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-   -   Troubles with "stitchMesh" (http://www.cfd-online.com/Forums/openfoam/87941-troubles-stitchmesh.html)

lentschi May 3, 2011 10:13

Troubles with "stitchMesh"
 
2 Attachment(s)
Hello everyone,

first I extended my single-channel-mesh (of a pump) "svwg0" with "transformPoints -yawPitchRoll "("16 0 0)"" (=16-rotation around the z-axis) and "mergeMeshes . svwg0 . svwg16" to get a 2-channel-mesh.
Then I performed "stitchMesh" with and without the flag "-perfect" and got two different errors (see log files in the appendix).

Does anyone know, how I can reduce the tolerance to 1e-06 for matching all the points? And what does "cannot determine best atan point" mean??

Thanks in advance.

Regards

stevenvanharen May 4, 2011 05:58

There is an option -toleranceDict. I don't know how it works but you can play around with it.

However, my advice would be to try to get the points within the standard tolerance. Maybe try mirrorMesh? Is this possible with your geometry?

lentschi May 4, 2011 10:05

Thank you for your answer,but there is no option -toleranceDict!

I cannot use "mirrorMesh", because I need to rotate my mesh!

Regards

stevenvanharen May 4, 2011 10:46

mmm, ok option maybe only avaliable in 1.7.1

In that case I don't have any tips anymore, sorry

lentschi May 5, 2011 04:16

oh,no problem - and thank you for your answer!

I am going to take a complete geometry from CFX, so I do not need merge- and stitchMesh any more.

I hope this works!!

Regards

suh August 11, 2011 05:59

hi stevenvanharen,

will you please tell me where is this toleranceDict file is in OF 1.7.1? I can not able to find its location.

and if you know how to use it, then please give some comments?

and is it possible for two patches with equal surface area but one with hexahedra and another with polyhedra mesh to stitch together by any other method in OF 1.7.1 (I tried stitchMesh, but after using this command then also it is showing some faces on that patch).

thank you.

stevenvanharen August 11, 2011 07:22

yes, you can stitch polyhydral with hexahedral, as long as the interface is conformal. This will be quite a strange situation though. Is your interface conformal?

I also couldn't find an example for the toleranceDict myself, so you have to play around with it to see how it works

suh August 12, 2011 03:50

Thank you for replying,

As you said i am able to stitch the hexahedral and polyhedral patches by adjusting some tolerance factor from toleranceDict file.

I will write detailed report on this after coming from holidays.

thanks again.:)
Regards
Suhas

Ralph M October 26, 2011 15:35

Hello Suhas,

I'm looking forward to your report!

Regards,

Ralph

dhruv October 27, 2011 04:53

http://www.cfd-online.com/Forums/ope...tml#post329665

Take a look here, may be you can find something :)
Quote:

Originally Posted by suh (Post 319851)
Thank you for replying,

As you said i am able to stitch the hexahedral and polyhedral patches by adjusting some tolerance factor from toleranceDict file.

I will write detailed report on this after coming from holidays.

thanks again.:)
Regards
Suhas


Ralph M October 27, 2011 05:01

Hi Dhruv,

I already read that post but was looking forward to the findings of Suhas. I tried to stitch to meshes; merging went fine but the stitiching was more difficult. I tried both -perfect and -partial flags, the toleranceDict, etc and I was hoping that Suhas would give me more insight in the toleranceDict.

If not I'll post my case over here :)

Ralph


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