Abstract: A cantilevered turbine vane of the variable area variety is provided with unique retaining means to prevent relative movement between the vane and a fixed turbine housing through which the vane trunnion passes. Vernier adjusting means are provided to maintain a predetermined radial clearance between the vane and the fixed turbine housing, thereby eliminating binding between the two structures.

Abstract: A device is provided for increasing the power output of a gas turbine engine at the low ambient inlet temperatures which would otherwise produce a decrease in power. The device includes a conduit for bypassing a portion of the compressor discharge air around the combustor whereupon it is reintroduced back into the engine downstream of the compressor-driving turbine and upstream of the power turbine, if any. A valve is provided to increase the bypass flow rate through the conduit at low ambient temperatures, the increasing bypass flow permitting the engine to operate at a higher fuel flow and cycle temperatures for the same compressor mass flow. The increased temperature with the same mass flow rate results in an increase in power.

Abstract: In a gaseous fuel delivery system for delivering gaseous fuel to the combustor of a gas turbine engine wherein the delivery system includes a fuel injector having a nozzle orifice, a gaseous fuel supply passage providing fluid communication between the nozzle orifice and a source of gaseous fuel under pressure, an improvement is presented comprising means for preventing pressure perturbations occurring within said combustor from compressing gaseous fuel in at least a portion of the fuel delivery system.

Abstract: A protection system for use with a bleed manifold of a gas turbine engine is provided and is comprised of barrier means disposed within the manifold for preventing at least a portion of incendiary particles entrained in a fluid flowing instream through the manifold from impinging upon a wall associated with said manifold. Shielding means are also provided for shielding engine casing bleed ports from impingement by the particles.

Abstract: A device is provided for containing blades of rotating turbomachinery comprising a high-strength ring supported in radial spacial relationship over the blade tips by means of a stationary support structure. The ring is supported in such a manner that it is capable of spinning with respect to the support structure when acted upon by a predetermined blade force.

Abstract: A high bypass ratio gas turbofan engine provided with a hybrid mixer for mixing that portion of the bypass stream equivalent to a bypass ratio of substantially two with the core engine hot gas stream. The mixture is passed through a common exhaust nozzle.

Abstract: A turbomachinery rotor blade includes an internal coolant cavity between a pair of radially extending side walls which combine to form an airfoil having an open end between the radial extremities of the side walls. A tip cap recessed within the open end partially seals the internal coolant cavity from the blade environment. The radial extremities of the side walls extending beyond the tip cap into proximity with a circumscribing shroud form a labyrinth seal for inhibiting leakage of the operating gas across the blade tip. A portion of the cooling air is routed from the internal coolant cavity, around the tip cap and through a multiplicity of generally radial channels formed within the radial extremities of the side walls to provide cooling thereof, and is thereafter discharged out of the open end of each channel at the tip of the side walls.

Abstract: A gas turbine engine having a compressor and an air-cooled turbine is provided with a cooling system for decreasing the temperature of the turbine cooling air. A compact heat exchanger, rotatable with the compressor, receives a portion of the pressurized air which is bled from the compressor. Relatively cool engine lubrication oil is pumped through the heat exchanger into heat exchange relationship with the pressurized air, thereby cooling the air and heating the lubrication oil. The cooled air is then routed to and circulated through the turbine blades to provide improved internal cooling thereof. The heated lubrication oil is collected from the heat exchanger and routed to a second heat exchanger wherein it is placed in heat exchange relationship with engine fuel to recover the heat extracted from the compressor bleed air and to return the heat to the engine operating cycle. The cooling system is designed to contain the lubricant in the unlikely event of a leak developing in the heat exchanger.

Abstract: The blades of a gas turbine are primarily cooled by the circulation of a coolant through the hollow interiors thereof by the thermosiphon principle. Each hollow blade interior is also placed in fluid communication with a secondary coolant source, but secondary coolant flow is precluded by a plug filling the inlet fluid passage. Similar plugs fill apertures in the form of casting holes through each blade airfoil portion, the holes serving to discharge the secondary coolant from the blade interior. The plugs are fabricated of a material having a lower melting point temperature than that of the remainder of the blade airfoil portion such that, in the event of failure in the primary cooling system, the plugs will melt, thereby permitting the secondary coolant to rush through the blade and provide internal cooling thereof.

Abstract: A nacelle for use with a gas turbine engine is provided with an integral webbed structure resembling a spoked wheel for rigidly interconnecting the nacelle and engine. The nacelle is entirely supported in its spacial relationship with the engine by means of the webbed structure. The inner surface of the nacelle defines the outer limits of the engine motive fluid flow annulus while the outer surface of the nacelle defines a streamlined envelope for the engine.

