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At least 487 records · Page 27

Calibration and Forward Uncertainty Propagation for Large-eddy Simulations of Engineering Flows

The objective of this work is to investigate the efficacy of using calibration strategies from Uncertainty Quantification (UQ) to determine model coefficients for LES. As the target methods are for engineering LES, uncertainty from numerical aspects of the model must also be quantified. 15 The ultimate goal of this research thread is to generate a cost versus accuracy curve for LES such that the cost could be minimized given an accuracy prescribed by an engineering need. Realization of this goal would enable LES to serve as a predictive simulation tool within the engineering design process.

42 ENGINEERING↗

Expert Meeting Report: Cladding Attachment Over Exterior Insulation

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. The location of the insulation to the exterior of the structure has many direct benefits including better effective R-value from reduced thermal bridging, better condensation resistance, reduced thermal stress on thestructure, as well as other commonly associated improvements such as increased air tightness and improved water management (Hutcheon 1964, Lstiburek 2007). The intent of the meeting was to review the current state of industry knowledge regarding cladding attachment over exterior insulation with a specific focus on: 1. Gravity load resistance, 2. Wind load resistance. The presentations explorethese topics from an engineering design, laboratory testing, field monitoring, as well as practical construction perspective. By bringing various groups together (who have been conduction research or have experience in this area), a more holistic review of the design limits and current code language proposals can be completed and additional gaps identified. The results of which will help informdesign standards and criteria.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Fermilab Recycler Collimation System Design

To provide 700 kW proton beams for neutrino production in the NuMI facility, we employ slip stacking in the Recycler with transfer to the Main Injector for recapture and acceleration. Slip stacking with 12 Booster batches per 1.33 sec cycle of the Main Injector has been implemented and briefly tested while extensive operation with 8 batches and 10 batches per MI cycle has been demonstrated. Operation in this mode since 2013 shows that loss localization is an essential component for long term operation. Beam loss in the Recycler will be localized in a collimation region with design capability for absorbing up to 2 kW of lost protons in a pair of 20-Ton collimators (absorbers). This system will employ a two stage collimation with a thin molybdenum scattering foil to define the bottom edge of both the injected and decelerated-for-slipping beams. Optimization and engineering design of the collimator components and radiation shielding are based on comprehensive MARS15 simulations predicting high collimation efficiency as well as tolerable levels of prompt and residual radiation. The system installation during the Fermilab 2016 facility shutdown will permit commissioning in the subsequent operating period.

43 PARTICLE ACCELERATORS↗

Conceptual Design Parameters for HFIR LEU U-Mo Fuel Conversion Experimental Irradiations

The High Flux Isotope Reactor (HFIR) is a versatile research reactor that is operated at the Oak Ridge National Laboratory (ORNL). The HFIR core is loaded with high-enriched uranium (HEU) and operates at a power level of 85 MW. The primary scientific missions of the HFIR include cold and thermal neutron scattering, materials irradiation, and isotope production. An engineering design study of the conversion of the HFIR from HEU to low-enriched uranium (LEU) fuel is ongoing at the Oak Ridge National Laboratory. The LEU fuel considered is based on a uranium-molybdenum alloy that is 10 percent by weight molybdenum (U-10Mo) with a 235 U enrichment of 19.75 wt %. The LEU core design discussed in this report is based on the design documented in ORNL/TM-2010/318. Much of the data reported in Sections 1 and 2 of this document was derived from or taken directly out of ORNL/TM-2010/318. The purpose of this report is to document the design parameters for and the anticipated normal operating conditions of the conceptual HFIR LEU fuel to aid in developing requirements for HFIR irradiation experiments.

