We study the flow of Newtonian fluid in a domain with periodically wrinkled
boundary with slip (Navier's) boundary condition. The goal of this paper i
s 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. (C) 2001 Academic Press
.