A propeller system for an aircraft includes an assembly for modifying a sound field of the propeller system. The propeller system includes a rotor supported for rotation about a rotor axis. The rotor has a central hub and a plurality of blades each extending outwardly from the hub to a tip. The rotor and blades are operable to propel an aircraft to travel in a direction. The rotor blades define a rotor plane perpendicular to the rotor axis. The blade tips define a circumferential rotational path as the blades are rotated by the rotor. The propeller system includes an acoustic resonator or multiple resonators having openings disposed within a distance to the propeller blade tip that is small compared to the wavelength of the propeller's fundamental blade tone and proximate to the rotor plane. The resonators are excited by tip flow of the blade as it passes the opening. The acoustic resonators are configured and positioned so as to direct acoustic energy to modify the sound field of the propeller system at blade pass or higher harmonic frequency tones in a desired direction relative to the aircraft.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A hub-tip ratio of the outer fan is from 1.6 to 2.2 times a hub-tip ratio of the inner fan.

A cross flow fan to be incorporated into an aircraft comprises a cross flow fan rotor to be positioned in an aircraft, a drive arrangement for the cross flow fan rotor, and a plurality of vanes positioned downstream of the cross flow fan rotor. An aircraft is also disclosed.

A propeller having a means for creating fluid flow in a non-axial direction and redirecting it in an axial direction.

A propeller having a means for creating fluid flow in a non-axial direction and redirecting it in an axial direction.

A blade is provided for the cycloidal marine propellers or cycloidal aerial rotors. Said blade is provided with the capabilities, in response to the control system commands to dynamically and in real time; flex itself along its chord in any required way, vary its relative pivot point position, change its planform by extending or retracting a trailing edge extension, differentially if needed on the right and left, turn the flap along the trailing edge in either direction or allow it to be turned by the flows. Said blade is also optionally provided with one or more elastic trailing edges whose stiffness is dynamically, and possibly differentially along the blade span, variable by the control system. For the reversal of the leading and trailing edges for operation in reverse airflow and other conditions the blades are provided with edges that can be made rigid when functioning as the leading edge and flexible if needed when functioning as the trailing edge. Also the blades are provided with the capability of varying their cross-sectional profile thickness and reshaping it. Finally the blades are given on command flow permeability along much of their surface. These capabilities will enable each control system controlled blade to continually optimally adjust to and make the best use of its immediate operating environment as it travels along its trajectory within each revolution.

An integrated wireless data system and method for avionic performance indication for measuring, monitoring and displaying in-use, real-world engine-out characteristics on a propeller driven aircraft for the purposes of health monitoring, performance optimization, and regulatory compliance is provided. Engine-out characteristics may be measured either at the propeller extension hub mounted between the engine and propeller, on the crankshaft flange, or on the propeller itself, and include, but are not limited to, the engine output torque, thrust, vibration, bending loads and temperature. Data may be transmitted wirelessly to a base unit located inside the cockpit and user selected parameters are updated on a display in real-time. The system may also store all collected data, for later download and analysis. The system may also have a software interface that can be used to download, view and analyze all recorded data, as well as to configure the system settings and alerts.

A shutdown controller for a wind turbine comprises, to improve the estimation of a state of the wind turbine, at least two sensors being adapted to provide sensor data significant for different mechanical states in the wind turbine. The controller can provide an estimated state of the wind turbine based on the sensor data from the at least two sensors and compare the state of the wind turbine with a predefined detection limit to provide a shutdown signal if the estimated state is outside the detection limit.

According to one embodiment, a method for determining a position of a rotor blade includes receiving a plurality of measurements from a plurality of magneto-resistive sensors and determining a position of the at least one magnet based on the received plurality of measurements. In this example, one of the plurality of magneto-resistive sensors and the at least one magnet moves with a rotor blade.

An aircraft includes a fuselage having a front, a center, and a rear section. A first mounting member is coupled to the front section. A second mounting member is coupled to the rear section. A first and a second wing are coupled to the center section. A plurality of power generator systems are included and coupled to the first or second mounting member. Each power generator system includes a power source, a first and a second propeller. The power source is configured to drive the first and second propeller. The first and second propeller have an axis of rotation, and are pivotable between a first and a second position. An amphibious landing gear system is coupled to an underside of the fuselage and has a flap and a bladder. The bladder is located under the flap, configured to inflate and deflate, and sized to provide buoyancy for the aircraft.