Covert-Inspired Flaps as Flight Control Devices During Dynamic Pitching Maneuvers

Small-scale Uncrewed Arial Vehicles (UAVs) have become increasingly important for both civil and military operations over the past decade. However, their flight capabilities remain limited during demanding maneuvers such as landing, takeoff, and high-pitch rate maneuvers. In contrast, birds perform similar maneuvers with relative ease, partially due to feather systems, such as covert feathers. Previous research by the authors has demonstrated that covert-inspired flaps can be used for flight control in steady-state flight conditions. This study expands our understanding of covert-inspired flaps as flight control devices by examining their effectiveness during dynamic pitching maneuvers. We conducted wind tunnel experiments and measured the aerodynamic forces and moments along with the velocity and vorticity field using time-resolved Particle Image Velocimetry (PIV) on a two-dimensional wing section with covert-inspired flaps mounted on the suction and pressure sides. Results quantify the effectiveness of covert-inspired flaps during a dynamic versus static flight maneuver. Our findings are further supported by data-driven models, and we provide recommendations for the implementation of these flaps on UAVs.