# US 10,865,645 B2 · Method for manufacturing a turbomachine fan having a reduced noise level at multiple rotational frequencies of said turbomachine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,645 B2 - Document ID: US10865645B2 - Status: Granted - Kind: B2 - Application number: 15/580,243 - Filed: 2016-06-08 - Published: 2018-06-21 - Granted: 2020-12-15 - Earliest claimed: 2015-06-08 - Assignees: Safran Aircraft Engines - Applicants: Safran Aircraft Engines - Inventors: Anthony Bernard Germain Lafitte; Jean-Frederic Pierre Joseph Bruhat; Frederic Jean-Bernard Pouzadoux; Jean-Michel Roux - Web page: https://patentgrep.com/patent/US10865645B2 ## CPC - F01D 5/027: {Arrangements for balancing (for balancing rotating bodies in general F16F15/32; for compensating imbalance G01M1/36)} - F01D 5/141: {Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147)} - F01D 5/16: for counteracting blade vibration - F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments} - F04D 29/324: {Blades} - F04D 29/327: {with non identical blades} - F04D 29/644: {especially adapted for elastic fluid pumps} - F04D 29/668: {damping or preventing mechanical vibrations} - F04D 29/662: {Balancing of rotors (compensating imbalance G01M1/36)} - F05D 2220/36: specially adapted for the fan of turbofan engines - F05D 2240/301: Cross-sectional characteristics - F05D 2240/302: characteristics related to shock waves, transonic or supersonic flow - F05D 2240/303: related to the leading edge of a rotor blade - F05D 2240/304: related to the trailing edge of a rotor blade - F05D 2240/40: Use of a multiplicity of similar components - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F05D 2260/961: by mistuning rotor blades or stator vanes with irregular interblade spacing, airfoil shape - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract The invention relates to a method (100) for manufacturing a turbomachine fan comprising a plurality of blades mounted on a disc extending along a longitudinal axis, said method comprising the following steps of: —measuring (102) at least one structural parameter of each of the blades in the cold state, and, for each of the blades, estimating (103) at least one structural parameter in operation relating to a blade from the structural parameter(s) measured on said blade in the cold state, —determining (104) an optimal sequence of the blades around the disc from the structural parameters estimated in operation for each of the blades, and —mounting (105) the blades on the disc in the optimal sequence thus determined. ## Claims ### Claim 1 A method for manufacturing a turbomachine fan including a plurality of blades mounted on a disk extending around a longitudinal axis, said method comprising: measuring in a cold state, when said turbomachine fan is in a non-operational state, at least one structural parameter on each of the plurality of blades, for each of the plurality of blades, estimating at least one structural parameter relating to each said blade when said turbomachine is in an operational state from the at least one measured structural parameter for each said blade, determining an optimal sequence (ORD) of the plurality of blades around the disk from the at least one estimated structural parameter obtained for each of the plurality of blades, mounting the plurality of blades on the disk in the optimal sequence (ORD) thus determined, wherein when said turbomachine fan is in said operational state, a reduced noise level at multiple rotational frequencies (FMR) is obtained as compared to a noise level that would be produced by a turbomachine fan in which the plurality of blades are mounted in a sequence determined based on said at least one measured structural parameter on each of the plurality of blades. ### Claim 2 (depends on 1) The method according to claim 1, wherein the estimation in operation of the at least one structural parameter of each said blade is performed from the structural parameter(s) measured in the cold state on each said blade and from a predictive response surface previously generated by a response surface method (RSM) to which are applied the at least one structural parameter measured in the cold state of each said blade. ### Claim 3 (depends on 1) The method according to claim 1, wherein the at least one structural parameter measured in the cold state on each said blade are selected from at least one of: a position of the center of gravity (XGs, YGs) of a section of each said blade at a cross-sectional height (hc) of each said blade, and a stagger angle (CHORD_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a leading edge angle (LE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a trailing edge angle (TE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade. ### Claim 4 (depends on 1) The method according to claim 1, wherein the at least one structural parameter measured in the cold state on each said blade is selected from at least one of: a position of the center of gravity (XGs, YGs) of a section of each said blade at a cross-sectional height (hc) of each said blade, and a length (L, L1, L2) of the chord of each said blade at the cross-sectional height (hc) of each said blade, and a stagger angle (CHORD_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a leading edge angle (LE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a trailing edge angle (TE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a total height (H) of each said blade, and at least one of a radial (R), an (A) and a tangential (T) static moment of each said blade, and a mass of each said blade. ### Claim 5 (depends on 1) The method according to claim 1, wherein the at least one structural parameter estimated in operation of each said blade is selected from at least one of: a stagger angle (CHORD_ANGLE) of each said blade at a cross-sectional height (hc) of each said blade, and a leading edge angle (LE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a trailing edge angle (TE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade. ### Claim 6 (depends on 1) The method according to claim 1, wherein the at least one structural parameter estimated in operation of each said blade are selected from at least one of: a position of the center of gravity (XGs, YGs) of a section of each said blade at a cross-sectional height (hc) of each said blade, and a length (L, L1, L2) of the chord of each said blade at the cross-sectional height (hc) of each said blade, and a stagger angle (CHORD_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a leading edge angle (LE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a trailing edge angle (TE_ANGLE) of each said blade at the cross-sectional height (hc) of each said blade, and a total height (H) of each said blade, and at least one of a radial (R), an xial (A) and a tangential (T) static moment of each said blade, and a mass of each said blade. ### Claim 7 (depends on 3) The method according to claim 3, wherein the cross-sectional height (hc) is taken as 90% of a total height (H) of each said blade from a root of each said blade. ### Claim 8 (depends on 1) A turbomachine fan obtained by the implementation of the manufacturing method according to claim 1. ### Claim 9 (depends on 8) A turbomachine comprising the fan according to claim 8.