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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Technical feasibility study for the development of a large capacity wind powered electrical generating system

The engineering feasibility of developing a basic mechanical system necessary for extracting large amounts of power (on the order of 10 to 20 MW) from the wind is considered using the concept of vertical airfoils moving along a closed horizontal track system. Attention is focused on those components necessary for the conversion of wind energy to mechanical energy, although the general characteristics and critical aspects of other components are also considered. The four phases of this program are: (1) Establishment of component specifications and interface requirements for major system components; (2) formulation of alternative sets of conceptual designs for major system components; (3) engineering analysis of various components and systems; and (4) re-examination of basic concept and identification of any desirable follow-up work.

Powe, R. E.↗
NASA NTRS1975

Electrical Distribution System (EDS) and Caution and Warning System (CWS)

An astronaut caution and warning system is described which monitors various life support system parameters and detects out-of-range parameter conditions. The warning system generates a warning tone and displays the malfunction condition to the astronaut along with the proper corrective procedures required.

Mcclung, T.↗
NASA NTRS1978

Proceedings of Small Power Systems Solar Electric Workshop. Volume 2: Invited papers

The focus of this work shop was to present the committment to the development of solar thermal power plants for a variety of applications including utility applications. Workshop activities included panel discussions, formal presentations, small group interactive discussions, question and answer periods, and informal gatherings. Discussion on topics include: (1) solar power technology options; (2) solar thermal power programs currently underway at the DOE, JPL, Electric Power Research Institute (EPRI), and Solar Energy Research Institute (SERI); (3) power options competing with solar; (4) institutional issues; (5) environmental and siting issues; (6) financial issues; (7) energy storage; (8) site requirements for experimental solar installations, and (9) utility planning.

Ferber, R.↗
NASA NTRS1980

Concept definition study of small Brayton cycle engines for dispersed solar electric power systems

Three first-generation Brayton cycle engine types were studied for solar application: a near-term open cycle (configuration A), a near-term closed cycle (configuration B), and a longer-term open cycle (configuration C). A parametric performance analysis was carried out to select engine designs for the three configurations. The interface requirements for the Brayton cycle engine/generator and solar receivers were determined. A technology assessment was then carried out to define production costs, durability, and growth potential for the selected engine types.

Six, L. D.↗
NASA NTRS1980

Military markets for solar thermal electric power systems

The Department of Defense maintains an inventory of over 1,800 MW of engine-generators 15 KW and larger, with an estimated procurement rate of over 140 MW/year. Nearly the entire requirement could be met by advanced heat engines of the types being developed as point-focussing, distributed receiver power plants. A conceptual system consisting of a heat engine which efficiently burns liquid fossil or synthetic fuels, with a 'solarization kit' for conversion to hybrid solar operation could meet existing DOD requirements for new systems which are quieter, lighter, and multi-fueled. An estimated 24 percent (33 MW/year) or more could operationally benefit from the solar option. Baseline cost projections indicate levelized energy cost goals of 210 to 120 mills/KWh (15 to 1000 KW systems). Fuel cost escalation is the major factor affecting the value of the solar option. A baseline calculation for fuel at $0.59/gal in spring, 1979, escalating at 8 percent above general inflation indicates a value of $2700/KWe for a solarization kit.

Hauger, J. S.↗
NASA NTRS1980

A study of mass production and installation of small solar thermal electric power systems

Technological constraints, materials availability, production capacity, and manufacturing and installations plans and costs at different production levels are included in a study of concentrating collector industrialization. As cobalt for the engine and receiver is supply limited, alternative lower temperature alloys and higher temperature materials such as ceramics are discussed. Economics and production efficiency favor co-location of cellular and thin glass production for reflectors. Assembly and installation are expensive for small sites and few alternatives exist to apply mass production techniques to lower these costs for the selected design. Stepping motors in the size and quantities required are not commercially available today but could be in the future.

