Naked Science Forum
Non Life Sciences => Technology => Topic started by: Arrual on 31/01/2015 15:56:58
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Is it possible for an aircraft to take off and fly just like a bird and with all the same motions?
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Yes, but....
There are some neat little toy ornithopters that come close to bird and insect flight, but given the complexity of movement and the fairly slow progress of flying creatures, we have found it preferable and vastly more efficient to make rigid streamlined shapes powered by rotating machinery. The problem with nature is the absence of a living joint that can sustain continuous rotation: once you have overcome that, you can generate a lot of power and deliver it to a propellor or turbine.
The best glide ratio of any bird seems to be about 20:1 at 40 kt but after only 100 years of evolution we have aircraft with 60:1 glide ratio at 60kt, and even airliners capable of carrying several times their empty weight (way beyond the capability of any bird) manage 12:1, so "rigid is better".
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See a bird crash and die?
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See a bird crash and die?
Yeah, all the time! I used to work in a lab with huge, new windows. There was a short period when one bird per week would kill itself on those windows.
A few times it really scared me (imagine carefully setting up a reaction with some highly reactive reagents, and suddenly POP! another bird has brained itself 5 feet away from you...)
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With passengers?
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I wonder what it would feel like to be in an ornithopter.
Wouldn't the fuselage experience a forward/upward surge during the down flap, and a slowing/falling during the recovery phase.
It might be good for stirring up one's stomach [xx(]
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I wonder what it would feel like to be in an ornithopter.
Wouldn't the fuselage experience a forward/upward surge during the down flap, and a slowing/falling during the recovery phase.
It might be good for stirring up one's stomach [xx(]
Ask chiralSPO
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The Airbus 380 comes fairly close. Particularly during the takeoff run with a full load, the aircraft surges and wallows like a stork. Rigid isn't completely rigid, and the wingspan seems to be wider than the convection cells around a hot runway, so some parts are going up whilst others are going down. Weird at best, unpleasant at worst, but a cheap way to fly a long distance.
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With passengers?
yeah
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The stress caused by such wing motion, would restrict the size and useable lifespan of any such vehicle.
Then there is the sheer complexity of the wing, its joints and muscular requirements.
Man has tried, to the eternal amusement of millions and the woe of the doctors who try to put the nutcases back together after their dismal and predictable failure.
https://www.youtube.com/watch?v=8y3fIr4dVYE (https://www.youtube.com/watch?v=8y3fIr4dVYE)
BUT........ then again......... https://www.youtube.com/watch?v=Pn5pPy9BX3w (https://www.youtube.com/watch?v=Pn5pPy9BX3w)
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I thought that all aircraft where designed with the same basic principles as a bird uses for flight (not the thrust though) as the air friction against the wing causes upwards force? I think it would probably make a very useful spy plane for the yanks designating targets to have such a craft but I am with rigid being better for the passengers.
At any rate I am sure that it could be achieved by a series of gyro's, fine struts and robotics. It's just that it would need a new method of control, be very flimsy and therefore short lived as previously mentioned.
The joint's or struts would probably give out the first time there was a strong gust of wind.
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The Festo Smartbird (https://www.youtube.com/watch?v=nnR8fDW3Ilo) is pretty good, but it would be difficult to scale up because the power to weight scaling is disadvantageous.
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Is it possible for an aircraft to take off and fly just like a bird and with all the same motions?
Gliders work the same way an eagle glides through the air, i.e. by riding air currents. The wings don't flap for them to work when in the glide mode.