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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 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Logic-controlled solid state switchgear for 270 volts dc

A feasibility study to design and demonstrate solid state switchgear in the form of circuit breakers and a power transfer switch is described. The switchgear operates on a nominal 270 V dc circuit and controls power to a load of up to 15 amperes. One circuit breaker may be interconnected to a second breaker to form a power transfer switch. On-off and transfer functions of the breakers or the transfer switch are remotely controlled. A number of reclosures with variable time delay between tripout and reclosure are programmed and controlled by integrated analog and COSMOS logic circuits. A unique commutation circuit, that generates only minimal transient disturbance to either source or load, was developed to interrupt current flow through the main SCR switching element. Laboratory tests demonstrated performance of the solid state circuit breakers over specified voltage and temperature ranges.

Sundberg, G. R.↗
NASA NTRS1972

Design and fabricate a pair of Rancho anthropomorphic manipulator arms

The basic design features of the Rancho Anthropomorphic Manipulator (RAM), bilateral manipulator system are reported. In contrast with other previous electrically powered manipulators, the RAM features increased payload capability, structural integrity, position control, and the ability to interchange its own terminal devices. A set of detailed design drawings and a motion picture are considered.

Allen, J. R.↗
NASA NTRS1975

Analysis of longitudinal pilot-induced oscillation tendencies of YF-12 aircraft

Aircraft flight and ground tests and simulator studies were conducted to explore pilot-induced oscillation tendencies. Linear and nonlinear calculations of the integrated flight control system's characteristics were made to analyze and predict the system's performance and stability. The investigations showed that the small-amplitude PIO tendency was caused by the interaction of the pilot with a combination of the aircraft's short-period poles and the structural first bending mode zeros. It was found that the large-amplitude PIO's were triggered by abrupt corrective control actions by the pilot, which caused the stability augmentation system servo to position and rate limit. The saturation in turn caused additional phase lag, further increasing the tendency of the overall system to sustain a PIO.

Smith, J. W.↗
NASA NTRS1975

Design synthesis of the SEPS

This paper summarizes the most current configuration of the Solar Electric Propulsion Stage (SEPS) design resulting from the synthesis of key tradeoff analyses. The baseline SEPS is a 21-kW propulsion-power vehicle using the Shuttle/Interim Upper Stage (IUS) launch vehicle for planetary and geosynchronous missions. The trade analyses supporting the baseline configuration include ion thruster array pattern, solar array stowage concepts, and number of thrusters and power processors (PP). In addition, an integrated thermal control and structural system was optimized and designed to meet flight loads and dynamics requirements. Payload provisions, mercury propellant refueling, and design compatibility of the SEPS and Shuttle/IUS are presented.

Horio, S. P.↗
NASA NTRS1976

Design, processing, and testing of LSI arrays for space station

The work on the Process Analysis Structure was continued with the layout being completed, the 100X and 10X artwork being finalized, and the process and test sequences being prepared. Test programs were written for computer-controlled integrated-circuit testing and data reduction.

Ipri, A. C.↗
NASA NTRS1976

IPCS implications for future supersonic transport aircraft

The Integrated Propulsion Control System (IPCS) demonstrates control of an entire supersonic propulsion module - inlet, engine afterburner, and nozzle - with an HDC 601 digital computer. The program encompasses the design, build, qualification, and flight testing of control modes, software, and hardware. The flight test vehicle is an F-111E airplane. The L.H. inlet and engine will be operated under control of a digital computer mounted in the weapons bay. A general description and the current status of the IPCS program are given.

Billig, L. O.↗
NASA NTRS1976

Low-frequency noise reduction of lightweight airframe structures

The results of an experimental study to determine the noise attenuation characteristics of aircraft type fuselage structural panels were presented. Of particular interest was noise attenuation at low frequencies, below the fundamental resonances of the panels. All panels were flightweight structures for transport type aircraft in the 34,050 to 45,400 kg (75,000 to 100,000 pounds) gross weight range. Test data include the results of vibration and acoustic transmission loss tests on seven types of isotropic and orthotropically stiffened, flat and curved panels. The results show that stiffness controlled acoustically integrated structures can provide very high noise reductions at low frequencies without significantly affecting their high frequency noise reduction capabilities.

Getline, G. L.↗
NASA NTRS1978

The present situation and forecasts of semiconductor elements performance within the microwave range, 1970-1985

The present situation and possible developments over the period 1970-1985 for active semiconductor elements in the microwave range are outlined. After a short historical survey of FT techniques, the following are discussed: Generation, power amplification, amplification of small signals, frequency conversion, detection, electronic signal control and integrated microwave circuits.

