Abstract: A heatshielded article includes a support 18 and at least one heatshield 20 secured adjacent to the support. The heatshield includes a shield portion 28 spaced from the support. The shield portion includes a hot side 30 and an uncoated cold side 32. A projection projects from an origin 36 at the shield portion to a terminus 38 remote from the shield portion. The terminus includes a protective coating 64 along at least a portion of its length.

Abstract: A vane assembly 10 suitable for a turbine engine features a refractory vane 12 with an internal cavity 20 and a pair of flexible metallic baffles 26 extending into the cavity from spanwisely opposite ends of the vane. A rigid fastener 48, such as a nut and bolt assembly applies a tensile load to the baffles. The tensile load is reacted out as a compressive load applied to the vane. In another embodiment, the baffle is relatively rigid but the fastener is flexible. The compressive loading exerted on the vane counteracts the brittleness customarily exhibited by refractory materials and imparts damage tolerance to the vane. The arrangement also allows the use of a metal baffle that can be easily secured to the vane and dispenses with any need for a potentially troublesome seal between the baffles and the spanwise extremities of the vane.

Abstract: A bladed rotor includes a hub 12 with bayonet hooks 34, 36, a bayonet ring 64 with bayonet projections 66, 68 that engage the hooks, and a load transfer element that occupies an annulus 38 defined by the hooks. Ideally, the load transfer element is a substantially circumferentially continuous snap ring 60. If a blade separation event or other abnormality exerts an excessive axial load on a blade, the snap ring 60 safely distributes that load to the bayonet hooks 34, 36 to prevent the blade from severing the snap ring and being ejected axially from its slot.

Abstract: The invention is a film cooled article such as a turbine engine blade or vane, having a wall with a hot surface 26 to be film cooled. The hot surface 26 includes a depression 48 featuring a descending flank 52 and an ascending flank 54. Coolant holes 60, which penetrate through the wall, have discharge openings residing on the ascending flank 54. During operation, the depression locally over-accelerates a primary fluid stream F flowing over the ascending flank while coolant jets 70 concurrently issue from the discharge openings. The local over-acceleration of the primary fluid deflects the jets onto the hot surface and spatially constrains the jets thus encouraging them to spread out laterally and coalesce into a laterally continuous, protective coolant film. In one embodiment, the depression 48 is a trough 50. In another embodiment, the depression is a dimple 72.

Abstract: A vane cluster for a turbine engine compressor or turbine includes a shroud 12 with a nonlinear slot 26 extending therethrough to divide the shroud into thermally independent shroud segments 24. The slot is bordered by matching nonlinear surfaces 28 that are easy and inexpensive to produce with conventional wire EDM equipment. The nonlinear profile of the slots effectively resists fluid leakage.

Abstract: Rotor blades 40 for a bladed rotor feature a chamfered attachment 44 that improves the energy absorption capability of a snap ring 60 used as one component of a blade axial retention system. The chamfered attachment plastically deforms the snap ring rather than shearing through it in response to abnormally high forces exerted on the blade.

Abstract: A combustor for a gas turbine engine includes inner and outer liners with a row 112, 114 of dilution air holes penetrating through each liner. The row 114 of holes in the outer liner comprise at least a set of large size, major outer holes 116 and may also include a set of smaller size minor outer holes 118 circumferentially intermediate neighboring pairs of the major outer holes. The row 112 of holes in the inner liner include dilution air holes circumferentially offset from the major outer holes and may also include a set of minor holes 122 circumferentially intermediate major inner holes 120. The major and minor holes admit respective major and minor jets of dilution air into the combustor. The unique distribution of major and minor holes and the corresponding major and minor dilution air jets helps to minimize NOx emissions and regulates the spatial temperature profile of the exhaust gases discharged from the combustor.

