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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,765 records · Page 98
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Solar space and water heating system installed at Charlottesville, Virginia

The solar energy system located at David C. Wilson Neuropsychiatric Hospital, Charlottesville, Virginia, is described. The solar energy system consists of 88 single glazed, Sunworks 'Solector' copper base plate collector modules, hot water coils in the hot air ducts, a Domestic Hot Water (DHW) preheat tank, a 3,000 gallon concrete urethane insulated storage tank and other miscellaneous components. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

Source record↗
NASA NTRS1981

Design, fabrication, and bench testing of a solar chemical receiver

Solar thermal energy can be effectively collected, transported, stored, and utilized by means of a chemical storage and transport system employing the reversible SO2 oxidation reaction. A solar chemical receiver for SO3 thermal decomposition to SO2 and oxygen was analyzed. Bench tests of a ten foot section of a receiver module were conducted with dissociated sulfuric acid (SO3 and H2O) in an electrical furnace. Measured percent conversion of SO3 was 85% of the equilibrium value. Methods were developed to fabricate and assemble a complete receiver module. These methods included applying an aluminide coating to certain exposed surfaces, assembling concentric tubes with a wire spacer, applying a platinum catalyst to the tubing wall, and coiling the entire assembly into the desired configuration.

Summers, W. A.↗
NASA NTRS1981

Solar space heating installed at Kansas City, Kansas

The solar energy system was constructed with the 48,800 square feet warehouse to heat the warehouse area of about 39,000 square feet while an auxiliary energy system heats the office area of about 9,800 square feet. The building is divided into 20 equal units, and each has its own solar system. The modular design permits the flexibility of combining multiple units to form offices or warehouses of various size floor areas as required by a tenant. Each unit has 20 collectors which are mounted in a single row. The collectors are double glazed flat plate collectors with a gross area of 7,800 sq ft. Air is heated either through the collectors or by the electric resistance duct coils. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are presented.

Source record↗
NASA NTRS1981

The development of an 85-kW (thermal) steam Rankine solar receiver

The receiver is a once-through monotube boiler designed for steam/electric and process steam applications at pressures up to 17.24 MPa (2500 psia) and temperatures up to 704 C (1300 F). The unit is 76.2 cm (30.0 in.) in diameter and 95.8 cm (37.7 in.) in length; it weighs 220 kg (485 lb). Its heat transfer surface, which is 45.7 cm (18 in.) in diameter by 57 cm (22.4 in.) long, is an Inconel 625, cylindrical, tube-coil assembly composed of primary and reheat sections. A test unit was successfully operated at up to 6.9 MPa (1000 psia) and 704 C (1300 F) with solar input from a 11-m-dia parabolic dish concentrator.

Wright, C. C.↗
NASA NTRS1980

Leading-edge 'Vortex Flaps' for enhanced subsonic aerodynamics of slender wings

The 'Vortex Flap' is a novel concept aimed at reducing the lift-dependent drag due to leading-edge flow separation on highly swept, slender wings at high angles of attack. The suction effect of coiled vortices generated via controlled separation over leading-edge flap surfaces is utilized to produce an aerodynamic thrust component. This principle was verified through wind-tunnel experiments on 74-deg and 60-deg delta wings and a supersonic-cruise slender wing aircraft configuration. Adaptation of the vortex-flap for augmentation of roll-control on the 74-deg delta at high angles of attack also was demonstrated. Selected results are presented in this paper to indicate the potential of the vortex flap concept to enhance the low-speed performance, stability and control of slender wing aircraft.