Peterson, B.↗
NASA NTRS1979

A Demonstration Advanced Avionics System for general aviation

A program initiated within NASA has emphasized the use of a data bus, microprocessors, electronic displays and data entry devices for general aviation. A Demonstration Advanced Avionics System (DAAS) capable of evaluating critical and promising elements of an integrating system that will perform the functions of (1) automated guidance and navigation; (2) flight planning; (3) weight and balance performance computations; (4) monitoring and warning; and (5) storage of normal and emergency check lists and operational limitations is described. Consideration is given to two major parts of the DAAS instrument panel: the integrated data control center and an electronic horizontal situation indicator, and to the system architecture. The system is to be installed in the Ames Research Center's Cessna 402B in the latter part of 1980; engineering flight testing will begin in the first part of 1981.

Denery, D. G.↗
NASA NTRS1979

Development of mining guidance and control systems

New fundamental interface sensor concepts were identified and investigated including tabulation of the physical and performance characteristics of two new interface detector concepts: - natural background radiation and magnetic spin resonance. Studies of guidance and control techniques for the longwall miner identified three basic systems for use in automated/remote controlled longwall mining. The following projects were initiated: system study which will more completely define the longwall guidance and control system design concepts; integration of the various control functions (vertical, yaw, and roll); and hardware technical requirements.

Source record↗
NASA NTRS1979

Manufacturing methods of a composite cell case for a Ni-Cd battery

Basic manufacturing method refinements for using graphite epoxy material for a nickel cadmium battery cell case were performed to demonstrate production feasibility. The various facets of production scale-up, i.e., process and tooling development, together with material and process control, were integrated into a comprehensive manufacturing process that assures production reproducibility and product uniformity. Test results substantiate that a battery cell case produced from graphite epoxy pre-impregnated material, utilizing the internal pressure bag fabrication method, is feasible.

Bauer, J. L.↗
NASA NTRS1979

Applying integrals of motion to the numerical solution of differential equations

A method is developed for using the integrals of systems of nonlinear, ordinary differential equations in a numerical integration process to control the local errors in these integrals and reduce the global errors of the solution. The method is general and can be applied to either scaler or vector integrals. A number of example problems, with accompanying numerical results, are used to verify the analysis and support the conjecture of global error reduction.

Jezewski, D. J.↗
NASA NTRS1980

Applying integrals of motion to the numerical solution of differential equations

A method is developed for using the integrals of systems of nonlinear, ordinary, differential equations in a numerical integration process to control the local errors in these integrals and reduce the global errors of the solution. The method is general and can be applied to either scalar or vector integrals. A number of example problems, with accompanying numerical results, are used to verify the analysis and support the conjecture of global error reduction.

Vezewski, D. J.↗
NASA NTRS1980

Pressure control valve

A control valve is provided which is adapted to be connected between a pressure source, such as a vacuum pump, and a pressure vessel so as to control the pressure in the vessel. The valve comprises a housing having a longitudinal bore which is connected between the pump and vessel, and a transversely movable valve body which controls the air flow through an air inlet in the housing. The valve body includes cylindrical and conical shaped portions which cooperate with reciprocally shaped portions of the housing to provide flow control. A filter in the air inlet removes foreign matter from the air. The bottom end of the valve body is screwed into the valve housing control knob formed integrally with the valve body and controls translation of the valve body, and the opening and closing of the valve.

Lambson, K. H.↗
NASA NTRS1980

Demonstration Advanced Avionics System (DAAS) functional description

A comprehensive set of general aviation avionics were defined for integration into an advanced hardware mechanization for demonstration in a Cessna 402B aircraft. Block diagrams are shown and system and computer architecture as well as significant hardware elements are described. The multifunction integrated data control center and electronic horizontal situation indicator are discussed. The functions that the DAAS will perform are examined. This function definition is the basis for the DAAS hardware and software design.

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NASA NTRS1981

In-mine testing of a natural background sensor, part B

The capability of a natural background sensor for measuring the thickness of top coal on a longwall face was examined. The limitations on the time during which tests could be performed, and the roof conditions, did not produce readings of top coal measurements during the shearer operation. It was demonstrated that the system is capable to survive operating conditions in the mine environment, while the static tests confirmed that the natural background sensor approach is a valid method of measuring top coal thickness in mines where the roof rock provides a constant radiation level. It is concluded that the practical results will improve sequent development of an integrated vertical control system which is information from the natural background system.

Martzloff, F. D.↗
NASA NTRS1981

Effects of photometric geometry on spectral reflectance measurements

Progress is reported in obtaining valuable results needed for the full interpretation of the spectral reflectance curves of solar system objects. The degree to which photometric geometry affects spectral reflectance curves was demonstrated. Various forms of photometric functions were compared and a function adequate for describing the scattering properties of low and moderately reflecting materials was developed and applied in a study of the phase coefficients of various materials, as well as in a study of how the shape of a body affects the spectral reflectance properties. The adequacy of the photometric function for Mars-like analogs was studied. The goniometer system is being converted to a computer driven mode. As soon as computer controls are integrated in the goniometer, the phase dependence 0.95 micron feature in meteorite spectra is scheduled to begin.

Veverka, J.↗