Airbus Albatross 1

[rb1957]

If you haven't read, this is an Airbus project where they looking to reduce the gust loads on the wing by hinging the outbd panels.

"they" (ie the industry) have tried this in the past. Gust load alleviation to improve something (maybe reducing cabin/passenger turbulence, maybe improving cruise performance, maybe reducing structural weight) has the unfortunate side effect of reducing crack growth retardation (by reducing the gust overloads).

Admittedly this is with Al wings, and now they've gone composite maybe the lesson is different ? But it worries me when they try to remove weight in the primary structure … I'd look for weight gains in the secondary structure, interiors, and systems. But then I'm a structures guy (not a systems guy).

another day in paradise, or is paradise one day closer ?

 

[VEBill]

Flight Global

It's usually a good thing to have a suspension system, in between the vehicle and its medium of support.

Bypassing gusts should make things better overall, until the structure is removed to cash-in for weight savings. Maybe they'll split the difference.

For carbon fiber structures, it should be "simple" (not really) to embed fine insulated wires into the structure to detect and locate significant cracks. It's easy (sort of) to use RF sweeps to measure the length of a wire, thus making breaks detectable by the change in length.

 

[Sparweb]

I couldn't tell from the article if the wingtip, when unlocked, is limited by an actuator of some sort, or else what would stop the wing tip from dragging on the ground?
Possibly a variable damper would be the thing to use, or something like an oleo strut whose valve can be shut to make it lock.

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

 

[rb1957]

I thought the difference (to the B777 fixed wingtip) was that the Airbus wingtip is driven. I guess it could be free to move (in cruise), maybe with limiting stops, maybe with dash-pots to limit/control the movement, and with some control to return it to a locked position for landing.

another day in paradise, or is paradise one day closer ?

 

[3DDave]

At first I was thinking A380.

I don't see how this would make much difference to passengers. It would be far less than a 25% reduction in response if the entire wingtip vanished for the gust duration. However, that part of the wing is not supplying a full 25% of the lift. It's also behind the Cp so there would be a pitch component as well - recalling the adage that "pitch makes you puke" - it doesn't seem like a great idea.

The locking, folding wingtip for gate clearance combined with aspect ratio seems like a usable idea, but an aeroelastic surface does not. Keep in mind that an actual albatross has a large number of muscles (actuators) to alter the pitch of the outer wing and that so far there have been no similarly effective actuators.

 

[rb1957]

yeah, I thought Albatross was a bad name (though a good WW1 plane). Wonder if you'd be better articulating the "normal" winglets/sharklets ? As B737 has added more elements, why not moving elements ?

another day in paradise, or is paradise one day closer ?