Every year, humpback whales undertake migrations of over 20,000 kilometers to the polar regions, where the very agile and elegant animals spend the summer, and back to their breeding grounds. In addition to their long migrations, they are also known for their elegance and agility, which they owe in part to their distinctive pectoral fins. These are precisely what a Korean company has taken as a model for its product, which is used in a completely different area, namely in the air.
What do humpback whales and flying have to do with each other? At first glance, not much, since the animals live in the ocean and need air only to breathe. But if you look at the way the whales, which can weigh up to 30 tons, swim, you can see that they rightly bear their Latin name Megaptera. This is because the greatly enlarged pectoral fins allow the animals to maneuver much better than comparably sized whale species, and it appears as if the animals are flying underwater. The comparison is not completely false either, as similar factors play a role in terms of flow dynamics and the adaptations of animals, whether in the air or in the water. Companies that develop and produce aerial vehicles are also taking advantage of this.
The Korean company GIN Gliders is a manufacturer of paragliders and in the further development of their Boomerang-11 glider they were inspired by the pectoral fin edges of humpback whales, more precisely by the tubercles that sit on the edge and the edge shape. According to Korean expert Professor Jooha Kim of Korea’s Ulsan Institute of Science and Technology, “The tubercles on the pectoral fins of humpback whales improve performance and lifting force at high angles of attack. This gives the whales incredible agility despite their massive size.” The company’s owner, Gin Seok Song, also realized that this could become important for the further development of their paragliding chutes. That’s why he founded the development company GIN Labs with Professor Kim and set about implementing the concept.
Kim and the team at GIN Labs soon realized that tubercles were the solution. “Tubercle airfoils always stall gradually and can be operated at higher pitch angles which produces increased lift.,” he explains. “Drag penalty is significantly reduced and tip stalling can be attenuated and even completely eliminated. This combination of performance characteristics means that tubercle wings are hyperstable and very efficient.” To achieve this, the developers and engineers not only used computer simulations, but also wanted to test their ideas in the wind tunnel. “We decided that the wind tunnel would be a valuable tool, allowing hundreds of experiments and quick iterations on small modifications,” says Professor Kim. After a good model was developed, the team built real paragliders as prototypes and these showed that they performed much better especially in relation to wing stability and sink rate during the climb. “We decided to call the new technology Wave Leading Edge,” company owner Gin Seok Song proudly explains. “Because it is inspired by marine life and features a sinusoidal appearance.
The development of the new technology took a total of 1.5 years, and after certification, the company was able to demonstrate clear successes. At several Paragliding World Cup races, the new development proved its improved performance. “We’re really excited about the future of Wave Leading Edge,” says Gin Seok Song. Sometimes it just pays to look over the edge. And for humpback whales, it shows that their evolutionary recipe for success elevates them to the skies, but without having to leave their oceanic habitat.
Dr Michael Wenger, PolarJournal
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