Chandler, David↗

Design Considerations for the Field Use of International Nuclear Safeguards Technology

The process of developing and deploying safeguards technology should be carried out in such a way that it supports the International Atomic Energy Agency’s (IAEA’s) international safeguards verification mission, while also being efficient in terms of both cost and time. This process, however, may be hindered by a general lack of nuclear facility operating experience among the scientists or engineers designing safeguards technology, or the inability to interact with the IAEA inspector end user. As a result, equipment designers may have difficulty understanding inspector needs and the limitations of using safeguards technology in the field, often leading to inefficiencies (in the form of increased cost and time spent) in the safeguards technology design process. Here, to mitigate this knowledge gap, the Y-12 National Security Complex in Oak Ridge, Tennessee, has developed design considerations that should be incorporated into safeguards technologies, focusing on non-destructive assay equipment. Timelines for integration of these considerations into the design process are also discussed.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

A Methodology to Support the Development of a New State Vision for the U.S. Nuclear Industry

Recent changes in natural gas prices combined with reduced capital costs for solar and wind systems has created challenges for the continued operation of existing nuclear power plants (NPPs) in the United States. A new strategy in the way in which U.S. NPPs are operated, maintained, and supported is needed. One such strategy is to transform the NPP operating model through a business-driven approach that leverages technology to enable new capabilities that improve performance and reduce costs. This paper presents a methodology for developing an achievable yet transformative new state vision that ensures the continued safe and efficient operations of the U.S. NPP fleet. Here this work builds on existing guidance and leverages previous research to comprehensively address both utility needs and high-level human factors engineering design principles when developing a new state vision. The proposed methodology is intended to provide industry-wide guidance for developing a new state vision that leverages both the selected vendor’s capabilities in a way that meets the utility’s modernization goals while ensuring state-of-the-art systems engineering and human factors engineering principles are applied that promote overall plant safety, performance, and efficiency.

99 GENERAL AND MISCELLANEOUS↗

Texas Hydrogen Highway Fuel Cell Hybrid Bus and Fueling Infrastructure Technology Showcase (Final Scientific/Technical Report)

The Texas Hydrogen Highway project has showcased a hydrogen fuel cell transit bus and hydrogen fueling infrastructure that was designed and built through previous support from various public and private sector entities. The aim of this project has been to increase awareness among transit agencies and other public entities on these transportation technologies, and to place such technologies into commercial applications, such as a public transit agency. The initial project concept developed in 2004 was to show that a skid-mounted, fully-integrated, factory-built and tested hydrogen fueling station could be used to simplify the design, and lower the cost of fueling infrastructure for fuel cell vehicles. The approach was to design, engineer, build, and test the integrated fueling station at the factory then install it at a site that offered educational and technical resources and provide an opportunity to showcase both the fueling station and advanced hydrogen vehicles. The two primary technology components include: Hydrogen Fueling Station: The hydrogen fueling infrastructure was designed and built by Gas Technology Institute primarily through a funding grant from the Texas Commission on Environmental Quality. It includes hydrogen production, clean-up, compression, storage, and dispensing. The station consists of a steam methane reformer, gas clean-up system, gas compressor and 48 kilograms of hydrogen storage capacity for dispensing at 5000 psig. The station is skid-mounted for easy installation and can be relocated if needed. It includes a dispenser that is designed to provide temperature compensated fills using a control algorithm. The total station daily capacity is approximately 50 kilograms. Fuel Cell Bus: The transit passenger bus built by Ebus, a company located in Downey, CA, was commissioned and acquired by GTI prior to this project. It is a fuel cell plug-in hybrid electric vehicle which is ADA compliant, has air conditioning sufficient for Texas operations, and regenerative braking for battery charging. It uses a 19.3 kW Ballard PEM fuel cell, will store 12.6 kg of hydrogen at 350 Bar, and includes a 60 kWh battery storage system. The objectives of the project included the following: (a) To advance commercialization of hydrogen-powered transit buses and supporting infrastructure; (b) To provide public outreach and education by showcasing the operation of a 22-foot fuel cell hybrid shuttle bus and Texas first hydrogen fueling infrastructure; and (c) To showcase operation of zero-emissions vehicle for potential transit applications. As mentioned above, the project successfully demonstrated an early vehicle technology, the Ebus plug-in hybrid fuel cell bus, and that success has led to the acquisition of a more advanced vehicle that can take advantage of the same fueling infrastructure. Needed hydrogen station improvements have been identified that will enhance the capabilities of the fueling infrastructure to serve the new bus and to meet the transit agency needs. Over the course of this project, public officials, local government staff, and transit operators were engaged in outreach and education activities that acquainted them with the real world operation of a fuel cell bus and fueling infrastructure. Transit staff members in the Dallas/Ft. Worth region were invited to a workshop in Arlington, Texas at the North Central Texas Council of Governments to participate in a workshop on hydrogen and fuel cells, and to see the fuel cell bus in operation. The bus was trucked to the meeting for this purpose so that participants could see and ride the bus. Austin area transit staff members visited the fueling site in Austin to be briefed on the bus and to participate in a fueling demonstration. This led to further meetings to determine how a fuel cell bus and fueling station could be deployed at Capital Metro Transit. Target urban regions that expressed additional interest during the project in response to the outreach meetings and showcase events include San Antonio and Austin, Texas. In summary, the project objectives were achieved in the following ways: Through presentations and papers provided to a variety of audiences in multiple venues, the project team fulfilled its goal of providing education and outreach on hydrogen technology to statewide audiences. The project team generated interest that exists well beyond the completion of the project, and indeed, helped to generate financial support for a subsequent hydrogen vehicle project in Austin. The University of Texas, Center for ElectroMechanics operated the fuel cell-electric Ebus vehicle for over 13,000 miles in Austin, Texas in a variety of routes and loading configurations. The project took advantage of prior efforts that created a hydrogen fueling station and fuel cell electric-hybrid bus and continued to verify their technical foundation, while informing and educating potential future users of how these technologies work.

