AIRFOIL SHAPE FOR TURBINE BUCKET

PROBLEM TO BE SOLVED: To provide a turbine bucket in which profile sections are joined smoothly to one another to form a complete airfoil shape. SOLUTION: Fourth stage turbine buckets (28) have airfoil profiles substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in Table I. In Table I, the X and Y values are in inches and the Z values are non-dimensional values from 0 to 1 convertible to Z distances in inches by multiplying the Z values by the height of the airfoil in inches. The X and Y values are distances which, when connected by smooth continuous arcs, define airfoil profile sections (48) at each distance Z. The profile sections at each distance Z are joined smoothly to one another to form a complete airfoil shape. The X and Y distances may be scalable as a function of the same constant or number to provide a scaled up or scaled down airfoil section for the bucket. The nominal airfoil given by the X, Y and Z distances lies within an envelope of ±0.150 inches in directions vertical to the surface of the airfoil. COPYRIGHT: (C)2005,JPO&NCIPI