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Birds Give a Lesson to Plane Designers
Roland Piquepaille points out a news release from the University of Michigan where researchers are looking to birds and bats for insights into aerospace engineering. Wei Shyy and his colleagues are learning from solutions developed by nature and applying them to the technology of flight. A presentation on this topic was also given at the 2005 TED conference. From the news release:
"The roll rate of the aerobatic A-4 Skyhawk plane is about 720 degrees per second. The roll rate of a barn swallow exceeds 5,000 degrees per second. Select military aircraft can withstand gravitational forces of 8-10 G. Many birds routinely experience positive G-forces greater than 10 G and up to 14 G. Flapping flight is inherently unsteady, but that's why it works so well. Birds, bats and insects fly in a messy environment full of gusts traveling at speeds similar to their own. Yet they can react almost instantaneously and adapt with their flexible wings."
Current aircraft performance is limited by what the occupants can survive. Try to roll a human at 5,000 degrees per second and things would get messy.
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I hate commenting on another annoying stupid Roland article.
.. what's up with that?
Birds and insects have very low mass. As mass increases components have deal with more stress etc.
Post another annoying stupid Roland article when birds flying at high speeds weigh as much as an aircraft (or even a human) and then we'll see how they handle things.
Btw, I could have sworn i saw the "ohnoitsroland" tag and then it disappeared
Perhaps they can roll that fast, and take that many G's, because that's what they have done for thousands (if not millions?) of years. Their bodies have adapted to it, as they do it almost 24/7.
And haven't we already used bernoulli's principle watching birds, and applied that to planes, getting us in the air in the first place. Has it really taken us this long to realize that we can learn how to fly better from watching the things that fly naturally every day?
In addition, a bird's head is inline with its body, while pilots sit up and require g-suits to force blood back up into their heads. I wonder what forces the pilots could withstand if they piloted in a prone position, though I can't imagine that being very comfortable.
It must have been something you assimilated. . . .
Sometimes they come back.
Roland is off in bogosity land, as usual. The wingspan of a barn swallow is about 0.3m. The wingspan of an A-4 Skyhawk is 8.1m, which is 27x larger. So, scaled for size, an A-4 Skyhawk actually has about 4x the roll rate of a sparrow.
Historically, aircraft that looked or worked like birds have been spectacularly unsuccessful. Little ornithopter UAVs do work, but the ornithopter concept does not scale up well.
Sub designers, aircraft...cars...chairs...these guys/gals are supposed to have studied things like fish, birds, trees and insects for reasons why, and why not, long before they were hired to actually build things.
True, but it might be noted that we made very little progress in flying until some people gave up on trying to mimic birds, and tried other approaches. The first actual "flight" by humans was in the early 1800s, with hotter-than-air balloons. Then around 1900, a few experimenters started to get the hang of wings, and figured out that what worked was to separate the lift generation from the propulsion. Nature never came up with this scheme, but it's technically easier (if you know how to make a rotary motor or a jet engine) than nature's scheme of using wings for both functions.
Similarly, submarines look superficially like fish, but don't really work the same way. Fish use their fins for both steering and propulsion, while submarines use fins only for steering, with a propeller for propulsion. The similar shapes are only for streamlining, which does work the same for everything that needs it.
Usually, nature's solutions to problems are good models. But in cases like fish and birds, it has turned out to work better to give up on them and work from first principles. We're only now starting to produce machines that fly and swim like birds and fish, and they are little more than toys. Our non-natural solutions have turned out to work better for our purposes than what nature found.
We might also note that nature did discover a rotary motor, in the form of bacterial flagellae. We even have them in some of our cells. (Trivia question: Which cells are those?) But nature never figured out how to adapt them to larger, multi-cellular organisms. Maybe on some other planet, but not on this one. Nature also discovered jet propulsion, and uses it under water but not in the air. We know how to do both of these things on a larger scale, and we have used them to solve problems in ways that the evolutionary process hasn't found.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.