Sample records for numerical modeling performance

  1. High performance computing and numerical modelling

    E-Print Network [OSTI]

    ,

    2014-01-01T23:59:59.000Z

    Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...

  2. Numeric-modeling sensitivity analysis of the performance of wind turbine arrays

    SciTech Connect (OSTI)

    Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.

    1982-06-01T23:59:59.000Z

    An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.

  3. Thermodynamic Modeling and Numerical Simulation of Single-Shaft Microturbine Performance

    E-Print Network [OSTI]

    Hao, X.; Zhang, G.; Zhou, J.; Chen, Y.

    2006-01-01T23:59:59.000Z

    's performance under off-design situations. The proposed model is validated by operational data of a commercially available micro- turbine from a reference. The result shows that the proposed mathematical model can preferably represent the quasi...

  4. Numerical Modeling of HCCI Combustion

    Broader source: Energy.gov (indexed) [DOE]

    Numerical Modeling of HCCI Combustion Salvador M. Aceves, Daniel L. Flowers, J. Ray Smith, Joel Martinez-Frias, Francisco Espinosa-Loza, Tim Ross, Bruce Buchholz, Nick...

  5. Studied models Numerical scheme

    E-Print Network [OSTI]

    Helluy, Philippe

    : Sound speed: c0 = 1500m/s Pressure: p0 = 105Pa Density: 0 = 1000kg/m3 Vapor: 1 = 1.4 (1 = 0) Water: 2. Helluy, S. M¨uller H´el`ene Mathis Micro-Macro Modelling and Simulation of Liquid-Vapour Flows #12 approximations H´el`ene Mathis Micro-Macro Modelling and Simulation of Liquid-Vapour Flows #12;Studied models

  6. 423A HIGH-PERFORMANCE COMPUTING/NUMERICAL The International Journal of High Performance Computing Applications,

    E-Print Network [OSTI]

    Higham, Nicholas J.

    423A HIGH-PERFORMANCE COMPUTING/NUMERICAL The International Journal of High Performance Computing and barriers in the development of high-performance computing (HPC) algorithms and software. The activity has computing, numerical analy- sis, roadmap, applications and algorithms, software 1 The High-performance

  7. Numerical wind speed simulation model

    SciTech Connect (OSTI)

    Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.

    1981-09-01T23:59:59.000Z

    A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.

  8. Lattice Boltzmann Model for Numerical Relativity

    E-Print Network [OSTI]

    Ilseven, E

    2015-01-01T23:59:59.000Z

    In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for Numerical Relativity. Our model is validated with well-established tests, showing good agreement with analytical solutions. Furthermore, we show that by increasing the relaxation time, we gain stability at the cost of losing accuracy, and by decreasing the lattice spacings while keeping a constant numerical diffusivity, the accuracy and stability of our simulations improves. Finally, in order to show the potential of our approach a linear scaling law for parallelisation with respect to number of CPU cores is demonstrated. Our model represents the first step in using lattice kinetic theory to solve gravitational problems.

  9. Numerical modeling of vertical cavity semiconductor lasers

    SciTech Connect (OSTI)

    Chow, W.W.; Hadley, G.R.

    1996-08-01T23:59:59.000Z

    A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.

  10. NUMERICAL MODELING OF CATHODE CONTACT MATERIAL DENSIFICATION

    SciTech Connect (OSTI)

    Koeppel, Brian J.; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2011-11-01T23:59:59.000Z

    Numerical modeling was used to simulate the constrained sintering process of the cathode contact layer during assembly of solid oxide fuel cells (SOFCs). A finite element model based on the continuum theory for sintering of porous bodies was developed and used to investigate candidate low-temperature cathode contact materials. Constitutive parameters for various contact materials under investigation were estimated from dilatometry screening tests, and the influence of processing time, processing temperature, initial grain size, and applied compressive stress on the free sintering response was predicted for selected candidate materials. The densification behavior and generated stresses within a 5-cell planar SOFC stack during sintering, high temperature operation, and room temperature shutdown were predicted. Insufficient constrained densification was observed in the stack at the proposed heat treatment, but beneficial effects of reduced grain size, compressive stack preload, and reduced thermal expansion coefficient on the contact layer densification and stresses were observed.

  11. On numerical considerations for modeling reactive astrophysical shocks

    SciTech Connect (OSTI)

    Papatheodore, Thomas L.; Messer, O. E. Bronson, E-mail: tpapathe@utk.edu, E-mail: bronson@ornl.gov [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)

    2014-02-10T23:59:59.000Z

    Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds and associated quantities is to prohibit burning inside the numerically broadened shock. We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in models of Type Ia supernovae, including potential impacts on observables.

  12. A numerical model of aerosol scavenging

    SciTech Connect (OSTI)

    Bradley, M.M.; Molenkamp, C.R.

    1991-10-01T23:59:59.000Z

    Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate.

  13. On Numerical Considerations for Modeling Reactive Astrophysical Shocks

    SciTech Connect (OSTI)

    Papatheodore, Thomas L [ORNL] [ORNL; Messer, Bronson [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds (and associated quantities) is to prohibit burning inside the numerically broadened shock (Fryxell et al. 1989). We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that, in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. (1989). In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly-resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in Type Ia supernovae.

  14. A comparative analysis of numerical simulation and analytical modeling of horizontal well cyclic steam injection

    E-Print Network [OSTI]

    Ravago Bastardo, Delmira Cristina

    2005-08-29T23:59:59.000Z

    The main objective of this research is to compare the performance of cyclic steam injection using horizontal wells based on the analytical model developed by Gunadi against that based on numerical simulation. For comparison, ...

  15. Numerical Modeling At Dixie Valley Geothermal Area (McKenna ...

    Open Energy Info (EERE)

    McKenna & Blackwell, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Dixie Valley Geothermal Area (McKenna &...

  16. Numerical Modeling of the Nucleation Conditions of Petal-Centerline...

    Open Energy Info (EERE)

    Coso Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Numerical Modeling of the Nucleation Conditions of...

