Abstract: A rotor assembly has: blades having airfoils and roots protruding from platform segments; a rotor disc having a peripheral face defining recesses, and slots, a recess located between two adjacent ones of the slots and bounded by a step; feather seals located radially between the peripheral face and the platform segments, a feather seal having a core extending from a trailing end to a leading end and overlapping a gap defined between two platform segments and tabs protruding from the core, the tabs including: trailing tabs positioned axially outside the recess; and leading tabs, a leading tab extending from a root to a tip and having one or more of: the tip axially positioned outside of the recess; and a fillet at an intersection between the tip and an edge of the leading tab, the edge extending between the tip and the core, and facing the step.

Abstract: A vibration damping system includes a vibration damping element for a turbine nozzle or blade. A body opening extends through the turbine nozzle or blade between the tip end and the base end thereof, e.g., through the airfoil among potentially other parts of the nozzle or blade. A vibration damping element includes a plurality of stacked plate members within the body opening. Each plate member is in surface contact with at least one adjacent plate member to cause friction that dampens vibration of the nozzle or blade. The body opening has an inner dimension, and each plate member has an outer dimension sized to frictionally engage the inner dimension of the body opening to damp vibration. Plate members may each include a central opening therein, and a fixed elongated body or cable may extend through the central openings. The damping element may alternatively include a helical metal ribbon spring.

Abstract: Morphable rotor blades for a turbine engine systems include a root portion and an airfoil portion having a morphable portion including a morphable material that changes shape in response to a stimulus.

Abstract: The present invention relates to a partly assembled structure in the form of a structure comprising a wind turbine tower, a nacelle arranged thereon and a vibration damper attached to the nacelle for damping vibrations of the combined wind turbine tower and nacelle within a selected frequency range, wherein the vibration damper is operatively connected to a main shaft of the nacelle, or wherein the vibration damper is attached to the nacelle via a nacelle transportation interface. The present invention further relates to a method of constructing a wind turbine and a method for damping Vortex induced vibrations of the combined wind turbine tower and nacelle within the selected frequency range.

Abstract: A damper element for a vibration dampening system may be used in a body opening in a rotating blade in a turbine. The damper element includes a base member having an axially fixed position within the body opening, and a spring-suspended bearing member having a spring fixedly coupled to the base member at a first end of the spring and a bearing member coupled to a second end of the spring. With the spring in an elastically extended state under influence of a centrifugal force caused by rotation of the rotating blade at higher than a predefined rotational speed, the bearing member frictionally engages a bearing surface to dampen vibration. The spring-suspended bearing member provides a friction-based vibration dampening interface that experiences a reduced impact of the centrifugal forces of the rotating blade by providing a counteracting force reduction using the spring.

Abstract: The present invention relates to a fan rotor with variable pitch blades, comprising a rotor disc, equipped at its periphery with a plurality of rotary fasteners (16), each fastener (16) comprising a cell (17) for receiving the root (150) of a blade (15).

Abstract: A rotor blade system. The rotor blade system includes a rotor and a plurality of blades coupled to the rotor. The plurality of blades are arranged in an airfoil distribution pattern. The airfoil distribution pattern includes one or more baseline blades and one or more intentionally mistuned blades including an intentional mistuning feature.

Abstract: A gas turbine engine comprising a set of circumferentially adjacent airfoils, the airfoils having an outer wall defining a pressure side and a suction side extending between a leading edge and a trailing edge to define a stream-wise direction, and between a root and a tip to define a span-wise direction, and a set of dimples provide on the outer wall of at least one of the airfoils, the set of dimples spaced in at least one of the stream-wise or span-wise directions.

Abstract: A rotary machine includes a rotary shaft that rotates around an axis, a plurality of rotor blades arranged on an outer peripheral side of the rotary shaft in a circumferential direction in which the rotor blade has a blade root, a platform, and a blade main body; and each damper member provided radially inward of the platform, in which the platform includes a first end surface that faces one side in the circumferential direction, and a second end surface that faces the other side in the circumferential direction so that the second end surface faces the first end surface of the adjacent other platform, and the damper member includes a first damper provided on the first end surface and having a first abutting surface, a second damper that has a second abutting surface slidably abutting the first abutting surface of the first damper and is abuttable on the second end surface, and an elastic member that bonds together the first damper and the second damper.

