Effect of Wing Kinematics on Force Generation in a Beetle-Mimicking Flapping-Wing System

We have been developing a beetle-mimicking flappingwing system that can create a flapping angle of 140° to 160° and a rotational angle of 100° to 110°. Aerodynamic force is produced by flapping artificial wings, which are attached to the flapping mechanism by flexible hinges. In this study, we investigate the effect of wing kinematics on force generation by attaching the wings to the flapping-wing mechanism in three different configurations. Even though the flapping-wing system was designed to flap at about 40 Hz, in this study, it was excited at 25 Hz to maintain the quality of the signal process for force measurement. The average thrusts and lifts measured by a load cell were compared with those estimated by an unsteady blade element theory for the three cases. The results showed that the initial wing attachment angle significantly affected the wing rotation history during flapping motion and modified the magnitude of thrust and lift, as well as the direction of lift.