03 NATURAL GAS↗

An Approach to Upscaling SPPARKS Generated Synthetic Microstructures of Additively Manufactured Metals

Additive manufacturing (AM) of metal parts can save time, energy, and produce parts that cannot otherwise be made with traditional machining methods. Near final part geometry is the goal for AM, but material microstructures are inherently different from those of wrought materials as they arise from a complex temperature history associated with the additive process. It is well known that strength and other properties of interest in engineering design follow from microstructure and temperature history. Because of complex microstructure morphologies and spatial heterogeneities, properties are heterogeneous and reflect underlying microstructure. This report describes a method for distributing properties across a finite element mesh so that effects of complex heterogeneous microstructures arising from additive manufacturing can be systematically incorporated into engineering scale calculations without the need for conducting a nearly impossible and time consuming effort of meshing material details. Furthermore, the method reflects the inherent variability in AM materials by making use of kinetic Monte Carlo calculations to model the AM process associated with a build.

36 MATERIALS SCIENCE↗

Methods for Microgrid Protection (Literature Review)

This work reviews existing conventional and non-conventional protection schemes for grid- and islanded-connected mode operations in North American microgrid projects. The protection schemes applied for the microgrid projects had different types of distributed energy resources (DERs), and integrated the hydropower/diesel generators, gas/steam/wind turbines and photovoltaic (PV) systems with energy storages. In this work, conventional protection schemes were those defined within the IEEE Standard C37.2-2008, while non-conventional schemes were those not defined within this Standard. The pros and cons of conventional and non-conventional protection schemes applied in microgrid projects were discussed in detail. The overvoltage, undervoltage and frequency elements were the most common conventional protection schemes applied in microgrid projects in North America. These protection elements were used to detect the islanded conditions and faults that could not be sensed by overcurrent relays because the small fault currents contributed by the low-inertia DERs and power-electronic sources. The directional overcurrent elements allowed to distinguish between external (grid) and internal (microgrid) faults. The adaptive protection was the most popular non-conventional protection scheme applied in microgrid projects. The adaptive protection detected if the microgrid was set in grid- or islanding-connected modes and selected the relay settings for the actual microgrid conditions to avoid relays’ misoperations. In conclusion, each microgrid project can confront different types of DERs and operation modes that require individual studies to solve their protection and control challenges, to obtain the best technical and economical solution. The protection scheme results and discussions for North American microgrid projects collected in this report provides an important information to guide protection and control engineers, designers and researchers in defining the protection methods for microgrids based on the types of DERs and grid- or islanded-connected operational modes

