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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Ferrite logic reliability study

Development and use of digital circuits called all-magnetic logic are reported. In these circuits the magnetic elements and their windings comprise the active circuit devices in the logic portion of a system. The ferrite logic device belongs to the all-magnetic class of logic circuits. The FLO device is novel in that it makes use of a dual or bimaterial ferrite composition in one physical ceramic body. This bimaterial feature, coupled with its potential for relatively high speed operation, makes it attractive for high reliability applications. (Maximum speed of operation approximately 50 kHz.)

Baer, J. A.↗
NASA NTRS1977

Oblique wing transonic transport configuration development

Studies of transport aircraft designed for boom-free supersonic flight show the variable sweep oblique wing to be the most efficient configuration for flight at low supersonic speeds. Use of this concept leads to a configuration that is lighter, quieter, and more fuel efficient than symmetric aircraft designed for the same mission. Aerodynamic structural, weight, aeroelastic and flight control studies show the oblique wing concept to be technically feasible. Investigations are reported for wing planform and thickness, pivot design and weight estimation, engine cycle (bypass ratio), and climb, descent and reserve fuel. Results are incorporated into a final configuration. Performance, weight, and balance characteristics are evaluated. Flight control requirements are reviewed, and areas in which further research is needed are identified.

Source record↗
NASA NTRS1999

Changes in Body Inertia During Bed Rest Studies

Development of effective exercise countermeasures is crucial for long duration human space flight. To analyze the mechanical effects of a particular exercise on the musculoskeletal system, the inertial properties of segments of the body must be quantified. Since bone mineral density loss is related to the lack of mechanical stress and strain on the skeletal system, physical analysis can be very useful for countermeasure evaluation.

Todd, Beth A.↗
NASA NTRS1984

Space Station concept development group studies

The NASA study activities in preparation for a Space Station began in the early 1970's. The early studies included many in-house NASA and contracted studies. A group of representatives from all the NASA Centers, titled the Space Station Concept Development Group (CDG) was involved in the studies which led to the initiation of the Space Station Program. The CDG studies were performed over a period of approximately one year and consisted of four phases. The initial phase had the objective to determine the functions required of the station as opposed to a configuration. The activities of the second phase were primarily concerned with a sizing of the facilities required for payloads and the resources necessary to support these mission payloads. The third phase of studies was designed to develop a philosophical approach to a number of areas related to autonomy, maintainability, operations and logistics, and verification. The fourth phase of the study was to be concerned with configuration assessment activities.

Powell, L. E.↗
NASA NTRS1991

A numerical study of thunderstorm electrification - Model development and case study

A numerical model was developed for examining the thunderstorm electrification process in which it is assumed that the electrification is entirely due to noninductive charge transfer between colliding ice crystals and hail. Since this ice-hail charge mechanism is very dependent on particle sizes and distributions, an explicit microphysical framework is used. To maintain simplicity, the electrification model is kinematic; thus the temperature and velocity fields are input into the electrification model. The cloud model of Taylor (1989) was used to generate the temperature and velocity fields to examine the July 19, 1981, Cooperative Convective Precipitation Experiment thundercloud. Using these fields, the electrification model produced time-dependent ice particle concentrations, radar reflectivities, charge, and vertical electric field distributions in good general agreement with those observed. The model produced a maximum electric field strength of 1.27 kV/cm, which is on the order of that needed for lightning initiation, and this maximum occurred very close to the time of the observed discharge. Thus, the ice-hail charge mechanism appears to have played an important role in the electrical development of the July 19 cloud.

Norville, K.↗
NASA NTRS1994

Study of development and utilization of a multipurpose atmospheric corrosion sensor

There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted.

Diwan, Ravinder M.↗
NASA NTRS1980

Study to develop improved fire resistant aircraft passenger seat materials

The Phase 3 study of the NASA 'Improved Fire Resistant Aircraft Seat Materials' involved fire tests of improved materials in multilayered combinations representative of cushion configurations. Tests were conducted to determine their thermal, smoke, and fire resistance characteristics. Additionally, a 'Design Guideline' for Fire Resistant Passenger Seats was written outlining general seat design considerations. Finally, a three-abreast 'Tourist Class' passenger seat assembly fabricated from the most advanced fire-resistant materials was delivered.

