Reduced Noise Gas Turbine Engine System and Supersonic Exhaust Nozzle System Using Elector to Entrain Ambient Air

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(12) (io) Patent No.:

United States Patent US 9,714,608 B2

(45) Jul.

Sokhey et al. Date of Patent: 25,2017

(54) REDUCED NOISE GAS TURBINE ENGINE (52) U.S. Cl.

CPC .................. F02C 3/04 (2013.01); F02K 1/36 SYSTEM AND SUPERSONIC EXHAUST (2013.01); F02K 1/383 (2013.01); F02K 1/386 NOZZLE SYSTEM USING ELECTOR TO (2013.01); F02K 3/025 (2013.01); F02K 3/077 ENTRAIN AMBIENT AIR (2013.01) (75) Inventors: Jagdish S. Sokhey, Indianapolis, IN (58) Field of Classification Search CPC ..... F02K 1/06; F02K 1/12; F02K 1/28; F02K (US); Anthony E. Pierluissi, 1/32; F02K 1/36; F02K 1/48; F02K 1/70; Indianapolis, IN (US) (Continued) (73) Assignee: Rolls-Royce North American Technologies, Inc., Indianapolis, IN (56) References Cited (US) U.S. PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term ofthis 3,749,316 A * 7/1973 Tontini ...................... F02K 1/36 patent is extended or adjusted under 35 181/215 U.S.C. 154(b) by 75 days.

4,135,363 A * 1/1979 Packman ................ F02K 1/386 181/213 (21) Appl. No.: 14/343,155 (Continued) (22) PCT Filed: Sep. 5, 2012 OTHER PUBLICATIONS (86) PCT No.: PCT/US2012/053777 PCT International Search Report completed by the ISA/US on Apr.

30, 2013 and issued in connection with PCT/US2012/053777.

§ 371 (c)(1), (2),(4) Date: May 16, 2014 Primary Examiner Pascal M Bui Pho Assistant Examiner Marc Amar (87) PCT Pub. No.: W02013/077924 (74) Attorney, Agent, or Firm Barnes & Thornburg PCT Pub. Date: May 30, 2013 LLP (65) Prior Publication Data (57) ABSTRACT US 2014/0238043 Al Aug. 28, 2014 One embodiment of the present invention is a unique gas turbine engine system. Another embodiment is a unique exhaust nozzle system for a gas turbine engine. Other Related U.S. Application Data embodiments include apparatuses, systems, devices, hard- (60) Provisional application No. 61/532,298, filed on Sep.

ware, methods, and combinations for gas turbine engine 8, 2011.

systems and exhaust nozzle systems for gas turbine engines.

Further embodiments,forms,features, aspects, benefits, and (51) Int. Cl.

advantages of the present application will become apparent F02K 1/36 (2006.01) from the description and figures provided herewith.

F02C 3/04 (2006.01) (Continued) 17 Claims, 2 Drawing Sheets "-10 R

US 9,714,608 B2

Page 2 (51) Int. Cl.

F02K 1/38 (2006.01) F02K 3/02 (2006.01) F02K 3/077 (2006.01) (58) Field of Classification Search CPC . F02K 1/72; F02K 3/025; F02K 3/077; F02K 1/38; F02K 1/383; F02K 1/386 See application file for complete search history.

(56) References Cited U.S. PATENT DOCUMENTS 5,154,052 A * 10/1992 Giffin, III ............... F02K 1/006 239/265.13 5,404,713 A * 4/1995 Johnson .................. F02K 1/825 60/204 2005/0047942 At* 3/2005 Grffin, III ............... F02K 3/072 417/423.1 2005/0109012 At* 5/2005 Johnson .................. F02K 3/065 60/226.1 2007/0000232 At* 1/2007 Powell ...................... F02C 3/13 60/204 2010/0154423 At* 6/2010 Olausson ................ F02K 1/383 60/725 2010/0162679 At* 7/2010 Khalid ...................... B64C 7/02 60/204 2010/0162680 Al 7/2010 Khalid * cited by examiner

Jul. Sheet 1 of 2 U.S. Patent 25,2017 US 9,714,608 B2 ~10 34 qj3 16 12 FIG. 1 7n E ` 58

FIG. 2

Jul. Sheet 2 of 2 U.S. Patent 25,2017 US 9,714,608 B2 M ZZ

US 9,714,608 B2

REDUCED NOISE GAS TURBINE ENGINE converging-diverging nozzle in accordance with an embodi- SYSTEM AND SUPERSONIC EXHAUST ment of the present invention.

