An axial flow turbine provided with a stage composed of a turbine nozzle and a turbine rotor blade arranged in an axial flow direction. Both end portions of a nozzle blade of the turbine nozzle are supported by a diaphragm inner ring and a diaphragm outer ring, and a flow passage is formed to have its diameter expanded from an upstream stage to a downstream stage. In such axial flow turbine, trailing edges at ends of the nozzle blade supported by the diaphragm inner ring and the diaphragm outer ring are curved as a curvature to an outlet side, and an intermediate portion between the trailing edges is formed to be straight.

Axial flow turbine

In the invention, propagating broad band and tonal acoustic components of noise characteristic of interaction of a turbomachine blade wake, produced by a turbomachine blade as the blade rotates, with a turbomachine component downstream of the rotating blade, are reduced. This is accomplished by injection of fluid into the blade wake through a port in the rotor blade. The mass flow rate of the fluid injected into the blade wake is selected to reduce the momentum deficit of the wake to correspondingly increase the time-mean velocity of the wake and decrease the turbulent velocity fluctuations of the wake. With this fluid injection, reduction of both propagating broad band and tonal acoustic components of noise produced by interaction of the blade wake with a turbomachine component downstream of the rotating blade is achieved. In a further noise reduction technique, boundary layer fluid is suctioned into the turbomachine blade through a suction port on the side of the blade that is characterized as the relatively low-pressure blade side. As with the fluid injection technique, the mass flow rate of the fluid suctioned into the blade is here selected to reduce the momentum deficit of the wake to correspondingly increase the time-mean velocity of the wake and decrease the turbulent velocity fluctuations of the wake; reduction of both propagating broad band and tonal acoustic components of noise produced by interaction of the blade wake with a turbomachine component downstream of the rotating blade is achieved with this suction technique. Blowing and suction techniques are also provided in the invention for reducing noise associated with the wake produced by fluid flow around a stationary blade upstream of a rotating turbomachine.

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Reduction of turbomachinery noise

A method enables a gas turbine engine (10) to be assembled. The method comprises forming at least one substantially elliptically-shaped opening (80) within a flange (72) extending from a fan disk (40), inserting a fastener (120) including a first body portion (122), a second body portion (124), and an anti-rotation stop (126) extending therebetween, at least partially through the at least one flange opening, and coupling the fastener to the flange such that the fastener stop is positioned within the at least one flange opening.

Methods and apparatus for assembling gas turbine engines

An article of manufacture having a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in a TABLE 1. Wherein X and Y are distances in inches which, when connected by smooth continuing arcs, define airfoil profile sections at each distance Z in inches. The profile sections at the Z distances being joined smoothly with one another to form a complete airfoil shape.

Airfoil shape for a compressor

A turbine stage includes a row of airfoils (14) joined to corresponding platforms (16) to define flow passages (30) therebetween. Each airfoil (14) includes opposite pressure and suction sides (20,22) and extends in chord between opposite leading and trailing edges (24,26). Each platform (16) includes a crescentic ramp (32) increasing in height from the leading and trailing edges (24,26) toward the midchord of the airfoil (14) along the pressure side (20) thereof.

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Crescentic ramp turbine stage

A rotor assembly (10) for a gas turbine engine (12) operates with reduced circumferential rim stress. The rotor assembly includes a rotor (14) including a plurality of rotor blades (26) extending radially outward from an annular rim (20). A root fillet (80) extends circumferentially around each blade between the blades and rim. The rim includes an outer surface (28) including a plurality of concave indentations (90) extending between adjacent rotor blades and forming a compound radius. Each indentation extends from a leading edge (40) of the rotor blades towards a trailing edge (42) of the rotor blades.

Method and apparatus for reducing rotor assembly circumferential rim stress

A self bleeding rotor blade and method of operation are disclosed for reducing boundary layer thickness for improved performance. The rotor blade includes an outer surface configured for pressurizing air flowable thereover with bleed apertures being disposed therein for bleeding a portion of boundary layer air from the outer surface during operation and thereby decreasing its thickness for improving aerodynamic performance of the blade.

Self bleeding rotor blade

A turbofan gas turbine engine (10) includes a forward fan section (33) with a row of fan rotor blades (32), a core engine (18), and a fan bypass duct (40) downstream of the forward fan section (33) and radially outwardly of the core engine (18). The forward fan section (33) has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes (35) downstream of the forward fan rotor blades (32). An exemplary embodiment of the engine includes an afterburner (130) downstream of the fan bypass duct (40) between the core engine (18) and an exhaust nozzle (68). The variable fan outlet guide vanes (35) are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5 - 4+. Struts (31) extend radially across a radially inwardly curved portion (131) of a flowpath (29) of the engine (10) between the forward fan section (33) and the core engine (18).

/pdf/turbofan-gas-turbine-engine-with-variable-fan-outlet-guide-56mglfgdej.pdf

Turbofan gas turbine engine with variable fan outlet guide vanes

A gas turbine engine rotor assembly including a rotor having a radially outer rim with an outer surface shaped to reduce circumferential rim stress concentration between each blade and the rim. Additionally, the shape of the outer surface directs air flow away from an interface between a blade and the rim to reduce aerodynamic performance losses between the rim and blades. In an exemplary embodiment, the outer surface of the rim has a concave shape between adjacent blades with apexes located at interfaces between the blades and the rim.

Reduced-stress compressor blisk flowpath

A compressor airfoil (12) includes pressure and suction sides (18,20) extending from root (22) to tip (24) and between leading and trailing edges (26,28). Transverse sections have respective chords and camber lines. Centers of gravity (34) of the sections are aligned along a bowed stacking axis either tangentially, axially, or both, for improving performance.

Mark Joseph Mielke

Papers

Method and apparatus for reducing rotor assembly circumferential rim stress

Self bleeding rotor blade

Turbofan gas turbine engine with variable fan outlet guide vanes

Reduced-stress compressor blisk flowpath

Bowed compressor airfoil