Combined Effects of Gravity, Bending Moment, Bearing Clearance, and Input Torque on Wind Turbine Planetary Gear Load Sharing: Preprint (open access)

Combined Effects of Gravity, Bending Moment, Bearing Clearance, and Input Torque on Wind Turbine Planetary Gear Load Sharing: Preprint

This computational work investigates planetary gear load sharing of three-mount suspension wind turbine gearboxes. A three dimensional multibody dynamic model is established, including gravity, bending moments, fluctuating mesh stiffness, nonlinear tooth contact, and bearing clearance. A flexible main shaft, planetary carrier, housing, and gear shafts are modeled using reduced degrees-of-freedom through modal compensation. This drivetrain model is validated against the experimental data of Gearbox Reliability Collaborative for gearbox internal loads. Planet load sharing is a combined effect of gravity, bending moment, bearing clearance, and input torque. Influences of each of these parameters and their combined effects on the resulting planet load sharing are investigated. Bending moments and gravity induce fundamental excitations in the rotating carrier frame, which can increase gearbox internal loads and disturb load sharing. Clearance in carrier bearings reduces the bearing load carrying capacity and thus the bending moment from the rotor can be transmitted into gear meshes. With bearing clearance, the bending moment can cause tooth micropitting and can induce planet bearing fatigue, leading to reduced gearbox life. Planet bearings are susceptible to skidding at low input torque.
Date: September 1, 2012
Creator: Guo, Y.; Keller, J. & LaCava, W.
Object Type: Article
System: The UNT Digital Library
Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability (open access)

Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability

The objective of this task was to determine whether ductile iron and compacted graphite iron exhibit age strengthening to a statistically significant extent. Further, this effort identified the mechanism by which gray iron age strengthens and the mechanism by which age-strengthening improves the machinability of gray cast iron. These results were then used to determine whether age strengthening improves the machinability of ductile iron and compacted graphite iron alloys in order to develop a predictive model of alloy factor effects on age strengthening. The results of this work will lead to reduced section sizes, and corresponding weight and energy savings. Improved machinability will reduce scrap and enhance casting marketability. Technical Conclusions: • Age strengthening was demonstrated to occur in gray iron ductile iron and compacted graphite iron. • Machinability was demonstrated to be improved by age strengthening when free ferrite was present in the microstructure, but not in a fully pearlitic microstructure. • Age strengthening only occurs when there is residual nitrogen in solid solution in the Ferrite, whether the ferrite is free ferrite or the ferrite lamellae within pearlite. • Age strengthening can be accelerated by Mn at about 0.5% in excess of the Mn/S balance Estimated energy savings …
Date: September 19, 2012
Creator: Richards, Von L.
Object Type: Report
System: The UNT Digital Library
User s Guide for REFoffSpec Version 1.5.4 (open access)

User s Guide for REFoffSpec Version 1.5.4

This document is a user s guide for the IDL software REFoffSpec version 1.5.4 whose purpose is to aggregate for analysis NeXus data files from the magnetism and liquids reflectometer experiments at the Oak Ridge National Laboratory Spallation Neutron Source. The software is used to scale and align multiple data files that constitute a continuous set for an experimental run. The User s Guide for REFoffSepc explains step by step the process using a specific example run. Output screens are provided to orient the user at each step. The guide documents in detail changes made to the original REFoffSpec code during the period November 2009 and January 2011. At the time of the completion of this version of the code it was accessible from the sns_tools interface as a beta version.
Date: September 1, 2012
Creator: Ward, Richard C; Bilheux, Jean-Christophe; Lauter, Valeria & Ambaye, Haile Arena
Object Type: Report
System: The UNT Digital Library
Event-by-event study of photon observables in spontaneous and thermal fission (open access)

Event-by-event study of photon observables in spontaneous and thermal fission

None
Date: September 26, 2012
Creator: Vogt, R & Randrup, J
Object Type: Article
System: The UNT Digital Library
Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011. (open access)

Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2010-November 2011.

