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April 12, 2005, 08:55 |
BlockMesh grading calculator
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#1 |
Senior Member
Markus Hartinger
Join Date: Mar 2009
Posts: 102
Rep Power: 17 |
Hi everybody,
i've written a calculator for the grading in the blockMesh format some time ago. It relates length, number of cells, total expansion ration, cell-to-cell expansion ratio, start cell size and end cell size. Given the length and any two of the other, the remaining values are calculated. It's a little programm, but I found it myself useful generating meshes with blockMesh. If someone improves it, let me know MeshSpace.tar.gz regards Markus |
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April 12, 2005, 10:36 |
Actually, the grading factor i
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#2 |
Senior Member
Hrvoje Jasak
Join Date: Mar 2009
Location: London, England
Posts: 1,907
Rep Power: 33 |
Actually, the grading factor in blockMesh is defined as the ratio of the last to first cell size, which is much better behaved that defining the number of cells and the geometric expansion ratio. I suppose we have both done the same thing :-)
Hrv
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Hrvoje Jasak Providing commercial FOAM/OpenFOAM and CFD Consulting: http://wikki.co.uk |
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December 19, 2006, 01:09 |
Hi Markus,
Thanks for the u
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#3 |
Senior Member
Srinath Madhavan (a.k.a pUl|)
Join Date: Mar 2009
Location: Edmonton, AB, Canada
Posts: 703
Rep Power: 21 |
Hi Markus,
Thanks for the utility. I found it very useful; esp. to find out the number of cells when one knows the start and end cell sizes in addition to the length. I had to edit the Makefile to remove the reference to the bin subdirectory which does not exist. A sample of the utility usage is shown below for those who need to know how to use it: madhavan@karmayug:~/MeshSpace$ ./MeshSpace ds de 0.58 0.000625 0.003125 Meshspace results by Markus.Hartinger@imperial.ac.uk : Length L : 0.58 Number of cells n : 373 Total expansion ratio r : 5 Cell-to-cell expansion k : 1.00434 Start cell size ds: 0.000625305 End cell size de: 0.00312652 madhavan@karmayug:~/MeshSpace$ |
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February 6, 2007, 05:08 |
Hi Markus
Would you please
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#4 |
New Member
Armin Hosseinian
Join Date: Mar 2009
Location: Perth, Western Australia, Australia
Posts: 17
Rep Power: 17 |
Hi Markus
Would you please tel me how your calcualtor works? i Couldent open that. Cheers |
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August 26, 2008, 19:29 |
I get this error with gcc 4.3.
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#5 |
Senior Member
Srinath Madhavan (a.k.a pUl|)
Join Date: Mar 2009
Location: Edmonton, AB, Canada
Posts: 703
Rep Power: 21 |
I get this error with gcc 4.3.1 when running make.
Any idea what is wrong? g++ -g -c MeshSpace.cpp MeshSpace.cpp: In function 'int main(int, char**)': MeshSpace.cpp:35: error: 'exit' was not declared in this scope MeshSpace.cpp:38: error: 'atof' was not declared in this scope make: *** [MeshSpace.o] Error 1 |
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September 1, 2008, 17:25 |
Problem solved. It was just a
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#6 |
Senior Member
Srinath Madhavan (a.k.a pUl|)
Join Date: Mar 2009
Location: Edmonton, AB, Canada
Posts: 703
Rep Power: 21 |
Problem solved. It was just a question of adding:
#include <cstdlib> to MeshSpace.cpp and TEdgeSpace.cpp |
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July 21, 2010, 10:36 |
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#7 |
Member
Alessandro
Join Date: Nov 2009
Posts: 67
Rep Power: 17 |
Sorry, which is the problem??
5:45 ale@alien:~/MeshSpace$ make g++ -g -c MeshSpace.cpp g++ -g -c TEdgeSpace.cpp g++ -g -o bin/MeshSpace MeshSpace.o TEdgeSpace.o /usr/bin/ld: cannot open output file bin/MeshSpace: No such file or directory collect2: ld returned 1 exit status make: *** [MeshSpace] Errore 1
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July 22, 2010, 08:37 |
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#8 |
Senior Member
David Boger
Join Date: Mar 2009
Location: Penn State Applied Research Laboratory
Posts: 146
Rep Power: 17 |
If you read back a few posts, Srinath has already given the answer to this problem (and the next one you'll encounter). Delete bin/ from the Makefile, and include <cstdlib> in both .cpp files.
