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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
DOE OSTI2022

Enabling Extended-Term Simulation of Power Systems with High PV Penetration. Final Report

This is the final Technical Report for DOE-SETO Project Award # DE-EE0036461. The goal of this project is to advance the understanding of the grid impact of high penetration of photovoltaic (PV) generation by developing novel numerical methods to solve the differential algebraic equations (DAEs) that define power systems. This will overcome the limitations of current software packages – namely that they only consider fast dynamics over brief time periods. The work presented in this final project report covers results over the entire period of the project. This includes results on model development, code development for the PST repository, datasets in the PST repository, algorithm development and results from variable time-step simulations, development and results from multirate simulations, and sensitivity analysis of key parameter in variable time-step methods. In addition, this report discusses project outreach activities to stakeholders, and a summary of project products. Also covered in this final report is the writing of two conference papers (one of which has already been accepted) and a journal paper. In addition, the updating of two inverter models (both grid forming and grid following) to be compatible with the latest version of PST software is discussed.

14 SOLAR ENERGY↗
NASA NTRS1971

Mariner Mars 1969 - Atmospheric results

Mars atmospheric data from Mariner flights, discussing north polar haze, bright surface features morphology, multiring structures and water vapor exchange

Leighton, R. B.↗
NASA NTRS1972

Differentiation and volcanism in the lunar highlands - Photogeologic evidence and Apollo 16 implications.

Study of materials of possible volcanic origin in the lunar highlands, including highland plains materials, materials forming closely spaced hills in which summit furrows and chains of craters are common, and materials forming closely spaced hills (some of which parallel the lunar grid) on which summit furrows and chain craters are rare. The highland plains materials probably are basaltic lavas with less Fe and Ti than the mare plains materials. The two hilly units appear to consist of materials that, if volcanic, were more viscous in the molten state than any of the lunar plains units; thus these materials may be significantly enriched in felsic components. Most of the highland materials of possible volcanic origin formed after the Imbrium multiring basin but before mare material completed flooding parts of the moon; they therefore postdate accretion of the moon and may represent several episodes of pre-mare volcanism.

Trask, n. J.↗
NASA NTRS1973

Geologic setting of Apollo 16

Prior to the Apollo 16 mission, the materials of the Cayley Plains and the Descartes Mountains were thought to be mostly of volcanic origin. Rock and soil samples from these regions strongly suggest, however, that they may be products of multiring basin forming impacts, although minor local volcanism is not precluded. The smooth planar surfaces may have been formed initially by Imbrium ejecta which flowed into topographic lows at the distal margins of the lineated Fra Mauro ejecta. It is emphasized, however, that the rocks and soils returned from the Apollo 16 site cannot necessarily be considered representative of the lunar crust in the Descartes region from which they were collected.

Hodges, C. A.↗
NASA NTRS1974

Lunar basin formation and highland stratigraphy

Multiring impact basins, formed after solidification of the lunar crust, account for most or all premare regional deposits and structures expressed in the lunar landscape and for major topographic and gravity variations. A fresh basin has two or more concentric mountain rings, a lineated ejecta blanket, and secondary impact craters. Crackled material on the floor may be impact melt. The ejecta blanket was emplaced at least partly as a ground-hugging flow and was probably hot. A suggested model of basin formation is that the center lifts up and the rings form by inward collapse during evisceration. The resulting basin is shallow and has a central uplift of the mantle. This results in a central gravity high and a ring low. Later flooding by mare basalt has since modified most near side basins. Highland deposits of plains, furrowed and pitted terrain, and various hills, domes, and craters that were interpreted before the Apollo missions as being volcanic can now be interpreted as being basin related.

Howard, K. A.↗
NASA NTRS1974

Multiringed basins - Illustrated by Orientale and associated features

Geologic mapping and photographs of the Orientale multiring basin are studied as to origin, size, and nature and distribution of ejecta. Six facies of ejecta are observed around the Cordillera Mountains: concentric, radial, smooth plains, grooved, secondary impact craters, and fissured. Transport of these ejecta occurred by block gliding, landsliding, debris flow, and possibly by base surge, viscous flow, and ballistic ejection. The ejecta are mainly clastic types, but melts and annealed breccias are expected to be abundant. Mixing of ejecta and substrate materials must have occurred; compositions of the ejecta are probably zoned laterally and vertically.

Moore, H. J.↗
NASA NTRS1979

High-pressure liquid chromatography of aromatic amines

Analysis made on commercially available liquid chromatograph demonstrates high-pressure liquid chromatographic conditions for separation of approximately 50 aromatic amines ranging from simple aniline derivatives to complex multiring di- and tri-amines.

Young, P. R.↗
NASA NTRS1978

A single user efficiency measure for evaluation of parallel or pipeline computer architectures

A precise statement of the relationship between sequential computation at one rate, parallel or pipeline computation at a much higher rate, the data movement rate between levels of memory, the fraction of inherently sequential operations or data that must be processed sequentially, the fraction of data to be moved that cannot be overlapped with computation, and the relative computational complexity of the algorithms for the two processes, scalar and vector, was developed. The relationship should be applied to the multirate processes that obtain in the employment of various new or proposed computer architectures for computational aerodynamics. The relationship, an efficiency measure that the single user of the computer system perceives, argues strongly in favor of separating scalar and vector processes, sometimes referred to as loosely coupled processes, to achieve optimum use of hardware.

