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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Composite methods for hyperbolic equations

A composite approximation procedure combining the properties of the Lax-Wendroff and leapfrog algorithms is proposed for solving hyperbolic equations. For a one-dimensional equation, a three-step approximation consisting of a two-step Richtmeyer method followed by a leapfrog step is considered. This is a two-level scheme, so all difficulties, including storage requirements, associated with the three-level leapfrog are eliminated. For two-dimensional problems a generalization of the preceding method is used consisting of a rotated Richtmeyer method followed by a modified leapfrog step. It is found that the composite schemes are effective in reducing oscillations and nonlinear instabilities that affect the leapfrog method. The dissipation in the composite schemes is much less than in the Richtmeyer algorithm, and hence can be used for long term integrations.

Turkel, E.↗
NASA NTRS1977

Photoelectrolysis of water at high current density - Use of ultraviolet laser excitation

The behavior of TiO2 and SrTiO3 photoanodes in cells for the photoelectrolysis of H2O has been investigated for high-intensity 351-,364-nm excitation from an Ar ion laser. Intensities up to 380 W/sq cm have been used. For TiO2 a small amount of surface decomposition is found after irradiation at high intensity, whereas SrTiO3 undergoes no detectable changes. Current-voltage properties for both electrodes are essentially independent of light intensity up to the level of 380 W/sq cm, and there is little if any change in quantum efficiency for electron flow. Photocurrent densities have been shown to exceed 5 A/sq cm for O2 evolution. Data show that the energy storage rate associated with the SrTiO3 photoelectrolysis can exceed 30 W/sq cm; this represents the highest demonstrated rate of sustained optical-to-chemical energy conversion.

Bocarsly, A. B.↗
NASA NTRS1981

Predictability in a solvable stochastic climate model

A highly idealized atmospheric model is presented for the purpose of examining the limits of predictability for the large scales of the temperature field. The model is of the semiempirical type introduced by Budyko (1968, 1969) and Sellers (1969), but forced by a white noise heating term. The advantage of the considered model is its simplicity and the fact that analytical methods can be used throughout so that each assumption and simplification can be examined explicitly. On the other hand, the model lacks many features expected to be important in the real geophysical system. The predictability problem is illustrated by considering first a simple model for the global temperature. The characteristic time for the decay of a global temperature anomaly is determined by the ratio of the associated heat storage to the radiative loss rate.

North, G. R.↗
NASA NTRS1984

A strongly implicit procedure for the compressible Navier-Stokes equations

The strongly implicit procedure of Stone is used to obtain numerical solutions of the compressible Navier-Stokes equations in conservative form. In contrast to the spatially split Douglas-Gunn type methods, the method is shown to be numerically stable for the three-dimensional wave equation. The method is applied to a variety of external and internal two-dimensional flow problems involving shock wave boundary-layer interaction for both laminar and turbulent flows. The results are in good agreement with other methods and/or experiments. The storage penalty associated with the method is discussed and a simple, yet effective, means of minimizing the problem is presented.

Walters, R. W.↗
NASA NTRS1989

A test of a modified algorithm for computing spherical harmonic coefficients using an FFT

The Dilts (1985) algorithm for computing the spherical harmonic expansion coefficients for a function on a sphere, on the basis of a two-dimensional FFT, is presently modified, tested, and found to eliminate problems of overflow and large storage requirements associated with the encounter of harmonic degree values greater than 16. Results from timing tests show the Dilts program to be impractical, however, for the computation of spherical harmonic expansion coefficients for large harmonic degree values.

Elowitz, Mark↗
NASA NTRS1991

Collecting address traces from parallel computers

Trace driven simulation is a well-established method of performance analysis for single processor computer systems. However, efficient and accurate memory address tracing for parallel computer systems is not well understood. In this paper we present a critical survey of recently implemented approaches to address tracing and highlight the issues specific to collection of traces for both shared and distributed memory parallel computers. These issues include potential distortion of the relative ordering of events by the address tracing activity, realistic interleaving of addresses generated by multiple processors, and I/O and storage problems associated with collecting traces for large parallel systems. The strengths and weaknesses of the parallel tracing approaches are described.

