System and method for forming elongated perforations in an inner barrel section of an engine

Abstract

Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

What is claimed is: 
     
         1 . An acoustic inlet barrel of an engine, the acoustic inlet barrel comprising:
 an inner barrel configured to provide a boundary for directing airflow through the engine, the inner barrel comprising an inner face sheet separated from an outer face sheet by an acoustic core, wherein the inner face sheet comprises a plurality of elongated, non-circular perforations.   
     
     
         2 . The acoustic inlet barrel of  claim 1 , wherein each of the perforations is elongated with respect to a longitudinal axis. 
     
     
         3 . The acoustic inlet barrel of  claim 2 , wherein the longitudinal axis aligns with a flow contour line of the airflow through the engine. 
     
     
         4 . The acoustic inlet barrel of  claim 1 , wherein at least one of the perforations is shaped as an elongated slot. 
     
     
         5 . The acoustic inlet barrel of  claim 1 , wherein at least one of the perforations has a teardrop shape. 
     
     
         6 . The acoustic inlet barrel of  claim 1 , wherein at least one of the perforations has an elliptical shape. 
     
     
         7 . The acoustic inlet barrel of  claim 1 , wherein at least one of the perforations has a dogbone shape. 
     
     
         8 . A method of forming a component of an engine, the method comprising:
 sandwiching an acoustic core between an inner section and an outer section of the component; and   forming a plurality of elongated, non-circular perforations in at least a portion of the inner section.   
     
     
         9 . The method of  claim 8 , wherein the forming operation comprises using at least one robotic forming unit to elongate each of the perforations with respect to a longitudinal axis. 
     
     
         10 . The method of  claim 9 , wherein the longitudinal axis aligns with a flow contour line of the airflow through the engine. 
     
     
         11 . The method of  claim 8 , wherein the forming operation comprises forming at least one of the perforations as an elongated slot. 
     
     
         12 . The method of  claim 8 , wherein the forming operation comprises forming at least one of the perforations as one or more of a teardrop shape, an elliptical shape, or a dogbone shape. 
     
     
         13 . A forming system, comprising:
 at least one robotic forming unit including at least one end effector positioned inside a barrel section configured as a composite sandwich structure having an inner face sheet, wherein the at least one robotic forming unit is operable to form a plurality of elongated, non-circular perforations into the inner face sheet using the at least one end effector to provide a predetermined percent-open-area of the inner face sheet.   
     
     
         14 . The forming system of  claim 13 , wherein each of the perforations is elongated with respect to a longitudinal axis. 
     
     
         15 . The forming system of  claim 14 , wherein the longitudinal axis aligns with a flow contour line of airflow through an engine. 
     
     
         16 . The forming system of  claim 13 , wherein at least one of the perforations is shaped as an elongated slot. 
     
     
         17 . The forming system of  claim 13 , wherein at least one of the perforations has a teardrop shape. 
     
     
         18 . The forming system of  claim 13 , wherein at least one of the perforations has an elliptical shape. 
     
     
         19 . The forming system of  claim 13 , wherein at least one of the perforations has a dogbone shape. 
     
     
         20 . The forming system of  claim 13 , wherein the at least one robotic forming unit is configured to:
 index a pattern of perforations to one or more cell walls of a honeycomb core of the composite sandwich structure;   form the pattern of perforations in the inner face sheet such that the perforations are located at a spaced distance from the cell walls of the honeycomb core; and   form the perforations such that the percent-open-area in one section of the inner face sheet is different than the percent-open-area in another section of the inner face sheet.