More lessons from nature

Smooth isn't always best.

Whales and dolphins were molded by evolution to glide through water. We've been trying to create streamlined designs ourselves for structures such as wind turbine blades. Now researchers are examining the flippers, fins and tails of our water-dwelling cousins to learn how to improve engineering designs. Dr. Frank Fish—yes, that's really his name—from West ChesterUniversity in Pennsylvania presented this research July 8 at the Society for Experimental Biology's annual meeting in Marseille.

Here's one example of the way Dr. Fish's research is being applied. Whale flippers have a bumpy edge. This makes little sense to engineers. They've designed structures like wings and blades that ensure a steady air flow. But it turns out the unsteady flow over this more complex shape increased lift and reduces drag much better than any previous manmade design. It has to do with something called vortices. These are small tornado-shaped water formations in an animal's wake. The bumps on a whale's flipper help form vortices that generate more lift, more smoothly. Engineers are using this insight to design an entirely new wind turbine blade—so that we can generate power from wind as efficiently as whales and dolphins fly through the water.

—Cynthia Graber

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