None
Date: September 19, 2012
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Performance Characteristics of Hardware Transactional Memory for Molecular Dynamics Application on BlueGene/Q: Toward Efficient Multithreading Strategies for Large-Scale Scientific Applications (open access)

Performance Characteristics of Hardware Transactional Memory for Molecular Dynamics Application on BlueGene/Q: Toward Efficient Multithreading Strategies for Large-Scale Scientific Applications

None
Date: September 26, 2012
Creator: Kunaseth, M.; Kalia, R. K.; Nakano, A.; Vashishta, P.; Richards, D. F. & Glosli, J. N.
Object Type: Article
System: The UNT Digital Library
Analyzing the Deployment of Large Amounts of Offshore Wind to Design an Offshore Transmission Grid in the United States: Preprint (open access)

Analyzing the Deployment of Large Amounts of Offshore Wind to Design an Offshore Transmission Grid in the United States: Preprint

This paper revisits the results from the U.S. Department of Energy's '20% Wind Energy By 2030' study, which envisioned that 54 GW of offshore wind would be installed by said year. The analysis is conducted using the Regional Energy Deployment System (ReEDS), a capacity expansion model developed by the National Renewable Energy Laboratory. The model is used to optimize the deployment of the 54 GW of wind capacity along the coasts and lakes of the United States. The graphical representation of the results through maps will be used to provide a qualitative description for planning and designing an offshore grid. ReEDS takes into account many factors in the process of siting offshore wind capacity, such as the quality of the resource, capital and O&M costs, interconnection costs, or variability metrics (wind capacity value, forecast error, expected curtailment). The effect of these metrics in the deployment of offshore wind will be analyzed through examples in the results.
Date: September 1, 2012
Creator: Ibanez, E.; Mai, T. & Coles, L.
Object Type: Article
System: The UNT Digital Library

Infrastructure Analysis Tools: A Focus on Cash Flow Analysis

NREL has developed and maintains a variety of infrastructure analysis models for the U.S. Department of Energy. Business case analysis has recently been added to this tool set. This presentation focuses on cash flow analysis. Cash flows depend upon infrastructure costs, optimized spatially and temporally, and assumptions about financing and revenue. NREL has incorporated detailed metrics on financing and incentives into the models. Next steps in modeling include continuing to collect feedback on regional/local infrastructure development activities and 'roadmap' dynamics, and incorporating consumer preference assumptions on infrastructure to provide direct feedback between vehicles and station rollout.
Date: September 1, 2012
Creator: Melaina, M. & Penev, M.
Object Type: Presentation
System: The UNT Digital Library
Effects of morphology on ion transport in ionomers for energy storage. (open access)

Effects of morphology on ion transport in ionomers for energy storage.

None
Date: September 1, 2012
Creator: Frischknecht, Amalie Lucile; Alam, Todd Michael; Azoulay, Jason David; Bolintineanu, Dan; Cordaro, Joseph Gabriel; Hall, Lisa Michelle et al.
Object Type: Report
System: The UNT Digital Library
Considerations for Possible Light Impact of Spent Nuclear Fuel for Safeguards Measurements (open access)

Considerations for Possible Light Impact of Spent Nuclear Fuel for Safeguards Measurements

This effort is designed to be a preliminary study to determine the appropriateness of lightly contacting SNF with zirconium-based cladding, in wet storage, for the purpose of taking safeguards measurements. Contact will likely consist of an initial impact followed by a light tensile load on the exterior surface of the SNF cladding. In the past, concerns have been raised that contacting SNF cladding could result in a loss of long-term mechanical integrity due to crack initiation, uncontrolled crack propagation, and a mechanical exfoliation of the protective oxide layer. The mechanical integrity concerns are addressed with an analytic model that evaluates the threshold impact limits for degraded, but undamaged SNF cladding. Aqueous corrosion concerns, associated with exfoliation of the protective oxide layer, are addressed with a qualitative argument, focusing on the possible corrosion mechanisms of zirconium-based cladding.
Date: September 1, 2012
Creator: Castle, Brian K. & Ellis, Kelly D.
Object Type: Article
System: The UNT Digital Library
Logistical simulation of spent nuclear fuel disposal in a salt repository with low temperature limits. (open access)

Logistical simulation of spent nuclear fuel disposal in a salt repository with low temperature limits.

None
Date: September 1, 2012
Creator: Kalinina, Elena Arkadievna & Hardin, Ernest L.
Object Type: Report
System: The UNT Digital Library
Playing Hot and Cold: How Can Russian Heat Policy Find Its Way Toward Energy Efficiency? (open access)

Playing Hot and Cold: How Can Russian Heat Policy Find Its Way Toward Energy Efficiency?