NOZZLE SYSTEM USING ELECTOR TO DETAILED DESCRIPTION ENTRAIN AMBIENT AIR For purposes of promoting an understanding of the prin- CROSS REFERENCE TO RELATED ciples of the invention, reference will now be made to the APPLICATIONS embodiments illustrated in the drawings, and specific lan- guage will be used to describe the same. It will nonetheless This application is a U.S. national counterpart application 10 be understood that no limitation ofthe scope ofthe invention ofinternational application serial No. PCT/US2012/053777 is intended by the illustration and description of certain filed Sep. 5, 2012, which claims priority under 35 USC embodiments of the invention. In addition, any alterations §II9(e) to U.S. Provisional Patent Application No. 61/532, and/or modifications of the illustrated and/or described 298 filed Sep. 8, 2011, the entire disclosures of which are embodiment(s) are contemplated as being within the scope incorporated herein by reference.

15 of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or GOVERNMENT RIGHTS described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as The present application was made with the United States being within the scope of the present invention.

government support under Contract No. NNCIOCA02C, 20 Referring now to the drawings, and in particular, FIG. 1, awarded by NASA.The United States government may have some aspects of a non-limiting example of a gas turbine certain rights in the present application.

engine system 10 in accordance with an embodiment of the present invention are schematically depicted. In one form, FIELD OF THE INVENTION gas turbine engine 10 is a variable cycle engine. In other 25 embodiments, gas turbine engine 10 may not be a variable The present invention relates to gas turbine engines, and cycle engine. In one form, gas turbine engine 10 is an more particularly, to gas turbine engine systems and super- aircraft engine, and in particular, a turbofan engine. How- sonic nozzles for gas turbine engine systems. ever, it will be understood that in other embodiments, engine 10 may be any other type of gas turbine engine. In still other BACKGROUND 30 embodiments, engine 10 may be a combined cycle engine.

Engine 10 includes a gas generator 12, a low pressure (LP) turbine 14, an adaptive fan 16, an LP shaft 18 and an Gas turbine engine systems and exhaust nozzle systems exhaust nozzle system 20, such as a variable exhaust system for gas turbine engines that effectively provide thrust in having one or more variable nozzles. In one form, adaptive subsonic, transonic and supersonic flight regimes, with 35 fan 16 is powered by LP turbine 14 via LP shaft 18. In other reduced noise output during certain operations, remain an embodiments, adaptive fan 16 may be powered by other area of interest. Some existing systems have various short- turbines in addition to or in place of LP turbine 14. Adaptive comings, drawbacks, and disadvantages relative to certain fan 16 is a turbofan system and drive system configured to applications. Accordingly, there remains a need for further operate one or more turbofan stages at at least two different contributions in this area of technology.

40 speeds relative to the turbine(s) and/or shaft(s) that supply power to the drive system and turbofan system. In some SUMMARY embodiments, a conventional turbofan may be employed in addition to or in place of adaptive fan 16.

One embodiment of the present invention is a unique gas Gas generator 12 includes a compressor 22, a combustor turbine engine system. Another embodiment is a unique 24, a high pressure (HP) turbine 26 and an HP shaft 28.

exhaust nozzle system for a gas turbine engine. Other 45 Compressor 22 includes a plurality of compressor stages embodiments include apparatuses, systems, devices, hard- (not shown), and is coupled to HP turbine 26 via HP shaft 28 ware, methods, and combinations for gas turbine engine in a driving arrangement. Compressor 22 is configured to systems and exhaust nozzle systems for gas turbine engines.

pressurize the airflow received at its inlet from adaptive fan Further embodiments,forms, features, aspects, benefits, and 50 16. Some of the compressor discharge air and/or interstage advantages of the present application will become apparent air pressurized by compressor 22 may be supplied to other from the description and figures provided herewith.

engine 10 components, e.g., turbine wheels, blades and BRIEF DESCRIPTION OF THE DRAWINGS vanes, for cooling. In addition, some of the compressor discharge air and/or interstage air pressurized by compressor The description herein makes reference to the accompa- 55 22 may be provided in the form of customer bleed air, e.g., nying drawings wherein like reference numerals refer to like for use by the aircraft environmental control systems, as well parts throughout the several views, and wherein: as for use in active lift surfaces and control surfaces of the FIG. 1 schematically depicts some aspects of a non- aircraft, e.g., to maintain desirable airflow characteristics of limiting example of a variable cycle aircraft gas turbine such surfaces under varying flight conditions.

