The novel aerodynamics of insect flight: Applications to micro-air vehicles

The wing motion in free flight has been described for insects ranging from 1 to 100 mm in wingspan, To support the body weight, the wings typically pr oduce 2-3 times more lift than can be accounted for by conventional aerodyn amics, Some insects use the fling mechanism: the wings are clapped together and then flung open before the start of the downstroke, creating a lift-en hancing vortex around each wing. Most insects, however, rely on a leading-e dge vortex (LEV) created by dynamic stall during flapping; a strong spanwis e flow is also generated by the pressure gradients on the flapping wing, ca using the LEV to spiral out to the wingtip. Technical applications of the f ling are limited by the mechanical damage that accompanies repeated clappin g of the wings, but the spiral LEV can be used to augment the lift producti on of propellers, rotors and micro-air vehicles (MAVs). Design characterist ics of insect-based dying machines are presented, along with estimates of t he mass supported, the mechanical power requirement and maximum flight spee ds over a wide range of sizes and frequencies. To support a given mass, lar ger machines need less power, but smaller ones operating at higher frequenc ies mill reach faster speeds.