Abstract: A variable geometry exhaust nozzle 10 for a turbine engine includes convergent and divergent flaps 12, 18 that circumscribe a gaspath 26 and define convergent and divergent nozzle sections 30, 32 with a throat 34 therebetween. A projection 56, which resides on the divergent flaps, extends radially inwardly from the nozzle. The nozzle also includes a coolant flowpath comprising an interior space 44 in the nozzle, an intake 58 for admitting coolant C into the interior space, and a coolant outlet 60 aft of the intake for discharging the coolant from the interior space. The intake resides forward of the throat. During operation, a coolant film flows along the radially inner surface of the nozzle. The projection encourages a portion of the coolant film to enter and flow through the the coolant flowpath to convectively cool the nozzle.

Abstract: A fastener for securing a composite panel 14 to a noncomposite support 12 includes a composite stud 22 with a notched shank 26, and a collar 36 with an axis 38 and circumferentially extending ribs 56. When assembled, the ribs 56 and notches 28 engage each other to resist axial translation between the stud and the collar. In one embodiment, a spring 66 urges the rib into contact with the notch to tension the stud and clamp the panel to its support. In a second embodiment, the collar 36a has external threads. A nut 76 engages the threads to tension the stud and clamp the panel to its support. The spring 66 is optional in the second embodiment. Because the composite stud is susceptible to damage if exposed to excessive torque, both embodiments include features to minimize torque transfer to the stud during assembly and disassembly.

Abstract: A bladed rotor features a tiered interface between each blade 40 and its respective slot 16 in a rotor hub 12. Ideally the interface is a tiered spacer 58 that occupies the hub slot radially inboard of the blade attachment 44. The spacer ensures a tight fit to resist windmilling induced wear. The tiered character of the spacer reduces the risk of damage during blade installation and removal. The spacer also helps to transmit axial loads to a snap ring, which is one component of a blade axial retention system, during a blade separation event.

Abstract: A fuel injector 20 for a combustor can 18 includes a pressure atomizing core nozzle and an airblast secondary injector. The airblast portion of the injector includes inner and outer air passages 98, 138 for injecting coannular, coswirling streams of inner and outer air into the combustor can. The injector also includes an air distribution baffle 154 that extends radially across the inner air passage 98 to divide the inner air stream into an annular substream AA and a plurality of air jets AJ.

Abstract: An apparatus for inspecting a selected target region in an interior cavity of a turbine engine rotor includes independent sources of ultraviolet and visible light for illuminating the selected target region, an arm having a working end translatable in a principal direction so that the working end is insertable into the rotor interior cavity, a primary camera mounted at the working end of the arm for capturing an image of the selected target region, a video monitor, and means for conveying the camera image from the primary camera to the video monitor. Ideally, the arm is also translatable in a secondary direction to facilitate positioning of the camera relative to the rotor. Suitable light guides convey the ultraviolet and visible light from their respective sources to the working end of the arm. A remote camera control, which is part of the camera electronics, allows an inspector to remotely focus the camera.

Abstract: An axial or centrifugal flow compressor having arrays of blades (16) extending across a working medium flowpath (18) includes a casing treatment for enhancing the compressor's fluid dynamic stability. The casing treatment features a circumferentially extending compartment (62), typically comprising a voluminous pressure compensation chamber (64) and a single passage (66) circumferentially coextensive with the chamber, for establishing fluid communication between the chamber and the flowpath. The voluminous character of the compartment attenuates the circumferential pressure difference across the tips of heavily loaded compressor blades (16), making the compressor less susceptible to tip vortex induced instabilities. In one embodiment of the invention, a passage (66) is oriented so that any fluid discharged from the passage enters the flowpath with a streamwise directional component.

Abstract: A combustor for a gas turbine engine includes inner and outer liners with a row 112, 114 of dilution air holes penetrating through each liner. The row 114 of holes in the outer liner comprise at least a set of large size, major outer holes 116 and may also include a set of smaller size minor outer holes 118 circumferentially intermediate neighboring pairs of the major outer holes. The row 112 of holes in the inner liner include dilution air holes circumferentially offset from the major outer holes and may also include a set of minor holes 122 circumferentially intermediate major inner holes 120. The major and minor holes admit respective major and minor jets of dilution air into the combustor. The unique distribution of major and minor holes and the corresponding major and minor dilution air jets helps to minimize NOx emissions and regulates the spatial temperature profile of the exhaust gases discharged from the combustor.

