Abstract: A rotor wheel assembly has a rotor wheel including a plurality of dovetail slots. The rotor wheel assembly includes a bucket closure assembly having a leading auxiliary bucket with a dovetail coupled to a dovetail slot and an integral cover having a back side edge oriented at a first angle relative to the rotor wheel rotation axis. The bucket closure assembly includes a closure bucket having a dovetail coupled to a dovetail slot and an integral cover having a front side and a back side edge, where the back side edge is oriented to a second angle and the front side edge is parallel to the back side edge of the leading auxiliary bucket. The bucket closure assembly includes a trailing auxiliary bucket having a dovetail coupled to a dovetail slot and an integral cover having a front side edge parallel to the back side edge of the closure bucket.

Abstract: A rotor wheel assembly includes a rotor wheel having a plurality of dovetail slots spaced circumferentially about a peripheral surface of the rotor wheel. The rotor wheel also has a plurality of notches formed in the peripheral surface. The rotor wheel assembly includes at least one bucket having an integral cover, an airfoil, a dovetail, and a platform having a first surface and an opposite second surface. The first surface of the platform includes a keyway. The keyway has an opposing tapered surface oriented at a first angle relative to the first surface of the platform. Furthermore, the rotor wheel assembly includes a wedge key having first face that is oriented substantially parallel to the first surface of the platform and an opposite second face that is oriented at the first angle relative to the first face, such that the second face is substantially parallel to the taper surface.

Abstract: A rotor wheel assembly has a rotor wheel including a plurality of dovetail slots. The rotor wheel assembly includes a bucket closure assembly having a leading auxiliary bucket with a dovetail coupled to a dovetail slot and an integral cover having a back side edge oriented at a first angle relative to the rotor wheel rotation axis. The bucket closure assembly includes a closure bucket having a dovetail coupled to a dovetail slot and an integral cover having a front side and a back side edge, where the back side edge is oriented to a second angle and the front side edge is parallel to the back side edge of the leading auxiliary bucket. The bucket closure assembly includes a trailing auxiliary bucket having a dovetail coupled to a dovetail slot and an integral cover having a front side edge parallel to the back side edge of the closure bucket.

Abstract: A rotor wheel assembly includes a rotor wheel having a plurality of dovetail slots spaced circumferentially about a peripheral surface of the rotor wheel. The rotor wheel also has a plurality of notches formed in the peripheral surface. The rotor wheel assembly includes at least one bucket having an integral cover, an airfoil, a dovetail, and a platform having a first surface and an opposite second surface. The first surface of the platform includes a keyway. The keyway has an opposing tapered surface oriented at a first angle relative to the first surface of the platform. Furthermore, the rotor wheel assembly includes a wedge key having first face that is oriented substantially parallel to the first surface of the platform and an opposite second face that is oriented at the first angle relative to the first face, such that the second face is substantially parallel to the taper surface.

Abstract: A method has been developed for predicting a remaining operational life of a turbine component including: obtaining crack flaw data regarding current crack flaws in the turbine component; using the crack flaw data with data regarding the structure and operating conditions of the turbine component to determine force loads applied to the turbine component and generate crack propagation data; applying a probalistic analysis to the crack flaw data and the generated crack propagation data to generate a statistical distribution of crack data, and applying the statistical distribution of crack data to predict a time to failure of the component by iteratively determining the force loads for successive periods of time.