Abstract: A nonsquinting end-fed quadrifilar helical antenna is provided. Each conductor of the antenna is fed with a successively delayed phase representation of the input signal to optimize transmission characteristics. Each of the conductors is separated into a number Z of discrete conductor portions by Z-1 capacitive discontinuities. The addition of the capacitive discontinuities results in the formation of an antenna array. The end result of the antenna array is a quadrifilar helical antenna which is nonsquinting (radiates in a given direction independently of frequency).

Abstract: A blade is locked into groove in the periphery of a turbo-machine rotor by forming mating notches in opposing faces of the blade root and groove so as to form a blind hole. At assembly, a slotted radial pin is installed into the blind hole so as to prevent axial motion of the blade root. The pin is rotated so as to align its slot with a slot formed along the length of the rotor groove. A retaining strip is slid into the rotor groove slot so that it extends through the slot in the radial pin, with a pre-bent end of the strip resting against one face of the rotor. A tab formed on the other end of the strip is bent against another face of the rotor so as to lock the retaining strip in place. At dis-assembly, one of the retaining strip tabs is unbent and the retaining strip slid out. The pin is then extracted, thereby allowing the blade to be removed.

Abstract: Method and joint for sealing a bare hole in a nuclear heat exchanger tubesheet. The tubesheet has a plurality of holes formed therethrough, wherein at least one of the holes has been left vacant by a heat transfer tube removed from the hole. Such a hole is defined as a bare hole. One embodiment of the method of the invention comprises disposing a sleeve in the bare hole to protect the tubesheet material from the corrosive attack of the heat exchanger primary coolant and sealingly disposing a sleeve plug in the sleeve in order to seal the sleeve. A leak-tight joint is defined as the sleeve plug is sealingly disposed in the sleeve.

Abstract: Apparatus for attenuating vibration of a tube includes a cable disposed in the tube and spaced-apart attenuating assemblies mounted on the cable for frictionally engaging the wall of the tube in order to damp vibration of the tube. The assemblies also add rigidity to the tube in order to stabilize the tube against vibration. Each attenuating assembly comprises two spaced-apart end fittings mounted on the cable. A heat vaporizable insert is interposed between the end fittings for maintaining the end fittings in their spaced-apart relationship until the insert vaporizes. A preloaded coiled spring, which interconnects the end fittings and surrounds the insert, biases the end fittings towards each other after the insert vaporizes. A tubular, flexible and braided sheath, which is interposed between the end fittings, surrounds the spring and has respective ends thereof attached to the end fittings. When the insert vaporizes, the spring biases the end fittings closer together, thereby axially shortening the sheath.

Abstract: An in-line, multi-stage pump powered by integral canned electric motors. At least two pump units are connected in series in a pipeline. Each of said pump units includes a hollow housing having a hermetically sealed stator mounted therein. The stator is electrically connected to a source of electrical energy. An impeller assembly that includes a tubular suction shroud and impeller is rotatably mounted inside the housing. The impeller assembly includes a hermetically sealed rotor which is mounted around the suction shroud and positioned inside the stator in operative association therewith. Energizing the stator rotates the rotor, which in turn rotates the impeller to pump fluid from the intake end of the housing to the outlet end of the housing. The subsequent pump units add pressure and/or maintains the pressure of the pumped fluid.

Abstract: A gas turbine combustor having a pre-mixing zone and a combustion zone separated by a barrier plate. A plurality of concentrically arranged annular passages, into which lean mixtures of fuel and air are introduced, are disposed in the pre-mixing zone. Each of the annular passages has a discharge end in which a plurality of swirlers are circumferentially arranged that allow fuel/air mixtures flowing through the annular passages to enter the combustion zone, the swirlers acting as flame holders. A toroidal fuel manifold upstream of each of the annular passages allows the fuel/air ratio in each annular passage to be individually controlled. The firing temperature of the combustor is increased by sequentially supplying fuel to each annular passage in turn, with the innermost passages being supplied with fuel first. A pilot fuel assembly is centrally disposed with respect to the annular passages and has swirler vanes and an ignitor.

Abstract: A small low power portable transmitter for remote covert surveillance is disclosed. The transmitter includes a scrambler, forward error correction encoder, differential encoder, spread spectrum system and a modulator. The transmitter may be configured to transmit a single input signal or multiple input signals. The transmitter is powered by a portable single voltage power supply. All digital components of the transmitter may be implemented in a field programmable gate array and the transmitter may be easily modified to accommodate different applications.

Abstract: A turbomachine assembly includes a number of circumferentially spaced rotor blades, a number V of circumferentially spaced guide vanes axially adjacent to the rotor blades, an annular chamber surrounding the rotor blades, and an intake and exhaust for receiving and discharging air that passes through the annular chamber. When the turbomachine is in operation, spinning mode tones are generated by the interaction of the rotor and guide vanes. These tones are minimized by selecting a number of vanes relative to the number of blades so that selected tones propagate axial to the intake and exhaust of the turbomachine. A sound absorptive material is then positioned so that the tones impinge upon it. Moreover, a tuned duct is positioned in the path of the remaining tones. The turning vanes, placed within the tuned duct, cancel the remaining tones travelling through the duct.

