| A study has been conducted to optimize the aerodynamics of a solar powered unmanned aerial vehicle for low Reynolds number flight. In this study, three areas of the airframe, namely the fuselage, wing-fuselage junction and wingtips, were analyzed, tested, evaluated and developed in an iterative design process. A numerical analysis method was employed to complete the aerodynamic study, the purpose of which was to minimize adverse flow conditions occurring near or about the aforementioned areas under most flight conditions and to maximize their aerodynamic usefulness. The results were benchmarked internally through the iterative process using the initial design as a control and externally by comparing with collected empirical figures characterizing solar airplanes of the past and present. The results showed that with careful design practices, wingtip devices can be made to improve flight characteristics at low Reynolds number flight significantly enough to offset their structural disadvantages, providing a substantial drag decrease over the entire flight envelope. It was also shown that fuselage shape can be modified to accommodate the airplane's mission and fulfill a greater role than solely being a payload carrier by using this body to generate and control aerodynamic forces. Finally it was illustrated that careful design of the wing-fuselage junction could lead to significant improvements in both lift and drag characteristics. |
