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snappyHexMesh does not snap

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Old   February 2, 2010, 13:50
Default snappyHexMesh does not snap
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roberto amaduzzi
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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
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Old   April 19, 2010, 03:55
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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,

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Old   April 19, 2010, 04:31
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Hello,

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

Thanks again.
Roberto
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Old   April 19, 2010, 08:28
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Quote:
Originally Posted by beto View Post
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 ?
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Old   April 19, 2010, 09:52
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roberto amaduzzi
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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 fc3.3536 -1.01565 -0.310555) cached surfaceIndex_:-1 current:0 ownCc3.35332 -1.01566 -0.314487)


Thanks again
Roberto
Attached Images
File Type: jpeg Schermata.jpeg (50.5 KB, 92 views)
Attached Files
File Type: txt snappyHexMeshDict.txt (4.8 KB, 19 views)
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Old   April 19, 2010, 10:34
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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!

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Old   April 19, 2010, 10:40
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Quote:
Originally Posted by beto View Post
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.
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Old   April 19, 2010, 11:51
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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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