Do Sharks Hold the Secret to Faster Planes?

Harvard University scientists creating the next generation of air foils are looking under the sea in a quest to mirror Mother Nature’s singular ability to create the perfect wing.

For most of human history, man has looked to the sky to draw inspiration for our own dreams of soaring above the clouds. Those dreams long ago turned from fantasy to reality and mankind has since risen past the clouds to reach the stars, but in many ways, aeronautical engineers are still chasing the simplicity and flawless efficiency of the world’s winged beasts.

Countless man hours and fortunes in investment have been spent to achieve the goal of more “bird-like” air travel. Now, it seems we are turning our attention from the skies to the seas to help us glean some of Mother Nature’s best kept secrets of flight.

According to a just published research paper in the Journal of the Royal Society Interface, while possibly solving an age-old mystery about shark scales, biologists at Harvard University may have helped engineers at the University of South Carolina to create more efficient air foils. The report, “Shark skin-inspired designs that improve aerodynamic performance,” published last month may just fundamentally change the way we think about aircraft wings.

“The skin of sharks is covered by thousands and thousands of small scales, or denticles, which vary in shape and size around the body,” Harvard Professor of Ichthyology and co-author of the paper explained on the Harvard John A Paulson School of Engineering and Applied Sciences (SEAS) website. “We know a lot about the structure of these denticles — which are very similar to human teeth — but the function has been debated.”

It turns out that engineers rather than biologists may have been best equipped to solve this debate all along.

“We asked, what if instead of mainly reducing drag, these particular shapes were actually better suited for increasing lift,” University of South Carolina Mechanical Engineering Professor Mehdi Saadat and co-author added.

After putting this interesting theory to the test, both the engineers and biologists involved were satisfied that a riddle had been solved. In the end, proving that a shark’s unique scales are excellent at both reducing drag and increasing lift may have led to ground-breaking real world applications as well.

“We discovered a set of denticle-inspired surface structures that achieve simultaneous drag reduction and lift generation on an aerofoil, resulting in lift-to-drag ratio improvements comparable to the best-reported for traditional low-profile vortex generators and even outperforming these existing designs at low angles of attack with improvements of up to 323 percent,” the study concludes. “Our findings not only open new avenues for improved aerodynamic design, but also provide new perspective on the role of the complex and potentially multifunctional morphology of shark denticles for increased swimming efficiency.”

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