No More Flaps???

NASA is testing a wing on a Gulfstream that changes shape in flight...

NASA successfully tests shape-changing airplane wings

 

Wright brothers did this 100 years ago!

 

Wing warping did not die out until around 1916 in Germany. Replaced rapidly with ailerons then. With very low landing speeds, no flaps required back then.

NASA has been working on shape changing wings for quite a while, but materials now are much better suited to doing that and EMAs and EHAs make the job much easier.

 

It looks like flaps under a wing skin.

 

My first though as well. Looks like someone came up with just the right stretchy material.

 

Air Force flew a Mission Adaptive Wing on an F-111 in the 80's. Had variable camber leading and trailing edges.

https://www.youtube.com/watch?v=Tm2YdbbLhYY

 

Changing the angle of incidence by twisting the outer portions of the wing, as the Wright Brothers did, is different than increasing the camber, as NASA is doing. Wing twist can be dangerous at low speed because too much twist will stall that part of the wing instead of lifting. The mechanical linkages to deploy slats and flaps and the separated high lift devices themselves would all be eliminated by the NASA design that would produce the same change in the camber.

 

I think there are still mechanical 'linkages', just not 'external' to the nominal airfoil shape of the wing, e.g. no more fairings. I wonder though of the real advantages at slow speed. It is well known that a slotted flap is more efficient than a plane flap due to the air moving through the slot is acting on an airfoil surface and also improves flow attachment over the flap surface. A plane flap, or even the NASA smooth TE will suffer from all the normal turbulent/separated flow on the aft 50% chord of the wing. The primary purpose of the MAW wing on the F-111 was not slow speed flight rather high speed maneuvering and cruise efficiency. It actually allowed negative camber, which has been shown to increase cruise efficiency at high speed.

 

Agreed, Jim. I was thinking about all the flap tracks, slat tracks, supports, and canoe fairings hanging outside of the wing.

 

Yes.

Seems like that would be a significant weight savings.

 

This is exactly right. The only change in technology here is the material between the augment and primary lifting airfoils. Nothing more shape shifting here than there is with conventional flaps. This is just putting a sports bra on some saggy boobs...they are still all saggy underneath! Underwhelmed...

 

AFTI F-111 wing, on the other hand...very nice project, and great video!

 

probably a re-post, but just stumbled on this
https://www.youtube.com/watch?v=8ZhMVG2W_QQ