Conical tip shroud fillet for a turbine bucket

摘要

A turbine bucket airfoil has a conical fillet about the intersection of the airfoil tip and tip shroud having a nominal profile in accordance with coordinate values of X and Y, offset 1, offset 2 and Rho set forth in Table I. The shape parameters of offset 1, offset 2 and Rho define the configuration of the fillet at the specified X and Y locations about the fillet to provide a fillet configuration accommodating high localized stresses. The fillet shape may be parabolic, elliptical or hyperbolic as a function of the value of the shape parameter ratio of $\frac{\mathrm{D1}}{\mathrm{D1}+\mathrm{D2}}$ at each X, Y location where D1 is a distance between an intermediate point along a chord between edge points determined by offsets O1 and O2 and a shoulder point on the fillet surface and D2 is a distance between the shoulder point and an apex location at the intersection of the airfoil tip and tip shroud.