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-   -   featureAngle sHM (http://www.cfd-online.com/Forums/openfoam-meshing-snappyhexmesh/106002-featureangle-shm.html)

Tobi August 15, 2012 02:59

featureAngle sHM
 
Hi all,

i am using sHM since 2 years and after the 7th OF-Workshop I read the sHM-Tutorials of Eugenede Villiers after Bruno told in a thread this nice link.

In the presentation there is described the function of "featureAngle".
If you set it to 180 you are able to build layers on the corners. I tried this but there is no corner layer. I tried a few featureAngles like:

30
60
120
150
180

but every mesh looked the same?
Is that function just implemented in the extended sHM version?
Tobi



SirWombat August 16, 2012 04:25

Hi Tobi,

AFAIK it works just fine. Just be sure you don't filter any cells by wrong quality settings!

Layercells around corners often result in a surrounding mesh that has quite heavily distorted cells. So check your quality setting to allow such cells!

G Jan

SirWombat August 16, 2012 05:08

3 Attachment(s)
Hi Tobi,

just to give you an example:
I used a cube blockMesh background mesh. Then I put a cube inside this one with SHM and used a few layers.

Those layer-cells are colored green.

The 1st image is with "featureAngle 50" The 2nd is with "featureAngle 60". This can be a little confusing because the angle is not referring to the two neighboring surfaces the layercells rest on, but to the cells normal vectors of those two neighboring cells. And on a 90 corner that angle is not 90 degrees but less!

The last image attached shows how i think the featureAngle works.

G Jan

Tobi August 20, 2012 07:16

Quote:

Originally Posted by SirWombat (Post 377329)
Hi Tobi,

just to give you an example:
I used a cube blockMesh background mesh. Then I put a cube inside this one with SHM and used a few layers.

Those layer-cells are colored green.

The 1st image is with "featureAngle 50" The 2nd is with "featureAngle 60". This can be a little confusing because the angle is not referring to the two neighboring surfaces the layercells rest on, but to the cells normal vectors of those two neighboring cells. And on a 90 corner that angle is not 90 degrees but less!

The last image attached shows how i think the featureAngle works.

G Jan

Hi Jan,
thanks for your replay. Well your post sounds very good but I thought that you get better cells with the layer generation at the corners?

Am I wrong?


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