AlphaCourantNo code
 

Hi to all
I want to know how is calculated AlphaCourantNo so I look for the code and I find this lines.

if (mesh.nInternalFaces())
{
scalarField sumPhi
(
pos(alpha1 - 0.01)*pos(0.99 - alpha1)
*fvc::surfaceSum(mag(phi))().internalField()
);

alphaCoNum = 0.5*gMax(sumPhi/mesh.V().field())*runTime.deltaTValue();

}

My understanding of this piece of code is that for each cell it sums the face flux magnitudes, divides it by the cell volume and multiplies it with deltaT/2. The maximum over all cells is then the Courant number.
But I don't understand the meaning of this term:

pos(alpha1 - 0.01)*pos(0.99 - alpha1)

Anyone kwon the meaning of it?
Thank to all

I have the same question.Does anyone know the meaning?

Hi enzhen,
this line
gives you all cells where the volumetric phase fraction takes
values between 0.01 and 0.99.
And this piece of codeis the definition of the Courant number in multiple dimensions,
assuming that the calculated velocity field is divergence free.

So as a result, you obtain a Courant number in the interfacial area.

Hope this helps,

Best,
Daniel

thanks ~that does help