Abstract: The present invention relates to detectors used in X-ray tomographic imaging. The invention describes a multi-element detector array which detects ionization events in a xenon dielectric, and also describes a pressure vessel for containment of the xenon and detector.

Abstract: A gas turbine including at least a compressor, a combustor, and a turbine is constructed to operate at a preferred thermal efficiency in predetermined compressor and turbine flow pressure ratios. A fluid, such as steam, for example produced by waste heat and pressurized as water, and characterized as having a higher specific heat at constant pressure than effluent from the combustor is introduced into such effluent to provide a turbine operating medium of improved potential to transfer energy downstream of the combustor. Such injection provides effective variable geometry to the system. This injection system maintains such pressure flow ratios substantially independent of engine power output.

Abstract: A radial lip of a high temperature combustor liner is mechanically locked in a radially directed capture slot in a supporting shell of a combustor. In one embodiment, the capture slot is formed at abutting edges of shell sections which are joined by a weld bead. The weld bead is accessible for grinding off to provide access to the liner for replacement. In embodiments in which a plurality of liner sections are employed, a downstream end of a liner section overlaps and shields an upstream end of an adjacent liner section including the radial lip thereof to protect the radial lip and capture slot from temperatures in the combustion zone and to channel a sheet flow of film cooling air along an inner surface of the adjacent liner. Positioning bosses may be included between adjacent liner sections for centering.

Abstract: A propeller engine system with means for generating electric power within a rotatable hub is disclosed. The means include a shaft extending into the hub so that the hub and shaft are differentially rotatable. Magnetic means are fixed to the shaft and winding means are fixed to the hub so that either rotation of the rotor shaft or hub induces an electric current in the winding means.

Abstract: A combustion chamber for use in gas turbine engines is provided with a liner formed of a high temperature material. The liner includes a plurality of panels of material mounted by means of a slideable, frictional mounting arrangement upon a high strength structural frame. As a result of this mounting arrangement, the liner is substantially isolated from structural forces associated with the combustion chamber, while the frame is substantially isolated from thermal stresses associated with the liner. Means are provided for positioning and securing individual panel members axially relative to the frame. The panels may be continuous annular bodies, or may be circumferentially segmented. In the latter case, means are provided for mounting individual panels in a slideable, frictional cooperation with laterally adjacent panels, as well as for sealing the abutting junctions. The individual liner panels may be easily removed for repair or replacement without disassembling the frame and associated components.

Abstract: An improved seal cooling apparatus is provided for use in a gas turbine engine. In a particular embodiment, this apparatus includes means for deriving conditioning air from air discharged from the compressor diffuser and directing this air onto the seal stator to improve its thermal response. The apparatus also includes means to inject a portion of the conditioning air into a cavity forward of the seal to purge the region and prevent zero airflow conditions during engine operation for the purpose of discouraging overheating of a portion of the compressor rotor. A portion of the conditioning air from the cavity is subsequently directed to flow through and thereby cool the seal.

Abstract: The present invention comprises a cutting tool having a cutting tool insert which may be automatically rotationally indexed. The cutting tool includes a shank and an indexable cutting tool insert rotatably connected to the shank. The insert includes a plurality of tips and a side surface therebetween. Indexing means including an index member slidably mounted to the shank are also provided. The index member includes a locking surface and a cam lobe. The indexing means is effective for rotating the insert upon extension of the index member so that the cam lobe pushingly engages the insert, and locking the insert in a stationary cutting position upon retraction of the index member so that the locking surface is securely positioned against the insert side surface. In an exemplary embodiment of the invention, the index member comprises a slider which is translatable only in a direction parallel to a longitudinal axis thereof.

Abstract: An energy recovery system is provided for an aircraft gas turbine engine of the type in which some of the pneumatic energy developed by the engine is made available to support systems such as an environmental control system. In one such energy recovery system, some of the pneumatic energy made available to but not utilized by the support system is utilized to heat the engine fuel immediately prior to the consumption of the fuel by the engine. Some of the recovered energy may also be utilized to heat the fuel in the fuel tanks. Provision is made for multi-engine applications wherein energy recovered from one engine may be utilized by another one of the engines or systems associated therewith.

Abstract: A device is provided for efficiently directing nonrotating cooling air into a rotating turbine rotor. The device employs a nozzle to accelerate the cooling air in the direction of rotor rotation. A diffuser-deswirler then directs this air, with curved and expanding flow passages, into corresponding holes in the turbine rotor. With these elements, the device directs the cooling air into the rotating rotor section without significant pressure losses and with a lower resultant cooling air temperature.