The Russian district heating has a large energy-saving potential, and, therefore, need for investments. The scale of needed investments is significant: the government estimates that 70 percent of the district heating infrastructure needs replacement or maintenance, a reflection of decades of under investment. Government budgets will be unable to cover them, and iInvolvingement ofthe private industry will be critical to attracting the necessary investementis necessary. For private parties to invest in district heating facilities across Russia, and not only in pockets of already successful enterprises, regulators have to develop a comprehensive policy that works district heating systems under various conditionscost-reflective tariffs, metering, incentives for efficiency and social support for the neediest (instead of subsidies for all).
Date: September 15, 2012
Creator: Roshchanka, Volha & Evans, Meredydd
Object Type: Report
System: The UNT Digital Library
Wind Power Forecasting Error Distributions: An International Comparison; Preprint (open access)

Wind Power Forecasting Error Distributions: An International Comparison; Preprint

Wind power forecasting is expected to be an important enabler for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that do occur can be critical to system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.
Date: September 1, 2012
Creator: Hodge, B. M.; Lew, D.; Milligan, M.; Holttinen, H.; Sillanpaa, S.; Gomez-Lazaro, E. et al.
Object Type: Article
System: The UNT Digital Library
Final Report: MINDES - Data Mining for Inverse Design (open access)

Final Report: MINDES - Data Mining for Inverse Design

None
Date: September 18, 2012
Creator: Kamath, C
Object Type: Report
System: The UNT Digital Library
MEASUREMENTS AND ANALYSIS OF MOCK HOLDUP CONFIGURATIONS USING FAST-NEUTRON IMAGING (open access)

MEASUREMENTS AND ANALYSIS OF MOCK HOLDUP CONFIGURATIONS USING FAST-NEUTRON IMAGING

None
Date: September 1, 2012
Creator: Hausladen, Paul; Blackston, Matthew A; Liang, J Felix & Newby, Robert Jason
Object Type: Report
System: The UNT Digital Library
In-Situ Microbial Conversion of Sequestered Greenhouse Gases (open access)

In-Situ Microbial Conversion of Sequestered Greenhouse Gases

The objectives of the project are to use microbiological in situ bioconversion technology to convert sequestered or naturally-occurring greenhouse gases, including carbon dioxide and carbon monoxide, into methane and other useful organic compounds. The key factors affecting coal bioconversion identified in this research include (1) coal properties, (2) thermal maturation and coalification process, (3) microbial population dynamics, (4) hydrodynamics (5) reservoir conditions, and (6) the methodology of getting the nutrients into the coal seams. While nearly all cultures produced methane, we were unable to confirm sustained methane production from the enrichments. We believe that the methane generation may have been derived from readily metabolized organic matter in the coal samples and/or biosoluble organic material in the coal formation water. This raises the intriguing possibility that pretreatment of the coal in the subsurface to bioactivate the coal prior to the injection of microbes and nutrients might be possible. We determined that it would be more cost effective to inject nutrients into coal seams to stimulate indigenous microbes in the coal seams, than to grow microbes in fermentation vats and transport them to the well site. If the coal bioconversion process can be developed on a larger scale, then the cost to …
Date: September 6, 2012
Creator: Scott, A R; Mukhopadhyay, M & Balin, D F
Object Type: Report
System: The UNT Digital Library
RERTR-12 Insertion 2 Irradiation Summary Report (open access)

RERTR-12 Insertion 2 Irradiation Summary Report

The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.
Date: September 1, 2012
Creator: Perez, D. M.; Chang, G. S.; Wachs, D. M.; Roth, G. A. & Woolstenhulme, N. E.
Object Type: Report
System: The UNT Digital Library
Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds" (DOE/SC00002354) (open access)

Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds" (DOE/SC00002354)

Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged …
Date: September 28, 2012
Creator: DeMott, Paul J.; Prenni, Anthony J. & Kreidenweis, Sonia M.
Object Type: Report
System: The UNT Digital Library
Dynamic Aperture Calculations for the 2012 RHIC 100 Gev Polarized Proton Run (open access)

Dynamic Aperture Calculations for the 2012 RHIC 100 Gev Polarized Proton Run

N/A
Date: September 1, 2012
Creator: Y., Luo; Fischer, W.; Gu, X.; Tepikian, S. & Schoefer, V.
Object Type: Report
System: The UNT Digital Library
Expert Meeting Report: Key Innovations for Adding Energy Efficiency to Maintenance Projects (open access)

Expert Meeting Report: Key Innovations for Adding Energy Efficiency to Maintenance Projects

This report describes an expert meeting hosted by the Building America research team NAHB Research Center, which was held on February 8, 2012, in Orlando, Florida. The topic, Key Innovations for Adding Energy Efficiency to Maintenance Projects, was intended to provide direction to more focused efforts to increase the efficiency of existing homes; in this meeting, the focus was specifically for re-roofing and the opportunities for adding energy efficiency upgrades during this major home repair activity.
Date: September 1, 2012
Creator: Wood, A. & Wiehagen, J.
Object Type: Report
System: The UNT Digital Library
An efficient modeling method for thermal stratification simulation in a BWR suppression pool (open access)

