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-   -   Flow around a cylinder Vortex Shedding ForceCoeffs (http://www.cfd-online.com/Forums/openfoam-solving/58396-flow-around-cylinder-vortex-shedding-forcecoeffs.html)

harly November 2, 2008 21:11

Hi, I am currently getting
 
Hi,

I am currently getting familiar with OpenFOAM-1.5 and I am trying to create a Cl/Cd plot for a cylinder. I have got a paper to compare my results to and I am having a hard time getting to a proper Result.

I am using Icofoam for a round cylinder and Re=105. There is vortex shedding but the coefficients don't match - they are to high almost twice the Cd.

I played around a lot and the fact, that the same Case with the same Re - number can produce different results on how I choose U and nu was very confusing.

I will upload my files this night and post the links.

Until then I really would like to know if some of you have successfully compared OpenFOAM Coefficients with a paper or an other solver like fluent/cfx using air and what your configuration were for nu.

I would love to summarize every input after we solved this Problem so everyone can profit from it.

yours
harly

harly November 3, 2008 01:50

Here are the links to my files
 
Here are the links to my files. In this case I used U = 1 and defined nu to fit the Re = 105.

It works pretty well except I cannot evaluate the results - so I want to run the same case with air but when I change the velocity and nu to air I am not getting a proper vortex shedding.

My files:

http://home.arcor.de/daniel.harlacher/www/U
http://home.arcor.de/daniel.harlacher/www/p
http://home.arcor.de/daniel.harlacher/www/controlDict_1
http://home.arcor.de/daniel.harlacher/www/fvSolution
http://home.arcor.de/daniel.harlacher/www/fvSchemes
http://home.arcor.de/daniel.harlache...rtProperties_1

what do I have to change if I want to use air ? (I thought only U and nu, but that didn't work that well...)

Thanks for every suggestion


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