Abstract: An arrangement reduces oscillation (vibration) of an oscillatory structure. The arrangement has a structure having at least one mode in at least one direction; and an oscillation-reducing device (vibration-reducing device). The oscillation-reducing devices has a housing formed by or provided on the structure, a cavity, and a body configured for making impact contacts with the housing and disposed in the cavity in such a manner that the body is configured to make impact contacts with the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least on direction.

Abstract: An arrangement reduces oscillation of an oscillatory structure. The arrangement has: a structure having at least one mode in at least one direction; and an oscillation-reducing device. The oscillation-reducing device includes a housing on the structure; a cavity; and a body. The body is configured to make impact contact with a first surface portion and a second surface portion of an inner wall of the housing and disposed is in the cavity such that the body can make impact contact with the first surface portion and the second surface portion of the inner wall of the housing at least temporarily for as long as the structure is excited in the at least one mode in the at least one direction. The first surface portion or the second surface portion of the inner wall of the housing has a curved profile.

Abstract: A composite platform for a fan of an aircraft turbine engine. The platform includes an elongate wall and is configured to extend between two fan blades. The wall includes an aerodynamic outer surface and an inner surface, on which a fastening tab is located, wherein the fastening tab is configured to be attached to a fan disc. The fastening tab is integrally formed with a metal reinforcement which has a plate having an elongate shape and which extends over more than 50% of the longitudinal extent of the wall, the wall being produced by overmolding a resin on the plate so as to be integrated into the wall.

Abstract: An integrally bladed rotor for a turbomachine, in particular a compressor or turbine stage of a gas turbine, to which at least one separately formed impulse element housing (40; 40?) is fastened by at least one fastening element (30; 30?) which engages for this purpose into an opening (41) of the impulse element housing and into an opening (11) of the rotor, the impulse element housing having at least one cavity (44) in which at least one impulse element (5) is accommodated with play.

Abstract: An aircraft turbomachine rotor has a rotor disc extending transversely with respect to a longitudinal axis X, a plurality of blades, and a damping device. The damping device having: a support ring arranged transversely with respect to the longitudinal axis X and mounted on the outer periphery of the rotor disc, and has a plurality of damping members that are attached to the support ring and project upstream from the support ring, each damping member being configured to extend at least under a platform of a blade so as to exert a radially outward force to dampen the radial movement of the blade when the turbomachine is in operation.

Abstract: A method of disassembling a rotor module of a gas turbine engine. The gas turbine engine having a rotor output shaft. The rotor module having a centre-bolt, a sleeve, at least one rotor stage, at least one stator stage, a casing and an axis. The method having the steps: attaching a fixture to the at least one rotor stage, attaching the fixture to the casing, detaching the centre-bolt from the at least one rotor stage, detaching the sleeve from the output shaft, attaching the fixture to the sleeve, and removing the rotor module and fixture from the rotor output shaft. There is also presented a method of assembling the rotor module to the gas turbine engine and the apparatus used for disassembly and assembly.

Abstract: Rotor blades, vibrational dampening elements, and methods are provided. A rotor blade includes a platform, a shank extending radially inward from the platform, and an airfoil extending radially outward from the platform. One or more fluid chambers are defined within the rotor blade. Glass is disposed within each fluid chamber of the one or more fluid chambers. A mass is disposed within each fluid chamber of the one or more fluid chambers. The mass is movable within the glass relative to the airfoil.

Abstract: An airfoil for use in a gas turbine engine is formed to define a cavity formed in the airfoil. The airfoil further includes at least one obstructing member arranged within the cavity and a shear-thickening fluid disposed in the cavity. A viscosity of the shear-thickening fluid increases in response to the airfoil experiencing an aeromechanic response or vibrations such that the obstruction of the movement of the thicker fluid by the obstructing member dampens the vibrations of the airfoil and reduces negative effects of a dynamic response of the airfoil.

