TURBINE AIRFOIL WITH CAST PLATFORM COOLING CIRCUIT

摘要

A turbine airfoil apparatus (10, 110) includes: an airfoil (18, 118) including a concave pressure sidewall (20, 120) and a convex suction sidewall (22, 122) joined together at a leading edge (24, 124) and a trailing edge (26, 126); an endwall (16, 116) projecting laterally outwardly from the airfoil (18, 118) at one spanwise end thereof, the endwall (16, 116) having an outer surface (42, 142) facing the airfoil 18, 118) and an opposing inner surface (40, 140); a plenum (44, 144) defined within the endwall (16, 116) between the inner (40, 140) and outer surfaces (42, 142) wherein the plenum (44, 144) is forked in plan view, with at least two branches, each branch having a throat (2, 4, 102, 104) disposed at its upstream end; and at least one film cooling hole (48, 148) passing through the outer surface (42, 142) and communicating with the plenum (44, 144).