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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 181 records · Page 10

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NASA NTRS1980

Cost analysis of composite fan blade manufacturing processes

The relative manufacturing costs were estimated for large high technology fan blades prepared by advanced composite fabrication methods using seven candidate materials/process systems. These systems were identified as laminated resin matrix composite, filament wound resin matrix composite, superhybrid solid laminate, superhybrid spar/shell, metal matrix composite, metal matrix composite with a spar and shell, and hollow titanium. The costs were calculated utilizing analytical process models and all cost data are presented as normalized relative values where 100 was the cost of a conventionally forged solid titanium fan blade whose geometry corresponded to a size typical of 42 blades per disc. Four costs were calculated for each of the seven candidate systems to relate the variation of cost on blade size. Geometries typical of blade designs at 24, 30, 36 and 42 blades per disc were used. The impact of individual process yield factors on costs was also assessed as well as effects of process parameters, raw materials, labor rates and consumable items.

Stelson, T. S.↗

NASA NTRS1979

Food technology in space habitats

The research required to develop a system that will provide for acceptable, nutritious, and safe diets for man during extended space missions is discussed. The development of a food technology system for space habitats capable of converting raw materials produced in the space habitats into acceptable food is examined.

Karel, M.↗

NASA NTRS1979

Economic considerations in space industrialization

The industrial categories of the United States economy are surveyed to identify those which can function using dominantly lunar raw materials or lunar derived feedstocks (LDF) and solar energy. Sixty-four standard industrial categories (SIC) appear to be compatible with LDF inputs; another 166 SIC's might be adaptable to LDF and space industry if substitution of materials and/or terrestrial supplements were introduced. Analytic tools are presented to use in deciding optimal strategies by which a generalized economy can be developed in space in an optimal manner within given constraints of capital, products derived at a given time, local production costs, cost of import from earth and other factors.

Ayres, R. U.↗

NASA NTRS1979

Progress on the Dow Corning process for solar-grade silicon

The Dow Corning approach to increasing the resistivity of solar-grade silicon from about 0.04 ohm-cm (40 ppma B) to greater than 0.1 ohm-cm (10 ppma B) involves the use of high-purity raw materials carbothermically reduced in a specially designed electric arc furnace. Final purification occurs during Czochralski crystal growth of a polycrystalline ingot. This small-scale purification technology has resulted in silicon that has been fabricated into solar cells with a maximum AM1 conversion efficiency of 13.4%.

Hunt, L. P.↗

NASA NTRS1980

Method for horizontally growing ribbon crystal

A high speed method for forming ribbon crystal of desired width and thickness is characterized by drawing out the ribbon through a space whose distance is 5.7 times that of the thickness of the grown ribbon. The ribbon is drawn out between the molten body of the lower surface and the tip of the upper surface of the seed crystal and growing crystal. The ribbon growing at the tip of the seed crystal is drawn out horizontally and centrifugally by controlling the amount of cooling and heating. The temperature is maintained about equal to the upper surface of the outlets from which the molten substance is drawn, at least in certain portions of the crucible rim, the rim is elevated to prevent dropping of the molten raw material.

Kudo, B.↗

NASA NTRS1980

Health and safety: Preliminary comparative assessment of the Satellite Power System (SPS) and other energy alternatives

Data readily available from the literature were used to make an initial comparison of the health and safety risks of a fission power system with fuel reprocessing; a combined-cycle coal power system with a low-Btu gasifier and open-cycle gas turbine; a central-station, terrestrial, solar photovoltaic power system; the satellite power system; and a first-generation fusion system. The assessment approach consists of the identification of health and safety issues in each phase of the energy cycle from raw material extraction through electrical generation, waste disposal, and system deactivation; quantitative or qualitative evaluation of impact severity; and the rating of each issue with regard to known or potential impact level and level of uncertainty.

Habegger, L. J.↗

NASA NTRS1981

Evaluation of engineered foods for Closed Ecological Life Support System (CELSS)

A system of conversion of locally regenerated raw materials and of resupplied freeze-dried foods and ingredients into acceptable, safe and nutritious engineered foods is proposed. The first phase of the proposed research has the following objectives: (1) evaluation of feasibility of developing acceptable and reliable engineered foods from a limited selection of plants, supplemented by microbially produced nutrients and a minimum of dehydrated nutrient sources (especially those of animal origin); (2) evaluation of research tasks and specifications of research projects to adapt present technology and food science to expected space conditions (in particular, problems arising from unusual gravity conditions, problems of limited size and the isolation of the food production system, and the opportunities of space conditions are considered); (3) development of scenarios of agricultural production of plant and microbial systems, including the specifications of processing wastes to be recycled.

Karel, M.↗

NASA NTRS1980

Advanced resin systems for graphite epoxy composites

The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

Gilwee, W. J.↗

NASA NTRS1980

Chemicals from biomass - The U.S. prospects for the turn of the century

Historically, chemicals from biomass have been and are expected to be economical in three major areas: byproducts, specialty items and polymers. Assessments of producing major chemicals from biomass in a processing plant based on the available conversion techniques indicate that they are not economically attractive, with the possible exception of conversion to ammonia and ethanol. The deterrents are the heavy capital investments, dependability of raw material supply and transportation costs for large plants, lack of operation experience, inadaptability of market variations, and competition from petroleum and coal. More importantly, it is also shown that even if chemicals from biomass were economical today, the resultant savings in petroleum would be far less than those achieved through other options available for the utilization of biomass as fuel and structural material. Thus, it is concluded that near-term research and development must be toward improved conversion processes, recovery of valuable products from waste streams at existing plants, more efficient use of biomass of energy and more efficient production of superior material products.