  17. Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media Q.-A. Ta numerical experiments that were performed on wave propagation in a randomly generated anisotropic used for the propagation of waves in geophysical media are not compatible with the surface recordings

  18. Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models

    E-Print Network [OSTI]

    Tackley, Paul J.

    Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models John W. Hernlund,1,2 Paul J. Tackley,1,3 and David J. Stevenson4 Received 18 November 2006; revised 18 October 2007 diffusely extending lithosphere is studied using numerical convection models covering a wide range

  19. Evolution of the Bohemian Massif: Insights from numerical modeling

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    Evolution of the Bohemian Massif: Insights from numerical modeling Petra Maierov Supervisor: Doc of Geophysics Faculty of Mathematics and Physics Charles University in Prague #12;February 4, 2013Evolution Conclusions Outline #12;February 4, 2013Evolution of the Bohemian Massif: Insights from numerical modeling 3

  20. NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE

    E-Print Network [OSTI]

    Abdou, Mohamed

    NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE Xiao-Yong Luo, Ming-Jiu Ni for multiphase flows. A con- tinuum surface force (CSF) tension model is used in the present cases. Phase change

  1. Multi-scale problems, high performance computing and hybrid numerical methods

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Multi-scale problems, high performance computing and hybrid numerical methods G. Balarac, G of High Performance Computing (HPC) is not anymore restricted to academia and scientific grand challenges

  2. Multi-scale problems, high performance computing and hybrid numerical methods

    E-Print Network [OSTI]

    Cottet, Georges-Henri

    Multi-scale problems, high performance computing and hybrid numerical methods G. Balarac, G of High Performance Computing G. Balarac LEGI, CNRS and Universite de Grenoble, BP 53, 38041 Grenoble

  3. NUMERICAL FLOW AND TRANSPORT SIMULATIONS SUPPORTING THE SALTSTONE FACILITY PERFORMANCE ASSESSMENT

    SciTech Connect (OSTI)

    Flach, G.

    2009-02-28T23:59:59.000Z

    The Saltstone Disposal Facility Performance Assessment (PA) is being revised to incorporate requirements of Section 3116 of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA), and updated data and understanding of vault performance since the 1992 PA (Cook and Fowler 1992) and related Special Analyses. A hybrid approach was chosen for modeling contaminant transport from vaults and future disposal cells to exposure points. A higher resolution, largely deterministic, analysis is performed on a best-estimate Base Case scenario using the PORFLOW numerical analysis code. a few additional sensitivity cases are simulated to examine alternative scenarios and parameter settings. Stochastic analysis is performed on a simpler representation of the SDF system using the GoldSim code to estimate uncertainty and sensitivity about the Base Case. This report describes development of PORFLOW models supporting the SDF PA, and presents sample results to illustrate model behaviors and define impacts relative to key facility performance objectives. The SDF PA document, when issued, should be consulted for a comprehensive presentation of results.

  4. Material model library for explicit numerical codes

    SciTech Connect (OSTI)

    Hofmann, R.; Dial, B.W.

    1982-08-01T23:59:59.000Z

    A material model logic structure has been developed which is useful for most explicit finite-difference and explicit finite-element Lagrange computer codes. This structure has been implemented and tested in the STEALTH codes to provide an example for researchers who wish to implement it in generically similar codes. In parallel with these models, material parameter libraries have been created for the implemented models for materials which are often needed in DoD applications.

  5. A numerical model of perturbation gas chromatography

    E-Print Network [OSTI]

    DeBarro, Marc Joseph

    1985-01-01T23:59:59.000Z

    the polymer and the solvent. Flory (1965) extended his original model to account for the volume changes in the polymer phase. A further model was suggested by Sanchez and Lacombe (1978) based on s. lattice fluid theory. For the system examined in this work...

  6. 2014 PV Performance Modeling Workshop

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2014 PV Performance Modeling Workshop Photo courtesy of Sempra Energy 8:00 AM to 9:00 PM Monday, May 5, 2014 At Biltmore Hotel, Santa Clara, California 512014 Agenda: Start Time...

  7. Numerical studies of a simple Coulomb blockade model

    E-Print Network [OSTI]

    Shao, Jianfeng

    1991-01-01T23:59:59.000Z

    NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1991... Major Subject: Physics NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Approved as to style and content by: Roland E, Allen (Chair of Committee) /, 1 r oseph H. R s ( Member) Chin B. Su (Member) Richard L...

  8. Numerical simulation of sandstone reservoir models

    E-Print Network [OSTI]

    Gross, Stephen Joseph

    1983-01-01T23:59:59.000Z

    . Case 3 - Alternatin h1 h and low ermeabilities Waterflood performance of the Case 3 reservoir is shown in Figures 19 and 20. The process 1s practically rate insensitive for both the high and low viscosity ratio cases because of the ex istence... The results of the water flood study indicate that lower rates result i n higher waterflood oil recoveries from heterogeneous reservoirs, particularly where high oil-water viscosity ratios exist. These results support the conclusions of Jordan et. al...

  9. Methodology for updating numerical predictions of excavation performance

    E-Print Network [OSTI]

    Corral Jofr, Gonzalo Andrs

    2013-01-01T23:59:59.000Z

    Due to the usual limitations in site investigations and measurements of soil properties, simplified constitutive models are routinely used in geotechnical analyses for the design of excavation support systems. However, ...

