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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 793 records · Page 44

PeleC: An adaptive mesh refinement solver for compressible reacting flows

Reacting flow simulations for combustion applications require extensive computing capabilities. Leveraging the AMReX library, the Pele suite of combustion simulation tools targets the largest supercomputers available and future exascale machines. We introduce PeleC, the compressible solver in the Pele suite, and detail its capabilities, including complex geometry representation, chemistry integration, and discretization. We present a comparison of development efforts using both OpenACC and AMReX’s C++ performance portability framework for execution on multiple GPU architectures. We discuss relevant details that have allowed PeleC to achieve high performance and scalability. PeleC’s performance characteristics are measured through relevant simulations on multiple supercomputers. The success of PeleC’s design for exascale is exhibited through demonstration of a 160 billion cell simulation and weak scaling onto 100% of Summit, an NVIDIA-based GPU supercomputer at Oak Ridge National Laboratory. Our results provide confidence that PeleC will enable future combustion science simulations with unprecedented fidelity.

97 MATHEMATICS AND COMPUTING↗

Preserving Superconvergence of Spectral Elements for Curved Domains via h and p-Geometric Refinement [Slides]

Spectral element methods (SEM) are extensions of finite element methods (FEM) that employ Gauss-Lobatto or similar nodes instead of equidistant nodes for high-order elements. SEM can deliver superior accuracy compared to equidistant FEM due to potential superconvergence. However, significant challenges remain for domains with curved boundaries, which have limited the advantages of SEM for real-world applications. In this work, we propose a novel approach to bolster the overall accuracy and preserve the superconvergence of SEM over curved domains.

97 MATHEMATICS AND COMPUTING↗

Using Complementary Methods of Synchrotron Radiation Powder Diffraction and Pair Distribution Function to Refine Crystal Structures with High Quality Parameters—A Review

Determination of the atomic-scale structures of certain fine-grained minerals using single-crystal X-ray diffraction (XRD) has been challenging because they commonly occur as submicron and nanocrystals in the geological environment. Synchrotron powder diffraction and scattering techniques are useful complementary methods for studying this type of minerals. In this review, we discussed three example studies investigated by combined methods of synchrotron radiation XRD and pair distribution function (PDF) techniques: (1) low-temperature cristobalite; (2) kaolinite; and (3) vernadite. Powder XRD is useful to determine the average structure including unit-cell parameters, fractional atomic coordinates, occupancies and isotropic atomic displacement parameters. X-ray/Neutron PDF methods are sensitive to study the local structure with anisotropic atomic displacement parameters (ADP). The results and case studies suggest that the crystal structure and high-quality ADP values can be obtained using the combined methods. The method can be useful to characterize crystals and minerals that are not suitable for single-crystal XRD.

58 GEOSCIENCES↗

Low-thrust orbit transfer optimization with refined Q-law and multi-objective genetic algorithm

An optimization method for low-thrust orbit transfers around a central body is developed using the Q-law and a multi-objective genetic algorithm. in the hybrid method, the Q-law generates candidate orbit transfers, and the multi-objective genetic algorithm optimizes the Q-law control parameters in order to simultaneously minimize both the consumed propellant mass and flight time of the orbit tranfer. This paper addresses the problem of finding optimal orbit transfers for low-thrust spacecraft.

low-thrust orbit transfer↗

Manufacturing Energy and Carbon Footprint: Petroleum Refining (NAICS 31 - 33) (revised March 2012 from MECS 2006)

Manufacturing energy and carbon footprints map energy consumption and losses, as well as greenhouse gas emissions from fuel consumption, for fifteen individual U.S. manufacturing sectors (representing 94% of all manufacturing energy use) andfor the entire manufacturing sector. By providing energy consumption and emissions figures broken down by end use, the footprints allow for comparisons of energy use and emissions sources both within and across sectors.The footprints portray a large amount of information for each sector, including: * Comparison of the energy generated offsite and transferred to facilities versus that generated onsite* Nature and amount of energy consumed by end use within facilities * Magnitude of the energy lost both outside and inside facility boundaries* Magnitude of the greenhouse gas emissions released as a result of manufacturing energy use. Energy losses indicate opportunities to improve efficiency by implementing energy management best practices, upgrading energysystems, and developing new technologies. Footprints are available below for each sector. Data is presented in two levels of detail. The first page provides a high-level snapshot of the offsite and onsite energy flow, and the second page shows the detail for onsite generation and end use of energy. The principle energy use data source is the U.S. Department of Energy (DOE) Energy Information Administration's(EIA's) Manufacturing Energy Consumption Survey (MECS), for consumption in the year 2006, when the survey was last completed.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Petroleum Refining Footprint, October 2012 (MECS 2006)

