  In this paper, we study the effects of both the amount of open cell walls and
their aperture sizes on solid foams permeability. FEM flow simulations are
performed at both pore and macroscopic scales. For foams with fully
interconnected pores, we obtain a robust power-law relationship between
permeability and membrane aperture size. This result owns to the local pressure
drop mechanism through the membrane aperture as described by Sampson for fluid
flow through a circular orifice in a thin plate. Based on this local law,
pore-network simulation of simple flow is used and is shown to reproduce
successfully FEM results. This low computational cost method allowed to study
in detail the effects of the open wall amount on percolation, percolating
porosity and permeability. A model of effective permeability is proposed and
shows ability to reproduce the results of network simulations. Finally, an
experimental validation of the theoretical model on well controlled solid foam
is presented.