  10. Category:Numerical Modeling | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here. Category:Conceptual ModelLists forMercury VaporTemplatespage? For

  11. Air Conditioner Compressor Performance Model

    SciTech Connect (OSTI)

    Lu, Ning; Xie, YuLong; Huang, Zhenyu

    2008-09-05T23:59:59.000Z

    During the past three years, the Western Electricity Coordinating Council (WECC) Load Modeling Task Force (LMTF) has led the effort to develop the new modeling approach. As part of this effort, the Bonneville Power Administration (BPA), Southern California Edison (SCE), and Electric Power Research Institute (EPRI) Solutions tested 27 residential air-conditioning units to assess their response to delayed voltage recovery transients. After completing these tests, different modeling approaches were proposed, among them a performance modeling approach that proved to be one of the three favored for its simplicity and ability to recreate different SVR events satisfactorily. Funded by the California Energy Commission (CEC) under its load modeling project, researchers at Pacific Northwest National Laboratory (PNNL) led the follow-on task to analyze the motor testing data to derive the parameters needed to develop a performance models for the single-phase air-conditioning (SPAC) unit. To derive the performance model, PNNL researchers first used the motor voltage and frequency ramping test data to obtain the real (P) and reactive (Q) power versus voltage (V) and frequency (f) curves. Then, curve fitting was used to develop the P-V, Q-V, P-f, and Q-f relationships for motor running and stalling states. The resulting performance model ignores the dynamic response of the air-conditioning motor. Because the inertia of the air-conditioning motor is very small (H<0.05), the motor reaches from one steady state to another in a few cycles. So, the performance model is a fair representation of the motor behaviors in both running and stalling states.

  12. Development and validation of a vertically two-dimensional mesoscale numerical model

    E-Print Network [OSTI]

    Walters, Michael Kent

    1985-01-01T23:59:59.000Z

    values of model variables for static test and kinetic energy calculations . . . . . . . . . 25 2 Results of kinetic energy budget calculations . . 29 ? 1 -5 Surface heating rate (K s x 10 ) . . . . . . . 32 4 Initial values of variables for nonlinear.... These tests provide an important means of debugging the numerical scheme. The validation tests performed on the mesoscale model consisted of a simple static test, calculation of the mass continuity and the kinet. ic energy budget, and performing non...

  13. Numerical Models of Blackbody-Dominated GRBs

    E-Print Network [OSTI]

    Cuesta-Martnez, Carlos F; Mimica, Petar; Thne, Christina C; de Ugarte-Postigo, Antonio

    2015-01-01T23:59:59.000Z

    Blackbody-dominated (BBD) gamma-ray bursts (GRBs) are events characterized by the absence of a typical afterglow, long durations and the presence of a significant thermal component following the prompt gamma-ray emission. GRB 101225A (the `Christmas burst') is a prototype of this class. A plausible progenitor system for it, and for the BBD-GRBs, is the merger of a neutron star (NS) and a helium core of an evolved, massive star. Using relativistic hydrodynamic simulations we model the propagation of an ultrarelativistic jet through the enviroment created by such a merger and we compute the whole radiative signature, both thermal and non-thermal, of the jet dynamical evolution. We find that the thermal emission originates from the interaction between the jet and the hydrogen envelope ejected during the NS/He merger.

  14. Diffusion and Dispersion Characterization of a Numerical Tsunami Model

    E-Print Network [OSTI]

    Tolkova, Elena

    and numerical model. This plan is currently under devel- opment at the NCTR and a proof of concept has been-computed database of unit source solutions to determine the offshore tsunami waves. It then uses the MOST model (in nested grid mode) to propagate the offshore waves onshore for select regions. The critical factor

  15. Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations

    E-Print Network [OSTI]

    Burtscher, Martin

    .S.A. Abstract We numerically model the brain dy- namics during and after impulsive head translations using brain injuries appear among boxers and shaken babies despite minimal rotations of their heads. Modeling head translations also helps understand the brain dynamics during head rotations about an arbitrary

  16. Numerical modelling and analysis of a room temperature magnetic

    E-Print Network [OSTI]

    Numerical modelling and analysis of a room temperature magnetic refrigeration system Thomas Frank and analysis of a room temperature magnetic refrigeration system Department: Fuel Cells and Solid State-dimensional mathematical model of an Active Magnetic Regenerator (AMR) system which is used for magnetic refrigeration

  17. 155: Numerical Models of Groundwater Flow and Transport

    E-Print Network [OSTI]

    Sorek, Shaul

    155: Numerical Models of Groundwater Flow and Transport EKKEHARD HOLZBECHER1 AND SHAUL SOREK2 1. #12;2402 GROUNDWATER Calibration as a task cannot be separated from the other tasks. Inverse modeling of the Negev, J. Blaustein Institutes for Desert Research, Sede Boker, Israel The article gives an introduction

  18. Numerical modelling of a radio-frequency micro ion thruster

    E-Print Network [OSTI]

    Tsay, Michael Meng-Tsuan

    2006-01-01T23:59:59.000Z

    A simple performance model is developed for an inductively-coupled radio-frequency micro ion thruster. Methods of particle and energy balance are utilized for modeling the chamber plasma discharge. A transformer model is ...

  19. Numerical modeling and experimental validation of uniform microchamber filling in centrifugal microfluidics

    E-Print Network [OSTI]

    Banerjee, Debjyoti

    microfluidics Jonathan Siegrist,*a Mary Amasia,a Navdeep Singh,b Debjyoti Banerjeeb and Marc Madoua Received 1st analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro on centrifugal microfluidic platforms, numerical modeling using the Volume of Fluids method is performed

  20. Numerical study of energy diffusion in King models

    E-Print Network [OSTI]

    Tom Theuns

    1995-11-07T23:59:59.000Z

    The energy diffusion coefficients D_n(E) (n=1,2) for a system of equal mass particles moving self-consistently in an N-body realisation of a King model are computed from the probability per unit time, P(E, Delta E), that a star with initial energy E will undergo an energy change Delta E. In turn, P is computed from the number of times during the simulation that a particle in a state of given energy undergoes a transition to another state. These particle states are defined directly from the time evolution of E by identifying them with the event occuring between two local maxima in the E(t) curve. If one assumes next that energy changes are uncorrelated between different states, one can use diffusion theory to compute D_n(E). The simulations employ N=512, 2048,... , 32768 particles and are performed using an implementation of Aarseth's direct integrator N-body1 on a massively parallel computer. The more than seven million transitions measured in the largest N simulation provide excellent statistics. The numerically determined D(E)'s are compared against their theoretical counterparts which are computed from phase-space averaged rates of energy change due to independent binary encounters. The overall agreement between them is impressive over most of the energy range, notwithstanding the very different type of approximations involved, giving considerable support to the valid usage of these theoretical expressions to simulate dynamical evolution in Fokker-Planck type calculations.