Stunkel, Craig B.↗
NASA NTRS2011

Global Assimilation of Multi-Sensor Snow Observations for Improved Characterization of Snow Processes

Snow conditions on the land surface are recognized to be key components of the global hydrological cycle as they play a critical role in the determination of local and regional climate. In many mid-latitude and high-latitude regions, the seasonal water storage and associated spring snowmelt dominate the local hydrology. The contribution to the runoff and moisture conditions from snow is vital in supporting agriculture and in determining water resources management practices. Consequently, accurate characterization of snow properties becomes important for both end-use applications and weather and climate research. Recently a joint effort between the u.S. Air Force and NASA has enabled a blended, multi-sensor snow product known as the AFWA NASA Snow Algorithm (ANSA). This global snow dataset has been generated by utilizing the Earth Observation System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E) datasets. ANSA product includes estimates of snow cover extent, snow water equivalent (SWE) and SWE-derived snow depth fields. The MODIS-based products enable snow cover mappings under cloud-free conditions whereas the passive microwave data from AMSR-E provides measurements under cloudy conditions. These remotely-sensed snow observations are further augmented with the information from ground-based snow measurements through data fusion techniques. The resulting ANSA products are employed in the NASA Land Information System (LIS) data assimilation framework, which provides a comprehensive environment for integrating community land surface models, ground and satellite-based observations, and ensemble-based data assimilation tools. LIS incorporates the multisensor ANSA snow retrievals with the land surface model estimates to generate spatially and temporally continuous estimates of snow states, through data assimilation. A suite of experiments to assimilate ANSA snow cover, SWE and snow depth estimates with different land surface models in LIS are conducted and the resulting estimates of snow conditions are evaluated against a number of in-situ observational datasets, over several regions of the world. These evaluations are used to compare and contrast the advantages and disadvantages of these multi-sensor snow observations.

Kumar, Sujay↗
NASA NTRS2016

Mars Surface Systems Common Capabilities and Challenges for Human Missions

This paper describes the current status of common systems and operations as they are applied to actual locations on Mars that are representative of Exploration Zones (EZ) - NASA's term for candidate locations where humans could land, live and work on the Martian surface. Given NASA's current concepts for human missions to Mars, an EZ is a collection of Regions of Interest (ROIs) located within approximately 100 kilometers of a centralized landing site. ROIs are areas that are relevant for scientific investigation and/or development/maturation of capabilities and resources necessary for a sustainable human presence. An EZ also contains a habitation site that will be used by multiple human crews during missions to explore and utilize the ROIs within the EZ. The Evolvable Mars Campaign (EMC), a description of NASA's current approach to these human Mars missions, assumes that a single EZ will be identified within which NASA will establish a substantial and durable surface infrastructure that will be used by multiple human crews. The process of identifying and eventually selecting this single EZ will likely take many years to finalized. Because of this extended EZ selection process it becomes important to evaluate the current suite of surface systems and operations being evaluated for the EMC as they are likely to perform at a variety of proposed EZ locations and for the types of operations - both scientific and development - that are proposed for these candidate EZs. It is also important to evaluate proposed EZs for their suitability to be explored or developed given the range of capabilities and constraints for the types of surface systems and operations being considered within the EMC. Four locations identified in the Mars Exploration Program Analysis Group (MEPAG)'s Human Exploration of Mars Science Analysis Group (HEM-SAG) report are used in this paper as representative of candidate EZs that will emerge from the selection process that NASA has initiated. A field station site plan is developed for each of these four HEM-SAG sites. Because of the difficulty in getting equipment and supplies to the surface of Mars, specific assessments have been conducted to identify those systems and processes that can perform in multiple, sometimes completely unrelated, situations. Examples of common systems that are assessed at all of these sites include: (a) habitation and associated logistics storage systems, (b) a centralized power plant capable of supplying power to a geographically distributed (but within the central habitation zone) set of systems, (c) mobility systems that can be used to off-load and move payloads to specific locations at the central field station location that could also be used to traverse long distances to reach some of the more remote ROIs and (d) robotic systems that can support various activities (such as system set up and maintenance) at the field station that could also be used to explore scientific ROIs and used to support site-specific ISRU (In Situ Resource Utilization) production activities.

Toups, Larry↗
DOE OSTI2022

Geological characterization and ROZ potential of the Tar Springs Sandstone

This report focuses on regional and field scale geological characterization of the Tar Springs in Illinois using well records, including drilling and completion reports, well logs, and core data (core descriptions/core analyses) to analyze and interpret geological variations. In addition, oil saturation indicators (oil shows, oil saturation from core analysis, and drill stem test data) were analyzed to determine the ROZ potential of the Tar Springs Sandstone

02 PETROLEUM↗
DOE OSTI2022

Analyses of the C. Winter #10 Enhanced Open-hole Drill Stem Test of the Residual Oil Zone in the Cypress Sandstone

The objective of this report is to detail enhanced open-hole drill stem test (DST) of the Residual Oil Zone in the Cypress Sandstone. DST are 1) to confirm there is no mobile oil from the suspected residual oil zone (ROZ), 2) estimate vertical and horizontal permeability in the ROZ, and 3) test vertical communication between the Cypress main pay zone (MPZ) and the ROZ, across the upper calcite layer.

