ecomodding commercial airplanes

[some_other_dave]

Originally Posted by Piwoslaw

Can any plane be retrofitted with those winglets?

Many can be, as far as I know-- BUT:

- They need to have "type approval" or be FAA certified as a modification. This can be a lengthy and expensive process.
- Wings with round tips will make adding winglets difficult.
- Low-speed aircraft may not benefit much from them.
- Supersonic aircraft may have other constraints.
- Military aircraft may have other constraints (e.g., low-observable "stealth" configurations, room for wings to fold for storage on board ship, etc.).

I only really can recall seeing winglets on aircraft with swept wings that also taper. It is possible that other wing forms create difficulties with adding them or with their effectiveness. But on most airliners, I would think they would be a good addition. Assuming they get approved, of course.

-soD

[euromodder]

Originally Posted by Piwoslaw

Can any plane be retrofitted with those winglets?

You'll find winglets on anything from low speed, straight-wing gliders to high subsonic swept wing commercial aircraft.
So yeah, just about any subsonic aircraft can use them.
Supersonic winglets and the like are still being researched.

Boeing, Airbus and some aircraft industry suppliers are introducing retrofit kits to keep older planes economically viable.

[Vman455]

I noticed Boeing started using winglets in the 90s, like on the redesigned 737s:



(737-800, entered service 1998, according to Wikipedia)

...and the 747-400:



But the 787 eschews them!



...and so does the new 747-8:



And all the press renderings of the upcoming 737 redesign show conventional winglets:



Or what look like a funky version of Airbus's winglets:



What gives? Why do designs from one company use them, then stop using them, then possibly use them again?

[orange4boy]

Boeing is making a big claim on those winglets: 5.5% better FE!

Boeing's New Double-Edged Winglet Saves Gas, Looks Awesome || Jaunted



The trailing edge on those turbofans looks pretty cool too. Are those VGs for noise reduction? Why yes, yes they are:

A jet engine noise reduction device called a chevron, now in use on commercial airliners, is a good example of a NASA-developed technology that climbed the TRL scale to success, said Fay Collier, manager of NASA's Environmentally Responsible Aviation Project.

Chevrons are the saw-tooth pattern that can be seen on the trailing edges of some jet engine nozzles. As hot air from the engine core mixes with cooler air blowing through the engine fan, the jagged edges serve to smooth the mixing, which reduces turbulence that creates noise.

The new Boeing 787 is among the most modern jets relying on chevrons to reduce engine noise levels, sporting chevrons on the nacelles, or fan housings. The Boeing 747-8 has chevrons on both the nacelles and inner core engine nozzles.

They under describe them a bit. I found elsewhere that they are, in fact VGs. So all you trailing edge VGers can now claim that your VGs are really, actually, for noise reduction.

From:Aerospace Technology: Technology Readiness Levels Demystified08.20.10

Also they are working on air injection VGs for noise reduction:Fluidic Chevrons for Jet Noise Reduction