Integrally Cast Turbine Rotor for High Volume Production

The goal is to design an integrally cast wheel with blades which can be produced from high volume production tooling. An automated procedure is described to determine the optimum radial orientation, or “stacking,” of turbine rotor blade sections to give a design which satisfies both high production manufacturing and rotor structural requirements. High production manufacturing requires that the spaces between blades be pulled away from the wheel in a generally radial direction to release the wax replica of the wheel from the tooling. Structural requirements are expressed in terms of bending stress constraints. A pullability index is defined to indicate the amount of interference to be encountered in removing the tooling. This index is optimized with respect to the direction of removal of the tooling. Bending stress requirements are simultaneously satisfied.