engine in accordance with an embodiment of the present 60 Combustor 24 is in fluid communication with compressor invention. 22, and is structured to combust a mixture of fuel and FIG. 2 is a sectional view illustrating some aspects of a compressor discharge air received from compressor 22. HP non-limiting example of a supersonic converging-diverging turbine 26 is in fluid communication with combustor 24, and nozzle in accordance with an embodiment of the present is operative to receive the hot gases discharged by combus- invention. 65 tor 24, and to extract power therefrom for driving compres- FIG. 3 is a partial isometric sectional view illustrating sor 22. Engine core flowpath gases exiting HP turbine 26 are some aspects of a non-limiting example of a supersonic directed into LP turbine 14, which extracts mechanical

US 9,714,608 B2

_►, power from the hot working airflow to drive adaptive fan 16. a second stream flow. The air flow discharged by fan 30 into LP shaft 18 is coupled to LP turbine 14, and is configured to bypass duct 34 is also a bypass flow, and is referred to herein receive and transmit the mechanical power from LP turbine as a third stream flow. That is, in the embodiment depicted 14 to adaptive fan 16. in FIG. 1, engine 10 discharges into exhaust nozzle system Adaptive fan 16 includes a base fan 30 and a variable- 5 20 three distinct flow streams: the first stream flow, second speed fan 32, both of which are powered by LP turbine 14 stream flow and third stream flow mentioned above. In other via LP shaft 18. It will be noted that in other embodiments embodiments, engine 10 may only discharge two flow of the present invention, depending on the configuration streams into exhaust nozzle system 20, e.g., a core flow and and/or installation of engine 10, another base rotating load a single bypass flow, or may discharge into exhaust nozzle in addition to or in place of base fan stage 30 may be io system 20 any number of flow streams.

employed, and another variable-speed rotating load in addi- Under some operating conditions, for example, low air- tion to or in place of variable-speed fan stage 32 may be craft speed subsonic operating conditions, such as take-off, employed. Examples of other base rotating loads include, approach, cut-back, landing and/or other low speed near- but are not limited to, generators, pumps, gearboxes and ground or on-ground operations, it is desirable to reduce the compressors, the latter including one or more engine 10 core 15 noise generated by engine 10. One way of reducing noise and/or intermediate compressors and/or engine 10 driven during such operations is to reduce the velocity or the equipment. Examples of other variable-speed rotating loads exhaust stream discharged by exhaust nozzle system 20. In include, but are not limited to, generators, pumps, gear- one form, exhaust nozzle system 20 includes an ejector to boxes, one or more boost compressors, and/or may be one or entrain ambient free stream air (i.e., air from outside of more stages of a core and/or intermediate compressor, e.g., 20 engine 10, e.g., air inside or outside of the nacelle, housing powered by HP shaft 28 and/or another turbine via a or other structure into which engine 10 is installed) into the transmission system, such as that described herein, which is first stream flow, second stream flow and/or third stream configured to vary the speed of the variable-speed rotating flow in order to reduce the velocity of the exhaust stream load. discharged by exhaust nozzle system 20.

In one form, base fan 30 includes a single rotating fan 25 Referring now to FIGS. 2 and 3, some aspects of a stage. In other embodiments, base fan 30 may include more non-limiting example of exhaust nozzle system 20 in accor- than one fan stage. In one form, variable-speed fan 32 dance with an embodiment of the present invention are includes one rotating fan stage. In other embodiments, illustrated. The illustrations of FIGS.2 and 3 are sectional in variable-speed fan 32 may include more than one rotating nature, and only illustrate a portion of many of the compo- fan stage. so nents identified herein, e.g., approximately 90 degrees of It will be understood that the term, "variable-speed," as rotation for circular or elliptical components. It will be applied to variable-speed fan 32, does not imply that the understood by those of ordinary skill in the art that an actual base rotating load, which in the present embodiment base an nozzle system 20 would extend to 360 degrees of fan 30, is limited to rotation at a single speed. Rather, the rotation.

