Gas turbine engine inlet with noise reduction features
A gas turbine engine comprising a fan section, a compressor, a combustor and a turbine, includes a nacelle having an inner nacelle surface defining an inlet duct designed to reduce an inlet duct area of the inlet duct to increase acoustic attenuation. The gas turbine engine also includes a spinner, disposed forward of the fan section, that includes features to increase acoustic attenuation. In one embodiment of the present invention, the nacelle includes a nacelle contoured surface protruding radially inward from the inner nacelle surface to reduce the inlet duct area. In a further embodiment of the present invention, the spinner includes a spinner contoured surface for reducing the inlet duct area. In other embodiments, the nacelle and/or the spinner include an inflatable bladder, a SMA actuator, a fluidic actuator, or a combination thereof, selectively activated to increase acoustic attenuation during certain conditions of an aircraft.
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1. Technical Field
The present invention relates to gas turbine engines and, more particularly, to reduction of noise emanating therefrom.
2. Background Art
In recent years, noise generated by flying aircraft has attracted attention and is now subject of various governmental regulations. Efforts need to be made to minimize annoyance to neighborhoods located in the path of departing and landing aircraft. The noise is especially disturbing during certain flight conditions such as takeoffs and landings of the aircraft.
The aircraft noise is primarily generated by gas turbine engines propelling the aircraft. One major source of the noise generated by the gas turbine engine is the fan section. The fan generates tonal and broadband acoustic energy propagating outward of the engine through an inlet and through a bypass nozzle.
Various considerations dictate design of the gas turbine engine that propels an aircraft. For example, several critical concerns are thrust of the engine, fuel efficiency, cooling, and the overall weight. Frequently, optimization of one factor results in undesirable consequences for another. Therefore, design of an engine includes multiple trade-offs to obtain an optimal engine. Although noise generated by the gas turbine engine is now subject to fairly stringent governmental regulations, to date, the noise considerations were not part of the design optimization for conventional engines.
SUMMARY OF THE INVENTIONAccording to the present invention, a gas turbine engine comprises a nacelle enclosing a fan section, a compressor, a combustor and a turbine, with the nacelle including an inner nacelle surface defining an inlet duct and means for reducing an inlet duct area of the inlet duct to increase acoustic attenuation during certain conditions of an aircraft. The means for reducing the inlet area is disposed on an inner nacelle surface or on a spinner, disposed forward of the fan section, or on both, the inner nacelle surface and the spinner surface.
In one embodiment of the present invention, the means for reducing the inlet area includes a nacelle contoured surface protruding radially inward from the inner nacelle surface to reduce the inlet duct area. In another embodiment of the present invention, the means for reducing the inlet area includes a spinner contoured surface protruding into the inlet duct to reduce the inlet duct area. In yet another embodiment, the means for reducing the inlet area comprises means for selectively reducing the inlet area. In a further embodiments, the means for selectively reducing the inlet area comprises an inflatable bladder, a SMA actuator, a fluidic actuator, or a combination thereof. The inflatable bladder, the SMA actuator, and the fluidic actuator are disposed on an inner nacelle surface or on a spinner, or on both, the inner nacelle surface and the spinner surface. The means for selectively reducing the inlet area may be also used in combination with the nacelle and/or spinner contoured surfaces.
The foregoing and other advantages of the present invention become more apparent in light of the following detailed description of the exemplary embodiments thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
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The fan 26 of the engine 10 includes a plurality of fan blades 46 and a spinner 48 disposed forward of the fan 26. Each fan blade 46 comprises an airfoil-shaped portion 50 that spans radially from a root 52 to a tip 54 and extends from a leading edge 58 to a trailing edge 60. The root of each fan blade is inserted into a hub 62. The engine 10 of
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In operation, for embodiments described above and shown in
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One major advantage of the present invention is that it addresses reduction of noise emanating from a gas turbine engine. Thus, either permanent or selective reduction of noise in a gas turbine engine renders the engine in compliance with new and more stringent regulations promulgated by various authorities. Although embodiments showing permanent changes to the contour of the inner nacelle surface and/or the spinner, such as shown in
While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention. For example, any combination of means for reducing the inlet area 64 can be used. More specifically, the means for selectively reducing the inlet area 66 such as the inflatable bladder, the SMA actuator and the fluidic actuator, can be used either alone on the inner nacelle surface and/or on the spinner surface, or in combination with either or both, the nacelle contoured surface and/or the spinner contoured surface.
Claims
1. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct; and
- means for reducing an inlet duct area of the inlet duct to increase acoustic attenuation.
2. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area is disposed forward of the fan section.
3. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area is disposed on the inner nacelle surface.
4. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area includes a nacelle contoured surface protruding radially inward from the inner nacelle surface to reduce the inlet duct area.
