Boundary conditions at fluid-permeable interfaces in porous media: A variational approach

A general set of boundary conditions at fluid-permeable interfaces between dissimilar fluid-filled porous matrices is established starting from an extended Hamilton–Rayleigh principle. These conditions do include friction and inertial effects. Once linearized, they encompass boundary conditions relative to volume Darcy–Brinkman and to surface Saffman–Beavers–Joseph dissipation effects.