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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

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DOE OSTI2018

Evaluation of Spent Fuel Disposition in Crystalline Rocks: FY18 Progress Report

The U.S. Department of Energy Office of Spent Fuel Waste Disposition (SFWD) established in fiscal year 2010 (FY10) the Spent Fuel Waste Science & Technology (SFWST) Program (formerly the Used Fuel Disposition Campaign - UFDC) program to conduct the research and development (R&D) activities related to storage, transportation and disposal of used nuclear fuel and high level nuclear waste. The Mission of the SFWST is: To identify alternatives and conduct scientific research and technology development to enable storage, transportation and disposal of used nuclear fuel and wastes generated by existing and future nuclear fuel cycles. The work package of Crystalline Disposal R&D directly supports the following SFWST objectives: Develop a fundamental understanding of disposal system performance in a range of environments for potential wastes that could arise from future nuclear fuel cycle alternatives through theory, simulation, testing, and experimentation. ; Develop a computational modeling capability for the performance of storage and disposal options for a range of fuel cycle alternatives, evolving from generic models to more robust models of performance assessment. The objective of the Crystalline Disposal R&D control account is to advance our understanding of long-term disposal of used fuel in crystalline rocks and to develop necessary experimental and computational capabilities to evaluate various disposal concepts in such media. Significant progress has been made in FY18 in both experimental and modeling arenas in evaluation of used fuel disposal in crystalline rocks, especially in model demonstration using field data. The work covers a wide range of research topics identified in the R&D plan. The major accomplishments are summarized.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2024

Advanced Guide to Understanding Power System Model Results for Long-Term Resource Plans

This guide is for public utility commission staff, state energy office staff, and other stakeholders who review model results for utility integrated resource plans (IRPs). It builds on the "Beginner's Guide to Understanding Power System Model Results for Long-Term Resource Plans," and delves into more advanced topics that were not included or not fully covered in the beginner's guide. The topics included here are evolving and may or may not be important to the resource plan you are evaluating. Due to limitations in resources, it's also not possible to give the highest level of detail or attention to every topic within a plan. An important part of planning for an uncertain future involves deciding which topics deserve the most focus and resources. It's all about prioritizing efforts where they will have the most impact or be most beneficial despite uncertainties ahead. As with the beginner's guide, we intend for this guide to help improve decision-making in the electricity planning process by strengthening understanding and dialogue between electricity system planners and relevant stakeholders. The following information is designed to allow you to better engage in the planning process by evaluating results, asking questions, and thinking through what is most important. We allocate significant discussion in the guide to electricity demand evolution, demand-side resources, and resource adequacy. These topics have garnered increasing attention, hence their prominence in this guide. Other topics are also presented, but their incorporation into the planning process might vary based on interest and relevance. The absence of certain topics doesn't diminish their importance; rather, it reflects the reality that in planning, trade-offs necessitate prioritizing certain aspects over others.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2026

Editorial: Predicting near-earth space environment: new perspective and capabilities in the AI age

Editorial on the Research Topic Predicting near-earth space environment: new perspective and capabilities in the AI age The near-Earth space environment is not only an operational hazard for space missions, but also a scientific laboratory for advancing our understanding and prediction of space plasma populations. This Research Topic is organized around three interconnected themes: observational datasets, machine-learning (ML) model development, and the discovery of new physical insights through those models. Its primary goal is to highlight the emerging capabilities in space environment prediction that are enabled, or will be enabled, by integrating advanced techniques—including AI/ML methods—with long-term curated datasets.

58 GEOSCIENCES↗

NASA NTRS1973

On the properties of matter in neutron stars

A qualitative description of the interior of a neutron star is presented, giving attention also to the validity of the 'isotropic fluid' approximation. The atmosphere and surface of a neutron star are considered together with aspects concerning nuclear and solid state physics in the crust, the liquid interior, the hyperon core, neutron star models, and pulsar observations. Accretion processes are also investigated, taking into account such topics as the Eddington limit, accretion rates, the death of pulsars, changes of the surface composition of neutron stars by accretion, questions of X-ray emission, and aspects of gamma radiation emission.

