[sek]

I'm running rasInterFoam on a free-surface problem. The tutorial says "the free-surface treatment in OpenFOAM does not account for the effects of turbulence...". Can someone who's familiar with the innerworking of FOAM please explain what this means?

[hjasak]

It means it is using a single-phase turbulence model with no corrections for the density ratio or presence of free surface.

Hrv

[sek]

I see. Thanks, Hrv. Yet, the same paragraph of the tutorial (U-61, Chapter 2.3) continues "... as a consequence, all free surface somulations can be viewed as a direct numerical simulation of fluid flow...". I surmise this is not true. Even with a single-phase turbulence model, turbulent viscosity near free-surface would be much larger than molecular viscosity. And it is not going to be anything close to DNS. I would just take he entire paragraph as trying to remind us of the inherent limitations of the simple mixture-based turbulence model - it won't be able to describe complex turbulence physics near free-surface.

[msang]

Hi,

I am searching for a way (hopefully simple) to correct the k-epsilon turbulence model in rasInterFoam for the effects of density ratio and free surface. I am mostly interested in the water phase, although this may not simplify the anything. Does anyone have suggestions for a reasonable staring point, references or a solver?

Thanks

Mark

[onurdundar]

Hi Mark
I am interesting in the same concept. I found a paper has a simple approach to the solution of turbulence near the interface for k epsilon turbulence model.

onur