Gas turbine engine component

Abstract

A component of a gas turbine engine is provided. The component includes an external wall which, in use, is exposed on one surface thereof to working gas flowing through the engine. The component further includes effusion cooling holes formed in the external wall. In use, cooling air blows through the cooling holes to form a cooling film on the surface of the external wall exposed to the working gas. The component further includes an air inlet arrangement which receives the cooling air for distribution to the cooling holes. The component further includes a plurality of metering feeds and a plurality of supply plena. The metering feeds meter the cooling air from the air inlet arrangement to respective of the supply plena, which in turn supply the metered cooling air to respective portions of the cooling holes.

1 . A component of a gas turbine engine, the component including:
 an external wall which, in use, is exposed on one surface thereof to working gas flowing through the engine,   effusion cooling holes formed in the external wall, in use, cooling air blowing through the cooling holes to form a cooling film on the surface of the external wall exposed to the working gas, and   an air inlet arrangement which receives the cooling air for distribution to the cooling holes;   wherein the component further includes:   a plurality of metering feeds and a plurality of supply plena, the metering feeds metering the cooling air from the air inlet arrangement to respective of the supply plena, and the supply plena supplying the metered cooling air to respective portions of the cooling holes.   
     
     
         2 . A component according to  claim 1 , wherein the supply plena are partially defined by the other surface of the external wall. 
     
     
         3 . A component according to  claim 2 , wherein the metering feeds are configured to form impingements jets from the cooling air metered therethrough, the impingements jets impinging on said other surface. 
     
     
         4 . A component according to  claim 1 , further including a plurality of secondary plena which are partially defined by the other surface of the external wall, and are each in flow series between a respective supply plenum and its respective portion of the cooling holes. 
     
     
         5 . A component according to  claim 4 , further including a plurality of jet-forming passages which deliver the cooling air from the supply plena to the secondary plena, the jet-forming passages being configured to form impingements jets from the cooling air delivered therethrough, and the impingements jets impinging on said other surface. 
     
     
         6 . A component according to  claim 1  which further includes an inlet plenum in flow series between the air inlet arrangement and the supply plena, the metering feeds feeding the cooling air from the inlet plenum to respective of the supply plena. 
     
     
         7 . A component according to  claim 1 , wherein, in use, the pressure of the working gas to which the external wall is exposed varies from a leading edge to a trailing edge of the external wall, the supply plena, metering feeds and cooling holes being configured such that the pressure of the cooling air blowing through each cooling hole matches the local pressure of the working gas at that cooling hole. 
     
     
         8 . A component according to  claim 7 , wherein the working gas varies from a higher pressure to a lower pressure from the leading edge to the trailing edge of the external wall. 
     
     
         9 . A component according to  claim 1  which provides an endwall to the working gas annulus of the engine, the external wall being the endwall. 
     
     
         10 . A component according to  claim 9  which is a shroud segment. 
     
     
         11 . A component according to  claim 9  which is a turbine blade or a vane, a platform of the blade or vane forming the endwall. 
     
     
         12 . A component according to  claim 1  which is a combustor, the external wall at least partially defining a combustion chamber of the combustor. 
     
     
         13 . A gas turbine engine having one or more components according to  claim 1 .