5. The gas turbine engine according to claim 4 wherein the nacelle contoured surface defines a throat.
6. The gas turbine engine according to claim 4 wherein the nacelle contoured surface reduces the inlet duct area to increase Mach number of incoming air.
7. The gas turbine engine according to claim 4 further comprising means for selectively reducing the inlet area disposed on the nacelle contoured surface.
8. The gas turbine engine according to claim 7 wherein the means for selectively reducing the inlet area comprises an inflatable bladder.
9. The gas turbine engine according to claim 7 wherein the means for selectively reducing the inlet area comprises an SMA actuator.
10. The gas turbine engine according to claim 7 wherein the means for selectively reducing the inlet area comprises a fluidic actuator.
11. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area includes a spinner contoured surface formed on a spinner disposed forward of the fan section.
12. The gas turbine engine according to claim 11 wherein the spinner contoured surface is a substantially blunt surface protruding forward farther than a conventional spinner surface.
13. The gas turbine engine according to claim 11 wherein the spinner contoured surface extends into a hub of a fan disposed within the fan section of the engine.
14. The gas turbine engine according to claim 11 further comprising means for selectively reducing the inlet area disposed on the spinner contoured surface.
15. The gas turbine engine according to claim 14 wherein the means for selectively reducing the inlet area comprises an inflatable bladder.
16. The gas turbine engine according to claim 14 wherein the means for selectively reducing the inlet area comprises an SMA actuator.
17. The gas turbine engine according to claim 14 wherein the means for selectively reducing the inlet area comprises a fluidic actuator.
18. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area includes a nacelle contoured surface formed on the inner nacelle surface and a spinner contoured surface formed on a spinner disposed forward of the fan section.
19. The gas turbine engine according to claim 18 wherein the nacelle contoured surface and the spinner contoured surface reduce the inlet area to increase Mach number of incoming air.
20. The gas turbine engine according to claim 18 further comprising means for selectively reducing the inlet area disposed on the nacelle contoured surface and on the spinner contoured surface.
21. The gas turbine engine according to claim 20 wherein the means for selectively reducing the inlet area comprises an inflatable bladder.
22. The gas turbine engine according to claim 20 wherein the means for selectively reducing the inlet area comprises an SMA actuator.
23. The gas turbine engine according to claim 20 wherein the means for selectively reducing the inlet area comprises a fluidic actuator.
24. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area is asymmetrical.
25. The gas turbine engine according to claim 24 wherein the means for reducing the inlet area is asymmetrical such that a lower portion of the nacelle includes a contour that protrudes a greater amount than the contour at an upper portion of the nacelle.
26. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area includes means for selectively reducing the inlet area.
27. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area has a distended position and a retracted position.
28. The gas turbine engine according to claim 27 wherein the means for selectively reducing the inlet area in the distended position protrudes radially inward into the inlet duct area to reduce the inlet duct area thereby increasing Mach number of air incoming into the gas turbine engine.
29. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is selectively activated.
30. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is activated during a takeoff condition.
31. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is activated during a flyover condition.
32. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is activated during takeoff and flyover conditions.
33. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is asymmetrical.
34. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is asymmetrical such that a lower portion of the nacelle includes a contour that protrudes a greater amount than the contour at an upper portion of the nacelle.
35. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is disposed on an inner nacelle surface of the nacelle.
36. The gas turbine engine according to claim 35 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface.
37. The gas turbine engine according to claim 36 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area and the means for selectively reducing the inlet area protrudes further inward to further reduce the inlet duct area during activated condition.
38. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is disposed on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
39. The gas turbine engine according to claim 38 wherein the spinner surface includes a spinner contoured surface.
40. The gas turbine engine according to claim 39 wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area and the means for selectively reducing the inlet area protrudes further to further reduce the inlet duct area during activated condition.
41. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area is disposed on an inner nacelle surface of the nacelle and on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
42. The gas turbine engine according to claim 41 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface and wherein the spinner surface includes a spinner contoured surface.
43. The gas turbine engine according to claim 42 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area; wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area; and wherein the means for selectively reducing the inlet area protrudes further to further reduce the inlet duct area during activated condition.
44. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area comprises an inflatable bladder.
45. The gas turbine engine according to claim 44 wherein the inflatable bladder is disposed on an inner nacelle surface of the nacelle.
46. The gas turbine engine according to claim 45 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface.
47. The gas turbine engine according to claim 46 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area and the inflatable bladder protrudes further inward to further reduce the inlet duct area during deployed condition.
48. The gas turbine engine according to claim 44 wherein the inflatable bladder is disposed on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
49. The gas turbine engine according to claim 48 wherein the spinner surface includes a spinner contoured surface.
50. The gas turbine engine according to claim 49 wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area and the inflatable bladder protrudes further to further reduce the inlet duct area during activated condition.
