[elos]

Hi I am trying to model multi-phase flow (air and water) using VOF

The geometry is rectangular box, inside box, another small rectangular (inlet)
The water is generated from the small rectangular inlet, and falls to the bottom side of big rectangular box (I gave the gravity option on), and bottom face is moving to right side in 0.015 mm/s.
What is the correct boundary condition for these four rectangular faces?

I tried it with right,left,upper side of big rectangular with pressure outlet (gauge pressure=0Pa), bottom side with moving wall. But the backflow at right side outlet is too high (more than 2 m/s which is much higher than the substrate velocity = 0.015 m/s)