Dutchman flies by flapping his arms

[rksl-rock 1300]

I've just come across this...

Weekend Project: Build an Ornithopter

e3wWfKEdvpY

Try scaling it up...

[Nike619 1]

Clearly nobody remembers the shoe company video where they ran on water. It had people convinced as well. :rolleyes:

[rksl-rock 1300]

Clearly nobody remembers the shoe company video where they ran on water. It had people convinced as well. :rolleyes:

That was mentioned several pages ago. No one i discussed that with believed it either.

[PELHAM 10]

I've just come across this...

Weekend Project: Build an Ornithopter

Try scaling it up...

If you are going to be flying that aircraft regularly can I recommend these essential products for you and your passengers:

http://www.amazon.co.uk/Cleanis-Vom-Vomit-Bags-x20/dp/B003LY7CQW

[rksl-rock 1300]

If you are going to be flying that aircraft regularly can I recommend these essential products for you and your passengers:

http://ecx.images-amazon.com/images/I/41v7jtEXeYL._SS500_.jpg

http://www.amazon.co.uk/Cleanis-Vom-Vomit-Bags-x20/dp/B003LY7CQW

LMAO, no thanks I'll stick to flying this.

The wings already flap enough on the grass strip to qualify as an ornithopter. :p

Edited March 24, 2012 by RKSL-Rock

[hellfire257 3]

My god...what sort of contraption is that!? :O

It looks like something out of Catch the Pigeon.

[rksl-rock 1300]

My god...what sort of contraption is that!? :O

It looks like something out of Catch the Pigeon.

Thats is my friend's Long EZ (that he's letting me use occasionally). Im just starting to fly again - having to re-qualify after a few years on the ground due to finances and an overly large arse. Now I have more of one and less of the other flying for fun is becoming viable again.

[liquidpinky 11]

PELHAM pretty much nailed the fake at the start as they never had a proper upstroke of the wings, which I pointed out to my workmates as soon as I seen this the other day.

[PELHAM 10]

My god...what sort of contraption is that!? :O

It looks like something out of Catch the Pigeon.

It's a Burt Rutan contraption, I'm a big fan. Facinating aircraft, a true flight vehicle as it looks so awkward on the ground. The rear engine moves the centre of gravity so far aft that without someone sitting in the pilots seat it can topple over backwards, so they park it with the nose wheel up. In the air however, the centre of lift is perfect. At fly-ins the owners get fed up with people asking if the nose gear is broken. You can try original humour with them but it doesn't always work lol.

---------- Post added at 08:55 PM ---------- Previous post was at 08:53 PM ----------

PELHAM pretty much nailed the fake at the start as they never had a proper upstroke of the wings, which I pointed out to my workmates as soon as I seen this the other day.

Tonci said it was fake 1st.

[MrBump 10]

PELHAM pretty much nailed the fake at the start as they never had a proper upstroke of the wings, which I pointed out to my workmates as soon as I seen this the other day.

He did, damn I've been away and I missed it.

I am fully aware of ornithopters because I have this video saved on my hard drive - this is a real attempt that fascinated me at the time:

Honestly I don't think you knew what an orithopter was, and you certainly don't really understand how they work. The fact you originally posted a animation of a parrot's wing claiming that it's the "1000's of changes in each cycle of movement" that lead to flight, tells me that you've just been introduced to them, otherwise why did you post that, it's totally irrelevant.

That is exactly what I was talking about, you have to move the aerofoil in a precise way. Also Dead3yes example is perfectly correct because if an aerofoil is kept at the same angle while moving up and down it will produce no net lift or thrust. That is clearly what happens in the fake vid, the angle of attack doesn't change. With a wing of that chord you would be able to see it clearly. A better natural example of an ornithopter wing is a high speed insect wing. The wing twists to reduce air resistance on the upstoke as the ornithopter wing does, the insect just does it far more efficiently. My point still stands, any flapping wing has to twist or fold on the up stroke or you get 0 lift.

I said it on page 2.

The flight characteristics of an insect, with it's inflexible wing that requires rotational supination and pronation, is very different from a bird's flexible flapping wing, and not much like a ornithopter's wing that moves up and down. The insect wing does not 'twist' like a bird's because it is not flexible, it flips it's wing using rotation, the insect's wing foil does deform slightly based on the complex veins on the wing, but this is more for efficiency, as like a bird folds it's wing only for efficiency.