51. The gas turbine engine according to claim 44 wherein the inflatable bladder is disposed on an inner nacelle surface of the nacelle and on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
52. The gas turbine engine according to claim 51 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface and wherein the spinner surface includes a spinner contoured surface.
53. The gas turbine engine according to claim 52 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area; wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area; and wherein the inflatable bladder protrudes further to further reduce the inlet duct area during deployed condition.
54. The gas turbine engine according to claim 44 wherein the inflatable bladder comprises:
- a bladder;
- a plenum; and
- means to inflate the plenum.
55. The gas turbine engine according to claim 54 wherein the means to inflate the plenum includes an inlet for allowing pressurized air to enter the plenum.
56. The gas turbine engine according to claim 54 further comprising:
- means to deflate the plenum.
57. The gas turbine engine according to claim 44 wherein the inflatable bladder is asymmetrical with respect to circumference of the nacelle.
58. The gas turbine engine according to claim 57 wherein the inflatable bladder is asymmetrical such that the inflatable bladder disposed in a lower portion of the nacelle protrudes a greater amount than the inflatable bladder disposed at an upper portion of the nacelle when the inflatable bladder is in deployed position.
59. The gas turbine engine according to claim 44 wherein the inflatable bladder is segmented around the circumference of the nacelle to allow asymmetrical deployment thereof.
60. The gas turbine engine according to claim 44 wherein the inflatable bladder has a distended position and a retracted position.
61. The gas turbine engine according to claim 60 wherein the inflatable bladder in the distended position protrudes radially inward into the inlet duct area to reduce the inlet duct area thereby increasing Mach number of air incoming into the gas turbine engine.
62. The gas turbine engine according to claim 26 wherein the means for selectively reducing the inlet area comprises an SMA actuator.
63. The gas turbine engine according to claim 62 wherein the SMA actuator is asymmetrical with respect to circumference of the nacelle.
64. The gas turbine engine according to claim 63 wherein the SMA actuator is asymmetrical such that the SMA actuator disposed in a lower portion of the nacelle protrudes a greater amount than the SMA actuator disposed at an upper portion of the nacelle when the SMA actuator is in deployed position.
65. The gas turbine engine according to claim 62 wherein the SMA actuator is segmented around the circumference of the nacelle to allow asymmetrical deployment thereof.
66. The gas turbine engine according to claim 62 wherein the SMA actuator has a distended position and a retracted position.
67. The gas turbine engine according to claim 66 wherein the SMA actuator in the distended position protrudes radially inward into the inlet duct area to reduce the inlet duct area thereby increasing Mach number of air incoming into the gas turbine engine.
68. The gas turbine engine according to claim 62 wherein the SMA actuator is disposed on an inner nacelle surface of the nacelle.
69. The gas turbine engine according to claim 68 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface.
70. The gas turbine engine according to claim 69 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area and the SMA actuator protrudes further inward to further reduce the inlet duct area during deployed condition.
71. The gas turbine engine according to claim 62 wherein the SMA actuator is disposed on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
72. The gas turbine engine according to claim 71 wherein the spinner surface includes a spinner contoured surface.
73. The gas turbine engine according to claim 72 wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area and the SMA actuator protrudes further to further reduce the inlet duct area during activated condition.
74. The gas turbine engine according to claim 62 wherein the SMA actuator is disposed on an inner nacelle surface of the nacelle and on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
75. The gas turbine engine according to claim 74 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface and wherein the spinner surface includes a spinner contoured surface.
76. The gas turbine engine according to claim 75 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area; wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area; and wherein the SMA actuator protrudes further to further reduce the inlet duct area during deployed condition.
77. The gas turbine engine according to claim 62 wherein the SMA actuator comprises:
- at least one SMA member having a distended position and a retracted position such that in the distended position the at least one SMA member protrudes radially inward into the inlet area to reduce the inlet area thereby increasing Mach number of air incoming into the gas turbine engine.
78. The gas turbine engine according to claim 77 further comprising:
- means to deactivate the SMA actuator.
79. The gas turbine engine according to claim 1 wherein the means for reducing the inlet area is a fluidic actuator.
80. The gas turbine engine according to claim 79 wherein the fluidic actuator is asymmetrical with respect to circumference of the nacelle.
81. The gas turbine engine according to claim 80 wherein the fluidic actuator is asymmetrical such that the fluidic actuator disposed in a lower portion of the nacelle interferes with the incoming flow a greater amount than the fluidic actuator disposed at an upper portion of the nacelle when the fluidic actuator is activated.
82. The gas turbine engine according to claim 79 wherein the fluidic actuator is segmented around the circumference of the nacelle to allow asymmetrical deployment thereof.
83. The gas turbine engine according to claim 79 wherein the fluidic actuator has an activated position and a deactivated position.
