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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 289 records · Page 16

Development of Doppler Global Velocimetry as a Flow Diagnostics Tool

The development of Doppler global velocimetry is described from its inception to its use as a flow diagnostics tool. Its evolution is traced from an elementary one-component laboratory prototype, to a full three-component configuration operating in a wind tunnel at focal distances exceeding 15 m. As part of the developmental process, several wind tunnel flow field investigations were conducted. These included supersonic flow measurements about an oblique shock, subsonic and supersonic measurements of the vortex flow above a delta wing, and three-component measurements of a high-speed jet.

Meyers, James F.↗

Dramatic Change in Jupiter's Great Red Spot from Spacecraft Observations

Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here we show that this change has been accompanied by an increase in cloud/haze reflectance as sensed in methane gas absorption bands, increased absorption at wavelengths shorter than 500 nanometers, and increased spectral slope between 500 and 630 nanometers. These changes occurred between 2012 and 2014, without a significant change in internal tangential wind speeds; the decreased size results in a 3.2 day horizontal cloud circulation period, shorter than previously observed. As the GRS has narrowed in latitude, it interacts less with the jets flanking its north and south edges, perhaps allowing for less cloud mixing and longer UV irradiation of cloud and aerosol particles. Given its long life and observational record, we expect that future modeling of the GRS's changes, in concert with laboratory flow experiments, will drive our understanding of vortex evolution and stability in a confined flow field crucial for comparison with other planetary atmospheres.

planets and satellites: atmospheres aEuro" planets↗

Prebiotic Chemistry of Pluto

We present the case for the presence of complex organic molecules, such as amino acids and nucleobases, formed by abiotic processes on the surface and in near-subsurface regions of Pluto. Pluto's surface is tinted with a range of non-ice substances with colors ranging from light yellow to red to dark brown; the colors match those of laboratory organic residues called tholins. Tholins are broadly characterized as complex, macromolecular organic solids consisting of a network of aromatic structures connected by aliphatic bridging units (e.g., Imanaka et al.,2004; Materese et al.,2014, 2015). The synthesis of tholins in planetary atmospheres and in surface ices has been explored in numerous laboratory experiments, and both gas- and solid-phase varieties are found on Pluto. A third variety of tholins, exposed at a site of tectonic surface fracturing called Virgil Fossae, appears to have come from a reservoir in the subsurface. Eruptions of tholin-laden liquid H2O from a subsurface aqueous repository appear to have covered portions of Virgil Fossae and its surroundings with a uniquely colored deposit (D.P. Cruikshank, personal communication) that is geographically correlated with an exposure of H2O ice that includes spectroscopically detected NH3 (C.M. Dalle Ore, personal communication). The subsurface organic material could have been derived from presolar or solar nebula processes, or might have formed in situ. Photolysis and radiolysis of a mixture of ices relevant to Pluto's surface composition (N2, CH4, CO) have produced strongly colored, complex organics with a significant aromatic content having a high degree of nitrogen substitution similar to the aromatic heterocycles pyrimidine and purine (Materese et al.,2014, 2015; Cruikshank et al.,2016). Experiments with pyrimidines and purines frozen in H2O-NH3 ice resulted in the formation of numerous nucleobases, including the biologically relevant guanine, cytosine, adenine, uracil, and thymine (Materese et al.,2017). The red material associated with the H2O ice may contain nucleobases resulting from energetic processing on Pluto's surface or in the interior. Some other Kuiper Belt objects also exhibit red colors similar to those found on Pluto and may therefore carry similar inventories of complex organic materials. The widespread and ubiquitous nature of similarly complex organic materials observed in a variety of astronomical settings drives the need for additional laboratory and modeling efforts to explain the origin and evolution of organic molecules. Pluto observations reveal complex organics on a small body that remains close to its place of origin in the outermost regions of the Solar System.

