------------------
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   April 8, 2011, 13:13
Default
  #7
New Member
 
Martin
Join Date: Nov 2010
Posts: 23
Rep Power: 6
screech1987 is on a distinguished road
Thankyou for the replies so far.

I have attached some pictures as requested. A geometry Screen grab, A blocking screen grab, and a second blocking pic zoomed in on the hexa core.

Follwing on form the sugestions made, I created a body, and reset appropriate asscoaitions.
However, when creating a new body, i attempted to delete all previous ones, but none were present, so went ahead and defined one anyway.
Furthermore when restting associations I noticed duplications of blocking edges in the interface locations. I assume this is the cause of the errors encountered above in the previous post.
Also to note the resetting of associations and a new body did not solve my shell mesh at interfaces problem.

Cheers,

Martin
Attached Images
File Type: jpg Blocking.jpg (98.0 KB, 295 views)
File Type: jpg Geometry.jpg (41.0 KB, 216 views)
File Type: jpg Blocking_Core.jpg (101.6 KB, 216 views)
screech1987 is offline   Reply With Quote

Old   April 8, 2011, 13:19
Default
  #8
New Member
 
Martin
Join Date: Nov 2010
Posts: 23
Rep Power: 6
screech1987 is on a distinguished road
A couple more screen grabs of resulting mesh, and shells at interface and a region showing the duplicate edges (hard to tell)
Attached Images
File Type: jpg Blocking_NodeCoherence.jpg (94.1 KB, 144 views)
File Type: jpg Mesh_coreshell.jpg (94.1 KB, 193 views)
File Type: jpg Blocking_dupliicateedges.jpg (84.2 KB, 103 views)
screech1987 is offline   Reply With Quote

Old   August 24, 2012, 02:34
Default
  #9
Member
 
Fabian E.
Join Date: Nov 2009
Posts: 36
Rep Power: 7
galap is on a distinguished road
I have struggeld the last days trying to merge two hexa meshes having the same node distribution at the interface plane. PSYMN suggestion was helpful regarding the face issue but it was not the solution for the uncovered faces issue.

What I have done now:

I deleted the face associations at the interface section

then

Edit Mesh -> Check Mesh -> Uncovered Face -> found elements in subset

only visible elements in this subset -> Edit Mesh -> Merge Nodes by Tolerance -> set in a proper tolerance -> Apply

Edit Mesh -> Check Mesh -> Fix duplicate elements


that worked perfect for me!

PSYMN, If you read this: In the ansys support section there is a FAQ regarding the merge of two hexa meshes using "Merge volume meshes". I think you should distinguish between conform and not conform meshes.. No one wants pyramid elements when you work with conform meshes.
galap is offline   Reply With Quote

Old   August 28, 2012, 02:18
Default
  #10
New Member
 
Ozge
Join Date: Dec 2011
Posts: 2
Rep Power: 0
ozgulo is on a distinguished road
did you try t-merge? it is a utility of fluent. if you have two seperate mesh files with nearly the same distribution on the interface, and they are unstructured (i mean mesh method is unstructured not tetras), you can merge them with t-merge as far as i know.
ozgulo is offline   Reply With Quote

Old   August 28, 2012, 02:22
Default
  #11
Member
 
Fabian E.
Join Date: Nov 2009
Posts: 36
Rep Power: 7
galap is on a distinguished road
No I haven't, but now I have spoken with ANSYS support. The usual way is to merge different topologies. You do this in your blocking tree. Right click on root topology -> Merge. Blockings have to be in the same part.

Works perfect for me!
galap is offline   Reply With Quote

Old   March 13, 2014, 12:45
Default help me to mesh shell block geometry in icem
  #12
New Member
 
hemant ghule
Join Date: May 2013
Posts: 2
Rep Power: 0
hemant.ghule is on a distinguished road
help me to mesh shell block geometry in icem
hemant.ghule is offline   Reply With Quote

Reply

Tags
blocking, hexa, icem, merge, structured mesh

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
PEM Fuel cell module meshes. ICEM vs workbench aarvay FLUENT 20 August 5, 2015 21:04
[ANSYS Meshing] Workbench 13: Structured Hexa Meshes rooftop ANSYS Meshing & Geometry 18 May 13, 2014 03:57
Different results from similar quality cfx and ICEM meshes Nick R CFX 3 January 17, 2011 08:48
Hexa meshes with ICEM CFD 5.1 Tim Guo CFX 8 June 29, 2005 09:27
ICEM CFD 5.1 Hex-Tet mesh merging failure bogesz CFX 1 January 29, 2005 07:46


All times are GMT -4. The time now is 17:54.