The insect's wing also doesn't reduce air resistance on the upstroke, it uses wind resistance on the upstroke as much as it uses it on the down stroke, this is done by producing a leading edge vortex. Hummingbirds (which also rotate their wings) and small bats, also use a leading edge vortex, to a degree, but their upstoke is nowhere near as efficient. Larger ornithopters (larger than Hummingbird size) do not use leading edge vortexes because they can't beat their wings fast enough to produce the eddies.

As for "A better natural example of an ornithopter wing is a high speed insect wing." I had to laugh. See there has never been a device that successfully replicated the rotational movement of inflexible insect wings, well not yet as far as I know, the insectothopter of the CIA was only partially successful, oh and for your knowledge, an ornithopter replicates only flexible wings like bird wings, that is why it's called ornitho(bird) pteron(wing).

Also in regards to "the angle of attack doesn't change", how do you figure that? You do understand that the angle of attack refers the the angle in relation to wind direction and/or in relation to chord line and flight direction, not some sort of horizontal absolute. How did you calculate these variables?

My point still stands, any flapping wing has to twist or fold on the up stroke or you get 0 lift.

Nope, as stated, in order for your 0 lift theory to hold, the wing would need to be inflexible, like say, an insect's wing, however this wing (like all ornithopter's wings) was flexible therefore your theory doesn't work. Let me explain simply to you, the two different ways a ornithopter can get it's twist...

The first way, the one that's most relevant here, the wing has a rigid leading edge that is fixed to the airframe with a flexible foil. This means that as the wing flaps, the inner part of the wing moves less than the outer part causing the flexible foil to deform and you got it! Twist! It's that simple. The difference in angle of attack on the upstroke and down stroke depends on airframe balance, wind direction and the wing's design. The second way is the DeLaurier way, one that has a semi-rigid wing that uses passive aeroelastic deformation.

Welcome to the world of ornithopters.

I called fake on this video for other reasons, and I'll call fake on your zero lift theory and your knowledge of ornithopters. :)

Edited March 26, 2012 by MrBump

[PELHAM 10]

Odd that you contradict a point and then agree with the same issue (much embellished) several times over? Those aren't my theories it's a cornerstone of aerodynamics and can be summed up in 1 sentence (I reapeat it here for the 3rd time):

"if an aerofoil is kept at the same angle while moving up and down it will produce no net lift or thrust" (to clarify thats for 0 air velocity relative to the leading edge)

If there is air velocity the aerofoil will produce lift but no thrust. That applies to felxible and rigid wings, insects, ornithopters, birds, anything that flaps (2nd statement also applies to anything that doesn't flap.)

My whole point about the video is the angle of attack does not change. So once in the air how does he maintain his thrust and where does the massive increase in lift come from? The velocity present from the pilot sprinting across the ground doesn't explain it. It's basic science, observation and common sense.

Maximum Power to you for going to all that effort as what you have posted about aerodynamics is perfectly correct and I enjoyed reading it.

Edited March 26, 2012 by PELHAM

[MrBump 10]

"if an aerofoil is kept at the same angle while moving up and down it will produce no net lift or thrust" (to clarify thats for 0 air velocity relative to the leading edge)

Yes and the keyword here is IF, ie if the conditions are correct to create zero lift. Like the old saying goes: if my aunty had nuts, she'd be my uncle. :p :D

Edited March 26, 2012 by MrBump

[rangerpl 13]

Yes and the keyword here is IF, ie if the conditions are correct to create zero lift. Like the old saying goes: if my aunty had nuts, she'd be my uncle. :p :D

Your "point" is meaningless and absurd. You can't produce lift by flapping your arms without changing the angle of attack. Period. The laws of physics and aerodynamics can't be argued with.

[MrBump 10]

Your "point" is meaningless and absurd.

My point that a ornithopter changes it's wings angle of attack by twisting the aerofoil between up stroke and down stroke is meaningless and absurd? No, I believe that's well proven.

You can't produce lift by flapping your arms without changing the angle of attack. Period. The laws of physics and aerodynamics can't be argued with.

Yep, so what?

[walker 0]

Hi all

So in the end it was the Greatest Fake so far ever done. Until the next great fake.

