Gas turbine engine inlet with noise reduction features

Abstract

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.

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.