It has long been a mystery to solve for scientists as to how owls succeed in being such great hunters without letting their preys become even a tad aware of their descent.
Earlier this year, in June; researchers from the University of Cambridge and three other US institutes started an experiment to learn the mechanism behind owls’ “silent flight mechanism”.
They prepared material similar to the one found in an owl’s wing and discovered that it has got such great capability of decreasing noise that it can potentially be used in wind turbines or aircraft, whose noise levels have long been a public issue.
The research team further discovered that this owl’s wing-mimicked material if used in wind turbines not only will decrease noise pollution, but also make the blades operate at a greater speed, thereby generating more electrical power.
The structure on an owl’s wing is such that when air passes over it, it decreases noise by flattening the passage of air, thereby dispersing the sound everywhere, making it unable for their preys to hear the flapping sounds of it.
Although the scientists of this research are yet to apply the material fostered on operating wind turbines and then onto aircraft they believed it could be a breakthrough discovery.
Dr. Helen Czerski, a physicist at University College of London told BBC’s Today Programme: “If owls can fly more silently then airplanes can too. Anything having wings could be a lot more silent if this technology could be comprehended…Anything that’s got wings could be a lot quieter if you can understand this technology.”
It may be recalled that the much-awaited ‘Silent Aircraft Initiative’ aims at developing a soundless jet engine for aircraft by 2030, with its noise almost imperceptible outside the airport.
The conceptual design of the project has already identified the challenges and thus provided a direction for the work needed to address them. In addition. some of the technologies and approaches could be used in more incremental aircraft designs and one of them would be of Owl’s stealth technology that puzzled scientists for decades.
One approach was to alter the Continuous Descent Approaches (CDAs) which reduce noise and fuel burn by eliminating level segments, keeping aircraft higher and at lower thrust levels for longer than traditional step-down approaches.
The project, carried out by the University of Cambridge and MIT as part of a Knowledge Integration Community of aerospace partners, which include industry, airline and airport operators, policy makers and academics, is yet to explore the possible alternative technologies.
The findings of the research was presented at the June 22 American Institute of Aeronautics and Astronautics (AIAA) Aeroacoustics Conference in Dallas.
Jinkui Chu, who is the professor of Dalian University and a lead researcher of a new study, has indicated that by utilizing “stealth techniques” that owls are armed with.
Producing the proper thrust, just enough for a bird to rise high requires a good amount of force and disrupts a lot of air. Nonetheless, majority of the owl species accomplish to do it at below 2 kHz frequencies, which is nowhere near their prey’s audible range.
Being stunned to notice that an owl’s flying capability is a lot higher than their expectations, Chu further said that besides subduing aerodynamic noise when soaring high, owls subdue mechanical noise as well that are triggered by wing vibrations at the time of flying. “This is remarkable, considering the noise that creates for other birds,” he added.
This study has been published in the Institution of Civil Engineer’s journal “Bioinspired, Biomimetic and Nanobiomaterials”