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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 523 records · Page 29

All sources NASA NTRS DOE OSTI

NASA NTRS1975

CARETS: A prototype regional environmental information system. Volume 13: Utility of CARETS products to local planners; an evaluation

The Metropolitan Washington Council of Governments (MWCOG) in cooperation with and under contract to the U.S. Geological Survey, conducted an evaluation of the utility of remote-sensor derived land use data produced by the USGS Central Atlantic Regional Ecological Test Site (CARETS) project. Investigators invited representatives of Washington, D.C. metropolitan area planning agencies to a workshop, introduced them to the CARETS products, and asked them to evaluate the products. In follow-up interviews, planners from 12 participating agencies reported general support for the fulI spectrum of CARETS products but gave more positive responses towards products with which they had some familiarity. Planners considered some products of limited utility because of (1) insufficient detail, (2) too small a scale, or (3) lack of technical capability to incorporate the information and products into the current planning process. Some planners expressed doubt about the application of CARETS products in most day-to-day planning activities , which involve specific rezoning requests or site development plans requiring highly localized data. The greatest potential of the CARETS products was in the identification of broad development patterns at the county or regional level. An appendix documents the results of an inventory of local government decisions relating to land use.

Land use planning↗

NASA NTRS1976

Utilization of satellite imagery by in-flight aircraft

Present and future utilization of satellite weather data by commercial aircraft while in flight was assessed. Weather information of interest to aviation that is available or will become available with future geostationary satellites includes the following: severe weather areas, jet stream location, weather observation at destination airport, fog areas, and vertical temperature profiles. Utilization of this information by in-flight aircraft is especially beneficial for flights over the oceans or over remote land areas where surface-based observations and communications are sparse and inadequate.

Luers, J. K.↗

NASA NTRS1977

Integrated payload and mission planning, phase 3. Volume 4: Optimum utilization of Spacelab racks and pallets

The methodology to optimize the utilization of Spacelab racks and pallets and to apply this methodology to the early STS Spacelab missions was developed. A review was made of Spacelab Program requirements and flow plans, generic flow plans for racks and pallets were examined, and the principal optimization criteria and methodology were established. Interactions between schedule, inventory, and key optimization factors; schedule and cost sensitivity to optional approaches; and the development of tradeoff methodology were addressed. This methodology was then applied to early spacelab missions (1980-1982). Rack and pallet requirements and duty cycles were defined, a utilization assessment was made, and several trade studies performed involving varying degrees of Level IV integration, inventory level, and shared versus dedicated Spacelab racks and pallets.

Logston, R. G.↗

NASA NTRS1977

Applications of advanced V/STOL aircraft concepts to civil utility missions, volume 1

The suitability of advanced V/STOL aircraft to civil utility applications was assessed for offshore oil support, forest fire support, transport, and humanitarian missions. The aircraft concepts considered were a lift fan aircraft, a tilt rotor aircraft, and an advanced helicopter. All the aircraft had a design payload of 2,268 kg. (5,000 lb.) with the maximum range varying from 2,224 km. (1,800 nm) for the lift fan STOL to 1,482 km (800 nm) for the advanced helicopter. The analysis of these missions considered such factors as aircraft performance, annual utilization, initial cost, and operating cost. It is concluded that all the advanced V/STOL aircraft concepts generally performed these missions better than contemporary aircraft. The lift fan aircraft and the tilt rotor aircraft were found to be effective for the offshore oil and the forest fire support missions. The lift fan aircraft in the VTOL mode was also found to be very attractive for the executive transport mission where the passenger time value was $30/hr. or more.

Source record↗

NASA NTRS1977

Study of Lyndon B. Johnson Space Center utility systems

The results of an engineering study of potential energy saving utility system modifications for the NASA Lyndon B. Johnson Space Center are presented. The objective of the study was to define and analyze utility options that would provide facility energy savings in addition to the approximately 25 percent already achieved through an energy loads reduction program. A systems engineering approach was used to determine total system energy and cost savings resulting from each of the ten major options investigated. The results reported include detailed cost analyses and cost comparisons of various options. Cost are projected to the year 2000. Also included are a brief description of a mathematical model used for the analysis and the rationale used for a site survey to select buildings suitable for analysis.

