The field of the disclosure relates generally to rotary machines, and more particularly, to a tip shroud of a turbine blade that includes notch features.
At least some known rotary machines include a compressor, a combustor coupled downstream from the compressor, a turbine coupled downstream from the combustor, and a rotor shaft rotatably coupled between the compressor and the turbine. Some known turbines include at least one rotor disk coupled to the rotor shaft, and a plurality of circumferentially-spaced turbine blades that extend outward from each rotor disk to define a stage of the turbine. Each turbine blade includes an airfoil that extends radially outward from a platform towards a turbine casing.
At least some known turbine blades include a shroud that extends from an outer tip end of the airfoil to reduce gas flow leakage between the airfoil and the turbine casing. An operational life cycle of at least some latter stage turbine blade tip shrouds may be limited by creep. Creep is the tendency of a material to deform over time when exposed to a combination of mechanical loading and high temperature. Turbine shroud creep rate may be greatly impacted by the high temperatures often seen at the shroud. To counter the effects of high temperatures, at least some known turbine blades include an internal cooling circuit, such as an interior tip shroud core cavity, or plenum, and/or passages that run transversely from the plenum toward the outer edges of the shroud. However, known tip shroud core plenums generally increase the complexity and expense of manufacture of the tip shroud, and impose design limits on other properties of the shroud, such as shape and thickness. Additionally, at least some known tip shrouds are shaped to reduce an area of the shroud that requires cooling. However, an ability to reduce the shroud area is limited by a need for the shrouds to cooperate structurally with adjacent shrouds.