Patent ID: 7611330

Claim:
A turbine blade having a root portion and an airfoil portion, the root having a cooling air supply passage to supply cooling air to the airfoil portion, the blade comprising: an first serpentine flow cooling circuit including a first leg formed from a cooling channel on the pressure side of the blade, a second leg formed from a cooling channel on the suction side and adjacent to the first leg, and a third leg formed between the pressure side and the suction side and located forward of from the first and second legs; a second serpentine flow cooling circuit located downstream from the first serpentine flow cooling circuit and including a first leg formed from a channel located on the pressure side of the blade, a second leg formed from a channel located on the suction side and adjacent to the first leg, and a third leg formed from a channel between the pressure side and the suction side; a plurality of cooling air exit holes in communication with the third leg of the second serpentine flow circuit; and, a showerhead arrangement and a leading edge cooling channel located in the leading edge region of the blade and in communication with the third leg of the first serpentine flow circuit through a plurality of metering holes.