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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 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Design of a mercury Propellant Storage and Distribution assembly

A study has been conducted of a Propellant Storage and Distribution (PSD) assembly for a solar electric propulsion (SEP) thrust subsystem. As a result of the trade-off study an elastomeric diaphragm propellant tank with nitrogen blowdown pressurization was the method selected for propellant expulsion. This study included the following propellant management devices: surface tension, metallic bellows, and metallic and elastomeric diaphragms. Pressurant supply concepts investigated were blowdown, externally pressure regulated, vaporizing Freon 113, and heated CO2/Zeolite. The configuration selected consists of a single propellant tank, a single main propellant latching-solenoid valve, and individual thruster latching-solenoid valves. Stainless steel was the selected tankage material and AF-E-332 was the selected diaphragm material. The PSD design characteristics and interfaces are summarized.

Holcomb, L. B.↗
NASA NTRS1974

Pulse-modulated dual-gas control subsystem for space cabin atmosphere

An atmosphere control subsystem (ACS) was developed for use in a closed manned cabin, such as the Space Shuttle Orbiter. This subsystem uses the Perkin Elmer mass spectrometer for continuous measurement of major atmospheric constituents (H2, H2O, N2, O2, and CO2). The O2 and N2 analog signals are used as inputs to the controller, which produces a pulse-frequency-modulated output to operate the N2 gas admission solenoid valve and an on-off signal to operate the O2 valve. The proportional controller characteristic results in improved control accuracy as compared with previously used on-off controllers having significant dead-band. A 60-day evaluation test was performed on the ACS during which operation was measured at various values of control setpoint and simulated cabin leakage.

Jackson, J. K.↗
NASA NTRS1975

Regulator for intravenous feeding

Float valve maintains constant level of solution, providing constant drop rate as long as solution can flow into patient's vein. Second float valve allows solution to enter vein, but prevents entry of air.

Dimeff, J.↗
NASA NTRS1974

Automatically operable self-leveling load table

A self-leveling load table is described which is automatically maintained level by selectively opening and closing solenoid valves for inserting and removing air from chambers under the table. The table is floated in a fluid by nine air chambers beneath the top of the table. These chambers are open at the bottom and four oppositely located chambers are used for leveling the table by having the air increased or decreased by means of a flexible hose. Air bearing pendulums are used for selectively energizing solenoid valves which either apply pressurized air to the chamber or evacuate air from the chamber by means of a vacuum source.

Burch, J. L.↗
NASA NTRS1977

Hologram-reconstruction signal enhancement

Principle of heterodyne detection is used to combine object beam and reconstructed virtual image beam. All light valves in page composer are opened, and virtual-image beam is allowed to interfere with light from valves.

Mezrich, R. S.↗
NASA NTRS1975

SSME-HAS dynamic load simulators

The space shuttle main engine propellant valve actuators (SSME) were designed to simulate the loads reflected into the SSME by the chamber coolant valve, the fuel preburner, and the oxidizer. The design, and functional description are included along with a list of the drawings. The load fixture control transform, friction torque, and flow calculations are reported.

Source record↗
NASA NTRS1975

Optical-to-optical interface device

An investigation was conducted to develop an optical-to-optical interface device capable of performing real-time incoherent-to-incoherent optical image conversion. The photoactivated liquid crystal light valve developed earlier represented a prototype liquid crystal light valve device capable of performing these functions. A device was developed which had high performance and extended lifetime.

Jacobson, A. D.↗
NASA NTRS1975

Vapor-modulated heat pipe report. Flight data analysis and further development of variable-conductance heat pipes

The design and testing of a heat pipe for spacecraft application is presented. The application in mind calls for heat loads up to 20 watts, a set-point temperature of 294K, and a sink that varies from -220K to nearly as high as the set-point. The overall heat pipe length is 137 cm. Two basically different mechanisms of achieving variable conductance in the pipe by vapor-flow throttling were studied. In one, the thermal resistance between the heat source and sink is due to a saturation-temperature drop corresponding to the vapor-pressure drop developed across the valve. In the other, the pressure difference across the valve induces capillary groove and wick dry out in an evaporation region, and thus results in an increased thermal resistance. This mechanism was selected for fabrication and testing. The pipe is a stainless-steel/methanol two-heat-pipe system. Results are presented and discussed. Engineering drawings and specifications of the pipe are shown.

Eninger, J. E.↗
NASA NTRS1976

Preliminary input to the space shuttle reaction control subsystem failure detection and identification software requirements (uncontrolled)

The current baseline method and software implementation of the space shuttle reaction control subsystem failure detection and identification (RCS FDI) system is presented. This algorithm is recommended for conclusion in the redundancy management (RM) module of the space shuttle guidance, navigation, and control system. Supporting software is presented, and recommended for inclusion in the system management (SM) and display and control (D&C) systems. RCS FDI uses data from sensors in the jets, in the manifold isolation valves, and in the RCS fuel and oxidizer storage tanks. A list of jet failures and fuel imbalance warnings is generated for use by the jet selection algorithm of the on-orbit and entry flight control systems, and to inform the crew and ground controllers of RCS failure status. Manifold isolation valve close commands are generated in the event of failed on or leaking jets to prevent loss of large quantities of RCS fuel.

