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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
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NASA NTRS1982

NASA participation in the 1980 PEPE/NEROS project: Data archive

Eight experimental air quality measurement systems were investigated during July and August 1980 as part of the EPA PEPE/NEROS fiel measurement program. Data from those efforts have been entered into an archive that may be accessed by other researchers. The data sets consists of airborne measurements of regional mixed layer heights and aerosol and ozone distributions as well as point measurements of meteorological parameters and ozone obtained during diurnal transitions in the planetary boundary layer. This report gives a discussion of each measurement system, a preliminary assessment of data quality, a description of the archive format for each data set, and a summary of several proposed scientific studies which will utilize these data.

Brewer, D. A.↗
NASA NTRS1980

Air quality model studies with application for southeastern Virginia

A single-cell photochemical air quality model incorporating (1) a published chemical mechanism, (2) advection, and (3) entrainment and emissions processes was constructed and compared with data from the EPA Regional Air Pollution Study. While agreement with measured CO and NO2 was established, O3 production was found to occur too rapidly and in excess. Calculated O3 levels improved when a 20% reduction in photolytic rate constants and a doubling of wind speed were applied. The results of the model sensitivity studies are being incorporated into the design and conduct of field measurement programs for the characterization of the vertical and horizontal homogeneity of an air quality region.

Brewer, D. A.↗
NASA NTRS1980

Calculation of multiple scattered radiation in clean atmospheres

Calculations of the multiple-scattered solar radiation in the earth's atmosphere are compared with telephotometer measurements of the sky intensity obtained during the EPA-sponsored Visibility Impairment by Sulfate Transport and Transformation in the Atmosphere experiment. The doubling and adding calculation technique, in which the reflection and transmission properties of the atmosphere are computed by initially calculating such properties for the case of very thin layers and then adding adjacent layers together, is described and compared with data for two cloudless sky conditions. The first is typical of clean tropospheric conditions, and the second represents an ultraclean atmosphere in which surface aerosol scattering is much lower than molecular scattering. Good agreement is found between the computations and the measurement data.

Bergstrom, R. W.↗
NASA NTRS1982

A study of persistent elevated pollution episodes in the northeastern United States

To examine chemical transformation within stagnant air masses and the atmospheric processes acting upon such air masses, the United States EPA sponsored a study in the summer of 1980 in the northeastern region of the country. Ten research aircraft and several mobile and stationary surface monitoring platforms participated in an intensive measurement program between 16 July and 15 August 1980. Pollutants of interest included SO2, NO, NO(x), HC, O3, sulfate, nitrate, and aerosols in general. This paper summarizes the activities of these research aircraft. Three aircraft and one helicopter logged a total of 353 flight hours during 100 missions in the program. The flight patterns and data collected for each mission are documented. This summary will allow scientists who are interested in this data base to identify subsets of the data for model development.

Vaughan, W. M.↗
NASA NTRS1982

Preliminary risk benefit assessment for nuclear waste disposal in space

This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.

Rice, E. E.↗
NASA NTRS1981

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

An automotive gas turbine powertrain system which, when installed in a 1985 production vehicle (3000 pounds inertia weight), is being developed with a CFDC fuel economy of 42.8 miles per gallon based on Environmental Protection Agency (EPA) test procedures and diesel No. 2 fuel. The AGT-powered vehicle shall give substantially the same overall vehicle driveability and performance as a comparable 1985 production vehicle powered by a conventional spark ignition powertrain system (baseline system). Gaseous emissions and particulate levels less than: NOx = 0.4 gm/mile, HC = 0.41 gm/mile, and CO = 3.4 gm/mile, and a total particulate of 0.2 gm/mile, using the same fuel as used for fuel economy measurements is expected, along with the ability to use a variety of alternate fuels.

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NASA NTRS1982

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

A gas turbine powertrain for automobiles with reduced fuel consumption and reduced environmental impact is investigated. The automotive gas turbine, when installed in an automobile (3000 pounds inertia weight), provides a CFDC fuel economy of 42.8 miles per gallon based on EPA test procedures and diesel No. 2 fuel. The AGT powered vehicle substantially gives the same overall vehicle driveability and performance as a comparable production vehicle powered by a conventional spark ignition powertrain system. The emissions are less than federal standards, and a variety of fuels can be used.