Butterfield, J. F.↗
NASA NTRS1980

Design study of a kinematic Stirling engine for dispered solar electric power systems

The concept evaluation shows that the four cylinder double acting U type Stirling engine with annular regenerators is the most suitable engine type for the 15 kW solar application with respect to design, performance and cost. Results show that near term performance for a metallic Stirling engine is 42% efficiency. Further improved components show an impact on efficiency of the future metallic engine to 45%. Increase of heater temperature, through the introduction of ceramic components, contribute the greatest amount to achieve high efficiency goals. Future ceramic Stirling engines for solar applications show an efficiency of around 50%.

Source record↗
NASA NTRS1981

Flight performance of the Voyager electrical power system

The Voyager power subsystem is described, and its flight performance to date is discussed. Special attention is given to the performance of the primary power source radioisotope thermoelectric generators (RTGs), to the autonomous operation features of the power system, and to the load management strategy developed to maintain an adequate power margin during application of transient loads and as normal degradation reduces RTG capability. It is found that the flight performance of the power system has been without significant problems to date and that RTG performance has exceeded mission requirements.

Packard, L. A.↗
NASA NTRS1981

The electric Orbiter

An electromechanical actuator (EMA) system is described and compared to the baseline hydraulic system for the Shuttle. Employment of the EMA depends on minimal changes in the avionics and software, no change in the vehicle configuration, and satisfaction of performance requirements. There are 13 actuators on the Shuttle, all subject to the standard four (redundant) command channels. The actuator control units, motor control units, mechanical actuators, and motors are discussed, and system and sizing requirements are outlined. The effects on the displays and controls, the environmental control system, electrical power and distribution, and software are mentioned, and projected to be minimal. It is noted that although the EMA total systems' costs have not been calculated, substantial weight, turnaround time, and power savings are available by use of EMA.

Swingle, W. L.↗
NASA NTRS1981

Solar electric propulsion system /SEPS/: Tomorrow's propulsion system - Today

Mission and system concepts relating to the SEPS project will be discussed as well as an overview of current project planning. SEPS system concept descriptions will be limited to in-house NASA concepts. The capabilities of the in-house concepts to meet a wide range of mission requirements will be described to give an indication of potential capabilities SEPS can provide to the space mission planners.

Austin, R. E.↗
NASA NTRS1982

Multiple and variable speed electrical generator systems for large wind turbines

A cost effective method to achieve increased wind turbine generator energy conversion and other operational benefits through variable speed operation is presented. Earlier studies of multiple and variable speed generators in wind turbines were extended for evaluation in the context of a specific large sized conceptual design. System design and simulation have defined the costs and performance benefits which can be expected from both two speed and variable speed configurations.

Andersen, T. S.↗
NASA NTRS1982

Evaluation of solid oxide fuel cell systems for electricity generation

Air blown (low BTU) gasification with atmospheric pressure Solid Electrolyte Fuel Cells (SOFC) and Rankine bottoming cycle, oxygen blown (medium BTU) gasification with atmospheric pressure SOFC and Rankine bottoming cycle, air blown gasification with pressurized SOFC and combined Brayton/Rankine bottoming cycle, oxygen blown gasification with pressurized SOFC and combined Brayton/Rankine bottoming cycle were evaluated.

Somers, E. V.↗
NASA NTRS1983

Design considerations for large space electric power systems

As power levels of spacecraft rise to the 50 to 100 kW range, it becomes apparent that low voltage (28 V) dc power distribution and management systems will not operate efficiently at these higher power levels. The concept of transforming a solar array voltage at 150 V dc into a 1000 V ac distribution system operating at 20 kHz is examined. The transformation is accomplished with series-resonant inverter by using a rotary transformer to isolate the solar array from the spacecraft. The power can then be distributed in any desired method such as three phase delta to delta. The distribution voltage can be easily transformed to any desired load voltage and operating frequency. The reasons for the voltage limitations on the solar array due to plasma interactions and the many advantages of a high voltage, high frequency at distribution system are discussed.

Renz, D. D.↗