Complementary cooled turbine nozzle

摘要

A turbine nozzle (26) includes outer and inner bands (30,32) integrally joined to a vane (34) having a three-pass serpentine flow circuit between opposite pressure and suction sidewalls (36,38). The outer band includes an inlet (54) for channeling cooling air into a first channel (44) of the circuit located behind a leading edge (40) of the vane. A first outlet (56) is disposed in the inner band at the bottom of the first channel where it joins the second channel (46) of the circuit. A second outlet (58) is also disposed in the inner band at the bottom of a third channel (48) of the circuit which is disposed in flow communication with the second channel. The first channel (44) behind the leading edge (40) is smooth except for corresponding rows of first and second turbulators (62,64) spaced laterally apart. The first turbulators (62) bridge the pressure and suction sidewalls directly behind the leading edge, and the second turbulators (64) are disposed behind the suction sidewall.