BIRD-INSPIRED MORPHING WINGS: DESIGN AND EXPERIMENTAL EVALUATION OF A WING FOLDING MECHANISM FOR PITCH STABILITY CONTROL

Birds can land quickly and in confined spaces while maintaining control over their descent rate and location. In contrast, many bird-scale, unmanned aerial vehicles (UAVs) must land in a net, be caught by hand, or require a long runway for roll-out. Inspired by bird wings' geometry during short-distance landing or perching, this study investigates the aerodynamic performance of two M-shaped wing configurations. The M-shaped configurations represent different stages of the pitch-up phase during perching. Results from wind tunnel experiments of a simplified engineering wing show that the M-shaped wing configurations improve aerodynamic efficiency at high angles of attack by more than 80%. The results confirm that the M-shaped configurations aid in creating a pitch-up moment, and when deployed asymmetrically, the M-shaped wings can be used for roll and yaw control.