Wind tunnel testing is a technique that aerodynamic parents have long used to directly measure forces, moments, pressures, and visualize airflow conditions in aircraft design. Airlines typically design and build special small-size aircraft models for wind tunnel testing, but this task may not be easy. Italian company Leo nardo SpA (formerly Finmeccanica) used to make models from wood, metal and traditional composite materials, but using traditional materials and processes to make models takes a lot of time and energy, especially when engineers want to design When making changes.
The Leonardo Helicopter Business Unit (formerly AgustaWestland) needed a new 1: 8.5 scale AW609 tilt-rotor aircraft for a series of standard flight attitudes at the company's own wind tunnel laboratory and its factory in Politecnical di Milano Dedicated low-speed flight test. In addition, engineers want to be able to freely and quickly change the external geometry of the model to understand its aerodynamic performance. In order to achieve this goal, Leonardo cooperated with Italian metal tech Srl and used 3D printed materials of Italian CRP Technology under the trademark Windform.
According to Leonardo's CAD design files, metaltech uses aluminum alloy and steel to construct an internal structural skeleton. CRP Technology uses Windform XT 2.0 carbon fiber-reinforced polyamide composites, and uses selective laser sintering (SLS) 3D printed models of fuselage and nose components, fairings, nacelles and spinners, rear wings, wings and flaperons, To match the metal skeleton. Windform XT 2.0 composites meet Leonardo's requirements for rapid production, high stiffness, high elongation at break, good dimensional tolerances, and detailed reproduction. Windform materials have demonstrated sufficient resistance to wind load deflection in structural strength tests under expected load conditions.
CRP Technology said that because the design dimensions of some parts are beyond the scope of 3D printer construction, they must be manufactured in stages. Based on the CAD file, the segmented parts are designed according to the wind tunnel tunnel conditions and the pressure that the parts may be subjected to without increasing production time and costs. The 3D printing process is completed within four days. The parts are waterproofed and spray-painted and delivered to metaltech for assembly on the metal skeleton structure.