Cooled gas turbine aerofoil

Abstract

A gas turbine engine aerofoil ( 24 ) has a plurality of attenuation chambers ( 34 ) positioned between a cooling air passageway ( 26 ) and its leading edge ( 28 ). The pressure of the cooling air passing from the passageway ( 26 ) to the exterior surface of the leading edge is attenuated by impingement on the opposing walls of the respective chambers ( 34 ), or by expansion therein, prior to leaving the chambers( 34 ), via passageways ( 38 ).

I claim:  
     
         1 . A gas turbine engine aerofoil having a root, a tip and a leading edge a cooling air passageway which extends from said root thereof to a position adjacent its tip, and a plurality of elongate chambers spaced from said passageway in a portion of said aerofoil between said leading edge and said passageway, each said chamber being connected to said passageway by cooling air input passageways and to the exterior surface of said leading edge of said aerofoil by cooling air exit passageways.  
     
     
         2 . A gas turbine engine aerofoil as claimed in  claim 1  wherein each of said chambers is generally parallel with said cooling air passageway extending from root to said position adjacent said tip.  
     
     
         3 . A gas turbine engine aerofoil as claimed in  claim 1  wherein said cooling air input and exit passageways are offset with respect to each other.  
     
     
         4 . A gas turbine engine aerofoil as claimed in preceding  claim 1  wherein each chamber is provided with a greater number of cooling air exit passageways than cooling air input passageways.  
     
     
         5 . A gas turbine engine aerofoil as claimed in preceding  claim 1  wherein said cooling air input passageways are generally parallel with said cooling air exit passageways.  
     
     
         6 . A gas turbine engine aerofoil as claimed in  claim 1  wherein said cooling air input passageways are so positioned as to be other than parallel with respect to said cooling air exit passageways.