VOF method for liquid metal
 

Dear CFD people,
as a part of my master thesis I have to model the following problem in CFX:
in a "closed box" exists two liquid metals with different densities. I have to model the interface of the liquids under a finite body force.
I am using VOF with "free surface" to solve for the interface but I don't get a good answer!
can anybody help me and give some hints how to solve such an easy!! problem??

Thanks

Here's my first hint:
http://www.cfd-online.com/Wiki/Ansys...ible_answer.3F

And here's a second hint:
http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F