term,"variable-speed" is meant to indicate that the variable- 35 In one form, exhaust nozzle system 20 is a supersonic speed load, which in the present embodiment is variable- converging-diverging nozzle. In other embodiments, speed fan 32, has a speed that is variable, in particular, exhaust nozzle system 20 may not be a supersonic converg- variable relative to the speed of the base rotating load, e.g., ing-diverging nozzle. Exhaust nozzle system 20 includes a base fan 30. mixer 50, a nozzle 54, a nozzle 58, an inner flowpath 62, a Aportion ofthe airflow exiting base fan 30 is directed into 40 middle flowpath 66, an outer flowpath 70, an ejector 74 and a bypass duct 34 for directly providing thrust via exhaust an ejector 78. In one form, exhaust nozzle system 20 is nozzle system 20, and the balance is directed to variable- configured to discharge the third stream flow with entrained speed fan 32. A portion of the airflow exiting variable-speed ambient free stream air, and mixed first stream flow and fan 32 is directed into a bypass duct 36 for directly providing second stream flow. In other embodiments, exhaust nozzle thrust via exhaust nozzle system 20, and the balance is 45 system 20 may be configure to discharge only two flow directed into compressor 22 as core airflow, which provides streams with or without entrained ambient free steam air, or thrust via exhaust nozzle system 20 after exiting LP turbine any other number offlow streams with or without entrained 14. ambient free steam air.

In one form, adaptive fan 16 is powered by LP turbine 14 Mixer 50 is configured to mix the first stream flow and the via LP shaft 18, as previously mentioned. In one form, base 50 second stream flow. Mixer 50 is positioned upstream of fan 30 is coupled directly to LP shaft 18 and driven thereby, nozzle 54. In other embodiments, mixer 50 may be config- whereas variable-speed fan 32 is coupled to LP shaft 18 via ured to mix other flow streams. In one form, mixer 50 is a an intervening transmission system 38, and hence is pow- forced mixer. In other embodiments, mixer 50 may not be a ered indirectly by LP shaft 18 via transmission system 38. In forced mixer. For example and without limitation, in various the present embodiment, transmission system 38 is config- 55 embodiments, mixer 50 may be a chevron mixer or a simple ured to selectively vary the speed of variable-speed fan 32, splitter that allows the first stream flow and the second e.g., relative to the speed of base fan 30. In other embodi- stream flow to mix, e.g., confluent flow mixing. In one form, ments, fan 32 may not be powered by a transmission, e.g., mixer 50 is a lobed mixer. In other embodiments, mixer 50 transmission system 38, but rather, may be powered directly may take other forms. In one form, mixer 50 is fixed. In by LP shaft 18 or HP shaft 28. In still other embodiments, 60 other embodiments, mixer 50 may be a variable mixer, e.g., fan 16 may be a conventional fan having one or more stages moveable between different positions and configured to vary operating at the same speed. the mixing length and/or the bypass ratio as between the The gas flow discharged by LP turbine 14 is an engine second stream flow and the first stream flow and/or between core flow, and is referred to herein as a first stream flow. The other flow streams. Still other embodiments may not employ first stream flow is discharged from LP turbine 14 around an 65 a mixer.

engine tailcone 40. The air flow discharged by fan 32 into In one form, nozzle 54 is positioned downstream of mixer bypass duct 36 is a bypass flow, and is referred to herein as 50. In other embodiments, nozzle 54 may be positioned

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upstream of mixer 50.In one form, nozzle 54 is a converging doors 98 are configured to vary the amount of ambient free nozzle configured to accelerate and discharge the mixed first stream air entrained into the other flow stream, e.g., by changing positions.

stream flow and second stream flow. The length of nozzle 54 In one form, each ejector door 98 is pivotably attached to may vary with the needs of the application, e.g., to achieve 5 side wall 82 (and/or one or more other structures in other a desired exhaust plume shape. In one form, nozzle 54 has embodiments), and is configured to pivot about a pivot point a circular throat. In other embodiments, the throat of nozzle 102 in order to vary its position. In other embodiments, 54 may be another shape, e.g., elliptical, rectangular or any ejector doors 98 may be configured for other forms of other suitable shape.

