[arash.mp]

Hi everyone and experts,
I want to model a pipe system (Using Ansys Fluent 16.0) that consists of a main pipeline and some porous layers around the main pipeline and i want to calculate the filtration velocity and some other things in the porous domain!
i want to know that what boundary condition should i use at the interface between the FREE FLOW and POROUS LAYERS?
the flow regime in the main pipeline is Laminar and i want to use "The brinkman Equation" in porous domain!
When i simply mark on the "porous Zone" in fluent and set the boundary condition between free flow and porous domain as "INTERIOR", the results are far away from the benchmark i have for the problem! i searched the web and found that there are special Boundary Conditions for this problem!
Should i use UDF or Something else for the boundary condition?And Also does Fluent Solve Brinkman equation in porous domain or i have to write a code for that ? i appreciate if someone can help me!

And another question is that the permeability of one of the porous layers is such that when i inverse that to calculate the Viscous Resistance, the value is more than 1e+20 which is the fluent limitation! how can i fix that?

thanks for your help and sorry for long question! i wanted to make everything clear.
thanks in advance.