Development of a Flapping Wing MAV Based on an Efficient Design of a Wing with Twist

Abstract

In this paper wing of an ornithopter has been designed with specific twist distribution that results generation of substantial net positive lift and thrust over a cycle at non-zero advance ratio. The wing has a specific but different twist distribution during the downstroke and the upstroke that maintains the designed angle of attack during the strokes. The wing is divided into spanwise strips and Prandtl’s lifting line theory is applied to estimate aerodynamic forces. Quasi-steady assumption is made to estimate the forces when wings are without any dihedral or anhedral. The forces estimated using this theory is expected to reduce with dihedral or anhedral and hence a factor of safety is used in the design. The novelty of the present wing design is the appropriate spanwise geometric twisting about the leading edge spar axis. A prototype is developed based on the above predictions which successfully flew.