how to set the free-surface BC in VOF method
 

Dear all,

I am working on the numerical wave tank by VOF method. I want to ask whether the free surface boundary condition should be imposed on the outer boundary, i.e., the top boundary of the whole domain, or just imposed on the interface of water and air. Furthermore, in the free surface boundary condition, the pressure is set to zero, and how about the velocity?

Thanks in advance!

jcn