CFD Online Discussion Forums - Calculate 3D bubble volume in twoPhaseEulerFoam in OF23x

Quick answer: I'll quote part of a recent PM you sent me:

Quote:

Originally Posted by Gitesh P

Somehow I need to calculate bubble volume in certain box. To calculate bubble volume in defined box I need to integrate volume fraction and cell volumes there. And I need that information at each iteration. Could you suggest something how I can do that in OpenFOAM?

I have already extracted many data via sampling during run. But for bubble volume data requires also the cell volumes in defined box and I have tried to find it via Google but no any success yet.

You've already got part of the idea correctly. The simplest way of calculating the total volume of bubbles is to rely on the alpha field and to multiply by the volumes of the cells... which you can do by using the integration operation. I know that's explained somewhere on the forum... if I'm not mistaken, this can help: http://www.cfd-online.com/Forums/ope...tml#post388158 - start reading from post #7 and onwards.

As for calculating only in a particular region, this thread has part of the idea you need: http://www.cfd-online.com/Forums/ope...ume-field.html - using topoSet can be used either after the simulation is already done, because you can do several cell/face/point selection operations, as described in the main "topoSetDict" example: https://github.com/OpenFOAM/OpenFOAM...et/topoSetDict - namely in the location given by this command:

Code:

echo $FOAM_UTILITIES/mesh/manipulation/topoSet/topoSetDict

As for the other part, namely to do the calculation for a part of the mesh... I can't remember exactly how it's definable, it at all... but I vaguely remember seeing something about it for swak4Foam... I don't know if the library "swakTopoSources" has what you need... have a look at the tutorial mentioned here: https://openfoamwiki.net/index.php/C...uctImplicit.3D
In addition, check in the main page: https://openfoamwiki.net/index.php/Contrib/swak4Foam - for the sections "FAQ", "Further information" and "Examples"