Forced flow through a channel with longitudinal strips

Fluid is forced through a channel obstructed by periodic thin longitudinal strips. The viscous flow equations are solved analytically through domain decomposition and eigenfunction expansions. The flow rates for different spacings are determined. For widely separated strips, the drag on a single strip in a channel can be extrapolated. If the strips are closely spaced, the obstructions represent a simple porous media. Using the analytic solution, we find the empirical Beavers–Joseph condition cannot be valid for this particular geometry.