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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Apparatus for Sizing and Rewinding Graphite Fibers

Equipment ideally suited for research and development of new sizing solutions. Designed expecially for applying thermoplastic sizing solutions to graphite tow consisting of 3,000 to 12,000 filaments per tow, but accommodates other solutions, filament counts, and materials other than graphite. Closed system containing highly volatile methylene chloride vapors. Also ventilation system directly over resin reservoir. Concept used to apply sizing compounds on fiber tows or yarn-type reinforcement materials used in composite technology. Sizing solutions consist of compounds compatible with thermosets as well as thermoplastics.

Wilson, M. L.↗
NASA NTRS1995

Review of North Atlantic Source Waters

North Atlantic Deep Water (NADW) ventilates the deep World Ocean. It not only carries relatively well-oxygenated waters, but also other substances derived from recent sea-surface exchanges. There are five regional sources for NADW: (1) derivatives of the salty Mediterranean Sea outflow, (2) products of open-ocean convection in the Labrador Sea, (3) Iceland-Scotland Overflow Water from the Norwegian Sea - salty by virtue of mixing with saline water near the sills, (4) Denmark Strait Overflow Water from the Iceland and Greenland Seas - which retains a high-density, relatively low-salinity signal, and (5) remnants of deep water from the Antarctic circumpolar region - freshest of the bottom waters. Despite the differences of characteristics of the source waters, the NADW is relatively uniform. Because the formation of each of the five source waters may be viewed as a response to a complex series of events, it is difficult to examine the sensitivity of NADW to environmental fluctuations. It is known that the deep northern North Atlantic is relatively closely coupled to the sea surface in the Greenland and Iceland seas. The most recent studies indicate a minimum response time of only two years between the introduction of a passive signal north of Iceland and its appearance in the deep northwest Atlantic.

James H Swift↗
NASA NTRS1984

Steps toward 8m honeycomb mirrors IV - Some aspects of design and fabrication

The tolerances in glass homogeneity, thermal control, and support of the blank, necessary to meet the requirements of telescopes in the best ground-based sites, are defined for a hypothetical 8-m honeycomb mirror spin-casting facility. Homogeneity in expansion coefficient of 10 to the -8th/C and thermal equilibration to 0.1 C are estimated. Laboratory measurements show that both can be met by a ventilated honeycomb of borosilicate or similar glass. Adequate resistance to wind pressure and buffeting can be achieved by an axial support that responds to pressure on the three defining points. Annealing of the blank at the peak cooling rate of 20 C/day will take about six weeks, leading to a temporary stress of 15 kg/sq cm.

Angel, J. R. P.↗
NASA NTRS1985

Response time correlations for platinum resistance thermometers

The 'plunge method' recommended by ASTM has been used to determine the time constant of 100-ohm platinum resistance thermometers (PRT) considered for use in the National Transonic Facility. It is shown that the response time of ventilated PRT can be correlated with the reciprocal of the heat transfer coefficient in a given field. Universal correlations are established for the 100- and 1000-ohm PRT with uncertainties of 20 and 30 percent, respectively. The correlations are found to be consistent with the uncertainty involved in heat transfer correlations available in the literature and are recommended for use in flowing liquids and gases.

Pandey, D. K.↗
NASA NTRS1986

HVAC modifications and computerized energy analysis for the Operations Support Building at the Mars Deep Space Station at Goldstone

The key heating, ventilation, and air-conditioning (HVAC) modifications implemented at the Mars Deep Space Station's Operation Support Building at Jet Propulsion Laboratories (JPL) in order to reduce energy consumption and decrease operating costs are described. An energy analysis comparison between the computer simulated model for the building and the actual meter data was presented. The measurement performance data showed that the cumulative energy savings was about 21% for the period 1979 to 1981. The deviation from simulated data to measurement performance data was only about 3%.

Halperin, A.↗
NASA NTRS1986

Analysis of interacting dual lifting ejector systems

An analytical treatment is presented for a flowfield generated by a pair of interacting, two-dimensional parallel jets, representative of the two exhaust streams issuing from the thrust augmentor nozzles of dual lifting jet VTOL aircraft propulsion systems. Predictions of the analysis for the ratio of primary to secondary velocity are in close agreement with experimentally observed values, if the spreading rate parameter is allowed to assume a value greater than that which applies to a free jet. Theoretical results are combined with existing experimental data for unventilated jets, in order to arrive at an estimate of the thrust augmentation produced by a jet pair with an arbitrary degree of ventilation.

Lund, T. S.↗
NASA NTRS1986

Applications of adaptive-wall wind tunnels

A novel processing technique for the flowfield data generated by an adaptive wall wind tunnel is presented whose basic premise is the possible undesirability of forcing such a wind tunnel to simulate free-air conditions. The concept of a 'phantom' wind tunnel is introduced for both two- and three-dimensional wind tunnels, yielding a continuous spectrum of flow fields, ranging from the original passive and ventilated configuration to a fully adaptive one. In order to implement these procedures, active control is limited to floor and ceiling surfaces.

Davis, S. S.↗
NASA NTRS1986

Effect of simulated weightlessness on exercise-induced anaerobic threshold

The effect of simulated weightlessness, induced by ten days of continuous bedrest (BR) in the -6 deg head-down position, on the exercise-induced anaerobic threshold (AT) was determined by comparing specific ventilatory and gas-exchange measurements during an incremental ergometer test performed before and after BR. The primary index for determining the exercise-induced AT values of each subject was visual identification of the workrate or oxygen uptake (VO2) at which the ratio of the expired minute ventilation volume (VE) to VO2 exhibited a systematic increase without a concomitant increase in the VE/VCO2 value. Following BR, the mean VO2max of the subjects decreased by 7.0 percent, and the AT decreased from a mean of 1.26 L/min VO2 before BR to 0.95 L/min VO2 after BR. The decrease in AT was manifested by a decrease in both absolute and relative workrates. The change in AT correlated significantly with the change in plasma volume but not with the change in VO2max. The results suggest that the reduction in AT cannot be completely explained by the reduction in VO2, and that the AT decrease is associated with the reduction in intravascular fluid volume.

