Designing structured surfaces that repel fluid-borne particles.

Using computational modeling, we examine particle-laden flows along surfaces decorated with periodic arrays of tilted posts. We show that when high-aspect-ratio posts are tilted against the flow direction, cross-stream circulatory secondary flows emerge. These circulatory flows enhance the net lift force acting on finite-sized particles transported by fluid, thereby repelling the particles from the wall and preventing their deposition. This hydrodynamic effect can potentially be used for designing antifouling and self-cleaning surfaces.