Difference between revisions of "Benchmark ercoftac ufr2-02"
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== Description == | == Description == | ||
For a full description of the case see:<br> | For a full description of the case see:<br> | ||
| − | http://qnet-ercoftac.cfms.org.uk/index.php?title=Flow_past_cylinder | + | http://qnet-ercoftac.cfms.org.uk/index.php?title=Flow_past_cylinder <br> |
| + | or <br> | ||
| + | [http://cfd.mace.manchester.ac.uk/cgi-bin/cfddb/prpage.cgi?43&EXP&database/cases/case43/Case_data&database/cases/case43&cas43_head.html&cas43_desc.html&cas43_meth.html&cas43_data.html&cas43_refs.html&cas43_rsol.html&1&0&0&0&0 here] | ||
U_in = 0.54 m/s with 2% turbulence<br> | U_in = 0.54 m/s with 2% turbulence<br> | ||
| Line 13: | Line 15: | ||
== Results == | == Results == | ||
| − | Experimental | + | '''Experimental results'''<br> |
The Strouhal number is around 0.132<br> | The Strouhal number is around 0.132<br> | ||
Drag coefficient is around 1.9-2.2<br> | Drag coefficient is around 1.9-2.2<br> | ||
| − | + | '''OpenFOAM results'''<br> | |
| + | The grid here, and in the supplied example, is too coarse really. But it's nice for testing different setups before doing the ''real'' simulation<br> | ||
| + | and its good enough to be used for mapping if you want to run on a fine mesh without the initial start-up.<br> | ||
[[File:urf2-02-Cd.png | 300px | OpenFOAM Cd results ]] [[File:urf2-02-Cl.png | 300px | OpenFOAM Cl results ]]<br> | [[File:urf2-02-Cd.png | 300px | OpenFOAM Cd results ]] [[File:urf2-02-Cl.png | 300px | OpenFOAM Cl results ]]<br> | ||
| − | The drag coefficient fluctuates a bit but after 5-6 seconds the average settles around | + | The drag coefficient fluctuates a bit, but after 5-6 seconds the average settles around 2.04.<br> |
| − | The calculated Strouhal value in the above picture is | + | The calculated Strouhal value in the above picture is around 0.135.<br> |
| + | <math> | ||
| + | St = \omega \frac{D}{U} = \frac{D}{\tau U} | ||
| + | </math> | ||
== Notes == | == Notes == | ||
| Line 40: | Line 47: | ||
== Download == | == Download == | ||
| − | The application to use is | + | The application to use is '''pimpleFoam''' and the case can be downloaded [http://openfoam.nequam.se/cases/ufr2-02.tgz here ] |
== References == | == References == | ||
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* http://www.tfd.chalmers.se/~lada/postscript_files/ahmad_ASME-JSME_paper.pdf | * http://www.tfd.chalmers.se/~lada/postscript_files/ahmad_ASME-JSME_paper.pdf | ||
| − | It is just a small list that is by no means complete.<br> | + | It is just a small list that is by no means complete, since I dont want to copy it from the ercoftac database.<br> |
--[[User:Niklas|Niklas]] 13:29, 24 April 2010 (UTC) | --[[User:Niklas|Niklas]] 13:29, 24 April 2010 (UTC) | ||
Latest revision as of 12:30, 22 July 2011
Contents
1 ERCOFTAC UFR 2-02: Flow past a square cylinder
1.1 Description
For a full description of the case see:
http://qnet-ercoftac.cfms.org.uk/index.php?title=Flow_past_cylinder
or
here
U_in = 0.54 m/s with 2% turbulence
Re_D = 22 000
Size of the square cylinder is 0.04 m wide and 0.392 m high.
Its situated in a tunnel with a width of 14D = 0.56 m.
1.2 Results
Experimental results
The Strouhal number is around 0.132
Drag coefficient is around 1.9-2.2
OpenFOAM results
The grid here, and in the supplied example, is too coarse really. But it's nice for testing different setups before doing the real simulation
and its good enough to be used for mapping if you want to run on a fine mesh without the initial start-up.
The drag coefficient fluctuates a bit, but after 5-6 seconds the average settles around 2.04.
The calculated Strouhal value in the above picture is around 0.135.
1.3 Notes
In the case directory there is a perl script called generateMeshDict.pl.
This script will generate the blockMeshDict file given input arguments. To see what they are just run it without any input arguments and
it will write some helpful usage info.
If you want to run a 2D simulation just edit the generateMeshDict.pl and remove the comment infront of $nz.
my $nz = int(0.2*$H1/$dx) + 1; #$nz = 1;
and change the wall bc to empty for lowerUpper patches
print " wall lowerUpper\n";
1.4 Download
The application to use is pimpleFoam and the case can be downloaded here
1.5 References
This list only contains references that can be obtained for free and that are not subject to any copyright infringement...I hope.
- http://www.tfd.chalmers.se/~lada/postscript_files/ahmad_corsica.pdf
- http://www.tfd.chalmers.se/~lada/postscript_files/ahmad_ASME-JSME_paper.pdf
It is just a small list that is by no means complete, since I dont want to copy it from the ercoftac database.
--Niklas 13:29, 24 April 2010 (UTC)
