Abstract: Apparatus for cooling the nozzle guide vanes in the turbine section of a gas turbine engine is disclosed. A plurality of guide vanes is cantilevered from the turbine case and extends radially inward across the path of working medium gases flowing through the turbine. A ring which is deformable in response to pressure forces is disposed between the vanes and the turbine case forming an annular chamber from which air is metered to the vanes during operation of the engine for cooling. In one embodiment platform cavities and airfoil cavities are alternately disposed between the vanes and the ring to isolate airfoil cooling air from platform cooling air.

Abstract: In a turbofan engine for jet aircraft the inner stream includes no noise suppression apparatus and the jet exhaust noise generated at takeoff is reduced by mechanically suppressing the jet exhaust noise of the outer stream and operating the engine at a bypass ratio, fan pressure ratio and gas generator power setting which yield a jet exhaust noise level from the suppressed outer stream which is louder than the jet exhaust noise level from the unsuppressed inner stream.

Abstract: A coolable shroud having a sealing surface surrounding the tips of the turbine blades of a gas turbine engine is disclosed. The shroud comprises a plurality of arcuate segments which are supported by the turbine case in end to end relationship concentrically about the axis of the engine. Each segment is adapted to receive and distribute cooling air about the walls of the shroud which are exposed to the hot working medium gases flowing through the turbine during operation of the engine. Cooling air is flowable to the gap between adjacent shroud segments to maintain continuity of the sealing surface across the gap.

Abstract: A rotary machine, such as a gas turbine engine, capable of reliable operation with improved overall cycle efficiency is disclosed. Various construction details which aerodynamically isolate internal cavities of the machine from the flow path for the working medium gases are developed. A sealing system built around the use of free vortex phenomenon reduces the amount of air which must be flowed through the cavity to prevent ingestion of the working medium gases into the cavity.

Abstract: Apparatus for diffusing the working medium gases which flow from the compression section of a gas turbine engine is disclosed. A controlled diffuser comprising an inner and an outer flow path shroud initially increases the static pressure and decreases the velocity of the medium gases flowing therebetween. The diffusion process is completed downstream of the flow path shrouds in a dump region of rapidly increasing flow area. The inner and outer shrouds of the controlled diffuser are concentrically supported at both the upstream and downstream ends. The inner and outer shrouds support the compressor exit vanes within the path of working medium gases flowing from the compressor and damp vane vibration during operation of the engine.

Abstract: A preconsolidated tape of continuous, high strength filaments in a metal matrix is coated with a layer of adhesive polymer and cut into shaped plies. The coated plies are stacked in a mold and resin bonded together by the application of heat and pressure. Many of the desirable physical properties of a diffusion bonded metal matrix article are also found in the resin bonded metal matrix article of the subject invention. Also, the use of preconsolidated adhesive coated plies eliminates the need for high diffusion bonding pressures and temperatures, thereby cutting the time involved for the bonding and molding operation by a factor of 8 in some instances.

Abstract: Apparatus forming a portion of the outer wall of the flow path for working medium gases in the turbine section of a gas turbine engine is disclosed. The vanes of each turbine stage are grouped into a plurality of vane clusters which are circumferentially disposed in adjacent relationship about the flow path. A shroud which surrounds the tips of the rotor blades immediately upstream of the vane clusters is segmented in integral ratio to the number of vane clusters. The gap between each pair of adjacent vane clusters is circumferentially positioned in axial alignment with one of the gaps between adjacent shroud segments.

Abstract: A disk having a closed channel construction and which is especially suited for supporting the rotating blades of a gas turbine engine is disclosed. In one embodiment, the disk supports the fan blades of a turbofan engine which extend radially therefrom. The disk structurally includes an upstream web, a downstream web and a plurality of arcuate plugs disposed in end to end relationship between the webs to form a toroidal type structure having a substantially rectangular cross section. The disk is contoured to provide a level of torsional and bending stiffness which limits the most critical stage vibratory frequencies to values above the engine operating range while limiting the maximum value of the disk hoop stress during operation to a level below the durability limits of the disk material utilized. A method for making the disk is further disclosed.

Abstract: Apparatus for varying the nozzle area in the turbine section of a gas turbine engine is disclosed. Nozzle guide vanes extend across the flow path for the working medium gases and are rotatable to alter the area of the nozzle. In one embodiment the rotatable vanes are cantilevered from the outer engine case and are opposed at their radially inner ends by a shroud which is affixed to the inner engine case. The outer engine case has a double wall type construction including a plurality of bearing cartridges disposed between the walls.

Abstract: Methods for forming a composite ring having unidirectional filaments embedded in a polymer matrix is disclosed. The filaments are spirally wound within the ring to form a plurality of essentially circular hoops which are in coaxial alignment with the expected lines of principle force. In one embodiment the formed ring is structurally integrated into the rotor of a gas turbine engine to reinforce the rotor and to restrain the rotor blades which extend outwardly of the ring.

Abstract: A turbine wheel assembly having an improved disk and sideplate construction is disclosed. A multiplicity of turbine blades is conventionally mounted on a turbine disk which includes a plurality of sideplate retaining lugs along the periphery of the disk. A plurality of segmented sideplates is affixed to the side of the disk and each blade has a root section which engages a correspondingly shaped slot in the disk. The lugs include an arcuate surface to engage a corresponding bearing surface on one of the sideplates and to radially retain the sideplate during rotation of the wheel assembly. Additionally, the rotation of the wheel assembly urges the sideplate axially against the side of the disk to seal the interface between the blade root sections and the corresponding disk slots.

Abstract: Apparatus for cooling the case and the nozzle guide vanes in the turbine section of a gas turbine engine is disclosed. A plurality of guide vanes is cantilevered from the case and extends radially inward across the path of working medium gases flowing through the turbine. A ring, which is deformable to provide radial sealing in operative response to pressure forces exerted by medium gases on the airfoil section of each guide vane, is disposed between the vanes and the case forming an annular chamber which is adapted to receive cooling air and from which the cooling air is flowable to the vanes during operation of the engine.

Abstract: A method and apparatus for providing high pressure cooling air to the turbine vanes of a gas turbine engine is disclosed. A centrifugal compressor stage is interposed in the flow path of cooling air to the turbine vanes. The centrifugal compressor stage raises the pressure of the cooling air to a value substantially greater than the pressure of the combustion gases entering the turbine. The availability of high pressure cooling air allows the incorporation of improved cooling systems in the turbine vanes. Increasingly effective cooling systems are necessary to the continued development of low pressure drop combustion chambers which discharge high temperature gases to the inlet of the turbine.

Abstract: A gas turbine disk design having a sideplate construction which prevents the leakage of hot gas across the turbine disk is disclosed. The sideplates are segmented and facilitate cooling of the turbine blades. Slidably mounted studs hold the sideplates in surface contact with the disk and prevent the buildup of stress concentrations in either the plates or the attaching members.