Abstract: An airfoil includes preformed first and second sides joinable together at a bond line extending between first and second opposite edges thereof. The first side includes a first extension having a proximal end forming a first end of the bond line, an intermediate section, and a distal end. The second side includes a second extension extending from the airfoil first edge which is fixedly joinable to the distal end of the first extension. The intermediate section of the first extension is spaced from the airfoil first edge to define therewith a working void so that pressure loading on the intermediate section is carried in part through the bond line first end for diffusion bonding thereof.

Abstract: A gas turbine engine turbine airfoil includes first and second opposite sidewalls joined together at leading and trailing edges and extending from a root to a tip thereof. The sidewalls have respective outer surfaces over which is flowable combustion gases during operation. The sidewalls are spaced apart to define an internal flow passage for receiving a cooling fluid. A plurality of ejection slots are arranged in a column through the first sidewall and have flow inlets for receiving cooling fluid from the internal flow passage and ejecting the fluid from respective flow outlets along the outer surface. At least some of the ejection slots are inclined at an acute ejection angle which varies in magnitude for preferably matching the respective inclination of combustion gas streamlines flowable over the airfoil surface.

Abstract: A method of detecting hydraulic leaks from a high pressure fuel hydraulic system is useful in systems where a pump, actuators, and hydraulic lines are filled with engine fuel at high pressure. The method comprises the steps of calculating pump flow based on a core engine RPM and a pump displacement, and calculating actuator fluid flow. System condition signals are then generated to indicate whether the core engine RPM is constant and whether the actuators are quiescent. A servo flow value is then provided, typically at predetermined system conditions, as indicated by the system condition signals, using the pump flow calculation and the actuator fluid flow calculation. Finally, leak flow is determined based on the pump flow calculation, the actuator fluid flow calculation, and the servo flow value, and the leak flow is responded to accordingly.

Abstract: An active liner for attenuating noise includes a rigid backplate supporting a piezoelectric panel. A pressure transducer is disposed in the panel for sensing acoustic pressure of noise being propagated against a face surface of the panel. A controller includes a predetermined schedule of acoustic impedance for controlling a displacement driver joined to the panel to effect a displacement velocity of the panel face surface for obtaining a predetermined acoustic impedance at the sensed acoustic pressure for attenuating noise.

Abstract: A gas turbine engine airfoil includes first and second sidewalls joined together at opposite leading and trailing edges and spaced apart from each other to define at least one internal flow channel for channeling cooling air therein. A plenum is defined by an inner surface of the first sidewall and by an internal wall adjoining the flow channel. A pair of injection holes extend through the internal wall to feed the cooling air into the plenum. A plurality of film cooling holes extend through the first sidewall in flow communication with the plenum for channeling the cooling air in a film along an outer surface of the first sidewall to effect film cooling. The injection holes are aligned to converge toward each other so that cooling air jets discharged therefrom collide with each other inside the plenum to reduce pressure thereof. This regulates the pressure across the film cooling holes to improve film cooling.

Abstract: A variable stator vane includes an airfoil with an integral outer trunnion having a seat extending integrally therefrom. A threaded stem extends from the seat and includes a coextensive alignment surface that cooperates with a complementary mounting hole in a lever arm which restrains rotation of the lever arm about the stem during assembly for ensuring a predetermined rotational orientation between the lever arm and the airfoil.

Abstract: A blade support includes first and second abutting disks, with the first disk having a plurality of axial dovetail slots at one end thereof, and a circumferential dovetail first half-slot at an opposite end thereof, with the second disk having a circumferential dovetail second half-slot therein. A plurality of rotor blades have axial dovetails disposed in respective ones of the axial dovetail slots, and circumferential dovetails disposed in part in each of the first and second half-slots. The first and second disks are retained together so that the first and second half-slots collectively support the circumferential dovetails.

Abstract: A blade containment system is disclosed which includes an annular casing positioned radially outward of the blades and in surrounding relationship therewith, the annular casing including a plurality of ribs on the outer radial surface thereof, wherein the ribs limit the propagation of cracks and holes formed in the annular casing.

Abstract: A turbine frame includes outer and inner coaxially disposed annular casings having a plurality of circumferentially spaced apart struts extending therebetween is provided with at least one and preferably two axially spaced apart polygonal stiffening rails, a forward rail and an aft rail, circumferentially disposed on the outer annular casing. The rails have at least a first section with a constant cross-sectional area normal to the casing in a circumferential direction around the outer casing, a linear centroid distribution of the cross-sections in the circumferential direction, and the centroids lie in a first plane P1 which is parallel to and spaced apart from a second plane P2 that is tangential to the outer casing mid-way between adjacent struts.

Abstract: The present invention provides a cooling apparatus with two spaced apart walls, one of which is a coolable wall, having a cooling flowpath between them wherein the cooling flowpath is converging in the direction of the cooling flow. In one embodiment the coolable wall is an afterburner cooling liner that includes a film cooling means on the hot side of the liner. Another embodiment provides a corrugated or wavy wall afterburner cooling liner wherein each wave includes a forward facing surface, from crest to trough of the wave in the direction of the hot gas flow, and an aft facing surface, from trough to crest. A high density pattern of multi-hole film cooling holes is disposed on the hotter of the two surfaces and a lower density pattern on the cooler one.

