Patent ID: 8727724

Claim:
A turbine bucket, comprising: a shank interconnectable with a rotor and formed to accommodate coolant therein; and an airfoil blade coupled to a radially outward portion of the shank and including a body having opposing pressure and suction surfaces extending between opposing leading and trailing edges, the body being formed to define a plurality of substantially radially extending cooling holes therein, each of which is disposed to be solely receptive of the coolant accommodated within the shank for removing heat from the body, the plurality of the cooling holes being arranged in groups of singular and multiple cooling holes comprising: cooling holes defined as having a substantially circular cross-sectional shape at a predefined radial position of the body, and cooling holes defined as having a substantially non-circular cross-sectional shape at the predefined radial position of the body and with elongated sidewalls having profiles that are substantially parallel with those of the pressure and suction surfaces; and wherein one of the cooling hole groups is proximate to a trailing edge of the airfoil blade and defines a grouping of proximal cooling holes of mixed shapes with similarly-shaped cooling holes within the grouping having different sizes.