Abstract: Water droplets that are moved on blade surfaces of a rotor blade are effectively guided toward the blade trailing edge while influence on the strength of the rotor blade is suppressed. A steam turbine rotor blade having a tie-boss for joining to adjacent blades at an intermediate position in the blade length direction is provided. The steam turbine rotor blade includes an airfoil part in which a blade surface is partly hollow as viewed in a section obtained by cutting by an orthogonal plane to a rotation center line of a turbine and a recessed blade surface that is this hollow partial blade surface passes through the blade root side of the tie-boss at least in a region on the pressure side and extends in a strip shape in the blade chord length direction.

Abstract: A vibration attenuator is configured for use on an aircraft rotor rotatable about a mast axis and has upper and lower weight assemblies, each comprising a weight with a center of gravity being a radial distance from the mast axis. The weight assemblies are configured for rotation together relative to the rotor at a selected angular rate about the mast axis, the weights being located on opposing sides of the mast axis. A first motor is configured for selective translation of one of the weight assemblies relative to the other weight assembly along the mast axis between a minimum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in the same plane, and a maximum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in different planes for producing a whirling moment about the mast axis.

Abstract: A yaw control system for a helicopter having an airframe that includes a tailboom includes one or more tail rotors rotatably coupled to the tailboom and a flight control computer implementing an airframe protection module. The airframe protection module includes an airframe protection monitoring module configured to monitor one or more flight parameters of the helicopter and an airframe protection command module configured to modify one or more operating parameters of the one or more tail rotors based on the one or more flight parameters of the helicopter, thereby protecting the airframe of the helicopter.

Abstract: A damper position-limiting device is provided, which is mounted in a tower to limit the swing amplitude of a damper installed in the tower. The damper position-limiting device includes at least one web and a position-limiting ring. The web is provided with a mounting hole and at least one stress relief hole. A first side wall of the web has a first specified length along a circumferential direction of the inner wall of the tower, and is connected to the inner wall of the tower. The position-limiting ring is positioned within the mounting hole and connected to the mounting hole and is configured to accommodate an impacting plate of the damper.

Abstract: Blades including integrated damping structures are disclosed herein. An airfoil to be disposed within a flow path of a gas turbine engine, the gas turbine engine defining an axial axis, a radial axis and a circumferential axis comprising an airfoil body including a first face, a second face and a recessed portion formed in the second face, and an airfoil cap having a first surface, the airfoil cap disposed within the recessed portion, the first surface substantially flush with the second face.

Abstract: A vibration damping system for a turbine nozzle or blade includes a body opening extending through a body of the turbine nozzle or blade between a tip end and a base end thereof. Elongated vibration damping element is disposed in the body opening and includes an elongated body having a first, free end and a second end fixed relative to one of the base end and the tip end. At least one wire mesh member surrounds the elongated body. The wire mesh member(s) frictionally engage with an inner surface of the body opening to damp vibration. A related method is also disclosed.

Abstract: A bottom-mounted whole house fan assembly includes an intake plenum mounted over an opening in a ceiling of a building. The intake plenum is supported on the ceiling in the attic of the building. One end of a flexible duct is connected to the intake plenum and the other end of the duct is connected to a fan so that the fan draws air in the building through the intake plenum and duct and exhausts the air in the attic from whence the air is vented to atmosphere. The fan is supported by at least one vertical strut that is connected to the ceiling at the lower end of the strut and to a housing of the fan at the upper end of the strut. A sound dampener is interposed between the strut and the fan housing and/or the ceiling beam to which the strut is attached.