Cudos to the makers for the quality of the fake and the supporting details that made it so good. :)

Kind Regards walker

[Dead3yez 0]

Cudos to the makers for the quality of the fake and the supporting details that made it so good. :)

:icon_lol:

Come on... The authenticity was EXTREMELY questionable right from the bat.

[mrcash2009 0]

So in the end it was the Greatest Fake so far ever done. Until the next great fake.

That will be the alien invasion in real life, coming to a peripheral vision near you.

[rksl-rock 1300]

So in the end it was the Greatest Fake so far ever done. Until the next great fake.

And I bet you thought Battle: Los Angeles was a good film with fantastic Special Effects too. ;)

I really wish this was possible, I'd love to try it but it was just so obvious if you know anything about practical engineering.

[Tonci87 163]

That will be the alien invasion in real life, coming to a peripheral vision near you.

Nothing new, search for "War of the Worlds" 1938

[mach2infinity 12]

And I bet you thought Battle: Los Angeles was a good film with fantastic Special Effects too. ;)

It could be worse, could be Skyline ;)

Please let me have a list of projects you have worked on, I would like to avoid travelling on those aircraft. LMFAO

......*sound of brakes being applied* *SMASH*...looks like your train operations didn't take-off either ;)

Your "point" is meaningless and absurd. You can't produce lift by flapping your arms without changing the angle of attack. Period. The laws of physics and aerodynamics can't be argued with.

No they can but just not very convincingly.

Edited March 29, 2012 by Mach2Infinity

[MrBump 10]

I thought the Nano Hummingbird was pretty cool, plus it's been found that at small-scale, flapping wings are more efficient than fixed wing aerofoils because of the low Reynolds number... manned vehicles are a great way to get your neck broken, but MAV's could be something for the future.

[walker 0]

Hi all

MrBump I draw your attention to this talk at TED by DARPA Director Regina Dugan.

V_LurJfOSiA

It explains why we should never fear failure or dismiss our dreams, including the dream this fake fed on.

Kind Regards walker

Edited April 2, 2012 by walker

[jerryhopper 285]

Hi all

So in the end it was the Greatest Fake so far ever done. Until the next great fake.

Cudos to the makers for the quality of the fake and the supporting details that made it so good. :)

Kind Regards walker

yup... it aint much, if it aint dutch!

[rksl-rock 1300]

yup... it aint much, if it aint dutch!

OK well following on from Fake Ornithopters to something still, Dutch and still equally mad but just as amazing:

I dont know if this deserves its own thread but I just saw this and thought it is just as "cool" as a set of wings, more practical too.

BBC News: http://www.bbc.co.uk/news/technology-17592648

Company Website: http://pal-v.com/

A Dutch company is launching a vehicle which can be driven on land, or flown in the air.

SgHSaNtAMjs

The Personal Air and Land Vehicle (PAL-V) can be configured as a gyrocopter, requiring a 165m (540 ft) runway to take-off, or as a three wheeled car.

PAL-V chief executive Robert Dingemanse said that private individuals had expressed an interest in the machine, but he was also hoping that military and emergency services could find a use for it.

Several test flights have been successfully conducted and the company is now looking for investors to take the PAL-V through the final development stage.

I so want one... I wonder how much they are going to cost and will any country allow thier use by the public?

Edited April 2, 2012 by RKSL-Rock

[PELHAM 10]

The Personal Air and Land Vehicle (PAL-V) can be configured as a gyrocopter, requiring a 165m (540 ft) runway to take-off, or as a three wheeled car.

I so want one... I wonder how much they are going to cost and will any country allow thier use by the public?

I have always wanted an Autogyro. They fly over my garden regularly in the summer and I have investigated a PPL(G) and spent much time looking at plans for self builds.

http://www.chrisjonesgyroplanes.co.uk/

One thing our Dutch friends have not thought about with that PAL-V are European safety standards regarding road vehicles. They do not allow sharp edges that can injure pedestrians during a collision. They may get away with it as the front is smooth and rounded but around the rear wheels, tail surfaces and top there could be some issues. Not sure if it would pass from that respect but otherwise I would buy one depending on weight capacity. The early Gyros had a low weight limit so they wouldn't accept me as with an instructor weights were exceeded. I'm a 6'1" mountain gorilla lol. Need more power and bigger rotors!

eg this - turbine power, all it needs is rocket pods:

Edited April 3, 2012 by PELHAM