Low noise aeroengine inlet system

Abstract

An aeroengine is provided with a splitter apparatus disposed in a section of an inlet duct. The splitter apparatus can be actuated from a stowed position to a deployed position to allow splitter(s) to selectively move from out of the inlet flow to a position extending into the inlet duct to divide the inlet flow into multiple passages.

1 . A compressor inlet system for an aeroengine, the compressor inlet system comprising an inlet duct for directing an air flow to a compressor of the aeroengine, and an inlet splitter moveable between a stowed position in which the splitter is disposed substantially out of the air flow so that the inlet duct provides substantially only one passage to the compressor, and a deployed position in which the splitter is disposed in the inlet duct to divide the inlet duct into at least two passages to the compressor, and wherein at least one surface of the splitter exposed to the air flow includes an acoustic treatment configured to reduce aeroengine noise, the splitter acoustic treatment is tuned substantially for attenuating a first noise frequency and an inner surface of the inlet duct comprises at least one acoustic treatment area tuned substantially for attenuating a second noise frequency different from the first noise frequency. 
     
     
         2 . The compressor inlet system as defined in  claim 1 , wherein the splitter is positioned adjacent an inner surface of a section of the inlet duct when in the stowed position. 
     
     
         3 . The compressor inlet system as defined in  claim 1 , wherein the splitter is pivotally mounted to a wall of the inlet duct about an axis substantially parallel to a direction of the air flow, the splitter being pivotally moveable between the stowed position and the deployed position. 
     
     
         4 . The compressor inlet system as defined in  claim 3 , comprising an actuator operatively connected to the splitter for actuating the pivotal motion thereof between the stowed position and the deployed position. 
     
     
         5 . The compressor inlet system as defined in  claim 3 , wherein the inlet duct comprises substantially flat and opposed first and second walls, the splitter being pivotally mounted to one of the first and second walls. 
     
     
         6 . The compressor inlet system as defined in  claim 5 , wherein the splitter comprises a substantially rectangular plate having a width from a first edge which is pivotally connected to said one of the first and second walls, to a second edge which is opposite to the first edge, substantially equal to a distance measured from the first to the second wall. 
     
     
         7 . The compressor inlet system as defined in  claim 1 , wherein the splitter comprises at least first and second splitter plates pivotally mounted to respective substantially flat and opposed first and second walls of the inlet duct about respective first and second axes substantially parallel to a direction of the air flow, the first and second splitter plates being pivoted to a position parallel to and adjacent the respective first and second walls of the inlet duct when the splitter is in the stowed position and, the first and second splitter plates being pivoted to extend from the respective first and second walls into the inlet duct and to in combination form a partition wall extending in a section of the inlet duct when the splitter apparatus is in the deployed position. 
     
     
         8 . The compressor inlet system as defined in  claim 1 , wherein the at least one acoustic treatment area of the inner surface of the inlet duct is covered by the splitter when the splitter is in the stowed position and is exposed when the splitter is in the deployed position. 
     
     
         9 . A compressor inlet system for an aeroengine, the compressor inlet system comprising an inlet duct for directing an air flow to a compressor of the aeroengine, and an inlet splitter moveable between a stowed position in which the splitter is disposed substantially out of the air flow so that the inlet duct provides substantially only one passage to the compressor, and a deployed position in which the splitter is disposed in the inlet duct to divide the inlet duct into at least two passages to the compressor, and wherein at least one surface of the splitter exposed to the air flow includes an acoustic treatment configured to reduce aeroengine noise and tuned substantially for attenuating a first noise frequency, and an inner surface of the inlet duct comprises at least one acoustic treatment area tuned substantially for attenuating a second noise frequency different from the first noise frequency, wherein the at least one acoustic treatment area of the inner surface of the inlet duct is covered by the splitter when the splitter is in the stowed position and is exposed when the splitter is in the deployed position. 
     
     
         10 . The compressor inlet system as defined in  claim 9 , wherein the splitter is positioned adjacent an inner surface of a section of the inlet duct when in the stowed position. 
     
     
         11 . The compressor inlet system as defined in  claim 9 , wherein the splitter is pivotally mounted to a wall of the inlet duct about an axis substantially parallel to a direction of the air flow, the splitter being pivotally moveable between the stowed position and the deployed position. 
     
     
         12 . The compressor inlet system as defined in  claim 11 , comprising an actuator operatively connected to the splitter for actuating the pivotal motion thereof between the stowed position and the deployed position. 
     
     
         13 . The compressor inlet system as defined in  claim 11 , wherein the inlet duct comprises substantially flat and opposed first and second walls, the splitter being pivotally mounted to one of the first and second walls. 
     
     
         14 . The compressor inlet system as defined in  claim 13 , wherein the splitter comprises a substantially rectangular plate having a width from a first edge which is pivotally connected to said one of the first and second walls, to a second edge which is opposite to the first edge, substantially equal to a distance measured from the first to the second wall. 
     
     
         15 . The compressor inlet system as defined in  claim 9 , wherein the splitter comprises at least first and second splitter plates pivotally mounted to respective substantially flat and opposed first and second walls of the inlet duct about respective first and second axes substantially parallel to a direction of the air flow, the first and second splitter plates being pivoted to a position parallel to and adjacent the respective first and second walls of the inlet duct when the splitter is in the stowed position and, the first and second splitter plates being pivoted to extend from the respective first and second walls into the inlet duct and to in combination form a partition wall extending in a section of the inlet duct when the splitter apparatus is in the deployed position.