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-   -   How to declare a prism block in the blockMeshDict file (http://www.cfd-online.com/Forums/openfoam-pre-processing/62074-how-declare-prism-block-blockmeshdict-file.html)

callega April 18, 2008 11:23

Hi, I'm a beginner in CFD
 
Hi,

I'm a beginner in CFD and obviously in OpenFOAM.
I had a lot of problems trying to convert FLUENT and ANSYS meshes files generated with ANSA, therefore I started to create a problemtype in GID which can generate blockMeshDict files for OpenFoam.

With the hexahedras blocks there is not probles, because in the manuals there are a lot of examples of declarations of this kind of element, but I'm having dificulties with the prism and tetrahedras blocks.

Following the syntax of hexahedron block,
hex (0 1 4 3 9 10 13 12) (10 10 1) simpleGrading (2 2 1)

I'm writing the prisms elements like this
prism (0 1 2 3 4 5) (10 10 1) simpleGrading (2 2 1)

but blockMesh is printing an error message:
"There are no non-lineal edges"

I think that the problem is in the declaration of the prism block. If someone knows how to declare this kind of block and the other kinds of blocks, diferents than the hexahedron, please help me!!!!

Regards

Sebastián

hjasak April 18, 2008 11:45

This should be in documentatio
 
This should be in documentation: Create a "hex" block, but re-use the vertices. For example:

hex (0 1 2 2 3 4 5 5)

Clear?

Hrv

CFDUser_ March 31, 2014 07:37

Regarding prism cells division
 
1 Attachment(s)
Quote:

Originally Posted by hjasak (Post 182238)
This should be in documentation: Create a "hex" block, but re-use the vertices. For example:

hex (0 1 2 2 3 4 5 5)

Clear?

Hrv

Dear Jasak,

Is it possible to make something like this (referred to attached picture)?

Regards
CFDUser

vangelis April 3, 2014 02:55

Hi Sebastian,

If you have ANSA why not output directly in OpenFOAM format
than try to output Fluent mesh and convert it?
You should not have any problem to output an OpenFOAM mesh from ANSA

Regards

Vangelis

Elisa-L May 21, 2015 05:44

Quote:

Dear Jasak,

Is it possible to make something like this (referred to attached picture)?

Regards
CFDUser
Attached Thumbnailshttp://www.cfd-online.com/Forums/att...file-prism.jpg

Hello,

I have to make something like this on openFoam for my job and I have a lot of troubles trying to do it, since I am new on openFoam. Could anyone help?

KateEisenhower May 26, 2015 07:37

Quote:

Originally Posted by callega (Post 182237)
Hi,

I'm a beginner in CFD and obviously in OpenFOAM.
I had a lot of problems trying to convert FLUENT and ANSYS meshes files generated with ANSA, therefore I started to create a problemtype in GID which can generate blockMeshDict files for OpenFoam.

With the hexahedras blocks there is not probles, because in the manuals there are a lot of examples of declarations of this kind of element, but I'm having dificulties with the prism and tetrahedras blocks.

Following the syntax of hexahedron block,
hex (0 1 4 3 9 10 13 12) (10 10 1) simpleGrading (2 2 1)

I'm writing the prisms elements like this
prism (0 1 2 3 4 5) (10 10 1) simpleGrading (2 2 1)

but blockMesh is printing an error message:
"There are no non-lineal edges"

I think that the problem is in the declaration of the prism block. If someone knows how to declare this kind of block and the other kinds of blocks, diferents than the hexahedron, please help me!!!!

Regards

Sebastián

Hi Sebastián,

I may be wrong but I think blockMesh doesn't support prisms with 6 vertices.
Quote:

Originally Posted by OpenFOAM User Guide
The principle behind blockMesh is to decompose the domain geometry into a set of 1 or more three dimensional, hexahedral blocks.

I would create the domain from your last post manually with gmsh and export the mesh to OpenFOAM afterwards.

Best regards,

Kate

hdietterich June 1, 2015 12:38

Quote:

Originally Posted by Elisa-L (Post 547151)
Hello,

I have to make something like this on openFoam for my job and I have a lot of troubles trying to do it, since I am new on openFoam. Could anyone help?

It is as hjasak says. You can make a prism block by simply reusing the vertices in a hex block description. You can do the same thing when defining the faces. It is described in the documentation here:

http://cfd.direct/openfoam/user-guid...25-1500005.3.3


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