Abstract: A diagonal type MHD generator channel frame element, having a polygonal configuration which is preferably rectangular, is formed from two different pairs of pre-formed hollow bars, one of the pairs serving as the electrode members, while the other pair serves as the electrode-interconnecting diagonal members. The electrode members have cross-sectional profiles corresponding to that of a parallelogram while the diagonal members have rectangular cross-sectional profiles. Pre-formed coolant passages are defined within the members in an entirely enclosed manner, and the cross-sectional profiles of the passages correspond to those of the members within which the passages are defined.

Abstract: A fluid-cooled element for partially defining hot gas flow passage extending upstream and downstream of a minimum area throat. A serpentine conduit of fluid communication with a coolant source routes cooling fluid within the downstream portion of the element wall bounding the hot gas passage to an internal pocket upstream of the throat. The coolant is thereafter exhausted upstream of the throat as a film over the wall. The upstream wall portion is cooled by the known impingement and film-cooling technique resulting in an element wherein all of the coolant enters the hot gas passage in a low Mach number region upstream of the throat, thereby minimizing momentum losses due to mixing. In the preferred embodiment, the passage throat is defined by a plurality of turbine nozzle vanes, the fluid-cooled element comprising a nozzle band thereof.

Abstract: An insulated casing assembly for use in injecting steam into wells, comprising a plurality of interconnected casings, each casing having outer and inner tubular sections, an annular spacing between the two sections containing multilayered thermal insulation enveloped in a low conductivity gas, and tubular bellows connecting and allowing relative movement between the corresponding ends of the two inner sections. A leak-proof connection between adjacent casings includes a diffuser sleeve fitted tightly over the ends of adjacent inner tubular sections, a filler ring fitted on the diffuser sleeve and disposed between adjacent outer tubular sections, and a threaded coupling screwed onto threaded ends of outer tubular sections of adjacent casings.

Abstract: A heliostat enclosure that is particularly well suited for enclosing and protecting a heliostat either flat or parabolic, preferably comprising a light-weight, generally hemispherically shaped, enclosure bubble that is formed of readily assemblable and disassemblable segments, including some transparent segments, and supported by a foundation in the form of a soil filled, plastic ring bag that is mounted in the ground at the heliostat site. The enclosure bubble is inflatable by pressurized air and supportable in operation, such as during windy or inclement weather. A multi-legged, tubular, step frame is mounted within the enclosure bubble and is configured to support the enclosure bubble in nearly fully inflated condition when the bubble is not supported by pressurized air. The frame is electrical conducting and grounded, thereby also serving as a lightning protection means for the heliostat.

Abstract: Gas turbine engine thrust is controlled by automatically adjusting compressor rotational speed with novel functions of engine inlet temperature to hold thrust to rated values for varying engine inlet temperature conditions. Furthermore, compressor rotational speed is automatically adjusted as a function of inlet pressure to provide a thrust rating schedule which varies with altitude. Compressor corrected rotational speed is limited through a novel function of engine inlet temerature to protect against turbine overtemperature when the engine inlet temperature exceeds the flat thrust rating point.

Abstract: An air-to-air heat exchanger is provided for a gas turbofan engine to significantly reduce the quantity of cooling air that is presently needed to effectively cool the hot turbine parts. Typically, the turbine is internally cooled with air bled from the compressor which, though cooler than the turbine, has been heated due to the work done on it by the compressor. In accordance with the present invention, the heat exchanger is located internally of the bypass duct to place in heat exchange relationship a captured portion of the relatively cool bypass flow and this warmer compressor bleed air, thereby cooling the turbine coolant and significantly reducing the amount of such coolant required. This results in a decrease in engine specific fuel consumption.

Abstract: A gas turbine engine comprising a fan, a compressor and a turbine, wherein the torque requirements of the fan or compressor can be modulated, is provided with differential gearing to transmit all of the fan and compressor power requirements from the turbine. The differential gearing maintains an adjustable speed relationship between the fan and compressor with respect to the turbine depending upon the torque requirements thereof and the gear ratios within the differential gearing.

Abstract: A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting.

