[paul]

What is the alpha variable in the settlingFoam solver. I thought alpha was the solids fraction, but the settling tutorial uses a value of 0.001. This seems to be a very low number for the solids fraction.

[pbohorquez]

Hi Paul,

You are right - 'alpha' is the volumetric fraction of particle in the particle-fluid mixture. You can read the thesis by Daniel Brennan (2001) for further details: Section 6.4-6.6 corresponds with the Dahl tutorial, while Chapter 7 deals with the tank3D case.

Please, take into account that although the initial suspended load is really low, as time goes by the settled sludge layer raises (where the volumetric fraction reaches the maximum packing factor).

Patricio.