Impacts of Tapered Wingtip on Lateral-Directional Stability Coefficients of a Morphing Fixed-wing UAV

Recent developments in unmanned aerial vehicle (UAV) technologies have shown the possibility of morphing applications to provide improvement in various performance metrics in the desired manner. In rotary-wing UAVs, applications mainly focused on propeller blades and rotor arms, while efforts on fixed-wing UAVs mainly concentrated on the main wing and tail geometries. Although every morphing design has its own advantages and disadvantages, all of the applications have similar common purposes to have improved aerodynamics, flight performance, control responses, or a combination of such objectives. In that context, new morphing design attempts require a precise investigation of their pros and cons. Thus, in this study, a new morphing scenario of tapering morphing wingtip is applied to ZANKA-I fixed-wing UAV and investigated in terms of lateral-directional stability considerations. The lateral dynamic model of the aircraft is constituted and necessary aerodynamic, geometric, and inertial assessments are numerically and analytically performed. The lateral-directional stability coefficients are discussed and an improvement in lateral stability is obtained, while directional stability is found to be affected negatively by the morphing application.