High wing strut braced... airliner?

[Gnarly Gnu]

"

 

[/url]NASA is developing a stiletto-like plane wing

 

that's so long and thin that it needs a truss to hold it up. The longer, thinner, and lighter truss-braced wing, as it is called, is aimed at making future commercial transport aircraft more efficient and less polluting."

 

 

 

 

 

 

 

 

 

 

A broader flat-bottomed lifting fuselage might help too... well let's hope it uses a lot less fuel because it has a lot less available storage space for said fuel.

 

 

 

Hey who'da thought, they've sort of reinvented the Jabiru.

 

 

 

 

 

 

[cooperplace]

is it high wing just because the strut thing works that way? Or is there some efficiency that flows from high wing?

 

 

[mnewbery]

The vertical location of the wing relative to the fuselage has no effect on the performance of the wing or the fuselage IN CRUISE. This is a general statement of course.

 

Where the location of the wing has an effect on the inside of the fuselage is in the carry-through or wing box. A slender (actually "fine") wing attached as a cantilever would have a huge torque at the wing root and subsequent huge wing box. This might eat into the payload area even if it is in the roof.

 

The strut brace can address this issue while also providing a utility path for things like wires and fluid lines. It can also provide a bit of dihedral while managing the wing flex. The inside of the wing can become a lot more simple as a result. Metal works better in tension so it makes sense to put it on the bottom of the wing.

 

It still looks like a cop out to me.

 

 

[Gnarly Gnu]

Or is there some efficiency that flows from high wing?

Check out a bird carefully next time you see one.

 

 

[Marty_d]

Low winged birds would fly equally well, but I would say the wing position is more to do with the evolution of the upper limb (ie position of the shoulder joint in relation to ribcage and spine) than optimal flight characteristics. There's no reason a low-winged bird wouldn't fly, it just wouldn't evolve that way.

 

 

[cooperplace]

Check out a bird carefully next time you see one.

I know that all birds have high wings. I've yet to hear a good explanation for this.

 

 

[Marty_d]

I know that all birds have high wings. I've yet to hear a good explanation for this.

See Birds: The Late Evolution of Dinosaurs | Natural History Museum of Los Angeles

 

Then see picture below.

 

 

Birds have a deep chest with a keel at the bottom. Why?

 

 

Because they need that to hold the muscles used for flapping the wings.

 

Now imagine all that going on top of the bird, instead of under. Either the chest would be above the backbone (so the bird is flying upside down with its head and hips twisted 180 degrees), or the keel would need to be above the spine, instead of an extension of the existing sternum. Neither of these is the easiest way to evolve from a land based dinosaur to a flying one, so it didn't happen.

 

Most passenger aircraft are low wing. I'm sure if there was an compelling efficiency dividend for high-wing then Boeing and Airbus would've switched long ago.

 

 

[pylon500]

All the efficiency they gain from the higher aspect ratio wing (which is all it is), will be lost in the biplane interference caused at the strut junction, to say nothing of the section buildup created by the straight strut.

 

NASA, well, I think mainly their students, are coming up with a lot of ideas lately, that don't really make a lot of sense, or miss obvious (counter) explanations that have been known for years.

 

There was a lot of work (and money) spent on trying to prove some nineteenth century bird watchers theories about winglets and like, which I found on youtube;

 

They were trying to prove that a flying wing can be efficient, but really, all it proved was that higher aspect ratio wings are more efficient aerodynamically.

 

Don't get me wrong, I like flying wings, but the compromises involved in getting them as efficient as a 'normal layout', mean dealing with some pretty serious stability problems.

 

It might be OK today what with autonomous artificial stability and stuff, but get it wrong in an airliner, and it'll suddenly turn into a cloud of composite bits and bodies hurtling through the sky....

 

 

[Deskpilot]

Great video Pylon, thanks.

 

 

[facthunter]

I always reckon a flying wing could turn into one of the biggest bullroarers around. Birds use their heads feet and tail for stability. Their feathers work as slats. Very efficient. The albatross can lock it's bones in the wing to give the muscles a rest. ALL birds have a largish breastbone to anchor the muscles/ tendons to, so structurally they resemble a hiwing with struts, but the struts are internal

 

Besides perhaps being too rigid the struts are so inefficient aerodynamically and complicate high subsonic design I can't see this applying to anything that wouldn't use a turboprop engine back at Mach .5-6. Nev

 

 

[Jabiru7252]

I'm still waiting for engines that are not based on 70 year old technology. Where's the 'boom-shaker mark one' warp drive I expected by year 2000?

 

 

[Downunder]

I'm still waiting for engines that are not based on 70 year old technology. Where's the 'boom-shaker mark one' warp drive I expected by year 2000?

Coming soon (2066?) to an aero engine near you. Variable compression ratio.....

 

Infiniti's latest engine is a last hurrah for gas-powered cars

 

Well, at least cars are moving forward in engine technology........

 

 

[facthunter]

There's a limited application of automotive to aero. Most of the time a car engine is operating at quite low power settings. The aero engine needs boosting to operate at heights. Nev