Flexible Scales Add to Speed of Shortfin Mako Shark
New York Times – Nov. 30
…Amy Lang, an aerospace engineer from the University of Alabama, and colleagues found that flexible scales around the side of the shark allow it to swiftly change direction while maintaining a high speed. She recently presented her work at the annual meeting of the American Physical Society’s Division of Fluid Dynamics in Long Beach, Calif. Working with biologists and with funds from the National Science Foundation, Dr. Lang studied dead shark specimens. Although the shark’s entire body is covered with the scales, made of the same hard enamel as its teeth, the scales on the top and underside of the body are larger and not as flexible. “The scales are about 0.2 millimeters in size on the mako’s sides,” Dr. Lang said. “And on the other species they can get much larger.” The tiny scales are flexible to an angle of 60 degrees or more, and allow the shark to control water flow separation across its body. Dr. Lang is now trying to create models of the shark scales in her laboratory, with hopes of finding real-life applications. “Flow separation is an issue in a lot of different engineering applications,” she said. “Some other person would take it from that point, but it could be used in the rotors of the helicopter blade, parts of a submarine or a torpedo.”