In electronic cooling and HVAC it is common to define a porous region to simplify complex geometry such as ventilation grills and wires amongst other things. This is easy to approximate using the free air ratio based upon know geometry. It is more complex to translate this to the currently supported models. It could be implemented that the coefficients are calculated based upon the free air ratio, to get loss coefficients and then to darcy’s coefficients f and D. This would reduce setup time, and the depth of understanding required to get to the coefficients from simple geometry.
Cheers,
Darren