Patent ID: 8591189

Claim:
A turbine blade comprising: forward and aft serpentine cooling circuits, terminating in corresponding forward and aft impingement channels, with each circuit having two metered inlets for distributing more inlet flow to first passes thereof than to last passes thereof; a hollow airfoil having partitions joining opposite pressure and suction sides and spaced chordally between opposite leading and trailing edges to define said serpentine circuits, and cooperating impingement channels; a dovetail integrally joined to said airfoil at a platform, and including four inlet channels separately joined to said serpentine circuits; and a metering plate joined to said dovetail to cover said four inlet channels and distribute more flow to said first passes than to said last passes; wherein: an tip airfoil tip of said hollow airfoil comprises a tip floor recessed therein to directly cover said forward and aft serpentine circuits; said four inlet channels have larger flow areas than said serpentine circuits; and said metering plate includes first, second, third, and fourth aperture inlets being smaller in flow area than said four inlet channels to correspondingly meter said cooling flow therethrough.