Jones, W. P.↗
NASA NTRS1978

Closed loop models for analyzing the effects of simulator characteristics

The optimal control model of the human operator is used to develop closed loop models for analyzing the effects of (digital) simulator characteristics on predicted performance and/or workload. Two approaches are considered: the first utilizes a continuous approximation to the discrete simulation in conjunction with the standard optimal control model; the second involves a more exact discrete description of the simulator in a closed loop multirate simulation in which the optimal control model simulates the pilot. Both models predict that simulator characteristics can have significant effects on performance and workload.

Baron, S.↗
NASA NTRS1979

Charting the southern seas - The evolution of the lunar Mare Australe

Mare Australe has been subjected to at least four major episodes of basalt eruption ranging in age from early Imbrian to Eratosthenian. The basalts were emplaced largely in flood eruptions from at least 197 vents located on post-basin impact crater floors. The youngest basalts occur in an annulus near the outer edge of the basin. The fill thickness apparently reflects a multiring structure for the post-impact morphology of the Australe basin; the thin basaltic fill was not sufficient a load to produce tectonic rilles, but mare ridges are present and exhibit a prominent north-south alignment.

Whitford-Stark, J. L.↗
NASA NTRS1980

Ridge systems of Caloris - Comparison with lunar basins

It has been found that the wrinkle ridge systems of the Caloris basin on Mercury display many of the traits which are characteristic of ridges in the mare-filled lunar multiring basins. The considered investigation is concerned with the ridge systems within the Caloris basin on Mercury, and implications for the origin of ridges within basins on both Mercury and the moon. The observed features are found to indicate that the early evolution of Caloris was similar to that of lunar mascon basins. The morphology of ridges within Caloris compares favorably with lunar ridges when viewed on similar resolution earth-based lunar photographs. Ridges in Caloris occur from 1000 to 1320 km diameter range, and are situated within the boundary delineated by topographic benches in the northeastern and southeastern parts of the basin. The orientation of Caloris ridges is more dominantly concentric than ridge orientations in lunar basins.

Maxwell, T. A.↗
NASA NTRS1981

The excavation stage of basin formation - A qualitative model

One of the most complex problems in planetary geology and geophysics is the determination of the nature of the impact cratering processes at scales of tens to thousands of kilometers that produce the complex morphological structures of multiring basins. The cratering process is frequently considered to be divided into three stages, including a short high-pressure stage of initial contact between the projectile and the planetary crust, a longer excavation or cratering flow stage culminating in the formation of a transient crater, and a still longer modification stage during which the transient crater is modified into the observed final geologic form. The transient crater may be considered as the initial boundary condition of the modification stage. In the present investigation, the nature of the transient crater is indicated by the cratering flow field determined from numerical simulations of the excavation stage. Attention is given to empirical and theoretical scaling.

Croft, S. K.↗
NASA NTRS1982

The structure and evolution of ancient impact basins on Mars

It is pointed out that characteristic styles of degradation and modification of obvious Martian basins make it possible to recognize more subtle expressions. This approach is seen as providing not only additional basins to the existing inventory but also fundamental clues for initial impact basin structure and stratigraphy. It also reveals the long-lasting influence of basin formation on the crust of Mars in spite of extensive erosion and resurfacing. Consideration is given to five clear examples of modified impact basins, and regions around each that have undergone similar processes (fracturing, collapse, channeling) are delineated. These processes among the different basins are then compared, and similar zones of modification are correlated with concentric basin rings. Consideration is then given to the implications of these observations for current models of basin formation and to the role of impact basins in controlling regional tectonics. The results indicate that large multiring impact scars leave a major but sometimes subtle imprint on the geologic structure of stable crustal regions on Mars.

Schultz, P. H.↗
NASA NTRS1982

Craters and basins on Ganymede and Callisto - Morphological indicators of crustal evolution

The morphologic characteristics of craters and palimpsests on Ganymede and Callisto are surveyed, and the crustal properties of these satellites and the evolution of the properties are studied. The morphology of bowl-shaped craters, smooth-floored craters, craters without central peaks, craters with central pits, chain craters on Callisto, the Gilgamesh and Western Equatorial Basins on Ganymede, crater palimpsests and penepalimpsests, multiring structures on Callisto, and the Galileo Regio rimmed furrow system on Ganymede are described individually. The crustal evolution is addressed by examining the development of the Galileo Regio system, the distribution of crater retention ages, the record of ray clusters, the thermal history of the lithosphere of Ganymede, and the origin of the central pits. It is suggested that as the lithosphere of each satellite cooled and thickened, crater retentivity spread as a wave from the polar regions and the antapex toward the apex; at any given location, progressively larger craters were retained with the passage of time.

Passey, Q. R.↗
NASA NTRS1984

Ring spacing of Mercurian multi-ring basins and basin ring formation

Recent systematic mapping of Mercury has revealed many ancient and previously unrecognized multiring basins. The population of these basins now stands at 20, possibly is as large as 25, and includes at least 76 measurable rings. From the new data base, we present some systematics of basin ring spacing on Mercury, compare them with similar data for the Moon, and draw some preliminary conclusions on conditions of ring formation for basins on the terrestrial planets.

Pike, R. J.↗