Cruikshank, D. P.↗

Automation of FARM from Alpha Phase to Beta Phase

Integrated energy systems (IES) combine different energy technologies in synergistic ways to achieve a more secure and economical energy supply. The RAVEN-based HYBRID framework and the RAVEN plugin for grid and capacity optimization (HERON) are used to find the optimal installed capacity and the optimal economical dispatch of each component of the IES, by respecting the limits on the production variables and the corresponding rates of variation (explicit constraints). Besides, there are other process variables whose evolution needs to be bounded to avoid damaging the components (e.g., condensers, heat exchangers, steam generators, etc.) or degrading the process efficiency (e.g., electrolysis in the hydrogen production process). To avoid violating these latter limits (implicit constraints), a proof-of-concept HERON validator based on Feasible Actuator Range Modifier (FARM-Alpha) was developed by Argonne National Laboratory in January 2021. This FARM-Alpha validator calculates the evolution of process variables on whom the implicit constraints are placed, and then provides feedback to HERON dispatcher to adjust the power setpoints of three IES components, i.e., Balance of Plant, Secondary Energy Source, and Thermal Energy Storage, so as to meet both the explicit and implicit constraints. FARM-Alpha was designed to assess the performance of FARM as a HERON validator only, i.e., the list of components and implicit operational constraints were hard-coded within the source code. The lack of flexibility of the corresponding software structure does not allow the deployment in production environment. This report describes the development and the implementation of an enhanced version of the FARM-based validator (FARM-Beta), which ensures more flexibility for the end user in modeling multiple IES configurations and scenarios. Several test cases of the power dispatch problem were then selected to demonstrate the capabilities offered by FARM-beta. The test cases illustrate the efficiency of the closed-loop optimization scheme and the capability to calculate set-point trajectories satisfying both explicit and implicit constraints.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Examination of the physical, electrical, and microwave evolution of sea water into young ice

Knowledge of the relationships between ice thickness, its temperature profile, the distribution of salinity, the dielectric property profile, and roughness of the air-ice interface is important to the understanding of the backscatter response of new and young sea ice. Backscatter, physical property, and electrical property measurements made in the laboratory during the first 120 h of growth aid in describing the evolution of first-year ice, in this case open water to gray ice (14.5 cm thick). Results on the evolution response for the case when the ambient air temperature is about -15 C are given, providing insight into the effects of upper ice sheet temperatures, the accompanying dielectric constant response, and the collection of brine and free water at the air-ice interface on the backscatter response.

Onstott, Robert G.↗

Hardening Doppler Global Velocimetry Systems for Large Wind Tunnel Applications

The development of Doppler Global Velocimetry from a laboratory curiosity to a wind tunnel instrumentation system is discussed. This development includes system advancements from a single velocity component to simultaneous three components, and from a steady state to instantaneous measurement. Improvements to system control and stability are discussed along with solutions to real world problems encountered in the wind tunnel. This on-going development program follows the cyclic evolution of understanding the physics of the technology, development of solutions, laboratory and wind tunnel testing, and reevaluation of the physics based on the test results.

Meyers, James F.↗

Temperature Effect of Gas Bubble Evolution in UCN Fuel Kernels Irradiated by Swift Xe Ions

UC1-xNx fuel kernels provided by Oak Ridge National Laboratory (ORNL) were irradiated by 84 MeV Xe ions at two different temperatures (450°C & 750°C) at the Argonne Tandem Linac Accelerator System (ATLAS) at Argonne National Laboratory, followed by post-irradiation examination. The primary goal of this study was to understand gas bubble formation (due to accumulation of Xe gas) and corresponding size evolution dependent upon net Xe deposition at the two different temperatures. From the post-irradiation examinations of the samples, it can be concluded at 750°C, with same amount of dose received, the Xe gas bubbles seems to coarsen much more easily compared to 450°C. The results generated for fission gas bubble evolution observed in this study can be used to support fuel performance models for UC1-xNx fuel kernels.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Workshop summary. Biomedical and Space-Related Research with Heavy Ions at the BEVALAC

The authors provide an overview of papers presented at a workshop on Biomedical and Space-Related Research with Heavy Ions at the BEVALAC at Lawrence Berkeley Laboratory. Goals of the meeting were to determine the critical experiments using heavy ions as probes in radiation physics, radiation chemistry, macromolecular and cellular biology, evolution science, basic neurophysiology, and medical therapies; how beam lines and facilities at Lawrence Berkeley Laboratory can be improved for these experiments; and implications in priorities and funding for national policy. Workshop topics included physics and facilities, cellular and molecular biology, tissue radiobiology, and the future of heavy ion research.

NASA Discipline Radiation Health↗

S&TR July-August: Beyond Ignition

On December 5, 2022, Lawrence Livermore’s National Ignition Facility achieved the first-ever successful positive-gain ignition shot. This scientific advance, heralded worldwide, required a multidecadal effort to synthesize physics theory, laser technologies, computation and diagnostic capabilities, as well as engineering, materials development, and other inputs. The question, “Can ignition be achieved?” had been answered. Since then, the Laboratory has answered the question, “Can we do it again?” with additional ignition shots at increasing yield. Now Lawrence Livermore researchers ask, “Can we improve ignition outcomes?” for the benefit of the Stockpile Stewardship Program. Interrelated articles presenting the Laboratory’s ignition science, the role of supercomputing in achieving ignition, the evolution of diagnostic instruments to measure ignition data, and the ambitious steps required to realize a fusion energy future lead to one answer: “Yes, we can.”

