 Porosity and permeability

 
This calc uses Darcy's law to give the permeability and porosity of a material for which suitable experimental characteristics are known. Viscosity for this purpose is the dynamic (i.e. not kinematic) viscosity).
 
Darcy's law is an approximation used extensively e.g. in earth sciences to determine the characteristics of a material. It models the flow of a liquid through a permeable medium. "Discharge" is the discharge rate and "residence" is the time it takes for a tracer to travel through the system (not required for the permeability calculation, which needs only the area, discharge rate, and residence time).  