초록 ▼

A film cooling passage through the external wall of a hollow airfoil for a gas turbine engine has a metering section in series flow relation with a diffusing section leading to the passage outlet at the external surface of the airfoil over which a hot gas flows during operation. The diffusing sectio

A film cooling passage through the external wall of a hollow airfoil for a gas turbine engine has a metering section in series flow relation with a diffusing section leading to the passage outlet at the external surface of the airfoil over which a hot gas flows during operation. The diffusing section is generally rectangular in cross section perpendicular to the axis of the passage. Upstream and downstream longitudinally extending, spaced apart, facing surfaces of the diffusing section are joined together by a pair of spaced apart side walls which face each other and diverge from each other in the longitudinal direction toward the outlet of the passage. These side walls blend, along their length, with the downstream surface as a smooth curve of large radius. The diameter of the corner curvature of the passage is on the same order of magnitude as the distance between the upstream and downstream surfaces of the diffusing section at the location in question. The large corner curvatures, as opposed to filet radii, allow the side walls to diverge from each other at a greater angle without separation of the coolant fluid therefrom, permitting the spreading of smaller amounts of coolant air over a larger area of the airfoil external surface.

대표청구항 ▼

A cooled wall having an outer surface adapted to be exposed to a hot gas stream flowing in a downstream direction over said outer surface, and an inner surface adapted to define a portion of a coolant compartment for receiving coolant therein under pressure, a coolant passage within said wall, said

A cooled wall having an outer surface adapted to be exposed to a hot gas stream flowing in a downstream direction over said outer surface, and an inner surface adapted to define a portion of a coolant compartment for receiving coolant therein under pressure, a coolant passage within said wall, said passage having an outlet over which the hot gas flows in said downstream direction and including a metering section in series flow relation with a diffusing section, said diffusing section having an inlet and outlet, said metering section adapted to receive a flow of coolant from the coolant compartment and to control the rate of flow of coolant fluid through said passage, said diffusing section including an upstream surface spaced apart from and facing a downstream surface, said first and second surfaces being parallel to each other or diverging from each other toward said outer surface and intersecting said outer surface of said wall at a shallow angle to define said outlet of said coolant passage, said outer surface extending downstream of said passage outlet, said coolant passage being oriented to direct the flow of coolant from said passage outlet such that is has a component of velocity in the downstream direction and forms a film of coolant over said outer surface downstream of said passage outlet, said first surface forming an upstream edge of said passage outlet where it intersects with said outer wall and said second surface defining a downstream edge of said passage outlet where it intersects with said outer wall, said diffusing section including side surfaces facing each other, interconnecting said upstream and downstream surfaces and diverging from each other toward the outlet of said diffusing section, each of said side surfaces blending along substantially its full length with said downstream surface as a smooth curve having a diameter on the order of magnitude of the distance between said upstream and downstream surfaces at the location of said blending.