When Leonardo HD wanted to test the aerodynamic soundness of its AW609 tilt-rotor aircraft, it tapped CRP Technology to create a 3D-printed model of the aircraft to run wind tunnel tests.
CRP created a 1:8.5 scale replica of the aircraft by using selective laser sintering to create parts of the model—nose and cockpit, rear fuselage, nacelles, external fuel tanks and fairings. The parts were made out of CRP’s Windform XT 2.0 carbon-composite materials. This material, used extensively in the motorsports industry, features high heat deflection and stiffness that makes it ideal to withstand the aerodynamic loads simulated during wind tunnel testing.
Wind tunnel models are commonly made with conventional composite materials—which can take quite a long time to manufacture. Leonardo used to make them out of wood and metal; now, however, CAD plays an essential role in their production. An internal structural aluminum and steel frame was milled and assembled, and the 3D-printed components were attached to it via a specialized rig. The time saved was significant: individual parts could be made in about a day, and all the pieces of the model were created in four manufacturing days.
The planemaker chose to use a 3D-printed model for several reasons: it delivered consistently high reliability and commonality of parts in a short testing and development timetable and it accelerated the development of new composite materials with the aerodynamic performance of established composites. In addition, it helped engineers design and manufacture an internal main structure that could easily incorporate new parts to test potential upgrades for existing aircraft—or to develop future products.
The 1:8.5 scale model was put into a wind tunnel to conduct a series of low-speed tests of a standard range of flight attitudes at the planemaker’s wind tunnel facility and at Politecnico of Milan. After those tests were completed, a 1:6 scale model was created for high-speed testing at the NASA Ames wind tunnel facility.
Using 3D printing and advanced composite materials has helped accelerate the development timeline of the AW609, which the company anticipates will receive U.S. certification this year. Successes like this will only encourage more adoption of these technologies in the aerospace sector.
Read more about additive manufacturing in the aerospace industry at 3D Printing the World’s Largest Single-Piece Rocket Engine.