Three-Dimensional Optimization of a Gas Turbine Disk and Blade Attachment

A new three-dimensional finite-element stress simulation is described and applied to design optimization of a turbine disk/blade attachment. Isoparametric elements are employed, with the standard elements being a general parabolic conoid and a variable thickness triangle. The stress field obtained is improved with the use of a conjugate approximation. A parametric study is used to select optimum attachment geometry. The analysis model includes complex airfoil geometry and a nonzero broach angle.