  1. Numerical

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire3627 Federal RegisterImplementation andNumerical simulations

  2. Development of a Numerical Simulator for Analyzing the Geomechanical Performance of Hydrate-Bearing Sediments

    SciTech Connect (OSTI)

    Rutqvist, Jonny; Rutqvist, J.; Moridis, G.J.

    2008-06-01T23:59:59.000Z

    In this paper, we describe the development and application of a numerical simulator that analyzes the geomechanical performance of hydrate-bearing sediments, which may become an important future energy supply. The simulator is developed by coupling a robust numerical simulator of coupled fluid flow, hydrate thermodynamics, and phase behavior in geologic media (TOUGH+HYDRATE) with an established geomechanical code (FLAC3D). We demonstrate the current simulator capabilities and applicability for two examples of geomechanical responses of hydrate bearing sediments during production-induced hydrate dissociation. In these applications, the coupled geomechanical behavior within hydrate-bearing seducements are considered through a Mohr-Coulomb constitutive model, corrected for changes in pore-filling hydrate and ice content, based on laboratory data. The results demonstrate how depressurization-based gas production from oceanic hydrate deposits may lead to severe geomechanical problems unless care is taken in designing the production scheme. We conclude that the coupled simulator can be used to design production strategies for optimizing production, while avoiding damaging geomechanical problems.

  3. Friction versus dilation revisited: Insights from theoretical and numerical models

    E-Print Network [OSTI]

    Einat, Aharonov

    Friction versus dilation revisited: Insights from theoretical and numerical models N. Makedonska,1 controlled by the frictional strength of the fault gouge, a granular layer that accumulates between the fault friction coefficient) of such granular layers is the systems resistance to dilation, a byprocess

  4. Numerical Modeling of the 2011 Tohoku Earthquake Tsunami

    E-Print Network [OSTI]

    Frandsen, Jannette B.

    Evolution of Ocean WAVEs) to reconstruct the tsunami across the Pacific and its transformation aroundNumerical Modeling of the 2011 Tohoku Earthquake Tsunami Yoshiki Yamazaki Post-doctoral Research 2011 Tohoku earthquake (Mw 9.0) generated a massive tsunami devastated the entire Pacific coast

  5. Department of Numerical Analysis Modeling the Austenite Ferrite

    E-Print Network [OSTI]

    Vuik, Kees

    Department of Numerical Analysis Modeling the Austenite Ferrite Transformation by Cellular Ferrite Transformation by Cellular Automaton Improving Interface Stability Master of Science Thesis. Computational Materials Science 48.3 (2010): 692-699] for the austenite to ferrite transformation in low

  6. Direct Numerical Simulations and Modeling of Jets in Crossflow

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies

  7. Incorporation of the capillary hysteresis model HYSTR into the numerical code TOUGH

    SciTech Connect (OSTI)

    Niemi, A.; Bodvarsson, G.S.; Pruess, K.

    1991-11-01T23:59:59.000Z

    As part of the work performed to model flow in the unsaturated zone at Yucca Mountain Nevada, a capillary hysteresis model has been developed. The computer program HYSTR has been developed to compute the hysteretic capillary pressure -- liquid saturation relationship through interpolation of tabulated data. The code can be easily incorporated into any numerical unsaturated flow simulator. A complete description of HYSTR, including a brief summary of the previous hysteresis literature, detailed description of the program, and instructions for its incorporation into a numerical simulator are given in the HYSTR user`s manual (Niemi and Bodvarsson, 1991a). This report describes the incorporation of HYSTR into the numerical code TOUGH (Transport of Unsaturated Groundwater and Heat; Pruess, 1986). The changes made and procedures for the use of TOUGH for hysteresis modeling are documented.

  8. Sandia National Laboratories: PV Performance Modeling Collaborative

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling Collaborative PV Performance Modeling Collaborative's New and Improved Website Is Launched On December 10, 2014, in Computational Modeling & Simulation, Energy,...

  9. Refined numerical models for multidimensional Type Ia supernova simulations

    E-Print Network [OSTI]

    Reinecke, M; Niemeyer, J C

    2002-01-01T23:59:59.000Z

    Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.

  10. Refined numerical models for multidimensional Type Ia supernova simulations

    E-Print Network [OSTI]

    M. Reinecke; W. Hillebrandt; J. C. Niemeyer

    2001-11-26T23:59:59.000Z

    Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.

  11. ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS

    SciTech Connect (OSTI)

    Chiswell, S.; Buckley, R.

    2009-01-15T23:59:59.000Z

    During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.

  12. Numerical study of the effect of polyurea on the performance of steel plates under blast loads

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Numerical study of the effect of polyurea on the performance of steel plates under blast loads to blast-like loads. Different thicknesses of the polyurea are considered and the effect of polyurea history: Received 28 February 2013 Available online 13 May 2013 Keywords: Polyurea DH-36 steel Blast

  13. Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling

    SciTech Connect (OSTI)

