A cooled turbine vane platform comprising forward, midchord and aft cooling chambers in the platform

A turbine airfoil, comprising:

• a generally elongated, hollow airfoil having a leading edge, a trailing edge, a pressure side, a suction side, an inner endwall at a first end and an outer endwall at a second end that is generally on an opposite side of the generally elongated hollow airfoil from the first end, and a cooling system formed from at least one cavity in the elongated, hollow airfoil;
• wherein the inner endwall includes at least one aft cooling chamber and at least one midchord cooling chamber positioned upstream from the at least one aft cooling chamber;
• wherein the at least one aft cooling chamber is positioned between the at least one midchord cooling chamber and a downstream edge of the inner endwall;
• at least one midchord film cooling channel extending from the at least one midchord cooling chamber, wherein the at least one midchord film cooling channel has at least one inlet in the at least one midchord cooling chamber and at least one outlet positioned closer to the downstream edge of the inner endwall than an upstream wall forming the at least one aft cooling chamber, thereby placing the at least one outlet of the at least one midchord film cooling channel downstream of the upstream wall forming the at least one aft cooling chamber;
• and
• wherein an outer surface of the inner endwall that intersects with the generally elongated, hollow airfoil is perforationless without any outlet from a channel extending from the at least one aft cooling chamber.