Rao, D. M.↗
NASA NTRS1980

Dynamic characteristics of a high-speed rotor with radial and axial foil-bearing supports

An asymmetric rotor (19N; 4.3 lb), supported radially and axially by compliant bearings is subjected to severe excitation by rotating unbalance in the 'pitching' mode at speeds to 50,000 rpm. The resilient, air-lubricated bearings provide very effective damping, so that regions of resonance and instability can be traversed with amplitudes and limit-trajectories within acceptable bounds. A novel journal bearing is introduced, in which a resilient support is furnished by the outer turn of the coiled foil-element bent to form an open polygon. The experimental apparatus and procedure are described, and the response of the rotor and flexible support system are documented by oscilloscope records of motion.

Licht, L.↗
NASA NTRS1981

Recent work on an RF ion thruster

Preliminary results of an RF ion thruster using an immersed coupler in an argon discharge are presented. Conventional ion accelerator optics are used to extract an ion beam. An account is given of the operation of an unoptimized thruster over a range of input powers, propellant flow rates, frequencies, and magnetic field strengths. It is noted that lifetime and overall efficiency factors have not yet been extensively investigated. The results obtained establish the feasibility of this approach and the potential for future improvements. The conical coil employed to couple RF power into the discharge is placed inside the discharge vessel. The discharge is self-sustained by 100-150 MHz RF power at low environmental pressures (approximately 0.00001 torr). The ion extraction is accomplished by conventional accelerator grid optics from an unoptimized 8 cm diameter ion thruster.

Lee, R. Q.↗
NASA NTRS1981

Magnetically induced cylindrical stress waves in a thermoelastic conductor

The problem of stress wave generation in a linear thermoelastic solid by a pulsed magnetic field is investigated both analytically and experimentally for a cylindrically symmetric conducting solid. A dynamic response analysis is developed to correlate magnetic, thermal, and stress fields in the solid with the time history of the electric current. In the experiment, a transient magnetic field was applied normal to a large conducting plate with a circular hole. Initially the field was confined to the interior of the circular hole. The field was generated by discharging a large capacitor bank through a solenoidal coil. The plane-stress cylindrical stress waves are 1-D in nature. The relative effects of the magnetic body force and thermoelastic stresses, both generated by the electromagnetic field, are assessed.

Chian, C. T.↗
NASA NTRS1981

On-line structural parameter identification

Algorithms are presented for on-line parameter identification of structural dynamic systems. As an example, they are used to calculate the parameters of a modal model of a flexible beam. The algorithms are tested using hardware consisting of a 12 ft. beam with four voice coil actuators and nine noncontacting displacement sensors. They are programmed in a CDC Cyber 175 digital computer which provides input command signals for the actuators, reads the sensor data, and processes the algorithm to calculate consistent estimates of the modal parameters of the beam. Experimental results are compared with those of simulation analysis.

Thau, F. E.↗
NASA NTRS1982

Scanning Seismic Intrusion Detector

Scanning seismic intrusion detector employs array of automatically or manually scanned sensors to determine approximate location of intruder. Automatic-scanning feature enables one operator to tend system of many sensors. Typical sensors used with new system are moving-coil seismic pickups. Detector finds uses in industrial security systems.

Lee, R. D.↗
NASA NTRS1982

Robot End Effector To Place and Solder Solar Cells

Encapsulated in robot end effector is RF induction-heating coil for heating solar cell while in transit. Holes in encapsulant permit end of unit to act as vacuum pickup to grip solar cell. Use of RF induction heating allows cell to be heated without requiring direct mechanical and thermal contact of bonding tool such as soldering iron.

Hagerty, J. J.↗
NASA NTRS1983

Implantable Drug Dispenser

Drugs such as insulin are injected as needed directly into bloodstream by compact implantable dispensing unit. Two vapor cavities produce opposing forces on drug-chamber diaphragm. Heaters in cavities allow control of direction and rate of motion of bellows. Dispensing capsule fitted with coil so batteries can be recharged by induction.

