Simple mathematical models with two time constants are used to study the dy
namics of pressure variation during permeability measurements on, dual poro
sity saturated media. We think that these transient phase dynamic aspects,
which Darcy's Law cannot explain, are a macroscopic image of flows in macro
and micropores. (C) 1999 Academie des sciences/Editions scientifiques et m
edicales Elsevier SAS.