[kraf]

Hello! A beginner in OpenFOAM.
I want to simulate a inclined open channel using Pisofoam. I want different values for discharge with different slopes. I noticed in the tutorials that only U and P are specified as boundary conditions. In the tutorials the bed is flat so I wonder, what causes the movement of flow from the inlet to the outlet in that case.
Also, what type of velocity should I set in the inlet BC? Is it the depth averaged velocity? Is this velocity at the boundary changing with time or is constant until the end of the simulation.
Thank you for your help in advance!
(I'm using pisofoam because I want to simulate turbulent flow as final objective)