Abstract: A superconductive magnet subassembly has a single unbroken length of superconductive conductor which has a mid portion wound so as to define at least one superconductive magnetic coil and which has two end portions superconductively joined together by a superconductive joint. A superconductive switch is at least partially defined by the two end portions and by a heater for controllably heating the two end portions.

Abstract: A subassembly for an ice maker includes a plastic ice cube tray having a housing located within and attached to the refrigerator freezer. The housing has spaced-apart ice cube cavities. An electrically heatable metallic film coating is attached to and generally covers the cavity surfaces. When the cavity surfaces have been heated to detach the formed ice cubes therefrom, in one embodiment, a mechanism is provided to rotate the tray upside down to release the ice cubes. In another embodiment, a fixedly-"upside-down" and semicircular-cylindrical-shaped ice cube tray is placed in a trough, which also has an electrically heatable metallic coating, and a mechanism is provided to rotate the trough to uncover the openings of the ice cube cavities in the tray to release the formed ice cubes when the cavity and trough surfaces have been electrically heated to detach the ice cubes therefrom.

Abstract: A superconducting magnet including a superconducting coil assembly having a magnet cartridge, a cryocooler coldhead having a cold stage in thermal contact with the magnet cartridge, and a thermal buffer assembly. The thermal buffer assembly includes an inlet tube and an outlet tube each having an end connected to a helium pressure container which is placed in thermal contact with the magnet cartridge. A first gas pressure regulator on the inlet tube supplies helium gas and a second gas pressure regulator on the outlet tube vents helium gas so as to maintain a generally constant pressure for the helium gas within the helium pressure container. The high specific heat per unit volume of the pressurized gaseous helium acts as a thermal buffer to extend the time the magnet can operate superconductively without the cryocooler before quenching, such as during an electric power outage.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies each including a toroidal-shaped coil housing containing a superconductive main coil and a superconductive bucking coil. The bucking coil is spaced radially inward and radially apart from the main coil. The bucking coil carries an electric current equal in amperage, and opposite in direction, to the main coil. The bucking coils overcome the gross magnetic field distortions in the imaging volume of the main coils (created by the open space between the magnet's superconductive coil assemblies) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A method for matching the second output of a second sensor to the first output of a first sensor wherein a source transducer is driven by a reference analog or digital electrical signal to produce the physical quantity (e.g., acoustic pressure) the sensors (e.g., pressure sensors, such as microphones) can sense. A reference adaptive filter determines filtering coefficients to match the reference electrical signal to the first output of the first sensor and therefore models the source transducer and the first sensor (which typically is an independently-calibrated sensor). Thereafter, a second adaptive filter compensates the second output of the second sensor to match the output from a fixed filter having filtering coefficients identical to those determined by the reference adaptive filter, such output compensation of the second sensor not requiring the presence of the first sensor.

Abstract: A superconducting magnet lead assembly for a cryocooler-cooled superconducting magnet having a design current of between generally 50 and 250 amperes. A DBCO (Dysprosium Barium Copper Oxide), YBCO (Yttrium Barium Copper Oxide), or BSCCO (Bismuth Strontium Calcium Copper Oxide) superconducting lead has its ends flexibly, dielectrically, and thermally connected, one end to the generally 30 to 50 Kelvin first stage and the other end to the generally 8 to 30 Kelvin second stage of the cryocooler coldhead. The superconducting lead has a generally constant cross-sectional area along its length. The design current, the lead's length, and the lead's cross-sectional area are chosen such that the design current times the lead's length divided by the lead's cross-sectional area is between generally 720 and 880 amperes per centimeter for a DBCO or YBCO lead and is between generally 180 and 220 amperes per centimeter for a BSCCO lead. The superconducting lead will not itself precipitate a magnet quench (i.e.

