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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Modeling energy flow and nutrient cycling in natural semiarid grassland ecosystems with the aid of thematic mapper data

Energy flow and nutrient cycling were modeled as affected by herbivory on selected intensive sites along gradients of precipitation and soils, validating the model output by monitoring selected parameters with data derived from the Thematic Mapper (TM). Herbivore production was modeled along the gradient of soils and herbivory, and validated with data derived from TM in a spatial data base.

Lewis, James K.↗
NASA NTRS2013

Measurement of Electromagnetic Energy Flow Through a Sparse Particulate Medium: A Perspective

First-principle analysis of the functional design of a well-collimated radiometer (WCR) reveals that in general, this instrument does not record the instantaneous directional flow of electromagnetic energy. Only in special cases can a sequence of measurements with a WCR yield the magnitude and direction of the local time-averaged Poynting vector. Our analysis demonstrates that it is imperative to clearly formulate the physical nature of the actual measurement afforded by a directional radiometer rather than presume desirable measurement capabilities. Only then can the directional radiometer be considered a legitimate part of physically based remote sensing and radiation-budget applications. We also emphasize the need for a better understanding of the nature of measurements with panoramic radiometers.

directional radiometry↗
NASA NTRS1972

Magnetic energy flow in the solar wind.

Discussion of the effect of rotation (tangential flow) of the solar wind on the conclusions of Whang (1971) suggesting an increase in the solar wind velocity due to the conversion of magnetic energy to kinetic energy. It is shown that the effect of the rotation of the sun on the magnetic energy flow results in most of the magnetic energy being transported by magnetic shear stress near the sun.

Modisette, J. L.↗
DOE OSTI2024

Orienting Strained Interfaces designed to Direct Energy Flow (Final Technical Report)

This proposal aims to establish a transformative paradigm for oxide heterostructures with an exceptionally large number of interfaces designed to direct energy flow through controlled interface orientation, enabling fast ion transport. A primary focus is on unveiling the key role of interfacial strain in oxygen ion migration at low temperatures. The central challenge is to create, understand, utilize self-assembled vertical heteroepitaxial nanostructures with the goal of obtaining and understanding fast ion transport properties by modulating interfacial strain. The specific objectives are: (1) to synthesize multilayer thin films and vertical heteroepitaxial nanostructures with fluorite Gd-doped CeO 2 (GDC) and bixbyite RE 2 O 3 (RE = Y and Sm), (2) to evaluate the interfacial strain states under various temperatures and ambient conditions, (3) to understand the effect of interfacial strain on ionic conductivity of the proposed nanostructures, (4) to understand the three-dimensional (3D) atomic structure of the proposed material design and interface phenomena at the atomic scale.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Towards Energy-Positive Buildings through a Quality-Matched Energy Flow Strategy

Current strategies for net-zero buildings favor envelopes with minimized aperture ratios and limiting of solar gains through reduced glazing transmittance and emissivity. This load-reduction approach precludes strategies that maximize on-site collection of solar energy, which could increase opportunities for net-zero electricity projects. To better leverage solar resources, a whole-building strategy is proposed, referred to as “Quality-Matched Energy Flows” (or Q-MEF): capturing, transforming, buffering, and transferring irradiance on a building’s envelope—and energy derived from it—into distributed end-uses. A mid-scale commercial building was modeled in three climates with a novel Building-Integrated, Transparent, Concentrating Photovoltaic and Thermal fenestration technology (BITCoPT), thermal storage and circulation at three temperature ranges, adsorption chillers, and auxiliary heat pumps. BITCoPT generated electricity and collected thermal energy at high efficiencies while transmitting diffuse light and mitigating excess gains and illuminance. The balance of systems satisfied cooling and heating demands. Relative to baselines with similar glazing ratios, net electricity use decreased 71% in a continental climate and 100% or more in hot-arid and subtropical-moderate climates. Total EUI decreased 35%, 83%, and 52%, and peak purchased electrical demands decreased up to 6%, 32%, and 20%, respectively (with no provisions for on-site electrical storage). Decreases in utility services costs were also noted. These results suggest that with further development of electrification the Q-MEF strategy could contribute to energy-positive behavior for projects with similar typology and climate profiles.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Power counting energy flow polynomials

Power counting is a systematic strategy for organizing collider observables and their associated theoretical calculations. In this paper, we use power counting to characterize a class of jet substructure observables called energy flow polynomials (EFPs). EFPs provide an overcomplete linear basis for infrared-and-collinear safe jet observables, but it is known that in practice, a small subset of EFPs is often sufficient for specific jet analysis tasks. By applying power counting arguments, we obtain linear relationships between EFPs that hold for quark and gluon jets to a specific order in the power counting. We test these relations in the parton shower generator Pythia, finding excellent agreement. Power counting allows us to truncate the basis of EFPs without affecting performance, which we corroborate through a study of quark-gluon tagging and regression.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1977