    Du, Qiang

    2014-11-12T23:59:59.000Z

    The rational design of materials, the development of accurate and efficient material simulation algorithms, and the determination of the response of materials to environments and loads occurring in practice all require an understanding of mechanics at disparate spatial and temporal scales. The project addresses mathematical and numerical analyses for material problems for which relevant scales range from those usually treated by molecular dynamics all the way up to those most often treated by classical elasticity. The prevalent approach towards developing a multiscale material model couples two or more well known models, e.g., molecular dynamics and classical elasticity, each of which is useful at a different scale, creating a multiscale multi-model. However, the challenges behind such a coupling are formidable and largely arise because the atomistic and continuum models employ nonlocal and local models of force, respectively. The project focuses on a multiscale analysis of the peridynamics materials model. Peridynamics can be used as a transition between molecular dynamics and classical elasticity so that the difficulties encountered when directly coupling those two models are mitigated. In addition, in some situations, peridynamics can be used all by itself as a material model that accurately and efficiently captures the behavior of materials over a wide range of spatial and temporal scales. Peridynamics is well suited to these purposes because it employs a nonlocal model of force, analogous to that of molecular dynamics; furthermore, at sufficiently large length scales and assuming smooth deformation, peridynamics can be approximated by classical elasticity. The project will extend the emerging mathematical and numerical analysis of peridynamics. One goal is to develop a peridynamics-enabled multiscale multi-model that potentially provides a new and more extensive mathematical basis for coupling classical elasticity and molecular dynamics, thus enabling next generation atomistic-to-continuum multiscale simulations. In addition, a rigorous study of nite element discretizations of peridynamics will be considered. Using the fact that peridynamics is spatially derivative free, we will also characterize the space of admissible peridynamic solutions and carry out systematic analyses of the models, in particular rigorously showing how peridynamics encompasses fracture and other failure phenomena. Additional aspects of the project include the mathematical and numerical analysis of peridynamics applied to stochastic peridynamics models. In summary, the project will make feasible mathematically consistent multiscale models for the analysis and design of advanced materials.

  14. Numerical Modeling of Seafloor Interation with Steel Catenary Riser

    E-Print Network [OSTI]

    You, Jung Hwan

    2012-10-19T23:59:59.000Z

    degradation it is possible to simulate the trench formation process and estimate deflections and moments along the riser length. The seabed model is used to perform parametric studies to assess the effects of stiffness, soil strength, amplitude of pipe...

  15. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    SciTech Connect (OSTI)

    White, M.J.; Wang, X.L.; /Fermilab; Brueck, H.D.; /DESY

    2011-06-10T23:59:59.000Z

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world; however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal intercepts. The model is validated by comparing the numerical model results to ideal cases where analytical equations are valid. In addition, the XFEL (X-Ray Free Electron Laser) prototype current leads are modeled and compared to the experimental results from testing at DESY's XFEL Magnet Test Stand (XMTS) and Cryomodule Test Bench (CMTB).

  16. Numerical investigation of high-pressure combustion in rocket engines using Flamelet/Progress-variable models

    E-Print Network [OSTI]

    Coclite, A; De Palma, P; Pascazio, G

    2015-01-01T23:59:59.000Z

    The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined ...

  17. Numerical Modeling of Charged Black Holes with Massive Dilaton

    E-Print Network [OSTI]

    T. L. Boyadjiev; P. P. Fiziev

    2003-11-28T23:59:59.000Z

    In this paper the static, spherically symmetric and electrically charged black hole solutions in Einstein-Born-Infeld gravity with massive dilaton are investigated numerically. The Continuous Analog of Newton Method (CANM) is used to solve the corresponding nonlinear multipoint boundary value problems (BVPs). The linearized BVPs are solved numerically by means of collocation scheme of fourth order. A special class of solutions are the extremal ones. We show that the extremal horizons within the framework of the model satisfy some nonlinear system of algebraic equations. Depending on the charge $q$ and dilaton mass $\\gamma$, the black holes can have no more than three horizons. This allows us to construct some Hermite polynomial of third order. Its real roots describe the number, the type and other characteristics of the horizons.

  18. Numerically Estimating Internal Models of Dynamic Virtual Objects

    E-Print Network [OSTI]

    Sekuler, Robert

    human subjects to manipulate a computer-animated virtual object. This virtual object (vO) was a high, human cognition, human information processing, ideal performer, internal model, virtual object, virtual, specifically how humans acquire an internal model of a dynamic virtual object. Our methodology minimizes

  19. Sandia National Laboratories: improving PV performance model...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    accuracy PV Performance Modeling Collaborative's New and Improved Website Is Launched On December 10, 2014, in Computational Modeling & Simulation, Energy, Facilities, News, News &...

  20. Sandia National Laboratories: improving PV performance model...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    technical rigor PV Performance Modeling Collaborative's New and Improved Website Is Launched On December 10, 2014, in Computational Modeling & Simulation, Energy, Facilities, News,...

  1. Predicting Improved Chiller Performance Through Thermodynamic Modeling

    E-Print Network [OSTI]

    Figueroa, I. E.; Cathey, M.; Medina, M. A.; Nutter, D. W.

    This paper presents two case studies in which thermodynamic modeling was used to predict improved chiller performance. The model predicted the performance (COP and total energy consumption) of water-cooled centrifugal chillers as a function...

  2. Fracture Density Estimation Using Spectral Analysis of Reservoir Reflections: A Numerical Modeling Approach

    E-Print Network [OSTI]

    Pearce, Fred

    2003-01-01T23:59:59.000Z

    We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir

  3. Stochastic reduced-order model for an automotive vehicle in presence of numerous local elastic modes in the low-

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Stochastic reduced-order model for an automotive vehicle in presence of numerous local elastic a high modal density in the low-frequency range, such as an automotive vehicle. This type of structure is applied on a complex computational model of an automotive vehicle. 1 INTRODUCTION This work is performed

  4. Progress report on LBL's numerical modeling studies on Cerro Prieto

    SciTech Connect (OSTI)

    Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.

    1989-04-01T23:59:59.000Z

    An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.

  5. Three-Dimensional Numerical Evaluation of Thermal Performance of Uninsulated Wall Assemblies: Preprint

    SciTech Connect (OSTI)

    Ridouane, E. H.; Bianchi, M.