Abstract: A coolable airfoil for use in gas turbine engine component such as a turbine blade or vane is provided with a one-piece integrally formed double shell outer wall surrounding at least one radially extending cavity. The inner and the outer shells are integrally formed of the same material together with tying elements in the form of continuous ribs which space apart the shells, mechanically and thermally tie the shells together, and form convective cooling passages therebetween.

Abstract: A film starter structure for a combustor of a gas turbine engine which includes a plurality of circumferentially spaced, axially extending ribs formed on a radially inner surface of a forward section of an outer combustor liner adjacent a combustor dome. An annular ring overlays the ribs for defining a plurality of air passages. A support extends from the combustor dome and supports the outer liner about the dome. Compressor discharge air is introduced into the air passages and exits the air passages along the inner surface of the outer liner for establishing a cooling film barrier on the outer combustor liner surface. A spring seal between the combustor dome and the inner ring seats the dome within the ring and establishes a seal for preventing leakage air therebetween and allowing independent radial expansion of the liner and dome by compressing the spring seal.

Abstract: 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.

Abstract: A gas turbine engine fan assembly includes an equal number of rotor blades and stator vanes spaced axially therefrom. An annular duct surrounds the blades and vanes and has an inlet for receiving air and an outlet for discharging at least a portion of the air upon compression by the blades. The fan duct further includes a passive acoustic liner tuned for attenuating at least one harmonic noise tone generated by the blades, with a fundamental blade passing frequency noise tone being actively attenuated by a plurality of anti-noise sound transmitters disposed in the fan duct.

Abstract: An improved, highly stable blade-to-blade vibration damper configuration which provides substantially continuous blade vibration damping and sealing of an interplatform gap due to positional stability thereof. Disposed in a subplatform cavity, the damper is comprised of a generally triangular shaped body having a vertex thereof aligned with the interplatform gap. A primary damper load face abuts a first inclined platform load face and a secondary damper load face abuts a second inclined platform load face. Maintenance of sliding planar contact between primary and first load faces and sliding linear contact between secondary and second load faces is afforded by orienting inclined platform faces to have an included angle greater than that of the damper vertex and offsetting a damper center of gravity toward the primary load face. The damper may include one or more legs to orient the damper in the cavity and one or more extending tabs to discourage hot gas flow thereby.

Abstract: A modified inverter/converter unit electronically commutates a switched reluctance machine to provide multiple voltage levels for engine and aircraft applications. A set of power switching transistors apply an exciting current to windings in the switched reluctance machine to produce power at a first voltage level. Additional voltage levels may be provided by using the turns ratio from a plurality of transformers and the switching frequency from the power switching transistors. Alternatively, additional voltage levels may be provided by using windings of a plurality of transformers internal to the switched reluctance machine.

Abstract: A turbine disk cooling system for a gas turbine engine of a type having a compressor section including first and second disks connected by a seal and defining a compressor interstage volume, a turbine section including first and second stage disks connected by a seal and defining a turbine inner stage volume, and a compressor shaft interconnecting the compressor disks with the turbine disks including orifices located in the compressor seal for allowing air in the compressor section to enter the compressor interstage volume, and a radial inflow impeller for guiding the compressor air towards the compressor shaft. The impeller including a plurality of radially-extending conduits suspended in the compressor interstage volume, the conduits having a plurality of interior, radially-extending passages for conveying the compressor air from the orifice to the compressor shaft.

Abstract: A method is provided for making a two-piece hollow airfoil having a complex geometry. Two metal sheets are formed into initial shapes so as to have a mean camber and twist. A series of raised ribs is machined onto the external side of each of the two sheets. The two sheets are joined together and sealed to form an in-process assembly. The assembly is subjected to high temperature and pressure to diffusion bond the sheets together at selected points. The assembly then subjected to internal pressure at high temperature in order to inflate and superplastically deform the assembly to the desired shape. Excess material is machined off after the inflation step.

Abstract: A coupling assembly for fluid carrying tubes in a gas turbine engine include first and second fittings fixedly joined to respective ones of the tubes. The first and second fittings include respective first and second mating flanges which are joined together by a clamping band which is adjustable therearound. The first and second flanges include oppositely facing first and second flat faces, with the first flange having a counterbore extending inwardly from the first face, and the second flange having a pilot tube extending outwardly therefrom for being inserted into the counterbore. An annular seal is disposed between the first and second fittings for providing a leak-proof coupling upon clamping together of the two fittings by the clamping band.

Abstract: The present invention provides a method and an apparatus for selecting a valid signal from a plurality of redundant sensor signals wherein the sensor signals may include a plurality of measured and modelled signals. The invention comprises a circuit for generating a plurality of first pass/fail signals by performing a series of tests on the sensor signals. The invention further comprises circuitry for assigning a plurality of weighted values to each of the measured sensor signals according to the first and second pass/fail signals wherein the second pass/fail signals are initialized as pass signals. The invention further comprises of circuitry for summing the weighted values for each measured sensor signal and generating second pass/fail signals for each measured sensor signal. The invention also includes circuitry for assigning selection flags to each sensor signal according to the first and second pass/fail signals and circuitry for selecting the valid signal from the selection flags.