Source record↗
NASA NTRS1982

Catalyst durability evaluation for advanced gas turbine engines

Catalytic combustion has demonstrated the ability to provide low NO(x) emissions while maintaining high combustion efficiency. Recently, under joint NASA Lewis, EPA, and Acurex sponsorship, a catalytic reactor was tested for 1000 hours to demonstrate durability in combustion environments representative of advanced automotive gas turbine engines. At a 740K air preheat temperature and a propane fuel/air ratio of 0.028 by mass, the adiabatic flame temperature was held at about 1700K. The graded cell monolithic reactor measured 5 cm in diameter by 10.2 cm in length and was operated at a reference velocity of 13.4 m/s at 1 atmosphere pressure. Measured NO(x) levels remained below 5 ppm while unburned hydrocarbon concentrations registered near zero and carbon monoxide levels were nominally below 20 ppm. The durability test included several parametric turndown studies and ended with a series of on/off cycling tests to further characterize reactor performance.

Snow, G. C.↗
NASA NTRS1982

Optimization technique for improved microwave transmission from multi-solar power satellites

An optimization technique for generating antenna illumination tapers allows improved microwave transmission efficiencies from proposed solar power satellite (SPS) systems and minimizes sidelobe levels to meet preset environmental standards. The cumulative microwave power density levels from 50 optimized SPS systems are calculated at the centroids of each of the 3073 counties in the continental United States. These cumulative levels are compared with Environmental Protection Agency (EPA) measured levels of electromagnetic radiation in seven eastern cities. Effects of rectenna relocations upon the power levels/population exposure rates are also studied.

Arndt, G. D.↗
NASA NTRS1983

Lidar remote measurements of Space Shuttle ground cloud emissions

The application of lidar remote sensing techniques to the measurement of spacecraft-booster-exhaust-cloud parameters is illustrated, using data obtained from the launch of STS-3. Mie-scatter measurements of plume and cloud particulates were made by a mobile unit with computer controlled elevation and azimuth coverage. Scattergraphs of typical STS-3 lidar data are presented and discussed. The potential use of DIAL techniques to measure the concentrations of HCl, N2H4, and NO2 is evaluated in terms of EPA overall-standard-deviation guidelines. It is shown that currently operational lidar systems can be modified to determine contamination or air pollution by these molecular species resulting from spacecraft launches.

Caputo, B.↗
NASA NTRS1983

Assessment of institutional barriers to the use of natural gas fuel in automotive vehicle fleets

Institutional barriers to the use of natural gas as a fuel for motor vehicle fleets were identified. Recommendations for barrier removal were developed. Eight types of institutional barriers were assessed: (1) lack of a national standard for the safe design and certification of natural gas vehicles and refueling stations; (2) excessively conservative or misapplied state and local regulations, including bridge and tunnel restrictions, restrictions on types of vehicles that may be fueled by natural gas, zoning regulations that prohibit operation of refueling stations, parking restrictions, application of LPG standards to LNG vehicles, and unintentionally unsafe vehicle or refueling station requirements; (3) need for clarification of EPA's tampering enforcement policy; (4) the U.S. hydrocarbon standard; (5) uncertainty concerning state utility commission jurisdiction; (6) sale for resale prohibitions imposed by natural gas utility companies or state utility commissions; (7) uncertainty of the effects of conversions to natural gas on vehicle manufactures warranties; and (8) need for a natural gas to gasoline equivalent units conversion factor for use in calculation of state road use taxes.

Jablonski, J.↗
NASA NTRS1984

Advanced onboard storage concepts for natural gas-fueled automotive vehicles

The evaluation of several advanced concepts for storing natural gas at reduced pressure is presented. The advanced concepts include adsorption on high surface area carbon, adsorption in high porosity zeolite, storage in clathration compounds, and storage by dissolution in liquid solvents. High surface area carbons with high packing density are the best low pressure storage mediums. A simple mathematical model is used to compare adsorption storage on a state of the art carbon with compression storage. The model indicates that a vehicle using adsorption storage of natural gas at 3.6 MPa will have 36 percent of the range, on the EPA city cycle, of a vehicle operating on a compression storage system having the same physical size and a peak storage pressure of 21 MPa. Preliminary experiments and current literature suggest that the storage capacity of state of the art carbons could be improved by as much as 50 percent, and that adsorption systems having a capacity equal to compression storage at 14 MPa are possible without exceeding a maximum pressure of 3.6 MPa.