Abstract: A vibration damping system for a turbine nozzle or blade includes a vibration damping element including a plurality of contacting members including a plurality of damper pins. Each damper pin includes a body. A wire mesh member surrounds the body of at least one of the plurality of damper pins. The wire mesh member has a first outer dimension sized for frictionally engaging within a body opening in the turbine nozzle or blade to damp vibration. Spacer members devoid of a wire mesh member may also be used. The damper pins can have different sizes to accommodate contiguous body openings of different sizes in the nozzle or blade. The body opening can be angled relative to a radial extent of the nozzle or blade.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed. An inner shroud damper for a gas turbine engine includes: at least one carrier including a joint to couple to an inner shroud, the at least one carrier having a first side and a second side, and at least one mass damper coupled to the at least one carrier.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a propulsor section including a propulsor, a turbine section including a first turbine and a second turbine, a compressor section driven by the turbine section, the compressor section including a first compressor and a second compressor, and a geared architecture driven by the first turbine. The propulsor is driven by the first turbine via the geared architecture. At least one stage of the turbine section includes an array of rotatable blades and an array of vanes. A ratio of the number of vanes to the number blades is greater than or equal to 1.55. A mechanical tip rotational Mach number of the blades is configured to be greater than or equal to 0.5 at an approach speed.

Abstract: An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, and pitch angles between adjacent blades are all different. In terms of an arbitrary pitch angle ?, when a pitch angle ?1 adjacent to the pitch angle ?, and a pitch angle ?2 adjacent to the pitch angle ?, different from the pitch angle ?1, satisfy a relation, ?1<?2, a pitch angle ?1 different from the pitch angle ? adjacent to the pitch angle ?1 and a pitch angle ?2 adjacent to the pitch angle ?2, different from the pitch angle ?, satisfy a relation, ?2<?1.

Abstract: A rotor for a hover-capable aircraft is described, comprising: a hub rotatable about an axis and, in turn, comprising a plurality of blades; a mast connectable to a drive member of the aircraft and operatively connected to the hub to drive the hub in rotation about the axis; and damping means for damping vibrations transmitted to the mast, which comprise a mass designed to oscillate in a plane transversal to the axis so as to contain flexural vibrations of the mast generated by rotation of the blades; the damping means also comprise elastic means having a desired stiffness along the axis and operatively connected to the mass to contain vibration of the mast along the axis.

Abstract: A turbine blade includes an internal vibration damping system having a plurality of unit cells. Each unit cell includes: an impacting structure; and a cavity encapsulating the impacting structure. The cavity, which includes a first hemisphere and a second hemisphere, is disposed within a substrate, which forms an outer casing of the cavity. At least one fluid is disposed in each of the first and second hemispheres between the impacting structure and the outer casing.

Abstract: A turbine wheel is provided with a groove having a bottom surface and a pair of side wall surfaces. The turbine wheel includes: a balance weight that is arranged in the groove, is insertable from any circumferential position of the opening of the groove, and has a through-hole opened toward one of the pair of side wall surfaces; and a retaining member that contacts the one of the pair of side wall surfaces in a state of being inserted in the through-hole of the balance weight, to thereby cause the balance weight to abut against the other one of the pair of side wall surfaces and be retained in the groove. The groove has engagement recesses provided at intervals in a circumferential direction at the bottom surface or an engagement protrusion fitted to one of fitting recesses provided at intervals in the circumferential direction at the bottom surface and protruding from the bottom surface.

Abstract: A rotor blade attached to a rotor shaft rotatable around an axis includes: a blade body extending in a radial direction with respect to the axis and having a blade-shaped cross section orthogonal to the radial direction; a shroud provided at an end of the blade body on a radial outer side, and a seal fin protruding from the shroud toward an outer circumferential side, and the seal fin includes: a seal fin body extending in a plate shape in a circumferential direction; and a reinforcing portion provided on at least one plate surface of the seal fin body to increase a thickness of the seal fin, the reinforcing portion gradually increasing in dimension in the radial direction toward the center in the circumferential direction.