motion, e.g., translation, alone or in combination with rota- Nozzle 58 is disposed downstream of nozzle 54. Nozzle io tion. Ejector doors 98 are configured to selectively form and 58 is configured to receive, accelerate and discharge the vary a gap between nozzle exterior wall 94 (and/or other mixed first stream flow and second stream flow. In one form, structures in other embodiments) and ejector doors 98. By nozzle 58 is a variable nozzle. In other embodiments, nozzle varying the position of ejector doors 98, ejector doors 98 are 58 may be a fixed nozzle. In one form, nozzle 58 is configured to selectively vary the gap between nozzle exte- configured as a diverging nozzle. In other embodiments, 15 rior wall 94 (and/or other structures in other embodiments) nozzle 58 may be configured as a converging nozzle, or as and ejector doors 98, and hence vary the amount of ambient a nozzle operative to selectively function as a converging air entrained into the third flow stream (or one or more other nozzle and a diverging nozzle.In some embodiments, nozzle flow streams in other embodiments). The size of the gap at 58 may be a converging diverging nozzle. In a particular a particular angle of ejector doors 98 may vary with the form, nozzle 58 is configured as a variable diverging nozzle 20 needs ofthe application. In one example, approximately 10° having a variable divergence angle. In one form, nozzle 58 or less ofrotation ofejector doors 98 has been found suitable is formed of a two flaps 84 positioned opposite each other. for entraining a sufficient amount of ambient air at take-off conditions and other near-ground operations to meet desired In other embodiments, any number of flaps or other struc- noise reduction goals. The amount ofrotation may vary with tures may be employed. In still other embodiments, nozzle 25 the needs of the application. In some embodiments, ejector 58 may take other forms. In one form,flaps 84 are pivotably doors 98 may be selectively rotated a larger amount, e.g., attached to a side wall 82, e.g., of an engine nacelle, and are 30-60 degrees, in order to form a thrust reverser. In other each configured to pivot about a pivot point 86 in order to embodiments, ejector doors 98 may be rotated or otherwise vary the divergence angle of nozzle 58. In one form,flaps 84 moved to greater or lesser degrees in order to form a thrust are arcuate. In other embodiments, flaps 84 may be linear, 30 reverser.

e.g., flat. In various embodiments, flaps 84 may take any In one form, ejector doors 98 are also configured to suitable shape. In one form,flaps 84 are configured to rotate selectively prevent the entrainment of the ambient free to approximately 0° divergence angle for use during low stream air. In other embodiments, ejector doors 98 may not speed operations, and to approximately 10° divergence be configured to selectively prevent the entrainment of the angle for high sonic, transonic and supersonic flight opera- 35 ambient free stream air. In one form, ejector doors 98 are tions. In other embodiments, other angles may be employed.

configured to selectively prevent the entrainment of the In still other embodiments, flaps 84 may be configured for ambient free stream air by moving into a position that closes other forms of motion, e.g., translation, alone or in combi- the gap between nozzle exterior wall 94 (and/or other nation with rotation, in order to vary the divergence angle.

structures in other embodiments) and ejector doors 98. In Inner flowpath 62 is in fluid communication with the 40 other embodiments, ejector doors 98 may be configured to discharge of LP turbine 14, and is operative to receive and selectively prevent the entrainment of the ambient free conduct the pressurized gases discharged by LP turbine 14 stream air via other means.

