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Author Topic: Is it possible to make an aircraft that flies like a bird?  (Read 4145 times)

Offline Arrual

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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?


 

Offline alancalverd

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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".
 

Offline jccc

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See a bird crash and die?
 

Offline chiralSPO

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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...)
« Last Edit: 31/01/2015 20:43:55 by chiralSPO »
 

Offline jccc

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With passengers?
 

Offline CliffordK

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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(]
 

Offline jccc

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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
 

Offline alancalverd

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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.
 

Offline Arrual

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Offline Don_1

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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

BUT........ then again......... https://www.youtube.com/watch?v=Pn5pPy9BX3w
 

Offline domkarr

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Re: Is it possible to make an aircraft that flies like a bird?
« Reply #10 on: 22/02/2015 00:09:04 »
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.
 

Offline dlorde

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Re: Is it possible to make an aircraft that flies like a bird?
« Reply #11 on: 22/02/2015 00:23:03 »
The Festo Smartbird is pretty good, but it would be difficult to scale up because the power to weight scaling is disadvantageous.
 

Offline PmbPhy

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Re: Is it possible to make an aircraft that flies like a bird?
« Reply #12 on: 06/03/2015 06:32:05 »
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.
 

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Re: Is it possible to make an aircraft that flies like a bird?
« Reply #12 on: 06/03/2015 06:32:05 »

 

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