[Zukkattack]

Hello to everyone, first time posting here. I am looking for help because I can't find a way to set the fan boundary condition for my 2D simulation.

The domain is a channel between two zones, all filled with water. I would like to insert a fan boundary condition to set a pressure change in the middle section of the channel, in order of course to simulate the presence of a fan there (see picture).

The problem is that when I go to Fluent to set the boundary condition for that line, the fan boundary condition is not shown, the most similar things I have are "intake fan" and "exhaust fan". If I try with one of them, they act like a wall not letting water flow through.

What am I doing wrong? I hope my explanation was clear, for any clarification, just ask.

[LuckyTran]

Can you change that boundary type to interior? If not, then it's a boundary and not a collection of interior cells and that's why you cannot set it to a fan.

[Zukkattack]

Originally Posted by LuckyTran

Can you change that boundary type to interior? If not, then it's a boundary and not a collection of interior cells and that's why you cannot set it to a fan.

Thanks for the answer. No I can't change it to interior, and yes I designed it as a line, not a collection of cells. How can I do that?

[Zukkattack]

UPDATE: I tried to create a named selection of interior cells instead of using a boundary, but now this named selection does not even appear in the list of the boundary conditions of FLUENT (see pictures). What am I doing wrong?

UPDATE 2: I also found this on the Help page: "Since the fan is considered to be infinitely thin, it must be modeled as the interface between cells, rather than a cell zone. Thus the fan zone is a type of internal face zone (where the faces are line segments in 2D or triangles/quadrilaterals in 3D)."

At this point I understood that I should select the interface between cells and not the cells. But if I do that, the boundary condition that I obtain in FLUENT is not an "interior" one, but a "boundary" one.