(first stream flow). Inner flowpath 62 is formed between In addition, in some embodiments, ejector doors 98 are tailcone 40 and mixer 50. Middle flowpath 66 is in fluid configured to form a nozzle 106 in addition to forming an communication with bypass duct 36, and is operative to 45 ejector. For example, in the depiction of FIG. 2, a counter- receive and conduct pressurized air discharged by fan 32 clockwise rotation of the depicted ejector door 98 would (second stream flow). Middle flowpath 66 is formed eventually result in closing the gap between ejector door 98 between mixer 50 and a wall 90 extending from nozzle 54. and wall 94; in some embodiments, ejector doors 98 are Outer flowpath 70 is in fluid communication with bypass configured to form a diverging nozzle when in the closed duct 34, and is operative to receive and conduct pressurized 50 position. Rotation in the clockwise direction of the depicted air discharged by fan 30 (third stream flow). Outer flowpath ejector door 98 would result in a reduction in the divergence 70 is formed between wall 90 and a nozzle exterior wall 94. angle, and continued rotation in the clockwise direction Ejector 74 is configured to entrain ambient free stream air would yield ejector door 98 to be at a converging angle, into the third flow stream received via outer flowpath 70 to hence forming,in conjunction with the other ejector door 98, form a mixed flow including both the ambientfree stream air 55 a converging nozzle. Thus, at low speed operation, wherein and the third stream flow. In some embodiments, ejector 74 it is desirable to entrain ambient free stream air in order to is also configured to form a thrust reverser. In other embodi- reduce noise, ejector doors 98 also form a converging nozzle ments, ejector 74 may not form a thrust reverser. In one in some embodiments. At high speed operation, ejector form, ejector 74 includes two ejector doors 98. In other doors 98 would be rotated in the opposite direction to form embodiments, ejector 74 may take other forms and/or may 6o a diverging nozzle, and reducing or eliminating the entrain- include any number of ejector doors. In one form, ejector ment of ambient free stream air. Hence, in some embodi- doors 98 are arcuate. In other embodiments, ejector doors ments, ejector doors 98 are configured to selectively form may be linear, e.g., flat. In various embodiments, ejector nozzle 106 as a converging or a diverging nozzle. In one doors 98 may take any suitable shape. In one form, ejector form, nozzle 106 is formed in part by the shape of the doors 98 are variable-position doors, e.g., doors that are 65 exterior surfaces of nozzle 58, in conjunction with the configured to be moved by one or more actuation systems interior surfaces of ejector doors 98. In other embodiments, (not shown)into more than one position. In one form,ejector nozzle 106 may be formed by ejector doors 98 alone.

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In one form, ejector 78 is disposed inward of ejector 74, In still another additional refinement, the variable nozzle and is configured to entrain air from the mixed flow in outer is configured as a variable diverging nozzle having a vari- flowpath 70 into the flow stream discharged by the nozzle able divergence angle.

54. In other embodiments, ejector 78 may be configured to In yet still another additional refinement, the first nozzle entrain air from the third stream flow in flowpath 70, e.g., 5 is a converging nozzle.

upstream of ejector 74, or to entrain air from one or more Embodiments of the present invention include an exhaust other sources. In one form, ejector 78 is formed by nozzle nozzle system for a gas turbine engine, comprising: 58, by changing its position (the positions of flaps 84) to a first nozzle configured to discharge a flow stream of the form a gap between nozzle 58 and nozzle 54, e.g., the aft gas turbine engine, wherein the first nozzle is a converging surface of nozzle 54. In other embodiments, ejector 78 may io nozzle; and be formed by other structures. In one form, ejector 78 is a a first ejector in fluid communication with an other flow variable ejector configured to vary the amount of air stream discharged by the gas turbine engine and configured entrained into the flow stream discharged by nozzle 54, e.g., to entrain ambient free stream air into the other flow stream by varying the position of flaps 84 to vary the gap between to form a mixed flow, wherein the first ejector is also flaps 84 and nozzle 54. In other embodiments, ejector 78 15 configured to form a thrust reverser.

may not be a variable ejector. In one form, ejector 78 is In a refinement, the first ejector includes a plurality of configured to selectively close and prevent entrainment of variable-position ejector doors.

air from the mixed flow or third stream flow, e.g., by In another refinement, the ejector doors are configured to changing the position offlaps 84 to engage the aft surface of vary an amount of ambient free stream air entrained into the nozzle 54, thereby closing the gap between nozzle 58 and 20 other flow stream.

nozzle 54. In yet another refinement, the ejector doors are configured Embodiments of the present invention include a gas to close and prevent entrainment of ambient free stream air.

turbine engine system, comprising: a fan system; a com- In still another refinement, the ejector doors are config- pressor system in fluid communication with the fan system; ured to selectively form a thrust reverser.

a combustion system in fluid communication with the com- 25 In yet still another refinement, the ejector doors are pressor system; a turbine system in fluid communication configured to form a second nozzle.

with the combustion system, wherein the turbine system is In a further refinement, the second nozzle is configured to configured to discharge a first stream flow in the form of an selectively form a converging nozzle or a diverging nozzle.

engine core flow; and wherein the fan system is configured In a yet further refinement, the wherein the flow stream is to discharge a second stream flow in the form of a bypass 30 a combination of an engine core flow and a first bypass flow flow and to discharge a third stream flow in the form of an stream, and wherein the other flow stream is a second bypass other bypass flow; and a exhaust nozzle system in fluid flow stream different from the first bypass flow stream.

communication with the fan system and the turbine system, In a still further refinement, the exhaust nozzle system including: a first nozzle configured to discharge the first further comprises a third nozzle configured to discharge the stream flow and the second stream flow; and an ejector 35 flow stream.

configured to entrain ambient free stream air into the third In a yet still further refinement, the third nozzle is a stream flow. diverging nozzle.

