Patent ID: 7527475

Claim:
A turbine airfoil for use in a gas turbine engine, the airfoil including a pressure side and a suction side, a leading edge and a trailing edge, and a tip region, the airfoil comprising: a collector cavity formed within the airfoil; a cooling air supply passage to deliver a cooling air from an external source to the airfoil; a near-wall cooling passage including a pressure side radial extending cooling channel and a suction side radial extending cooling channel, the two channels being in fluid communication at the airfoil tip region; an entrance of the near-wall cooling passage being in fluid communication with the cooling air supply passage, and an exit of the near-wall cooling passage being in fluid communication with the collector cavity; a second near wall cooling passage including a second pressure side radial extending channel and a second suction side radial extending channel in fluid communication with each other at the airfoil tip region; the first near wall cooling passage being fluidly connected to the supply passage and the collector cavity such that cooling air flows into the pressure side channel before the suction side channel; the second near wall cooling passage being fluidly connected to the supply passage and the collector cavity such that cooling air flows into the suction side channel before the pressure side channel; and, a plurality of film cooling holes in fluid communication with the collector cavity, whereby the cooling air passes through the cooling channels and into the collector cavity before passing through the film cooling holes.