02 PETROLEUM↗
DOE OSTI2023

Modeling-Based Assessment of Deep Seismic Potential Induced by Geologic Carbon Storage

Induced seismicity is an inherent risk associated with geologic carbon storage (GCS) in deep rock formations that could contain undetected faults prone to failure. Modeling-based risk assessment has been implemented to quantify the potential of injection-induced seismicity, but typically simplified multiscale geologic features or neglected multiphysics coupled mechanisms because of the uncertainty in field data and computational cost of field-scale simulations, which may limit the reliable prediction of seismic hazard caused by industrial-scale CO 2 storage. The degree of lateral continuity of the stratigraphic interbedding below the reservoir and depth-dependent fault permeability can enhance or inhibit pore-pressure diffusion and corresponding poroelastic stressing along a basement fault. In conclusion, this study presents a rigorous modeling scheme with optimal geological and operational parameters needed to be considered in seismic monitoring and mitigation strategies for safe GCS.

58 GEOSCIENCES↗
NASA NTRS1977

Continuous data stream FIFO magnetic bubble domain shift register

There is described a simple first-in, first out (FIFO) magnetic bubble domain shift register which has continuous data storage capability. In a preferred embodiment, two parallel detector branches are associated with a main storage loop. The bubbles in the storage loop are replicated toward each detector branch by passive replicators in the storage loop. Annihilators associated with each of the replicators and each of the detectors are arranged an appropriate distance from the replicators so that selective energization of the annihilators permits certain bits to propagate to one detector and other bits to propagate to the other detector. Connection of the detectors in an appropriate bridge circuit permits full data rate reclamation.

Chen, Thomas T.↗
DOE OSTI2025

Potential Risks Associated with Short-Term Hydrogen Storage in Methane Reservoirs

Hydrogen (H2) has been identified as a flexible energy carrier with zero emissions. It is possible to utilize H2 by storing Hyblend, or H2 blended with CH4, in existing natural gas infrastructure. However, the compatibility of adapting the current CH4 storage strategies to include H2 injection has not been fully demonstrated. It is essential that we understand the impact of H2 gas on the naturally occurring microbial community of subsurface storage reservoirs before deploying large-scale H2-CH4 storage. We designed a series of experiments that allowed us to identify potential challenges of HyBlend Storage in existing methane reservoirs (Figure 1). First, we characterized two field fluid samples from a methane reservoir located in Western United States. Next, we used these samples to complete a series of short-term reactor experiments at reservoir conditions for a natural gas (100% CH4) and HyBlend (80% CH4/20% H2) storage environment.

geomicrobiology↗
NASA NTRS1977

Mechanical energy storage device for hip disarticulation

An artificial leg including a trunk socket, a thigh section hingedly coupled to the trunk socket, a leg section hingedly coupled to the thigh section and a foot section hingedly coupled to the leg section is outlined. A mechanical energy storage device is operatively associated with the artificial leg for storage and release of energy during the normal walking stride of the user. Energy is stored in the mechanical energy storage device during a weight-bearing phase of the walking stride when the user's weight is on the artificial leg. Energy is released during a phase of the normal walking stride, when the user's weight is removed from the artificial leg. The stored energy is released from the energy storage device to pivot the thigh section forwardly about the hinged coupling to the trunk socket.

Vallotton, W. C.↗
DOE OSTI2023

Tidal energy extraction modifies tidal asymmetry and transport in a shallow, well-mixed estuary

