Abstract: A diffuser-nozzle assembly for mounting at an outlet from a compressor in a turbomachine, the assembly including a nozzle including two substantially cylindrical walls, a radially inner wall and a radially outer wall that are connected together by radial vanes. The walls of the nozzle are extended downstream beyond the radial vanes and the radial spacing therebetween varies downstream from the vanes to be at a minimum substantially in register with the vanes and at a maximum between the vanes.

Abstract: A link part for a turbine engine which mounted between a fan cone and a fan disk supporting fan blades is provided. The link part includes an annular wall pierced by a plurality of orifices, each orifice for receiving a fastener member and terminated by a substantially perpendicular rim having an outer surface that provides an aerodynamic extension of the fan between an outer surface of the fan cone and an outer surface of a fan blade platform. The annular wall is made of a first material that is composite and is provided on an inner surface of the rim with a ring made of a second material that is different from the first and that is suitable for radially retaining the fan blade platform.

Abstract: A blade made of composite material including an airfoil formed of filaments or fibers, optionally woven, impregnated with a heat-curable resin, with an intrados wall and an extrados wall between the leading edge and the trailing edge; and a device for damping the vibrations incorporated in one or other of the intrados and extrados walls is disclosed. The damping device is formed of at least one layer made of viscoelastic material and a layer made of rigid material, these layers being superposed. The layer made of rigid material includes a first zone and a second zone. The layer made of viscoelastic material is interposed between the airfoil and the first zone of the rigid layer, and the second zone of the rigid layer is attached to the wall of the airfoil without interposition of viscoelastic material.

Abstract: A method for reducing the vibration levels capable of occurring, in a turbine engine including at least one propeller and one coupling structure of the turbine engine, because of the turbulence of aerodynamic origin generated by the coupling structure on the propeller. The method includes: defining an initial configuration of the aerodynamic profiles, calculating the synchronous forced response on the propeller as a function of the force of harmonic excitation generated by the coupling structure expressed in the form of a linear function of the generalized aerodynamic force for the mode in question, and determining a tangential geometric offset value ? of the individual aerodynamic profiles for stacked sections of one of the propeller or of the coupling structure in order to reduce the term corresponding to the generalized aerodynamic force. The combination of the sections with the tangential offsets therefore defines a new configuration of the aerodynamic profiles.

Abstract: A method for reducing the vibration levels likely to occur, in a turbine engine including a first and a second bladed disk forming a propfan of contrarotating disks, when the two disks are traversed by a gaseous fluid, because of the turbulence of aerodynamic origin generated by the second bladed disk on the first bladed disk is disclosed. The method includes defining an initial configuration of the blades, calculating the synchronous forced response on the first bladed disk as a function of the harmonic excitation force generated by the second bladed disk expressed as a linear function of the generalized aerodynamic force for the mode in question; for stacked sections of one of the two disks, determining a tangential geometric offset value ? of the individual aerodynamic profile to reduce the term corresponding to the generalized aerodynamic force; and applying a new configuration to the blades.

Abstract: A method for reducing vibration levels in a turbomachine including at least a first and a second bladed wheel, due to aerodynamic perturbations that are produced by the second bladed wheel or an obstacle on the first bladed wheel is disclosed. The method includes: defining an initial configuration of the blades; calculating the synchronous forced response on the first bladed wheel as a function of the harmonic excitation force produced by the second bladed wheel expressed in the form of a linear function of the generalized aerodynamic force for the mode considered; determining a geometric tangential shift value ? for the stacked cross sections of one of the two wheels to reduce the corresponding term to the generalized aerodynamic force. The set of cross sections with the tangential shifts thus defines a new configuration of the blades of one of the two wheels.

Abstract: An impeller including a blade, a support of the blade which extends substantially radially, at least one intermediate part extending, in a substantially axial direction, between the blade and the support of the blade, and at least one damping device placed on at least one face of the intermediate part is disclosed. The damping device is segmented in an axial and/or circumferential direction into at least two elementary damping devices.

Abstract: A lever for rotating about its pivot a turbomachine variable-pitch stator vane: including a first zone for attachment to a lever drive member, a second zone for attachment to the variable-pitch stator vane, and a third zone of elongate shape between the first zone and the second zone is disclosed. A vibration-damping laminate is applied to at least one surface portion of at least one of the zones of the lever. The laminate includes at least one layer of viscoelastic material in contact with the surface portion and a backing layer of rigid material.

Abstract: A cylindrical casing for a turbomachine that is suitable for receiving a rotor fitted with at least one bladed wheel is disclosed. The casing includes a device for preventing instability during contact between the casing and the bladed wheel. The device includes a succession of elements disposed around the circumference of the casing, and presenting different stiffnesses between two adjacent elements. The number of elements having the same stiffness not being equal to a multiple of the wave number of the vibratory mode of the bladed wheel that is to be inhibited. The invention is applicable to a compressor, a turbine, or a fan.

Abstract: A turbomachine stator forming a stator vane ring or upstream guide vane element including a plurality of vanes placed radially between a first inner ring and a second outer ring is disclosed. The two rings are concentric and the second ring has a cylindrical outer surface portion. The stator is characterized in that, on the outer surface portion, at least one vibration-damping laminate is attached. The laminate includes at least one layer of viscoelastic material in contact with the surface portion and one counterlayer of rigid material.