Abstract: A turbine assembly is provided by which a variable area turbine vane may be cantilever mounted from an outer structural frame and further supported by an inner structural frame. The vane includes an inner trunnion about which is installed an inner band sector to partially define a flow path through the turbine. The band sector is provided with a hole which receives the trunnion. Once the vane is cantilevered from the outer frame and the band sector installed, an inner annular frame is slid under the vane trunnion to align a hole in the frame with the trunnion. A generally cylindrical trunnion extension is inserted through the frame hole and over the end of the trunnion, and then attached to the trunnion through a bolted connection. The extension is journaled for rotation within the inner structural frame hole. Passageways are provided to route cooling air from the vane into the structural frame to provide cooling of the band sector.

Abstract: An integrally cast structural cooling air manifold for a gas turbine engine being of generally annular shape and having two concentric thin walls defining a plenum therebetween. Each of the walls is provided with embossments through which aligned radial holes are bored to furnish support for a stage of rotatable vane trunnions. A series of circumferentially spaced inlet ports on the outer wall distribute cooling air into the plenum, from which it is routed to the vane airfoil portions to perform cooling functions by means of passages which commumnicate with the plenum via openings in the vane trunnions. Thus, the manifold performs the dual functions of distributing coolant to the vanes and supporting the vane trunnions in the manner of a turbine frame.

Abstract: An improved blade retainer for locking radially projecting blades on a rotor includes an elastic spacer sized to be inserted into a radial space between the blade tang and the bottom of the rotor slot in a generally undeformed state without deformation of the tang or slot. The spacer is provided with a first arcuate surface which abuts the tang and a second arcuate surface which, in one embodiment, abuts the bottom of the rotor slot when the spacer is deformed, thereby exerting an outwardly directed load on the tang. The spacer is fixed against axial movement relative to the blades by means of a forward end lug which is in confronting and overlapping relationship with an end face on the blade tang when the spacer is deformed. Blocker means are insertable between the spacer and the bottom of the slot to retain the spacer in a deformed state and thereby bias the blade radially outwardly.

Abstract: A centrifugal boost pump, a primary centrifugal pump and a dynamic machine are driven through a common drive shaft. At low speeds, such as during pump start-up, the elements are in the aforementioned fluid serial relationship such that the dynamic machine, functioning as a pump, provides the primary fluid pressurization. Once a predetermined primary pump discharge pressure is attained, a clutch disengages the centrifugal boost pump and dynamic machine from the primary centrifugal pump, and the discharge of the dynamic machine is routed to a low pressure source. Thereafter, primary fluid pressurization is accomplished by the primary centrifugal pump which also pumps fluid through the dynamic machine, now functioning as a motor and driving the centrifugal boost pump.

Abstract: An improved floating seal is provided to minimize leakage around the ends of a variable area turbine stator nozzle for use in cooperation with a circumscribing shroud. The seal is contoured to float within a pocket formed in the end of the nozzle vane which extends to the vane trailing edge. The forward end of the seal is forced into engagement with the shroud by the pressure of cooling air from within the vane. A seal surface attached to the trailing edge of the seal and projecting laterally of the vane utilizes the differential pressure across the vane airfoil surfaces to hold the trailing edge of the seal into engagement with the shroud. The improved floating seal reduces vane end leakage experienced by prior art floating seals.

Abstract: A compact apparatus for simulating the in-flight aerodynamic performance of a multimission aircraft propulsion system of the gas turbine engine variety having an external envelope of a reduced size in relation to the engine to be simulated. The apparatus includes a turbine driven by externally generated, high pressure motive air which is drivingly connected to a compressor in the usual manner of a gas turbine engine. The flow of air pressurized by the compressor is mixed with a portion of the relatively higher pressure turbine motive air so as to generate a mixed flow having a generally uniform pressure profile entering the exhaust nozzle. The compressor, turbine, mixer and nozzle are sized to produce a pressure ratio across the apparatus and a nozzle flow function which are substantially identical to the engine to be simulated, though these components are of a reduced size in relation thereto.

