Abstract: A turbine blade includes an airfoil and integral dovetail. The airfoil includes first and second sidewalls joined together at leading and trailing edges, and extending from a root to a tip plate. Twin ribs extend outwardly from the tip plate between the leading and trailing edges, and are spaced laterally apart to define an open-top tip channel therebetween. Each of the tip ribs has an airfoil profile for extracting energy from combustion gases flowable around the turbine blade.

Abstract: An air duct assembly for a gas turbine compressor rotor in a gas turbine engine is described. The rotor includes a compressor spool shaft and at least one stage disk, and the air duct assembly includes an elongate hollow cylindrical air duct configured to couple to a stage disk at a first end of the air duct. The second end of the air duct is configured to couple to the spool shaft. The second end of the air duct includes a plurality of lobes depending radially inward, a spool shaft insert configured to fit into an opening in the spool shaft, and a plurality of pins coupled to the spool shaft insert and configured to extend from the insert and to engage the lobes of the second end of the air duct.

Abstract: A swivel flange seal joint assembly which includes a tube having an integral, enlarged ferrule and swivel flange is described. The ferrule is enlarged and includes oversized fastener openings configured to allow circumferential alignment between the swivel flange and openings in a mating surface. The assembly also includes a gasket having openings, and the gasket is positioned between the ferrule and the mating surface so that a seal is formed between when the fasteners which extend through the flange, ferrule, gasket and mating surface openings are tightened.

Abstract: A system for cooling hot section components of a gas turbine engine. The cooling system includes a plurality of compressors, or compression train, and an intercooler disposed between each adjacent pair of compressors so as to achieve the desired pressure and temperature of the cooling air at reduced shaft power requirements. The first stage of compression may be provided by the booster, or low pressure compressor, of the engine, with the first intercooler receiving all of the air discharging from the booster. After exiting the first intercooler, a first portion of the booster discharge air is routed to the engine high pressure compressor and a second portion is routed to an inlet of the second compressor of the cooling air compression train. The compressed, cooled air exiting the last, downstream one of the compressors is used for cooling at least a first hot section component of the engine.

Abstract: A modulated flow transfer apparatus for transferring a fluid flow from a static element to a rotor of a gas turbine engine has an annular static inducer for accelerating the fluid flow in a substantially circumferential direction. The inducer has an annular row of identical first and second flow passages with first and second inlets respectively and outlets. First and second flow means direct first and second portions of the flow to the first and second flow passages, respectively. A valve is used for selectively modulating the second portion of the flow which together with a controller may be used for selectively preventing the second portion of flow from flowing through the second flow passages during a first cruise of engine operation and allowing substantially unrestricted flow therethrough during a takeoff mode of engine operation. The second flow means preferably includes an inducer manifold disposed between the valve and the second inlets.

Abstract: A gas turbine engine that includes a 2/3 stage intercooled booster compressor is described. In one embodiment, the engine includes a low pressure turbine and a booster compressor rotatable on a low pressure shaft. The engine further includes a high pressure compressor, a high pressure combustor, and a high pressure turbine rotatable on a high pressure (HP) shaft and forming the core engine. A low pressure combustor is located at the outlet of the high pressure turbine and a power turbine. The booster compressor includes first and second stage compressors, and air flow from the first stage compressor is supplied to a first intercooler, and air flow from the second stage compressor is supplied to a second intercooler. Airflow from the first intercooler is supplied to the inlet of the second stage compressor, and airflow from the second intercooler is split between being provided to the inlet of the high pressure compressor and a recuperator.

Abstract: A method of preventing water erosion and hot corrosion in a combustor of a gas turbine engine, wherein water is injected into said combustor for NOx abatement, which involves the step of applying a dense vertically cracked thermal barrier coating to certain components thereof The dense vertically cracked thermal barrier coating has a porosity of less than approximately 8% and a tensile strength in the range of approximately 4-7 ksi. The dense vertically cracked thermal barrier coating is applied to such combustor components so as to produce a segmented ceramic structure having macrocracks formed therein which are oriented substantially perpendicular to an interface of the combustor component and the segmented ceramic structure.

