Abstract: A carbon seal contaminant barrier system for a gas turbine engine including a lip seal for wiping the surface of a rotating seal runner, and a baffle spaced from the rotating seal runner to prevent the impingement of the contaminants on the lip seal. The lip seal and the baffle are spaced axially and cooperate to minimize the contaminants passed to a carbon sealing system. The circumferential carbon sealing ring having a plurality of passages therethrough for delivering pressurized gas adjacent the carbon sealing ring. The pressurized gas being utilized to reduce the drag on the lip seal and to reduce the migration of contaminants onto the carbon seal. The barrier system being utilized to reduce the contamination of the carbon seal and prevent the inherent leakages associated therewith and the potential contamination of the environmental system of the aircraft.

Abstract: Disclosed is an integral single-cast multi wall structure including a very thin wall and a second thin wall. There is a passageway interposed between the pair of walls of the structure, and a high thermal conductivity member extends into said passageways and thermally couples the walls. The high thermal conductivity member increases the heat transfer between the walls of the structure. The present invention further includes a method for casting an integral structure having very thin walls that utilizes the high thermally conductive member in the casting process to hold the pattern and cores in alignment.

Abstract: The present invention relates generally to a low emission can-annular combustion system for an industrial gas turbine engine to satisfy increasingly stringent environmental requirements. The combustion system of the present invention employs a dual mode combustion technique to meet engine operability requirements and high power emission targets without the use of combustor diluent injection or post combustor exhaust treatment. A lean premix combustion mode is utilized to minimize primary zone combustion temperatures and limit the oxide of nitrogen production during high power engine operation. A pilot-starting auxiliary fueling system is utilized to augment the main premix fueling system. The lean premix combustion mode is enabled by a lean premix dome having a fixed axial swirler with radial fuel pathways connecting to a circumferential main fuel manifold for distributing the fuel more uniformly across the flow path.

Abstract: A self closing valve for use with an engine that prevents the loss of fluid from a transmission connected to the engine when a magnetic chip detector is removed from the transmission housing. The self closing valve and magnetic chip detector being integrated together to form a magnetic chip detection system that provides an indicating signal to the operator of an aircraft when magnetically attractable debris is detected in the transmission. The self closing valve includes a pair of valve doors that rotate about a pivot point so as to be moveable from a central region of a passageway within the transmission housing. Further, the valve does not extend substantially into the interior of the mechanical housing but is closeable to prevent loss of fluid from the interior of the mechanical housing when the magnetic chip detector is withdrawn from the passageway.

Abstract: A pressure signal synthesis method is provided to accommodate failure of a pressure sensor in a gas turbine engine. The pressure signal is synthesized from the torque produced by the engine, and further determined from the corrected speed of a gasifier rotor and power turbine for a free-turbine engine configuration. The synthesized pressure signal may include a correction factor which accounts for the deviation of the engine from a nominal characteristic. This correction factor is determined during engine operation and periodically updated to account for changes in the deviation.

Abstract: A torque signal synthesis method is provided to accommodate torque measurements for a gas turbine engine. The torque signal is synthesized from gas pressure sensed at an engine station. The synthesized torque signal may include a correction factor which accounts for the deviation of the engine from a nominal characteristic. This correction factor is determined during engine operation and periodically updated to account for changes in the deviation. The synthesized torque signal may further be determined from the corrected speed of a gasifier rotor and power turbine of a free turbine engine configuration.

Abstract: A thrust vectoring system comprising a working fluid source mounted to an aircraft, and a vectoring nozzle connected to the working fluid source which has an extendable conduit defining a passage from an inlet to an outlet. The passage is adjustable so that the direction of the working fluid exiting the outlet is different than the working fluid entering the inlet when the conduit of the vectoring nozzle is extended. This conduit provides a way to change the direction of working fluid exiting the nozzle and correspondingly change the thrust vector of the aircraft. A directing member such as a guide vane or door is mounted to the conduit adjacent the outlet to further direct the working fluid exiting the outlet. Directing members provide a way to refine the thrust vector without changing the extension of the segmented conduit. Another aspect of the present invention is to provide an adapter to connect the vectoring nozzle to a working fluid source with an annular outlet.

Abstract: The present invention contemplates a hybrid magnetic bearing thrust disk. In one embodiment the hydrid magnetic bearing thrust disk comprises a high magnetic permeable portion that is supported by a high specific strength circumferential ring. The high specific strength circumferential ring resisting the dynamic loads applied to the hydrid thrust disk.

Abstract: A high performance hybrid shaft for use in applications where high stiffness, high temperature capacity and lightweight are important. In one form of the present invention the hybrid shaft is formed of a titanium alloy outer tube having in it's interior a gamma titanium aluminide alloy powder metal that is metallurgically bonded to the outer tube. The gamma titanium aluminide alloy powder metal has a room temperature modulus of elasticity greater than the modulus of elasticity of the titanium alloy tube. The hybrid shaft has a modulus of elasticity greater than modulus of elasticity of the titanium alloy tube, and a density equivalent to that of the titanium alloy tube. The wear resistant capability of the shaft is increased at local regions by surface modification treatment such as plasma ion nitrating or by affixing at the ends of the tube a hardened steel fitting.

Abstract: A lightweight high temperature rotor blade attachment structure for use in a gas turbine engine. The lightweight high temperature rotor blade attachment lug being cast of a single crystal alloy and the lug is then bonded to a conventional nickel based wheel. A circular arc firtree is utilized to connect the insertable turbine blade between a pair of circumferentially spaced lugs that have been bonded to the turbine disk. In an alternate form of the present invention the attachment lug includes an internal cooling passage for receiving cooling fluid from a compressor. More particularly, the present invention discloses a single crystal attachment lug that is bonded to a powdered metal nickel alloy rotor disk and includes internal cooling passages, and in one form is designed for use with turbine blades that do not have a platform.

