I read the article in reader mode so I didn't see the video. After I went back to check out the video I was surprised that the submerged paddle were going in a circle instead of a straight line.
How can they say they too many birds cause the later positions to be unstable if this is their model? Don't they just run out of circumference and so they can't really model so many birds because the paddles start to overlap?
I suppose the math models the higher number of birds but they didn't 3d print that math and put it in a fish tank.
Read it dont know how new this is even though they coin a new term “flonon.”
Karmen vortex shedding is the way I’ve heard it described and birds being highly sensitive to changes in pressure essentially ride the vortex sheds from the birds in front. Once the paper is tracked down I’m eager to see if there is something truly new!
Fish do something even more incredible where they line the vortex sheds up where the add constructively to their velocity. Trout seemingly being so optimized that they can flow up stream even when dead!
I was at a Chihuahua meetup a few weeks back. when a large lone dog wanders into a pack of 30 odd little chihuahua's, they all start to swarm and flock like starlings. even though they dont "know" each other... its quite a thing to watch
Competitive flat-water kayakers do this too, it's referred to as "wake hanging", but the vortices from the kayaker in front's strokes definitely plays a part in spacing
I'm not convinced this is unknown. How is this any different from say Karman vortices? I also question how well a paddlewheel in water scales to and models a birdwing in air.
Cyclists try do draft when possible. When there is no wind, or the wind is from ahead, it's simply: ride behind the rider in front of you. But when the wind comes from the side, it's best to position yourself somewhat to the side of the rider ahead. In my experience (but I have to admit I my experience is quite limited) it's actually surprisingly difficult to find the best position in that case.
The importance of these swirling, vortices of air trailing off wingtips in a flock of birds is wonderfully revealed in Fred Bodsworth's book, "Last of the Curlews." After reading this book, you realize how physics and billions of years of evolution not only brings wings into the world, but also magnificence.
"Occasionally one of the curlew's wings would bite into the harder, spiraling air of a vortex left by the the wingtips of a migrating shorebird ahead of him, for even the passage of another bird left a trail in the air that the curlew's delicately sensitized wings could detect. Usually this alteration in the air pattern was the curlew 's first warning that he was overtaking a flock of birds ahead. When he found one of these vortexes, the curlew took advantage of it and followed it with one wing riding the updraft edge of the horizontal column of spiraling air. In this way he found a degree of lift readymade for him and his own wings could work a little easier.
But no other shorebird except the golden plover flew as fast as the curlew did, and each time he slowly overtook the bird producing the vortex ahead. First he would hear the faint twitter of a flock's flight notes, the vortex would grow stronger, then the birds would appear as blurred figures against the grey sky in front. The curlew would fly with them for a time, but his greater speed would gradually drive him ahead. Then once more he would be flying alone."
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[ 2.1 ms ] story [ 60.0 ms ] threadHow can they say they too many birds cause the later positions to be unstable if this is their model? Don't they just run out of circumference and so they can't really model so many birds because the paddles start to overlap?
I suppose the math models the higher number of birds but they didn't 3d print that math and put it in a fish tank.
Karmen vortex shedding is the way I’ve heard it described and birds being highly sensitive to changes in pressure essentially ride the vortex sheds from the birds in front. Once the paper is tracked down I’m eager to see if there is something truly new!
Fish do something even more incredible where they line the vortex sheds up where the add constructively to their velocity. Trout seemingly being so optimized that they can flow up stream even when dead!
https://fyfluiddynamics.com/2018/07/when-i-was-a-child-my-fa...
It wouldn't take PhD's or studies to figure it out - it's a bit like noticing that it's more effort to run than walk.
Cyclists try do draft when possible. When there is no wind, or the wind is from ahead, it's simply: ride behind the rider in front of you. But when the wind comes from the side, it's best to position yourself somewhat to the side of the rider ahead. In my experience (but I have to admit I my experience is quite limited) it's actually surprisingly difficult to find the best position in that case.
"Occasionally one of the curlew's wings would bite into the harder, spiraling air of a vortex left by the the wingtips of a migrating shorebird ahead of him, for even the passage of another bird left a trail in the air that the curlew's delicately sensitized wings could detect. Usually this alteration in the air pattern was the curlew 's first warning that he was overtaking a flock of birds ahead. When he found one of these vortexes, the curlew took advantage of it and followed it with one wing riding the updraft edge of the horizontal column of spiraling air. In this way he found a degree of lift readymade for him and his own wings could work a little easier.
But no other shorebird except the golden plover flew as fast as the curlew did, and each time he slowly overtook the bird producing the vortex ahead. First he would hear the faint twitter of a flock's flight notes, the vortex would grow stronger, then the birds would appear as blurred figures against the grey sky in front. The curlew would fly with them for a time, but his greater speed would gradually drive him ahead. Then once more he would be flying alone."