Boerner, G.↗

NASA NTRS1975

Optimization of MLS receivers for multipath environments

A receiver is designed for aircraft (A/C), which, as a component of the proposed Microwave Landing System (MLS), is capable of optimal performance in the multipath environments found in air terminal areas. Topics discussed include: the angle-tracking problem of the MLS receiver; signal modeling; preliminary approaches to optimal design; suboptimal design; and simulation study.

Mcalpine, G. A.↗

NASA NTRS1976

Summary of nozzle-exhaust plume flowfield analyses performed in support of space shuttle applications

Results are summarized of various analyses of the exhaust plumes of the space shuttle. Specific topics discussed included: the development of the two-phase plume flow field model, including finite rate chemistry and free molecular effects; analyses of exhaust plume simulation studies; verification of the analytical two-phase plume flow field model; and complete documentation of the two-phase plume computer code.

Smith, S. D.↗

NASA NTRS1978

Conference on Helicopter Structures Technology, Moffett Field, Calif., November 16-18, 1977, Proceedings

Work on advanced concepts for helicopter designs is reported. Emphasis is on use of advanced composites, damage-tolerant design, and load calculations. Topics covered include structural design flight maneuver loads using PDP-10 flight dynamics model, use of 3-D finite element analysis in design of helicopter mechanical components, damage-tolerant design of the YUH-61A main rotor system, survivability of helicopters to rotor blade ballistic damage, development of a multitubular spar composite main rotor blade, and a bearingless main rotor structural design approach using advanced composites.

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NASA NTRS1980

Black holes, quasars, and the universe /2nd edition/

Topics of astronomy are discussed in terms of black holes, galaxies, quasars, and models of the universe. Black holes are approached through consideration of stellar evolution, white dwarfs, supernovae, neutron stars, pulsars, the event horizon, Cygnus X-1, white holes, and worm holes. Attention is also given to radio waves from high speed electrons, the radiation emitted by quasars, active galaxies, galactic energy sources, and interpretations of the redshift. Finally, the life cycle of the universe is deliberated, along with the cosmic time scale, evidence for the Big Bang, and the future of the universe.

Shipman, H. L.↗

NASA NTRS1983

Aeronomy of the inner planets

Recent progress concerning the thermospheres of Venus and Mars is reviewed in this report. A dramatic advance in our understanding of the upper atmosphere and ionosphere of Venus has occurred during the 1979-82 quadrennium, and was primarily due to the large amount of data generated by the Pioneer Venus mission. Progress on Mars has been rather modest and has stemmed from theoretical modeling efforts related to the 1976 Viking observations. This report covers the following topics: the thermosphere and ionosphere of Mars, the thermosphere of Venus, some aspects of the solar wind-ionosphere interaction of Venus, the dayside ionosphere of Venus including both composition and energetics, and the nightside ionosphere of Venus.

Cravens, T. E.↗

NASA NTRS1983

Stereo imaging with spaceborne radars

Stereo viewing is a valuable tool in photointerpretation and is used for the quantitative reconstruction of the three dimensional shape of a topographical surface. Stereo viewing refers to a visual perception of space by presenting an overlapping image pair to an observer so that a three dimensional model is formed in the brain. Some of the observer's function is performed by machine correlation of the overlapping images - so called automated stereo correlation. The direct perception of space with two eyes is often called natural binocular vision; techniques of generating three dimensional models of the surface from two sets of monocular image measurements is the topic of stereology.

Leberl, F.↗

NASA NTRS1986

International Symposium on Remote Sensing of Environment, Fourth Thematic Conference: Remote Sensing for Exploration Geology, San Francisco, CA, April 1-4, 1985, Proceedings. Volumes 1 & 2

State of the art applications of remote sensing in geological exploration programs are discussed along with research and development activities aimed at increasing the future capabilities of this technology for exploration geology. The topics considered include: technical issues in the state of the art; regional exploration models; remote sensing applications for hydrocarbon exploration; commercialization of remote sensing satellites; and data integration. Also addressed are: remote sensing applications for mineral exploration; geobotanical and environmental remote sensing; image processing techniques and applications; advanced sensors, radar, and airborne systems; and engineering, logistics, and marine applications.

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NASA NTRS1987

Supercomputing in Aerospace

Topics addressed include: numerical aerodynamic simulation; computational mechanics; supercomputers; aerospace propulsion systems; computational modeling in ballistics; turbulence modeling; computational chemistry; computational fluid dynamics; and computational astrophysics.

