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-   -   Outlet BC with Vof? (http://www.cfd-online.com/Forums/star-ccm/102247-outlet-bc-vof.html)

Januel May 26, 2012 05:24

Outlet BC with Vof?
 
Hello,

Question from a beginner:

I am running an analysis of a buoy with Vof and eulerian multiphase air/sea water. But what is the difference between the "Volum fraction air/sea water" and "Volume fraction Heavy/light fluid" boundary conditions? Manuals from CD-adapco suggest that "Heavy/light" fluid be used for velocity inlet and "air/sea water" for pressure outlet. When I use these settings it does not converge, but using "heavy/light" BC on outlet gives good convergence...

Running with 2DOF, z-translation and y-rotation (the latter rather large; <25 deg pitch-up).

Thanks!

Ladnam May 28, 2012 15:29

Heavy/light is the undisturbed volume fraction. Air/water is the resulting/disturbed volume fraction. So heavy/light should be used for BC.

Januel May 28, 2012 15:48

Thanks alot! Been wondering about that one and was unable to find an answer...


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