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Sustainable Data Evolution Technology for Power Grid Optimization

The SDET Tool is used to create open-access power grid data sets and facilitate updates of these data sets by the community. Pacific Northwest National Laboratory (PNNL) and its power industry and software vendor partners are developing an innovative sustainable data evolution technology (SDET) to create open-access power grid datasets and facilitate updates to these datasets by the power grid community. The objective is to make this a sustained effort within and beyond the ARPA-E GRID DATA program so that the datasets can evolve over time and meet the current and future needs for power grid optimization and potentially other applications in power grid operation and planning.

Source record↗

Sustainable Data Evolution Technology for Power Grid Optimization

The SDET Tool is used to create open-access power grid data sets and facilitate updates of these data sets by the community. Pacific Northwest National Laboratory (PNNL) and its power industry and software vendor partners are developing an innovative sustainable data evolution technology (SDET) to create open-access power grid datasets and facilitate updates to these datasets by the power grid community. The objective is to make this a sustained effort within and beyond the ARPA-E GRID DATA program so that the datasets can evolve over time and meet the current and future needs for power grid optimization and potentially other applications in power grid operation and planning.

Source record↗

WVU’s contribution within the ZAPP collaboration on the Z Facility at Sandia National Laboratories: Final Technical Report

In Year 1, photoionized silicon spectroscopy experiments were designed and executed, with charge-state distribution and ionic column densities comparable to the circumsource environments of accretion-powered black holes. Charge-state distribution was measured with absorption spectroscopy, using the Z-pinch itself as backlight, and the photoionizing radiation flux was determined with x-ray power measurements, accounting appropriately for geometrical dilution. The emergent emission spectrum was measured with a high-sensitivity time-integrated spectrometer. The emission has been measured from plasmas with varying size to elucidate the radiation transport effects. Data and knowledge of the controlled experimental conditions were provided to collaborators who used different atomic kinetics spectral synthesis codes to predict the emission spectrum. In Years 2 and 3, multi-element (in layers) foil was used for diagnostic development. A framing mask was implemented into the configuration to aperture the radiation incident on the foil. The foil distance from the z-pinch was adjusted to achieve designed electron temperature and ultimately mounted directly on the Return-Current Cannister. A much higher ionization state was achieved, which is desirable for diagnostic development. In Year 4, significant data analysis took place. Astrophysics related projects were introduced "Seeking a full theory of Stark broadening at HED in the presence of crossed E and B fields for estimating surface gravity from line profiles in Magnetic White Dwarf (MWD) stars" and "Plasma collective effects in atomic kinetics calculations of lineshape, line position, and line amplitude" for inclusion into the ZAPP collaboration, but were declined by ZAPP leadership. During the grant period, WVU contributed to three proposals for a ZAPP Center of Excellence that were prepared and/or submitted in part or in full. (1) NSF Physics Frontier Center solicitation 16-561, PI / Director: A. Wootton, UTexas, "Center for experimental astrophysic"s (declined), (2) NSF Science and Technology Center solicitation 2017, PI/Director: D. Winget, UTexas, "Formation and Evolution of Planets, Stars and Galaxies and Extreme-Parameter Laboratory Astrophysics" (awaiting restoration of the solicitation after unexpected postponement), and (3) NNSA Stewardship Science Grant Program solicitation 81-112, PI/Director: D. Winget, UTexas, "Center for Astrophysical Plasma Properties" (submitted in 2017, awarded in 2018). Based on the work performed during the grant period, a new NNSA grant application to support a WVU project in ZAPP, "Spectroscopic methods to obtain electron density and electron temperature applied to soft x-ray absorption spectra from radiatively heated Z-pinch plasmas", was submitted in 2017 and funded in 2018.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

2017 GTO Project review Laboratory Evaluation of EGS Shear Stimulation.

The objectives and purpose of this research has been to produce laboratory-based experimental and numerical analyses to provide a physics-based understanding of shear stimulation phenomena (hydroshearing) and its evolution during stimulation. Water was flowed along fractures in hot and stressed fractured rock, to promote slip. The controlled laboratory experiments provide a high resolution/high quality data resource for evaluation of analysis methods developed by DOE to assess EGS “behavior” during this stimulation process. Segments of the experimental program will provide data sets for model input parameters, i.e., material properties, and other segments of the experimental program will represent small scale physical models of an EGS system, which may be modeled. The coupled lab/analysis project has been a study of the response of a fracture in hot, water-saturated fractured rock to shear stress experiencing fluid flow. Under this condition, the fracture experiences a combination of potential pore pressure changes and fracture surface cooling, resulting in slip along the fracture. The laboratory work provides a means to assess the role of “hydroshearing” on permeability enhancement in reservoir stimulation. Using the laboratory experiments and results to define boundary and input/output conditions of pore pressure, thermal stress, fracture shear deformation and fluid flow, and models were developed and simulations completed by the University of Oklahoma team. The analysis methods are ones used on field scale problems. The sophisticated numerical models developed contain parameters present in the field. The analysis results provide insight into the role of fracture slip on permeability enhancement-“hydroshear” is to be obtained. The work will provide valuable input data to evaluate stimulation models, thus helping design effective EGS.