Abstract: Rotary combustor and spring assembly therefor. The combustor includes a tire surrounding a kiln and a spring assembly interposed between the tire and kiln for interconnecting the tire and kiln. The spring assembly includes a clevis member attached to the tire and a spring member having an end portion thereof pivotally connected to the clevis member and an intermediate portion thereof attached to the kiln. The other end portion of the spring member is pivotally connected to an adjacent clevis member. The spring member allows for relative motion of the tire and the kiln as the first and second end portions of the spring member pivot about their respective clevis members.

Abstract: The inter-disk cavity between turbine rotor disks is used to pressurize cooling air. A plurality of ridges extend radially outwardly over the face of the rotor disks. When the rotor disks are rotated, the ridges cause the inter-disk cavity to compress air coolant flowing through the inter-disk cavity en route to the rotor blades. The ridges eliminate the need for an external compressor to pressurize the air coolant.

Abstract: In an electrodynamic apparatus, a method of securing a coil basket of the type that includes a plurality of top coils and a plurality of bottom coils to a bracing assembly that includes a plurality of support braces includes steps of banding the top coil, the bottom coil and the support brace to each other; positioning a number of inflatable bladders, respectively, between the top coils and the bottom coils in the location of the bandings; and simultaneously inflating the bladders to a predetermined pressure that is sufficient to tension the bandings to a predetermined force, whereby forces that are transmitted to the coil basket from such inflation are imparted evenly throughout the coil basket and at the same time.

Abstract: A low pressure steam turbine and generator low alloy steel disc rotors with extended useful life properties. A ring member of the disc rotor has disposed on it multiple weld layers of ferrous material, forming a weld region. The ring member is made of a low alloy ferrous metal alloy having less than about six weight percent alloying ingredients including chromium. The chromium content of the weld region increases overall from a portion of the weld region adjacent to the ring member to a portion of the weld region farthest from the ring member. This general increase is accomplished using weld metal of a single chromium concentration of between 9% and 17% chromium and varying the welding parameters.

Abstract: Apparatus and method for loosening a stuck reactor pressure vessel stud. A nuclear reactor pressure vessel has a threaded blind bore therein receiving an upright threaded stud having a centrally disposed passage longitudinally therethrough. A pulsar pump is in communication with the passage for supplying a pulsating liquid into the passage and thence into the bore. As the fluid exits the passage, it will push against the bottom of the bore and exert an upwardly directed hydraulic force against the end of the stud for upwardly lifting the stud. A controller is connected to the pulsar pump for controllably operating the pulsar pump. As the hydraulic force of the pulsating fluid lifts the stud, the fluid will migrate between the threads of the stud and the bore for peening or removing any debris from therebetween and washing it upwardly between the stud and bore to a suction pump in communication with the bore. The suction pump suctions the debris-containing liquid from the bore.

Abstract: A journal bearing is disclosed with shoe segments. Each shoe segment has a supply groove for even distribution of oil across the shoe surface during shaft rotation. The supply grooves have bleed vents that relieve pressure build-up in the supply groove by bleeding oil out of the supply groove in a substantially circumferential direction. Directing oil in this way prevents the pressurized oil from impinging on any nearby seals and provides enhanced temperature profile characteristics.

Abstract: An apparatus and method are disclosed for controlling the power flow in an electric transmission system including at least two transmission lines, each transmission line having two ends and carrying alternating current at a selected transmission line voltage and fundamental frequency between the ends. At least two alternating voltages at the fundamental frequency of the alternating currents flowing in the transmission lines, with variable magnitude and controllable phase angle relative to the transmission line current, are generated and coupled in series with the transmission lines. The magnitude and phase of each generated voltage are controlled selectively and individually to adjust the effective reactive and real impedance of each transmission line, to control the real power transmitted between the two ends of the transmission line and, concurrently, to control the amount of real power individually transferred between the transmission lines.

Abstract: Segmented stayrod for restricting transverse displacement of a nuclear heat exchanger tube support plate. The stayrod includes a first rod segment interposed between the tubesheet and the first support plate, the first rod segment having an externally threaded riser extending through the hole formed in the first support plate. The stayrod also has a second rod segment interposed between the first support plate and the second support plate, the second rod segment having an internally threaded end portion for threadably engaging the threaded riser of the first rod segment. The second rod segment also has an externally threaded riser extending through the hole formed in the second support plate. An internally threaded fastener threadably engages the riser of the second rod segment for fastening the second rod segment to the second support plate. In this manner, the first support plate is captured between the first rod segment and the second rod segment.

Abstract: The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor.

Abstract: An aerodynamically optimized mid-span snubber for combustion turbine blades provides sufficient stiffness to ameliorate vibratory stress but does so with minimal degradation of aerodynamic performance. The snubber has an optimized aerodynamic cross-sectional shape that forms when two snubber portions attached to adjacent rotor blades come into contact upon rotation of the rotor at an operational velocity.

Abstract: A non-squinting helical antenna is divided into segments separated by a coupler. This coupler is preferably a four port coupler which serves as a summation and difference power divider. Such a four port coupler allows the formation of a closed loop for controlling the steering angle of the antenna. The summation and difference signals between segments are monitored, and the ratio of these signals is used to determine and correct error in steering. The steering angle of the antenna can thus be maintained over a range of frequencies within a decibel of error.