# US 2017/0284674 A1 · Closed trapped vortex cavity pilot for a gas turbine engine augmentor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284674 A1 - Document ID: US20170284674A1 - Status: Published application - Kind: A1 - Application number: 15/085,165 - Filed: 2016-03-30 - Published: 2017-10-05 - Earliest claimed: 2016-03-30 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: David Andrew Perveiler - Web page: https://patentgrep.com/patent/US20170284674A1 ## CPC - F23R 3/20: incorporating fuel injection means - F02C 7/222: {Fuel flow conduits, e.g. manifolds} - F02C 7/264: Ignition - F02K 3/08: with supplementary heating of the working fluid; Control thereof (control of fuel supply therefor F02C9/26) - F23R 3/002: {Wall structures (F23R3/02 and F23R3/007 take precedence)} - F23R 3/06: Arrangement of apertures along the flame tube - F23R 3/283: {Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances} - F23R 3/343: {Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion (ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00)} - F23R 3/42: characterised by the arrangement or form of the flame tubes or combustion chambers - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - 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) - 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) - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A closed trapped vortex apparatus includes: a tubular structure having a structural wall, the structural wall forming a cavity within the tubular structure, the structural wall having a lower boundary wall forming a boundary between the cavity and a core flow passage; at least one driver hole passing through the structural wall; an ignition source communicating with the cavity; a fuel source communicating with the cavity; and a plurality of flame tubes extending through the lower boundary wall of the tubular structure at preselected locations so as to provide communication between the cavity and the core flow passage. ## Claims ### Claim 1 A closed trapped vortex apparatus, comprising: a tubular structure having a structural wall, the structural wall forming a cavity within the tubular structure, the structural wall having a lower boundary wall forming a boundary between the cavity and a core flow passage; at least one driver hole passing through the structural wall; an ignition source communicating with the cavity; a fuel source communicating with the cavity; and a plurality of flame tubes extending through the lower boundary wall of the tubular structure at preselected locations so as to provide communication between the cavity and the core flow passage. ### Claim 2 (depends on 1) The apparatus of claim 1 further comprising a plurality of cooling holes formed in the structural wall, the cooling holes passing through the structural wall at an acute angle to a surface of the structural wall. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the ignition source comprises an igniter extending through the structural wall into the cavity. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the fuel source comprises a spraybar extending through the structural wall into the cavity. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the tubular structure extends at least partially around the core flow passage. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the tubular structure extends 360° around the core flow passage. ### Claim 7 (depends on 1) The apparatus of claim 1 wherein the flame tubes are configured as elongated slots. ### Claim 8 A gas turbine engine exhaust apparatus, comprising: an exhaust casing; a combustion liner spaced radially inward of the exhaust casing; a cooling duct defined by boundaries established radially inward by a first face of the combustion liner, and radially outward by the exhaust casing; a core duct defined at least in part by a second face of the combustion liner; and an augmentor apparatus, including: a radial spraybar radially extending into the core duct, the spraybar including fuel tubes in communication with a fuel source, the spraybar configured to introduce fuel into the core duct, a closed trapped vortex apparatus disposed within the cooling duct, the closed trapped vortex apparatus comprising: a tubular structure having a structural wall, the structural wall forming a cavity within the tubular structure, the structural wall having a lower boundary wall forming a boundary between the cavity and the core duct, at least one driver hole passing through the structural wall, an ignition source communicating with the cavity; a fuel source communicating with the cavity; and a plurality of flame tubes extending through the lower boundary wall of the tubular structure at preselected locations providing communication between the cavity and the core duct; wherein the closed trapped vortex cavity apparatus of the augmentor apparatus is located radially outward of the combustor liner. ### Claim 9 (depends on 8) The apparatus of claim 8 further comprising a plurality of cooling holes formed in the structural wall, the cooling holes passing through the structural wall at an acute angle to a surface of the structural wall. ### Claim 10 (depends on 8) The apparatus of claim 8 wherein the ignition source comprises an igniter extending through the structural wall into the cavity. ### Claim 11 (depends on 8) The apparatus of claim 8 wherein the fuel source comprises a spraybar extending through the structural wall into the cavity. ### Claim 12 (depends on 8) The apparatus of claim 8 further comprising: a diffuser liner spaced radially inward of the exhaust casing and upstream of the combustion liner, the diffuser liner having a first face cooperating with the combustion liner to define the core duct, and an opposed second face defining a portion of the cooling duct; and a hollow exhaust vane radially extending into the core duct from the diffuser liner, wherein the exhaust vane is in fluid communication with the cooling duct and includes injection holes configured to inject air into the core duct. ### Claim 13 (depends on 8) The apparatus of claim 8 wherein the tubular structure extends at least partially around the core flow radially outward of the combustion liner. ### Claim 14 (depends on 8) The apparatus of claim 8 wherein the tubular structure extends 360° around the core flow radially outward of the combustion liner. ### Claim 15 (depends on 8) The apparatus of claim 8 wherein the flame tubes are configured as elongated slots. ### Claim 16 A method of providing pilot ignition for a gas turbine engine augmentor, comprising: passing a core flow containing oxygen through a core duct; introducing fuel into the core flow to define a combustible mixture; maintaining a pilot flame in a closed trapped vortex combustion pattern at a location outside the core duct; communicating at least one of the pilot flame and hot gases from the closed trapped vortex to the core flow at one or more discrete locations around the periphery of the core duct, so as to ignite the combustible mixture. ### Claim 17 (depends on 16) The method of claim 16 wherein the trapped vortex combustion pattern comprises a single vortex. ### Claim 18 (depends on 16) The method of claim 16 wherein the trapped vortex combustion pattern comprises two or more vortices. ### Claim 19 (depends on 16) The method of claim 16 wherein the fuel is introduced into the core flow through a radial spray bar disposed upstream of a radial flameholder, wherein the spray bar and the flame holder are disposed upstream of the pilot flame.