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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 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 NTRS1978

Description and status of NASA-LeRC/DOE photovoltaic applications systems experiments

In its role of supporting the DOE Photovoltaic Program, the NASA-Lewis Research Center has designed, fabricated and installed 16 geographically dispersed photovoltaic systems. These systems are powering a refrigerator, highway warning sign, forest lookout towers, remote weather stations, a water chiller at a visitor center, and insect survey traps. Each of these systems is described in terms of load requirements, solar array and battery size, and instrumentation and controls. Operational experience is described and present status is given for each system. The P/V power systems have proven to be highly reliable with almost no problems with modules and very few problems overall

Ratajczak, A. F.↗
NASA NTRS1981

Predicting and monitoring duststorms

Information on duststorms is processed by terminal receiving signals from two geosynchronous satellites. Data is correlated with that of other agencies to produce color maps depicting storm area. Series of maps reveals storm direction, warning regions up to 24 hours before they are struck.

Woiceshyn, P. M.↗
NASA NTRS1979

Needed weather information where it belongs; in the cockpit

The availability of inflight weather data to the cockpit is discussed. The need for real-time information systems to warn of hazardous weather conditions is emphasized. It is suggested that the Weather Service severe weather radar network be collocated with the FAA radar to provide information for real-time decision making.

Gatlin, H. G.↗
NASA NTRS1979

Solar-terrestrial Predictions Proceedings. Volume 1: Prediction Group Reports

The current practice in solar terrestrial predictions is reviewed with emphasis of prediction, warning, and monitoring services. Topics covered include: ionosphere-reflected HF radio propagation; radiation hazards for manned space flights and high altitude and high latitude aircraft flights; and geomagnetic activity.

Donnelly, R. F.↗
NASA NTRS1979

KAZIA: A computer system for solar-terrestrial data processing and objective prediction

A computer system for solar terrestrial data processing is described. The data base consists mainly of information contained in Ursigrams exchanged between the IUWDS Regional Warning Centers. The system structure and its functions are presented. Solar flare forecasting is described, as one of the prediction techniques incorporated in the system.

Stasiewicz, K.↗
NASA NTRS1979

A disturbance forecaster's view of the September 1977 events

The solar-geophysical events of 1977 September 7-26 are presented. A variety of disturbance forecasting problems, viz, disc transit of a center of activity with high microwave flux but relatively low meter-wave flux, flares in this region near east limb, central meridian, and west limb with major radio events, and the presence of two coronal holes, were observed. The Sydney daily GEOSYD message and IPS Disturbance Warnings issued during this period are related to the solar geophysical data available, at the time, about these events.

Cook, F. E.↗
NASA NTRS1979

The problem of solar induced currents

The production of surface electric fields by geomagnetic variations is discussed with reference to magnetotelluric theory; and evidence is presented to show that the severity of solar-induced currents (SIC) at Cornerbrook, Newfoundland is due to channeling of currents induced in the sea through a region adjacent to the power line. An 'isolated loop' approximation is proposed for calculating the quasi-dc currents produced in the power system by the surface electric fields. Identification of the processes causing the geomagnetic perturbations responsible for SIC would be aided by investigation of the local time dependence of SIC occurrence. Such knowledge could potentially be used to provide several hours warning of SIC.

Boteler, D. H.↗
NASA NTRS1979

D region predictions

Present knowledge of D region phenomena is briefly reviewed and the status of current methods of predicting their effects on radio propagation considered. The ELF, VLF and LF navigational and timing systems depend on the stability of the lower part of the D layer where these waves are reflected, whereas MF and HF waves are absorbed as they penetrate the region, in most cases mainly in the upper part of the layer. Possible methods of improving predictions, warnings, and real time operations are considered with particular stress on those which can be implemented in the near future.

Thrane, E. V.↗
NASA NTRS1982

Pressure Switch Is a Low Cost Battery Indicator

Conventional pressure switch, fabricated by printed-circuit manufacturing techniques, can indicate when charge on battery departs from preset level. Membrane on switch is exposed to internal pressure of battery, which varies according to stored charge. When pressure varies from preset level, switch can turn on a light-emitting diode or similar indicator to warn user that battery is low.

