My geometry is a prototype of a hydroelectric plant. It consists of a tank, penstock, a gate and a test section; my aim is to simulate turbulent flows on this prototype with Ansys Fluent. My geometry consists of two zones, a zone filled with water (red color) and a zone filled with air (blue color). The water will start to flow when I pull the gate to the top (unsteady state). At first, I want to know what boundary conditions I should give to this geometry and what boundary conditions I should give to the gate. Do I have to use a dynamic mesh to give a motion to this gate and which UFD example should I use?

Secondly, can I consider this geometry as an open channel? If yes, how I can determine the free surface level and the bottom level at outlet?

Sorry for my English.

Can you help me please??? Thanks