Investigation of the Structural Deformations of Various Plastic Spoilers with NACA 6409 Cross Section at Subcritical Reynolds Numbers under Different Angles of Attack

This study investigates the aerodynamic performance and structural deformations of finite rectangular planform wings with a spoiler with a NACA 6409 airfoil section, fabricated from 3D-printed plastic materials. Unlike conventional aluminum or carbon fiber spoilers, plastic components with a high aspect ratio exhibit more pronounced aeroelastic effects, making their characterization important for practical applications. The main objective was to evaluate aerodynamic loads and resulting deformations through both experimental wind tunnel testing and numerical simulations. Wings with dimensions of 100 × 400 mm were fabricated using additive manufacturing techniques (MJF and SLS) with Nylon PA12, Resin CUV9400, and Nylon PA12GB materials. Tests were conducted at uniform wind speeds up to 30 m/s and varying angles of attack. Results show that the maximum Y displacement occurred at 10° and 30 m/s, with values of –51.03 mm for Nylon PA12, –26.52 mm for Resin CUV9400, and –21.73 mm for Nylon PA12GB. The maximum von Mises stress reached 10.7 MPa, 10.9 MPa, and 11 MPa for the three materials, respectively. Numerical simulations showed close agreement with experiments, with deviations below 6% for deflection and 4.37% for torsion. In conclusion, Nylon PA12GB demonstrated superior performance due to its lower deformation, confirming its suitability for cost-effective and lightweight aerodynamic applications.