Kutler, Paul↗

NASA NTRS1986

Expert systems and simulation models; Proceedings of the Seminar, Tucson, AZ, November 18, 19, 1985

The seminar presents papers on modeling and simulation methodology, artificial intelligence and expert systems, environments for simulation/expert system development, and methodology for simulation/expert system development. Particular attention is given to simulation modeling concepts and their representation, modular hierarchical model specification, knowledge representation, and rule-based diagnostic expert system development. Other topics include the combination of symbolic and discrete event simulation, real time inferencing, and the management of large knowledge-based simulation projects.

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NASA NTRS1986

Cosmic dust and space debris; Proceedings of the Topical Meetings and Workshop 6 of the 26th COSPAR Plenary Meeting, Toulouse, France, June 30-July 11, 1986

These proceedings encompass topics in the fields of extraterrestrial material samples, IRAS solar system and dust model results, and earth orbit debris. Attention is given to chemical fractionation during high velocity impact, particle deceleration and survival in multiple thin foil targets, and IRAS studies of asteroids, comets, cometary tails, the zodiacal background, and the three-dimensional modeling of interplanetary dust. Also discussed are the evolution of an earth orbit debris cloud, orbital debris due to future space activities, collision probabilities in geosynchronous orbits, and a bitelescopic survey of low altitude orbital debris.

Mcdonnell, J. A. M.↗

NASA NTRS1991

The importance of momentum transfer in collision-induced breakups in low Earth orbit

Although there is adequate information on larger objects in low Earth orbit, specifically those objects larger than about 10 cm in diameter, there is little direct information on objects from this size down to 1 mm. Yet, this is the sized regime where objects acting as projectiles represent the ability to seriously damage or destroy a functioning spacecraft if they collide with it. The observed consequences of known collisional breakups in orbit indicates no significant momentum transfer in the resulting debris cloud. The position taken in this paper is that this is an observational selection effect: what is seen in these events is an explosion-like breakup of the target structure arising from shock waves introduced into the structure by the collision, but one that occurs significantly after the collision processes are completed; the collision cloud, in which there is momentum transfer, consists of small, unobserved fragments. Preliminary computations of the contribution of one known collisional breakup, Solwind at 500 km in 1985, and Cosmos 1275 in 1981, assume no momentum transfer on breakup and indicate that these two events are the dominant contributors to the current millimeter and centimeter population. A different story would emerge if momentum transfer was taken into account. The topics covered include: (1) observation of on-orbit collisional breakups; (2) a model for momentum transfer; and (3) velocity space representation of breakup clouds.

Reynolds, Robert C.↗

NASA NTRS1991

Models of planetary rings

The Voyager occultations provide several uniform and high quality data sets for Saturn, Uranus, and Neptune. These data are intercompared, and theoretical models for the particle sizes and the particle transport are developed. The major topics covered include: ring size distribution, torques and resonances, and satellite wakes.

Esposito, L. W.↗

NASA NTRS1984

Stable direct adaptive control of linear infinite-dimensional systems using a command generator tracker approach

The topics are presented in view graph form and include the following: an adaptive model following control; adaptive control of a distributed parameter system (DPS) with a finite-dimensional controller; a direct adaptive controller; a closed-loop adaptively controlled DPS; Lyapunov stability; the asymptotic stability of the closed loop; and model control of a simply supported beam.

Balas, Mark↗

NASA NTRS1993

Engine exhaust characteristics evaluation in support of aircraft acoustic testing

NASA Dryden Flight Research Facility and NASA Langley Research Center completed a joint acoustic flight test program. Test objectives were (1) to quantify and evaluate subsonic climb-to-cruise noise and (2) to obtain a quality noise database for use in validating the Aircraft Noise Prediction Program. These tests were conducted using aircraft with engines that represent the high nozzle pressure ratio of future transport designs. Test flights were completed at subsonic speeds that exceeded Mach 0.3 using F-18 and F-16XL aircraft. This paper describes the efforts of NASA Dryden Flight Research Facility in this flight test program. Topics discussed include the test aircraft, setup, and matrix. In addition, the engine modeling codes and nozzle exhaust characteristics are described.

Ennix, Kimberly A.↗