An efficient modeling method for thermal stratification simulation in a BWR suppression pool

The suppression pool in a BWR plant not only is the major heat sink within the containment system, but also provides major emergency cooling water for the reactor core. In several accident scenarios, such as LOCA and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; and the pool temperature distribution also affects the NPSHa (Available Net Positive Suction Head) and therefore the performance of the pump which draws cooling water back to the core. Current safety analysis codes use 0-D lumped parameter methods to calculate the energy and mass balance in the pool and therefore have large uncertainty in prediction of scenarios in which stratification and mixing are important. While 3-D CFD methods can be used to analyze realistic 3D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, therefore long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by 1-D transient partial …
Date: September 1, 2012
Creator: Zhao, Haihua; Zou, Ling; Zhang, Hongbin; Li, Hua; Villanueva, Walter & Kudinov, Pavel
Object Type: Article
System: The UNT Digital Library
SULFUR HEXAFLUORIDE TREATMENT OF USED NUCLEAR FUEL TO ENHANCE SEPARATIONS (open access)

SULFUR HEXAFLUORIDE TREATMENT OF USED NUCLEAR FUEL TO ENHANCE SEPARATIONS

Reactive Gas Recycling (RGR) technology development has been initiated at Savannah River National Laboratory (SRNL), with a stretch-goal to develop a fully dry recycling technology for Used Nuclear Fuel (UNF). This approach is attractive due to the potential of targeted gas-phase treatment steps to reduce footprint and secondary waste volumes associated with separations relying primarily on traditional technologies, so long as the fluorinators employed in the reaction are recycled for use in the reactors or are optimized for conversion of fluorinator reactant. The developed fluorination via SF{sub 6}, similar to the case for other fluorinators such as NF{sub 3}, can be used to address multiple fuel forms and downstream cycles including continued processing for LWR via fluorination or incorporation into a aqueous process (e.g. modified FLUOREX) or for subsequent pyro treatment to be used in advanced gas reactor designs such metal- or gas-cooled reactors. This report details the most recent experimental results on the reaction of SF{sub 6} with various fission product surrogate materials in the form of oxides and metals, including uranium oxides using a high-temperature DTA apparatus capable of temperatures in excess of 1000{deg}C . The experimental results indicate that the majority of the fission products form stable …
Date: September 25, 2012
Creator: Gray, J.; Torres, R.; Korinko, P.; Martinez-Rodriguez, M.; Becnel, J.; Garcia-Diaz, B. et al.
Object Type: Report
System: The UNT Digital Library
The 12 GeV Energy Upgrade at Jefferson Laboratory (open access)

The 12 GeV Energy Upgrade at Jefferson Laboratory

Two new cryomodules and an extensive upgrade of the bending magnets at Jefferson Lab has been recently completed in preparation for the full energy upgrade in about one year. Jefferson Laboratory has undertaken a major upgrade of its flagship facility, the CW re-circulating CEBAF linac, with the goal of doubling the linac energy to 12 GeV. I will discuss here the main scope and timeline of the upgrade and report on recent accomplishments and the present status. I will then discuss in more detail the core of the upgrade, the new additional C100 cryomodules, their production, tests and recent successful performance. I will then conclude by looking at the future plans of Jefferson Laboratory, from the commissioning and operations of the 12 GeV CEBAF to the design of the MEIC electron ion collider.
Date: September 2012
Creator: Pilat, Fulvia C.
Object Type: Article
System: The UNT Digital Library
Final Report (open access)

Final Report

This project combines outcrop-scale heterogeneity characterization, laboratory experiments, and numerical simulations. The study is designed to test whether established dispersion theory accurately predicts the behavior of solute transport through heterogeneous media and to investigate the relationship between heterogeneity and the parameters that populate these models. The dispersion theory tested by this work is based upon the fractional advection-dispersion equation (fADE) model. Unlike most dispersion studies that develop a solute transport model by fitting the solute transport breakthrough curve, this project will explore the nature of the heterogeneous media to better understand the connection between the model parameters and the aquifer heterogeneity. Our work at the Colorado School of Mines was focused on the following questions: 1) What are the effects of multi-scale geologic variability on transport of conservative and reactive solutes? 2) Can those transport effects be accounted for by classical methods, and if not, can the nonlocal fractional-order equations provide better predictions? 3) Can the fractional-order equations be parameterized through a link to some simple observable geologic features? 4) Are the classical equations of transport and reaction sufficient? 5) What is the effect of anomalous transport on chemical reaction in groundwater systems? The work is predicated on the observation …
Date: September 24, 2012
Creator: Benson, David A.
Object Type: Report
System: The UNT Digital Library