84. The gas turbine engine according to claim 83 wherein the fluidic actuator in the activated position generates an inward flow of air into the inlet duct area to effectively reduce the inlet duct area thereby increasing Mach number of air incoming into the gas turbine engine.
85. The gas turbine engine according to claim 79 wherein the fluidic actuator is disposed on an inner nacelle surface of the nacelle.
86. The gas turbine engine according to claim 85 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface.
87. The gas turbine engine according to claim 86 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area and the fluidic actuator generates air inward into the inlet duct to effectively further reduce the inlet duct area during activated condition of the fluidic actuator.
88. The gas turbine engine according to claim 79 wherein the fluidic actuator is disposed on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
89. The gas turbine engine according to claim 88 wherein the spinner surface includes a spinner contoured surface.
90. The gas turbine engine according to claim 89 wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area and the fluidic actuator generates air into the inlet duct to effectively further reduce the inlet duct area during activated condition of the fluidic actuator.
91. The gas turbine engine according to claim 79 wherein the fluidic actuator is disposed on an inner nacelle surface of the nacelle and on a spinner surface of a spinner wherein the spinner is disposed forward of the fan section.
92. The gas turbine engine according to claim 91 wherein the inner nacelle surface of the nacelle is contoured to form a nacelle contoured surface and wherein the spinner surface includes a spinner contoured surface.
93. The gas turbine engine according to claim 92 wherein the nacelle contoured surface protrudes radially inward from the inner nacelle surface to reduce the inlet duct area; wherein the spinner contoured surface protrudes from the spinner surface to reduce the inlet duct area; and wherein the fluidic actuator generates air into the inlet duct to effectively further reduce the inlet duct area during activated condition of the fluidic actuator.
94. The gas turbine engine according to claim 79 wherein the fluidic actuator includes means for selectively blowing air into the inlet duct to effectively reduce the inlet duct area of the nacelle.
95. The gas turbine engine according to claim 79 wherein the fluidic actuator is selectively activated to effectively reduce the inlet duct area of the nacelle.
96. The gas turbine engine according to claim 95 wherein the fluidic actuator comprises:
- an air injector for injecting air into flow path of air incoming into the gas turbine engine.
97. The gas turbine engine according to claim 95 wherein the air injector includes an opening formed within the inner nacelle surface.
98. The gas turbine engine according to claim 95 wherein the air injector is being fed pressurized air channeled from another portion of the engine.
99. A gas turbine engine comprising:
- a fan section; and
- a nacelle enclosing the gas turbine engine and forming an inlet duct forward of the fan section; and
- wherein the nacelle is designed to introduce local increases in the Mach number of air-incoming into the gas turbine engine to enhance shock wave dissipation.
100. A gas turbine engine comprising:
- a fan section;
- a nacelle enclosing the gas turbine engine and forming an inlet duct forward of the fan section; and
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle;
- wherein the nacelle and the spinner are designed to introduce local increases in the Mach number of air incoming into the gas turbine engine to enhance shock wave dissipation.
101. A gas turbine engine comprising:
- a fan section;
- a nacelle enclosing the gas turbine engine and forming an inlet duct forward of the fan section; and
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle;
- wherein the spinner is designed to introduce local increases in the Mach number of air incoming into the gas turbine engine to enhance shock wave dissipation.
102. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct, wherein the inner nacelle surface is contoured to increase acoustic attenuation.
103. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct;
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle, the spinner having a spinner surface;
- wherein the spinner surface is contoured to increase acoustic attenuation.
104. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct;
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle, the spinner having a spinner surface;
- wherein the inner nacelle surface and the spinner surface are contoured to increase acoustic attenuation.
105. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct; and
- means for selectively reducing the inlet area disposed on the inner nacelle surface to increase acoustic attenuation during certain conditions of an aircraft.
106. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct;
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle, the spinner having a spinner surface; and
- means for selectively reducing the inlet area disposed on the spinner surface to increase acoustic attenuation during certain conditions of an aircraft.
107. A gas turbine engine comprising:
- a nacelle enclosing a fan section, a compressor, a combustor and a turbine, the nacelle including an inner nacelle surface defining an inlet duct;
- a spinner disposed forward of the fan section and disposed substantially centrally with respect to the nacelle, the spinner having a spinner surface; and
- means for selectively reducing the inlet area disposed on the inner nacelle surface and on the spinner surface to increase acoustic attenuation during certain conditions of an aircraft.
Type: Application
Filed: Jun 10, 2004
Publication Date: Dec 15, 2005
Applicant: United Technologies Corporation (Hartford, CT)
Inventors: Dilip Prasad (Vernon, CT), Jinzhang Feng (Avon, CT), Jayant Sabnis (Glastonbury, CT)
Application Number: 10/865,025