Kinematic measurement and aerodynamic characteristic analysis of a flapping roatary wing

Complex motions of flapping rotary wing, and the interaction between kinematic and aerodynamic characteristics were studied using the experimental and computational methods. Based on a mechanical model of flapping rotary wing, wing motions and deformation were measured by photogrammetric experiments and digital image processing. Then, wing aerodynamic performance are analyzed based on the reconstructed motions using computational fluid dynamics method. The results are as follows: 1) The time course of flapping angle shows that flapping motion is like a triangular wave, the rotation angle increases linearly with time, and pitching angle exhibits dramatic variations around the initial angle of attack in a flapping cycle, with three peaks. 2)The time course of camber is like a triangular wave, phase displacement exists along spanwise. Torsion angle varies like a trapezoidal wave with time.3) Complex vortex ring is comprised by wing leading edge vortex, wing tip vortex and trailing edge vortex, vortex structures determine the instantaneous aerodynamic forces of the wing. 4) The wing deformation can significantly influence the aerodynamic performanceby increasing average and peak lift production.