Abstract: A coating process and system suitable for use on components subjected to high temperatures. The coating system includes an overlay coating of predominantly B2 phase rhodium aluminide (RhAl) intermetallic compound containing about 25 to about 90 atomic percent rhodium, about 10 to about 60 atomic percent aluminum, optionally up to a combined total of about 25 atomic percent of one or more platinum group metals chosen from the group consisting of platinum, palladium, ruthenium, and iridium, and up to about 20 atomic percent of the base metal and alloying constituents of the substrate. The RhAl intermetallic coating may serve as an environmental coating, a diffusion barrier layer for an overlying environmental coating, or both, with or without an outer ceramic coating.

Abstract: Environmental barrier coatings having CMAS mitigation capability for silicon-containing components. In one embodiment, the barrier coating includes a bond coat layer comprising aluminide-alumina TGO; and an outer layer selected from the group consisting of AeAl2O19, AeHfO3, AeZrO3, ZnAl2O4, MgAl2O4, Ln4Al2O9, Lna4Ga2O9, Ln3Al5O12, Ln3Ga5O12, Ga2O3, HfO2, and LnPO4.

Abstract: A coolable borescope boss includes cooling passages extending through the boss and oriented for spraying cooling air into a hole extending through the boss. Centerlines of the cooling passages may intersect the a hole axis of the hole. The cooling passages may be cylindrical or open slots disposed through the boss. The boss may be on an arcuate gas turbine engine shroud segment circumscribed about an axial centerline axis. The segment may be part of an annular segmented turbine shroud having cylindrical shroud first and second sections and a conical shroud midsection therebetween and the segment having cylindrical segment first and second sections and a conical segment midsection therebetween. A hole exit of the hole being flush with the conical segment midsection. A borescope plug tip having a spherical tip chamfer may be used to seal against a conical boss chamfer of the boss.

Abstract: Methods for making near net shape airfoil metal leading edge protective strips including providing a high temperature additive manufacturing device; providing a tooling system having a mandrel; a metallic cladding applied to the mandrel; and at least one cooling channel associated with the mandrel applying a metallic deposit to the mandrel having the metallic cladding using the high temperature additive manufacturing device; and concurrently removing heat from the mandrel using the at least one cooling channel to produce the near net shape airfoil metal leading edge protective strip.

Abstract: Methods for making a self-conforming non-crimp fabric involving tailoring at least a first parameter to anchor the fabric and at least a second parameter to provide conformability of the fabric, the first and second parameters selected from stitch type, stitch spacing, stitch density, stitch material, stitch weight, stitch tension, and combinations of the same.

Abstract: Methods for making a reinforced refractory crucible for melting titanium alloys including providing a form, applying a facecoat to the form, the facecoat having at least one facecoat layer, applying a backing about the facecoat, the backing having at least one backing layer, applying at least one reinforcing element to at least a portion of the facecoat layer, the backing layer, or a combination thereof where the reinforcing element includes at least one composition selected from ceramic compositions, metallic compositions, and combinations thereof.

Abstract: A support frame includes a rail engaging a hook of a composite article having plys. The rail included a rail contact surface generally conformal to and contacting a hook contact surface of the hook. The rail and hook contact surfaces being substantially normal to the plys beneath the hook contact surface. One embodiment of the article is a composite nozzle segment including one or more airfoils extending radially between arcuate radially outer and inner band segments having plys curved about a centerline axis and the rail engages a hook of the radially inner band segment. The hook and the rail may be straight or arcuate. The frame includes a central body extending axially aftwardly from the rail to an aft frame flange. A frame pin may be mounted on the frame, engage the inner band segment or one of the airfoils, and may extend into a cavity in the airfoil.

Abstract: A composite nozzle segment includes one or more airfoils extending radially between arcuate radially outer and inner band segments having band plies curved about a centerline axis, an outer chordal seal line on an outer aft flange of the outer band segment, and thickened areas in corners of the outer aft flange along pressure and suction side edges of the outer band segment. The thickened areas may be thickest at the pressure and suction side edges and thinnest near a middle of the outer band segment. The thickened areas taper off from an aft end of the thickened area towards a forward flange of the outer band segment. Insert plies may be disposed between some of the band plies within the thickened areas may be grouped together in a discrete group or be interspersed with some of the band plies. The insert plies may have triangular shapes.

Abstract: A fluoride ion cleaning method includes generating hydrogen fluoride (HF) gas in-situ in a cleaning retort; contacting a part in need of cleaning with the generated HF gas; scrubbing an initial effluent stream in-situ to substantially remove residual HF gas therefrom; and passing the scrubbed effluent gas stream out of the cleaning retort. In an exemplary method, a liquid or gaseous halogenated feedstock is introduced into a cleaning retort; hydrogen gas is introduced into the cleaning retort, HF gas is generated by a reaction of the feedstock with hydrogen gas at a sufficient temperature. In an exemplary method, only HF gas generated in-situ or reconstituted in-situ is utilized in the cleaning process.

Abstract: Wear-resistant coating systems suitable for protecting surfaces subjected to contact wear at high temperatures, such as surfaces of an assembly comprising high-temperature components of gas turbine engines. The components have surfaces in wear contact with each other. One of the surfaces has a wear-resistant coating system thereon so as to be in wear contact with the surface of the other component. The wear-resistant coating system contains alternating layers of TiAlN and CrN.