    2011-11-01T23:59:59.000Z

    This study describes a detailed three-dimensional computational fluid dynamics modeling to evaluate the thermal performance of uninsulated wall assemblies accounting for conduction through framing, convection, and radiation. The model allows for material properties variations with temperature. Parameters that were varied in the study include ambient outdoor temperature and cavity surface emissivity. Understanding the thermal performance of uninsulated wall cavities is essential for accurate prediction of energy use in residential buildings. The results can serve as input for building energy simulation tools for modeling the temperature dependent energy performance of homes with uninsulated walls.

  6. Numerical modeling of multiphase plumes: a comparative study between two-fluid and mixed-fluid integral models

    E-Print Network [OSTI]

    Bhaumik, Tirtharaj

    2005-11-01T23:59:59.000Z

    Understanding the physics of multiphase plumes and their simulation through numerical modeling has been an important area of research in recent times in the area of environmental fluid mechanics. The two renowned numerical modeling types...

  7. Statistical Performance Modeling of SRAMs

    E-Print Network [OSTI]

    Zhao, Chang

    2011-02-22T23:59:59.000Z

    Yield analysis is a critical step in memory designs considering a variety of performance constraints. Traditional circuit level Monte-Carlo simulations for yield estimation of Static Random Access Memory (SRAM) cell is quite time consuming due...

  8. A numerical model of aerosol scavenging: Part 1, Microphysics parameterization

    SciTech Connect (OSTI)

    Molenkamp, C.R.; Bradley, M.M.

    1991-09-01T23:59:59.000Z

    We have developed a three-dimensional numerical model (OCTET) to simulate the dynamics and microphysics of clouds and the transport, diffusion and precipitation scavenging of aerosol particles. In this paper we describe the cloud microphysics and scavenging parameterizations. The representation of cloud microphysics is a bulk- water parameterization which includes water vapor and five types of hydrometeors (cloud droplets, rain drops, ice crystals, snow, and graupel). A parallel parameterization represents the scavenging interactions between pollutant particles and hydrometeors including collection of particles because of condensation nucleation, Brownian and phoretic attachment, and inertial capture, resuspension because of evaporation and sublimation; and transfer interactions where particles collected by one type of hydrometeor are transferred to another type of freezing, melting, accretion, riming and autoconversion.

  9. Effective viscosity of active suspensions: Three-dimensional numerical modeling

    E-Print Network [OSTI]

    Levan Jibuti; Walter Zimmermann; Salima Rafa; Philippe Peyla

    2014-12-10T23:59:59.000Z

    A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of its two flagella. The model reveals unusual angular orbits of the active swimmer under a linear shear flow. Namely, the swimmer sustains orientation transiently across the flow when flagella plane is perpendicular to the shear plane, and amplify the shear-induced rotation along the flow. Such behavior is a result of the interplay between shear-induced deformation and swimmer's periodic beating motion that exerts internal torques on the torque-free swimmer. This particular behavior has some significant consequences on the rheological properties of the suspension that tends to confirm previous experimental results [Phys. Rev. Lett. 104, 098102 (2010)]. We calculated the intrinsic viscosity of the suspension with such isolated modeled microswimmers (dilute case) in shear flow using numerical simulations based on Rotne-Prager approximation. The results show an increased intrinsic viscosity for active swimmer suspensions in comparison to non-active ones in accordance with previous experimental measurements. A major enhancement of the active swimmer viscosity occurs due to the effectively extended shape of the deformable swimming cells. We also recover the experimentally observed shear thinning behavior.

  10. Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory

    E-Print Network [OSTI]

    Zhihao Ge; Ruihua Li

    2014-12-25T23:59:59.000Z

    In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.

  11. Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory

    E-Print Network [OSTI]

    Zhihao Ge; Ruihua Li

    2015-03-08T23:59:59.000Z

    In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.

  12. FREQFIT: Computer program which performs numerical regression and statistical chi-squared goodness of fit analysis

    SciTech Connect (OSTI)

    Hofland, G.S.; Barton, C.C.

    1990-10-01T23:59:59.000Z

    The computer program FREQFIT is designed to perform regression and statistical chi-squared goodness of fit analysis on one-dimensional or two-dimensional data. The program features an interactive user dialogue, numerous help messages, an option for screen or line printer output, and the flexibility to use practically any commercially available graphics package to create plots of the program`s results. FREQFIT is written in Microsoft QuickBASIC, for IBM-PC compatible computers. A listing of the QuickBASIC source code for the FREQFIT program, a user manual, and sample input data, output, and plots are included. 6 refs., 1 fig.

  13. Statistical Performance Modeling of SRAMs

    E-Print Network [OSTI]

    Zhao, Chang

    2011-02-22T23:59:59.000Z

    to their characteristic of low failure rate, while statistical method of yield sensitivity analysis is meaningful for its high efficiency. This thesis proposes a novel statistical model to conduct yield sensitivity prediction on SRAM cells at the simulation level, which...

  14. AI-Based Simulation: An Alternative to Numerical Simulation and Modeling

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    : Numerical Modeling, Simulation, Artificial Intelligence, Data Min- ing, Reservoir Modeling, Reservoir data for brown fields. The run-time of AI-Based reservoir models that provide complete field responses Computational Fluid Dynamics (CFD) to Numer- ical Reservoir Simulation (NRS) most of the computational modeling

  15. PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment

    SciTech Connect (OSTI)

    Jordan, J. M.; Flach, G. P.; Westbrook, M. L.

    2012-08-31T23:59:59.000Z

    Numerical simulations of groundwater flow and contaminant transport in the vadose and saturated zones have been conducted using the PORFLOW code in support of an overall Performance Assessment (PA) of the H-Tank Farm. This report provides technical detail on selected aspects of PORFLOW model development and describes the structure of the associated electronic files. The PORFLOW models for the H-Tank Farm PA, Rev. 1 were updated with grout, solubility, and inventory changes. The aquifer model was refined. In addition, a set of flow sensitivity runs were performed to allow flow to be varied in the related probabilistic GoldSim models. The final PORFLOW concentration values are used as input into a GoldSim dose calculator.

