Hi

I would like to hear from anyone who has had success in modelling a free surfaces using VOF (multiphase fluids) and at the same time be able to use a turbulence model. I have been able to get some good results by doing this. Has anybody else attempted this with any success.

thanks in advance eugenio

CFX 4 has free surface and VOF capability. Your local AEA office should have some good examples of this technology.

Hi, I was wondering if you could briefly explain something to me ? What is the difference (if any) between the CFX multi phase model and a volume of fluid method solver ? I have come across many papers that talk about VOF methods but never gone into any detail. Best regards Stuart

Multi-phase modeling models a transition from gas to liquid phase and cannot handle the sudden density change at a gas-fluid interface of differnt materials. That is where VOF is used.

Hi Pat, cheers for the reply. So is my understanding correct that CFX 4.3 already uses the VOF method for its multi phase modelling ? Also do you have any experience in the modelling of sloshing type problems ?

CFX 4 has free surface modelling for sloshing and spilling flows, but not a true VOF model. VOF is under development for CFX 5.

I have not used CFX 4 for free surface modelling.

Stuart Hi I have managed to model sloshing type problems using VOF in cfx.

The multiphase method it uses treats the two phases as a homogeneuous material (ie same equations for pressure , etc). It solves a different VOF equation for each phase although

cheers

eugenio

A bit late but I have seen a couple papers and thesis's using VOF with turbulence models(Not with CFX). Check out a paper by Peric (2000), also a PhD student from Karlsuhe I think his name was Sabisch,W (2000). Anyway, Its not uncommon now...

Vololololo

thanks for the tip would you please be able to provide me with more details to the paper by Peric and the Phd

thanks in advance

eugenio

Forschungszentrum Karlsruhe Wissenschaftliche Berichte FZKA 6478

Dreidimensionale numerische Simulation der Dynamik von aufsteigen Einzelblasen und Blasenschwaermen mit einer Volume-of-Fluid-Methode.

(Hope you like german)

For VOF on arbitrary meshes see: Ubbink, O. and Issa, R.I., 1999, A method of capturing sharp fluid interfaces on arbitrary meshes. J. Comput. Phys., Vol. 153, p. 26-50.