Abstract: A magnetic resonance imaging (MRI) magnet having an annularly cylindrical-shaped vacuum enclosure with a longitudinal axis, first and second longitudinal ends, a first larger diameter bore extending from the first towards the second longitudinal end, and a second smaller diameter bore extending from the second longitudinal end to the first bore. First and second superconductive coils are placed in the vacuum enclosure with the first coil generally circumferentially surrounding the first bore and the second coil circumferentially surrounding the second bore, wherein the radial distance of the radially innermost portion of the second coil from the axis is smaller than the radius of the first bore. The second longitudinal end of the vacuum enclosure fits on a patient's shoulders with the patient's head passing through the second bore and extending into the first bore for MRI brain imaging.

Abstract: A fan assembly has a fan motor and first and second generally identical and spaced apart fans each rotationally attached to the fan motor to turn at the same rotational speed. Each fan has an equal number of generally identical fan blades and produces noise including a tone having a frequency equal to its rotational speed times its number of fan blades. The fan blades of one fan are angularly offset at a relative phase angle with respect to the fan blades of the second fan such that the tones of each fan generally cancel each other out. An equation is provided for a ducted fan assembly relating the relative phase angle to the rotational speed of the fans, the number of fan blades of each fan, the geometry of the duct, and the speed of sound in air within the duct.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies connected by spaced-apart structural posts each having a first end portion attached to the coil form of the first coil assembly and a second end portion attached to the coil form of the second coil assembly. Each toroidal shaped coil form has radially spaced-apart inner and outer generally cylindrical shells and has longitudinally spaced-apart inner and outer annular plates each attached to the inner and outer cylindrical shells. A superconductive coil surrounds, and is attached to, the outer surface of the outer cylindrical shell.

Abstract: A magnetic resonance imaging magnet includes a cryocooler penetration assembly and a superconducting coil assembly. The cryocooler penetration assembly has a thermal station within a thermal box within a vacuum vessel. The superconducting coil assembly has a magnet cartridge within a thermal shield within a vacuum enclosure. A flexible bellows hermetically connects the vacuum vessel and the vacuum enclosure. A first rigid thermal busbar is rigidly attached to the thermal shield, and a first flexible thermal busbar thermally connects the thermal box and the first rigid thermal busbar. A second rigid thermal busbar is rigidly attached to the magnet cartridge, and a second flexible thermal busbar thermally connects the second rigid thermal busbar and the thermal station.

Abstract: A flight vehicle scramjet combustor. The combustor, in its "2-D" and annular embodiments, has two spaced-apart, generally opposing, and longitudinally extending walls. One wall includes a generally aft-facing step having a first section and an interconnected second section, a forward wall portion attached to the first section, and an aft wall portion attached to the second section. The second section includes a fuel injector discharge orifice having a fuel discharge axis which is aligned generally perpendicular to the second section and which projects both generally towards the other wall and longitudinally aft. The combustor has a cylindrical embodiment which includes a cylindrical wall having a step and fuel injector discharge orifice similar those of the "2-D" and annular combustor embodiments.

Abstract: A gas turbine engine cooling system. A first turbocompressor and a heat exchanger are fluidly interconnected and are each in fluid communication to receive air of differing pressures and temperatures. Typically, such air is received from various regions of the engine low pressure compressor and the engine high pressure compressor. The system delivers air through a duct to a portion of the engine for cooling, such as the engine high pressure turbine region, at lower temperatures and higher pressures than if cooling air were directly ducted from the engine compressor to the engine turbine.

Abstract: A method of operating an aircraft bypass turbofan engine having variable fan outlet guide vanes. In a first embodiment, an engine out condition is sensed, fan rotor speed is repeatedly measured, and vane pitch is adjusted to a predetermined value as a function of the fan rotor speed to generally maximize airflow through the vanes during the engine out condition. In a second embodiment, vane pitch is adjusted to a preselected value as a function of fan rotor speed to generally minimize engine noise during a noise reduction mode of engine operation.

