[snappyHexMesh] Little Help with SnappyHexMesh for Beginners

SimonStar · April 23, 2020, 06:47

Hello guys!

I'm trying to make a mesh with SnappyHexMesh.
I did several tutorials now and gererally I like it.

But there are two things i really worry about:

- Prismatic layers are collapsing from time to time
- My mesh is out of (often very sharp) triangles and not out of squares like in the tutorials.

To compare I got two pics for you: First my mesh and secondly a mesh from a tutorial (similar settings other geometry).

So waht can I do to make my mesh better?
Is the second issue maybe just becuase I have a false view and the mesh at itself is the same?
I world be very good to have it so nice than in the tutorial.

Thanks a lot
I'm happy about all help!

Yann · April 23, 2020, 07:50

Hello Simon,

Your second issue is just related to visualization in paraView :

When you create a slice in ParaView, uncheck "triangulate slice" to get rid of the triangles
If you want the same visualization than in the picture you have posted, check the "crinkle slice" option

About your first question : having a good prism layers coverage on your geometry can be a tricky thing to achieve with snappy. It takes some time to fiddle with the addLayersControls and meshQualityControls parameters.

Cheers,
Yann

SimonStar · April 23, 2020, 08:53

Hello, Yann!

Thank you for the very good information, it was herping me a lot.

So do I see it right that the slice with unchecked triangulation and wich checked 'Crinkle Mesh' is showing the real 3D-mesh - and only with checked triangulation its showing the 'normal CAD-surface-triangles'?

And are the prism layers better with another program?

Thank you

April 23, 2020, 07:50		#2
Yann Senior Member Yann Join Date: Apr 2012 Location: France Posts: 1,236 Rep Power: 29	Hello Simon, Your second issue is just related to visualization in paraView : When you create a slice in ParaView, uncheck "triangulate slice" to get rid of the triangles If you want the same visualization than in the picture you have posted, check the "crinkle slice" option About your first question : having a good prism layers coverage on your geometry can be a tricky thing to achieve with snappy. It takes some time to fiddle with the addLayersControls and meshQualityControls parameters. Cheers, Yann

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[CAD formats] Creating waterproof STL using snappyHexMesh or salome	Tobi	OpenFOAM Meshing & Mesh Conversion	58	May 13, 2020 07:01
[snappyHexMesh] Running snappyHexMesh in parallel - optimizing	peterhess	OpenFOAM Meshing & Mesh Conversion	2	January 3, 2018 03:54
[snappyHexMesh] Tutorial crashes: snappyHexMesh floating point exception.	jasv	OpenFOAM Meshing & Mesh Conversion	4	May 10, 2016 03:55
Strange Results With snappyHexMesh	calebamiles	OpenFOAM Running, Solving & CFD	0	August 14, 2011 17:02
[snappyHexMesh] stitchMesh and snappyHexMesh	gdbaldw	OpenFOAM Meshing & Mesh Conversion	0	December 23, 2009 03:09

April 23, 2020, 08:53		#3
SimonStar Member Simon Join Date: Sep 2019 Location: Germany Posts: 51 Rep Power: 7	Hello, Yann! Thank you for the very good information, it was herping me a lot. So do I see it right that the slice with unchecked triangulation and wich checked 'Crinkle Mesh' is showing the real 3D-mesh - and only with checked triangulation its showing the 'normal CAD-surface-triangles'? And are the prism layers better with another program? Thank you