The relationship of energy flow at the magnetopause to geomagnetic activity

Properties of the energetic electron (E greater than or approximately equal to 200 keV) magnetopause layer along the distant magnetotail have been studied with Caltech instrumentation aboard IMP-8 for approximately 60 spacecraft orbits. The cross-sectional area of the layer appears to increase by a factor of approximately 5 with increasing geomagnetic activity, and the average unidirectional electron flux within the layer increases by a factor of approximately 4. The energy carried by electrons greater than or approximately equal to 200 keV ranges from approximately 10 to the 14th ergs per second to approximately 10 to the 15th ergs per second. Extrapolation to include all electrons greater than 1 keV suggests total energy flow ranging from approximately 3 x 10 to the 15th ergs per second at quiet times to approximately 5 x 10 to the 18th ergs per second at magnetically disturbed times.

Baker, D. N.↗
NASA NTRSDate not supplied

Tracing the Cosmic Energy Flow with Parker Solar Probe: Universal Processes

Heliophysics is inherently interdisciplinary, born from multiple subjects to understand how the Sun interacts with its surrounding environment. Heliophysicists and Astrophysicists seldom exchange ideas since the scientific infrastructure partitions research areas by spatial location in the cosmos. Parker Solar Probe (PSP) is sending back puzzling information in regions we have never been before, presenting an opportunity to search for answers in non-traditional ways that are inherently cross-disciplinary. The fundamental processes that govern the physics of the universe, such as wave-particle interactions, turbulence, magnetic reconnection, and shocks, are mechanisms to study cosmic energy flow. We present PSP observations that may enable us to assess the universality of these fundamental processes in – and across boundaries of –various space and astrophysical regimes. Specifically, we focus on the exotic shapes of proton velocity distribution functions and subsequent evolution leading to multi-scale wave generation and particle acceleration. We welcome ideas, tools, and methodologies from all disciplines to understand the systems of systems governing our universe.

J L Verniero↗
NASA NTRS1987

Bidirectional control system for energy flow in solar powered flywheel

An energy storage system for a spacecraft is provided which employs a solar powered flywheel arrangement including a motor/generator which, in different operating modes, drives the flywheel and is driven thereby. A control circuit, including a threshold comparator, senses the output of a solar energy converter, and when a threshold voltage is exceeded thereby indicating the availability of solar power for the spacecraft loads, activates a speed control loop including the motor/generator so as to accelerate the flywheel to a constant speed and thereby store mechanical energy, while also supplying energy from the solar converter to the loads. Under circumstances where solar energy is not available and thus the threshold voltage is not exceeded, the control circuit deactivates the speed control loop and activates a voltage control loop that provides for operation of the motor as a generator so that mechanical energy from the flywheel is converted into electrical energy for supply to the spacecraft loads.

Nola, Frank J.↗
NASA NTRS2016

Design and Experimental Evaluation of Flextensional-Cantilever Based Piezoelectric Transducers for Flow Energy Harvesting

Cantilever type piezoelectric harvesters, such as bimorphs, are typically used for vibration induced energy harvesting. However, a major drawback of a piezoelectric bimorph is its brittle nature in harsh environments, resulting in short life-times as well as output power degradation. The emphasis in this work is to design robust, highly efficient piezoelectric harvesters that are capable of generating electrical power in the milliwatt range. Various harvesters have been modeled, designed and prototyped, and the flextensional actuator based harvester, where the metal cantilever is mounted and coupled between two flextensional actuators, was found to be a viable alternative to the cantilever type piezoelectric harvesters. Preliminary tests showed that these devices equipped with 5x5x36 mm two piezoelectric PZT stacks can produce greater than 50 mW of power under air flow induced vibrations.

fluid structure interaction↗
NASA NTRSDate not supplied

Evaluating Twenty-Year Trends in Earth’s Energy Flows from Observations

Recent satellite and ocean in-situ observations indicate a doubling of Earth’s Energy Imbalance (EEI) since 2005 that is a consequence of anthropogenic forcing, internal variability, and climate feedbacks. In this study, we follow-up with an assessment of how other components of Earth’s energy budget have changed since 2000 and how well these can be tracked. Specifically, we use top-of-atmosphere and surface observations from the Clouds and the Earth’s Radiant Energy System (CERES) and calculations of atmospheric divergence of energy transport from ERA-5 to determine the change in total surface flux along with its radiative and turbulent heat flux components. We also assess trends in ocean heat uptake for different ocean layers using various ocean reanalysis datasets. We compare trends derived using various observational and modeling approaches to assess how robust the derived trends are. Our analysis is restricted to global, hemispheric and regional spatial scales and annual mean and seasonal timescales.