Abstract: The invention relates to a torque transmitting device comprising a torque input element (17a, 17b) and a torque output element (8) able to pivot about a shaft (X) with respect to one another, at least one elastic leaf (22), rotationally coupled to the torque output element (8) or to the torque input element (17a, 17b) respectively, the elastic leaf (22) being able to be elastically and radially supported by a supporting member (18) carried by the torque input element (17a, 17b) or the torque output element (8) respectively, the elastic leaf (22) being able to bend upon rotation of the torque input element (17a, 17b) with respect to the torque output element (8).

Abstract: A blade (1) for a turbomachine, including a turbine blade (1.1) which has a channel (1.5), an impact chamber (2) having a constricted cross section being situated in the channel for the purpose of accommodating a single impulse body (3) is provided.

Abstract: An online real time steam or gas turbine engine rotor balancing system is incorporated in a rotor balance plane. A selectively displaceable balancing weight is coupled to the rotor and is selectively displaced by a motor that is coupled to the balancing weight. The motor selectively displaces the balancing weight along a displacement path that is in the balance plane. A turbine engine rotor vibration monitoring system monitors rotor vibration in real-time. A control system is coupled to rotor vibration monitoring system and the motor, for determining in real time a desired balance weight displacement position to counteract the monitored rotor vibration. The controller selectively causes the motor to displace the balancing weight to the desired displacement position. The motor power source is an inductive power source or a permanent magnet generator.

Abstract: A damper body extends between an axial first end, an opposing axial second end, a first lateral side, and an opposing second lateral side. A first pair of lugs are disposed at the first axial end and a second pair of lugs are disposed at the second axial end. In the first lug pair, a lug has an axially outermost foot which extends laterally beyond a lateral wall. The second lug pair has a lug with an axial outermost point with a foot extending laterally beyond a lateral wall. The foot on the first axial end and the foot on the second axial end are on opposed lateral sides.

Abstract: The present application provides a compressive stress system for a gas turbine engine. The compressive stress system may include a first bucket attached to a rotor, a second bucket attached to the rotor, the first and the second buckets defining a shank pocket therebetween, and a compressive stress spring positioned within the shank pocket.

Abstract: A turbine wheel for a turbine engine, comprising a disk carrying blades, each having a platform carrying an airfoil and connected by a tang to a root, and sealing and damping sheets housed in the inter-tang spaces, the platforms including projections on their radially internal faces against which the sheets bear radially in operation, in order to define radial clearance and create at least one space between the sheets and the platforms, and the sheets including holes for feeding air to the or each space.

Abstract: An aircraft system/method for propeller balancing.

Abstract: An aircraft system and method with a first counterweight rotating balancing rotor mass concentration, and a second counterweight rotating balancing rotor mass concentration to balance a first aircraft propeller. The system includes an inboard electromagnetic coil driver with a first inboard electromagnetic coil, and a second inboard electromagnetic coil, the inboard electromagnetic coil driver and the first counterweight balancing rotor and the second counterweight balancing rotor centered around the aircraft propeller shaft rotating machine member. The system/method utilizes a first control system controller to control the coils and position the mass concentrations to balance the first aircraft propeller. The system/method includes a third counterweight rotating balancing rotor mass concentration, and a fourth counterweight rotating balancing rotor mass concentration to balance a second aircraft propeller which positioned and controlled by a second control system controller.

Abstract: A device for damping of vibratory energy in the blades of rotor assemblies during operation where the blades have a shroud attached thereto with at least one sealing rail extending radially outward from the shroud to an outer diameter surface. A damper element is attached to the turbine blade sealing rail extending radially inward from the rail outer diameter surface along rail sides to maintain the damper element out of the flow of gas and positioned at a radial location on the blade for damping.

Abstract: A gas turbine engine blade comprises a dovetail, a shank extending from the dovetail, an airfoil, and a platform between the shank and the airfoil. The platform comprises a side wall extending between an upstream side and a downstream side of the platform. A first pin channel extends from the upstream side of the sidewall and a second pin channel, co-axial with the first pin channel, extends from the downstream side of the sidewall. The first channel includes a radial notch at the upstream longitudinal end of the first pin channel.

