a flipperlike prototype is generating energy on Canada’s Prince Edward Island, with twin, bumpy-edged blades knifing through the air. And this summer, an industrial fan company plans to roll out its own whale-inspired model – moving the same amount of air with half the usual number of blades and thus a smaller, energy-saving motor.

Some scientists were sceptical at first, but the concept now has gotten support from independent researchers, most recently some Harvard engineers who wrote up their findings in the respected journal Physical Review Letters.
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when models of the bumpy flippers were tested in a wind tunnel, Fish and his colleagues found something interesting. The flippers could be tilted at a higher angle before stall occurred.

The scientific literature had scant reference to the flipper bumps, called tubercles. Fish reasoned that because the whale’s flippers remained effective at a high angle, the mammal was therefore able to manoeuvre in tight circles. In fact, this is how it traps its prey, surrounding smaller fish in a “net” of bubbles that they are unwilling to cross.

In 2004, along with engineers from the US Naval Academy and Duke University, Fish published hard data: Whereas a smooth-edged flipper stalled at less than 12 degrees, the bumpy, “scalloped” version did not stall until it was tilted more than 16 degrees – an increase of nearly 40 percent.

Fish then partnered with Canadian entrepreneur Stephen Dewar to start WhalePower, a Toronto-based company that licenses the technology to manufacturers.
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It has all been a bit of a culture shock for Fish, who is more at home in the open world of academia than the more secretive realm of inventions and patents. Two decades ago, his only motivation was to figure out what the bumps were for.

“I sort of found something that’s in plain sight,” he says. “You can look at something again and again, and then you’re seeing it differently.”