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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."
Its the scale effect. The scale at which the physical laws act is the same. Its not possible to make a human size water strider.
***Warning: Hearsay below***
Apparently once upon a time all articles submitted by Roland linked to his blog which linked to the real article (as a way to generate ad revenue, I think). And he continues to take flak for it to this day.
Like I said, this is second-hand from earlier discussions. I was not here when it was happening.
Finally! A year of moderation! Ready for 2019?
Enhancing Aircraft Conceptual Design using Multidisciplinary Optimization, by Dan Raymer.
[PDF] http://www.aircraftdesign.com/RaymerThesisFinalRevLowRes.pdf
Genetic algorithms are a pretty useful stuff, and already in use within aircraft design.
English is not my first language. Corrections and suggestions are welcome.
Not really... most are set at about a 15 degree angle; the F-16 is reclined to 30 degrees. That was first done to be able to fit the seat in the aircraft, and the small G-load benefit was discovered later. I think the F-22 and F-35 may also be set like that, but I'm not sure.
The meek may inherit the earth, but the strong shall take the stars.
All very true, but you missed the fact that when they started out, Hawaii and Alaska were closer. Today's Hawaiian Islands are the end of a long chain of seamounts that stretch out nearly to the Aleutians, with the seamounts getting older as you go northwest. We don't know when those plovers started this migration, but it was some millions of years in the past, when the end of the Hawaiian chain was one of those older seamounts that was then an island. It could have even been back when the islands were barely offshore from the then supercontinent of Laurasia (though it should be mentioned that we don't know this).
So their ancestors that started this migration had an easier job of it. As the islands slowly drifted out to sea, each generation would be selected for the survivors that were able to make a slightly longer flight.
Environmental change, in this case the effect of a moving geological "hot spot", must be taken into account to fully explain a lot of evolutionary events. That's one way you can get results that seem impossible in today's world, especially things like the colonization of remote islands like Hawaii by species that can't cross the open ocean.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
The idea of using wingtip devices to control vorticies has been around for over 100 years. Frederick Lanchester (a conteporary of Prandtl) secured a patent in 1897 for the use of "bent up wing tips" to control tip vorticies. He was working on those theories at the same time the Wright brothers were trying to learn how to fly. It took 20 years for aerodynamicists to prove his theories correct.
As you get bigger, the cross sectional area of your muscles and bones increases at the rate of L^2 [where L is the length], but your mass increases at a rate of L^3.
As your size increases, your mass quickly outstrips the ability of your muscles and bones to sustain it.
Interestingly, as your size decreases, it works the other way. Mass decreases at a cubic rate and strength [muscles/bones] decreases at a square rate. You become relatively much stronger.
Gerbils can survive falls from any height, elephants break at 5-6 foot drops.
This thread relates to Golden Plovers. http://pbc.codehog.co.uk/bhs/pics/200611/golden_plover_flock_19nov06_800l_20a.jpg">They do NOT fly in a V formation - they fly in a very random flock.. Very few small birds fly in a V formation. That tends to be larger birds like geese.