Aerodynamic Characteristics of a Twist Morphing Wing Consisting of Lattice Structures Evaluated by a Low-Speed Wind Tunnel

Twist morphing wings require both high bending stiffness and low torsional stiffness. To address this challenge, lattice structures are investigated because they can achieve anisotropic properties by rearranging the lattice shape. We developed a twist morphing wing made from a periodic cubic lattice. Although flight testing was successful, a quantitative aerodynamic evaluation was needed. In this study, a cubic-lattice twist morphing wing was wind tunnel tested at 10 m/s and angles of attack from −4° to 20°. First, to investigate the wing’s fundamental aerodynamics, the non-morphed state was compared to a polystyrene wing. The results showed that, despite slight differences, the overall aerodynamic characteristics were similar and the twist morphing wing’s lift-to-drag ratio was higher. Next, the aerodynamic characteristics were examined on the morphing wing. Twisting the wings asymmetrically generated lift differences between the left and right wings, like an aileron. Symmetrical twisting provided a flapping functionality, altering the aerodynamic characteristics over a wide range at the same attack angle without changing the aircraft’s attitude. These results quantitatively demonstrate that twist morphing wings made from cubic lattices can achieve aerodynamic performance comparable to that of rigid wings while enabling flexible and efficient alteration of aerodynamic characteristics through wing twisting.