Modeling gravity Flow inside an inclined pipe and simulate the hydraulic jump
 

Dear All,
I have just started to learn Flow-3D and I have an elementary background in CFD using Ansys Fluent doing some college projects. I want to model gravity flow inside main sewers. simulating hydraulic jump that occurs when there is a change in the slope. I have modeled the geometry in Solidworks and imported as .stl but applying the boundary conditions and physical model leads to divergence. can anybody help me establish a correct simulation?