Abstract: A failsafe nozzle actuating system for an aircraft gas turbine engine axisymmetric vectoring exhaust nozzle has a vectoring ring operably linked to a plurality of pivotal flaps which are circumferentially disposed about a nozzle centerline and bounding an exhaust gas flowpath in the nozzle. The failsafe nozzle actuating system has at least two independently operable first and second vectoring actuating systems including first and second groups of actuators operably connected to the vectoring ring and first and second failsafe control means to control power to the first and second groups of actuators, respectively. The first group of vectoring actuators is interdigitated with the second group of second vectoring actuators around the nozzle. Either of the two groups of actuators are operable to actuate the nozzle when the other group is failsafed.

Abstract: A switch device for controlling at least one electrical circuit comprises a pushbutton movable between a pair of preselected positions for effecting the operation of the switch device, an indicator movable in the switch device toward a viewable position for effecting a visual indication of one of the preselected positions of the pushbutton, and a resilient cantilever associated with the pushbutton and the indicator operable generally for moving the indicator into its viewable position upon the movement of the pushbutton to its one preselected position. The pushbutton includes apparatus for driving the resilient cantilever to effect its operation in response to the movement of the pushbutton to its one preselected position.

Abstract: An active power line conditioner circuit having a series compensation system arrangement utilizes a transformer-coupled three-phase voltage-source inverter. A conventional metal oxide varistor (MOV) and bypass breaker combination are provided on the line side of the coupling transformer. A solid-state thyristor shorting ("crowbar") switch is provided on the secondary side of the coupling transformer across the outputs of the three-phase voltage-source inverter (VSI). The crowbar switch circuitry utilizes a diode bridge with a thyristor on the dc side of the bridge resulting in the simplification that only one active device need be gated. Crowbar switching logic activates the crowbar switch based on the exceeding of a threshold voltage measured at the dc power source link to the voltage-source inverter. A direct measure of dc source link voltage is employed to determine when to trigger the conduction of the crowbar thyristor switch.

Abstract: A gas turbine engine includes a compressor joined to a turbine by a core rotor, with a combustor disposed therebetween for receiving compressed air from the compressor and fuel through a valve for producing combustion gas discharged to the turbine. A speed sensor measures speed of the core rotor, and a pressure sensor measures pressure at an inlet to the compressor. A controller is operatively joined to the sensors and the fuel valve and is configured for limiting fuel flow to the combustor in response to core acceleration rate and compressor inlet pressure to limit transient temperature of the combustor discharge combustion gas.

Abstract: A combination motor starter and protector module is described. The base member, in one embodiment, forms a motor protector compartment and a motor starter compartment. The motor protector, in one form, is a bimetallic switch configured to be coupled between a power source and the motor windings. The switch includes a stationary contact and a movable contact. A bimetal element, responsive to current flow through the protector, controls movement of the movable contact. The starter, in one form, is a positive temperature coefficient resistor (PTCR) disk configured to be connected in series circuit with the motor start winding. The cover of the combination housing includes, in one form, an integral capacitor support arm and terminal openings for receiving blade terminals of a run capacitor. The terminal openings in the cover align with blade receiving receptacles coupled to the PTCR start circuit.

Abstract: The present invention provides coolable exhaust nozzle flap and seal assemblies having liners that are spaced inward and apart from their respective flap and seal cool walls, to form a cooling passage therebetween that converges in the axial downstream flow direction. One embodiment provides single wall multi-hole film cooled nozzle flap and seal liners particularly for use individually or in combination on convergent and divergent hollow flaps and seals for variable exhaust nozzles. Flap and seal coolable assemblies may be unitary structures that are integrally fabricated or formed such as by casting.

Abstract: An end frame assembly for an electric motor is described. In one embodiment, the assembly includes an endshield, a bearing, an oil wick, and an oil well cover. The oil well cover has at least one endshield engagement tang for aligning with and being secured within an oil well cover engagement opening in the endshield and at least one bearing alignment finger for assisting in maintaining the bearing oriented with respect to a rotor shaft.