In a refinement, the exhaust nozzle system is configured In an additional refinement, the third nozzle is configured to discharge the third stream flow with entrained ambient as a variable nozzle.

free stream air, and the first stream flow and the second 40 In another additional refinement, the variable nozzle is stream flow. configured as a variable divergent nozzle having a variable In another refinement, the exhaust nozzle system includes divergence angle.

a mixer configured to mix the first stream flow and the In yet another additional refinement, the exhaust nozzle second stream flow. system further comprises a second ejector disposed inward In yet another refinement, the ejector includes a plurality 45 of the first ejector, wherein the second ejector is configured of ejector doors. to entrain air from the mixed flow or the other flow stream In still another refinement, the ejector doors are variable- into the flow stream discharged by the first nozzle.

position doors. In still another additional refinement, the second ejector is In yet still another refinement, the ejector doors are formed by a third nozzle, wherein the third nozzle is configured to vary an amount of ambient free stream air 50 disposed downstream of the first nozzle.

entrained into the third stream flow. In yet still another additional refinement, the second In a further refinement,the ejector doors are configured to ejector is configured as a variable ejector.

close and prevent entrainment of ambient free stream air. In the second ejector is also configured to close and In a yet further refinement, the ejector doors are config- prevent entrainment of the air from the mixed flow or the ured to selectively form a thrust reverser. 55 other flow stream.

In a still further refinement, the ejector doors are config- In another refinement, the first nozzle is a converging ured to form a second nozzle. nozzle.

In a yet still further refinement, the second nozzle is In yet another refinement, the flow stream is a combina- configured to selectively form a converging nozzle or a tion of an engine core flow and a first bypass flow stream, diverging nozzle. 60 further comprising a mixer disposed upstream of the first In an additional refinement, the exhaust nozzle system is nozzle and configured to mix the engine core flow and the configured as a supersonic nozzle system. first bypass flow stream.

In another additional refinement, the exhaust nozzle sys- Embodiments of the present invention include a gas tem includes a third nozzle configured to discharge the first turbine engine system, comprising: a fan system; a com- stream flow and the second stream flow. 65 pressor system in fluid communication with the fan system; In yet another additional refinement, the third nozzle is a combustion system in fluid communication with the com- configured as a variable nozzle. pressor system; a turbine system in fluid communication

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with the combustion system, wherein the turbine system is 4. The gas turbine engine system of claim 1, wherein the configured to discharge a first stream flow in the form of an ejector doors are configured to form a second nozzle that engine core flow; and wherein the fan system is configured provides a converging nozzle or a diverging nozzle.

to discharge a second stream flow in the form of a bypass 5. The gas turbine engine system of claim 1, wherein the flow and to discharge a third stream flow in the form of an 5 exhaust nozzle system includes a second nozzle configured other bypass flow; and an exhaust nozzle system in fluid to discharge the first stream flow and the second stream flow.

communication with the fan system and the turbine system, 6. The gas turbine engine system of claim 5, wherein the including: means for discharging the first stream flow, the second nozzle is configured as a variable nozzle.

second stream flow and the third stream flow, including 7. The gas turbine engine system of claim 6, wherein the means for reversing thrust of the gas turbine engine system. io variable nozzle is configured as a variable diverging nozzle While the invention has been described in connection having a variable divergence angle.

with what is presently considered to be the most practical 8. The gas turbine engine system of claim 1, wherein the and preferred embodiment, it is to be understood that the first nozzle is a converging nozzle.

invention is not to be limited to the disclosed embodiment 9. The gas turbine engine system of claim 1, further (s), but on the contrary, is intended to cover various modi- 15 comprising a second ejector configured to entrain air into the fications and equivalent arrangements included within the flow stream discharged by the first nozzle, the second ejector spirit and scope of the appended claims, which scope is to including a plurality of ejector doors extending from for- be accorded the broadest interpretation so as to encompass ward ends to aft ends located aft of the forward ends, the all such modifications and equivalent structures as permitted ejector doors of the second ejector pivotably mounted for under the law. Furthermore it should be understood that 20 rotation about points closer to the aft ends of the ejector while the use ofthe word preferable, preferably, or preferred doors included in the second ejector than the forward ends in the description above indicates that feature so described of the ejector doors included in the second ejector.