  16. A controlled distributed parameter model for a fluid-flexible structure system: numerical simulations and experiment validations

    E-Print Network [OSTI]

    Baudouin, Lucie

    A controlled distributed parameter model for a fluid-flexible structure system: numerical consider the problem of active reduction of vibrations in a fluid-flexible structure system and the sloshing of the fuel inside the wing's tank. The control is performed using piezoelectric patches

  17. Numerical evaluation of the thermal performances of roof-mounted radiant barriers

    E-Print Network [OSTI]

    Miranville, Frdric; Lucas, Franck; Johan, Seriacaroupin

    2014-01-01T23:59:59.000Z

    This paper deals with the thermal performances of roof-mounted radiant barriers. Using dynamic simulations of a mathematical model of a whole test cell including a radiant barrier installed between the roof top and the ceiling, the thermal performance of the roof is calculated. The mean method is more particularly used to assess the thermal resistance of the building component and lead to a value which is compared to the one obtained for a mass insulation product such as polyurethane foam. On a further stage, the thermal mathematical model is replaced by a thermo-aeraulic model which is used to evaluate the thermal resistance of the roof as a function of the airflow rate. The results shows a better performance of the roof in this new configuration, which is widely used in practice. Finally, the mathematical relation between the thermal resistance and the airflow rate is proposed.

  18. Representing Cloud Processing of Aerosol in Numerical Models

    SciTech Connect (OSTI)

    Mechem, D.B.; Kogan, Y.L.

    2005-03-18T23:59:59.000Z

    The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.

  19. Numerical modeling of an all vanadium redox flow battery.

    SciTech Connect (OSTI)

    Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.

    2014-01-01T23:59:59.000Z

    We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.

  20. Generic CSP Performance Model for NREL's System Advisor Model: Preprint

    SciTech Connect (OSTI)

    Wagner, M. J.; Zhu, G.

    2011-08-01T23:59:59.000Z

    The suite of concentrating solar power (CSP) modeling tools in NREL's System Advisor Model (SAM) includes technology performance models for parabolic troughs, power towers, and dish-Stirling systems. Each model provides the user with unique capabilities that are catered to typical design considerations seen in each technology. Since the scope of the various models is generally limited to common plant configurations, new CSP technologies, component geometries, and subsystem combinations can be difficult to model directly in the existing SAM technology models. To overcome the limitations imposed by representative CSP technology models, NREL has developed a 'Generic Solar System' (GSS) performance model for use in SAM. This paper discusses the formulation and performance considerations included in this model and verifies the model by comparing its results with more detailed models.

  1. An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling

    E-Print Network [OSTI]

    Williamson, Mark

    An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark Williamson Working Paper 83 #12;An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark for long time period simulations and large ensemble studies in Earth system models of intermediate

  2. Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk electrode N the nickel-iron electrodeposition process, we have developed one-dimensional numerical model. This model ad can predict characteristic features of the nickel-iron sys- tem. this work was supported

  3. Modeling well performance in compartmentalized gas reservoirs

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2008-10-10T23:59:59.000Z

    Predicting the performance of wells in compartmentalized reservoirs can be quite challenging to most conventional reservoir engineering tools. The purpose of this research is to develop a Compartmentalized Gas Depletion Model that applies not only...

  4. Modeling well performance in compartmentalized gas reservoirs

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2009-05-15T23:59:59.000Z

    Predicting the performance of wells in compartmentalized reservoirs can be quite challenging to most conventional reservoir engineering tools. The purpose of this research is to develop a Compartmentalized Gas Depletion Model that applies not only...

  5. Numerical modelling of hyperbolic conservation laws using bicharacteristics

    E-Print Network [OSTI]

    Hanke-Bourgeois, Martin

    volume methods -1- #12;Overview I. Hyperbolic Conservation Laws Theory of bicharacteristics and evolution, bicharacteritsics stability, accuracy, error analysis III. Numerical Experiments: Wave equation system, Euler eqs finite volume methods -2- #12; airflow hydraulic schock meteorological flow Source: efluid

  6. ASYMPTOTIC AND NUMERICAL MODELLING OF FLOWS IN FRACTURED POROUS MEDIA

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    numerical results are reported showing different kinds of flows in the case of impermeable or partially. Joliot Curie, F-13453 Marseille cedex 13. Email : [angot,fboyer,fhubert]@cmi.univ-mrs.fr cl EDP Sciences

  7. Simplified Numerical Models for Complex Air Supply Jelena Srebric*

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    greatly improve our knowledge of the performance of ventilation systems. Unfortunately, a major bottleneck

  8. MECHANICAL PROPERTY CHARACTERIZATIONS AND PERFORMANCE MODELING OF SOFC SEALS

    SciTech Connect (OSTI)

    Koeppel, Brian J.; Vetrano, John S.; Nguyen, Ba Nghiep; Sun, Xin; Khaleel, Mohammad A.

    2008-03-26T23:59:59.000Z

    This study provides modeling tools for the design of reliable seals for SOFC stacks. The work consists of 1) experimental testing to determine fundamental properties of SOFC sealing materials, and 2) numerical modeling of stacks and sealing systems. The material tests capture relevant temperature-dependent physical and mechanical data needed by the analytical models such as thermal expansion, strength, fracture toughness, and relaxation behavior for glass-ceramic seals and other materials. Testing has been performed on both homogenous specimens and multiple material assemblies to investigate the effect of interfacial reactions. A viscoelastic continuum damage model for a glass-ceramic seal was developed to capture the nonlinear behavior of this material at high temperatures. This model was implemented in the MSC MARC finite element code and was used for a detailed analysis of a planar SOFC stack under thermal cycling conditions. Realistic thermal loads for the stack were obtained using PNNLs in-house multiphysics solver. The accumulated seal damage and component stresses were evaluated for multiple thermal loading cycles, and regions of high seal damage susceptible to cracking were identified. Selected test results, numerical model development, and analysis results will be presented.

