Patent ID: 9068472
Filing Date: 2015-06-30
Classification: F01D,F05D

Abstract:
1. A component of a turbine stage of a gas turbine engine, the component forming an endwall for a working gas annulus of the turbine stage, and the component having: one or more internal plena behind the endwall which, in use, contain a flow of cooling air, and a plurality of exhaust holes in the endwall, the exhaust holes connecting the one or more internal plena to a gas-washed surface of the endwall such that the cooling air effuses through the exhaust holes to form a cooling film over the gas-washed surface; wherein: each exhaust hole has a flow cross-sectional area which is greater at an intermediate position between the entrance of the exhaust hole from a respective plenum of the one or more internal plena and the exit of the exhaust hole to the gas-washed surface, the entrance, the intermediate position, and the exit of each of the exhaust holes are coaxial, and the flow cross-sectional area at the intermediate position of each of the exhaust holes being greater than both (i) a cross-sectional area of the entrance of each of the exhaust holes and (ii) a cross-sectional area of the exit of each of the exhaust holes, wherein a cavity of each exhaust hole being formed by a pair of base-to-base frustocones.