Methods, apparatus, systems and articles of manufacture corresponding to a fan blade with intrinsic damping characteristics are disclosed. An example fan blade comprises an exterior body including a first side and a second side; a first hairpin structure in contact with (a) the first side of the exterior body and (b) the second side of the exterior body; and a second hairpin structure in contact with (a) the first side and (b) the second side, wherein the first hairpin structure and the second hairpin structure are made from different materials.

Methods, apparatus, systems and articles of manufacture corresponding to a fan blade with intrinsic damping characteristics are disclosed. An example fan blade comprises an exterior body including a first side and a second side; a first hairpin structure in contact with (a) the first side of the exterior body and (b) the second side of the exterior body; and a second hairpin structure in contact with (a) the first side and (b) the second side, wherein the first hairpin structure and the second hairpin structure are made from different materials.

Platform for an aircraft turbo machine fan rotor, the platform being configured to be secured to a fan disc between two adjacent fan blades. The platform further including a longitudinal wall defining an aerodynamic external face. The wall includes a honeycomb structure interposed between two skins which are respectively an internal skin and an external skin, with the external skin defining the aerodynamic external face.

An engine assembly defining an axial direction (A) and including a gearbox, an engine core including at least one rotor, and a flexible coupling shaft having a first end and a second end along the axial direction (A). The first end of the flexible coupling shaft is connected to the engine core and the second end of the flexible coupling shaft is connected to the gearbox. A damper system is positioned at the second end of the flexible coupling shaft. The damper system is configured to reduce vibrations to the flexible coupling shaft during operation of the engine assembly.

A system and method for reducing the vibration response of a rotating system are provided. In one aspect, an optimized balance shot or solution that indicates one or more physical locations at which one or more balancing weights are to be added or removed from the rotating system is generated. The balance shot is generated based on a transfer function that is customized specifically for the rotating system. The transfer function is generated by applying one or more machine-learned models to parameter values for parameters that are associated with the rotating system. The machine-learned models can generate main effects plots, and from the plots, an effective set of parameter values can be determined. The transfer function can be generated using the effective set of parameter values so that the transfer function used to generate the balance shot is optimized specifically for the rotating system undergoing the balancing process.

A turbofan engine has a fan drivingly engaged by a shaft for rotation about a rotation axis and having: fan blades circumferentially distributed about the rotation axis and drivingly engaged by the shaft; an ice-accruing feature located on a surface of the fan exposed to an air flow flowing between the fan blades, the ice-accruing feature having a shape providing a non-axisymmetric ice accumulation on the fan to create a rotational imbalance; a balancing feature secured to the fan or to the shaft to counteract the ice-accruing feature such that the fan is rotationally balanced when the fan is free of ice, the balancing feature being located such as to be outside the air flow; an aircraft controller; and a sensor operatively connected to the fan and operable to send a signal to the aircraft controller, the signal indicative of the rotational imbalance caused by the ice-accruing feature.

A method of forming a balanced rotor blade assembly includes measuring a weight of a plurality of sub-components of the rotor blade assembly excluding a core. A configuration of a core of the rotor blade assembly is determined. In combination, the core and the plurality of sub-components achieve a target weight distribution and moment. The core is then fabricated and assembled with the plurality of sub-components to form a rotor blade sub-assembly.

A gas turbine engine including a first rotor assembly comprising a first drive shaft extended along a longitudinal direction; a housing coupled to the first rotor assembly to provide rotation of the first rotor assembly around an axial centerline; a first accessory assembly, wherein the first accessory assembly sends and/or extracts energy to and from the first rotor assembly; and a first clutch assembly disposed between the first rotor assembly and the first accessory assembly. The first clutch assembly engages and disengages the first rotor assembly to and from the first accessory assembly.

A gas turbine engine including a first rotor assembly comprising a first drive shaft extended along a longitudinal direction; a housing coupled to the first rotor assembly to provide rotation of the first rotor assembly around an axial centerline; a first accessory assembly, wherein the first accessory assembly sends and/or extracts energy to and from the first rotor assembly; and a first clutch assembly disposed between the first rotor assembly and the first accessory assembly. The first clutch assembly engages and disengages the first rotor assembly to and from the first accessory assembly.

A blade for a turbomachine includes a blade root portion for securing the blade to a rotatable annular outer drum rotor. The blade root portion includes one or more radial retention features for radially retaining each of the blade root portions within the rotatable annular outer drum rotor. Further, at least one of the radial retention feature(s) includes at least one sealing member integrated therewith.