Abstract: A combustor mount joins a mounting arm of a combustor to a conical nozzle support of a turbine nozzle. The mounting arm includes a conical mounting flange having first and second axially spaced apart radial lands and a plurality of circumferentially spaced apart outer holes. The nozzle support includes a conical seat having first and second axially spaced apart radial rabbets and a plurality of circumferentially spaced apart inner holes. The first and second lands are disposed on respective ones of the first and second rabbets, with the outer and inner holes being aligned. A plurality of fasteners extend through respective pairs of the aligned holes for clamping together the mounting flange to the seat to mount the combustor to the nozzle support.

Abstract: A method for nondestructive/noncontact detection of alpha case on a surface of a workpiece made of titanium or a titanium-based alloy. Infrared radiation is reflected off of a selected portion of the workpiece surface and sensed by a detector which may comprise a scanning infrared radiometer, an infrared camera, or a spot radiometer. The presence of any alpha case in the selected portion of the workpiece surface is detected by comparing the intensity of the reflected infrared radiation to a predetermined intensity known to be indicative of the absence of alpha case. An image of the reflected infrared radiation may be created and the step of detecting the presence of alpha case may include the step of comparing the intensity of the reflected infrared radiation within the image to the predetermined intensity. According to a preferred embodiment, a target may be disposed between the source of the infrared radiation and the workpiece surface so as to create a predetermined pattern within the image.

Abstract: An exhaust nozzle of a gas turbine engine effective for reducing the emission of infrared radiation and providing an extensive maneuvering capability. The nozzle preferably is of the two-dimensional type and includes an exhaust cowl with a generally rectangular cross-sectional exhaust opening and a plug within the downstream end of the cowl. The plug, which is preferably wedge-shaped, is pivotable about a transverse axis running through the aft portion of the plug by an appropriate means, for example, a cam or a screw jack mechanism. The nozzle can also include blocker doors and louvers for providing thrust reversal.

Abstract: A gas turbine engine includes a controller configured for controlling combustor lean flameout. The engine includes a compressor joined to a turbine by a core rotor, with a combustor disposed therebetween for receiving compressed air and fuel for generating combustion gas discharged to the turbine. The controller is configured for reducing fuel flow to the combustor in response to speed of the core rotor and pressure of compressed air entering the combustor to decelerate the core rotor while preventing lean flameout in the combustor.

Abstract: A gas turbine blade includes an airfoil having first and second sides and an internal passage extending longitudinally therebetween for channeling air to cool the airfoil. A plurality of longitudinally spaced apart primary turbulator ribs extend into the internal passage from at least one of the first and second sides. An auxiliary turbulator rib is spaced between adjacent ones of the primary ribs. The auxiliary rib has a height which is less than the height of the primary ribs for augmenting convective heat transfer enhancement with reduced pressure loss, and, therefore, reduced cooling air requirements.

Abstract: A turbine blade includes an airfoil having first and second opposite sides and an internal passage extending longitudinally therebetween for channeling air to cool the airfoil. A single restart turbulator rib is disposed in the passage adjacent to the inlet and has a first height e.sub.1 for obtaining a first convective heat transfer enhancement. A plurality of primary turbulator ribs are disposed downstream from the restart rib in the passage. The primary ribs include an initial primary rib having a second height e.sub.2 for obtaining a second convective heat transfer enhancement, with the initial primary rib being spaced longitudinally from the restart rib at a first spacing S.sub.1, and spaced longitudinally from a second primary rib at a second spacing S.sub.2. The first enhancement is less than the second enhancement to reduce overcooling of the airfoil between the restart and primary ribs.

Abstract: An afterburning, gas turbine aircraft engine with an annular duct for carrying bypass airflow is provided with a sliding valve type of rear Variable Area Bypass Injector (VABI) system. This rear VABI varies the direction and volume of the flow of bypass air into separate regions at an afterburning section of the engine. The system includes a sliding valve mounted in the bypass duct that is translated axially to open and close slots leading to core engine exhaust flow in the afterburning section. The unique structure of the injector system enables the axial translation of this sliding valve to simultaneously control bypass airflow into: first, a mixer just upstream of the afterburning section; second, a plurality of slots leading to the afterburning section; and third, an exhaust nozzle cooling liner that is cooled with the remaining portion of the bypass air.