Duskin, F. E.↗
NASA NTRS2002

Preliminary Thermal-Mechanical Sizing of Metallic TPS: Process Development and Sensitivity Studies

The purpose of this research was to perform sensitivity studies and develop a process to perform thermal and structural analysis and sizing of the latest Metallic Thermal Protection System (TPS) developed at NASA LaRC (Langley Research Center). Metallic TPS is a key technology for reducing the cost of reusable launch vehicles (RLV), offering the combination of increased durability and competitive weights when compared to other systems. Accurate sizing of metallic TPS requires combined thermal and structural analysis. Initial sensitivity studies were conducted using transient one-dimensional finite element thermal analysis to determine the influence of various TPS and analysis parameters on TPS weight. The thermal analysis model was then used in combination with static deflection and failure mode analysis of the sandwich panel outer surface of the TPS to obtain minimum weight TPS configurations at three vehicle stations on the windward centerline of a representative RLV. The coupled nature of the analysis requires an iterative analysis process, which will be described herein. Findings from the sensitivity analysis are reported, along with TPS designs at the three RLV vehicle stations considered.

Poteet, Carl C.↗
NASA NTRS1999

Interferometer Development for Study of Interactions between Flames on Parallel Solid Surfaces

The interactions between flames spreading over parallel solid sheets of paper are being studied in normal gravity and in microgravity. This geometry provides interesting opportunities to study the interaction of radiative and diffusive transport mechanisms on the spread process. These transport mechanisms are changed when the flame interacts with other flames. Most practical heterogeneous combustion processes involve interacting discrete burning fuel elements, consequently, the study of these interactions is of practical significance. Owing largely to this practical importance, flame interactions have been an area of active research, however microgravity research has been largely limited to droplets. Consideration of flame spread over parallel solid surfaces has been limited to 1-g studies. To study the conductive transport in these flames, an interferometer system has been developed for use in the drop tower. The system takes advantage of a single beam interferometer: Point Diffraction Interferometry (PDI) which uses a portion of the light through the test section to provide the reference beam. Like other interferometric and Schlieren systems, it is a line of sight measurement and is subject to the usual edge and concentration effects. The advantage over Schlieren and shearing interferometry systems is that the fringes are lines of constant index of refraction rather than of its gradient so the images are more readily interpreted. The disadvantage is that it is less able to accommodate a range of temperature gradients.

Goldmeer, J. S.↗
NASA NTRS1976

Development and study of chemical vapor deposited tantalum base alloys

A technique for the chemical vapor deposition of alloys was developed. The process, termed pulsing, involves the periodic injection of reactant gases into a previously-evacuated reaction chamber where they blanket the substrate almost instantaneously. Formation of alternating layers of the alloy components and subsequent homogenization allows the formation of an alloy of uniform composition with the composition being determined by the duration and relative numbers of the various cycles. The technique has been utilized to produce dense alloys of uniform thickness and composition (Ta- 10 wt % W) by depositing alternating layers of Ta and W by the hydrogen reduction of TaCl5 and WCl6. A similar attempt to deposit a Ta - 8 wt % W - 2 wt% Hf alloy was unsuccessful because of the difficulty in reducing HfCl4 at temperatures below those at which gas phase nucleation of Ta and W occurred.

Meier, G. H.↗
NASA NTRS2000

Interactive Software System Developed to Study How Icing Affects Airfoil Performance (Phase 1 Results)

SmaggIce (Surface Modeling and Grid Generation for Iced Airfoils), which is being developed at the NASA Glenn Research Center at Lewis Field, is an interactive software system for data probing, boundary smoothing, domain decomposition, and structured grid generation and refinement. All these steps are required for aerodynamic performance prediction using structured, grid-based computational fluid dynamics (CFD), as illustrated in the following figure. SmaggIce provides the underlying computations to perform these functions, as well as a graphical user interface to control and interact with them, and graphics to display the results.

Choo, Yung K.↗