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Old   November 23, 2014, 08:37
Default non manifold
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senthur rajasekar
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I have geometry with ac duct with 3 diffusers ,inside a domain.there is no thickness
For anything..at inlet it shows non.manifold (inlet surface...ac duct surface...and domain surface which are connected on same place)...iam having only one region (because only onr fluid is passing all over domain)..if i split into two regions(ac duct and remaining) , ac duct has openings in diffuser.shows not closed region...what to do...
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Old   November 25, 2014, 11:58
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can you be a bit more clear? I dint understand the problem.
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Old   November 25, 2014, 12:41
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not volume meshing showing non-manifold. ac duct it has three diffusers where fluid enter through it. whole domain is of only one fluid. at inlet it enters , spreads through diffusers,, and comes from outlet. how to split this geometry for volume meshing. at inlet and outlet it has non.manifold edges. i dont know how to split this geometry , because ac duct has diffusers open. if i have one region for ac duct and inlet( diffusers is open not closed)and other region as other parts and outlet , it also has non.manifold. how to split this and volume meshing.
for volume meshing,
1. we should need to split regions , if fluid is one on whole domain.but has non. manifold edges?
2. we cannot volume mesh with one region?
i have attached picture of my geometry.sadasad.jpg
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Old   November 26, 2014, 04:18
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I am not sure I still understand your geometry. Non-manifold edges appear if you have more than 2 faces attached to the same edge.
I am guessing in your case, that at the inlet(or the outlet), there are three faces attaching to an edge - one is on the inlet boundary, one is on the inner surface of the duct and the third is the thickness of the duct. But, I am not sure what it is.

Try using the wrapper to extract the fluid volume. The wrapper will get rid of the non-manifold edges and should give you a clean geometry to work with. There are tutorials on how to use the wrapper in the starCCM help.
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Old   November 28, 2014, 02:22
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When initializing mesh ,shows warning message that"part surface ...... is not associated with any boundary". And also when clicking region ,the part surface is not highlighting.what is the reason.

1. When surface wrapping,the non.manifold edges are accepted ah.i want that non.manifold edges?(you mentioned in previous reply).
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Old   November 28, 2014, 03:04
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Quote:
Originally Posted by senthur View Post
When initializing mesh ,shows warning message that"part surface ...... is not associated with any boundary". And also when clicking region ,the part surface is not highlighting.what is the reason.

1. When surface wrapping,the non.manifold edges are accepted ah.i want that non.manifold edges?(you mentioned in previous reply).
The warning just says that one or more of the part surface is not assigned to any boundary in any region. Just make sure that all the part surfaces you want to include in the simulation are assigned to a boundary. If that is the case, you may ignore the warning.

For highlighting the part in a scene, try right click and highlight. If it doesn't work, may be there are no faces in that boundary. check into that. also try to display that region/boundary in a scene. Sometimes it wont highlight but it will show.

You CANNOT have non-manifold edges while generating volume mesh. If you want to model a junction, you need to model it like shown in the attached image.
Attached Images
File Type: jpg Picture1.jpg (19.9 KB, 11 views)
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Old   November 28, 2014, 11:22
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1.highlight by right clicking thr region.
2.there is a boundary in the region
3.edited in scene/plot
4.gave set boundary on part by right clicking.
All things i have tried ,but not showing.
5.I tried to split into 3 regions by copying the boundary(convert to interface) andcreate new region from boundaries (since it is a junction).after that i selected that region.its highlighted.then i clicked mesh initialization.it showing error(previous reply)
What i need to do.

You showed me the pic how to model junction. we need to split into two regions even if there is a single phase ina single domain. ( i think that is what i tried to split into diff. Regions .(see 5 am i right)
Will u pls give ur email id.i ll send the model of me..can u pls explain that.
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Old   November 28, 2014, 12:43
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Another error.
When attempt to volume mesh showing"check material boundary:surface is not qualified for meshing" what to do.?
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Old   December 1, 2014, 02:56
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If your boundary is not showing, may be there are no triangles in it. Try changing the representation. May be there are no faces in a particular representation.

You need not split them into 3 regions. You can have them all in the same region, but the place where the two surfaces meet should be modelled like that.

e-mail will be of no help. I cannot access starccm+ at home (no license) and I cannot download files at work.

Go through the tutorials. The issues you have are pretty basic. May be once you go through the tutorials, you will be able to solve them easily.
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Old   December 1, 2014, 06:37
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Yes, i saw in representation.but the surfaces which are not showing appears in black in colour.and also there is no triangles on that surfaces..in that case what i need to do .
Thank you for your previous replies.
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