Tidal energy extraction is increasingly being studied as a potential renewable energy resource in estuaries worldwide. Although it is understood that energy extraction via tidal stream turbines can modify currents and transport within estuaries, it is not clear how the underlying nonlinear physical mechanisms dictating tidal hydrodynamics are modulated. This research investigates the influence of a hypothetical tidal stream turbine array on barotropic tidal processes in a shallow, well-mixed system: the Piscataqua River – Great Bay (PRGB) estuary, using a numerical model. The modeled turbine farm includes 180 turbines which would extract an estimated 44.7 GWh of energy, annually. The tidal hydrodynamic model for the existing condition is validated with in-situ observations of currents and water level before analyzing tidal asymmetry and transport with and without tidal turbines. Results indicate that the tidal turbine array will decrease tidal elevation and current magnitudes system-wide, but generally reduce ebb currents and transport more than flood over most of the estuary footprint, thereby diminishing tidal asymmetry. The smaller asymmetric distortion compared to the no-turbine case is attributed to reductions in the storage volume of water over the estuary’s extensive tidal flat regions between low and high waters which decreases the associated nonlinear intertidal storage mechanism up to 25%. This leads to weakened ebb dominance over estuary sections from the mouth to mid-reaches, where depths are deep enough to keep the combined nonlinear shallow water and frictional effects from asserting control over the storage mechanism. Even in upstream shallow regions where depth-dependent friction controls asymmetry in both cases, the frictional mechanism is reduced only by 10% with turbines. Some environmental considerations of this work are discussed, with focus on sediment transport, water quality, and ecology.

16 TIDAL AND WAVE POWER↗
NASA NTRS1980

Heat storage in alloy transformations

The theory of eutectic transformation was examined to find guidelines to the best material combinations to examine. The heats of transformation were measured calorimetrically, and the volume changes of expanding solid mixtures and homogeneous liquid solutions, especially during the transformation between the two states at fixed temperature, were measured by changes in X-ray absorption. Heat flow models appropriate to storage in phase change materials were developed along with efficient calculating procedures so that the relative importance of the problems associated with energy storage density, heat conduction, and similar properties could be assessed.

Birchenall, C. E.↗
DOE OSTI2024

CO2 Saline Storage Talk at the University of Wyoming

These are slides presented virtually to a class on Carbon Capture and Storage (CCS) at the University of Wyoming in Laramie WY. The talk was on the basics of carbon storage in saline formations and reviewed basic geology, important physical properties of CO2 and brine, how fluids flow in the subsurface, environmental risks associated with CO2 storage, the regulations governing CO2 saline storage, and high-level design considerations. The FECM/NETL CO2 Saline Storage Cost Model was used to illustrate how geologic properties vary in different regions of the US (PA, IL and WY) and how the performance of CO2 storage and the cost of CO2 CO2 saline storage depends on geology (October 23, 2024).

Morgan, David↗
DOE OSTI2024

Report series: finding of effect and mitigation documentation for the mercury solar photovoltaic array and battery energy storage system, area 23, nevada national security site, nye county, nevada

The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) proposes to install solar photovoltaic (PV) power generation arrays and an associated battery energy storage system (BESS) for the town of Mercury at the Nevada National Security Site (NNSS) in Nye County, Nevada (Figure 1). The purposes of the development of this facility are to support long-term efforts to modernize Mercury and to provide energy-resilient infrastructure and address climate adaptation needs. Because it is within the boundary of the Mercury Historic District (MHD), it is subject to the terms of the Programmatic Agreement Between the National Nuclear Security Administration Nevada Field Office and the Nevada State Historic Preservation Officer Regarding Modernization and Operational Maintenance of the Nevada National Security Site, at Mercury in Nye County, Nevada (hereafter referred to as the Mercury PA). An identification and evaluation report prepared for this undertaking determined that a contributing element to the MHD, the Mercury airstrip (26NY15777), is within the APE (Haynes 2024). The Mercury airstrip was developed following the closure of Camp Desert Rock in 1957 and used until late 1963 or 1964 when the Camp Desert Rock Airport was renovated, and the Mercury Bypass road constructed. The town of Mercury and the immediate surrounding area have been determined eligible for listing in the National Register of Historic Places (NRHP) as the MHD (SHPO Resource No. D230) under Criteria A and C for its importance in supporting nuclear testing and scientific research from 1951 through 1992 (Reed 2019). Originally recorded in 2016, 26NY15777 was determined individually not eligible for listing in the NRHP because it lacked sufficient integrity to convey its significance (Palmer 2016). It was subsequently determined in 2018 to be a contributing element of the MHD in an architectural survey of the district (Palmer 2018) and identified in Appendix C of the Mercury PA as a Category I contributing element. However, as per Stipulation IV.B.2, because the airstrip had already been formally evaluated and determined not to be individually eligible for the NRHP in consultation with the SHPO, this categorization was an error. NNSA/NFO reported this to the SHPO in Haynes 2024 and the SHPO concurred on June 11, 2024 (Reed). Accordingly, the airstrip is a Category II Property for the purposes of complying with the Mercury PA. The Mercury airstrip is a historic property for the purposes of compliance with Section 106 of the National Historic Preservation Act (NHPA) and subject to the stipulations of the Mercury PA.

25 ENERGY STORAGE↗