Bergmann, E.↗
NASA NTRS1975

Software for Digital Acquisition System and Application to Environmental Monitoring

Criteria for selection of a minicomputer for use as a core resident acquisition system were developed for the ODU Mobile Air Pollution Laboratory. A comprehensive data acquisition program named MONARCH was instituted in a DEC-8/E-8K 12-bit computer. Up to 32 analog voltage inputs are scanned sequentially, converted to BCD, and then to actual numbers. As many as 16 external devices (valves or any other two-state device) are controlled independently. MONARCH is written as a foreground-background program, controlled by an external clock which interrupts once per minute. Transducer voltages are averaged over user specified time intervals and, upon completion of any desired time sequence, outputted are: day, hour, minute, second; state of external valves; average value of each analogue voltage (E Format); as well as standard deviations of these values. Output is compatible with any serially addressed media.

Copeland, G. E.↗
NASA NTRS1976

Self-contained breathing apparatus

A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

Sullivan, J. L.↗
NASA NTRS1976

Computer measurement and representation of the heart in two and three dimensions

Methods for the measurement and display by minicomputer of cardiac images obtained from fluoroscopy to permit an accurate assessment of functional changes are discussed. Heart contours and discrete points can be digitized automatically or manually, with the recorded image in a video, cine, or print format. As each frame is digitized it is assigned a code name identifying the data source, experiment, run, view, and frame, and the images are filed for future reference in any sequence. Two views taken at the same point in the heart cycle are used to compute the spatial position of the ventricle apex and the midpoint of the aortic valve. The remainder of the points on the chamber border are corrected for the linear distortion of the X-rays by projection to a plane containing the chord between the apex and the aortic valve center and oriented so that lines perpendicular to the chord are parallel to the image intensifier face. The image of the chamber surface is obtained by generating circular cross sections with diameters perpendicular to the major chord. The transformed two- and three-dimensional imagery can be displayed in either static or animated form using a graphics terminal.

Rasmussen, D.↗
NASA NTRS1978

Vapor-modulated heat pipe for improved temperature control

Dryout induced by vapor throttling makes control of equipment temperature less dependent on variations in sink environment. Mechanism controls flow of vapor in heat pipe by using valve in return path to build difference in pressure and also difference in saturation temperature of the vapor. In steady state, valve closes just enough to produce partial dryout that achieves required temperature drop.

Edwards, D. K.↗
NASA NTRS1976

Liquid cooled brassiere and method of diagnosing malignant tumors therewith

A device for enhancing the detection of malignant tissue in the breasts of a woman was described. A brassiere-like garment which is fitted with a pair of liquid-perfused cooling panels which completely and compliantly cover the breasts and upper torso was studied. The garment is connected by plastic tubing to a liquid cooling system comprising a fluid pump, a solenoid control valve for controlling the flow of fluid to either the cooling unit or the heating unit, a fluid reservoir, a temperature sensor in the reservoir, and a restrictor valve to control the pressure in the garment inlet cooling line.

Elkins, W.↗
NASA NTRS1977

Oil cooling system for a gas turbine engine

A gas turbine engine fuel delivery and control system is provided with means to recirculate all fuel in excess fuel control requirements back to the aircraft fuel tank. This increases the fuel pump heat sink and decreases the pump temperature rise without the addition of valving other than normally employed. A fuel/oil heat exchanger and associated circuitry is provided to maintain the hot engine oil in heat exchange relationship with the cool engine fuel. Where anti-icing of the fuel filter is required, means are provided to maintain the fuel temperature entering the filter at or above a minimum level to prevent freezing thereof. In one embodiment, a divider valve is provided to take all excess fuel from either upstream or downstream of the fuel filter and route it back to the tanks, the ratio of upstream to downstream extraction being a function of fuel pump discharge pressure.

Coffinberry, G. A.↗
NASA NTRS1977

Gravity flow rate of solids through orifices and pipes

Lock-hopper systems are the most common means for feeding solids to and from coal conversion reactor vessels. The rate at which crushed solids flow by gravity through the vertical pipes and valves in lock-hopper systems affects the size of pipes and valves needed to meet the solids-handling requirements of the coal conversion process. Methods used to predict flow rates are described and compared with experimental data. Preliminary indications are that solids-handling systems for coal conversion processes are over-designed by a factor of 2 or 3.

Gardner, J. F.↗
NASA NTRS1977

Lock hopper values for coal gasification plant service

Although the operating principle of the lock hopper system is extremely simple, valve applications involving this service for coal gasification plants are likewise extremely difficult. The difficulties center on the requirement of handling highly erosive pulverized coal or char (either in dry or slurry form) combined with the requirement of providing tight sealing against high-pressure (possibly very hot) gas. Operating pressures and temperatures in these applications typically range up to 1600 psi (110bar) and 600F (316C), with certain process requirements going even higher. In addition, and of primary concern, is the need for reliable operation over long service periods with the provision for practical and economical maintenance. Currently available data indicate the requirement for something in the order of 20,000 to 30,000 open-close cycles per year and a desire to operate at least that long without valve failure.

Schoeneweis, E. F.↗
NASA NTRS1977

Iodine generator for reclaimed water purification

The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser.

Wynveen, R. A.↗