Changing the shape of wing design using "digital materials"
Though we're used to airplane wings with moving flaps that control
the craft's movements, the first flying machine built by the Wright
brothers in 1908 used a different technique called wing warping.
Instead of tilting airfoils attached to the trailing edges of wings,
warping uses wires and pulleys to alter the shape of wood and canvas
wings to perform the function that ailerons and flaps do in modern
airplanes.
According to the NASA/MIT team, there have been numerous attempts to
revive this technology, but these have relied on mechanisms inside
the wing to bend it. The problem has been that this machinery usually
turns out to be too heavy and complicated, which offsets any
increases in aerodynamic efficiency.
A newly developed wing architecture could greatly simplify the
manufacturing process and reduce fuel consumption by...
The NASA/MIT approach is to not just do away with the internal
mechanism, but to fundamentally redesign the structure of the wing so
it is capable of bending by itself. The design achieves this by
dividing the wing into lightweight, overlapping scale- or
feather-like sub-segments. These are supported by tunable and
actively deformable modular building blocks, dubbed "digital
materials," that are made of carbon fiber-reinforced polymers that
can be quickly engineered and snapped together and allow the wing to
deform while maintaining a smooth, aerodynamic surface.
This modular approach would allow the individual support pieces to
be mass produced and combined in an almost endless variety of shapes,
which could be constructed by simple minature robots that crawl along
the exterior or even the interior of the structure as it is
constructed. Though the researchers have already developed prototype
robots, they built the initial test structure by hand and used skin
panels instead of scales that would be used the ultimate version.
The units used were morphed manually using two small motors to twist
the wingtips and bend the wing uniformly along its entire length. The
purpose of this test piece was to get the wing to twist in the same
manner as if it was made of separate scales instead of panels by
fine-tuning the structure so it twists on command into the desired
aerodynamic shape.
So far, wind tunnel tests have shown the test wing has aerodynamic
properties of a conventional wing weighing 10 times more. The team
then built a drone aircraft flown from the ground by a certified test
pilot, who found it responsive enough to do aerobatics.
Gershenfeld sees this technology as not only leading to
super-efficient long-range drones, but as having applications beyond
aerospace engineering, inlcuding in wind turbines, skyscrapers,
bridges, and space structures. It could also be used to create soft
robots that can bend wherever desired without joints, are lighter
than equivalent robots, yet can maintain the desired level of
stiffness for the job. Repairs of machines built with the units would
be cheaper and easier as damaged units could be replaced by
maintenance robots with new ones.
MIT <
http://news.mit.edu/2016/morphing-airplane-wing-design-1103
View gallery - 5 images
John Dinkel
Where are the puns? :-)
Paul Lamar
Paul, On an even less punishing note. A I read these advances in
aero, I think to myself that we are on the cusp of our ability to
control and develop materials that will take us to the stars. Can
our control of gravity, magnetism and dark matter be that far in the
future? Maybe 10 years????
Or maybe we’ve had much of this tech since Roswell . . . John Dinkel
IMHO all the space stuff is a huge waste of money.
Paul Lamar
Paul, I agree. This is a bit of a waste of money in my opinion. Too
much technology is too much. If we keep up at this pace we will be
living on a planet that looks like the death star not too long from
now. LOL
At least the wings have the "cool" factor I guess.
End of unnecessary 2cents
jenn kimball
NASA/NACA had a good program going on the rotary as an aircraft
engine awhile back. That went by the wayside when they got involved
with all this space stuff.
The third temperature chart is of interest right now and is relevant
to the steel rotor housing air cooled one rotor. This is from an IAA
paper back in 1984.
Paul Lamar
Hi Paul, I would have thought that the easiest way to warp a wing
would be like the Ivo prop. The wing itself would need to be
composite of course with the fibre orientation in the appropriate
direction. Chris Hoskins
The IVO prop has a thick steel tube in side that applies the twist
to the outer section. scaled up to wing size it would be heavy.
However a carbon tube about the diameter of the wing thickness might
be viable. If it could take the place of a spar that would be even
better. Two ball bearing on the tube where it goes into the fuse
would be required to take the "spar" bending loads. Is it worth
replacing the ailerons?
I doubt it. The up side wing would be more drag anyway due to lift
while a properly designed aileron on the down side has a feature that
adds drag to the lower wing that makes the turns coordinated with out
the need for rudder.
The Wright brothers discovered this and added a rudder control to
compensate.
The bottom of the down side aileron on the C182 catches air causing
drag on that side automatically compensating for the tendency to yaw
counter to the desired turn.
You can see it in this picture.
I will copy the Cessna 182 wing exactly in carbon if I build my 200
MPH STOL bush plane with retractable balloon tires. The C182 is
already a pretty good bush plane except for the landing gear.
My C182 flies great with perfectly coordinated turns and I never
have to touch the rudder pedals unless I am slipping it in :-)
Paul Lamar
The reason that wing warping has fallen out of favor is that it only
works well on slow airplanes. At higher velocities the forces necessary
to control the aircraft become unmanageable using wing warping.
Ailerons are much more effective with far less control force being
required because the hing moment of the ailerons can be engineered such
that the airflow can be used to assist in the actuation of the control
surface. Wing warping does not offer such advantages.
Perhaps with the new fly by wire aircraft that are totally controlled by
computers using hydraulic/electric servos the heavy control forces might
not matter since none of the power to move the control surface actually
comes from the pilot's muscles.
Mark LaPierre
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