24 POWER TRANSMISSION AND DISTRIBUTION↗

Development of an Optimized Gasoline Surrogate Formulation for PACE Experiments and Simulations

New powertrain solutions are needed to address societal challenges stemming in part from a transportation sector which relies heavily on combustion of conventional hydrocarbon fuels like gasoline. One way to advance new solutions is through predictive simulations. Predictive simulations can potentially limit the extent of experimental validations, reduce time spent in engineering design cycles, unlock new strategies for high efficiency combustion with power density, and minimize tailpipe emissions. However, the simulation tools currently available are either too computationally expensive, inadequate in their accuracy, or a combination of the two. A DOE-funded consortium of national laboratories called the Partnership to Advance Combustion Engines (PACE) seeks to address this gap by rapidly delivering new knowledge and tools which enable market-competitive powertrain solutions for light-duty vehicles. Approaches to modeling combustion in powertrain systems typically incorporate computational fluid dynamics (CFD) simulations with chemical kinetic models. These CFD simulations generally use surrogate fuels featuring a limited number of existing components in a reduced kinetic model to limit computational costs. Such surrogate fuels often sacrifice matching several or more combustion and physical properties of the target gasoline fuel. Validation of surrogate fuels is also often only pursued for a small subset of standard metrics such as research or motor octane number (RON, MON). The purpose of this project is to develop an optimal E10 gasoline surrogate fuel suitable for tasks across PACE to facilitate rapid common analysis and progression toward consortium goals. This project received contributions from tasks led by eight PACE principal investigators. The project funding here reflects all tasks under Pitz, whose tasks also contributed to additional PACE projects. Based on the optimal gasoline surrogate fuel composition, a reduced chemical kinetic model will be shared with PACE researchers, industry, and the broader combustion community.

33 ADVANCED PROPULSION SYSTEMS↗

The Untold Story of Building the First Megaton Thermonuclear Fusion Device: The Simple Element and IVY Mike

This report is a research and development engineer’s perspective on the fascinating story of the world’s first megaton-class thermonuclear device, IVY Mike (10.4 Mt). Few modern scientific endeavors have matched the complexity and breadth of scientific achievement in such a short amount of time as IVY Mike. This paper will take a look at the design, engineering, fielding, and execution of the world’s first megaton-class physics experiment by Los Alamos Scientific Laboratory and the birth of industrial liquid hydrogen use spawned by the Cold War effort. Although others have written on aspects of this technical history, they have not benefited from access to the original classified documents used by the present author. The present paper must necessarily omit some technical details that remain classified but represents the most comprehensive summary of the engineering and fabrication of the IVY Mike device in the open literature.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

A Discrete Event Simulation Approach to Nuclear Arms Enterprise Modeling and Analysis

We overview a discrete event simulation of an arms control enterprise developed to familiarize individuals with the challenges of verification and monitoring at the enterprise level. We will review the design of the simulation applied to a notional country’s nuclear arms enterprise. This simulation models how these nuclear weapons move over their lifetime from deployment, storage, maintenance, and dismantlement. With this output information, we then characterize the “ground truth” of the enterprise. Next, based on these data, we built a sophisticated analysis engine designed to provide treaty monitoring and verification information to support partner country inspectors and their evaluation. This tool was designed to be used as a game, enabling teams to compete on developing the best inspection plan to determine if the host country is complying with the conceptual treaty developed for this effort.

Pulliam, Rachel M.↗

A Mechanical Test Frame for Property Evaluations at Cryogenic Temperature

On-board storage of hydrogen fuel has been designated as a limiting factor in the advancement of fuel cell technologies in the automotive industry. The use of cryo-compressed Type III pressure vessels presents one option to overcome this barrier. These multi-material vessels will be expected to perform at high pressure and extreme low temperatures, which creates a complex engineering design challenge. Many materials exhibit highly temperature-dependent properties, which must be considered for the efficient design of cryo-compressed pressure vessels. Complicating this issue, mechanical property data at cryogenic temperatures is sparse. This technical paper provides a description of a test apparatus commissioned specifically to help address this shortcoming. A mechanical test frame was retrofitted with a continuous flow cryostat capable to evaluate various mechanical properties throughout a broad temperature range of 25 °C to -269 °C with a load limit of 10 kN. An investigation of the thermomechanical properties of an epoxy resin was carried out as a demonstration.

