Structural design and experimental verification of a novel split aileron wing

Many unmanned aerial vehicles (UAVs) such as solar powered ones require their top surfaces of the wings to be integral and gap free. To enable rolling movement and improve aerodynamic performance of such UAVs, a novel design scheme of split aileron is proposed that is similar to the concept of split flap. The function of the separated aileron is implemented utilizing an electro-servo system actuated by a brushless direct current motor (BLDCM). The design of three conceptual configurations, including the upper, middle, and bottom positions with deflection angle of 31° and 15° downwards, are studied numerically. Based on the optimal design of the bottom position of the split aileron structure, its aerodynamic characteristics, maneuverability and structural weight are evaluated by comparing with a traditional hinged aileron. The results indicate that the proposed design of the detached aileron can enhance the average aerodynamic efficiency of the wing by 16.3% and reduce the weight by 58.3%. A functional prototype of the split aileron wing airplane is established and manufactured based on the proposed design. The flight test results confirm the applicability of the clam-shell aileron to control the rolling motion of aircraft, which is of high potential for solar-powered fixed-wing UAVs.