Abstract: A retainer assembly for retaining a bolt in engagement with a first member during assembly or after disassembly of the first member from a second member comprises a retainer formed with a throughbore and an annular slot at one end of the throughbore, a bolt having a shank formed with a smooth section, a threaded section and a groove therebetween, and a triangular-shaped locking ring which is carried within the slot formed in the retainer. The threaded section of the shank of the bolt is first inserted through the locking ring and then into the throughbore of the retainer for mounting within a threaded bore formed in a second member. Upon disassembly of the bolt from the second member, the bolt is moved in the opposite direction along the throughbore of the retainer until the locking ring engages the groove in the shank of the bolt which prevents disengagement of the bolt from the retainer.

Abstract: A heat shield assembly for use in a turbine engine frame includes inner and outer flowpath liners for shielding the inner and outer turbine frame members from hot exhaust gasses flowing through the turbine engine. The flowpath liners are supported on the turbine frame members with a support structure which allows the flowpath liners to freely expand and contract under thermally induced forces. In this manner thermal stresses are minimized. The flowpath liner support structure also provides uniform support for the flowpath liners and allows for the even and unobstructed flow of cooling air through the flowpath liners.

Abstract: The present invention provides a high bypass turbofan engine configuration wherein a fan drive turbine is divided into first and second turbine sections mounted for independent rotation within the engine frame. The first, higher pressure, higher speed turbine section is coupled to the fan section drive shaft via a gear box which reduces the rotational speed of the power delivered by the higher pressure first turbine section to match the design rotational speed of the fan section. The second turbine section, having a larger diameter and lower rotational speed as compared to the first turbine section, is directly connected to the fan section and drives the fan section at the same rotational speed as that of the second turbine section. In this manner, the fan drive shaft horsepower is provided while reducing the weight and size of the necessary gearing between the fan drive turbine and the fan. The weight and size of the fan drive turbine and the booster compressor are also reduced.

Abstract: Heat flux distribution and heat transfer coefficient distribution over a surface of a component used in a high temperature environment are determined by supplying coolant of predetermined characteristics to the component and measuring a temperature distribution over a predetermined surface. The heat flux at each temperature measurement point on the surface of the component is determined from heat flux calibration data obtained before the component is placed in service and while it is being operated at in-service cooling conditions. The heat transfer coefficient at various locations on the surface of the component is determined from the heat flux indicated by the heat flux calibration data, the temperature of the surface, and the temperature of the environment in which the component is situated.

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 annular rings of high temperature material mounted by means of flexible 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. The individual liner rings may be easily removed for repair or replacement without disassembling the frame and associated components. Furthermore, the "decoupling" of thermal and structural stresses provides longer life and more dependable operation.

Abstract: An annular cast inner support member is concentrically mounted within an annual cast outer support member for mounting a plurality of radially extending outlet guide vanes within the flowpath of a gas turbine engine. The outlet guide vanes are resiliently connected to the inner and outer support members to control and limit the compressive loading of the outlet guide vanes caused by thermal stresses during engine operation. A resilient clamped interconnection which is particularly suitable for use with ceramic outlet guide vanes includes a bolted and clamped socket assembly which maintains both radial and circumferential compressive forces on the outlet guide vanes at all times, notwithstanding the differences in thermal growth rates between metal and ceramic materials.

Abstract: A dual manifold fuel supply system for the combustor of gas generator in a turbofan engine wherein alternating circumferentially aligned fuel injectors are alternately supplied with fuel by a first or second fuel manifold. Fuel flow to both manifolds are controlled by a fuel control, preferably a full authority digital electronic control, and the second manifold has an off valve interposed between it and the fuel control.

Abstract: A low turbulence, close-coupled mounting structure for a flame holder disposed in an afterburner section of a gas turbine engine is provided. The afterburner section has a plurality of angularly spaced, radially extending fuel injection nozzles, with a fairing surrounding each nozzle to form open ended heat shields about the nozzles. A flame holder having a first cross-sectional configuration is disposed in recessed portions formed in the fairings surrounding the nozzles. The cross-sectional configuration of the recessed portions is configured to substantially conform to a portion of the cross-section of the flame holder such that the flame holder is recessed into the fairings when mounted thereon, thus eliminating outward projections at the connection of the flame holder and fairings. The flame holders are secured in the recessed portions by pins extending through aligned apertures in the skirts of the flame holder.

Abstract: The thermal performance of cooling circuits for cooled components, such as turbine blades used in gas turbine engines, may be determined by applying a known amount of heat flux to a predetermined surface of the component, directing a cooling fluid flow having predetermined characteristics through the cooling circuit of the component, and measuring a temperature distribution on a preselected surface of the component.The thermal performance of heating circuits for heated components, such as those involved in clearance control in a gas turbine engine, or other components in which a controlled thermal contraction or expansion is desired, may be determined by applying a known amount of heat flux to a predetermined surface of the component, applying a cooling fluid flow having predetermined characteristics to the heating circuits, and measuring a temperature distribution on a preselected surface of the component.

Abstract: A shield is disposed in spaced relationship to the exterior surface of the combustor liner of a gas turbine engine and extends over a plurality of very small holes formed in the combustor liner so as to block flow of air to these holes. Further, the shield provides a space between the shield and the combustor liner for receiving reverse flow of air. A portion of the air flowing along the exterior surface of the combustor liner is diverted for reverse flow in the path provided between the shield and the combustor liner. A lesser plurality of substantially larger holes are provided in the combustor liner at the point of reversal of the air so that the dirt particles in the air, because of the centrifugal force acting thereon, tend to flow through these larger holes. A second group of larger holes are provided in the combustor liner approximately at the forward end of the space between the shield and the combustor liner.