Abstract: Apparatus for controlling the clearance between the tips of a row of rotor blades and an array of surrounding shroud segments in a gas turbine engine. A torque tube is rotatably mounted on the engine casing and has a cam positioned inside the casing. First and second members are positioned inside the casing so as to be only axially moveable and so as to have their cam-engaging surfaces axially surround the cam, and they are biased such that the cam-engaging surfaces engage the cam. A shroud hanger, to which a shroud segment may be attached, includes axially spaced apart hooked flanges positioned to be engaged by hooked flanges of the first and second members. The flanges have axially inclined slide surfaces for such engagement, and the shroud hanger is biased radially inward to engage such slide surfaces. Clearance is controlled by rotation of the torque tube which axially moves the first and second members which radially moves the shroud segment.

Abstract: A front fan gas turbine engine subassembly which acts as a particle separator. The subassembly includes an aft-most row of full-size fan blades, a flow splitter, and a row of stator vanes. The flow splitter separates the fan exit air into a core engine airflow and a surrounding bypass airflow. The stator vanes each have a first portion disposed radially inward of, and longitudinally forward of, the leading edge of the flow splitter. The subassembly, in essence, has moved the leading edge of a conventional flow splitter aft without also moving the forward-most row of stator vanes aft. This means that particles which would strike a conventionally-positioned flow splitter and be reflected radially into the core engine airflow will instead miss the aft-moved leading edge of the flow splitter to radially outwardly bypass the core engine airflow.

Abstract: A rotor blade such as a turbine rotor blade for a jet engine. The airfoil blade portion of the rotor blade has a plurality of longitudinally extending coolant passageways preferably interconnected to define a serpentine coolant circuit. Passageways channeling coolant from the blade root to the blade tip are positioned in a first row proximate the pressure side of the airfoil blade while passageways channeling coolant from the blade tip to the blade root are positioned in a second row adjacent the first row and proximate the suction side of the airfoil blade to take advantage of the Coriolis force acting on the coolant in the passageways of the rotating blade to improve overall heat transfer effectiveness.

Abstract: A jet engine fan nacelle which maintains attached flow during engine windmilling. The nacelle includes a cylindrical airfoil body having an inner surface. A plurality of vortex generators are positioned on the inner surface between the nacelle body's leading edge and its throat within ninety degrees of rotation from the crown line hilite about the nacelle's longitudinal axis. The vortex generators energize the airflow to maintain an attached flow around the leading edge and along the outer surface of the nacelle's body without separating from the outer surface which would produce an undesirable increase in drag.

Abstract: A rotor blade such as a turbine rotor blade for a jet engine. The airfoil blade portion of the rotor blade has a plurality of longitudinally extending coolant passageways preferably interconnected to define a serpentine coolant circuit. Each passageway has a wedge shape including a base and an opposing tapered tip. For passageways channeling coolant from the blade root to the blade tip, the bases are positioned proximate the pressure side of the airfoil blade and the tapered tip is positioned proximate the suction side of the airfoil blade to take advantage of the Coriolis force acting on the coolant in the passageway of the rotating blade to improve overall heat transfer effectiveness.

Abstract: Apparatus for preloading an airfoil blade attached to a rotor disk in a gas turbine engine. The dovetail root of a composite fan blade is preloaded to prevent rubbing and wear against the dovetail slot of a metal rotor disk during fan windmilling, with the aircraft engine off, due to wind and breezes at the airport. A resilient material is inserted into the lower portion of the slot below the engaged blade root. The disk has a radius which intersects the slot. The material is acted upon by a device which adjustably compresses the inserted material perpendicular to the radius of the disk. This causes the compressed material to exert a radially outward force against the bottom of the engaged root of the blade.

Abstract: A heat exchange system for a supersonic flight vehicle. A first conduit connects the gas (e.g., helium) exit of a compressor of a gas-driven turbocompressor to the gas inlet of a turbine of the turbocompressor, and a second conduit connects the gas outlet to the turbine to the gas entrance of the compressor. The first conduit has a portion positioned near a hotter temperature region (e.g., the combustor wall) and the second conduit has a portion positioned near a colder temperature region (e.g., the fuel region) of the flight vehicle. The temperature difference self powers the turbocompressor which can transfer large amounts of heat and which is hermetically-sealed in a housing against gas leaks.