W. G. Pritchard Lab Seminar: 4:30-5:30 PM, 101 Osmond Laboratory ### NOTE special time ### **Tuesday December 2, 2003** Stokes flow in curvilinear channels - an analytical approach Vladimir Mityushev Department of Mathematics Pedagogical University Slupsk, POLAND Abstract: We consider Stokes flow through a three-dimensional curvilinear channel. The surface of the walls is described by functions whose amplitudes are proportional to a dimensionless parameter epsilon. The application of an analytical-numerical algorithm yields efficient formulas for the velocities of the fluid and the permeability of the channel; these formulas include epsilon in a symbolic form. When epsilon increases, the Poiseuille flow (epsilon=0) is disturbed, and eddies arise above a critical value of epsilon. These results are generalized to the stationary Navier-Stokes equations. A similar analytical-numerical method is applied to diffusion on rough periodic surfaces. The macroscopic diffusion tensor is determined by averaging the local flux over the representative cell. The relation between stationary diffusion on surfaces and two-dimensional non- homogeneous materials is also discussed. ### NOTE special time ###