PRANDTL-D No. 3 Takes Flight

This 1-minute, 45-second video describes how NASA¹s Preliminary Research Aerodynamic Design to Lower Drag (PRANDTL-D) No. 3 aircraft successfully flew its first flight on Oct. 28, 2015. This flight test is the first of many that are aimed at improving flight efficiency.
Engineers estimate future aircraft could see more than a 30 percent increase in fuel economy. The new wing design eliminates the weight and drag of the modern aircraft tail and its flight control surfaces.
For more information: www.nasa.gov/ce...

[@ColtonCampbell]

Man that's a beautiful plane. Would love to work on an advanced concept like this someday(:

[@AstraGT]

WOW! It is an absolute pleasure to watch this project progress! I hope to work with the team soon! We've got the RIGHT STUFF, Al!

[@pinkdispatcher]

For anyone not aware of this, Ludwig Prandtl was one of the pioneers of the mathematical foundations of modern aerodynamics.

[@ericoschmitt]

Whats the glide ratio of it? And what might be it in a full scale sailplane with a prone pilot, similar to a Horten glider?

[@brianjacobs247]

The wingtips have elavons which generate thrust due to Prandtl effect. They also provide stability that would otherwise require vertical stabilizer. One advantage with such a wing is the extremely low drag and maximum lift. It seems intuitive that such an aircraft would be more efficient than a round tube with wings stuck on, which is how all commercial are. If one wishes to have a solar-powered autonomous aircraft that could stay aloft indefinitely, then this design seems ideal. Such aircraft could conceivably fly up to the stratosphere and remain airborne for months, providing communications capability over large rural areas without need for satellites or terrestrial cellular network towers.

[@spermorg]

I'm sure that the aboriginals have a patent on that.

[@SimpleKeep]

He has released his research paper including the relevant equations and wing twist distribution. On Wings of the Minimum Induced Drag Spanload Implications for Aircraft and Birds: ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003578.pdf

[@captarmour]

Wow amazing video, this is the future of aircraft design! works amazing in ground effect too!

[@Paiadakine]

Modern version of the Horton iv? Nice histart launch.

[@akkudakkupl]

Not really, they use the Prandtl method for getting bell shaped lift distribution ;-) But the effect is the same that the Hortens got.

[@JacobBogers]

yes, !

[@biggusdickus8335]

what's it gonna be used for?

[@SladkaPritomnost]

Beautiful!

[@captarmour]

Any powered versions? How would P Factor be managed on TO with no rudder? I want to build one! I also noticed it is very stable in ground effect.

[@jazldazl9193]

outer wing thrust or drag

[@kennethhawley1063]

You would need to make sure there is no P factor, using either a jet engine or counter/contra rotaing props. Suggesting the bell shaped load distribution is the secret of bird flight, is a gross simplification, bird flight is much more complicated than that.

[@JacobDavidCCunningham]

Damn that's sleek

[@chrismofer]

beautiful, you can really see the yaw coupling.

[@FPVREVIEWS]

does this use proverse yaw?

[@pinkdispatcher]

+FPVREVIEWS Ugh. I "proverse" is one of the ugliest new words that now seems to crop up everywhere. It is called "positive roll-yaw coupling". "proverse" is *not* the opposite of adverse. In which language is "ad" a prefix for negation? This is almost as bad as "repeller" for a (wind) turbine.

[@scurvybill]

+pinkdispatcher The aerospace industry has used "proverse" as the word to describe positive roll-yaw coupling for a while now. What's so bad about that? The latin makes sense. Regardless, even if you do find it bad, it's what is actually being used right now.

[@pinkdispatcher]

+scurvybill In what way does the latin make sense? The prefix "ad" means "to, towards", and "verse" is a derivative form of "to turn"; but the entire word has had a shift of meaning to be "adverse", "against". So how does replacing a prefix meaning "to" by a prefix meaning "for" make any sense? Such derivatives are almost always coined by people who don't know latin and replace what they perceive to be a prefix by another prefix they think means something else. The worst of the lot is probably "drag chute". Look up the etymology of parachute and you'll see the utter nonsense. I know language develops and In time all these may come to be the generally accepted terms, but as long as they are not, they make the hair on the back of my neck stand up and I'll continue to point out how silly they are.

[@valeriooddone]

Well, suggest maybe a shorter alternative to "positive roll-yaw coupling" at least

[@hugogirod1606]

pryc, eventhough it sounds like another word

[@tlcmailes3837]

this looks soooooo right :>>>

[@jackdraney5376]

Wow that things thin! It's so small it's practically dimensionless!

[@ManjitSingh-kr6mi]

This is awesome 🇺🇸👑💕

[@Varue]

now use a boundary layer suction device on it too 😂

[@joshtamargoderothschild2420]

also called 'Horten ho VI" ...

[@jayfmiller]

It sure loves ground effect.

[@planetmchanic6299]

Prettiest plane on the planet. What fun.

[@generalripper1964]

B-3, LRS-B maybe a new bomber? ;-)

[@petegarnett7731]

Northrop did it with the YB40. They preferred the B36.

[@generalripper1964]

@@petegarnett7731 It would have been interesting to see how things may have progressed with the YB-40 over the more conventional B-36.

[@WheatleyOS]

Who else is here from the NASA OSSI website? lol

[@limadeltazulu]

Flying wing. my colleagues modelers, they did 25 years ago :D

[@valeriooddone]

Read about the Prandtl Wing. It is not only a normal flying wing, but a bit more

[@sloth6765]

Valerio Oddone what more? I little wing twist on the edge? Honest interest. No real info in these KZbin comments.

[@joshtamargoderothschild2420]

Horten did it 70 years ago.. ;)

[@JohnBodylski]

@@sloth6765 Ok ill bite... Where as typical flying wings use twist, a washout, this one takes advantage of a derivation Ludwig Prandtl did in 1933 which looks not as a constrained wingspan, which is what gave an elliptical lift distribution, but rather a constrained mass. Instead of asking "what is the best lift distribution for a given wingspan" he asked, "what is the best lift distribution for a given mass of material?". The answer turned out to be a different shape, which to steal a term coined by the Horten brothers, is bell shaped. (No, Prandtl and the Hortens did not collaborate...) This shape cannot be made by strict linear twist, and takes on an even more complicated twist when taking taper ratio into account. One advantage of using this lift distribution is that the flow transitions from downwash to upwash around 70% span location. Contrary to some comments I have seen, the local angle of attack is always positive on a properly designed and flown wing like this. This means that increases in lift in these outer portions of the wing will have a forward component, which can be leveraged to maintain yaw stability in a turn. For a more detailed look you can find Albion Bowers paper "On wings of the minimum induced drag" from 2016.

[@marc_frank]

@@JohnBodylski how do i put the bell curve spanload on another wing?