Influence of Layer Thickness on the Design of Rapid-Prototyped Models

Today, engineers are aiming for performance, quality, and repeatability, to be reached in a very short delivery time. Rapid-prototyping techniques are applied to concept design and modeling. A typical aircraft development program usually needs at least four to five wind-tunnel models to adequately test the aerodynamics of a new airframe. The models are generally made of steel or aluminum. The models can require months to be manufactured. The dimensional accuracy, surface finish, and strength of such all-metal models have a distinguished history of providing high-fidelity aerodynamics data for both subsonic and supersonic aircraft. However, the fabrication of all-metal wind-tunnel models is very expensive and time-consuming. This paper describes the effects of layer-thickness models on aerodynamic coefficients to construct wind-tunnel-testing models produced with rapid prototyping. These models were fabricated from SOMOS NanoTool by stereolithography. The layer thickness for each model was 0.025, 0.05, and 0.1 mm. Testing covered the Mach range of Mach 0.10 to 0.40. Results from this study show that layer thickness does have an effect on aerodynamic characteristics. The layer thickness is more effective on the aerodynamic characteristics when Mach number is decreased and has the most effect on the aerodynamic characteristics of axial force.