may be more desirable, it nonetheless may not be necessary 10. An exhaust nozzle system for a gas turbine engine, and any embodiment lacking the same may be contemplated comprising: as within the scope ofthe invention, that scope being defined 25 a first nozzle configured to discharge a flow stream of the by the claims that follow. In reading the claims it is intended gas turbine engine, wherein the first nozzle is a con- that when words such as "a," "an," "at least one" and "at verging nozzle; least a portion" are used, there is no intention to limit the a first ejector in fluid communication with another flow claim to only one item unless specifically stated to the stream discharged by the gas turbine engine and con- contrary in the claim. Further, when the language "at least a 30 figured to entrain ambient free stream air into the portion" and/or "a portion" is used the item may include a another flow stream to form a mixed flow; and portion and/or the entire item unless specifically stated to the a second ejector disposed inward of the first ejector, contrary. wherein the second ejector is configured to entrain air What is claimed is: from the mixed flow or the another flow stream into the 1. A gas turbine engine system, comprising: 35 flow stream discharged by the first nozzle, wherein the a fan system; second ejector is formed by a plurality of variable- a compressor system in fluid communication with the fan position flaps extending from forward ends to aft ends system; located aft ofthe forward ends, and wherein each ofthe a combustion system in fluid communication with the plurality of variable-position flaps is pivotably compressor system; 40 mounted for rotation about points located closer to the a turbine system in fluid communication with the com- aft end of the variable-position flap than the forward bustion system, wherein the turbine system is config- end of the variable position flap.

ured to discharge a first stream flow in the form of an 11. The exhaust nozzle system of claim 10, wherein the engine core flow; first ejector includes a plurality of variable-position ejector and wherein the fan system is configured to discharge a 45 doors.

second stream flow in the form of a bypass flow and to 12. The exhaust nozzle system of claim 11, wherein the discharge a third stream flow in the form of another bypass ejector doors are configured to vary an amount of the flow; and ambient free stream air entrained into the another flow an exhaust nozzle system in fluid communication with the stream.

fan system and the turbine system, including: 50 13. The exhaust nozzle system of claim 12, wherein the a first nozzle configured to discharge the first stream flow ejector doors are configured to selectively close and prevent and the second stream flow; entrainment of the ambient free stream air.

an ejector configured to entrain ambient free stream air 14. The exhaust nozzle system of claim 11, wherein the into the third stream flow, the ejector including a ejector doors are configured to form a second nozzle that plurality of ejector doors extending from forward ends 55 provides a converging nozzle or a diverging nozzle.

to aft ends located aft of the forward ends, the ejector 15. The exhaust nozzle system of claim 10, wherein the doors pivotably mounted for rotation about points second ejector is formed by a second nozzle, wherein the closer to the aft ends of the ejector doors than the second nozzle is disposed downstream of the first nozzle.

forward ends of the ejector doors; and 16. The exhaust nozzle system of claim 10, wherein the a lobed mixer configured to mix the first stream flow and 60 first ejector is configured to entrain ambient free stream air the second stream flow. into the third stream flow, the first ejector including a 2. The gas turbine engine system of claim 1, wherein the plurality of ejector doors extending from forward ends to aft ejector doors are configured to vary an amount of the ends located aft of the forward ends, the ejector doors ofthe ambient free stream air entrained into the third stream flow. first ejector pivotably mounted for rotation about points 3. The gas turbine engine system of claim 2, wherein the 65 closer to the aft ends ofthe ejector doors included in the first ejector doors are configured to selectively close and prevent ejector than the forward ends of the ejector doors included entrainment of the ambient free stream air. in the first ejector.

US 9,714,608 B2

11 12

17. An exhaust nozzle system for a gas turbine engine, comprising: a first nozzle configured to discharge a flow stream of the gas turbine engine, wherein the first nozzle is a fixed- position nozzle that converges toward a central axis at s an aft end of the first nozzle and the flow stream is a combination of an engine core flow and a first bypass flow stream; a first ejector in fluid communication with another flow stream discharged by the gas turbine engine and con- io figured to entrain ambient free stream air into the another flow stream to form a mixed flow; and a mixer disposed upstream of the first nozzle and config- ured to mix the engine core flow and the first bypass flow stream. 15