Abstract: A turbine bucket assembly and turbine system are disclosed. The turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the platform and a tip segment coupled to the root segment, the tip segment having a second axial length, which is less than the first axial length; and a turbine wheel defining a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material, the root segment material and the turbine wheel material having a lower heat resistance and a higher thermal expansion than the tip segment material.

Abstract: Embodiments of the disclosure provide a shaft assembly including: a first shaft extending through a compressor and a turbine of the turbomachine; a second shaft coupled to the first shaft through a load coupling component; a generator mounted on the second shaft, wherein the turbine drives the generator; a plurality of mono-type low-loss bearings supporting the first and second shafts at the compressor, turbine, and generator; and a plurality of rotating blade structures within the compressor and the turbine of the turbomachine, wherein at least one of the plurality of rotating blade structures in the compressor includes a low-density material, and at least one of the plurality of rotating blade structures in the turbine includes the low-density material.

Abstract: A compressor includes a first stage of stator vanes having a first position and a second group of stator vanes arranged in two or more stages downstream from the first stage of stator vanes, each stage having a respective second position. A first actuator is engaged with the first stage of stator vanes, and a second actuator is engaged with a bar connecting the second group of stator vanes. A method for operating a compressor includes adjusting a first position of a first plurality of stator vanes and adjusting the respective second positions of a second group of stator vanes separately from the first position of the first stage of stator vanes.

Abstract: A system is provided, including an airfoil. The airfoil includes a first suction portion of a nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y, and Z of a suction side as set forth in TABLE I to a maximum of three decimal places, wherein the X and Y values of the suction side are coordinate values that couple together to define suction side sections of the first suction portion of the nominal airfoil profile at each Z coordinate value, the suction side sections of the first suction portion of the nominal airfoil profile are coupled together to define the first suction portion, the airfoil includes an airfoil length along a Z axis, the first suction portion comprises a first portion length along the Z axis, the first portion length is less than or equal to the airfoil length, and the Cartesian coordinate values of X, Y, and Z are non-dimensional values convertible to dimensional distances.

Abstract: A system is provided, including an airfoil. The airfoil includes a first suction portion of a nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y, and Z of a suction side as set forth in TABLE I to a maximum of three decimal places, wherein the X and Y values of the suction side are coordinate values that couple together to define suction side sections of the first suction portion of the nominal airfoil profile at each Z coordinate value, the suction side sections of the first suction portion of the nominal airfoil profile are coupled together to define the first suction portion, the airfoil includes an airfoil length along a Z axis, the first suction portion comprises a first portion length along the Z axis, the first portion length is less than or equal to the airfoil length, and the Cartesian coordinate values of X, Y, and Z are non-dimensional values convertible to dimensional distances.

Abstract: In some embodiments, a gamma titanium aluminide alloy consists essentially of, in atomic percent, 38 to about 50% aluminum, 1 to about 6% niobium, 0.25 to about 2% tungsten, 0.01 to about 1.5% boron, up to about 1% carbon, optionally up to about 2% chromium, optionally up to about 2% vanadium, up to about 2% manganese, and the balance titanium and incidental impurities. In some embodiments, the gamma titanium aluminide alloy forms at least a portion of a gas turbine component. In some embodiments, a gamma titanium aluminide alloy, consists essentially of, in atomic percent, about 40 to about 50% aluminum, about 1 to about 5% niobium, about 0.3 to about 1% tungsten, about 0.1 to about 0.3% boron, up to about 0.1% carbon, up to about 2% chromium, up to about 2% vanadium, up to about 2% manganese, up to about 1% molybdenum, and the balance titanium and incidental impurities.

Abstract: In some embodiments, a gamma titanium aluminide alloy consists essentially of, in atomic percent, about 38 to about 50% aluminum, about 6% niobium, about 0.25 to about 2% tungsten, optionally up to about 1.5% boron, about 0.01 to about 1.0% carbon, optionally up to about 2% chromium, optionally up to about 2% vanadium, optionally up to about 2% manganese, and the balance titanium and incidental impurities. In some embodiments, the gamma titanium aluminide alloy forms at least a portion of a gas turbine component. In some embodiments, a gamma titanium aluminide alloy, consisting essentially of, in atomic percent, about 40 to about 50% aluminum, about 3 to about 5% niobium, about 0.5 to about 1.5% tungsten, about 0.01 to about 1.5% boron, about 0.01 to about 1.0% carbon, optionally up to about 2% chromium, optionally up to about 2% vanadium, optionally up to about 2% manganese, and the balance titanium and incidental impurities.

Abstract: A system is provided, including an airfoil. The airfoil includes a first suction portion of a nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y, and Z of a suction side as set forth in TABLE I to a maximum of three decimal places, wherein the X and Y values of the suction side are coordinate values that couple together to define suction side sections of the first suction portion of the nominal airfoil profile at each Z coordinate value, the suction side sections of the first suction portion of the nominal airfoil profile are coupled together to define the first suction portion, the airfoil includes an airfoil length along a Z axis, the first suction portion comprises a first portion length along the Z axis, the first portion length is less than or equal to the airfoil length, and the Cartesian coordinate values of X, Y, and Z are non-dimensional values convertible to dimensional distances.

