GlobalPost, Feb. 4, 2012
BERLIN, Germany — The connection between humpback whales and helicopters might not seem obvious. But a group of researchers in Germany are thinking way outside-the-box, applying nature’s design to helicopters to make them faster and more maneuverable.
The team at the German Aerospace Center (DLR), in Goettingen, was eager to solve an aerodynamic conundrum: The airflow over a helicopter’s main rotor blade creates a hazard called “dynamic stall.” This causes turbulence, a loss of lift, and exerts extreme pressure on the rotors, ultimately limiting maneuverability and the speed that any helicopter can reach.
When searching for a way to thwart this stalling, they hit upon the humpback whales. The marine mammal’s speed and acrobatic prowess is largely attributed to its large pectoral fins, which have characteristic bumps along the front edge. These bumps, it turns out, significantly delay such stalling.
“This particular shape makes the humpback whale more agile,” Kai Richter, a researcher the DLR Institute of Aerodynamics and Flow Technology, told GlobalPost. Continue reading