Patent ID: 7520725

Claim:
An airfoil for use in a turbine, the airfoil including a pressure side and a suction side, and a leading edge and a trailing edge, and a cooing air supply cavity within the airfoil to supply cooling air to the leading edge region of the airfoil, the airfoil comprising: an impingement cavity located between the leading edge of the airfoil and the cooling air supply cavity; at least one first metering hole to meter cooling air flow from the cooling supply cavity into the impingement cavity; a plurality of multi-impingement cavities located between the impingement cavity and the leading edge surface of the airfoil; at least one second metering hole associated with each of the multi-impingement cavities to meter cooling air flow from the impingement cavity into the respective multi-impingement cavity; a plurality of film cooling holes associated with each of the multi-impingement cavities to discharge cooling air to the leading edge surface of the airfoil; and, the plurality of multi-impingement cavities comprises a first multi-impingement cavity located at the nose of the leading edge region of the airfoil, a second multi-impingement cavity located adjacent to the first multi-impingement cavity and on the pressure side thereof, and a third multi-impingement cavity located adjacent to the first multi-impingement cavity and on the suction side thereof.