字幕列表 影片播放 列印英文字幕 Try as we might - we cannot master the flight of the hummingbird. Hey everyone this is Carin for DNews and today we are talking about human attempts to replicate mother nature. Biomimicry is the term used to describe technologies that we develop to try to be as awesome as the structures and functions we observe in the animal kingdom. Things like slug slime and spider silk have been mimicked in many scientific studies; however, today’s example comes courtesy of the bird world. Hummingbirds move with awe-inspiring speed. Their tiny wings can flap at such high frequencies that they are audible to human ears - hence the name hummingbird. The fastest flappers are flapping up to 200 times per second. Hummingbirds are also masters of the hover - maintaining their aerial positions with what seems to be very little effort. Scientists have long been interested in mimicking the flight techniques of hummingbirds, and our most efficient microhelicopters actually do a pretty respectable job. The Prox Dynamics Black Hornet autonomous microhelicopter is the most sophisticated available - these tiny drones are about the same size as hummingbirds and they are currently used in Afghanistan by the English army. But how efficient are these autonomous helicopter drones? A recent study led by David Lentink at Stanford university looked into that question. The researchers analyzed the aerodynamic properties of hummingbird feathers from twelve different species and compared them to the blades of the black hornets. Specifically mounted cameras allowed the researchers to visualize airflow around the bird wings and helicopter blades that were spun on an apparatus designed for this exact purpose. In addition, sensitive load cells were used to measure both lift force and drag on the feathers at various angles and speeds. In other words - how hard does a bird have to work in order to achieve lift or to maintain its position in the air? Do the helicopter blades have to work harder? Actually, no. The news isn’t terrible, but we’ve clearly got a ways to go. Lentink and his team found that microhelicopter blades were able to hover with an efficiency that rivals that of an average hummingbird - which is pretty darn impressive. However, hummingbirds with top flight wings such as those of the Anna’s hummingbird, common on the west coast of North America, are able to increase efficiency over the helicopters by a staggering 27%. The best engineers in the world remain outperformed by the power of evolution! Overall, this work most definitely represents a significant achievement in the study of aerodynamics….but there’s more work to be done in order to create technologies that rival the movement patterns of hummingbirds. I mean, think about it - this was just one aspect of hummingbird flight - hovering. What about diving, navigating through complex environments or flying through wind gusts?? Not to mention that hummingbirds actually flap their wings - this study looked at the movement of spinning. If hummingbirds could actually move by spinning their wings like a helicopter they would only utilize half as much energy as they currently do. When it comes to biomimicry, there are many more secrets to be discovered from hummingbirds and countless other organisms about amazing ways they carry out their day to day functions. Which animal do you think we should try to mimic and why? Leave your answers in the comments below, and subscribe here for more DNews every day of the week. See ya next time!
B2 中高級 美國腔 蜂鳥能教我們如何飛行? (What Hummingbirds Can Teach Us About Flying) 639 28 葉怡芬 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字