Abstract
We studied the optimum flapping wing motions of a dragonfly (Anax parthenope julius) from hovering to cruising flight at various speeds, using a 3D Navier-Stokes code coupled with an optimization algorithm. The minimum necessary power curve and optimum flapping wing motions for the various flight velocities were determined using the optimization algorithm. The minimum power curve shows the typical U-shape. The optimum flapping wing motions were evaluated by comparison with experimental data. Examining the flow patterns showed that the large-scale flow separation around the wings is suppressed at these optimum conditions, except for very low flight speeds including hovering.
