Induced drag analysis of multi-winglets for aerodynamic performance on NACA 23015 / Zaim Ariefin Azwan Affendi Nual

An eagle can reach high velocities and stay airborne for hours. It is believed that the capability of an eagle to do so is due to the multi-winglets during its gliding and soaring flight without flapping its wings. Multi-winglets as a device for reducing induced drag in unmanned aerial vehicles (UAVs) was tested through a simulation study. The usage of multi-winglets as a wingtip device is inspired by the bald eagle that is an exceptionally efficient creature in terms of aerodynamics. The objective of this research is to study the aerodynamic effect of implementing multi-winglets on UAVs in terms of induced drag and lift coefficient. The design of 3 different multi-winglets based on NACA 23015 was computationally modelled. The winglet design with chord length (C) of 216.5 mm, 866 mm wingspan (L) and angles of attack of -5°, 0°, 5°, 10°, 15°, 20° were improvised with multi-winglets of differing amounts at 3 multi-winglets with cant angles of 15° between each winglet, 5 multi-winglets with cant angles of 7.5° between winglets and 7 multi-winglets with cant angles of 5° between each winglets. The three multi-winglet models and the baseline were tested at Unmanned Aerial Vehicles (UAVs) flying speed at 30 m/s with the boundary condition of air temperature at 293.3 K. The investigation has shown that the multi-winglets can improve the aerodynamic performance of airfoil in reduction of induced drag and increase of lift coefficient.