SULSA is the world’s first “printed” aircraft. Credit: University of Southampton |
Engineers
at the University of Southampton have designed and flown the world’s
first ‘printed’ aircraft, which could revolutioniZe the economics of
aircraft design.
The
SULSA (Southampton University Laser Sintered Aircraft) plane is an
unmanned air vehicle (UAV) whose entire structure has been printed,
including wings, integral control surfaces and access hatches. It was
printed on an EOS EOSINT P730 nylon laser sintering machine, which
fabricates plastic or metal objects, building up the item layer by
layer.
No
fasteners were used and all equipment was attached using ‘snap fit’
techniques so that the entire aircraft can be put together without tools
in minutes.
The
electric-powered aircraft, with a 2-metres wingspan, has a top speed of
nearly 100 miles per hour, but when in cruise mode is almost silent.
The aircraft is also equipped with a miniature autopilot developed by Dr
Matt Bennett, one of the members of the team.
Laser
sintering allows the designer to create shapes and structures that
would normally involve costly traditional manufacturing techniques. This
technology allows a highly-tailored aircraft to be developed from
concept to first flight in days. Using conventional materials and
manufacturing techniques, such as composites, this would normally take
months. Furthermore, because no tooling is required for manufacture,
radical changes to the shape and scale of the aircraft can be made with
no extra cost.
This
project has been led by Professors Andy Keane and Jim Scanlan from the
University’s Computational Engineering and Design Research group.
“The flexibility of the laser sintering process allows
the design team to re-visit historical techniques and ideas that would
have been prohibitively expensive using conventional manufacturing,” says Scanlon. “One
of these ideas involves the use of a Geodetic structure. This type of
structure was initially developed by Barnes Wallis and famously used on
the Vickers Wellington bomber which first flew in 1936. This form of
structure is very stiff and lightweight, but very complex. If it was
manufactured conventionally it would require a large number of
individually tailored parts that would have to be bonded or fastened at
great expense.”
“Another design benefit that laser sintering provides is
the use of an elliptical wing planform,” says Keane. “Aerodynamicists have, for
decades, known that elliptical wings offer drag benefits. The Spitfire
wing was recognized as an extremely efficient design but it was
notoriously difficult and expensive to manufacture. Again laser
sintering removes the manufacturing constraint associated with shape
complexity and in the SULSA aircraft there is no cost penalty in using
an elliptical shape.”
SULSA
is part of the EPSRC-funded DECODE project, which is employing the use
of leading edge manufacturing techniques, such as laser sintering, to
demonstrate their use in the design of UAVs.
The
University of Southampton has been at the forefront of UAV development
since the early 1990s, when work began on the Autosub programme at its
waterfront campus at the National Oceanography Centre, Southampton. A
battery powered submarine travelled under sea ice in more than 300
voyages to map the North Sea, and assess herring stocks.
Now,
the University is launching a groundbreaking course which enables
students to take a Master’s Degree in unmanned autonomous vehicle (UAV)
design.
This
is the first scheme of its kind and from September 2011, postgraduates
can take part in a one-year program covering the design, manufacture
and operation of robotic vehicles. The degree will cover marine, land
based and pilotless aircraft, typically used in environments that are
deemed unsafe or uneconomic, such as exploration under sea ice, or
monitoring gas emissions from volcanic eruptions. NASA expects UAVs to
become ‘standard tools’ in fields such as agriculture, earth observation
and climate monitoring.
