Methods, apparatus, systems and articles of manufacture are disclosed to methods and apparatus for gas turbine bending isolation. An example mechanical interface to couple a first section of a gas turbine to a second section of the gas turbine, the mechanical interface comprising a first mating surface disposed on the first section, and a second mating surface disposed on the second section and circumferentially around the first mating surface, wherein the coupling of the first mating surface to the second mating surface enables the first section to rotate about the mechanical interface during operation of the gas turbine.

An example embodiment of a turbine engine assembly includes a low spool including a low spool accessory drive gear driven by a low rotor shaft, a high spool including a high spool accessory drive gear driven by a high rotor shaft concentric around a portion of the low rotor shaft, and a differential gear assembly adapted to offtake power from rotation of one or both of the low spool and the high spool to drive one or more accessory loads. The differential gear assembly includes a differential bullgear and one or more idler gears each including a plurality of teeth meshed with the low spool accessory drive gear and the high spool accessory drive gear, and a bearing surface. The differential bull gear includes a plurality of teeth and a corresponding at least one bearing surface engaging with the bearing surface of each of the one or more idler gears. The plurality of teeth are adapted to mesh with an accessory drive system to transfer the power offtake and drive the one or more accessory loads.

A turbomachine engine including a high-pressure compressor, a high-pressure turbine, a combustion chamber in flow communication with the high-pressure compressor and the high-pressure turbine, and a power turbine in flow communication with the high-pressure turbine. At least one of the high-pressure compressor, the high-pressure turbine, and the power turbine comprises a ceramic matrix composite (CMC) material. The turbomachine engine includes a low-pressure shaft coupled to the power turbine and characterized by a midshaft rating (MSR) between two hundred (ft/sec).sup.1/2 and three hundred (ft/sec).sup.1/2. The low-pressure shaft has a redline speed between fifty and two hundred fifty feet per second (ft/sec). The turbomachine engine is configured to operate up to the redline speed without passing through a critical speed associated with a first-order bending mode of the low-pressure shaft.

A turbomachine engine includes a fan section having a fan shaft, and a core engine having one or more compressor sections, one or more turbine sections that includes a power turbine, and a combustion chamber in flow communication with the compressor sections and turbine sections. The turbomachine engine includes a low-speed shaft coupled to the power turbine and having a midshaft that extends from a forward bearing to an aft bearing. The low-speed shaft is characterized by a midshaft rating (MSR) between two hundred (ft/sec).sup.½ and three hundred (ft/sec).sup.½. The low-speed shaft has a redline speed between fifty and two hundred fifty feet per second (ft/sec). The turbomachine engine includes a gearbox assembly that couples the fan shaft to the low-speed shaft and characterized by a gearbox assembly mode less than 95% of a midshaft mode of the midshaft or greater than 105% of the midshaft mode.

In an embodiment, a gas turbine system is provided. The gas turbine system may include a supplementary air system and a flow diffuser configured to receive compressed air from the supplementary air system. The gas turbine system further comprises a gas turbine compressor downstream the flow diffuser, a combustor downstream the gas turbine compressor, a turbine downstream the combustor, and a turbine haft. The turbine shaft comprises a thrust bearing and a clutch. When the gas turbine system is operating, the gas turbine compressor does not consume electricity.

An aircraft engine has: a first component and a second component coaxially mounted about a central axis; a flow passage extending within an annular gap defined radially between the first component and the second component, the flow passage fluidly connecting a first zone to a second zone; a seal disposed in the flow passage between the first zone and the second zone, the seal extending from a seal base secured to the first component to a seal end radially spaced apart from the seal base; a deflector located downstream of the seal relative to a first flow flowing from the first zone to the second zone through the seal, the deflector extending from a deflector base secured to the second component to a deflector end radially spaced apart from the deflector base; and a radial gap defined radially between the seal end and the deflector end.

A gas turbine engine, includes: an engine core including a turbine, compressor, and shaft system connecting the turbine to the compressor, and forming a torque path therebetween. The shaft system is axially located by a thrust bearing located forward of the turbine, and the engine is configured, in the event of a shaft break which divides the shaft system into a front portion located by the thrust bearing and a rear portion unlocated by the thrust bearing, the rear portion is free to move axially rearwardly under a gas load. The engine further includes a shaft break detector having a forward speed sensor configured to measure a rotational speed of the front portion of the shaft system, and a rear microwave sensor configured to measure a rotational speed of the rear portion of the shaft system, wherein a shaft break can be detected based on differences in the measured speeds.

A method for compacting an anticorrosion coating includes projecting water soluble particles.

Apparatuses are provided herein useful to sealing a gap between a movable flap and a stationary structure, such as a gap between a gas turbine engine nozzle flap and a corresponding sidewall. An apparatus for sealing such a gap may be a dynamic skirted leaf seal which may include a flap arm, a wall arm opposite the flap arm, and a support arm disposed between the flap and wall arms. A distal end portion of the flap arm may comprise a first skirt and a distal end portion of the support arm may comprise a second skirt that engages the first skirt. When positioned in a gap, the skirted leaf seal may exert a force to urge the first flap arm towards the flap and to urge the wall arm and the support arm towards the structure to seal the gap.

The turboshaft engine for a rotorcraft includes a low pressure spool having a low pressure compressor and a low pressure turbine section, and a high pressure spool having a high pressure compressor and a high pressure turbine section. The spools are independently rotatable relative to one another. The low pressure compressor section includes a mixed flow rotor. A set of variable guide vanes (VGVs) are discposed upstream of each of the low pressure and high pressure compressors, the VGVs being configured to be independently operable relative to one another.