Abstract: A system is provided, including an airfoil. The airfoil includes a first suction portion of a nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y, and Z of a suction side as set forth in TABLE I to a maximum of three decimal places, wherein the X and Y values of the suction side are coordinate values that couple together to define suction side sections of the first suction portion of the nominal airfoil profile at each Z coordinate value, the suction side sections of the first suction portion of the nominal airfoil profile are coupled together to define the first suction portion, the airfoil includes an airfoil length along a Z axis, the first suction portion comprises a first portion length along the Z axis, the first portion length is less than or equal to the airfoil length, and the Cartesian coordinate values of X, Y, and Z are non-dimensional values convertible to dimensional distances.

Abstract: Mechanical drive architectures can include a gas turbine having a compressor section, a turbine section, and a combustor section. A load compressor is driven by the gas turbine. A rotor shaft extends through the gas turbine and the load compressor. The rotor shaft has rotating blades arranged in a circumferential array to define a plurality of moving blade rows in the gas turbine and the load compressor. At least one of the rotating blades in one of the gas turbine and the load compressor includes a low-density material. Bearings support the rotor shaft within the gas turbine and the load compressor, wherein at least one of the bearings is a hybrid-type low-loss bearing.

Abstract: A compressor includes a first stage of stator vanes having a first position and a second group of stator vanes arranged in two or more stages downstream from the first stage of stator vanes, each stage having a respective second position. A first actuator is engaged with the first stage of stator vanes, and a second actuator is engaged with a bar connecting the second group of stator vanes. A method for operating a compressor includes adjusting a first position of a first plurality of stator vanes and adjusting the respective second positions of a second group of stator vanes separately from the first position of the first stage of stator vanes.

Abstract: A multi-stage axial compressor arrangement is disclosed that uses a compressor speed reducer to rotate the moving blades in the forward stages of the compressor at a slower rotational speed than the moving blades in the mid stages and the aft stages of the compressor. Slowing the rotational speed of the moving blades in the forward stages in relation to the blades in the mid stages and the aft stages, enables the multi-stage axial compressor to deliver a high airflow rate while overcoming excessive attachment stresses that is typically experienced in the large rotating blades of the forward stages of the compressor.

Abstract: Power train architectures with hybrid-type low-loss bearings and low-density materials are disclosed. The gas turbine used in these architectures can include a compressor section, a turbine section, and a combustor section coupled to the compressor and turbine sections. A generator, coupled to the rotor shaft, is driven by the turbine section. The compressor section, the turbine section, and the generator include rotating components, at least one of which is a low-density material. Bearings support the rotor shaft within the compressor section, the turbine section and the generator, wherein at least one of the bearings is a hybrid-type low-loss bearing.

Abstract: Power train architectures with mono-type low-loss bearings and low-density materials are disclosed. The gas turbine used in these architectures can include a compressor section, a turbine section, and a combustor section. A generator, coupled to the rotor shaft, is driven by the turbine section. The compressor section, the turbine section, and the generator include rotating components, at least one of the rotating components in one of the compressor section, the turbine section, and the generator including a low-density material. Bearings support the rotor shaft within the compressor section, the turbine section and the generator, wherein at least one of the bearings is a mono-type low-loss bearing.

Abstract: Mechanical drive architectures can include a gas turbine having a compressor section, a turbine section, and a combustor section. A load compressor is driven by the gas turbine. A rotor shaft extends through the gas turbine and the load compressor. At least one of the rotating components in one of the gas turbine and the load compressor includes a low-density material. Bearings support the rotor shaft within the gas turbine and the load compressor, at least one of the bearings being a mono-type low-loss bearing.

Abstract: A turbine bucket assembly and turbine system are disclosed. The assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a non-segmented airfoil extending radially outward from the integral platform and having a tip end with a second axial length, the second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The joint and the non-segmented airfoil include a turbine bucket material, and the turbine wheel includes a turbine wheel material, the turbine wheel material having a lower heat resistance and a higher thermal expansion than the turbine bucket material.

Abstract: A turbine bucket assembly and turbine system are disclosed. The turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the platform and a tip segment coupled to the root segment, the tip segment having a second axial length, which is less than the first axial length; and a turbine wheel defining a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material, the root segment material and the turbine wheel material having a lower heat resistance and a higher thermal expansion than the tip segment material.

Abstract: A turbine bucket assembly and turbine system are disclosed. The turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a non-segmented airfoil having a root section and a tip section integral with the root section, the tip section having a tip end with a second axial length, the second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The turbine wheel includes a turbine wheel material and the single-lobe joint and the non-segmented airfoil include a turbine bucket material, the turbine bucket material having a higher heat resistance and a lower thermal expansion than the turbine wheel material.

Abstract: A turbine bucket assembly and turbine system are disclosed. The assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the platform and a tip segment coupled to the root segment, the tip segment having a second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material having a lower heat resistance and a higher thermal expansion than the root segment material and the tip segment material.

Abstract: A turbine bucket assembly and turbine system are disclosed. The assembly includes a multi-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the platform and a tip segment coupled to the root segment, the tip segment having a second axial length less than the first axial length; and a turbine wheel defining a receptacle with a geometry corresponding to the multi-lobe joint and being coupled to the multi-lobe joint. A tip segment material, a root segment material, and a turbine wheel material are selected, such that the turbine wheel material and the root segment material have a lower heat resistance and a higher thermal expansion than the tip segment material.