Laminar flow in a channel bounded by porous/rough walls: revisiting Beavers-Joseph-Saffman (Q6546158)

Getting grip of a macroscopic boundary condition able to describe reasonably the observable behavior of a fluid in contact with a porous interface has attracted already a lot of research, but it still keeps attracting many scientists. The general hope is to bring explainable modifications (in terms of microscopic information) of the so-called Beavers-Joseph-Saffman law, which is essentially an effective phenomenological object. The authors of this paper revisit this law for a simple geometry and fluid flow setting. They employ formal asymptotic arguments and numerical simulations to back up their statements.