[saeedi]

Hi,

I recently started using OpenFoam. I want to learn how we can prescribe a profile at the inlet boundary of the domain?

Or, if needed, can we have time dependent pre-generated data (from a precursor simulation) and feed them to the inlet at different times?


Thanks a lot for your help.

[Svensen]

For the time variation of the inlet you can use the following form:

uniformValue     tableFile;       
tableFileCoeffs       
{       
    fileName     "$FOAM_CASE/myDataFile"       
    outOfBounds  clamp;       
}

it is written more detailed here: http://www.openfoam.org/version2.1.0...conditions.php

For generating a parabolic profile you can use groovyBC library. The information and a short example of creating such profile are presented here: http://openfoamwiki.net/index.php/Contrib_groovyBC

[saeedi]

Thank you very much for your reply.

Also, In the simpler case that I want to just prescribe a profile, can I just prescribe a table and ask it to read it and use it during the entire simulation?

[Svensen]

you need to study a documentation of the groovyBC library. I never used this library in my practice... Maybe someone else could help you

[saeedi]

Hi Svensen,

Following our previous conversation on BC, I now need to apply an inlet BC that uses data from a table. Could you please give me some detailed explanation if you have done it before.

The webpage you mentioned does not say anything more that what you already posted which is :

uniformValue tableFile;
tableFileCoeffs
{
fileName "$FOAM_CASE/myDataFile"
outOfBounds clamp;
}

I basically want to know:

What should be the format of that table (should it have two columns like Y and U or any thing else)?

Does it have to have the exact same number of rows as the number of grid points in the vertical direction or not and it can do the interpolation?

Any other useful tip?

Thanks a lot

[Svensen]

A file content looks like the following:
(
(0 (0 0 0.205969))
(0.001 (0 0 0.206249))
(0.002 (0 0 0.206554))
(0.003 (0 0 0.206883))
...
);

So, you first put the time value, then three component of velocity.
In a "classical" OpenFOAM this file specifies the same velocity in all points of your patch. For example, all points of patch will have a velocity vector (0 0 0.205969) at the t=0.