Abstract: A booster-compressor assembly for supercharging air into a core engine that powers propellers of a turboprop aircraft engine includes an asymmetric annular booster duct aft of the propellers and disposed about a centerline with at least one symmetric annular rotor section with a row of rotor blades disposed therein. The booster duct has a booster flowpath that includes a core flowpath to a core engine inlet and a bypass flowpath around the core engine inlet and the flowpaths circumscribed about the centerline and not symmetric with respect to each other. A low bypass flow rate means sets the airflow through the bypass flowpath such that a bypass flow rate per unit area through the bypass flowpath is substantially less than a core flow rate per unit area through the core flowpath.

Abstract: A gas turbine engine airfoil includes first and second sidewalls joined together at opposite leading and trailing edges, and extending longitudinally from a root to a tip. The sidewalls are spaced apart from each other to define in part first and second adjoining flow chambers extending longitudinally therein, and defined in additional part by corresponding first and second partitions disposed between the sidewalls. The second partition is common to both chambers, and both partitions include respective pluralities of first and second inlet holes sized to meter cooling air therethrough in series between the chambers.

Abstract: An exhaust nozzle for a gas turbine engine includes converging and diverging nozzles joined together at a throat and attached to a frame. An injection slot is disposed at the throat in flow communication with a transition duct for channeling injection air therethrough as controlled by an injection valve for fluidically varying throat area for exhaust gases discharged through the exhaust nozzle.

Abstract: Braze brackets utilized in connection with securing tubes and ducts to turbine engines are described. In one embodiment, the bracket includes a mounting plate having a curved braze surface. A plurality of tangs extend from the mounting plate. The specific dimensions for the braze surface and the tangs are selected depending upon the duct or tube to which the bracket is to be secured and the main bracket body to be used in connection with the bracket. In one embodiment, the curved braze surface has a semi-cylindrical geometric shape, and the tangs extend substantially radially from edges of the braze surface. The tangs are spaced along the edges of the braze surface.

Abstract: Precompressor and pre-booster water spray injection apparatus and methods are described. In an exemplary embodiment, a gas turbine engine suitable for use in connection with water spray injection includes a low pressure compressor, a high pressure compressor, and a combustor. The engine also includes a high pressure turbine, a low pressure turbine, and a power turbine. A water injection apparatus is provided for injecting water into an inlet of the high pressure compressor. The water spray injection apparatus is in flow communication with a water supply, and during engine operation, water is delivered from such supply through the injection apparatus to the inlet of the compressor.

Abstract: A blade retention system which allows a blade to be rotated about a blade stack axis by utilizing a cover, an anti-rotational key, and strap is described. The substantially cylindrical cover rotatably couples to a rotor disk opening using a thrust bearing. The cover includes a dovetail-load slot for receiving a rotor blade dovetail key. The anti-rotation key is positioned between the dovetail key and the dovetail-load slot to secured the blade to the cover. The strap holds the key in place and is clamped between the cover and the control mechanism.

Abstract: A gas turbine engine that includes a steam driven variable speed booster compressor is described. In one embodiment, the engine includes a low pressure turbine and a booster compressor rotatable on a low pressure shaft. The engine further includes a high pressure compressor, a high pressure combustor, and a high pressure turbine rotatable on a high pressure (HP) shaft and forming the core engine. The output of the low pressure compressor is supplied to an intercooler, and the output of the intercooler is supplied to the high pressure compressor. The engine further includes a power turbine downstream of the high pressure turbine, and the power turbine is coupled to a generator by a shaft. The output exhaust of the power turbine is supplied to an exhaust heat boiler, and steam output by the boiler is supplied to, and drives, the low pressure turbine. Steam from the boiler may also be supplied to the high pressure combustor and to the power turbine.