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David A. Boger |
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July 22, 2010, 09:04 |
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#9 | |
Member
Alessandro
Join Date: Nov 2009
Posts: 67
Rep Power: 17 |
Quote:
Thank you
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September 4, 2010, 18:40 |
Stupid question..
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#10 |
Senior Member
Nilesh Rane
Join Date: Apr 2010
Posts: 122
Rep Power: 16 |
How to give the arguments to the program??? I didnt get it..
Sorry for this stupid question.
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Imagination is more important than knowledge..
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September 6, 2010, 04:19 |
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#11 | |
Member
Alessandro
Join Date: Nov 2009
Posts: 67
Rep Power: 17 |
Quote:
Look at the third post; it's just an example
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September 6, 2010, 06:44 |
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#12 |
Senior Member
Nilesh Rane
Join Date: Apr 2010
Posts: 122
Rep Power: 16 |
Oh yes...i just overlooked it..i was trying meshspace value ds value de value...etc
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Imagination is more important than knowledge..
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December 22, 2010, 06:02 |
Broken Link?
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#13 |
Member
P.A.
Join Date: Mar 2009
Location: Germany
Posts: 83
Rep Power: 17 |
Hi,
I cannot download the .tar.gz file. All I get is a short html file saying that the file I was looking for was not found on the server. This is saved with a .unk file extension. Using wget http://... brings the same result. Can anybody shed some light on this? Or send me the file via email to pascal \at\ pascal-anschau \dot\ de? Thanks in advance! Cheers, Pascal. |
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May 15, 2011, 13:14 |
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#14 | |
Member
Join Date: May 2010
Posts: 44
Rep Power: 16 |
Quote:
Just rename the downloaded file to "MeshSpace.tar.gz", extract it, then it should work. |
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June 16, 2011, 14:51 |
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#15 | |
Member
Alex
Join Date: Jun 2010
Location: Planet Earth
Posts: 43
Rep Power: 16 |
Quote:
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August 17, 2011, 13:31 |
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#16 |
New Member
Pam
Join Date: Feb 2011
Posts: 15
Rep Power: 15 |
Hi Srinath,
I am new to OpenFoam. I need to create a mesh for channel with non linear mesh. My node spacing is 12% increment for first 20 nodes near wall and 1.5 times viscous length scale and then 8% near the cwnter line and same on the otherside of the center line too.. I am confused how do I can take expansin ration? Thanks in advance, Prameela.
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Pam |
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August 17, 2011, 14:27 |
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#17 |
Member
Alex
Join Date: Jun 2010
Location: Planet Earth
Posts: 43
Rep Power: 16 |
Hi Pam,
I would suggest first learning how to use blockMesh utility with openFOAM. You will need to separate the mesh into separate blocks for each grading. First do a couple of the tutorials here to learn Then use hartinger's tool to specify the grading based on your requirement. Good luck. |
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February 27, 2012, 05:01 |
Blockmesh
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#18 |
Senior Member
kunar
Join Date: Nov 2011
Posts: 117
Rep Power: 15 |
Dear Foamers,
i have xyz coordinates(that is model have 33 coumns and 225 rows in .csv file format) how i import and create blockmesh andbody have idea please let me know. Thanks for the answer in advance! |
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April 8, 2012, 10:32 |
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#19 |
New Member
Kirill Cherniy
Join Date: Apr 2012
Posts: 3
Rep Power: 14 |
first: are these coordinates of block vertices?
second: if so u can easyli write converter that will pull vertices of that file and create blocks, faces and edges. if not that is not so easy. Hint: remember that spline edges use mirror of last point for approxymation of y' in last point. |
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April 9, 2012, 03:10 |
blockmesh-flapping wing
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#20 |
Senior Member
kunar
Join Date: Nov 2011
Posts: 117
Rep Power: 15 |
Dear Slackware_user,
thanks for your reply first: these are the 3Dmodel coordinates generated in matlab,i have xyz coordinates of that model.for example generally people goes for cad model, same thing of that cad model but thing is i have coordinates, in matlab(that is model have 33 coumns and 225 rows xyz coordinates in .csv file format)how i can go for blockmesh. Thanks for the answer in advance! |
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