Recommended Boundary Conditions?
 

Hello!

So I am running a case using a solver that I customized, and I have more of general question for those that may understand more about stable boundary condition implementations.

So, in my simulation I am looking at a channel that is under an applied hydraulic pressure, and I know the incoming velocity. Except I know that it is not a good idea to specify fixed value BCs for velocity and pressure at the inlet. So then I wanted to set the pressure at the outlet, but I also realized this is unstable, as the only value of pressure you should fix at an outlet is static pressure. And I have no idea what the velocity would be at the outlet, as water is permeating into the channel along its length.

So, any recommendations on how to specify the BCs?
Thank you so much in advance.