# US 7,464,552 B2 · Acoustically stiffened gas-turbine fuel nozzle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,464,552 B2 - Document ID: US7464552B2 - Status: Granted - Kind: B2 - Application number: 10/884,467 - Filed: 2004-07-02 - Published: 2006-01-05 - Granted: 2008-12-16 - Earliest claimed: 2004-07-02 - Assignees: Siemens Energy, Inc. - Inventors: Stanley S. Sattinger - Web page: https://patentgrep.com/patent/US7464552B2 ## CPC - F02C 7/222: {Fuel flow conduits, e.g. manifolds} - F23M 20/005: {Noise absorbing means} - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F05D 2270/14: to control thermoacoustic behaviour in the combustion chambers - F23R 2900/00014: Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F23M: CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16) ## Abstract Under certain conditions, the fuel delivery system can contribute to the formation of strong dynamic pressures in the combustor of a turbine engine. Embodiments of the invention provide a system for dynamically stiffening the fuel supply passage to suppress damaging combustion dynamics. To that end, a Helmholtz resonator can be placed along and in branched relation to the fuel supply passage. The resonator can produce the effect of adding a pressure release opening at a selected location in the fuel line, causing a shift in the fuel line pressure wave pattern that blocks fuel flow fluctuations at the outlet of the fuel passage at the frequency of the oscillation. The pressure wave shift results in a shifting of the volume velocity wave pattern. Ideally, the resonator can be positioned along the flow path such that the volume velocity of the fuel at the fuel passage exit is minimized. ## Claims ### Claim 1 An acoustically stiffened fuel supply system for a turbine engine comprising: at least one turbine engine combustion chamber; a fuel supply passage for receiving a pressurized gas fuel therein, the passage having an outlet adapted to discharge fuel into the combustion chamber, the fuel supply passage being defined at least in part by a t-shaped pipe having an open inlet end, an opposing open outlet end and an open branch end disposed therebetween, the t-shaped pipe having an internal passage, wherein the fuel in the passage has an associated volume velocity wave and an associated pressure wave, the pressure wave being substantially 90 degrees out of phase with the volume velocity wave; a plug having a plurality of openings therein, the plug being secured to the branch end so as to substantially close the open branch end, the plug including an inner surface and an outer surface, wherein the inner surface includes at least one baffle extending therefrom, whereby the baffle reduces grazing flow of fuel over the inner surface of the plug; and a housing enclosing at least a portion of the branch end so as to define a volume therebetween, wherein the openings permit fluid communication between the internal passage of the t-shaped pipe and the volume and wherein the openings are the only manner of fluid communication with the volume, whereby a resonator assembly is formed, wherein the resonator shifts the pressure wave in the fuel supply passage such that a pressure antinode occurs substantially at the outlet, whereby the volume velocity wave amplitude of the fuel is reduced at the passage outlet, such that the combustion oscillations in the combustor that are attributable to the fuel passage are suppressed. ### Claim 2 (depends on 1) The system of claim 1 wherein the fuel supply passage is defined by at least a fuel supply line and a fuel nozzle, wherein the fuel nozzle is located downstream of the fuel supply line and has a discharge face that defines the outlet of the fuel supply passage. ### Claim 3 (depends on 2) The system of claim 2 wherein the resonator assembly is provided between the fuel supply line and the fuel nozzle. ### Claim 4 (depends on 2) The system of claim 2 wherein the resonator assembly is located in the fuel supply line upstream of the fuel nozzle. ### Claim 5 (depends on 1) The system of claim 1 wherein the combustor is a diffusion-type combustor. ### Claim 6 (depends on 1) The system of claim 1 wherein at least a portion of the plug is received within the branch end. ### Claim 7 (depends on 1) The system of claim 1 wherein the volume velocity wave amplitude is reduced to substantially zero substantially at the outlet. ### Claim 8 A resonator for a turbine engine fuel supply line comprising: a t-shaped pipe having opposing inlet and outlet ends and an open branch end disposed therebetween, the t-shaped pipe having an internal passage; a plug having a plurality of openings therein, the plug being secured to the branch end so as to substantially close the open branch end; and a housing enclosing at least a portion of the branch end so as to define a volume therebetween, wherein the openings in the plug permit fluid communication between the internal passage of the t-shaped pipe and the volume and wherein the openings are the only manner of fluid communication with the volume. ### Claim 9 (depends on 8) The resonator of claim 8 wherein the inlet and outlet ends are adapted for fluid connection to a fuel passage. ### Claim 10 (depends on 8) The resonator of claim 8 wherein at least a portion of the plug is received within the branch end. ### Claim 11 (depends on 8) The resonator of claim 8 wherein the plug includes an inner surface and an outer surface, wherein the inner surface includes at least one baffle extending therefrom, whereby the baffle reduces grazing flow over the inner surface of the plug. ### Claim 12 (depends on 11) The resonator of claim 11 wherein the openings in the plug are offset from the baffle. ### Claim 13 (depends on 8) The resonator of claim 8 wherein at least a portion of the housing is thermally insulated. ### Claim 14 (depends on 8) The resonator of claim 8 wherein the openings in the plug are configured to provide acoustic stiffening at a specified frequency. ### Claim 15 (depends on 8) The resonator of claim 8 wherein the branch end is substantially perpendicular to the inlet and outlet ends.