Engineers have flown the world's first 'printed' aircraft and say it could revolutionise aircraft design economics.
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.
Engineers at the University of Southampton printed the aircraft with an EOS EOSINT P730 nylon laser sintering machine, which fabricates plastic or metal objects and builds them up layer by layer.
“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,” said Professor Jim Scanlon of the university’s Computational Engineering and Design Research group, who co-led the project with colleague Professor Andy Keane.
“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.”
Laser sintering allows the designer to create shapes and structures that would normally involve costly traditional manufacturing technique, allowing a highly-tailored aircraft to be developed from concept to first flight in days.
Using conventional materials and manufacturing techniques, such as composites, would normally take months.
The team used a Geodetic structure which is very stiff and lightweight but also very complex, Professor Scanlon added.
This type of structure was first developed by Barnes Wallis and used on the Vickers Wellington bomber.
“Another design benefit that laser sintering provides is the use of an elliptical wing planform,” said Professor Keane.
“Aerodynamicists have known for decades that elliptical wings offer drag benefits.”
He cited the example of the Spitfire wing, which was recognised as an extremely efficient design but 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,” he said.
All equipment was attached using ‘snap fit’ techniques rather than fasteners, allowing the entire aircraft to be put together in minutes.
The electric-powered aircraft, with a 2-metre wingspan, has a top speed of nearly 100 miles per hour, and is also equipped with a miniature autopilot.
Radical changes to the shape and scale of the aircraft can also be made with no extra cost as no tooling is required for manufacture.
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.
The university is now launching a Masters' Degree course in unmanned autonomous vehicle (UAV) design, which it says is the first scheme of its kind.
It 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 has said it expects UAVs to become 'standard tools' in fields such as agriculture, earth observation and climate monitoring.