Abstract: A gas turbine engine annular turbine casing having an annular shell, axially spaced apart forward and aft flanges extending radially outwardly from the shell, forward and aft case hooks depending radially inwardly from the annular shell, and an axially curved surface at an outer diameter of the aft flange. The axially curved surface may be a semi-spherical surface. The forward and aft case hooks may be located axially near or at the forward and aft flanges respectively. A circular row of holes may be axially disposed through the aft flange circumscribing the central axis and radially located between the outer diameter of the aft flange and the annular shell. An annular manifold spaced radially outwardly of the shell forming an annular space between the manifold and the shell and having impingement holes disposed through the manifold may be used for impinging cooling air on the axially curved surface.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: A durable blade, a method of manufacturing it and a method of repairing blades are described and claimed. Durable blade includes an airfoil having a pressure side and a suction side, a midspan shroud located on the airfoil, at least one recess on the midspan shroud and a wear pad attached to the recess of the midspan shroud.

Abstract: A gas turbine engine booster includes one or more rotatable booster stages having booster blades extending radially inwardly from a rotatable drum and one or more non-rotatable vane stages having booster vanes extending radially outwardly from a non-rotatable shell. The booster stages may be interdigitated with the vane stages. The booster may be co-rotatable or counter-rotatable with respect to a fan stage of an aircraft gas turbine engine. The booster may be driven by a single turbine or one of counter-rotatable turbines or though a gearbox by these turbines. The booster blades and the booster vanes extend across a core engine inlet duct having an entrance downstream of the first fan stage. A fan section with the booster may have counter-rotatable first and second fan stages with fan blades of the second fan stages connected to and mounted radially outwardly of the rotatable drum.

Abstract: A method of monitoring engine performance parameters of a gas turbine engine during its operation. The method includes sensing the performance parameters and generating analog sensor outputs, producing digital data by conditioning the analog sensor outputs with at least one hub unit that is mounted sufficiently close to the engine to be subjected to a first temperature in excess of 125° C., receiving the digital data from the hub unit with a collector unit subjected to a second temperature of less than the first temperature, receiving the digital data from the collector unit with a distributor computer unit subjected to a third temperature of less than the second temperature, and processing the digital data with the distributor computer unit to assess the engine performance parameters of the engine. The conditioning step is performed with a control circuit board and at least one signal conditioning circuit board within the hub unit.

Abstract: A vane frame for a turbomachine and a method for minimizing the weight of a vane frame. The vane frame includes an inner shroud made up of a plurality of inner shroud segments, an outer shroud circumscribing the inner shroud and made up of a plurality of outer shroud segments, and guide vanes structurally interconnecting the inner and outer shrouds. The guide vanes include a plurality of first guide vanes between and connecting first pairs of the inner and outer shroud segments, and a plurality of second guide vanes between and connecting second pairs of the inner and outer shroud segments. The first and second guide vanes are formed of different first and second materials, respectively, with the first material having lower strength, modulus, and/or density than the second material. The structural interconnection between the inner and outer shrouds is dominated by the second guide vanes.

Abstract: An aircraft gas turbine engine exhaust nozzle basesheet includes longitudinally extending plurality of basesheet segments. Each of the basesheet segments includes a panel body between segment leading and trailing edges and slidable sealing joints with slidingly un-restrained center surfaces between adjacent segment leading and trailing edges. Segmented first and second basesheet side edges first and second segment side edges of the basesheet segments respectively. Slidably sealingly engaged overlapping flanges at the segment leading and trailing edges include tacked together transversely spaced apart first and second distal ends of the overlapping flanges. Leading and trailing edge ribs supporting the overlapping flanges are clipped together with longitudinally spaced apart and transversely extending forward and aft slits in retainers.

Abstract: A gas turbine engine centrifugal compressor axial forward thrust apparatus bleeds impeller tip aft bleed flow from between an annular centrifugal compressor impeller of a high pressure rotor and a diffuser directly downstream of the impeller. The apparatus then uses the aft bleed flow to pressurize an annular cavity extending radially between an inner combustor casing and the rotor and extending axially between forward and aft thrust balance seals. Forward and aft thrust balance lands are in sealing engagement with the forward and aft thrust balance seals on the high pressure rotor respectively. An annular stator plenum in fluid communication with the annular cavity is bounded in part by a forward end wall having conical diffusion holes therethrough which may be axially or circumferentially or axially and circumferentially angled. The forward thrust balance seal may be on an aft conical arm of the impeller.

Abstract: A process and apparatus for producing perforated composite structures, such as acoustic skins suitable for aircraft engine nacelle and duct components. The process includes placing a mat member, a non-impregnated fabric member, and a resin film on a tool surface so that pins disposed on the mat member project through the fabric member and resin film to define holes therein. The fabric member is between the mat member and resin film, and the fabric member and resin film define a stack that conforms to the mat member and tool surface. A caul member is then placed on the stack so that apertures in the caul member are penetrated by the pins. The stack is heated to melt the resin film and cause molten resin to infuse the fabric member and yield a resin-infused fabric stack, after which the molten resin within the resin-infused fabric stack is at least partially cured.

Abstract: A method and system adjusts blade tip clearance between rotating aircraft gas turbine engine blade tips and a surrounding shroud in anticipation of and before an engine command that changes an engine rotational speed. The method may include determining when to begin adjusting the tip clearance by expanding or contracting the shroud before the engine command and may be based on monitored aircraft and/or aircraft crew data indicative of the engine. The aircraft and/or aircraft crew data may include communications between aircraft crew and air traffic control authorities or air traffic control surrogates. Determining when to begin adjusting the tip clearance may include using learning algorithms which may use the aircraft gas turbine engine's operating experience and/or operating experience of other jet engines on an aircraft containing the aircraft gas turbine engine and/or on other aircraft.