# US 10,309,315 B2 · Variable area nozzle assisted gas turbine engine restarting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,315 B2 - Document ID: US10309315B2 - Status: Granted - Kind: B2 - Application number: 15/083,752 - Filed: 2016-03-29 - Published: 2016-10-06 - Granted: 2019-06-04 - Earliest claimed: 2016-03-29 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Ashok K. Jain; Michael Winter - Web page: https://patentgrep.com/patent/US10309315B2 ## CPC - F02C 7/262: Restarting after flame-out - F01D 25/24: Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) - F02C 9/16: Control of working fluid flow (F02C9/48 takes precedence; control of air-intake flow F02C7/057) - F02K 1/06: Varying effective area of jet pipe or nozzle (by using fluid jets to influence the jet flow F02K1/30) - F02K 1/1207: {of one series of flaps hinged at their upstream ends on a fixed structure (F02K1/1215 - F02K1/1292 take precedence)} - F02K 1/15: Control or regulation - F02K 3/075: controlling flow ratio between flows - F05D 2220/32: in gas turbines - F05D 2260/85: Starting - F05D 2270/092: in particular blow-out and relight - 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) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An example turbofan engine starting system includes a core nacelle housing a compressor and a turbine. The core nacelle is disposed within a fan nacelle. The fan nacelle includes a turbofan. A bypass flow path downstream from the turbofan is arranged between the two nacelles. A controller is programmed to manipulate the nozzle exit area to facilitate startup of the engine. In one example, manipulates the nozzle exit area using nozzles, in response to an engine shutdown condition. The nozzles open and close to adjust the nozzle exit area. ## Claims ### Claim 1 A turbofan engine restarting system, comprising: a core nacelle housing a compressor and a turbine; a fan nacelle housing a fan section that is arranged upstream from said core nacelle; a bypass flow path downstream from said fan section and arranged between said core and fan nacelles, said bypass flow path including an effective nozzle exit area that defines an axis; a controller programmed to selectively increase and decrease said effective nozzle exit area to facilitate restart of said engine during flight in air, wherein said effective nozzle area is increased when said nozzle effective area is not a maximum effective nozzle area; a starter for increasing a rotational speed of said fan section; and a control device arranged to receive a command from said controller in response to an engine condition, said control device changing said effective nozzle exit area provided between said core and fan nacelles in response to said command. ### Claim 2 (depends on 1) The turbofan engine restarting system of claim 1, wherein a plurality of flaps are arranged about the axis, said controller initiates movement of at least some of said flaps radially away from said axis and from a position suitable for aircraft cruising operations to increase said effective nozzle exit area, and initiates movement of at least some of said flaps radially toward said axis to decrease said effective nozzle exit area. ### Claim 3 (depends on 1) The turbofan engine restarting system of claim 1, wherein the increase occurs when the effective nozzle exit area of the bypass flow path is not a maximum effective nozzle exit area of the bypass flowpath. ### Claim 4 (depends on 1) The turbofan engine restarting system of claim 1, wherein said control device increases or decreases said effective nozzle exit area in response to said command. ### Claim 5 (depends on 1) The turbofan engine restarting system of claim 1, wherein said control device increases a mass flow rate of air through said bypass flow path. ### Claim 6 (depends on 1) The turbofan engine restarting system of claim 1, wherein an increased mass flow rate of air through said bypass flow path increases a windmilling speed of said fan section. ### Claim 7 (depends on 1) The turbofan engine restarting system of claim 1, comprising a driver for initiation by an aircraft operator and in communication with said controller, said controller sending said command in response to actuation of said driver. ### Claim 8 (depends on 1) The turbofan engine restarting system of claim 1, wherein said engine condition includes a rotational speed of a portion of said engine. ### Claim 9 (depends on 1) The turbofan engine restarting system of claim 1, including at least one nozzle flap disposed on said fan nacelle operative to control said effective nozzle exit area. ### Claim 10 A method of restarting a turbofan engine comprising the steps of: a) detecting a shutdown of a turbofan engine during flight in air; b) selectively increasing and decreasing an effective nozzle exit area from a bypass flow path within the engine in response to the shutdown during a flight in air to establish a desired condition for a startup of the engine during the flight in air, the increasing and decreasing achieved by changing a physical area of an exit nozzle, the exit nozzle provided by a turbofan nacelle surrounding a fan section and a core nacelle; and c) increasing the rotational speed of a fan section of the engine using a starter. ### Claim 11 (depends on 10) The method of restarting a turbofan engine according to claim 10, wherein a controller commands a control device to change the effective nozzle exit area. ### Claim 12 (depends on 11) The method of restarting a turbofan engine according to claim 11, wherein the controller commands the control device based on a rotational speed of a rotor. ### Claim 13 (depends on 11) The method of restarting a turbofan engine according to claim 11, wherein the controller commands the control device based on at least one of an airflow rate or an air pressure within the engine. ### Claim 14 (depends on 10) The method of restarting a turbofan engine according to claim 10, wherein said step (b) includes increasing the effective nozzle exit area to increase a rotational speed of a rotor within the engine. ### Claim 15 (depends on 10) The method of restarting a turbofan engine according to claim 10, wherein said step (b) includes decreasing the effective nozzle exit area to increase a mass flow rate of air through a portion of the engine. ### Claim 16 (depends on 10) The method of restarting a turbofan engine according to claim 10, wherein said step (b) includes increasing the effective nozzle exit area and then decreasing the effective nozzle exit area to the increase mass flow rate of air through a portion of the engine. ### Claim 17 (depends on 10) The method of restarting a turbofan engine according to claim 10, including selectively increasing combinations of altitude and airspeed suitable for restarting the turbofan engine. ### Claim 18 (depends on 10) The method of restarting a turbofan engine according to claim 10, wherein the increasing occurs when the effective nozzle exit area of the bypass flow path is not a maximum effective nozzle exit area of the bypass flowpath.