Abstract: A turbine blade includes an airfoil having opposite first and second sides and an internal passage extending longitudinally therebetween. A plurality of turbulator ribs extend from the first side into the passage and have substantially identical configurations including first and second ends having a span axis extending therebetween, first and second sides having a width therebetween, and a base and a tip having a height e measured therebetween. The passage includes a height H for defining a rib-to-passage height ratio e/H. Adjacent ribs are spaced apart at a longitudinal spacing S for defining a rib spacing-to-height ratio S/e. The rib configuration varies along the span axis between the rib first and second ends for correspondingly varying at least one of the ratios e/H and S/e to effect a varying convective heat transfer enhancement along the rib span axis for increasing enhancement and reducing cooling airflow.

Abstract: A gas turbine engine turbine blade and method of manufacture includes an airfoil having pressure and suction sides joined together at leading and trailing edges. The airfoil further includes a supply channel for receiving compressed air, and has an elongate recess disposed in at least one of the pressure and suction sides which is separated from the supply channel by a partition. The partition includes a plurality of spaced apart flow metering holes disposed in flow communication with the supply channel. A transpiration strip is fixedly joined to the airfoil in the recess and spaced from the partition to define a plenum for receiving the compressed air from the metering holes. The transpiration strip is pervious for channeling the compressed air from the plenum in a blanket of film cooling boundary layer air therefrom.

Abstract: An apparatus for suppressing or attenuating acoustic pressure oscillations in a gas turbine engine combustor, the apparatus having a quarter wave resonator with a cavity closed at a first end and open at a second end and a characteristic length that reflects waves 180 degrees out of phase with the incoming waves and a viscous damper at the open end of the cavity. At least one resonating tube with a closed end and an open end and a single cavity therebetween, a damping plate with a plurality of apertures therethrough disposed across the open end, and a means for mounting the tube on the engine so that the damping plate is essentially flush with the wall. The apertures preferably have a total open area that is about 8% of an inclusive area of the open end and the tube may be cylindrical and the apertures circular.

Abstract: A heat shield for a gas turbine engine combustor of the type composed of multiple annular stages. The heat shield is particularly adapted for use in a middle stage disposed between radially inward and outward stages of a multistage combustor, and configured to form centerbodies that isolate the middle stage from the other stages of the combustor. The heat shield is composed of an annular array of single crystal superalloy segments. To achieve acceptable levels of durability for the superalloy segments, their primary and secondary crystal orientations are controlled to achieve a balance between the ability to withstand thermally-induced stresses and those stresses induced by high levels of acoustic energy, particularly those high levels attained as a result of a combustor operating with lean fuel/air ratios.

Abstract: A nozzle cooling system for selectively cooling longitudinally extending and circumferentially adjacent divergent exhaust flow confining elements bounding a hot exhaust gas flowpath in a divergent section of an aircraft gas turbine engine exhaust nozzle and providing pivoting capability for divergent flaps and seals in an axisymmetric vectoring nozzle. The apparatus includes axially adjacent forward and aft sections of at least one of the exhaust flow confining elements (typically referred to as flaps and seals), the adjacent forward and aft sections have forward and aft interior hot surfaces respectively, and mounting apparatus for mounting the aft section to the forward section in one of at least two positions.

Abstract: An air fuel mixer is disclosed having a mixing duct, a shroud surrounding the upstream end of the mixing duct in which a fuel manifold is provided in flow communication with a fuel supply and control means, a set of inner and outer counter-rotating swirlers adjacent the upstream end of the mixing duct for imparting swirl to an air stream, a hub separating the inner and outer annular swirlers to allow independent rotation of the air stream, and a centerbody located axially along and substantially the full length of the mixing duct. In order to inject one type of fuel into the mixing duct, fuel is supplied to the outer annular swirlers which include hollow vanes with internal cavities, wherein the internal cavities of the outer swirler vanes are in fluid communication with the fuel manifold in the shroud. The outer swirler vanes further include a plurality of fuel passages therethrough in flow communication with the internal cavities.