Redding, T. E.↗

NASA NTRS1975

Spectrum-orbit utilization - An overview

This paper discusses the problems associated with the efficient utilization of the natural resources of frequency spectrum and geo-stationary orbital arc. The nature of these resources is explained and their quantities are estimated. The present and projected future demand for them is given, and the problem areas are identified and discussed. Special emphasis is placed on mutual interference, launch limitations, propagation effects, and operational restrictions. The technical factors bearing on these problems, such as antenna patterns, modulation methods, emission restrictions, equipment characteristics, and system requirements, are discussed in detail. Some important trade-offs are presented, and special techniques that can be used to increase spectrum-orbit utilization are described. Particular emphasis is given throughout to U.S. domestic satellite communication systems.

Sawitz, P. H.↗

NASA NTRS1977

Ionospheric aerodynamics and space simulation studies utilizing the Shuttle/Spacelab platform

A new philosophy for the second generation of in situ experiments in the area of plasma flows over bodies is discussed. A brief review of the present state of the theory and terrestrial laboratory and in situ studies is given, which points toward the need for further in situ investigations which utilize independently maneuverable test bodies and diagnostic instrument packages on board the Shuttle/Spacelab. The possibility of utilizing the Space Shuttle/Spacelab in the broader context of a general in situ plasma laboratory is considered, as well as the possibility of addressing questions of geo/astrophysical interest if the principle of qualitative scaling is used in conjunction with such a facility.

Samir, U.↗

NASA NTRS1977

Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants

The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only 60% to 80% of peak load. As peak load increases, the present practice is to purchase power from other grid facilities or to bring older less efficient fossil-fuel plants on line which increase the cost of electric power. The widespread use of oil-fired boilers, gas turbine and diesel equipment to meet peaking loads depletes our oil-based energy resources. Heat exchangers utilizing molten salts can be used to level the energy consumption curve. The study begins with a demand analysis and the consideration of several existing modern fossil-fuel and nuclear power plants for use as models. Salts are evaluated for thermodynamic, economic, corrosive, and safety characteristics. Heat exchanger concepts are explored and heat exchanger designs are conceived. Finally, the economics of TES conversions in existing plants and new construction is analyzed. The study concluded that TES is feasible in electric power generation. Substantial data are presented for TES design, and reference material for further investigation of techniques is included.

Ferarra, A.↗

NASA NTRS1978

CAVE3: A general transient heat transfer computer code utilizing eigenvectors and eigenvalues

The method of solution is a hybrid analytical numerical technique which utilizes eigenvalues and eigenvectors. The method is inherently stable, permitting large time steps even with the best of conductors with the finest of mesh sizes which can provide a factor of five reduction in machine time compared to conventional explicit finite difference methods when structures with small time constants are analyzed over long time periods. This code will find utility in analyzing hypersonic missile and aircraft structures which fall naturally into this class. The code is a completely general one in that problems involving any geometry, boundary conditions and materials can be analyzed. This is made possible by requiring the user to establish the thermal network conductances between nodes. Dynamic storage allocation is used to minimize core storage requirements. This report is primarily a user's manual for CAVE3 code. Input and output formats are presented and explained. Sample problems are included which illustrate the usage of the code as well as establish the validity and accuracy of the method.

Palmieri, J. V.↗

NASA NTRS1978

Utilization of waste heat in trucks for increased fuel economy

Improvements in fuel economy for a broad spectrum of truck engines and waste heat utilization concepts are evaluated and compared. The engines considered are the diesel, spark ignition, gas turbine, and Stirling. The waste heat utilization concepts include preheating, regeneration, turbocharging, turbocompounding, and Rankine engine compounding. Predictions were based on fuel-air cycle analyses, computer simulation, and engine test data. The results reveal that diesel driving cycle performance can be increased by 20% through increased turbocharging, turbocompounding, and Rankine engine compounding. The Rankine engine compounding provides about three times as much improvement as turbocompounding but also costs about three times as much. Performance for either is approximately doubled if applied to an adiabatic diesel.

