# [blockMesh] blockMesh-grading &cell expansion ratios

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 April 16, 2013, 09:59 blockMesh-grading &cell expansion ratios #1 New Member   Luis Batista Join Date: Mar 2013 Location: Lisboa / Setúbal Posts: 17 Rep Power: 8 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 ); "

 April 16, 2013, 17:50 #2 Member   Yosmcer Mocktai Join Date: Apr 2013 Location: Behind a computer Posts: 50 Rep Power: 12 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.

 April 17, 2013, 04:31 #3 Senior Member     Anton Kidess Join Date: May 2009 Location: Germany Posts: 1,379 Rep Power: 25 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. __________________ *On twitter @akidTwit *Spend as much time formulating your questions as you expect people to spend on their answer.

April 17, 2013, 05:57
#4
New Member

Luis Batista
Join Date: Mar 2013
Location: Lisboa / Setúbal
Posts: 17
Rep Power: 8
Quote:
 Originally Posted by Yosmcer 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

April 17, 2013, 05:59
#5
New Member

Luis Batista
Join Date: Mar 2013
Location: Lisboa / Setúbal
Posts: 17
Rep Power: 8
Quote:
 Originally Posted by akidess 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

 April 17, 2013, 06:05 #6 Senior Member   Join Date: Aug 2010 Location: Groningen, The Netherlands Posts: 216 Rep Power: 14 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

April 17, 2013, 06:19
#7
New Member

Luis Batista
Join Date: Mar 2013
Location: Lisboa / Setúbal
Posts: 17
Rep Power: 8
Quote:
 Originally Posted by colinB 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.

Luis

 Tags blockmesh, cell expansion ratio