Abstract: An improved turbine blade tip with diffusion cooling holes in the tip is disclosed. One particular embodiment of the invention provides an improved squealer blade tip with diffusion cooling holes in the tip. Yet another embodiment of the invention provides blade tip diffusion cooling holes comprising a first cylindrical portion coupled to a second conical portion.

Abstract: A boltless blade retainer for preventing forward axial movement of the rotor blades in a turbo machine relative to the rotor disk comprises an annular extension or hook formed on each dovetail post on the web of the rotor disk, an impeller or blade retainer formed with a flange which is carried against the web and dovetail posts and a retaining ring interposed between the hooks of the dovetail posts and the flange of the impeller. The retaining ring secures the impeller in a fixed axial position relative to the dovetail posts and rotor disk, and is positioned to engage the rotor blades carried in the axial slots between adjacent dovetail posts to prevent their movement in a forward axial direction.

Abstract: An improved system provides cooling air to the turbine blades of a gas turbine engine. The improved system includes the combination of an inducer to receive pressurized cooling air from the compressor and then to direct this cooling air in a substantially tangential direction to a radial flow impeller which includes an air seal. Cooling air is directed to the turbine blades which are mounted on the rim of the rotating first turbine disk. In a preferred embodiment of the invention, a second portion of the cooling air from the inducer is conveyed through a deswirler to introduce the cooling air into a circumferential channel surrounding the rotor shaft. The cooling air is then directed to a second inducer means which is mounted on the higher pressure turbine disk. The cooling air is then directed to a second annular impeller mounted on the lower pressure turbine disk to convey this portion of cooling air to the lower pressure turbine rotor blades.

Abstract: A mounting assembly for supporting stator vane platforms formed in an extended arc length, in a compressor casing, comprising a circumferential flange formed in the compressor casing having spaced clamp arms, a flange carrier on each stator vane platform having a surface which is formed with a plurality of radially outwardly extending wedge lock elements, and locking springs having inner and outer sides each formed with wedge lock elements extending radially outwardly therefrom. In order to mount the stator vane platform on the compressor casing, the locking springs are placed in an "unlocked" position on the flange of a stator vane platform wherein the wedge lock elements on the inner side of the locking spring extend between adjacent wedge lock elements on the flange. The vane platform flange and locking spring are then inserted as a unit between the clamp arms of the compressor casing.

Abstract: A method for replacing a damaged or defective section of a length of original piping or tubing located within a structrue such as the turbine of a jet engine wherein access to the tubing is limited, and replacing such damaged section with a new section of tubing comprises inserting a cutter mounted at one end of a flexible shaft into the interior of the original tubing and rotating the shaft to cut out and remove the damaged section of tubing leaving at least one stub section of original tubing. The stub sections of original tubing are then prepared for welding or brazing to a section of replacement tubing with a series of tools each mounted to an elongated shaft. These tools include a chamfering tool, a deburring tool, and a polishing tool.

Abstract: A lightweight counterrotatable propeller system driven by a rotatable shaft is disclosed. The system includes first and second counterrotatable propellers, each propeller including a plurality of blades mounted on first and second hubs, respectively. Each blade is attached to the hub by means of a ball screw which converts centrifugal force on each of the rotating propeller blades into a pitch changing force. Gearing means for operatively connecting the shaft with each propeller are located between the propellers with a carrying member for one of the propellers forming an outer wall which radially bounds the gearing means. Additionally, non-rotating actuating means for changing propeller pitch are operatively connected to the blades of each of said first and second propellers through first and second thrust bearings, respectively.

Abstract: A turbomachinary airfoil in one form comprises a pressure side and a suction side curved circumferentially outward in the direction that the suction side faces. The invention is effective for reducing both radial and circumferential boundary layer pressure gradients thereby reducing airfoil aerodynamic losses. In another form of the invention the airfoil is a vane of a turbine vane assembly having an inner and outer shroud wherein the vane in addition to being curved is leaned circumferentially outward in the direction that the suction side faces.

Abstract: A plurality of circumferentially displaced hollow members are positioned between an outer bypass duct and the center body of the core engine. Each of the hollow members is open at the radially outward end thereof for receiving relatively cool gas from the bypass duct. Each hollow member is formed with an opening in the side thereof extending substantially the full length of the hollow member near the trailing edge thereof for discharging bypass gas from the bypass duct in a direction facilitating thorough mixing of the bypass gas and core gases. A pivoted vane is provided in this opening of each of the hollow members and these vanes are controlled to vary the airflow through the aforementioned openings. Radially extending spraybars or fuel rods are provided within each hollow member adjacent opposite sides thereof so as to be cooled by the bypass air flowing through the hollow member.

Abstract: The present invention discloses means and method for modulating the bypass flow in a mixed flow, variable cycle gas turbine engine. The engine includes means to vary the bypass flow and includes an augmentor and liner with coolant supplied by a portion of the bypass flow. The bypass flow pressure is modulated by sensing the pressure of the liner coolant and the pressure in the augmentor and varying the flow pressure as a function of P.sub.1, P.sub.2, or both.

Abstract: Disclosed are a cooling air modulation apparatus for and method of operation for a gas turbine engine which are effective for increasing engine operating efficiency. According to one embodiment of the invention, the apparatus includes a first inducer means effective for channeling a first portion of cooling air to a rotor component during both first and second modes of operation of the engine. A second inducer means is also provided and is effective for channeling a second portion of the cooling air to the rotor component. Valve means are provided for selectively modulating the amount of cooling air flowing through the second inducer for preventing flow therethrough during the first mode of operation and for allowing unrestricted flow therethrough during the second mode of operation.