Leising, C. J.↗

NASA NTRS1978

The impact of municipal refuse utilization on energy and our environment

The incinerator/boiler configuration is stressed as the most reliable method of waste utilization. It is also pointed out that the high cost of refuse disposal and the ever increasing cost of energy, have made this method attractive. A plan is outlined for operating a waste utilization plant. Community participation is encouraged in investigating the feasibility of refuse to energy facilities in their area.

Source record↗

NASA NTRS1978

Solar heating and cooling system for an office building at Reedy Creek Utilities

The solar energy system installed in a two story office building at a utilities company, which provides utility service to Walt Disney World, is described. The solar energy system application is 100 percent heating, 80 percent cooling, and 100 percent hot water. The storage medium is water with a capacity of 10,000 gallons hot and 10,000 gallons chilled water. Performance to date has equaled or exceeded design criteria.

Source record↗

NASA NTRS1976

Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

Brown, Dale H.↗

NASA NTRS1979

Wind turbines for electric utilities: Development status and economics

The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a fuel saver is discussed and the COE range that would be generally attractive to utilities is indicated.

Ramler, J. R.↗

NASA NTRS1979

Wind turbines for electric utilities - Development status and economics

The technology and economics of the large, horizontal-axis wind turbines currently in the Federal Wind Energy Program are presented. Wind turbine technology advancements made in the last several years are discussed. It is shown that, based on current projections of the costs of these machines when produced in quantity, they should be attractive for utility application. The cost of electricity (COE) produced at the busbar is shown to be a strong function of the mean wind speed at the installation site. The breakeven COE as a 'fuel saver' is discussed and the COE range that would be generally attractive to utilities is indicated.

Ramler, J. R.↗

NASA NTRS1979

Lewis Research Center studies of multiple large wind turbine generators on a utility network

A NASA-Lewis program to study the anticipated performance of a wind turbine generator farm on an electric utility network is surveyed. The paper describes the approach of the Lewis Wind Energy Project Office to developing analysis capabilities in the area of wind turbine generator-utility network computer simulations. Attention is given to areas such as, the Lewis Purdue hybrid simulation, an independent stability study, DOE multiunit plant study, and the WEST simulator. Also covered are the Lewis mod-2 simulation including analog simulation of a two wind turbine system and comparison with Boeing simulation results, and gust response of a two machine model. Finally future work to be done is noted and it is concluded that the study shows little interaction between the generators and between the generators and the bus.

Gilbert, L. J.↗

NASA NTRS1979

On attaining lower sidelobes and new antenna envelopes for better orbit spectrum utilization in satellite broadcasting

The concept of using beam-shaping techniques to reduce sidelobe levels at the expense of efficiency is introduced and analyzed with respect to the potential for improving orbit-spectrum utilization. Emphasis is placed on a simple method: improving the antenna patterns used in satellite systems, for both the satellite antennas and the ground station antennas. Only broadcasting applications are considered. The discussion includes how the antenna envelope can be improved, how this improvement can be interpreted in terms of orbit spectrum utilization efficiency, and whether this improved envelope is actually realizable and feasible. It is noted that the magnitude of the improvement with a better spacecraft antenna increases rapidly as the coverage area decreases.

Janky, J. M.↗

NASA NTRS1980

Upper stages utilizing electric propulsion

The payload characteristics of geocentric missions which utilize electron bombardment ion thruster systems are discussed. A baseline LEO to GEO orbit transfer mission was selected to describe the payload capabilities. The impacts on payloads of both mission parameters and electric propulsion technology options were evaluated. The characteristics of the electric propulsion thrust system and the power requirements were specified in order to predict payload mass. This was completed by utilizing a previously developed methodology which provides a detailed thrust system description after the final mass on orbit, the thrusting time, and the specific impulse are specified. The impact on payloads of total mass in LEO, thrusting time, propellant type, specific impulse, and power source characteristics was evaluated.

Byers, D. C.↗