Patent ID: 7927073

Claim:
A turbine airfoil, comprising: a generally elongated airfoil having a leading edge, a trailing edge, a pressure side wall and a suction side wall, an end wall extending generally orthogonal to the generally elongated airfoil and proximate an end of the generally elongated airfoil, and an internal cooling system formed from at least one cooling cavity in the turbine airfoil; at least one fillet cooling channel, passing proximate to an intersection between one of the side walls and the end wall; wherein a portion of the at least one fillet cooling channel is positioned proximate to the intersection between the one of the side walls and the end wall without breaching an outer surface of the turbine airfoil; a first impingement plate positioned in the internal cooling system proximate to an inner surface of the end wall, wherein a first impingement plate cavity is formed between the inner surface of the end wall and the first impingement plate; a second impingement plate positioned generally along the inner surface of the one of the side walls, wherein a second impingement plate cavity is formed between the inner surface of the one of the side walls and the second impingement plate, the at least one fillet cooling channel being positioned such that a first opening of the at least one fillet cooling channel is situated in an inner surface of the one of the side walls forming the second impingement plate cavity and such that a second opening of the at least one fillet cooling channel is situated in the inner surface of the end wall forming the first impingement plate cavity, whereby the first impingement plate cavity is in fluid communication with the second impingement plate cavity by the at least one fillet cooling channel; and a closure plug attached to the inner surface of the one of the side walls and proximate to an end of the second impingement plate closest to the end wall, thereby forming a second impingement cavity between the inner surface of the one of the side walls, the second impingement plate and the closure plug.