Abstract: In one form of the present invention, a plurality of serovalves are connected to a common manifold. The manifold transmits fluid pressure from the servovalves to a modulator piston which controls the fluid pressure applied to a hydraulic actuator piston. The servovalves are designed such that, if the fluid pressure provided by any one of them to the manifold falls below a threshold, then the servovalve disconnects itself from the manifold, allowing control of the modulator piston to be assumed by the remaining, functioning servovalves. The present invention can be used in control surface actuators of short takeoff and landing (STOL) aircraft.

Abstract: An open-ended acoustic impedance tube is abutted against a material having a known acoustic impedance and a standing wave pattern is established in the tube. A first apparent impedance of the material is derived based on the standing wave pattern. A correction factor is computed based on the known impedance and the first apparent impedance. The open-ended impedance tube is then abutted against a sample material and a second apparent impedance is derived. The actual impedance of the sample is inferred from the second apparent impedance and the correction factor.

Abstract: A blade containment structure employs a two-layer honeycomb region radially outward of a fan blade rub strip. The two layers are separated by a septum and each layer contributes independently to strength and stiffness of the structure. A Kevlar blanket radially outward of the honeycomb region retains blade fragments which may be broken loose by ingestion of large objects such as, for example, birds. The radially inner honeycomb region is deep enough to position the septum out of the orbit of blade tips in an engine made unbalanced by loss of one or more fan blades. The septum and outer honeycomb region retains sufficient strength in the structure for supporting forward components.

Abstract: A swirler for a gas turbine engine combustor is disclosed for simultaneously controlling combustor flow rate, swirl angle, residence time and fuel-air ratio to provide three regimes of operation. A first regime is provided in which fuel-air ratio is less than stoichiometric, NOx is produced at one level, and combustor flow rate is high. In a second regime, fuel-air ratio is nearly stoichiometric, NOx production is less than that of the first regime, and combustor flow rate is low. In a third regime, used for example at lightoff, fuel-air ratio is greater than stoichiometric and the combustor flow rate is less than in either of the other regimes.

Abstract: An invention is disclosed for the attachment of a yoke to a laminated material composed of a medial matrix laminated between first and second skins. Two elongated parallel brackets are attached to the laminated material, the brackets each having a first segment fastened to the first skin, a second segment fastened to a first region of the second skin, and a third segment fastened to a second region of the second skin. The first and second regions are separated by a cavity in the second skin. The yoke is positioned in the cavity and fastened to the two brackets to provide a thrust point approximately coplanar with the second skin. The invention can be used to attach an actuator rod at the thrust point when the laminated material is that used in a cowling associated with a thrust reverser in a gas turbine aircraft engine.

Abstract: An invention is disclosed in which a signal indicating a rate of fuel flow desired for a gas turbine engine is bounded between limits imposed by maximal- and minimal-fuel rates allowed under the current operating conditions of the engine and between limits imposed by maximal- and minimal-accelerations allowed under the same operating conditions. The fuel rate limits are constantly modified by feedback information about the actual acceleration experienced by the engine. This feedback information about acceleration is obtained without directly measuring acceleration itself.

Abstract: An improved method for determining that coating has been removed from an article surface is provided for use in a method of removing a selected coating from an article surface having a composition different from the coating by impacting the coating with abrasive particles. The improved method includes selecting from the light spectrum a color which provides a color contrast between light emitted from the coating and light reflected from the article surface during coating removal in an impact intensity range using the abrasive particles. Provided is the selected color light environment in which the coated article surface is placed and then impacted with abrasive particles in the impact intensity range to create the color contrast and to remove coating from the article surface, the impact would be conducted until the color contrast disappears.

Abstract: In one form of the present invention, an apparatus for tightening a bolt stores information relating to an allowable relationship between change in bolt length and torque. A wrench applies a time changing torque to the bolt, the change in bolt length is measured by timing a traveling acoustic pulse in the bolt, and comparison means ascertains whether the torque-length behavior of the bolt exhibits the allowable relationship.

Abstract: A method and apparatus for masking from treatment selected surfaces of a turbine blade. The blade is positioned in an apparatus which includes a holder enclosing the airfoil section of the blade and a distinct spaced apart mask member elastically secured to the holder and having a deformable surface covering a surface of the blade spaced from the airfoil.

Abstract: In one form of the invention, means are provided for sensing changes in electrical power demanded from an electrical generator driven by a gas turbine engine. In response, other means change the rate of fuel and air delivery to the engine in proportion to the demand changes and keep the combustor fuel-air ratio substantially constant.

Abstract: An inlet particle separator for a gas turbine engine is provided with unique vanes distributed around an entrance to a particle collection chamber. The vanes are uniquely constructed to direct extraneous particles that enter the engine into the collection chamber and prevent the particles from rebounding back into the engine's air flow stream. The vanes are provided with several features to accomplish this function, including upstream faces that are sharply angled towards air flow stream direction to cause particles to bounce towards the collection chamber. In addition, throat regions between the vanes cause a localized air flow acceleration and a focusing of the particles that aid in directing the particles in a proper direction.