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 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: 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: The present invention relates to a hollow shaft of a turbomachine comprising a cylindrical wall with an inner surface portion and at one end a member for attachment to a rotor disk of the turbomachine. The shaft also comprises a damping device wherein at least one vibration-damping laminate is attached to said inner surface portion, the laminate comprising at least one layer of viscoelastic material in contact with said surface portion and a counterlayer of rigid material.

Abstract: The present invention relates to a turbomachine stator forming a stator vane ring or upstream guide vane element comprising a plurality of vanes placed radially between a first inner ring and a second outer ring, the two rings being concentric, the second ring having a cylindrical outer surface portion. The stator is characterized in that, on said outer surface portion, at least one vibration-damping laminate is attached, the laminate comprising at least one layer of viscoelastic material in contact with said surface portion and one counterlayer of rigid material.

Abstract: The impeller comprises a blade and a support of said blade which extend substantially radially. It also comprises at least one intermediate part extending, in a substantially axial direction, between said blade and said support of the blade, and at least one damping means placed on at least one face of said intermediate part. The damping means is segmented in an axial and/or circumferential direction into at least two elementary damping means.

Abstract: The present invention concerns a method for reducing vibration levels likely to occur in a turbomachine comprising at least a first and a second bladed wheel, where the two wheels are moving relative to one another about an axis of rotation and a gaseous fluid is passing over them, due to perturbations of an aerodynamic origin that are produced by the second bladed wheel or an obstacle on the first bladed wheel. The method includes the following steps in the design of said two bladed wheels: an initial configuration of the blades is defined; the synchronous forced response on the first bladed wheel is calculated 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; a geometric tangential shift value ? is determined for the stacked cross sections of one of the two wheels so as to reduce the corresponding term to the generalized aerodynamic force.