Abstract: An inlet for a gas turbine engine is provided with a fixed geometry upstream lip defining the primary inlet flow passage, and a variable position downstream lip partially defining an efficient auxiliary fluid flow passage through the inlet. The upstream lip is sized to pass all of the engine flow requirements at a near-sonic average Mach number during engine approach operating conditions. Apparatus is provided to position the variable lip for modulating flow through the auxiliary passage during higher engine power settings.

Abstract: A turbomachinery stage comprising two axially spaced blade rows, one of which is rotatable, wherein the blades of the upstream row are contoured to present a leaned wake to the downstream row. In the preferred embodiment, the blades of the upstream row extend radially from a central hub and, at a radius above the hub, are physically curved circumferentially from a radial line through the hub. The physical lean locally complements the inherent aerodynamic lean at each radius such that the integrated acoustic power of the stage is essentially at a minimum, thus maximizing the acoustic attenuation. Preferably, the constraint is imposed that the blade physical curvature is essentially smooth, continuous and without an inflection point.

Abstract: An acoustic suppression panel is provided with a perforated plate covering a layer of a bulk absorber. A flexible, fluid-impervious membrane is placed between the plate and the bulk absorber, and supported in a manner so as to permit the membrane to become essentially acoustically transparent. An acoustically hard backing plate is disposed adjacent the bulk absorber, the backing plate being provided with perforations to allow pressure equalization for flight applications. A facing sheet of sintered metal covers the perforated plate to provide an aerodynamically continuous flow surface for the plate which is highly resistant to foreign object impact.

Abstract: A turbomachine such as a compressor having one or more rows of blades designed to operate at a supersonic inlet relative Mach number is provided with a manifold surrounding the blade tips for extracting air from the passages between adjacent blades by an amount generally inversely related to the inlet relative Mach number, thereby restructuring the shock pattern. Extraction rate is modulated by a valve operatively connected to the turbomachine fuel control system.

Abstract: A method of fabricating a turbomachinery blade is provided whereby high stress levels associated with stripe mode resonance can be avoided. Once the nodal pattern for an objectionable stripe mode resonance condition of a metallic blade is determined by conventional means, a portion of the blade parent metal near the tip is replaced with a composite patch, the composite patch comprising elongated filaments embedded in a matrix material. The chordwise extent of the patch includes the nodal points at the objectionable stripe mode resonance condition and the filament orientation is chordwise to enhance chordwise stiffness.

Abstract: A rotating member such as a turbine disk is provided with an axially extending retaining means such as a ring having a plurality of D-shaped, open-ended slots formed about an edge thereof. A collar embracing a generally radially extending tube is received within each contoured slot and a pair of laterally extending lips formed upon each collar receive and engage the ring therebetween, thereby limiting radial movement of the collar. A circumferentially extending groove about the inner circumference of the ring intersects each groove and receives a split locking ring to limit axial movement of the collars and tubes.

Abstract: Two overlapping members subject to relative displacement and separated by a gap for spreading a pressurized fluid as a film over the overlapped member are provided with a metering device for providing an essentially constant fluid flow area irrespective of the size of the gap resulting from differences in relative displacement of the members. The metering devices comprise a flexible seal connected to one of the members, the seal being of such a length that it engages in sealing contact the other member under the influence of the pressurized fluid. Orifices of a predetermined size and number formed within the seal provide a generally constant flow area for metering the fluid prior to passage through the gap.

Abstract: Sound-suppressing structure comprising stacked acoustic panels wherein the inner high frequency panel is mounted for thermal expansion with respect to the outer low frequency panel. Slip joints eliminate the potential for thermal stresses, and a thermal expansion gap between the panels provides for additional relative thermal growth while reducing heat convection into the low frequency panel.

Abstract: A phased treatment noise suppression panel is provided for use in an exhaust duct. The panel consists of individual sections designed with specific modal attenuation characteristics and located axially within the duct in such a sequential order, with respect to the noise source, as to take maximum advantage of modal redistribution effects on overall noise suppression.

Abstract: A high temperature turbine shroud assembly for an aircraft gas turbine engine comprising a plurality of arcuate ceramic blocks arranged in a ring. The blocks are supported by a pair of annular support members which retain the blocks in the assembly. Spring-like fingers associated with the support members apply a preloaded force against a pair of slanted dovetail surfaces on the blocks to force the blocks against rigid stops formed upon the annular support members, thereby establishing their proper radial position within the assembly. The preload applied by the fingers accommodates the thermal expansion differences between the ceramic blocks and the metallic support members. In an alternative embodiment, the blocks are retained between cooperating rigid legs extending from the annular support members and wedged radially inwardly into position by a preloaded spring contacting the back side of the blocks.