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General help for fvSchemes and fvSolution settings

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Old   March 3, 2009, 20:16
Default Hi, I am playing around wit
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Daniel Harlacher
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Hi,

I am playing around with OpenFoam for quite a while now but I still have my problems when it comes to choosing the "order" and "schemes" for those files.

In general I understand what every entry does and what the influence should be - but lately I ran in trouble with a perfectly working set of files and I could not figure out why.

My question would be if you have any general tips you can give me or even just paste a fvSchemes file you are using.

Right know I try to get a very good result for the drag of a sphere in low Re number area (50 - 200) so far I am using IcoFoam, but I am open for any suggestion to improve my current results.

My current fvSchemes:
http://harly.de.vu/www/sphere/fvSchemes
My current fvSolutions:
http://harly.de.vu/www/sphere/fvSolution

These files worked great for me for Re=200 and Re=150, but on the same mesh and lower Re (50,100) the Drag is too high.

Thanks a lot
- harly
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Old   March 4, 2009, 10:41
Default Hi Daniel, I would use back
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Jose Luis Santos
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Hi Daniel,

I would use backward or CrankNicholson for ddt, limitedLinearV for convection, and I would tighten the tolerance a little both on p and U.

Regards,
Jose Santos
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Old   March 4, 2009, 15:02
Default Thanks for the input I will ru
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Daniel Harlacher
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Thanks for the input I will run a simulation with these settings and will report back - other comments are very welcome.

- harly
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Old   March 4, 2009, 15:26
Default So, I am running now with t
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Daniel Harlacher
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So,

I am running now with the following modifications:

ddtSchemes
{
default CrankNicholson 0.5;
}

divSchemes
{
default none;
div(phi,U) Gauss limitedLinearV 1.0 phi;
}

p PCG
{
preconditioner DIC;
tolerance 1e-07;
relTol 0;
};

U PBiCG
{
preconditioner DILU;
tolerance 1e-06;
relTol 0;
};

I will report back when I have some results.
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Old   September 7, 2009, 10:31
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Marco Turchi
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Hi Daniel,
did you have a better results with the new settings?

Thank you
MT
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