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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 1,261 records · Page 70
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Implementation and Optimization of miniGMG - a Compact Geometric Multigrid Benchmark

Multigrid methods are widely used to accelerate the convergence of iterative solvers for linear systems used in a number of different application areas. In this report, we describe miniGMG, our compact geometric multigrid benchmark designed to proxy the multigrid solves found in AMR applications. We explore optimization techniques for geometric multigrid on existing and emerging multicore systems including the Opteron-based Cray XE6, Intel Sandy Bridge and Nehalem-based Infiniband clusters, as well as manycore-based architectures including NVIDIA's Fermi and Kepler GPUs and Intel's Knights Corner (KNC) co-processor. This report examines a variety of novel techniques including communication-aggregation, threaded wavefront-based DRAM communication-avoiding, dynamic threading decisions, SIMDization, and fusion of operators. We quantify performance through each phase of the V-cycle for both single-node and distributed-memory experiments and provide detailed analysis for each class of optimization. Results show our optimizations yield significant speedups across a variety of subdomain sizes while simultaneously demonstrating the potential of multi- and manycore processors to dramatically accelerate single-node performance. However, our analysis also indicates that improvements in networks and communication will be essential to reap the potential of manycore processors in large-scale multigrid calculations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Benchmark Measurements of the BeRP Ball in Various Reflectors

Details of benchmark neutron multiplicity measurements of the 4.484 kg Beryllium Reflected Plutonium (BeRP) ball inside of various reflectors. Measurements were performed with an Ortec Fission Meter neutron multiplicity counter. Measurements were made of the bare BeRP Ball, the BeRP Ball inside 3 inch thick polyethylene, nickel, and tungsten, and the polyethylene with an additional 2 inch thick steel reflector. For every measurement, the mass m S of 240 Pu, k eff , multiplication M, and escape multiplication ME are reported. For each individual measurement, the measured mass mS of 240 Pu in the BeRP Ball was within 20.7 grams (closest edge of measurement errorbar to closest edge of errorbar for reference mS from isotopics). The combined measurement of the mass of 240 Pu m S = 267 ± 7 grams which compared very favorably to the known value from isotopics of m S = 266.8 ± 0.5 grams.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2012

Ready to Retrofit: The Process of Project Team Selection, Building Benchmarking, and Financing Commercial Building Energy Retrofit Projects

This guide presents a process for three key activities for the building owner in preparing to retrofit existing commercial buildings: selecting project teams, benchmarking the existing building, and financing the retrofit work. Although there are other essential steps in the retrofit process, the three activities presented in this guide are the critical elements where the building owner has the greatest influence on the outcome of the project.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2015

Neutron Reference Benchmark Field Specifications: ACRR Polyethylene-Lead-Graphite (PLG) Bucket Environment (ACRR-PLG-CC-32-CL)

This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the Polyethylene-Lead-Graphite (PLG) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 37 integral dosimetry measurements in the neutron field are reported.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Neutron Reference Benchmark Field Specification: ACRR 44 Inch Lead-Boron (LB44) Bucket Environment (ACRR-LB44-CC-32-CL)

This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity with the 44 inch Lead-Boron (LB44) bucket, reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Neutron Reference Benchmark Field Specification: ACRR Free-Field Environment (ACRR-FF-CC-32-CL)

This report was put together to support the International Atomic Energy Agency (IAEA) REAL- 2016 activity to validate the dosimetry community’s ability to use a consistent set of activation data and to derive consistent spectral characterizations. The report captures details of integral measurements taken in the Annular Core Research Reactor (ACRR) central cavity free-field reference neutron benchmark field. The field is described and an “a priori” calculated neutron spectrum is reported, based on MCNP6 calculations, and a subject matter expert (SME) based covariance matrix is given for this “a priori” spectrum. The results of 31 integral dosimetry measurements in the neutron field are reported.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Summary of FY15 Results of Benchmark Modeling Activities

Sandia is participating in the third phase of and is a contributing partner to a U.S.- German “Joint Project” entitled “Comparison of current constitutive models and simulation procedures on the basis of model calculations of the thermo-mechanical behavior and healing of rock salt.” The first goal of the project is to check the ability of numerical modeling tools to correctly describe the relevant deformation phenomena in rock salt under various influences. Achieving this goal will lead to increased confidence in the results of numerical simulations related to the secure storage of radioactive wastes in rock salt, thereby enhancing the acceptance of the results. These results may ultimately be used to make various assertions regarding both the stability analysis of an underground repository in salt, during the operating phase, and the long-term integrity of the geological barrier against the release of harmful substances into the biosphere, in the post-operating phase. Among the numerical modeling tools required to address this are constitutive models that are used in computer simulations for the description of the thermal, mechanical, and hydraulic behavior of the host rock under various influences and for the long-term prediction of this behavior into the future. A second goal of the project is to investigate and demonstrate the possibilities for further potential development and improvement of these constitutive models. This report summarizes the efforts undertaken during FY15 in support of this international U.S.-German benchmark initiative.