Abstract: The turbine blades of a gas turbine engine are individually cooled through the internal circulation of a fluid coolant by the thermosiphon principle. Each turbine blade has associated therewith a closed-loop coolant passageway which is rotatable with the turbine rotor disk and which, in one embodiment, passes through a heat exchanger borne by, and rotatable with, a rotatable lubrication duct. The blade internal coolant is placed in heat exchange relationship with engine lubrication oil within the heat exchanger. The heated lubrication oil is then placed in heat exchange relationship with the engine fuel and the fuel thus heated is burned in the combustor, thereby returning at least a portion of the heat removed from the turbine blades to the engine power cycle. The cooling system is designed for simplified blade removal and replacement and the entire turbine can be removed from the engine as a sealed unit.

Abstract: An improved windage shield is provided for use with turbomachinery members partially defining an internal flow path wherein the members are connected by a fastener which protrudes beyond one of the members. The windage shield comprises a portion which is captured between the fastener and one of the members and a cylindrical section which extends downstream of the members to form a smooth cover for isolating the members from the internal fluid flow. The protruding fastener end is recessed into, and generally flush with, the captured portion of the windage shield.

Abstract: A gas turbine engine comprising a number of annular wall sectors which form a complete circular wall defining a hot gas passage is provided with a cooling system incorporating a plurality of hollow impingement vessels disposed in a circular array within an annular chamber behind the wall. Cooling fluid is routed to the self-contained impingement pressure vessels which are provided with perforations to disperse the cooling fluid into impingement upon the wall. Unlike prior systems, the impingement vessels are not physically attached to the band but, rather, are supported by a structural frame which partially defines the annular chamber and, in the preferred embodiment, also supports the wall sectors. Since the impingement vessel, and not the backside of the wall, is the pressure vessel for the pressurized cooling fluid, leakage between adjacent wall sectors is greatly reduced with no loss in cooling effectiveness when compared to conventional cooling systems. Thus, turbine cycle performance is improved.

Abstract: A polygonal hydraulic actuation ring is provided for modulating the area of a variable position nozzle. The actuation ring comprises a plurality of actuators arranged end to end in the form of a polygon circumscribing a plurality of pivotable flaps, each of which is acted upon directly by one of the actuators. The actuators are synchronized by the use of gears and helical screws to expand and contract in unison, thereby changing the diameter of the polygonal actuation ring and the exhaust flow path area defined by the flaps. Rod end and head end hydraulic fluid flows are provided to all actuators simultaneously through a system of internal flow passages, and only one rod end supply line and one head end supply line are required for the entire actuation ring. Cooling is provided by an air film flowing over each hydraulic cylinder and by hydraulic fluid recirculation.

Abstract: A thrust reverser is provided for use with an asymmetric aircraft gas turbine engine exhaust nozzle. The thrust reverser includes a movable aerodynamic flap downstream of the asymmetric nozzle casing which is rotatable about one pivot in order to effect in-flight thrust vectoring through deflection of the exhaust stream, and which is also independently rotatable about another pivot to effect thrust reversing. In the reverse thrust mode, the leading edge of the flap is immersed into the exhaust stream, thereby splitting the stream into two portions, one of which is deflected upward and forward by a turning vane incorporated into the leading edge of the flap, and the other portion of which is deflected downward and forward by a hinged lip connected to the flap trailing edge. The thrust reverser thus permits the exhaust stream to be ejected in the vertical plane to produce reverse thrust without an accompanying pitch moment even though the exhaust nozzle is not symmetrical in the vertical plane.

Abstract: A double bypass, variable cycle gas turbofan engine is provided with a variable area bypass injector which varies the area through which the inner bypass stream is injected into the outer bypass stream. The bypass injector comprises an upstream variable area, double bypass selector valve, the position of which determines whether the engine will operate in the single or double bypass mode, and a downstream static pressure valve which defines an optimum flow path for injecting the inner bypass stream into the outer bypass stream. The ability to vary the area through which the inner bypass stream is injected into the outer bypass stream permits the static pressure valve to operate as an ejector and permits control of the two bypass air streams through creation of a static pressure balance at the exit of the variable area bypass injector.