Waves again %-(
 

Hi there.
From the beginning. I am using F3D 9.3.1. I tried to test wave tank from training course, user site example, and forum example. So the point is that water flows away and the volume of fluid decreases. It happens when wave with initial amplitude comes to right border.
Could anyone explain me what am I doing wrong.

I assume you use the outflow boundary condition at the downstream and check the box for outflow boundary condition dialog. You may try using split lagrangian VOF method under the Numerics tab.

Dear H.C.

You are absolutely right. I am using outflow BC with "allow fluid..." and water level and Split Lagrangian VOF.
Of course I can use long tank for modeling but this is bad decision.