Shark skin surface for fluid-drag reduction in turbulent flow

Abstract

Nature has created ways of reducing drag in fluid flow, evident in the efficient movement of fish, dolphins, and sharks. The mucus secreted by fish reduces drag as they move through water, protects the fish from abrasion by making the fish slide across objects rather than scrape, and prevents disease by making the surface of the fish difficult for microscopic organisms to adhere to, minimizing biofouling (Shephard in Rev Fish Biol Fish 4:401–429, 1994). Applications of drag reducing polymers has been long known.