CERES↗
NASA NTRS1988

The temperature structure, mass, and energy flow in the corona and inner solar wind

Remote-sensing and in situ data are used to constrain a radiative energy balance model in order to study the radial variations of coronal temperatures, densities, and outflow speeds in several types of coronal holes and in an unstructured quiet region of the corona. A one-fluid solar wind model is used which takes into account the effects of radiative and inward conductive losses in the low corona and the chromospheric-coronal transition region. The results show that the total nonradiative energy input in magnetically open coronal regions is 5 + or - 10 to the 5th ergs/sq cm, and that most of the energy heating the coronal plasma is dissipated within 2 solar radii of the solar surface.

Withbroe, George L.↗
NASA NTRS2022

Evaluating Twenty-Year Trends in Earth’s Energy Flows from Observations and Reanalyses

Satellite, reanalysis, and ocean in situ data are analyzed to evaluate regional, hemispheric and global mean trends in Earth’s energy fluxes during the first twenty years of the 21st century. Regional trends in net top-of-atmosphere (TOA) radiation from the Clouds and the Earth’s Radiant Energy System (CERES), ECMWF Reanalysis 5 (ERA5), and a model similar to ERA5 with prescribed sea surface temperature (SST) and sea ice differ markedly, particularly over the Eastern Pacific Ocean, where CERES observes large positive trends. Hemispheric and global mean net TOA flux trends for the two reanalyses are smaller than CERES, and their climatological means are half those of CERES in the southern hemisphere (SH) and more than nine times larger in the northern hemisphere (NH). The regional trend pattern of the divergence of total atmospheric energy transport (TEDIV) over ocean determined using ERA5 analyzed fields is similar to that inferred from the difference between TOA and surface fluxes from ERA5 short-term forecasts. There is also agreement in the trend pattern over ocean for surface fluxes inferred as a residual between CERES net TOA flux and ERA5 analysis TEDIV and surface fluxes obtained directly from ERA5 forecasts. Robust trends are observed over the Gulf Stream associated with enhanced surface-to-atmosphere transfer of heat. Within the ocean, larger trends in ocean heating rate are found in the NH than the SH after 2005, but the magnitude of the trend varies greatly among datasets.

Norman G Loeb↗
DOE OSTI2021

Energy-Flow-Environment Linkage Map

Understanding how flexibility in environmental requirements can facilitate co-optimization of hydropower production outcomes and environmental outcomes is critical for future grid decision-making and operations as renewable energy resources increase. The environmental and power system outcomes connectivity linkage maps presented here provide a framework for conceptually and quantitatively linking power system outcomes to environmental outcomes through hydropower flow decisions. The Executive Summary Map serves as a starting for exploring the links between hydropower system performance outcomes and environmental outcomes. The centralized topic is “Flow from Hydropower System,” and connects the hydropower operations through “Flow through turbines” and “Non-turbine flows”, and to environmental outcomes through Reservoir elevation” and “Flow downstream of the hydropower system”. To the left of these central topics, “Hydro-mechanical operations” are linked through “Hydro-electrical operations” to “Hydropower performance outcomes” (“Reliability”, “Resilience”, “Revenue”, “Emissions”). On the right, environmental outcomes are grouped together by their physical location: “Upstream Outcomes” (“Upstream geomorphology”, “Upstream recreation”, “Upstream habitat”, “Upstream biota and biodiversity”, “Upstream water quality and greenhouse gas”), Outcomes relevant to both “Upstream/downstream or dam interface” (“Navigation”, “Dam safety and maintenance", “Human health”, “Water supply”, “Flood control”, ”Fish passage”), and “Downstream outcomes“ (e.g., “Downstream geomorphology”, “Downstream recreations”, “Downstream habitat”, “Downstream biota and biodiversity”, “Downstream water quality and greenhouse gas”). Each of these subtopics (e.g., “Hydro-mechanical operations”, “Hydro-electrical operations”, “Upstream geomorphology”, “Upstream recreation”) is further explored through their corresponding submaps. The “Read Me” file provides more detail information on map navigation. The “Models and tools database” file provides detailed information of models and tools presented in the maps.

13 HYDRO ENERGY↗
NASA NTRS1983

Nonlinear energy flow in a beam-plasma system

The three-dimensional character of the beam-plasma instability is investigated. The true beam-electron distribution function is resolved with a novel directional energy analyzer. The electron plasma waves are observed to develop a large spread in perpendicular wave numbers and damp in a relatively short distance producing an energetic electron tail on the background distribution. The damping is believed to be due to strong ion fluctuations which produce an anomalous resistivity.

Whelan, D. A.↗