Abstract:
A propeller system combines innovative strategies to create a new methodology to reduce propeller or rotor noise. The propeller is specifically aimed for ultra-quiet electrically powered aircraft for use in high proximity aviation, but its low-noise advantages will extend to other purposes. The propeller blade includes geometries, along with size and operational limitations that minimize rotational and vortex noise, vibration and span-wise air flow on the blade. To further reduce noise, the propeller provides greater relative thrust on the inboard portions of the blade than do conventional propellers and provides less than conventional relative thrust including negative thrust at the outermost portions of the blade. The propeller blade includes stepped changes in shape at calculated intervals that can reduce resonant blade vibrations and their resultant noise. This ultra-quiet propeller design can also be used for quieting hovercraft, drones, surveillance aircraft, indoor fans, wind tunnels and other applications.
Abstract:
A tail rotor blade for a helicopter includes a blade body defining a longitudinally extending spar cavity, a leading edge forward of the spar cavity, and a trailing edge aft of the spar cavity. Upper and lower airfoil surfaces extend from the leading edge to the trailing edge on opposite sides of the spar cavity. The upper and lower airfoil surfaces define between one another a constant airfoil segment and transition airfoil segments disposed longitudinally adjacent to the constant airfoil segment on inboard and outboard sides of the constant airfoil segment.
Abstract:
A method of controlling noise of an aircraft includes storing a plurality of predefined noise modes; receiving a selection of a selected noise mode from the plurality of predefined noise modes, the selected noise mode identifying at least one operational parameter; and controlling the aircraft in response to the at least one operational parameter.
Abstract:
Sistema y procedimiento sustentador, propulsor y estabilizador para aeronaves de despegue y aterrizaje vertical que consiste en aplicar simultáneamente y combinados como sustentadores durante el tramo inicial del ascenso y al final del descenso: a) unos fanes o turbinas eléctricas, EDF y b) al menos un rotor de palas externas y/o de alas giratorias, y/o c) el flujo de los motores dirigido hacia abajo y/o d) chorros de aire a presión inyectado sobre bordes de ataque de las aletas de control, y/o e) chorros de agua, y/o í) complementados con la sustentación aerodinámica producida durante el avance frontal de la aeronave, la estabilización se consigue con la rigidez giroscópica de los rotores y dos o más fanes sustentadores, aletas oscilantes y/o chorros de aire estabilizadores situados en dos o mas puntos periféricos en un plano normal al eje vertical de la aeronave.
Abstract:
A trim tab assembly includes first and second shape memory alloy (SMA) actuators and a trim tab substrate which provide elastic/plastic locking in response to an induced strain actuation.
Abstract:
A main rotor blade assembly includes a tip spar which defines a tip spar non-straight form, an upper blade skin which defines an upper blade skin non-straight form adjacent to the tip spar non-straight form and a lower blade skin which defines a lower blade skin non-straight form adjacent to the tip spar non-straight form.
Abstract:
The invention relates to an adjustable blade profile of the rotor blade of a rotary wing aircraft. Said blade profile consists of a blade base body and the two profile edges. At least one of said profile edges can be adjusted about an axial direction along the longitudinal axis of the blade. The aim of the invention is to provide a helicopter rotor blade with an aerodynamic profile that can be adjusted in such a manner that the aerodynamics thereof can be better adapted to the flight conditions and the compensation of the aerodynamic lift between forward and rearward direction of the blade and which at the same time requires less expenditure. To this end, the invention provides the characterizing features of claim 1. The inventive design facilitates a self-adjusting profile change of the rotating blade.
Abstract:
A high-lift main rotor system (1) is provided for a full-size or model helicopter (15). Main rotor system (1) includes rotor blades (100) and subrotor blades (84) for producing aerodynamic lift. The subrotor blades (84) act to augment control and stability of main rotor (1). Main rotor blades (100) are configured to include airfoiled cross sections (103-107) of varying shape and are mounted to a rotor hub (77) to fold within limits about a horizontal flapping axis (10). A linkage including swashplate (140) is provided for transmitting pilot control commands to the rotating rotor blades (100).