Mechanical characterization, cryogenic pressure ve↗

Mixing-limited Combustion of Alcohol Fuels in a Diesel Engine

Diesel-fueled, heavy-duty engines are critical to global economies, but unfortunately they are currently coupled to the rising price and challenging emissions of Diesel fuel. Public awareness and increasingly stringent emissions standards have made Diesel OEMs consider possible alternatives to Diesel, including electrification, fuel cells, and spark ignition. While these technologies will likely find success in certain market segments, there are still many applications that will continue to require the performance and liquid-fueled simplicity of Diesel-style engines. Three-way catalysis represents a possible low-cost and highly-effective pathway to reducing Diesel emissions, but that aftertreatment system has typically been incompatible with Diesel operation due to the prohibitively high levels of soot formation at the required stoichiometric fuel-air ratios. This paper explores a possible method of integrating three-way catalysis with Diesel-style engine operation. The proposed concept utilizes a high-temperature combustion system-enabled by a combination of thermal insulation, reduced turbocharger aftercooling, and exhaust gas retention-to combust low-cetane “sootless” fuels like ethanol, methanol, and natural gas in a traditional Diesel-style combustion mode (i.e. mixing-limited diffusive combustion, rather than HCCI-like strategies). The proposed concept has demonstrated the ability to meet EPA 2010 soot emissions limits without a particulate filter, while also maintaining a stoichiometric exhaust composition that is compatible with three-way catalysis. Further, the proposed concept can meet, and even exceed, baseline Diesel engine efficiency by combining the high compression ratio Diesel engine design with reduced heat transfer losses. Finally, use of mixing-limited, Diesel-style combustion drastically simplifies combustion phasing, and limits rate of rise. These early results motivate additional work on this concept, further optimizing components for high-temperature operation on alcohol fuels, and integrating the results into a commercial multi-cylinder engine demonstration.

Blumreiter, Julie↗

A direct numerical simulation study of the dilution tolerance of propane combustion under spark-ignition engine conditions

Modern spark ignition internal combustion (IC) engines rely on highly diluted fuel-air mixtures to achieve high brake thermal efficiencies. To support this, new engine designs have introduced high stroke-to-bore ratios and cylinder head designs that promote high tumble flow and turbulence intensities. However, mixture dilution through exhaust gas recirculation (EGR) is limited by combustion instabilities manifested in the form of cycle-to-cycle variability. Propane has been observed to have superior EGR dilution tolerance than gasoline, which makes it a very competitive low-carbon fuel for the new IC engines without sacrificing efficiency. Two-dimensional direct numerical simulations (DNS) are performed with detailed chemistry to study and contrast the effect of turbulence intensity and dilution on propane and iso-octane premixed flames at high pressure conditions similar to those in-cylinder. A new reduced mechanism for propane consisting of 53 transported species and 17 quasi-steady state species is developed based on a previously published mechanism and used in these simulations. Three levels of turbulence intensity and two levels of exhaust gas dilution are chosen based on conditions relevant to IC engine operation. The DNS results are analyzed based on the evolution of the flame surface area and the statistics of its driving terms, which are found to be similar for both fuels when there is no dilution but considerably different under high dilution. The analysis of the DNS data provides fundamental insights into the underlying mechanisms for improved stability under dilution.

