The Aerodynamics of Winglets

This video explains the aerodynamics of winglets and how they arrived to commercial aviation.
Have you ever wondered why the tips of the wings of an aircraft are curved up? It turns out that those wingtip devices are called winglets and are used to reduced aircraft's fuel consumption. When the wing of aircraft produces lift, by creating a pressure difference between the upper and lower surface, the high-pressure air at the bottom tends to sneak onto the top of the wing. This produces turbulent wakes called wingtip vortices and that decrease the performance of an aircraft through what is called induced drag. There are many ways to reduce induced drag. One of them is by designing longer wings, since these reduce the size of wingtip vortices. Another solution was found by Richard Whitcomb, a NASA engineer, during the 1080s: the winglets. Wingtip devices or winglets simply reduce induce drag by decreasing the size of those wingtip vortices. Although they are not always advantageous, and if designed improperly, can even decrease an aircraft's performance.
Chapters:
0:00 Introduction
0:45 Wingtip vortices
1:31 Induced drag
2:30 Background
3:01 Winglets
3:35 Disadvantages
5:09 Conclusion
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Credits:
Script and Production: Lucas Ferrando
Videos by StoryBlocks.com
Music by BendSound.com
Sonex Waiex-B video: Stirling Brandt
waiex_md?igshid...
Image of Winglet of A350XWB:
secure.flickr.com/photos/meda...
Image of HA 137:
commons.wikimedia.org/wiki/Fi...
Video of wingtip vortices:
upload.wikimedia.org/wikipedi...
Image of A320:
www.clipartmax.com/middle/m2i...
Image of Whitcomb in the Wind Tunnel:
airandspace.si.edu/sites/defa...
Image of MD11 in the Wind Tunnel:
www.flickr.com/photos/nasacom...

[@afsaralim7]

It's criminal that you don't have many subscribers. Great Explanation sir.

[@lucasferrando-english4512]

Thank you for the nice words, @afsaralim7

[@NelksLife]

Excellent job presenting winglets. Thank you!

[@lucasferrando-english4512]

NelksTV, I’m glad you enjoyed it. Thanks for the support.

[@hectormunoz659]

Lucas, great video, keep sharing this kind of information, the most modern winglets resemble more the natural shapes like the eagles wings!

[@lucasferrando-english4512]

Hector, thank you very much for the nice words. I'll start uploading more videos soon.

[@smesui1799]

ENGINEERING education matters. Time for aviation enthusiasts to hit the books !

[@lucasferrando-english4512]

It’s never too late for that.

[@smesui1799]

@@lucasferrando-english4512 Very true. Thank you !

[@saicharan7981]

Excellent video! Thoroughly enjoyed it.

[@lucasferrando-english4512]

Thank you very much! :)

[@onepairofhands]

nice presentation

[@lucasferrando-english4512]

Thank you for the support, Peter

[@user-gd4be2wk5c]

Very Very much thank!!

[@lucasferrando-english4512]

Thank you for the nice words

[@AR_434]

A winglet doesn't really reduce the size of the wing tip vortex. It actually uses it to produce thrust and thereby reduces the overall induced drag. Al Bowers from NASA talks about that in one of his videos. Nevertheless, nicely done video!

[@lucasferrando-english4512]

Winglets can indeed produce thrust but their main purpose is to increase the effective wingspan and aspect ratio of the wing, thus reducing induce drag.

[@lovelycarHossein]

Perfect

[@lucasferrando-english4512]

Thank you!

[@lucasferrando-english4512]

Thanks a lot for watching! I hope you enjoyed the video. Had you ever wondered what winglets were? What do you think of the most modern winglet designs?

[@ShonMardani]

Parasite drag is produced by VERTICAL surfaces and Induced drag is created by HORIZONTAL surfaces, for example when the Flaps are at 0 degrees they produce Max Induced drag and Min Parasite drag, at 90 degrees Min Induced and Max Parasite drag and at 45 degrees in the middle of both, for a flap with no thickness. The fact that Lift and drag are both proportional to airspeed squared, means airspeed affects a 2 Dimensional surface, geometrically a Square plane. Wing Vortices are not the cause of Induced Drag but it is just a Visible Effect of it. I have developed a hypothesis to explain physical, atomic and subatomic (gravitational movements, Center of Gravity and Mass), however I need to validate my V & H surfaces theory first. It seems that Winglets reduce Lift and increase Drag, I also believe in turbance Winglets impose additional stress to wings and all other moving parts inside the wings like rods, joints and moving surfaces. Wingtips also decrease the stability and controllability in turbulent air. Please let me know what you think, thanks.