Convertino, V. A.↗
NASA NTRS1986

Space bio-technology in housing

Gas chromatography and mass spectrometry data obtained from monitoring atmospheric pollutants in Skylab spurred studies of indoor pollutants in terrestrial buildings. Subsequent studies of techniques for removing the pollutants from space habitats have led to building concepts which achieve the same purpose on earth. The Skylab data indicated that the synthesized organic materials used in many modern buildings, furnishings, personal clothing and aerosols add significant amounts of chemicals to the indoor atmosphere. Lowered circulation and ventilation rates to conserve energy have caused trapping of these substances in buildings. Studies of methods for space modules which will use plants and microbes to absorb airborne and wastewater pollutants have defined biotechnology designs which can be applied to remove pollutants from air and wastewater organically. Plant roots trap pollutants from wastewater and leaves readily absorb air pollutants, as well as improve the overall energy efficiency of buildings. Several designs which incorporate biotechnology to enhance both the aesthetics and efficiency of homes and office buildings are illustrated.

Wolverton, B. C.↗
NASA NTRS1987

Molded Concrete Center Mine Wall

Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.

Lewis, E. V.↗
NASA NTRS1987

Algorithm for Fluid Networks

Algorithm performs either transient integration or steady-state relaxation of network that represents internal fluid system. Valid for both single and two-phase flow of any fluid and includes both heat-transfer and work terms. General enough to simulate almost any flow system to almost any degree of detail desired. Encoded into computer program FLUINT, will work in conjunction with SINDA-85 program to enable analysis of pipelines; heating, ventilating, and cooling systems; and almost any other system that involves both fluid flow and heat transfer. Other possible extensions includes effects of flexibilities of containers, high-velocity flow, gravitation, acceleration, and opening and closing valves.

Cullimore, Brent A.↗
NASA NTRS1986

Construction of a 2- by 2-foot transonic adaptive-wall test section at the NASA Ames Research Center

The development of a new production-size, two-dimensional, adaptive-wall test section with ventilated walls at the NASA Ames Research Center is described. The new facility incorporates rapid closed-loop operation, computer/sensor integration, and on-line interference assessment and wall corrections. Air flow through the test section is controlled by a series of plenum compartments and three-way slide vales. A fast-scan laser velocimeter was built to measure velocity boundary conditions for the interference assessment scheme. A 15.2-cm- (6.0-in.-) chord NACA 0012 airfoil model will be used in the first experiments during calibration of the facility.

Morgan, Daniel G.↗
NASA NTRS1987

Evaluation of influence coefficient matrices for an adaptive-wall wind tunnel and applications to one-step convergence scheme

Within the framework of ventilated adaptive-wall wind tunnel testing, experiments were conducted to evaluate the influence coefficients from the side-wall pressure distribution, the streamwise velocity distribution, and the vertical velocity distribution on two control surfaces. Consideration is given to the effects of Mach number, superposition, suction, blowing, and the presence of a nonlifting model. It is shown that a single-step convergence scheme reduces the testing time by eliminating the intermediate experimental iterations; however, its success depends on the accuracy of the influence coefficients.

Celik, Z. Z.↗
NASA NTRS1988

Portable Airflow Meter

Compact hand-held instrument measures airflow. Consists of hot-wire anemometer probe in flow-straightening tube that reduces swirling. Configuration developed empirically to reduce length of instrument to practical dimension for use and storage in confined space. Two versions of new straightener only 17 and 18 in. long. Weighs less than 8 lb. and readily stored on Space Shuttle, developed to measure airflow in waster-collection system during flight. Used on Earth to measure airflow in ventilation systems, vacuum cleaners, and the like.

Burgett, Frank A.↗
NASA NTRS1987

Plant Growth Module (PGM) conceptual design

The Plant Growth Module for the Controlled Ecological Life Support System (CELSS), designed to answer basic science questions related to growing plants in closed systems, is described functionally with artist's conception drawings. Subsystems are also described, including enclosure and access; data acquisition and control; gas monitor and control; heating, ventilation, and air conditioning; air delivery; nutrient monitor and control; microbial monitoring and control; plant support and nutrient delivery; illumination; and internal operations. The hardware development plan is outlined.

Schwartzkopf, Steven H.↗
NASA NTRS1987

The respiratory system under weightlessness

Studies of pulmonary functions at rest to be studied on Spacelab mission D-2 are introduced. Gravity dependence of the distribution of ventilation (single breath washout, multibreath washout-washin); chest wall shape and motion; and the vascular compartment (lung blood flow, capillary volume, liquid content, diffusive capacity) are discussed.

Paiva, M.↗
NASA NTRS1987

Design and performance of the KSC Biomass Production Chamber

NASA's Controlled Ecological Life Support System program has instituted the Kennedy Space Center 'breadboard' project of which the Biomass Production Chamber (BPC) presently discussed is a part. The BPC is based on a modified hypobaric test vessel; its design parameters and operational parameters have been chosen in order to meet a wide range of plant-growing objectives aboard future spacecraft on long-duration missions. A control and data acquisition subsystem is used to maintain a common link between the heating, ventilation, and air conditioning system, the illumination system, the gas-circulation system, and the nutrient delivery and monitoring subsystems.

Prince, Ralph P.↗
NASA NTRS1988

Gravitational independence of single-breath washout tests in recumbent dogs

The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

Tomioka, Shinichi↗