Abstract: The invention relates to a turbomachine blade comprising an aerodynamic surface made of a composite material and extending in a first direction between a leading edge and a trailing edge, and in a second direction between a root and a tip of the blade. The blade includes solid metal reinforcement that is adhesively bonded to the leading edge of its aerodynamic surface, which reinforcement extends along the first direction beyond the leading edge of the aerodynamic surface and along the second direction between the root and the tip, and includes at least one recess for absorbing at least a portion of the energy that results from an impact of a foreign body against the leading edge of the blade.

Abstract: The invention relates to a turbomachine thermomechanical part forming a body of revolution about a longitudinal axis, and including at least one abradable ring for a labyrinth seal. In characteristic manner, the abradable ring is made up of angular sectors that present different stiffnesses between adjacent pairs of sectors. The invention is applicable to a compressor, a turbine, or to a rotor and stator assembly.

Abstract: A hollow shaft of a turbomachine including a cylindrical wall with an inner surface portion and at one end a member for attachment to a rotor disk of the turbomachine is disclosed. The shaft also includes a damping device wherein at least one vibration-damping laminate is attached to the inner surface portion. The laminate includes at least one layer of viscoelastic material in contact with the surface portion and a counterlayer of rigid material.

Abstract: A diffuser-nozzle assembly for mounting at an outlet from a compressor in a turbomachine, the assembly including a nozzle including two substantially cylindrical walls, a radially inner wall and a radially outer wall that are connected together by radial vanes. The walls of the nozzle are extended downstream beyond the radial vanes and the radial spacing therebetween varies downstream from the vanes to be at a minimum substantially in register with the vanes and at a maximum between the vanes.

Abstract: The present invention relates to a blade made of composite, comprising a vane formed of woven filaments impregnated with a thermosetting resin with a protective element in the region of the leading edge of the vane comprising a part in the form of a rigid strip, said strip being secured to the vane. The blade is characterized in that at least one layer of a viscoelastic material is at least partially interposed between said rigid strip and the vane so as to form, with the protective element, a means of damping the vibrations of the vane.

Abstract: The invention relates to a turbomachine thermomechanical part forming a body of revolution about a longitudinal axis, and including at least one abradable ring for a labyrinth seal. In characteristic manner, the abradable ring is made up of angular sectors that present different stiffnesses between adjacent pairs of sectors. The invention is applicable to a compressor, a turbine, or to a rotor and stator assembly.

Abstract: A sector of a compressor guide vanes assembly or a sector of a turbomachine nozzle assembly. It comprises an inner ring sector (4), an outer ring sector (6) and a multitude of blades (8) connecting the inner ring sector (4) to the outer ring sector (6). The outer ring sector (6) or the inner ring sector (4) comprises radial cuts (10) situated between two consecutive blades (8) in such a way as to split them into the same number of elementary sectors as there are blades. Housings (14) are provided, secant to the radial cuts (10), damping inserts (16) being positioned in said housings.

Abstract: The present invention relates to a blade made of composite material (100) comprising an airfoil (100A) formed of filaments or fibers, optionally woven, impregnated with a heat-curable resin, with an intrados wall and an extrados wall between the leading edge and the trailing edge. It is characterized in that a device for damping the vibrations is incorporated in one or other of the intrados and extrados walls, and is formed of at least one layer made of viscoelastic material (111) and a layer made of rigid material (110), these layers being superposed. According to one embodiment, the layer made of rigid material comprises a first zone (1101) and a second zone (1102), the layer made of viscoelastic material (111) being interposed between the airfoil and said first zone (1101) of the rigid layer (110), and said second zone (1102) of the rigid layer being attached to the wall of the airfoil (100A) without interposition of viscoelastic material.

Abstract: The present invention relates to a method for reducing the vibration levels likely to occur, in a turbine engine comprising a first and a second bladed disk forming a propfan of contrarotating disks, when the two disks are traversed by a gaseous fluid, because of the turbulence of aerodynamic origin generated by the second bladed disk on the first bladed disk. The method comprises the following steps during the design of said two bladed disks: an initial configuration of the blades is defined, the synchronous forced response is calculated on the first bladed disk as a function of the harmonic excitation force generated by the second bladed disk expressed in the form of a linear function of the generalized aerodynamic force for the mode in question; for stacked sections of one of the two disks, a tangential geometric offset value ? of the individual aerodynamic profile is determined so as to reduce the term corresponding to the generalized aerodynamic force.

Abstract: The present invention relates to a method for reducing the vibration levels capable of occurring, in a turbine engine comprising at least one propeller and one coupling structure of the turbine engine, because of the turbulence of aerodynamic origin generated by the coupling structure on the propeller. The method comprises the following steps during the design of the aerodynamic profiles of the propeller and of the coupling structure: an initial configuration of the aerodynamic profiles is defined, the synchronous forced response on the propeller is calculated as a function of the force of harmonic excitation generated by the coupling structure expressed in the form of a linear function of the generalized aerodynamic force for the mode in question; for stacked sections of one of the propeller or of the coupling structure, a tangential geometric offset value ? of the individual aerodynamic profiles is determined in order to reduce the term corresponding to the generalized aerodynamic force.