Abstract: A apparatus casting a turbine wheel of a metal alloy, wherein there is generated a columnar grain structure parallel to the leading and trailing edges of the vanes, by directional solidification of the metal from the central aperture in the wheel outward to the vane tips. A form with cavity to receive therein the molten metal has a thin walled core in the center, with the core wall outer surface in place to provide one wall of the cavity. A heat transfer medium in fluid form is circulated through the core, thereby cooling the poured metal by heat transfer from the inner ends of the vanes outward to the tips.

Abstract: A lightweight gas turbine rotor having a pair of high specific strength support ring members positioned fore and aft a center hub member. The unitary center hub member for carrying a plurality of airfoils that extend radially outward therefrom. The pair of high specific strength support ring members are connected to the blade carrying member at a location to compressively transmit the centrifugal force generated by the rotating rotor to a radially inward location on the support ring members. The support ring members being utilized to resist a majority of the centrifugal force generated by the components of the rotor. The center hub member and the pair of support ring members are made of different materials. More particularly the pair of support ring members are made of a metal matrix composite, and the center hub member when utilized in a compressor is formed of a high temperature titanium alloy, and the center hub member when utilized in a turbine is formed of a nickel alloy.

Abstract: An integrated system for controlling the positioning of a rotating rotor within a compressor to enhance the performance of a gas turbine engine. The rotor being attached to a rotating shaft that is coupled to the compressor housing by a magnetic bearing system. The magnetic bearings support and position the rotor within the high speed tubomachine. During operation of the compressor the magnetic bearings non-axially position the rotor relative to the compressor housing to provide compressor instability control. By non-axially displacing the rotor relative to the compressor housing there is a resulting local disturbance to the fluid flow field, which in turn serves as the disturbance to alter the dynamics of the aerodynamic system and displace the compressor surge line.

Abstract: The present invention relates to a method and apparatus for producing a cast structure. In one embodiment of the present invention an alloy casting mold has molten alloy injected therein to facilitate completely filling a part cavity within the mold. Further, an alloy charge pressure control device is utilized to reduce the charge pressure of the molten alloy during its injection into the mold cavity to minimize distortion and creep of the ceramic shell. In one form of the present invention the charge pressure control device removes excess alloy so as to reduce the head pressure of the molten alloy thereby eliminating the undesirable creep of the ceramic shell.

Abstract: Foreign object ingestion damage detection and accommodation system for a gas turbine engine system having a gas turbine engine with multiple rotating members, such as a twin spool configuration. System includes speed sensors for sensing the rotational speed of at least two rotating members. Sensors are coupled to a controller which detects damage by comparing the sensed speed of the second rotational member to an expected speed. Expected speed is determined from the sensed speed of the first rotating member using a known characteristic relationship between the the first and second rotating member speeds for the given gas turbine engine design. Thrust loss accommodation is triggered when damage is detected. Accommodation mode provides a synthesized primary thrust control feedback signal in lieu of the sensed signal for a damaged rotational member. Synthesized signal is derived from the sensed speed for the undamaged rotational member.

Abstract: A lightweight high temperature multiproperty rotor disk and method of manufacture for use in a gas turbine engine. The rotor disk of a nickel super alloy and having a plurality of lightweight high temperature single crystal blade attachment lugs bonded thereto. The single crystal high temperature rotor blade attachment lugs being cast in a substantially rectangular shape and bonded to the circumference of the disk. A method of manufacturing the rotor includes positioning the plurality of single crystal attachment lugs on a positioning ring that has locating nests formed thereon. Subsequently, the rotor disk is placed within the bonding ring and a restraining ring is placed around the entire subassembly. Upon subjecting the assembly to high temperature the rotor disk, having a coefficient of thermal expansion greater than the coefficient of thermal expansion of the restraining member, forces the components into a mating relationship.

Abstract: A fluid cooled seal arrangement for a gas turbine engine including a first sealing element coupled to a mechanical housing of the engine, and a second sealing element connected to a shaft rotatable within the housing. The first and second sealing elements are arranged radially adjacent to one another to form a rubbing interface therebetween. A lubrication system for delivering cooling fluid to the second sealing element through a passageway arranged along the rotating shaft. The cooling fluid is discharged through a plurality of openings formed in one end of the passageway. During normal operation of the engine the centrifugal force from the rotation of the shaft flings the oil radially outward to a channel formed on the underside of the second sealing element. The channel receives the cooling fluid therein, and allows for the escape of the cooling fluid onto the underside of the second sealing element to provide a uniform thickness of cooling fluid thereon.

Abstract: A method of casting a turbine wheel of a metal alloy, wherein there is generated a columnar grain structure parallel to the leading and trailing edges of the vanes, by directional solidification of the metal from the central aperture in the wheel outward to the vane tips. A form with cavity to receive therein the molten metal has a thin walled core in the center, with the core wall outer surface in place to provide one wall of the cavity. A heat transfer medium in fluid form is circulated through the core, thereby cooling the poured metal by heat transfer from the inner ends of the vanes outward to the tips.

Abstract: A gas turbine component that includes a very thin wall. The gas turbine component being of a single-piece, single-cast structure. In one form of the gas turbine component it is formed of a superalloy composition and is capable of withstanding gases impinging upon the walls at temperatures greater than 4000.degree. F.