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July 27, 2009, 07:36 |
Non Manifold Boundary
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#1 |
New Member
Ben
Join Date: Jun 2009
Location: Tasmania
Posts: 16
Rep Power: 17 |
Does any one know what this error is?
A minor internal error has occurred. You may continue to work but if problems arise they may be related to this error. Try using the check/fix function to fix the problem The following message was designed to aid developers fix the problem: non-manifold boundary at node 2081 any help would be great, I am creating a structured mesh using ICEM for a fully appended sub marine hull form, and i get this error when i try to create the boundary layer around the sub. any help would be great Ben |
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July 28, 2009, 09:56 |
Non-manifold
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#2 |
Senior Member
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
Blog Entries: 1
Rep Power: 47 |
A manifold node is a node with a ring of elements around it... (think a surface node with 8 nodes around it.)
A non-manifold node is a node with more than one ring of nodes around it. This can happen when you pinch two surfaces together. At the point where they touch, there is a ring of nodes on each of the surfaces that touch at that point. Other interesting combinations are also possible. It signals blocking that is inproperly connected or folded back onto its self, usually due to merge verts... |
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May 26, 2010, 05:30 |
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#3 |
Member
Neil Duffy
Join Date: Mar 2010
Posts: 34
Rep Power: 16 |
Hi, I am having a similar problem to Ben. I have created a block then mirrored the block about an axis which runs through one of the vertices. When I try to create an ogrid in either of these blocks I get the same non manifold boundary message as Ben. I attempted to split the vertice to solve the problem but it will not allow me to do so. I had the same problem when taking a top down approach to mesh the same geometry (2D planar).
Any help would be appreciated. Neil |
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May 26, 2010, 05:58 |
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#4 |
Member
Neil Duffy
Join Date: Mar 2010
Posts: 34
Rep Power: 16 |
Problem solved! My geometry has been extruded a very small amount (necessary to run a seemingly "2D" simulation in CFX). The problem arising from the non-manifold boundary was due to a vertice which had been associated with the opposite surface however all vertices appeared to be on the same plane because of the scale of the extrusion (0.01 mm).
Thanks for the post Simon, the problem dawned on me because of it. Neil |
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May 27, 2010, 09:57 |
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#5 |
Member
Neil Duffy
Join Date: Mar 2010
Posts: 34
Rep Power: 16 |
Unfortunately I spoke too soon regarding a solution to the problem. I encountered the same error later on at a different section of the geometry and all vertices were on the same plane. The only solution I found was deleting all blocks surrounding that vertice and attempting to reblock from different approaches. Eventually it worked but for no discernible reason. Further insight would be appreciated.
Neil |
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May 27, 2010, 14:51 |
Minor Error
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#6 |
Senior Member
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
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Rep Power: 47 |
That was a minor error... Probably not worth worrying about. Did it stop the mesh from generating? Did the elements look bad? If you want to send me your files, I can help you debug.
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May 28, 2010, 09:35 |
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#7 |
Member
Neil Duffy
Join Date: Mar 2010
Posts: 34
Rep Power: 16 |
It didn't stop me from creating a mesh , however, it was preventing me from creating an Ogrid which I required in order to properly capture the boundary layer. As I did not assign mesh parameters until I had the blocks created, I couldn't fully determine the effect it had on the elements.
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March 31, 2012, 03:52 |
manifold node
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#8 |
New Member
Bruce
Join Date: Mar 2012
Posts: 8
Rep Power: 14 |
I have a similar problem to this.
The geometry is illustrated in the attachment : the two bodies have different material propeties and heat source, so they must be seperated to two meterial point. But when I O-grid the blocks , the manifold occured. |
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March 31, 2012, 10:59 |
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#9 |
Senior Member
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
Blog Entries: 1
Rep Power: 47 |
XJTH... Sorry I don't understand what "occurred".
As for blocking materials, you must actually assign the blocks to the materials. It is an interactive step, not merely a flood fill. To do so, right click on the body you want to add blocks to, change the option to blocking material and then select the blocks... Apply... Best regards,
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