58 GEOSCIENCES↗

The Evolution of Three Dimensional Visualization for Commanding the Mars Rovers

NASA's Jet Propulsion Laboratory has built and operated four rovers on the surface of Mars. Two and three dimensional visualization has been extensively employed to command both the mobility and robotic arm operations of these rovers. Stereo visualization has been an important component in this set of visualization techniques. This paper discusses the progression of the implementation and use of visualization techniques for in-situ operations of these robotic missions. Illustrative examples will be drawn from the results of using these techniques over more than ten years of surface operations on Mars.

stereo visualization↗

Science & Technology Review: Laser Program Celebrates 50 Years

At Lawrence Livermore National Laboratory, we focus on science and technology research to ensure our nation’s security. We also apply that expertise to solve other important national problems in energy, bioscience, and the environment. Science & Technology Review is published eight times a year to communicate, to a broad audience, the Laboratory’s scientific and technological accomplishments in fulfilling its primary missions. The publication’s goal is to help readers understand these accomplishments and appreciate their value to the individual citizen, the nation, and the world. Lawrence Livermore established its unified Laser Program, bringing together researchers from across the Laboratory to develop high-energy laser systems for pursuing inertial confinement fusion. As the article beginning on p. 4 describes, over the program’s 50 years, Livermore and collaborating institutions have been at the forefront of scientific and technological innovations, paving the way to a major fusion milestone in August 2021. The cover represents the evolution of the laser showing (back) an early tabletop system pictured with Laboratory physicists John Emmett (left) and John Nuckolls, and (front) an artist’s rendering of a fusion experiment inside the National Ignition Facility.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

On factors controlling precursor slip fronts in the laboratory and their relation to slow slip events in nature

Spatial variations in frictional properties on natural faults are believed to be a factor influencing the presence of slow slip events (SSEs). This effect was tested on a laboratory frictional interface between two polymethyl methacrylate (PMMA) bodies. We studied the evolution of slip and slip rates that varied systematically based on the application of both high and low normal stress (σ 0 =0.8 or 0.4 MPa) and the far-field loading rate (V LP ). A spontaneous, frictional rupture expanded from the central, weaker, and more compliant section of the fault that had fewer asperities. Slow rupture propagated at speeds V slow ~0.8 to 26 mm s -1 with slip rates from 0.01 to 0.2 μm s -1 , resulting in stress drops around 100 kPa. During certain nucleation sequences, the fault experienced a partial stress drop, referred to as precursor detachment fronts in tribology. Only at the higher level of normal stress did these fronts exist, and the slip and slip rates mimicked the moment and moment release rates during the 2013–2014 Boso SSE in Japan. The laboratory detachment fronts showed rupture propagation speeds V slow /V R ϵ (5 to 172) × 10 -7 and stress drops ~ 100 kPa, which both scaled to the aforementioned SSE. Distributions of asperities, measured using a pressure sensitive film, increased in complexity with additional normal stress—an increase in normal stress caused added complexity by increasing both the mean size and standard deviation of asperity distributions, and this appeared to control the presence of the detachment front.

58 GEOSCIENCES↗

Coupled Thermo–Hydro–Mechanical Modeling of Hydro-Shearing Stimulation in an Enhanced Geothermal System in the Raft River Geothermal Field, USA

The Raft River Enhanced Geothermal System (EGS) demonstration project aims to improve the geothermal production by enhancing the reservoir permeability via shear stimulation in well RRG-9. In this paper, we performed a series of 3D thermo– hydro–mechanical (THM) simulations to investigate the influence of hydraulic and thermal effects on the development of this EGS. The model includes synthetic fracture populations based on borehole televiewer images and in-situ stress measurements from well RRG-9. Fracture permeability evolution is determined using an empirical permeability law developed from laboratory experiments. The model was calibrated by comparing the hydraulic response to field observations, including wellhead pressure, injection rate, and well injectivity. Particularly, we analyzed the enhancement of reservoir permeability and the spatial extent of the stimulation zone for the given injection schedule. Our results indicate that the permeability enhancement of fractured geothermal reservoir is caused by the combined effects of injection-induced cooling and fluid pressure increase. The decrease of temperature plays a dominant role in reactivation of natural fractures under the hydro-shearing mechanism, while the higher injection pressure promotes shear failure and enlarges the stimulation zone. Finally, for the specified extensional stress state, the model favors greatest permeability enhancement along the maximum horizontal principal stress, a moderate vertical enhancement, and a smaller gain along the minimum horizontal principal stress.

58 GEOSCIENCES↗