3results about How to "Reduce flight resistance" patented technology

This invention discloses a landing buffer device for unmanned aerial vehicles (UAVs), relating to the field of aviation equipment technology. By integrating the roller body and the sliding plate as two grounding structures onto the landing gear, the device can quickly switch operating modes according to ground conditions through the linkage of the piston cylinder and piston rod. On flat ground, the roller is used first to reduce gliding resistance, while on muddy or slippery ground, the sliding plate is used for grounding, effectively preventing roller jamming and enhancing all-terrain adaptability and landing safety. Simultaneously, the mechanical buffer composed of a second and third spring, combined with the hydraulic damping buffer composed of buffer components, forms a highly efficient double-layer energy-absorbing buffer structure, which to a certain extent alleviates the damage to the aircraft and equipment caused by landing impact, thus improving the landing safety of the UAV.

The utility model discloses a kind of unmanned aerial vehicle for realizing vertical take-off and attitude control using small turbojet engine, small turbojet engine is installed at wing tip of wing, small turbojet engine is installed at the back of fuselage (or in front of fuselage) two sides;Small turbojet engine is made to produce upward thrust by vertical rotation 90 ° using turbine worm drive mechanism or motor with self-locking holding torque, and unmanned aerial vehicle vertical take-off is realized;Unmanned aerial vehicle has aileron installed at the trailing edge of left and right wing tips, and the differential deflection of aileron makes unmanned aerial vehicle tilt rotation around longitudinal axis, and the direction of thrust of small turbojet engine is deflected using turbine worm drive mechanism, to realize the flight state stabilization and flight attitude control of unmanned aerial vehicle, so that unmanned aerial vehicle has good maneuverability;Horizontal stabilizer and elevator are omitted, vertical stabilizer and rudder are omitted, so as to reduce flight resistance, which is conducive to improving the flight speed and effective load of unmanned aerial vehicle.

The application discloses a non-rotation body warhead drag reduction method based on a von Karman curve, and comprises the following steps: S1, determining a non-rotation body warhead, a warhead section and a warhead vertex according to a flight speed, wherein a projection point of the warhead vertex at the warhead section falls on an intersection of the warhead section and a warhead symmetry plane; S2, selecting a key point located at an edge of the warhead section; S3, generating a von Karman curve on the warhead symmetry plane as a warhead contour generatrix, obtaining parameters required by a von Karman curve of a key point of a warhead connection section, and generating a von Karman curve group connecting the warhead vertex and the key point of the section; and S4, creating a plurality of planes perpendicular to the warhead symmetry plane, truncating the von Karman curve group, generating a multi-section curved surface, and closing the multi-section curved surfaces to form a solid warhead contour. The non-rotation body warhead drag reduction method based on the von Karman curve has the beneficial effects of reducing flight drag and improving flight stability.