Wind tunnel testing of an avian-inspired morphing wing with distributed pressure sensing

Small fixed wing uncrewed air vehicles (UAVs) are often required to fly at low speeds and high angles of attack, particularly when operating in urban environments. This study focuses on the potential of combining two bio-inspired flight technologies to improve maneuverability under these conditions. The outstanding flight agility of birds is believed to be enabled by the capability to sense the airflow over their wings and morph their wing surfaces accordingly. To test the benefits of combining these abilities a wind tunnel model able to perform an avian-inspired wing sweep motion incorporating two arrays of pressure sensors was developed. Aerodynamic load results highlight strong changes to the pitching moment produced by the change in wing sweep angle. This suggests that wing sweep can be an alternative or complementary mechanism for pitch attitude control, improving control authority at high angles of attack. On the other hand, pressure sensing data shows the ability of these sensors to detect the fine details of the onset of aerodynamic stall. The combination of these two novel technologies is suggested as a potential method to improve UAV pitch control when flying at low speeds, when the aircraft is most susceptible to environmental disturbances.