Abstract: A test system for testing the wiring configuration of a programming plug 10 for a gas turbine engine control unit 16 includes an array of multiplexers 28. The multiplexers concurrently acquiring one data bit from a prescribed data pin in each of several groups of data pins projecting from the plug. A computer operating under the authority of an executable computer program produces an incrementable selection signal to successively prescribe the individual data pins from which data is to be acquired. The system also includes standards against which the condition or validity of the wiring configuration is assessed. A display system, such as a video monitor reports the condition of the programming plug.

Abstract: The invention is a film cooled article such as a turbine engine blade or vane, having a wall with a hot surface 26 to be film cooled. The hot surface 26 includes a depression 48 featuring a descending flank 52 and an ascending flank 54. Coolant holes 60, which penetrate through the wall, have discharge openings residing on the ascending flank 54. During operation, the depression locally over-accelerates a primary fluid stream F flowing over the ascending flank while coolant jets 70 concurrently issue from the discharge openings. The local over-acceleration of the primary fluid deflects the jets onto the hot surface and spatially constrains the jets thus encouraging them to spread out laterally and coalesce into a laterally continuous, protective coolant film. In one embodiment, the depression 48 is a trough 50. In another embodiment, the depression is a dimple 72.

Abstract: A tangential entry premixing fuel injector (10) for a gas turbine engine combustor includes a pair of offset scrolls (18) whose ends define a pair of entry slots (36) for admitting primary combustion air tangentially into a mixing chamber (28) bounded by the scrolls (18) and by longitudinally spaced endplates (14, 16). An array of fuel injection passages (42) extends along the length of the slots. The passage array is configured to inject a primary fuel nonuniformly along the length of the air entry slots and to control the fuel penetration depth d in proportion to slot height R. The injector also includes a flame disgorging centerbody (48) having a bluff tip (54) longitudinally aligned with the injector's discharge plane (22) and a secondary fuel conduit (80) extending through the centerbody for discharging a secondary combustible fluid, preferably gaseous fuel, through a series of fuel discharge openings (84) in the tip (54).

Abstract: The invention is a method for allocating shroud or airseal segments among various positions in a turbomachinery case when the segments to be allocated differ in radial dimension or thickness and when the requirement for segment thickness varies around the circumference of the case. According to the inventive method, segment thicknesses are preliminarily assigned to positions on the case without regard for whether or not the thickness of each assigned segment satisfies the thickness requirement of its assigned position. Each thickness is then compared to the requirement of its assigned position and thicknesses that fail to satisfy the minimum thickness requirement of their assigned positions are consigned to a pool of noncompliant thickness values, thereby vacating zero or more positions Members of the pool are then systematically evaluated for suitability in the vacated positions.

Abstract: A liner for a gas turbine engine is provided that includes a first liner section and a second liner section. The first liner section includes a first flange having a first contact surface. The second liner section includes a second flange having a second contact surface and a plurality of apertures. The first and second flanges axially overlap one another, and in a circumferential liner the second flange is disposed radially outside of the first flange. A channel is formed by the two liner sections that is open to the core gas path. In a first position, the first flange axially overlaps the second flange by a first distance and the apertures are misaligned with the first flange and disposed within the channel. Cooling air entering apertures within the second flange subsequently passes into the channel. In a second position, the first flange axially overlaps the second flange by a second distance.

Abstract: A fixture for selectively masking a turbine blade 60 includes a locator 10 with a separable receptacle 40 having portals 50. Guide bars 18 extend from the locator for guiding a pair of shield carriers 20 between deployed and retracted positions. Each shield carrier has a shield 26 projecting therefrom. In use, a turbine blade 60, whose root 70 includes a fir tree attachment 72 and a damper pocket 74, is mounted on the fixture so that the receptacle embraces the blade root. The shield carriers are translated along the guide bars until the shields penetrate through the portals and into the receptacle thus segregating the attachment 72 from the damper pocket 74. Masking powder 84 is then compressed into the receptacle to envelop the attachment while leaving the damper pocket unmasked.