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-   -   blockMesh-grading &cell expansion ratios (https://www.cfd-online.com/Forums/openfoam-meshing-blockmesh/116272-blockmesh-grading-cell-expansion-ratios.html)

 Luis Batista April 16, 2013 08:59

blockMesh-grading &cell expansion ratios

Dear openFoam Users,

please help me with this simple problem.

I would like to mesh a rectangular area using blockMesh with a grading function to manipulate the cell expansion ratio. This function would tighten the mesh dimensions near the domain boundary.The cell expansion ratio would need to be governed by a sinusoidal function.

In the example below we can read "simpleGrading" and I would like to have other solutions available.

Please explain me how this can be done or point me to similar threads in the forum.

PS:
I am a begginer, please mind that if you loose the time to help me:).

Regards,
Luis

"
blocks
(
hex (0 1 2 3 4 5 6 7) // vertex numbers
(10 10 10) // numbers of cells in each direction
simpleGrading (1 2 3) // cell expansion ratios
);
"

 Yosmcer April 16, 2013 16:50

I am also a beginner, but I saw here that there is an other function for grading:
edgeGrading

It deliver the possibility to grade toward each edge instead of only the directions, but I think you want something more. Hope however it helps.

 akidess April 17, 2013 03:31

blockMesh is a very simple tool, I doubt you can use it for this. Either you use a more sophisticated mesher like Pointwise or ICEM or such, or you need to write some code for blockMesh.

 Luis Batista April 17, 2013 04:57

Quote:
 Originally Posted by Yosmcer (Post 421043) I am also a beginner, but I saw here that there is an other function for grading: edgeGrading It deliver the possibility to grade toward each edge instead of only the directions, but I think you want something more. Hope however it helps.
Thanks for taking the time to help me.

Your intuition is correct. The option edgeGrading is not what exactly what I need.

Regards,
Luis

 Luis Batista April 17, 2013 04:59

Quote:
 Originally Posted by akidess (Post 421126) blockMesh is a very simple tool, I doubt you can use it for this. Either you use a more sophisticated mesher like Pointwise or ICEM or such, or you need to write some code for blockMesh.
Thanks for taking the time to help me.

I also feel that I have to write some code for blockMesh. Can you help me with this and/or point me in the right direction?

Regards,
Luis

 colinB April 17, 2013 05:05

Hey Luis Batista,

those guys were also not satisfied with the grading OF provides:

http://www.cfd-online.com/Forums/ope...e-grading.html

I'm not sure if it is exactly what you are looking for
however it eventually gives you a starting point
for own adjustments to the grading tools.

I hope I could contribute
regards

 Luis Batista April 17, 2013 05:19

Quote:
 Originally Posted by colinB (Post 421159) Hey Luis Batista, those guys were also not satisfied with the grading OF provides: http://www.cfd-online.com/Forums/ope...e-grading.html I'm not sure if it is exactly what you are looking for however it eventually gives you a starting point for own adjustments to the grading tools. I hope I could contribute regards
Hello,

It seems that you hit the spot!

I am going to investigate this thread further and come back with an answer and hopefully share my findings.

Thanks for your support,
Luis

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