visualize free-surface, VOF
 

In star-ccm+ they suggest VOF=0.5 to visualize the free surface for immiscible fluids :eek:. How about other codes (Fluent, Flow3D, CFX, Tidal, OpenFoam, etc) ? Is the same VOF=0.5 chosen to represent the free-surface? What does VOF=0.5 mean? Isn't it a surface where it is 50% air and 50% water? :confused:

It is an interpolation. 50% means that the cell has 50% water and 50% air so the free surface is located in the middle.

I think considering vof=0.5 is the normal thing to do.