The similarities could result in 200-knot submarines that can turn on a dime. The secret lies in scales; not only do sharks have them, they “bristle” them:
"Hi, there."
… the scales actually reduce drag. And now researchers have discovered another special characteristic of shark skin. In light of evidence that some shark species may bristle their scales during fast swimming, engineers decided to see how lifting the scales on end affects water flow over the shark.
When scientists set up experiments to “mimic” the sharks, they noticed
… tiny vortices or whirlpools formed within the cavities between the scales. (The scales were raised at an angle of 90º to the surface of the skin.) The effect of these vortices was to form a kind of ‘buffer layer’ between the fast moving fluid and the skin’s surface, thus preventing a turbulent wake from forming behind the shark. In other words, reducing drag.
The same effect is produced by “dimpling” golf balls:
As a well-struck golf ball hurtles through the air, its dimples create mini vortices which reduce drag, just as the cavities formed on the surface of shark skin do when the scales are stood on end.
