Turbine airfoil with near-wall mini serpentine cooling channels

摘要

A turbine airfoil includes a plurality of mini serpentine flow passages to provide near wall cooling to a thin thermal skin that forms the outer airfoil surface. The airfoil includes a spar with a number spanwise extending external ribs with a series of mini pin fins extending between adjacent ribs. The thin skin includes an arrangement of mini pin fins that, when bonded to the spar, form the serpentine flow passages. The thin thermal skin is bonded to the spar to form the airfoil. The mini serpentine flow passages can be formed in the airfoil walls with a small size that cannot be formed in an airfoil formed by the investment casting process. With the use of a thin thermal skin, higher levels of cooling can be produced using the near wall cooling process.