AERODYNAMICALLY-INDUCED WING-FLAPPING FOR THE PROPULSION OF ORNITHOPTERS

摘要

Ornithoper employing aerodynamically-induced wing-flapping as a means to reduce the input power required for its propulsion. Most existing designs of ornithopters employ direct mechanical means in one form or another to flap their wings. Such arrangements place a high demand on the pilot/engine in view of the large inertia of the virtual air mass set in motion by the flapping wings. The intent of this invention is to employ the increase in the lift force generated on the outboard wing segment, when the latter is yawed forward, to lever the whole wing upwards away from its spring-restrained initial position. The downstroke is achieved by a reverse torque which develops as the impulsive lift force on the outboard wing segment diminishes when the latter's forward sweeping motion is slowed down or halted. When a suitable speed is reached the stick (15) is pulled back which causes the outboard wing segment (3) to be flicked forward in a yawing motion generating impulsive lift. The impulsive torque forces the whole wing upwards against the pull of the restraining cable (7) and spring (8).