# US 2010/0166549 A1 · Methods, systems and/or apparatus relating to inducers for turbine engines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166549 A1 - Document ID: US20100166549A1 - Status: Published application - Kind: A1 - Application number: 12/346,255 - Filed: 2008-12-30 - Published: 2010-07-01 - Earliest claimed: 2008-12-30 - Assignees: General Electric Company - Inventors: Anca Hatman - Web page: https://patentgrep.com/patent/US20100166549A1 ## CPC - F01D 5/081: {Cooling fluid being directed on the side of the rotor disc or at the roots of the blades (F01D5/087 takes precedence)} - F01D 5/082: {on the side of the rotor disc} - F05D 2260/14: Preswirling - F05D 2260/97: Reducing windage losses - 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) - 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 An inducer that includes a profiled throat. In some embodiments, the inducer includes a conical shape upstream of the profiled throat with a relatively large circular inlet that narrows to the profiled throat and, downstream of the profiled throat, a downstream section that broadens from the profiled throat. The profiled throat may include an approximate convergent-divergent nozzle geometry. ## Claims ### Claim 1 An inducer that includes a profiled throat. ### Claim 2 (depends on 1) The inducer according to claim 1, wherein: the inducer comprises a conical shape upstream of the profiled throat with a relatively large circular inlet that narrows to the profiled throat and, downstream of the profiled throat, a downstream section that broadens from the profiled throat; and the inducer comprises one of a radial-axial inducer, a purely axial inducer, and a purely radial inducer. ### Claim 3 (depends on 1) The inducer according to claim 1, wherein the profiled throat comprises an approximate convergent-divergent nozzle geometry. ### Claim 4 (depends on 1) The inducer according to claim 1, wherein the profiled throat comprises an upstream narrowing, a narrow mid-section, and a downstream broadening. ### Claim 5 (depends on 4) The inducer according to claim 4, wherein: the upstream narrowing of the profiled throat comprises an approximate smooth conical shape that is broader at an upstream end than it is at a downstream end; and the downstream broadening of the profiled throat comprises an approximate smooth conical shape that is narrower at an upstream end than it is at a downstream end. ### Claim 6 (depends on 5) The inducer according to claim 5, wherein the smooth conical shape of the upstream narrowing and the downstream broadening comprises one of a curved conical shape and a linear conical shape. ### Claim 7 (depends on 5) The inducer according to claim 5, wherein the narrow mid-section comprises the narrowest section through the throat and resides between the upstream narrowing and downstream broadening. ### Claim 8 (depends on 5) The inducer according to claim 5, the narrow mid-section comprises the most narrow passageway through the inducer, wherein the most narrow passageway comprises the passageway with the least cross-sectional area. ### Claim 9 (depends on 5) The inducer according to claim 5, wherein the narrow mid-section comprises an inward radial crest between the narrowing of the upstream narrowing and the downstream broadening. ### Claim 10 (depends on 5) The inducer according to claim 5, wherein the narrow mid-section has an extended axial length of an approximate constant cross-sectional area. ### Claim 11 (depends on 2) The inducer according to claim 2, wherein the profiled throat is originally configured to provide a desired minimum flow level therethrough. ### Claim 12 (depends on 11) The inducer according to claim 11, wherein the desired minimum flow level comprises the minimum flow level that is believed necessary to satisfy an operational criterion. ### Claim 13 (depends on 2) The inducer according to claim 2, wherein the downstream section of the inducer is configured to accommodate a desired maximum flow therethrough. ### Claim 14 (depends on 13) The inducer according to claim 13, wherein the desired maximum flow level comprises the maximum flow level that is believed necessary to satisfy an operational criterion. ### Claim 15 (depends on 1) The inducer according to claim 1, wherein the inducer is a radial-axial inducer and is configured to direct and accelerate a flow of cooling gas in a gas turbine engine. ### Claim 16 A method of operating a gas turbine engine, the method including the steps of: a) installing within the turbine engine an inducer that comprises: a profiled throat that includes an approximate convergent-divergent nozzle geometry, wherein the profiled throat is configured to provide a desired minimum flow level therethrough; a conical shape upstream of the profiled throat with a relatively large circular inlet that narrows to the profiled throat; and downstream of the profiled throat, a downstream section, wherein the downstream section of the inducer is configured to accommodate a desired maximum flow level therethrough; b) upon operating the turbine engine after the installation of the inducer, determining if the flow level through the inducer satisfies an operational criterion; c) if it is determined that the flow level through the inducer does not satisfy the operational criterion and that a greater flow level is needed, machining the profiled throat to increase the cross-sectional area therethrough. ### Claim 17 (depends on 16) The method of claim 16, wherein the profiled throat comprises an upstream narrowing, a narrow mid-section, and a downstream broadening. ### Claim 18 (depends on 17) The method of claim 17, wherein: the upstream narrowing of the profiled throat comprises an approximate smooth conical shape that is broader at an upstream end than it is at a downstream end; and the downstream broadening of the profiled throat comprises an approximate smooth conical shape that is narrower at an upstream end than it is at a downstream end. ### Claim 19 (depends on 18) The method of claim 18, wherein the smooth conical shape of the upstream narrowing and the downstream broadening comprises one of a curved conical shape and a linear conical shape. ### Claim 20 (depends on 18) The method of claim 18, wherein the narrow mid-section comprises the narrowest section through the throat and resides between the upstream narrowing and downstream broadening.