Abita, J. L.↗
NASA NTRS1980

Solar photovoltaics: Stand alone applications

The Lewis Research Center involvement in space photovoltaic research and development and in using photovoltaics for terrestrial applications is described with emphasis on applications in which the normal source of power may be a diesel generator, batteries, or other types of power not connected to a utility grid. Once an application is processed, technology is developed and demonstrated with a user who participates in the cost and furnishes the site. Projects completed related to instruments, communication, refrigeration, and highways, are described as well as warning systems, weather stations, fire lookouts, and village power systems. A commercially available photovoltaic powered electric fence charger is the result of Lewis research and development.

Deyo, J. N.↗
NASA NTRS1980

The microburst: Common factor in recent aircraft accidents

The phenomenology of one class of strong thunderstorm downdrafts, microbursts, is described. Several aircraft accidents are analyzed in which a microburst was involved and a concept for an early warning wind shear sensor is presented.

Caracena, F.↗
NASA NTRS1980

Triple redundant hydrogen sensor with in situ calibration

To meet sensing and calibration needs, an in situ calibration technique was developed. It is based on electrolytic generation of a hydrogen/air atmosphere within a hydrogen sensor. The hydrogen is generated from water vapor in the air, and being electrical in nature, the in situ calibration can be performed completely automatically in remote locations. Triply redundant sensor elements are integrated within a single, compact housing, and digital logic provides inter-sensor comparisons to warn of and identify malfunctioning sensor elements. An evaluation of this concept is presented.

Lantz, J. B.↗
NASA NTRS1981

The 1979 Clear Air Turbulence Flight Test Program

The flight experiments for clear air turbulence (CAT) detection and measurement concepts are described. The test were conducted over the western part of the United States during the winter season of 1979 aboard NASA's Galileo 2 flying laboratory. A carbon dioxide pulsed Doppler lidar and an infrared radiometer were tested for the remote detection and measurement of CAT. Two microwave radiometers were evaluated for their ability to provide encounter warning and altitude avoidance information.

Weaver, E. A.↗
NASA NTRS1981

Clear air turbulence studies with microwave radiometers

The flight testing of two passive microwave radiometers for the detection of clear air turbulence (CAT) is discussed. A 55.3 GHz radiometer was used to measure altitude temperature profiles, and a 180 GHz radiometer was used for monitoring line-of-sight integrated water vapor content. The sequence of altitude temperature profiles, spaced 17 seconds apart (3.5 km), enable inversion layer and tropopause properties to be studied. On some occasions, the altitude distribution of CAT severity correlated well with inversion layer location. On other occasions, turbulence was not located within 55.3 GHz measured layers, possibly indicating cases of topography-generated CAT, where inversion layer would not necessarily be expected. Evidence was obtained supporting the hypothesis that CAT is generated within layers containing levels of wind shear that cannot be supported by the layer's lapse rate; i.e., that Kelvin-Helmholtz wave breakdown can generate CAT. The 180 GHz radiometer failed to warn of CAT events. It is suggested that the radiometer's sensitivity (1 K) was inadequate for detecting the small variations in line-of-sight water vapor content.

Gary, B. L.↗
NASA NTRS1981

Lightning accommodation systems for wind turbine generator safety

The wind turbine safety program identifies the naturally occurring lightning phenomenon as a hazard with the potential to cause loss of program objectives, injure personnel, damage system instrumentation, structure or support equipment and facilities. Several candidate methods of lightning accommodation for each blade were designed, analyzed, and tested by submitting sample blade sections to simulated lightning. Lightning accommodation systems for composite blades were individually developed. Their effectiveness was evaluated by submitting the systems to simulated lightning strikes. The test data were analyzed and system designs were reviewed on the basis of the analysis. This activity is directed at defining design and procedural constraints, requirements for safety devices and warning methods, special procedures, protective equipment and personnel training.

Bankaitis, H.↗