Reply To: water inlet height-(water inlet boundary)-dose it represent a fixed height?

[Rob]

Open channel, you need to set that in both the Multiphase VOF panel and the inlet boundary condition panel. Be careful with position and depth settings to ensure you define these correctly. Note, I'd advise against a zero area inlet and start with some water entering the domain. Also read up on the VOF model as you're going to need a lot of mesh to resolve the flow and free surface.