The key is thatThese scales control the separation of the flow of water around the bodies of the sharks. According to Amy Lang, a researcher at the University of Alabama (USA) who has presented the work at the annual meeting of the Division of Studies on Fluid Dynamics of the American Physical Society in California,? Flow separation is an issue of great relevance in systems and cases such as aircraft design, because it tends to create vortices that hinder stability and speed.?
? In nature, if we look at the surfaces of the skin of animals, we will see that they are not smooth. They present repetitive patterns. Why? A common application that has the presence of patterns on a surface is to control flows; Let’s think about the surface of a golf ball, thanks to which the ball can go further. We believe that the scales of sharks, which are capable of swimming very fast, serve a similar purpose ,? says Lang.
Lang and his team relied on experimental measurements and shark scale models to discover that the scale bases of short-finned or mako sharks (Isurus oxyrinchus) are narrower at the point where they meet the skin than at the top. This wedge-shaped silhouette makes it possible for the scales, called denticles, to be easily arranged at angles of 60 degrees or more, giving them the ability to move called “denticle bristling.” These flexible denticles are only present in the areas of the body where flow separation is most likely to occur, such as behind the gills.
“As we delve deeper into the investigation, we envision possibleapplications of flow separation control in the design of aircraft, helicopters, wind turbine turbines …any element for which the separation of the flow is relevant “, assures the researcher.