Collins, E. R. J.↗
NASA NTRS1983

Phase-Sensing Guidance for Wire-Following Vehicles

Guidance system for wire-following vehicles tested successfully at speeds exceeding 50 mi/h (80 km/h) on difficult 1 mile (1.6km) course. Unlike previous sensors that compare amplitudes of signals picked up from guide wire, new system compares signal phases. Array of coils is mounted in line along front bumper of vehicle and monitors electromagnetic signal radiating from wire. Guide wire on ground beneath vehicle carrier 6- to 7-kHz alternating current.

Hansen, G. R.↗
NASA NTRS1981

MAGSAT: Vector magnetometer absolute sensor alignment determination

A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

Acuna, M. H.↗
NASA NTRS1980

Spacecraft charging technology in the satellite X-ray test facility

A satellite X-ray test facility (SXTF) is planned for studying system generated electromagnetic pulse effects on full scale, operational spacecraft. The environment created by a distant, high altitude nuclear burst can be simulated using pulsed X-ray sources. The facility is to be installed in a thermal vacuum chamber with dimensions greater then 10 m diameter and 20 m height and equipped with solar simulators and equipment for simulating the charging environment of space. The spacecraft charging system consists of several low energy electron and hydrogen ion sources (5-25 keV), one or two medium energy electron accelerators (150-300 keV), an array of vacuum ultraviolet lamps, and geomagnetic field suppression coils. Military, scientific, and commercial spacecraft can be tested before launching into the radiation environment of space. construction of SXTF is scheduled to begin in 1982 and the facility should be available for general use in 1984. Potential users are encouraged to express their needs for specific testing environments in SXTF.

Sponaugle, T. J.↗
NASA NTRS1981

Passive components for high temperature operation

The development of resistors, capacitors, and interconnect metalizations utilizing a low pressure chemical vapor deposition (LPCVD) process is described. The LPCVD process allows the passive components to be fabricated at temperatures higher than their highest operating temperatures. The deposition of thin films by LPCVD is accomplished by reacting one or more gases on the surface of a heated substrate. The substrates to be coated are placed on a graphite susceptor and then loaded into the center of a quartz reaction tube. The RF power is applied to the coil on the outside of the reaction tube which in turn is coupled into the graphite susceptor causing it to heat. Pressures of several torr or less are typical, with carrier flow rates of 0.1 to 2.0 liters/min. Nitrogen, hydrogen, and helium are typical carrier gases. These are controlled with mass flow controllers and the pressure is continuously monitored with a capacitive manometer. Materials selection and device testing are also discussed.

Raymond, L. S.↗
NASA NTRS1981

High temperature (Al2O3) insulation and light weight conductors

The of an aluminum conductor with an aluminum oxide insulation film was investigated. Aluminum oxide insulated wire or strip (with a melting point of 2050 C) is unique for applications in the electronic, missile, atomic reactor, aerospace, and aircraft industries. The oxide film is highly flexible, suitable for all windings of any size and shape of coil (magnetic). Briefly touched upon are the ultraviolet, proton gamma radiation uses, as well as high vacuum and cryogenic applications. Since the film is inorganic and chemically inert, it does not age or deteriorate in storage and has good dielectric properties (1000 volts per mil).

Walker, H.↗
NASA NTRS1981

Constance mirror program: Progress and plans

The current state of the mechanics of the Constance II experiment, the physics results gathered, the motivation background, and future plans for the Constance II experiment are reviewed. Several improvements have been made and several experimental investigations have been completed. These include the construction/installation/testing of: (1) liquid-nitrogen cooled, Ioffe bars installed, (2) a diverter coil (3) the 100 kW ICRF generator, (4) the data acquisition system, and (5) the optimum hot-iron operation of the machine with Titanium and pulsed-gas plasma guns. Measurements were made of the density, temperature, and radius of the plasma. Ion-cyclotron fluctuations were observed, their bandwidth measured, and data collected demonstrating resonance heating. New X-ray diagnostics were designed and purchased, and progress on the Thomson scattering was made. Finally, a new hot cathode gun was designed and constructed.

Klinkowstein, R. E.↗