Rotor and Airfoil Design for Efficient Rotary Wing Micro Air Vehicles

Rotary wing Micro Air Vehicles (MAVs) are especially well suited for a broad range of missions that fixed wing MAVs cannot accomplish. A robust agile vehicle with efficient rotors is required to make this configuration practical. The current investigation explores the influence of a series of parameters such as airfoil camber, leading edge shape and blade tip shape on single small-scale rotors. Figure of merit was measured experimentally for the different rotor configurations studied. Blades having circular arc airfoils with sharp leading edges were tapered at the tip such that negative twist and gradual camber reduction were simultaneously introduced. A large increase in the maximum figures of merit with respect to rotors with rectangular blades was observed when asymmetric linear taper on the outer 20 percent of the blades was used, reaching values of up to 0.65.