Manufacturing energy and carbon footprints map energy consumption and losses, as well as greenhouse gas emissions from fuel consumption, for fifteen individual U.S. manufacturing sectors (representing 94% of all manufacturing energy use) and for the entire manufacturing sector. By providing energy consumption and emissions figures broken down by end use, the footprints allow for comparisons of energy use and emissions sources both within and across sectors. The footprints portray a large amount of information for each sector, including: * Comparison of the energy generated offsite and transferred to facilities versus that generated onsite * Nature and amount of energy consumed by end use within facilities * Magnitude of the energy lost both outside and inside facility boundaries * Magnitude of the greenhouse gas emissions released as a result of manufacturing energy use. Energy losses indicate opportunities to improve efficiency by implementing energy management best practices, upgrading energy systems, and developing new technologies. Footprints are available below for each sector. Data is presented in two levels of detail. The first page provides a high- level snapshot of the offsite and onsite energy flow, and the second page shows the detail for onsite generation and end use of energy. The principle energy use data source is the U.S. Department of Energy (DOE) Energy Information Administration's (EIA's) Manufacturing Energy Consumption Survey (MECS), for consumption in the year 2006, when the survey was last completed.

Manufacturing Energy and Carbon Footprint, footpri↗

Traveling Molten Zone Refining Process Development for Innovative Fuel Cycle Solutions

Considering the phase diagrams of metallic spent fuel constituents, the melting and solidifying of spent metallic fuel causes three immiscible layers (actinide-rich, lanthanide-rich, and Group II-rich) and the condensate phase (Group I) to form. We believe this anticipated immiscibility offers an untapped opportunity for innovative fuel cycle solutions. Through the proposed project, we anticipate confirming the expected phase behavior and develop a thermal treatment process to rapidly extract actinides from spent metallic fuels. The prime apparatus for both purposes is a traveling molten zone system with induction heating. We envision that one rapid pass of the molten zone from the bottom to the top of the metallic rod incorporating species of spent metallic fuels should produce the expected immiscible layer formation and provide species partitioning data effectively and cleanly. It will also demonstrate an actinide extraction process by concentrating the impurities at the top segment of the rod and leaving the actinide species behind as the bulk rod. The successful execution of the project will demonstrate proof of concept for a transformative process path for used metal fuels in terms of economics and safeguards.

36 MATERIALS SCIENCE↗

Refining Groundwater Monitoring Approaches Through an Objectives-Driven Process - 16333

Groundwater monitoring is conducted throughout the groundwater remediation process, from initial site characterization through demonstration of cleanup objectives attainment. The DOE uses the groundwater monitoring data to define plumes, manage ongoing remediation, and determine how close the contamination levels are to meeting an endpoint criteria, such as a drinking water standard. Due to the expense of groundwater sampling and analysis, the DOE Office of Environmental Management compiled a synopsis of monitoring technologies and approaches, and defined opportunities for improving environmental remediation monitoring. This information included techniques to optimize and streamline groundwater monitoring. At the Hanford Site, years of extensive groundwater monitoring have been applied to support characterization and remedy-selection activities. Continuation of this monitoring intensity would be costly and would need to be reviewed in the context of future activities for groundwater remedy implementation. A structured review of monitoring plans is underway and has identified significant potential changes to the monitoring approach. These changes have been developed based on careful definition of monitoring objectives and consideration of innovative and targeted techniques to gather the appropriate data for remedy performance monitoring and transition to longer-term monitoring and closure. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