Abstract: A main rotor arrangement for an UAV-helicopter. A rotor mast defines a vertical axis of rotation. A hub is for attachment of rotor blades. The hub is mounted to the rotor mast in a tiltable way so as to reduce loads acting on the rotor blades during operation of the UAV-helicopter. A damping assembly is configured to damp the tilting of the hub.

Abstract: A fan wheel (1) is designed as a radial or diagonal fan, comprising a top plate (2) with an inlet port (4), a base plate (6) and a plurality of fan blades (8) distributed around the inlet port (4) and around an axis of rotation (Z). Blade ducts extend (10) respectively between the adjacent fan blades (8). The blade ducts lead radially or diagonally outward from the area of the inlet port (4) and form blow-out ports in the outer region. The blade ducts (10) are designed, with respect to their effective flow cross-section, as large enough that during operation, a turbulent flow with a Reynolds number markedly greater than 2300 is achieved. The top plate (2) or the base plate (6) or both feature a rotationally asymmetrical geometry with a continuous profile, at least in angular sections encompassing the fan blades (8).

Abstract: By providing a tube of deformable material which can be located within a hollow cavity of a blade it is possible to provide an element which through friction engagement can absorb vibration energy and therefore damp vibration in a hollow blade. The tube incorporates a number of cuts and/or grooves in an appropriate pattern in order to define a deformation profile once the tube is expanded in location. The tube is secured in position internally upon an expandable element which is typically an inflatable device. Once in position the tube is retained in its expanded deformable profile and the engagement between the tube and the hollow cavity wall surface results in energy absorption through vibration episodes. It is possible to provide a tube formed from a shape memory alloy which will expand in location to engage the hollow cavity wall surfaces for energy absorption during vibration episodes.

Abstract: An aerofoil has first and second panels spaced apart from each other to provide a cavity, the cavity containing a damping material, the first panel has at least one protrusion extending therefrom within the cavity towards the second panel, the protrusion having a proximal end and a distal end, wherein the proximal end is secured to the first panel and the distal end is slidably mounted to the second panel.

Abstract: An airfoil includes an airfoil body that defines a longitudinal axis. The airfoil body includes a leading edge and a trailing edge and a first sidewall and a second sidewall that is faced apart from the first sidewall. The first sidewall and the second sidewall join the leading edge and the trailing edge and at least partially define a cavity in the airfoil body. A damper member is enclosed in the cavity. The damper member includes a first end and a second end. The first end is connected in a first joint to the first sidewall at a first longitudinal location and the second end is connected in a second joint to the second sidewall at a second, different longitudinal location.

Abstract: A vibration-damping shim configured to be interposed between a platform of a fan blade and a fan disk, including a radially external surface fitted with plates in contact with the fan blade platform, and a radially internal surface formed by an upstream surface, configured to be facing the disk, and a downstream surface separated from the upstream surface by a break in alignment. The upstream surface includes a zone protruding radially towards the interior, initiated at some distance from its upstream end.

Abstract: A bucket for a turbomachine rotor wheel includes an airfoil portion, a shank portion and a dovetail mounting portion, the shank portion including opposite sides, one of the sides formed with a substantially axially-oriented groove extending between forward and aft ends of the shank portion. The other one of the opposite sides is formed with at least one substantially radially-oriented groove. The substantially axially-oriented groove is adapted to receive an elongated damper pin, and the at least one substantially radially-oriented groove is adapted to receive an elongated radial seal pin.

Abstract: A device (10) for reducing the vibration of a rotorcraft main rotor (1) provided with a hub (2) and a plurality of blades, said device having a support (20) together with at least one weight element (30). Said weight element (30) is fastened to said support (20) by connection means (40), and said weight element (30) is connected to said connection means (40) by guide means (50) for guiding said weight element (30) in movement in circular translation in a filter plane (P1) that is movable perpendicularly to an elevation axis (AX) of said device (10), said connection means (40) including resilient return means (41) serving to allow said filter plane (P1) to move in elevation while keeping the filter plane (P1) perpendicular to said elevation axis (AX) under the effect of said vibration.