Flapping wing performance related to wing planform and wing kinematics

Abstract

In the quest for energy efficient flapping wing micro air vehicles (FWMAVs), the wing performance is of paramount importance. The wing performance is mainly determined by the wing planform and the wing-beat kinematics. Since the optimization of the wing planform and the wing-beat kinematics is complicated by the flapping wing aerodynamics, most FWMAV designs tend to use standard wing planform and kinematics inspired function of the wing planform and the kinematic pitching amplitude. For this purpose, a quasi-steady aerodynamic model is used to determine the aerodynamic loads. This model allows, opposed to the more computationally costly method of direct numerical simulation, its use in optimization. The average normalized lift force, the average normalized required power and the ratio between those two are visualized as a function of the design variables to define the required wing planform and pitching amplitude for optimal hovering performance. Using different optimization formulations, it was found that several different wing designs result in nearly equal performance. It is shown that there is a lot of design freedom with respect to the design variables. This freedom is also shown in nature by the presence of a huge variety of wing planforms.