Abstract: An exhaust nozzle for a gas turbine engine includes a converging inlet duct disposed in flow communication with a diverging outlet duct at a throat therebetween. An ejection slot is disposed at the throat, and compressed air from the engine is selectively injected through the slot for fluidically varying flow area at the throat for exhaust gases from the engine.

Abstract: A gas turbine engine turbine blade squealer tip includes an airfoil tip cap having an airfoil shape and pressure and suction sides joined together at chordally spaced apart leading and trailing edges of the tip cap. The squealer tip further includes a plurality of squealer ribs extend outward from the tip cap between the leading and trailing edges and substantially parallel channels between the squealer ribs. The squealer ribs and channels may have rectangular cross-sections and may also include a trailing edge rib along a portion of the suction side including the trailing edge and/or a leading edge rib curved around an axially extending portion of the leading edge. The squealer ribs are preferably angled in an axially aft direction from the leading edge on the suction side towards the trailing edge on the pressure side. Channel ribs may be disposed between the squealer ribs and across the channels and may be arranged such that only one of the channel ribs is disposed across each of the channels.

Abstract: A turbine shroud includes a panel having a forward hook and an aft hook spaced therefrom. A primary cooling circuit extends through the panel adjacent the forward hook, and has a primary inlet for receiving primary air at a first pressure, and a primary outlet for discharging the primary air. A secondary cooling circuit extends through the panel adjacent the aft hook independently of the primary circuit. The secondary circuit includes a secondary inlet for receiving secondary air at a second pressure different than the first pressure, and a secondary outlet for discharging the secondary air. The dual cooled shroud accommodates differential gas pressure through the turbine.

Abstract: A blade assembly, which may have blisk for a gas turbine engine, includes an annular rim disposed about a rotor axis and a blade assembly disposed around the rim. The blade assembly has circumferentially disposed and radially extending inner and outer rows of inner and outer airfoils, respectively and each airfoil has axially spaced apart leading and trailing airfoil edges. An annular shroud is disposed between and connecting the inner and outer rows of inner and outer airfoils and has axially spaced apart annular leading and trailing shroud edges corresponding to the leading and trailing airfoil edges, respectively. An axially extending cavity is provided in each of the leading and trailing shroud edges for reducing stresses in leading and trailing airfoil edges, respectively and the corresponding airfoil edges are located near the cavities. The cavities preferably extend axially under the corresponding airfoil edges.

Abstract: A blocker and swirl inducer hole configuration for use in connection with a high pressure turbine is described. In one embodiment, the blocker holes are oriented to a 45-degree tangential angle with respect to the direction of rotation of the seal, which results in pre-swirling the air before being injected into the swirl cavity. In addition, the number of blocker holes is reduced by as much as 50% of the number of blocker holes used in the known CFM56 turbine. Further, rather than injecting the air into the first swirl cavity as is known, the air is injected into a second swirl cavity. The combined effect of orienting the holes to the 45-degree tangential angle with respect to the direction of rotation of the seal, locating the holes to open into the second swirl cavity, and reducing the flow area by about 50%, results in an increase in blocker hole pressure ratio. Increasing the blocker hole pressure ratio results in a higher hole exit velocity which maximizes the cavity inlet swirl.

Abstract: A flow regulator for controlling the flow of material from a container is disclosed, wherein the container includes a container outlet through which the material freely flows when the container outlet is not closed. The flow regulator includes a material passageway having an inlet. The inlet of the material passageway is moved relative to the container between a first position where the inlet of the material passageway is not aligned with the container outlet to prevent the free flow of material between the container and the material passageway and a second position where the inlet of the material passageway is aligned with the container outlet to permit the flow of material between the container and the material passageway. The regulator also includes a regulating flap, configured to substantially cover the container outlet, coupled between the container outlet and the inlet of the material passageway.