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Bruce July 18, 2007 01:52

Free surface modeling

I m working on modeling the free surface of fluid(water) in an agitated vessel. the vessel uses a disc impeller.

I've created the geometry and meshed it as well...

I want to use VOF to model the interface(between air and water)..But when applying the boundary condition there seems to be no provision for this sort of specification!!

i need some help in this regard..

thanks, Bruce

Gert-Jan July 18, 2007 06:44

Re: Free surface modeling
Where do want to apply a BC and what do you want to specify?


Robin July 18, 2007 15:16

Re: Free surface modeling
Hi Bruce,

You must first pick two fluids in your domain and set the appropriate multiphase options. I suggest going through the free surface flow over a bump tutorial first, this should give you a clear idea of how to proceed.

Regards, Robin

Bruce July 19, 2007 12:47

Re: Free surface modeling

Thanks for the response..

Actually,i have 2 domains in my system. the bottom one is the water that is being agitated by the disc impeller.The one on top consists of air.both the domains are cylindrical. the two domains are connected by a domain interface....I have sufficiently inflated the domain interface on either side.

Now,for this domain interface i want to use the VOF model..and the VOF model requires a multiphase option..!

i am wondering if i can bring the multiphase option into picture for the domain interface alone..

hope I have made myself clear..

@ RObinm

I am currently going thru free surafce over bump..!!

THanks..and regards, BRUCE

Robin July 19, 2007 15:00

Re: Free surface modeling
HI Bruce,

I think you have misunderstood what domain interfaces and multiphase free surfaces are. A domain interface simply allows you to connect dissimilar meshes at a surface (not necessarily in separate domains). It does not allow you to specify where the air-water interface exists. The air-water interface is dynamically calculated by the solver.

A multi-phase license is not required for free surface calculations if you are using the homogeneous multiphase model.

Regards, Robin

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