ANCILLARY AERODYNAMIC STRUCTURES FOR AN UNMANNED AERIAL VEHICLE HAVING DUCTED, COAXIAL COUNTER-ROTATING ROTORS

摘要

An unmanned aerial vehicle (UAV) (100) having a toroidal fuselage (120) and a rotor assembly (170) including counter-rotating rotors coaxially mounted with respect to the toroidal fuselage incorporates ancillary aerodynamic structures (18) having a cambered airfoil profile to provide a nose-down pitching moment to counteract the nose-up pitching moment generated by airflow over the toroidal fuselage during forward translational flight of the UAV The ancillary aerodynamic structures are symmetrically mounted in combination with the lateral sides of the toroidal fuselage so that the centers of lift are located aftwardly of the fuselage axis of the toroidal fuselage in forward translational flight modes. In a first embodiment, the ancillary aerodynamic structures (18) are fixedly mounted in combination with the toroidal fuselage (10) at a predetermined angle of incidence. In a second embodiment, the ancillary aerodynamic structures (19) are rotatably mounted in combination with the toroidal fuselage (10') to provide variable incidence ancillary aerodynamic structures for the UAV.