Patent ID: 7137780

Claim:
A turbine blade, comprising: a generally elongated blade having a leading edge, a trailing edge, and a tip at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, at least one cavity forming a cooling system in the blade, and at least one outer wall defining the at least one cavity forming at least a portion of the cooling system; wherein the cooling system comprises at least one serpentine cooling channel formed from a first leg extending generally from the root towards the tip, a second leg in communication with the first leg and extending towards the root, and a third leg in communication with the second leg through a root turn and extending generally towards the tip; and at least one refresh hole extending between the first leg and the second leg and positioned proximate to the root turn to direct cooling fluid into the upstream portion of the root turn; wherein the at least one refresh hole is positioned between about 15 degrees and about 75 degrees relative to a direction of flow of the cooling fluid through the second leg and positioned immediately downstream of a mouth of an upstream portion of the turn.