Remick, R. J.↗
NASA NTRS1982

Energy efficient engine component development and integration program

The development of the technology to improve energy efficiency of propulsion systems for subsonic commercial aircrafts was examined. Goals established include: (1) fuel consumption, reduction in flight propulsion system; (2) direct operation cost; (3) noise, with provision for engine growth corresponding to future engine application; and (4) emissions, EPA new engine standards.

Source record↗
NASA NTRS1984

Corrosion properties of second-generation conductive materials

Since the introduction of silver-filled epoxy adhesives and silver-filled nitrocellulose lacquer as RFI control materials, a number of new materials have been introduced. The resin carriers have been changed in an effort to make the materials more usable or more EPA acceptable and the fillers have been varied in an effort to make the materials less costly. The corrosion-related properties of second-generation materials were assessed, including adhesives, caulks, and greases. Aluminum 2024 was used as the only substrate material. Ten days of salt fog was used as the corrosive environment. If a noble material such as silver, nickel, or carbon is sandwiched with aluminum an increase in dc resistance results given enough time. If this is unsatisfactory electrically it should either not be used or have all corrosive environments excluded.

Groshart, E.↗
NASA NTRS1984

Automotive Stirling engine systems development

The objective of the Automotive Stirling Engine (ASE) program is to develop a Stirling engine for automotive use that provides a 30 percent improvement in fuel economy relative to a comparable internal-combustion engine while meeting emissions goals. This paper traces the engine systems' development efforts focusing on: (1) a summary of engine system performance for all Mod I engines; (2) the development, program conducted for the upgraded Mod I; and (3) vehicle systems work conducted to enhance vehicle fuel economy. Problems encountered during the upgraded Mod I test program are discussed. The importance of the EPA driving cycle cold-start penalty and the measures taken to minimize that penalty with the Mod II are also addressed.

Richey, A. E.↗
NASA NTRS1985

Airborne Lidar measurements of aerosols, mixed layer heights, and ozone during the 1980 PEPE/NEROS summer field experiment

A detailed summary of the NASA Ultraviolet Differential Absorption Lidar (UV DIAL) data archive obtained during the EPA Persistent Elevated Pollution Episode/Northeast Regional Oxidant Study (PEPE/NEROS) Summer Field Experiment Program (July through August 1980) is presented. The UV dial data set consists of remote measurements of mixed layer heights, aerosol backscatter cross sections, and sequential ozone profiles taken during 14 long-range flights onboard the NASA Wallops Flight Center Electra aircraft. These data are presented in graphic and tabular form, and they have been submitted to the PEPE/NEROS data archive on digital magnetic tape. The derivation of mixing heights and ozone profiles from UV Dial signals is discussed, and detailed intercomparisons with measurements obtained by in situ sensors are presented.

Browell, E. V.↗
NASA NTRS1986

In-situ observations of cometary pick-up ions greater than 0.2 AU upstream of Comet Halley - ICE observations

Burst-like enhancements of energetic ions were observed by the EPAS instrument on the International Cometary Explorer (ICE) during its closest approach to (28 x 10 to the 6th km upstream of) Comet P/Halley, in late March 1986. The ion intensity was modulated by the varying solar wind speed (the latter reaching maxima of around 600 km/s), as was found to be the case for heavy cometary ions accelerated by pick-up in the solar wind flow, during the ICE encounter with Comet P/Giacobini-Zinner (G-Z). Therefore it is concluded that the observed pick-up ions (most probably greater than or equal to 65 keV oxygen ions) are produced by heavy neutrals from Comet Halley. The observations of energetic ions at such large distances suggest the presence, in the neutral atmosphere surrounding the nucleus, of a component with an ionization scale length of 5-10 million km, resulting from a relatively high expansion speed of a few km/s and/or an ionization time scale of a few times 10 to the 6ths.

Wenzel, K.-P.↗