scaled model of fluid tube

[ozalzi]

Hi,
Im working on a CFD 3D model of laminar fluid flow along tube with ADINA 9.4.

There is a portion of the tube that i want to model as porous medium in order to mimic the flow resistance of a longer tube, i.e.:
1 meter of laminar flow inside rigid tube will be scaled down to 10 centimeter of porous media.

The parameters requested by the ADINA that i have trouble to properly calculate are the porosity and permeability of the material.

any ideas? other solution methods may help too.
thanks,
Oren