[K.C.]

Dear Foam-User,

I am facing a problem that might be treated as multiphase-flow or maybe not. I want to simulate the segregation of two gases due to gravitational effects. For example, Helium and N2 are inserted to my domain in a mixed state (mass fraction both 0,5) but the domain is large and the lighter Helium should accumulate at the top. Which solver should I use for that?

I have seen the solver interFoam, the typical multiphase solver, but this solver only seems useful for flows with a clear interface between two immiscible fluids.

In addition, I have looked at buoyantReactingFoam in OpenFoam10. It looks like he can handle miscible gases, but all mass fractions Yi are transported with the same velocity field. So, there will never be a separation of lighter Helium and heavier N2.

The only solver class that uses a different velocity field for each component is a Euler-Euler type solver like twoPhaseEulerFoam. But these solvers are designed for dispersed flows. How could I define a phase interaction parameter between two phases that are perfectly miscible? Does anybody have an idea for modelling these parameters?

Thanks in advance for any reply,
K.C.