Posted on 01/18/2022 8:35:41 AM PST by Scarlett156
Trailing-edge noise is the dominant source of sound from aeronautical and turbine engines like those in airplanes, drones, and wind turbines. Suppressing this noise pollution is a major environmental goal for some urban areas.
In Physics of Fluids, researchers from Xi'an Jiaotong University used the characteristics of owl wings to inform airfoil design and significantly reduce the trailing-edge noise.
"Nocturnal owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration," said author Xiaomin Liu. "Moreover, when the owl catches prey, the shape of the wings is also constantly changing, so the study of the wing edge configuration during owl flight is of great significance."
Trailing-edge noise is generated when airflow passes along the back of an airfoil.
(Excerpt) Read more at phys.org ...
“Those giant muscular feet are the best landing gear. “
But aren’t they going at about zero velocity when those claws touch their landing point?
Do you know why an owl can turn its head almost all the way around? It’s because its eyeballs are so big that it can’t turn them independently of its head.
Soon quiet helicopters.
Wind turbine noise. Oops. But I thought wind power had no downside...
Last week while putting out my bird feeders and walking through the yard I saw a large circle of blue jay feathers (about two feet in diameter). I thought it must have been one of our ever present hawks that caught its dinner but it could have been one of our barred owls that live in our neighborhood. That bluejay did not have a good end.
It appears every time I read about a new breakthrough, it’s coming out of China.
Blue Jays are asshole birds.
Not to mention their baseball team, they ain’t even American.
Hey TG
Survival of the pffttt.
Your theory lacks evidence. But it has a large imagination.
Fig 3. Schematic of geometric models of the (a) owl-based airfoil, (b) oblique-arc trailing-edge serrations, and (c) conventional trailing-edge serrations.
“Your theory lacks evidence.”
Your theory?
Owls are bad omens. I had an owl fly into my house window (it left a dust impression on the window). A week later my dog died.
My torment always entertains people. The upside is that I’m me.
There’s always a downside to wind turbine power. Owls and many other birds are unnecessarily slaughtered. Personally I’m not in favor of turbines. Just passing on an article I read.
boundary layer shedding? or not fast enough
Wow, cool!
Thank you for posting!
Poor Brandon! :(
Maybe the turkeys and owls are acting in partnership. (Turkey hunting takes a lot of skill btw! You can see 20 turkeys and then really... slowly... get your gun out and by the time it’s cocked, there are no turkeys!)
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