Airfoil cooling passage trailing edge flow restriction

A cooled gas turbine engine airfoil comprising a hollow body defining an internal cooling path through which a cooling fluid is circulated to convectively cool the airfoil, at least one exit aperture through which the cooling fluid leaves the airfoil, the flow of cooling air leaving the airfoil being metered by a series of metering orifices defined in a rib structure extending across the cooling path immediately upstream of said at least one exit aperture, wherein the rib structure and the hollow body are of unitary construction.

A casting core for use in the manufacturing of a hollow gas turbine engine airfoil, comprising a solid body adapted to be used for forming an internal geometry of an airfoil having an internal cooling path, a row of primary apertures defined through said solid body, each pair of adjacent primary apertures being spaced by a primary rib forming a corresponding metering aperture in the gas turbine engine airfoil, and a row of secondary apertures through said solid body, each pair of adjacent secondary apertures being spaced by a secondary rib forming a corresponding exit aperture in a trailing edge region of the gas turbine engine airfoil, and wherein the primary ribs are smaller in size than said secondary ribs and said primary ribs are immediately upstream of said secondary ribs.

A method of making an internally cooled airfoil, comprising the steps of:

• providing an airfoil having an internal cooling path terminating in at least one exit aperture, providing said exit aperture in a size which permits satisfactory manufacturability, providing a metering rib immediately upstream of the exit aperture with at least one orifice, the orifice sized to restrict the flow delivered to the exit aperture to thereby control the overall airflow exiting the airfoil.