Patent attributes
A serpentine cooling circuit (AFT) in a turbine airfoil (34A) starting from a radial feed channel (C1), and progressing axially (65) in alternating tangential directions through interconnected channels (C1, C2, C3) formed between partitions (T1, T2, J1). At least one of the partitions (T1, T2) has a T-shaped transverse section, with a base portion (67) extending from a suction or pressure side wall (64, 62) of the airfoil, and a crossing portion (68, 69) parallel to, and not directly attached to, the opposite pressure or suction side wall (62, 64). Each crossing portion bounds a near-wall passage (N1, N2) adjacent to the opposite pressure or suction side wall (62, 64). Each near-wall passage may have a smaller flow aperture area than one, or each, of two adjacent connected channels (C1, C2, C3). The serpentine circuit (AFT) may follow a forward cooling circuit (FWD) in the airfoil (34A).
