[gcoopermax]

I want to model a submerged sea strainer. The strainer has several slots and resides near the sea bed at the bottom or riser pipe that runs to the vessel on the sea surface as shown below (apologies for poor drawing ):


Strainer is about 650mm in diameter and 2 meter in height.
How do I specify inlet for this? I can see two options:
1) Applying volume flow rate on all surfaces of the slots. However since thickness of the strainer (and hence length of the inlets in our case) will be small (of the order of 10 mm for a 20mm wide slot).
2) Modelling a sphere around it and specifying inlet at its surface such that water works enters the strainer through slots. A bit more elegant than #1 but enforces the direction of inlet velocities to the centre of sphere, may not be strictly physical.

I can't represent the surface as porous zone as the shape of the slots are fairly large so assumption of periodic slots may not be strictly correct.

[Gert-Jan]

Why don't you put the outlet in the vertical pipe of the strainer and set the total volume flow there? And then set a pressure on a large sphere (or even better a cilinder) around the strainer?

[gcoopermax]

Tried that, it diverged. That said, even if it had converged, what's the benefit? The modelling of inlet geometry would still need to be decided

[Gert-Jan]

You should set total pressure (Stable) on the inlet with direction normal to boundary. Should work.