Exhaust silencer assembly

Abstract

An exhaust silencer assembly for use with a gas turbine engine, the exhaust silencer assembly comprising an exhaust duct extension disposed downstream from an exhaust diffuser of the gas turbine engine, and an exhaust silencer disposed downstream from the exhaust duct extension. The exhaust duct extension has a length that is at least about 50% of an inner diameter of the exhaust duct extension.

1 . An exhaust silencer assembly, the exhaust silencer assembly comprising:
 an exhaust duct extension disposed downstream from an exhaust diffuser, the exhaust duct extension having a length and an inner diameter, wherein the length of the exhaust duct extension is at least about 50% of the inner diameter of the exhaust duct extension; and   an exhaust silencer disposed downstream from the exhaust duct extension.   
   
   
       2 . The exhaust silencer assembly of  claim 1 , wherein the length of the exhaust duct extension ranges from about 50% of the inner diameter of the exhaust duct extension to about 300% of the inner diameter of the exhaust duct extension. 
   
   
       3 . The exhaust silencer assembly of  claim 2 , wherein the length of the exhaust duct extension ranges from about 100% of the inner diameter of the exhaust duct extension to about 200% of the inner diameter of the exhaust duct extension. 
   
   
       4 . The exhaust silencer assembly of  claim 1 , wherein the inner diameter of the exhaust duct extension ranges from about 20 centimeters to about 66 centimeters. 
   
   
       5 . The exhaust silencer assembly of  claim 4 , wherein the inner diameter of the exhaust duct extension ranges from about 25 centimeters to about 51 centimeters. 
   
   
       6 . The exhaust silencer assembly of  claim 1 , wherein the exhaust duct extension has a first end secured to the exhaust diffuser. 
   
   
       7 . The exhaust silencer assembly of  claim 1 , wherein the gas turbine engine comprises an auxiliary power unit turbine engine. 
   
   
       8 . The exhaust silencer assembly of  claim 1 , wherein the exhaust silencer comprises an integrated exhaust silencer. 
   
   
       9 . An exhaust silencer assembly for use with an auxiliary power unit turbine engine, the exhaust silencer assembly comprising:
 an exhaust duct extension located downstream from the auxiliary power unit turbine engine for receiving combustion gases emitted from the auxiliary power unit turbine engine, the exhaust duct extension having dimensions effective for allowing the combustion gases to generate downstream noise prior to exiting the exhaust duct extension; and   an exhaust silencer located downstream from the exhaust duct extension and configured to at least partially attenuate the downstream noise of the combustion gases.   
   
   
       10 . The exhaust silencer assembly of  claim 9 , wherein the dimensions of the exhaust duct extension comprise a length of the exhaust duct extension and an inner diameter of the exhaust duct extension, the length of the exhaust duct extension being at least about 50% of the inner diameter of the exhaust duct extension. 
   
   
       11 . The exhaust silencer assembly of  claim 10 , wherein the length of the exhaust duct extension ranges from about 50% of the inner diameter of the exhaust duct extension to about 300% of the inner diameter of the exhaust duct extension. 
   
   
       12 . The exhaust silencer assembly of  claim 11 , wherein the length of the exhaust duct extension ranges from about 100% of the inner diameter of the exhaust duct extension to about 200% of the inner diameter of the exhaust duct extension. 
   
   
       13 . The exhaust silencer assembly of  claim 9 , wherein the exhaust silencer comprises an integrated exhaust silencer. 
   
   
       14 . The exhaust silencer assembly of  claim 9 , wherein the exhaust duct extension and the exhaust silencer are located in an aircraft tail section. 
   
   
       15 . An auxiliary power unit assembly comprising:
 an auxiliary power unit turbine engine having an exhaust diffuser;   an eductor disposed around at least a portion the exhaust diffuser;   an exhaust duct extension having a first end secured to the eductor and a second end, the exhaust duct extension having a length between the first end and the second end and a diameter, wherein the length of the exhaust duct extension is at least about 50% of the diameter of the exhaust duct extension; and   an exhaust silencer secured to the second end of the exhaust duct extension.   
   
   
       16 . The auxiliary power unit assembly of  claim 15 , wherein the length of the exhaust duct extension ranges from about 50% of the diameter of the exhaust duct extension to about 300% of the diameter of the exhaust duct extension. 
   
   
       17 . The auxiliary power unit assembly of  claim 16 , wherein the length of the exhaust duct extension ranges from about 100% of the diameter of the exhaust duct extension to about 200% of the diameter of the exhaust duct extension. 
   
   
       18 . The auxiliary power unit assembly of  claim 15 , further comprising an exhaust pipe secured to the exhaust silencer at a location downstream from the exhaust silencer. 
   
   
       19 . The auxiliary power unit assembly of  claim 15 , wherein the exhaust silencer comprises an integrated exhaust silencer. 
   
   
       20 . The exhaust silencer assembly of  claim 15 , wherein the exhaust duct extension and the exhaust silencer are located in an aircraft tail section.