58 GEOSCIENCES↗
DOE OSTI2015

U.S. Photovoltaic Prices and Cost Breakdowns. Q1 2015 Benchmarks for Residential, Commercial, and Utility-Scale Systems

The price of photovoltaic (PV) systems in the United States (i.e., the cost to the system owner) has continued to decline across all major market sectors. This report provides a Q1 2015 update regarding the prices of residential, commercial, and utility scale PV systems, based on an objective methodology that closely approximates the book value of a PV system. Several cases are benchmarked to represent common variations in business models, labor rates, and system architecture choice. We estimate a weighted-average cash purchase price of $3.09/W for residential scale rooftop systems, $2.15/W for commercial scale rooftop systems, $1.77/W for utility scale systems with fixed mounting structures, and $1.91/W for utility scale systems using single-axis trackers. All systems are modeled assuming standard-efficiency, polycrystalline-silicon PV modules, and further assume installation within the United States.

14 SOLAR ENERGY↗
DOE OSTI2016

East Bay Area Benchmark Study

This report is a benchmarking studying for the Sandia Create Project provided by Cornerstone Project Management, Inc.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2016

The Benchmark Extensible Tractable Testbed Engineering Resource (BETTER)

The Benchmark Extensible Tractable Testbed Engineering Resource (BETTER) is proposed as a family of modular test bodies that are intended to support engineering capability development by helping to identify weaknesses and needs. Weapon systems, subassemblies, and components are often complex and difficult to test and analyze, resulting in low confidence and high uncertainties in experimental and simulated results. The complexities make it difficult to distinguish between inherent uncertainties and errors due to insufficient capabilities. BETTER test bodies will first use simplified geometries and materials such that testing, data collection, modeling and simulation can be accomplished with high confidence and low uncertainty. Modifications and combinations of simple and well-characterized BETTER test bodies can then be used to increase complexity in order to reproduce relevant mechanics and identify weaknesses. BETTER can provide both immediate and long-term improvements in testing and simulation capabilities. This document presents the motivation, concept, benefits and examples for BETTER.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2016

U.S. Solar Photovoltaic System Cost Benchmark: Q1 2016

NREL has been modeling U.S. photovoltaic (PV) system costs since 2009. This report benchmarks costs of U.S. solar PV for residential, commercial, and utility-scale systems built in the first quarter of 2016 (Q1 2016). Our methodology includes bottom-up accounting for all system and project-development costs incurred when installing residential, commercial, and utility-scale systems, and it models the capital costs for such systems.

14 SOLAR ENERGY↗
DOE OSTI2016

Engine Benchmarking - Final CRADA Report

Detailed benchmarking of the powertrains of three light-duty vehicles was performed. Results were presented and provided to CRADA partners. The vehicles included a MY2011 Audi A4, a MY2012 Mini Cooper and a MY2014 Nissan Versa.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

Benchmarking transition energies and emission strengths for X-ray astrophysics with measurements at the Livermore EBITs

K-shell transitions in astrophysically abundant metals and L-shell transitions in Fe group elements show characteristic signatures in the soft X-ray spectrum in the energy range 0.1–10 keV. These signatures have great diagnostic value for plasma parameters such as electron and ion temperatures and densities, and can thus help understand the physics controlling the energetic processes in astrophysical sources. This diagnostic power increases with advances in spectral resolution and effective area of the employed X-ray observatories. However, to make optimal use of the diagnostic potential – whether through global spectral modeling or through diagnostics from local modeling of individual lines – the underlying atomic physics has to be complete and well known. With the next generation of soft X-ray observatories featuring micro-calorimeters such as the SXS on Astro- H/Hitomi and the X-IFU on Athena, broadband high-resolution spectroscopy with large effective area will become more commonly available in the next decade. With these spectrometers, the accuracy of the plasma parameters derived from spectral modeling will be limited by the uncertainty of the reference atomic data rather than by instrumental factors, as is sometimes already the case for the high-resolution grating observations with Chandra-HETG and XMM-Newton-RGS. To take full advantage of the measured spectra, assessment of the accuracy of and improvements to the available atomic reference data are therefore important. Dedicated measurements in the laboratory are essential to benchmark the theoretical calculations providing the bulk of the reference data used in astrophysics. Experiments at the Lawrence Livermore National Laboratory electron beam ion traps (EBIT-I and SuperEBIT) have a long history of providing this service. In this work, I present new measurements of transition energies and absolute electron impact excitation cross sections geared towards currently open atomic physics data needs.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Benchmarking of DFLAW Solid Secondary Wastes and Processes with UK/Europe Counterparts

