Ornithopter(s)

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REVAN

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Although I'm a big fan of ornithopters and like to see progress being made in this field, this machine falls in the ridiculous category. Helicopters look elegant, by comparison.

I hope the work they have done on the many many iterations needed to get it flying goes somewhere better than my imagination envisions for this architecture.
 
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Aesquire

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I'll give the OP ornithoptor guys credit for not making bird looking wings and using basic rectangular ones.

Far too many have copied the appearance of bird's wings but not the functionality trying to fly. The Wright Flyer didn't have tip feathers unlike several failed previous designs. Seeing beyond the pretty to the function is a talent.
 

henryk

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ornithoptor guys credit for not making bird looking wings and using basic rectangular ones.
=this young engeneers from prof.Kiselov scuul are continued work
in "one way street"...

-but it exist experimental works with flapping (OSCILLATING) surfaces
(fan,wing) of dr Sorokodum =1900 N/ HP specific thrust !!!,
simplest construction, very complicated nonsteady aerodynamic=



=> 1:30 ...thruster measuraments.
 

Aesquire

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One new sport is pumping a hydrofoil board. By shifting your weight fore & aft while pumping, almost jumping, you skim along above the water until you tire out. You are gliding the underwater wing up & down to generate forward thrust, and coasting to glide along...

My Father taught me to pump drive a canoe. Standing near the CG, but not on it, you porpoise up & down and the asymmetry drives the canoe forward at speed. ( or backwards if you want )

it's really the water equivalent of a stick-slip phenomenon used by windup toys.

I tried pump climbing Rogallo wing hang gliders back when we all had to walk fast to keep our feet from burning because the Earth hadn't cooled off yet. I never accomplished anything better than momentary zoom climbs and a flight path that averaged worse than a straight glide, bleeding energy away, but it wasn't a wing designed to articulate to provide asymmetric thrust so it doesn't disprove ornithoptor flight, even if I ignore the Pterandons that were a safety issue back then.
 

AdrianS

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What's fascinating about that video is how still the body is as the wings flap.
Clearly the up and down strokes are timed to balance out up and down lift.
Note also that the two sets of wings are not exactly opposite phase.
 

REVAN

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I'll give the OP ornithoptor guys credit for not making bird looking wings and using basic rectangular ones.

Far too many have copied the appearance of bird's wings but not the functionality trying to fly. The Wright Flyer didn't have tip feathers unlike several failed previous designs. Seeing beyond the pretty to the function is a talent.
I removed credit for that. The wings are made like model airplane wings, instead of ornithopter wings. It has independent parts pivoting on a rigid spar for twist rather than flexing for twist. This basically eliminates the span-wise wing bending modes of the wing. That leaves a lot of potential ornithopter efficiency out of reach for this design. That may be why it needs 8 wings to fly instead of 2, or even 4 like the dragonfly.

That rigid spar is a big problem. Only very small ornithopters flap a mostly rigid wing. Larger wings need multiple bending modes. The flap is not rigid, but a wave. It is better both structurally and aerodynamically.

Another advantage of ornithopters resides in incorporating the flight control into the flapping motion. It appears that the flapping of this ornithopter only provides propulsion. A useful system would also provide control and wing folding in one system architecture.

I applauded the 'stick-to-it' attitude of these guys. It takes a monumental amount of work to get something like this flying. However, I can't help but thinking that there are some basic principles of flapping wings that, if they had known, would have taken them down a very different design path.
 

henryk

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basic principles of flapping wings that, if they had known, would have taken them down a very different design path.
flapping wing generate some vortices with huge energy...

-it exist fenomenon=vorticis can suck energy from calm air,
as warm pump do.

 

mcrae0104

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Has anyone posted this yet?

My Russian is not too good, so I have no idea what he said.

But I do recall my old friend Maude Frickert recounting the story of her brother Maynard, who had scotch taped 146 pigeons to his arms... he was airborne for a good twenty seconds, she said, until somebody threw a bag of popcorn in the stone quarry.
 

bmcj

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My Russian is not too good, so I have no idea what he said.

But I do recall my old friend Maude Frickert recounting the story of her brother Maynard, who had scotch taped 146 pigeons to his arms... he was airborne for a good twenty seconds, she said, until somebody threw a bag of popcorn in the stone quarry.
I can just imagine Jonathan Winters telling that story.
 
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