[atylamatheus]

Good morning everyone, I would like help with this simulation. I am sending the attached image.
There are two concentric cylinders, between them there is a fluid (oil) and this interior has porosity and permeability. In the smaller cylinder there is an entry condition where a fluid (water) will enter. In the upper and lower parts a stationary wall condition is defined. In addition, in the outer (larger) cylinder, a pressure condition from the outside to the inside of the cylinder is defined.

My question is how to define in FLUENT that there is a fluid entering and another fluid residing between the two cylinders.
Also, I'm not sure how to define porosity and permeability inside.

Please could someone help me?