US Patent 7789626 Turbine blade with showerhead film cooling holes

A turbine blade used in a gas turbine engine, the blade having a showerhead film cooling hole arrangement along the leading edge of the blade, the showerhead arrangement including three rows of film cooling holes with a middle row being aligned with the stagnation point, a second row on the pressure side of the stagnation point, and the third row on the suction side of the stagnation point. The film cooling holes can be oriented at any angle within each row, and the cooling holes spiral within the airfoil wall to promote heat transfer to the cooling air flow. In large turbine airfoils, very fine cooling passages can be formed in the airfoil wall using the small diameter ceramic core ties used in the present invention.