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-   -   interFoam and alphaEqn.H (http://www.cfd-online.com/Forums/openfoam-programming-development/100397-interfoam-alphaeqn-h.html)

pablodecastillo April 25, 2012 05:50

interFoam and alphaEqn.H
 
Hello,

Why in alphaEqn.H is it not added alpha1 = max(min(alpha1, scalar(1)), scalar(0)); i mean this artificial bounded?

Thanks

Phicau April 25, 2012 06:55

Hi

MULES solver ensures boundedness, that is why the last 2 inputs are 0 and 1, the bounds of alpha1. This is achieved by the use of limiters.

The final result may show values greater than 1 or lower than 0, but with differences of the order of 10^-5, which is negligible.

Regards

santiagomarquezd May 1, 2012 09:52

Using an artificial bounding of this kinds leads to a non-phase-preserving algorithm due it 'cuts' with having in account the conservative properties of the alpha equation. In other words you will lose or gain mass.

Regards.

pablodecastillo May 7, 2012 14:57

But looking for steady state loss or gain mass is not going to be relevant or yes?

Thanks

santiagomarquezd May 8, 2012 13:59

Hhmm, I don't know, but since the solver is unsteady probably it will blow up before reach the steady state due mass preservation problems.

Regards.


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