Multi-Disciplinary Analysis and Design Optimization of a 3D Model Airplane

The SAE Regular Class Aero Design Competition requires students to design a model scale aircraft with limits to the power consumption, take-off distance, and wingspan, while maximizing the amount of payload it can carry. As a result, the aircraft should be designed subject to these simultaneous and contradicting objectives: 1) minimize the drag, 2) minimize the pitching moment, and 3) maximize the lift. This study aims to determine five optimized geometric design variables: 1) incidence angle of the wing, 2) incidence angle of the horizontal tail, 3) distance between the wing and the tail, 4) sweep angle of the winglets, and 5) height of the winglets. To determine the incidence angles, an airplane was initially designed using the highly cambered S1223 airfoil for the wing and the inverted NACA2409 airfoil for the tail. The same fuselage shape was used for all configurations where the only changes were the incidence angles and the distance between the wing and tail. Wing incidence angle was varied in the range 0° to 10°. Tail incidence angle was varied in the range -5° to 0°. Horizontal distance between the wing and the horizontal tail was varied in the range 4L to 10L, where L is the wing chord length. Each random combination of the design variables defined its own 3D aircraft configuration. Aerodynamics of each of these 3D aircraft shapes including their coefficients of lift, drag, and pitching moment were calculated using ANSYS Fluent software. Fourty such aircraft configurations were analyzed before the results were inputted into modeFrontier software to perform the multi-objective optimization study resulting in a Pareto-optimized set of the best trade-off 3D airplane geometries having the best combination of incidence angles and the wing-tail distance to achieve the three stated goals. Structural 3D analysis and static and dynamic stability analyses were also performed