[cby0112]

I am conducting a simulation of river confluence with a sloped inlet where the main stream inlet is not perpendicular to the mesh boundary and forms an angle. Given the main stream flow rate but unknown inlet velocity, how can I set boundary conditions to allow water to flow diagonally into the main stream inlet?

[iqbalikromi]

Hi, I think you need to simulate the case (only upstream) using 2D to know the velocity magnitude, then you can use the result to feed in your 3d model boundary condition.

[cby0112]

Thank you very much for your answer. I also want to know how to make the flow rate flow obliquely into the tributary when setting the flow rate, just in the direction of the red arrow in the sketch.