Stress relieved rectilinear duct

Abstract

A duct liner includes a corner flanked by a pair of keyhole slots. An exhaust duct assembly includes an impingement liner received within a duct and a duct liner received within the impingement liner, the duct liner with a multiple of corners, each of the corners flanked by a pair of keyhole slots.

What is claimed is: 
     
         1 . A duct liner comprising:
 a corner flanked by a pair of keyhole slots.   
     
     
         2 . The duct liner as recited in  claim 1 , wherein each of said pair of keyhole slots are displaced from said corner. 
     
     
         3 . The duct liner as recited in  claim 1 , wherein each of said pair of keyhole slots extend parallel to said corner. 
     
     
         4 . The duct liner as recited in  claim 1 , wherein each of said pair of keyhole slots extend through a flange. 
     
     
         5 . The duct liner as recited in  claim 1 , wherein each of said pair of keyhole slots are linear. 
     
     
         6 . The duct liner as recited in  claim 5 , wherein each of said pair of keyhole slots includes a circular end. 
     
     
         7 . An exhaust duct assembly comprising:
 a duct;   an impingement liner received within said duct; and   a duct liner received within said impingement liner, said duct liner with a multiple of corners, each of said corners flanked by a pair of keyhole slots.   
     
     
         8 . The assembly as recited in  claim 7 , wherein each of said pair of keyhole slots are displaced from said corner. 
     
     
         9 . The assembly as recited in  claim 7 , wherein each of said pair of keyhole slots extend parallel to said corner. 
     
     
         10 . The assembly as recited in  claim 7 , wherein each of said pair of keyhole slots extend through a duct liner flange of said duct liner. 
     
     
         11 . The assembly as recited in  claim 10 , wherein said duct liner flange abuts an impingement liner flange of said impingement liner. 
     
     
         12 . The assembly as recited in  claim 11 , further comprising a gasket between said duct liner flange and said impingement liner flange. 
     
     
         13 . The assembly as recited in  claim 12 , wherein said duct liner flange abuts a bulkhead. 
     
     
         14 . The assembly as recited in  claim 13 , wherein said bulkhead is defined by a gas turbine engine. 
     
     
         15 . The assembly as recited in  claim 13 , wherein said bulkhead is defined by a Hot Acoustic Rig. 
     
     
         16 . The assembly as recited in  claim 7 , wherein each of said pair of keyhole slots includes a circular end. 
     
     
         17 . The assembly as recited in  claim 16 , wherein said circular end is displaced from each corner by 2.5 times a diameter of said circular end.