I am trying to run flow simulation for a model pump generator that pumps 300 GPM of water. My main problem is that I cant choose the same face for two boundary conditions, but I can't. I need to specify the outlet flow rate of 300 GPM and also give an environment pressure (since a pressure opening condition needs to present in every simulation). I have also given an inlet velocity of 0.5 ft/s to the surrounding walls that simulate a river.
How else can you define the boundary conditions to get around this problem? I need to specify an outlet volume flow on the outlet face, but where can I specify the pressure opening?