Sarbolouki, M. N.↗

NASA NTRS1982

Bipulsating Technique for Silicon Production

Method controls reaction temperature and rate of reaction of sodium and silicon tetrafluoride by alternately adding measured amounts of reactants. Technique used in large reactor, where heat dissipation becomes serious problem, to control reactor temperatures. Highly efficient method, which would utilize almost 100 percent of raw materials.

Sanjurjo, A.↗

NASA NTRS1983

Electroforming for High-Performance Products

Report describes development of processes and procedures for preparation of specifications for electroforming nickel and copper outer shells on cooled rocket thrust-chamber liners. Specifications represent merging of technical contributions from many sources into guide for producers of electroformed, high-performance products. Raw materials, conducting solutions and deposition rates are evaluated.

Malone, G. A.↗

NASA NTRS1981

Insects: A nutritional alternative

Insects are considered as potential food sources in space. Types of insects consumed are discussed. Hazards of insect ingestion are considered. Insect reproduction, requirements, and raw materials conversion are discussed. Nutrition properties and composition of insects are considered. Preparation of insects as human food is discussed.

Dufour, P. A.↗

NASA NTRS1981

An hierarchical system architecture for automated design, fabrication, and repair

The architecture of an automated system which has the following properties is described: (1) if it is presented with a final product specification (within its capabilities) it will do the detailed design (all the way down to the raw materials if need be) and then produce that product; (2) if a faulty final product is presented to the system, it will repair it. Interesting extensions of this architecture would be the ability to add fabricator nodes when required and the ability to add entire ranks when required. This sort of system would be a useful component of a self-replicating system (used in space exploration).

Cliff, R. A.↗

NASA NTRS1983

Fabricating Slotted-Waveguide Arrays From Sheet Metal

Low-cost lightweight waveguides formed from rolls of aluminum. Array formed from sheared, punched, and bent aluminum sheets. Sheets alined with punched jig holes and joined by laser-beam or resistance spot welding. Process permits use of thin metal to reduce raw material costs and mass. Also holds closer tolerances than usually attained in sheet-metal work.

Brown, W. C.↗

NASA NTRS1982

Development of an all-metal thick film cost effective metallization system for solar cells

Electrodes made with pastes produced under the previous contract were analyzed and compared with raw materials. A needle-like structure observed on the electroded solar cell was identified as eutectic copper-silicon, a phase considered to benefit the electrical and metallurgical properties of the contact. Electrodes made from copper fluorocarbon and copper silver fluoride also contained this phase but had poor adhesion. A liquid medium, intended to provide transport during carbon fluoride decomposition was incorporated into the paste resulting in better adhesion. The product survived preliminary environmental tests. A 2 cm by 2 cm solar cell made with fluorocarbon activated copper electrodes and gave 7% AMI efficiency (without AR coating). Both silver fluoride and fluorocarbon screened paste electrodes can be produced for approximately $0.04 per watt.

Ross, B.↗

NASA NTRS1982

Plasma-sprayed self-lubricating coatings

One of the most important criterion for acceptable commercial application of a multiple phase composition is uniformity and reproducibility. This means that the performance characteristics of the coat - e.g., its lubricating properties, bond strength to the substrate, and thermal properties - can be readily predicted to give a desired performance. The improvement of uniformity and reproducibility of the coats, the oxidation behavior at three temperature ranges, the effect of bond coat and the effect of preheat treatment as measured by adhesive strength tests, coating examination procedures, and physical property measurements were studied. The following modifications improved the uniformity and reproducibility: (1) changes and closer control in the particle size range of the raw materials used, (2) increasing the binder content from 3.2% to 4.1% (dried weight), and (3) analytical processing procedures using step by step checking to assure consistency.

Nakamura, H. H.↗

NASA NTRS1981

Fuel quality-processing study. Volume 2: Literature survey

The validity of initial assumptions about raw materials choices and relevant upgrading processing options was confirmed. The literature survey also served to define the on-site (at the turbine location) options for fuel treatment and exhaust gas treatment. The literature survey also contains a substantial compilation of specification and physical property information about liquid fuel products relevant to industrial gas turbines.

Jones, G. E., Jr.↗

NASA NTRS1982

Single crystal growth of upgraded metallurgical silicon by HEM for photovoltaic applications

Commercially available metallurgical grade (MG) silicon has high B and P content which is not reduced significantly by directional solidification. By choosing high purity raw materials for an experimental Submerged Electrode Arc Furnace, most of the impurities are reduced to 10 ppmw. Directional solidification of upgraded metallurgical grade (UMG) silicon by the Heat Exchanger Method (HEM) has produced 16 cm x 16 cm cross section ingots with nearly single crystal structure. The main problem encountered during directional solidification was SiC impurities dispersed through the structure. Solar cells fabricated from UMG silicon that was directionally solidified twice by HEM have shown up to 12.33% (am1) conversion efficiency.

Khattak, C. P.↗