Average of the Navier’s Law on the Rapidly Oscillating Boundary

We study the flow of Newtonian fluid in a domain with periodically wrinkled boundary with slipŽNavier’s.boundary condition. The goal of this paper is to replace a microscopic boundary condition, posed on the rough boundary, by some macroscopic boundary condition, posed on the middle surface of the oscillating boundary. Depending on the shape of wrinkles and the friction coefficient we get four different effective models.