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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 1,063 records · Page 59

All sources NASA NTRS DOE OSTI

NASA NTRS1973

Compilation, design tests: Energetic particles Satellite S-3 including design tests for S-3A, S-3B and S-3C

A compilation of engineering design tests which were conducted in support of the Energetic Particle Satellite S-3, S-3A, and S-3b programs. The purpose for conducting the tests was to determine the adequacy and reliability of the Energetic Particles Series of satellites designs. The various tests consisted of: (1) moments of inertia, (2) functional reliability, (3) component and structural integrity, (4) initiators and explosives tests, and (5) acceptance tests.

Ledoux, F. N.↗

NASA NTRS1973

Measurement of the vibration of structures with a three-component vibration sensor

The effects of transverse waves and longitudinal displacements on transverse displacements in a plate are studied using a three component vibration sensor. Limitations of using the sensor in such measurements are: (1) sensor connection to the plate leads to changes in transverse displacement points on the plate surface, (2) the sensor has a finite magnitude of selectivity with respect to vibrations in the direction of the different channel axes, (3) longitudinal displacements of plate surface create restrictions on relative sensitivity of sensor to longitudinal-transverse waves, and (4) tranverse displacement of plate surface during longitudinal wave propagation also creates a restriction on sensor sensitivity to transverse waves.

Yeskov, V. V.↗

NASA NTRS1976

The internal plasma state of the high speed solar wind at 1 AU

The character of particle velocity distributions in the high speed solar wind is described. It is found that electron distribution shapes differ from simple bi-Maxwellians in that a hot strongly beamed high energy electron component is always present, and is observed to move relative to a distinct low energy electron component along the magnetic field direction away from the sun. The velocity difference between hot and cold electron components appears, at times, to be strongly correlated with the local Alfven speed. Proton velocity distributions are also best represented by two relatively convecting unresolved components. Evidence is presented which supports the idea that the two-component proton structure observed in high speed regions is intimately related to fine scale velocity variations at 1 AU, and probably to prominent spatial and/or temporal structures present throughout that part of the corona from which the solar wind evolves.

Feldman, W. C.↗

NASA NTRS1979

Development of SiAlON materials

Cold pressing and sintering techniques were used to produce ceramic test specimens in which the major phase was either Si3N4 or a solid solution having the beta Si3N4 structure. Additional components were incorporated to promote liquid phase sintering. Glass and/or crystalline phase were consequently retained in boundaries between Si3N4 grains which largely determined the physical properties of the bodies. Systems investigated most extensively included R-Si-Al-O-N (R = rare earth element) Zr-Si-Al-O-N, Y-Si-Be-O-N, and R1-R2-Si-O-N. Room temperature and 1370 C modulus of ruptured, 1370 C creep, and oxidation behavior are discussed in terms of phase relationships in a parent quinery, and relavent oxide systems.

Layden, G. K.↗

NASA NTRS1979

Non-flammable polyimide materials for aircraft and spacecraft applications

Recent developments in polyimide chemistry show promise for producing materials with very low flammability and a wide range of mechanical properties. Polyimide foams can be synthesized to provide fire safety without detectable formation of smoke or toxic byproducts below 204 C (400 F), thus avoiding an environment which is lethal to human habitation. This work has been and is currently being performed under development programs, the objective of which is to provide cost effective processes for producing thermally stable, polyimide flexible resilient foams, thermal-acoustical insulating materials, rigid low density foam panels, and high strength foam structures. The chemical and physical properties demonstrated by these materials represent a technological advancement in the art of thermally stable polyimide polymers which are expected to insure fire protection of structures and components used in air transportation and space exploration. Data compiled to date on thermal, physical and functional properties of these materials are presented.

Gagliani, J.↗

NASA NTRS1982

Cam-Design Torque Wrench

New Torque wrench for electrical connnectors automatically tightens its grip with increasing torque to insure against slippage. Tool requires only minimal clearance between connector and adjacent structures or components. Wrench is operated with one hand and can be used on connectors of various shapes.

Schick, P. H. J.↗

NASA NTRS1980

Erosion of composite materials

A model for describing the response of uncoated and coated fiber reinforced composites subjected to repeated impingements of liquid (rain) droplets is presented. The model is based on the concept that fatigue is the dominant factor in the erosion process. Algebraic expressions are provided which give the incubation period, the rate of mass loss past the incubation period, and the total mass loss of the material during rain impact. The influence of material properties on erosion damage and the protection offered by different coatings are discussed and the use of the model in the design in the design of structures and components is illustrated.

Springer, G. S.↗

NASA NTRS1980

B2 1141 + 37 - A giant radio galaxy with remarkable radio and optical properties

Observations of the giant radio galaxy B2 1141+37, which has a widely separated two-component radio structure and is optically identified with a tight chain of galaxies, are reported. The source was observed at 4900 MHz with the VLA at an effective integration time of 17 min. The map obtained shows two radio lobes with maxima coinciding with those in a previous 1415 MHz map and intensities about 1.5 times smaller than those obtained by extrapolating the spectrum defined by the flux density at 408 and 1415 MHz. Measurements of the redshifts of the two brightest galaxies identified with the radio source with an image intensified dissector scanner result in values of 0.1145 and 0.1155, which imply, with a Hubble constant of 50 km/sec per Mpc, a distance of 687 Mpc to the radio source and a separation of 1.0 Mpc between the lobes making it one of the largest radio sources known.

