Mako sharks help make planes faster

One of the fastest sharks in the world, the Mako, is capable of underwater speeds of 74 km / h. She owes this opportunity to very short denticles on her scales. Recently, space technology engineer Amy Leung of the University of Alabama, USA, made a discovery that links the speed of mako and the structure of her skin.

All the teeth on the mako scales are directed from the head to the tail to minimize resistance to water flow. However, Leng found that on the most important parts of the shark's body, the teeth deflect up to 40 degrees relative to the body of the fish. She believes this is an evolutionary response to a phenomenon known as "split flow."

The negative effect of flow separation is observed in liquids and gases, when vortices are formed in the back of an object that is moving with acceleration through such a medium. They create resistance, prevent the medium from evenly flowing around the moving body, but in the case of mako sharks, the protruding teeth neutralize this effect. Due to the strategic location of such areas of the scales, the negative impact disappears along the entire length of the shark's body.

Leng's team set up an experiment in a tunnel with a benchmark for split flow on a smooth surface. The test piece was then replaced with rough mako shark skin and re-measured. In all cases with shark skin, the magnitude of the resistance decreased significantly, which confirmed the guesses of the scientists. Now they are going to create an artificial analogue of such a surface - and in the future, new coatings for aircraft wings, helicopter blades, and submarine hulls.