Derivation of Stokes-plate-equations modeling fluid flow interaction with thin porous elastic layers
Markus Gahn, Willi Jäger, Maria Neuss‐Radu
Abstract
In this paper we investigate the interaction of fluid flow with a thin porous elastic layer. We consider two fluid-filled bulk domains which are separated by a thin periodically perforated layer consisting of a fluid and an elastic solid part. Thickness and periodicity of the layer are of order ϵ, where ϵ is small compared to the size of the bulk domains. The fluid flow is described by an instationary Stokes equation and the solid via linear elasticity. The main contribution of this paper is the rigorous homogenization of the porous structure in the layer and the reduction of the layer to an interface Σ in the limit ϵ→0 using two-scale convergence. The effective model consists of the Stokes equation coupled to a time-dependent plate equation on the interface Σ including homogenized elasticity coefficients carrying information about the micro structure of the layer. In the zeroth-order approximation we obtain continuity of the velocities at the interface, where only a vertical movement occurs and the tangential components vanish. The tangential movement in the solid is of order ϵ and given as a Kirchhoff-Love displacement. Additionally, we derive higher-order correctors for the fluid in the thin layer.