Whale Power: Seeking More Efficient Blades
The bumps on a humpback whale’s flipper, seen here in a mating ritual, are on the “wrong” side. Physicists are familiar with bumps on the trailing edges of wings or fins, but here they are found on the leading edge.
That led Dr. Frank E. Fish, a biologist at West Chester University of Pennsylvania, to try to design a fan blade that moved air as efficiently as a whale’s flippers move the animal through water. The result was WhalePower, a Toronto-based company that designs blades for fans, turbines, and more, inspired by a whale’s bumps.
On a whale, the bumps help it move effortlessly through the water at much steeper angles than it would otherwise. A Harvard study found that the angle of attack (the angle between the flipper and the direction of water flow) of a humpback whale flipper can be up to 40 percent steeper than a smooth flipper, giving the whale more control.
WhalePower’s product is “the first time, other than in whales and some fossilized fish, that this has been done,” said WhalePower Vice President of Operations Stephen Dewar. “Everyone knew” that a blade’s leading edge should be smooth to facilitate air flow, but the humpback whale proved everyone wrong.
“I did nature documentaries at one point in my career,” Dewar added. “And I asked, ‘What are the bumps on humpback whales for?’ [The response was] ‘Oh, they’re just barnacles.’ They weren’t.”
Currently, the technology is appearing in industrial fans for warehouses, where WhalePower fans move 25 percent more air than conventional fans while using 20 percent less energy, but WhalePower hopes to retrofit wind turbines with these bumps to increase energy output by 20 percent and reduce the noise associated with large turbines.