This report provides information and background on UK solid wastes and waste processes that are similar to those which will be generated by the Direct-Feed Low Activity Waste (DFLAW) facilities at Hanford. The aim is to further improve the design case for stabilizing and immobilizing of solid secondary wastes, establish international benchmarking and review possibilities for innovation.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

BIGHORN Computational Fluid Dynamics Theory, Methodology, and Code Verification & Validation Benchmark Problems

This document presents the theoretical background for a hybrid finite-element / finite-volume fluid flow solver, namely BIGHORN, based on the Multiphysics Object Oriented Simulation Environment (MOOSE) computational framework developed at the Idaho National Laboratory (INL). An overview of the numerical methods used in BIGHORN are discussed and followed by a presentation of the formulation details. The document begins with the governing equations for the compressible fluid flow, with an outline of the requisite constitutive relations. A second-order finite volume method used for solving the compressible fluid flow problems is presented next. A Pressure-Corrected Implicit Continuous-fluid Eulerian (PCICE) formulation for time integration is also presented. The multi-fluid formulation is being developed. Although multi-fluid is not fully-developed, BIGHORN has been designed to handle multi-fluid problems. Due to the flexibility in the underlying MOOSE framework, BIGHORN is quite extensible, and can accommodate both multi-species and multi-phase formulations. This document also presents a suite of verification & validation benchmark test problems for BIGHORN. The intent for this suite of problems is to provide baseline comparison data that demonstrates the performance of the BIGHORN solution methods on problems that vary in complexity from laminar to turbulent flows. Wherever possible, some form of solution verification has been attempted to identify sensitivities in the solution methods, and suggest best practices when using BIGHORN.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

L2 Milestone: Neutron Capture Cross Sections from Surrogate (p, d) Measurements: Determination of the Unknown 87 Y(n, g) Cross Section and Assessment of the Method Via the 90 Zr(n, g) Benchmark Case: Theory Report

Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Here we describe a method for extracting cross sections for neutron-capture on unstable isotopes from indirect (surrogate) measurements. The surrogate reaction, which produces the compound nucleus of interest, has to be described and the decay of the nucleus has to be modeled. We outline the approach for one-neutron pickup and report on the determination of the 90 Zr(n, γ ) reaction from surrogate 92 Zr(p,d) data, which is compared to the directly-measured capture cross section and thus provides a benchmark for the method. We then apply the method to determine the 87 Y(n, γ ) cross section, which has not been measured directly. The work was carried out in the context of an LLNL L2 Milestone. This report addresses the theory aspects of the milestone. A complementary document summarizes the experimental efforts [1].

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

Evaluation of U.S. Building Energy Benchmarking and Transparency Programs: Attributes, Impacts, and Best Practices

In the last decade, a new policy area has emerged to boost energy efficiency in buildings that focuses on the simple action of measuring energy use as compared to buildings of similar type and size, and making that data publicly available. These efforts, referred to as benchmarking and transparency (B&T) policies, seek to unlock new energy efficiency opportunities in the country’s existing buildings by promoting data-driven decision-making and creating stronger market signals. This report focuses on the 24 state and local jurisdictions that (as of December 31, 2016) require owners of privately owned commercial buildings, multifamily buildings, or both to comply with a B&T policy. The report provides a summary of U.S. B&T policy design and implementation characteristics, reports results and impacts for jurisdictions with B&T policies, and discusses opportunities for increasing the efficacy of B&T policies, as well as suggested areas for further research. Among the findings, all but one of the B&T policy evaluation studies reviewed indicate some reduction (from 1.6% to 14%) in energy use, energy costs, or energy intensity over the two- to four-year period of the analyses. More specifically, most of the studies reviewed indicate 3% to 8% reductions in gross energy consumption or energy use intensity over a two- to four-year period of B&T policy implementation. Two additional evaluation studies indicate that there is a causal relationship between B&T policies and energy savings or energy cost savings. These documented impacts should be reviewed with some caution. While consistently showing energy savings benefits associated with B&T policies, these savings estimates should be considered preliminary because of the limited period of analyses and inconsistencies in analysis methods for the various studies. A nationally standardized method for data collection, reporting, and evaluation of B&T policies—developed with an advisory group of state and local jurisdictions, energy efficiency and evaluation experts, building owner and real estate associations, and other stakeholders—could improve the consistency and quality of B&T impact studies, providing policymakers and others with a more complete understanding of the present and future impacts of these policies.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