[@tayeelshaikh9228]

Good job man

[@lucasferrando-english4512]

Thank you for the nice words, Tayeb

[@ShonMardani]

Parasite drag is produced by VERTICAL surfaces and Induced drag is created by HORIZONTAL surfaces, for example when the Flaps are at 0 degrees they produce Max Induced drag and Min Parasite drag, at 90 degrees Min Induced and Max Parasite drag and at 45 degrees in the middle of both, for a flap with no thickness. The fact that Lift and drag are both proportional to airspeed squared, means airspeed affects a 2 Dimensional surface, geometrically a Square plane. Wing Vortices are not the cause of Induced Drag but it is just a Visible Effect of it. I have developed a hypothesis to explain physical, atomic and subatomic (gravitational movements, Center of Gravity and Mass), however I need to validate my V & H surfaces theory first. It seems that Winglets reduce Lift and increase Drag, I also believe in turbance Winglets impose additional stress to wings and all other moving parts inside the wings like rods, joints and moving surfaces. Wingtips also decrease the stability and controllability in turbulent air. Please let me know what you think, thanks.

[@lucasferrando-english4512]

I think this is completely inaccurate.

[@ShonMardani]

I watched your video and realized that you too know the winglets are just a marketing scam. I thank you for your video and your reply. As a professional please explain scientifically and logically your reason(s) to invalidate my findings.@@lucasferrando-english4512

[@SoloRenegade]

there is almost no real aerodynamics in this video. you clearly do not actually understand winglets nor how they work. But that is common. Most people have no clue how they work. A person needs more than just a basic comprehension of basic aerodynamics to truly understand them. Your drag curves are weird for example. not sure why you added so much parasite drag, as the addition of winglets would be almost negligible. You talked a lot about induced drag, without every really explaining what it is, nor how winglets relate to it.

[@lucasferrando-english4512]

@SoloRenegade thanks for your comment. When making this video, I tried to condense as much information as possible in a 7 min format while keeping it in a way that is easily understandable by people without an engineering background. With that said, I’m pretty sure I know how winglets work as I have worked in the design of winglets in the past as well as consulted for the FAA on the effects of wake turbulence. Regarding the drag curves, they are obviously not to scale and are there solely for the purpose of explaining the change of drag with respect the lift coefficient. Lastly, induced drag was defined at 1:55 as the square of the lift coefficient divided by pi, the Oswald efficiency factor, and the aspect ratio. If you look at some other comments, I explained how a winglet increases the effective wingspan (and aspect ratio) of a wing.

[@SoloRenegade]

@@lucasferrando-english4512 "induced drag was defined at 6:00 as the square of the lift coefficient divided by pi, the Oswald efficiency factor, and the aspect ratio." Sure, that's an equation for Induced Drag, which matches the equation out of "Airplane Performance Stability and Control" by Perkins & Hage (other than the additional Oswald factor), but it is not the definition of induced drag, nor does it explain what Induced Drag is nor any explanation of what reduces or increases it. "If you look at some other comments, I explained how a winglet increases the effective wingspan (and aspect ratio) of a wing." exactly, it's not in the video. nobody is going to read all of the comments. "I tried to condense as much information as possible in a 7 min format while keeping it in a way that is easily understandable by people without an engineering background." you didn't do a good job. I teach aerodynamics to all ages (both as an engineer and as a CFI), and believe me, you're way will only confuse people or leave them with more questions. I can teach the engineering of such things to middle school kids and have them walking away with an intuitive understanding of such topics. Your video doesn't achieve that. If I asked someone who knows nothing, to watch your video, and then teach/explain it back to me, they'd fail miserably. "With that said, I’m pretty sure I know how winglets work as I have worked in the design of winglets in the past as well as consulted for the FAA on the effects of wake turbulence." you don't sound confident about that. But if you truly did understand how winglets work, you should have been able to draw the basic diagram that easily and visually explains to people how they work. But you didn't. Any discussion of winglets that doesn't include such a diagram is not an effective at teaching how they work.

[@lucasferrando-english4512]

Thank you for your feedback.