[harly]

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

[santos]

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

[harly]

Thanks for the input I will run a simulation with these settings and will report back - other comments are very welcome.

- harly

[harly]

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.

[zebu83]

Hi Daniel,
did you have a better results with the new settings?

Thank you
MT