Abstract: Shape memory alloy-actuated propeller blades and shape memory alloy-actuated propeller assemblies are disclosed. An example propeller blade includes a propeller body, a plate coupled to the propeller body, a torque transfer member, and a shape memory alloy (SMA) actuator. The torque transfer member has a distal end attached to the plate such that the torque transfer member applies to the plate at least a portion of a torque applied to the torque transfer member at a proximal end of the torque transfer member. The SMA actuator has a distal end and a proximal end. The distal end of the SMA actuator is attached to the torque transfer member. The proximal end of the SMA actuator is coupled to the propeller body such that the distal end is mated to the propeller body. The SMA actuator is configured to apply the torque to the proximal end of the torque transfer member in response to an application of heat to the SMA actuator.

Abstract: Shape memory alloy-actuated propeller blades and shape memory alloy-actuated propeller assemblies are disclosed. An example propeller blade includes a propeller body, a plate coupled to the propeller body, a torque transfer member, and a shape memory alloy (SMA) actuator. The torque transfer member has a distal end attached to the plate such that the torque transfer member applies to the plate at least a portion of a torque applied to the torque transfer member at a proximal end of the torque transfer member. The SMA actuator has a distal end and a proximal end. The distal end of the SMA actuator is attached to the torque transfer member. The proximal end of the SMA actuator is coupled to the propeller body such that the distal end is mated to the propeller body. The SMA actuator is configured to apply the torque to the proximal end of the torque transfer member in response to an application of heat to the SMA actuator.

Abstract: In an exemplary variable area nozzle, a fixed duct section has an inlet and an outlet oriented approximately perpendicular to the inlet. A controllable nozzle member is disposed adjacent the outlet of the fixed duct section. The controllable nozzle member has an area that is adjustable to maintain a substantially constant nozzle pressure ratio. The controllable nozzle member may include first and second flap doors hinged and pivotable in opposite directions between an open position and a closed position and that also may be hinged and pivotable in a same direction so thrust from gas exiting the nozzle is vectorable. When disposed in rotor tips of an aircraft capable of rotary wing flight and fixed wing flight, the variable area nozzle may maintain a substantially constant nozzle pressure ratio near an optimized nozzle pressure ratio as the aircraft transitions from rotary wing flight to fixed wing flight.

Abstract: An aircraft includes at least one turbofan engine assembly having a shrouded core engine, a short nacelle surrounding a fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle. A mixer duct shell is positioned substantially coaxial with the engine shroud and extends forwardly into the fan duct to provide an interstitial mixer duct between the mixer duct shell and the core engine shroud. The aft portion of the mixer duct shell extends over a turbine exhaust frame, an attached mixer (if included), and a tail cone exhaust plug. The mixer duct shell can reduce noise and plume exhaust heat radiated from aircraft turbofan engines.

Abstract: In an exemplary variable area nozzle, a fixed duct section has an inlet and an outlet oriented approximately perpendicular to the inlet. A controllable nozzle member is disposed adjacent the outlet of the fixed duct section. The controllable nozzle member has an area that is adjustable to maintain a substantially constant nozzle pressure ratio. The controllable nozzle member may include first and second flap doors hinged and pivotable in opposite directions between an open position and a closed position and that also may be hinged and pivotable in a same direction so thrust from gas exiting the nozzle is vectorable. When disposed in rotor tips of an aircraft capable of rotary wing flight and fixed wing flight, the variable area nozzle may maintain a substantially constant nozzle pressure ratio near an optimized nozzle pressure ratio as the aircraft transitions from rotary wing flight to fixed wing flight.

Abstract: An aircraft includes at least one turbofan engine assembly having a shrouded core engine, a short nacelle surrounding a fan and a forward portion of the core engine, and a fan exhaust duct through the nacelle. A mixer duct shell is positioned substantially coaxial with the engine shroud and extends forwardly into the fan duct to provide an interstitial mixer duct between the mixer duct shell and the core engine shroud. The aft portion of the mixer duct shell extends over a turbine exhaust frame, an attached mixer (if included), and a tail cone exhaust plug. The mixer duct shell can reduce noise and plume exhaust heat radiated from aircraft turbofan engines.