Ulrich, M. H.↗

NASA NTRS1980

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

Progress in the development of a gas turbine engine to improve fuel economy, reduce gaseous emissions and particulate levels, and compatible with a variety of alternate fuels is reported. The powertrain is designated AGT101 and consists of a regenerated single shaft gas turbine engine, a split differential gearbox and a Ford Automatic Overdrive production transmission. The powertrain is controlled by an electronic digital microprocessor and associated actuators, instrumentation, and sensors. Standard automotive accessories are driven by engine power provided by an accessory pad on the gearbox. Component/subsystem development progress is reported in the following areas: compressor, turbine, combustion system, regenerator, gearbox/transmission, structures, ceramic components, foil gas bearing, bearings and seals, rotor dynamics, and controls and accessories.

Source record↗

NASA NTRS1982

The 1981 NASA/ASEE Summer Faculty Fellowship Program: Research reports

Research reports related to spacecraft industry technological advances, requirements, and applications were considered. Some of the topic areas addressed were: (1) Fabrication, evaluation, and use of high performance composites and ceramics, (2) antenna designs, (3) electronics and microcomputer applications and mathematical modeling and programming techniques, (4) design, fabrication, and failure detection methods for structural materials, components, and total systems, and (5) chemical studies of bindary organic mixtures and polymer synthesis. Space environment parameters were also discussed.

Karr, G. R.↗

NASA NTRS1982

Fatigue and fracture research in composite materials

The fatigue, fracture, and impact behavior of composite materials are investigated. Bolted and bonded joints are included. The solutions developed are generic in scope and are useful for a wide variety of structural applications. The analytical tools developed are used to demonstrate the damage tolerance, impact resistance, and useful fatigue life of structural composite components. Standard tests for screening improvements in materials and constituents are developed.

T. Kevin O'Brien↗

NASA NTRS1984

Rotordynamic Characteristics of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine)

Rotational stability of turbopump components in the space shuttle main engine was studied via analysis of component and structural dynamic models. Subsynchronous vibration caused unacceptable migration of the rotor/housing unit with unequal load sharing of the synchronous bearings that resulted in the failure of the High Pressure Oxygen Turbopump. Linear analysis shows that a shrouded inducer eliminates the second critical speed and the stability problem, a stiffened rotor improves the rotordynamic characteristics of the turbopump, and installing damper boost/impeller seals reduces bearing loads. Nonlinear analysis shows that by increasing the "dead band' clearances, a marked reduction in peak bearing loads occurs.

Childs, D. W.↗

NASA NTRS1984

A user friendly operating system for the GLAS 4th order forecast-analysis system

The GLAS 4th Order Forecast-Analysis System is described in terms of its operating system requirements. A description of the operating system structure and components is given.

Pfaendtner, J.↗

NASA NTRS1984

Diamondlike flake composites

A carbon coating is vacuum arc deposited on a smooth surface of a target which is simultaneously ion beam sputtered. The bombarding ions have sufficient energy to create diamond bonds. Spalling occurs as the carbon deposit thickens. The resulting diamond-like carbon flakes are mixed with a binder or matrix material to form a composite material having improved thermal, electrical, mechanical, and tribological properties when used in aerospace structures and components.

Banks, B. A.↗

NASA NTRS1984

ICAN: Integrated composites analyzer

The ICAN computer program performs all the essential aspects of mechanics/analysis/design of multilayered fiber composites. Modular, open-ended and user friendly, the program can handle a variety of composite systems having one type of fiber and one matrix as constituents as well as intraply and interply hybrid composite systems. It can also simulate isotropic layers by considering a primary composite system with negligible fiber volume content. This feature is specifically useful in modeling thin interply matrix layers. Hygrothermal conditions and various combinations of in-plane and bending loads can also be considered. Usage of this code is illustrated with a sample input and the generated output. Some key features of output are stress concentration factors around a circular hole, locations of probable delamination, a summary of the laminate failure stress analysis, free edge stresses, microstresses and ply stress/strain influence coefficients. These features make ICAN a powerful, cost-effective tool to analyze/design fiber composite structures and components.

Murthy, P. L. N.↗

NASA NTRS1985

Diamondlike flakes

A carbon coating was vacuum arc deposited on a smooth surface of a target which was simultaneously ion beam sputtered. The bombarding ions have sufficient energy to create diamond bonds. Spalling occurs as the carbon deposit thickens. The resulting diamond like carbon flakes improve thermal, electrical, mechanical, and tribological properties when used in aerospace structures and components.

Banks, B. A.↗

NASA NTRS1984

Alternate nozzle ablative materials program

Four subscale solid rocket motor tests were conducted successfully to evaluate alternate nozzle liner, insulation, and exit cone structural overwrap components for possible application to the Space Shuttle Solid Rocket Motor (SRM) nozzle asasembly. The 10,000 lb propellant motor tests were simulated, as close as practical, the configuration and operational environment of the full scale SRM. Fifteen PAN based and three pitch based materials had no filler in the phenolic resin, four PAN based materials had carbon microballoons in the resin, and the rest of the materials had carbon powder in the resin. Three nozzle insulation materials were evaluated; an aluminum oxide silicon oxide ceramic fiber mat phenolic material with no resin filler and two E-glass fiber mat phenolic materials with no resin filler. It was concluded by MTI/WD (the fabricator and evaluator of the test nozzles) and NASA-MSFC that it was possible to design an alternate material full scale SRM nozzle assembly, which could provide an estimated 360 lb increased payload capability for Space Shuttle launches over that obtainable with the current qualified SRM design.

Kimmel, N. A.↗

NASA NTRS1984

ICAN - Integrated composites analyzer

Murthy, P. L. N.↗