Thanks for your answer!

To be shure that I understand it right, I have a few more questions to this topic. Where is the difference between the VOF reconstruction equation and the continuity equation?

The conservation equations will be solved implicit for every global time step (resulting from CFL = 2) and the VOF reconstruction equation will be solved explicit with a much smaler time-"sub-step" (CFL = 0.25). Am I right so far? Which of these equations will be solved first and how is it possible to solve the VOF equation without knowing the results of the conservation equations (e.g. velocity, ... ) for this (small) time step?

I understand that the Global Courant Number [variable Time Step Criteria] results from this equation: CFL = u*delta t / delta x, but could you explain how the Global Courant Number [Explicit VOF Criteria] is calculated in the console? I do not understand why this CFL number is sometimes much smaler then the variable-time-step-Criteria-CFL and after a number of time steps both CFL-numbers have the same value.

Thank you very much!