I am trying to simulate pipe flow through a 5” Sch 10 pipe running vertically about ~14 feet as shown in attachments. I would like to first benchmark my Flow Simulation model against the same model in BOSFluids. For a delta P of 2psi I expect to get an average flowrate of ~22 ft^3/s and an average velocity ~144 ft/s. When I apply a boundary condition of 5 psi at the inlet surface and 3 psi at the outlet surface in Flow Simulation I get a an average velocity ~1000 ft/s. Conversely, if I apply a flowrate of 22 ft^3/s at the inlet and 3psi at the outlet, the velocity is close to 144 ft/s but the delta P between the outlet and inlet surfaces is ~0.01 psi. Can someone help with what I could be doing wrong with my Flow Simulation model? My mesh is set at level 5 with ‘minimum gap size’ equal to 0.5*inside pipe radius and ‘minimum wall thickness’ equal to 0.5*pipe wall thickness with narrow channel refinement checked. Goals are selected for Av Velocity, Av Static and Av Total Pressure.

Just to verify, you do have gravity turned on and in the correct direction?