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-   OpenFOAM Native Meshers: snappyHexMesh and Others (https://www.cfd-online.com/Forums/openfoam-meshing-snappyhexmesh/)
-   -   snappyHexMesh does not snap (https://www.cfd-online.com/Forums/openfoam-meshing-snappyhexmesh/72336-snappyhexmesh-does-not-snap.html)

beto February 2, 2010 13:50

snappyHexMesh does not snap
 
Hello!

I know that this topic has already be covered, but I did not find any solution reading previous posts.

I would like to use snappyHexMesh for my meshes, it would be perfect. I found no way to obtain snapped surfaces on my geometry, simply stepped surfaces as after refinement and no output error.

Any suggestion on what I mistaked or what can I work on?

Thanks!
Roberto

marine April 19, 2010 03:55

Hello !

I had the same problem whit my mesh, here are two things I changed and which made my snappyHexMesh work :

-Be sure the ratio of cells in your blockMesh is next to 1.
-Do not define a refinement box with a to high level, start with small levels.

To economise time I used to run only the steps 1 and 2 of snappy.

hope it helps,

Marine

beto April 19, 2010 04:31

Hello,

Thanks for your reply!
Yes, I used exactly 1x1x1 ratio cels, I'll try to work better with refimement box.

Thanks again.
Roberto

romant April 19, 2010 08:28

Quote:

Originally Posted by beto (Post 244649)
Hello!

I know that this topic has already be covered, but I did not find any solution reading previous posts.

I would like to use snappyHexMesh for my meshes, it would be perfect. I found no way to obtain snapped surfaces on my geometry, simply stepped surfaces as after refinement and no output error.

Any suggestion on what I mistaked or what can I work on?

Thanks!
Roberto


How did u check the mesh? Does it give you two different "time steps" ? Can you attach the snappyHexDict ?

beto April 19, 2010 09:52

2 Attachment(s)
Hello Roman,

I apreciate very much your help, thanks!

I checked the mesh with paraview (see printscreen attached).
I create perfect cube hex with blockmesh.
I played a long time with refinement parameters with no conceptual change.
The command writes not two, but 19 timesteps with each refinement step.

I noted that the command ensd without error, but I have a lot of warning like:
--> FOAM Warning :
From function meshRefinement::checkData()
in file autoHexMesh/meshRefinement/meshRefinement.C at line 352
Boundary face:1520191 fc:(3.3536 -1.01565 -0.310555) cached surfaceIndex_:-1 current:0 ownCc:(3.35332 -1.01566 -0.314487)


Thanks again
Roberto

marine April 19, 2010 10:34

To see only the steps corresponding to 1) refinement 2)snapping you can define "debug" as 0.
I think to do a refinement region you have first to define a refinement box in the geometry part, for example :
refinementBox1
{
type searchableBox;
min (-10 -5 -5);
max (310 155 155);
}

and this is the region you can refine in the "refinementRegion."

Tell me if it works!

Marine

romant April 19, 2010 10:40

Quote:

Originally Posted by beto (Post 255270)
I checked the mesh with paraview (see printscreen attached).

At the moment I can see that you are looking at the first time step in paraview.

Do you see the time step option at the top of paraview. try going one or more time steps up (snapping should be the second time step and layers adding the third time step).

If you still do not see any refined pieces, that I will take a look at you dictionary again.

beto April 19, 2010 11:51

Roman, the case the printscreen is refered is not the refined one. I already inported the polimesh and delated all the debugging timestep. It's ready for the solver.

Marine,
thanks, I'll try to implement the refinement box!


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