42 ENGINEERING↗

A Multi-Dimensional Benefit Assessment of Automated Mobility Platforms (AMP) for Large Facilities: Mobility, Energy, Equity, and Facility Management & Design

The goal of the automated mobility platforms (AMPs) initiative is to raise the bar of service regarding equity and sustainability for public mobility systems that are crucial to large facilities, and doing so using electrified, energy efficient technology. Using airports as an example, the rapid growth in air travel demand has led to facility expansions and congested terminals, which directly impacts equity (e.g., increased challenges for Passengers with Reduced Mobility [PRMs]) and sustainability - both of which are important metrics often overlooked during the engineering design process. Therefore, to evaluate systems and inform critical near- and long-term decisions more effectively, a holistic evaluation framework is proposed focused on four key areas: (1) mobility, with emphasis on travel time and accessibility within an airport, (2) environment, focused on energy consumption and greenhouse gas (GHG) emissions associated with intra-airport mobility, (3) equity, specifically to the PRM community, but with an eye to the whole of society, and (4) built environment, or the fundamental changes in building design enabled by different mobility systems for larger and more flexible, functional, and energy-efficient structures. Below, AMPs are defined, and each metric is discussed further, all with a focus on airport mobility.

ADVANCED PROPULSION SYSTEMS↗

Large Pilot CAER Heat Integrated Post-combustion CO 2 Capture Technology for Reducing the Cost of Electricity

The goal of this final project report is to comprehensively summarize the work conducted on project DE-FE0026497. In accordance with the Statement of Project Objectives (SOPO), the University of Kentucky Center for Applied Energy Research (UKy-CAER) (Recipient) has developed an advanced, versatile, 10 MWe post-combustion CO 2 capture system (CCS) for a coal-fired power plant, Louisville Gas and Electric Company’s Trimble County Generating Station, using a heat integrated process combined with two-stage stripping and any advanced solvent to enhance the CO 2 absorber performance. The proposed project (Phase 1 and 2) will involve the design, fabrication, installation and testing of a large pilot scale facility that will demonstrate the UKy-CAER innovative carbon capture system integrated with an operating supercritical power plant. Specifically during Phase 1, the Recipient has provided all necessary documentation to support its Phase 2 down-selection including: the Project Narrative, the updated Project Management Plan (PMP), the preliminary engineering design, the Technical and Economic Analysis report (TEA) (including the Case 12 – Major Equipment List and submitted as a Topical Report), a Phase 1 Technology Gap Analysis (TGA), an Environmental Health and Safety (EH&S) Assessment on the 10 MWe unit, and updated Phase 2 cost estimates (including the detailed design, procurement, construction, operation, and decommissioning costs) with a budget justification. Furthermore, the Recipient has proposed a combined modular and freestanding column configuration with an advanced absorber gas/liquid distribution system, an advanced solvent, with the integration of discrete packing, a smart cross-over heat exchanger, and a load and ambient condition following control strategy, all to address ten of 12 technology gaps identified during the Phase I work. If successful, the proposed heat integrated post-combustion CCS will pave the way to achieve the United States Department of Energy National Energy Technology Laboratory (U.S. DOE NETL) CO 2 capture performance and cost target, as indicated in the submitted TEA and summarized in this report.

01 COAL, LIGNITE, AND PEAT↗

Seismic fragility analysis for lateral supports of HTR-PM RPV - 18521

Since Fukushima accident, there has been increasing interest in China to study the risks of nuclear power plants under seismic events that are beyond the design basis. Two methodologies are commonly being adopted for this purpose, namely the seismic probabilistic risk assessment (SPRA) and the seismic margin assessment (SMA). Fragility analysis plays an important role as it not only provides fragility curves as input for the SPRA, but also can deduce HCLPF values for the SMA. In this paper, seismic fragilities of the lateral supports of the HTR-PM reactor pressure vessel (RPV) are studied. The lateral supports are crucial to the safety of HTR-PM RPV under seismic events. As they are located at a high elevation in the reactor building, it is expected they are one of the major contributors to the seismic risk of HTR-PM. The lateral supports are first briefly introduced in terms of structural features, load conditions and stress acceptance criteria in the engineering design. Their fragilities are then analyzed by identifying basic fragility analysis variables and determining values in terms of the median and standard deviations. The associated fragility curves are finally calculated and a HCLPF value is reported. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