  9. Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and

    E-Print Network [OSTI]

    Sites, James R.

    Thesis Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and Explanation our supervision by Markus Gloeckler entitled "Numerical Modeling of CIGS Solar Cells: Definition. A three-layer structure, simulating a Cu(InGa)Se2 (CIGS) heterojunction solar cell, was set up using

  10. NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE

    E-Print Network [OSTI]

    Sites, James R.

    NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION Numerical modeling of polycrystalline thin-film solar cells is an important strategy to test the viability

  11. Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters

    E-Print Network [OSTI]

    Lee, Zhongping

    Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters in the upper ocean, the vertical distribution of solar radiation (ESR) in the shortwave domain plays (2005), Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal

  12. Numerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact

    E-Print Network [OSTI]

    Renard, Yves - Ple de Mathmatiques, Institut National des Sciences Appliques de Lyon

    .e. hyperbolic) model with dry friction. Since we consider a Coulomb friction law with a slip velocity dependentNumerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact in the numerical analysis of more elaborated dynamic purely elastic problems with dry friction. 2001 Elsevier

  13. ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE

    E-Print Network [OSTI]

    Loyka, Sergey

    1 ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE Sergey Loyka EMC Lab: loyka@nemc.belpak.minsk.by Abstract - Numerical EMC/EMI modeling over a wide frequency range requires computational efficiency is proposed. I. INTRODUCTION Almost all the EMC problems are wide frequency range ones

  14. Numerical modeling of roll structures in mesoscale vortexes over the Black Sea

    E-Print Network [OSTI]

    Iarova, D A

    2014-01-01T23:59:59.000Z

    This paper is a case study of horizontal atmospheric rolls that formed over the Black Sea on 16 August 2007. The rolls were discovered in WRF modeling results for a mesoscale cyclone that originated over the sea on 15 August 2007. The roll formation mechanisms, such as Rayleigh-Benard convective instability, dynamic instability, advection and stretching of vertical velocity field inhomogeneities, are considered. It is shown that indeed convective instability played an important role in the roll formation but dynamic instability did not occur. In order to distinguish other possible mechanisms of the roll formation numerical experiments were performed. In these experiments sea surface temperature in the initial conditions was decreased in order to prevent convective instability. Even though convective instability was suppressed roll-like structures still appeared in the modeling results, although their height and circulation velocity were smaller than in the control run. It was found that these structures were ...

  15. Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water Alexey, University of Virginia, USA Available online 3 February 2007 Abstract Short pulse laser interaction modeling; Nanoparticles; Cell targeting; Laser damage 1. Introduction Short pulse laser irradiation

  16. Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling

    E-Print Network [OSTI]

    Xu, Xianfan

    Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling (TEG) designed for automotive waste heat recovery systems. This model is capable of computing bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from

  17. The NINJA-2 project: Detecting and characterizing gravitational waveforms modelled using numerical binary black hole simulations

    E-Print Network [OSTI]

    The LIGO Scientific Collaboration; the Virgo Collaboration; the NINJA-2 Collaboration; :; J. Aasi; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; K. Ackley; C. Adams; T. Adams; P. Addesso; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; A. Ain; P. Ajith; A. Alemic; B. Allen; A. Allocca; D. Amariutei; M. Andersen; R. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; M. Barbet; B. C. Barish; D. Barker; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. C. Batch; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. Bejger; M. G. Beker; C. Belczynski; A. S. Bell; C. Bell; G. Bergmann; D. Bersanetti; A. Bertolini; J. Betzwieser; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Biscans; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; S. Bloemen; M. Blom; O. Bock; T. P. Bodiya; M. Boer; G. Bogaert; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; Sukanta Bose; L. Bosi; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brckner; S. Buchman; T. Bulik; H. J. Bulten; A. Buonanno; R. Burman; D. Buskulic; C. Buy; L. Cadonati; G. Cagnoli; J. Caldern Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavagli; F. Cavalier; R. Cavalieri; C. Celerier; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. J. Chamberlin; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; C. Collette; M. Colombini; L. Cominsky; M. Constancio Jr.; A. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corpuz; A. Corsi; C. A. Costa; M. W. Coughlin; S. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; R. Coyne; K. Craig; J. D. E. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; G. Debreczeni; J. Degallaix; S. Delglise; W. Del Pozzo; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. De Rosa; R. T. DeRosa; R. DeSalvo; S. Dhurandhar; M. Daz; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; A. Donath; F. Donovan; K. L. Dooley; S. Doravari; S. Dossa; R. Douglas; T. P. Downes; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; S. Dwyer; T. Eberle; T. Edo; M. Edwards; A. Effler; H. Eggenstein; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endr?czi; R. Essick; T. Etzel; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. M. Farr; M. Favata; H. Fehrmann; M. M. Fejer; D. Feldbaum; F. Feroz; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; S. Gaonkar; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; S. Ghosh; J. A. Giaime; K. D. Giardina; A. Giazotto; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. Gonzlez; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goler; R. Gouaty; C. Grf; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. Gushwa; E. K. Gustafson; R. Gustafson; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. Hart; M. T. Hartman; C. -J. Haster; K. Haughian; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; S. Hooper; P. Hopkins; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; P. Jaranowski; Y. Ji; F. Jimnez-Forteza; W. W. Johnson; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; J. Karlen; M. Kasprzack; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; F. Kawazoe; F. Kflian; G. M. Keiser; D. Keitel; D. B. Kelley; W. Kells; A. Khalaidovski

    2014-01-05T23:59:59.000Z

    The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered with false alarm rates smaller than 1 in a thousand years. Parameter estimation algorithms were run on each of these waveforms to explore the ability to constrain the masses, component angular momenta and sky position of these waveforms. We also perform a large-scale monte-carlo study to assess the ability to recover each of the 60 hybrid waveforms with early Advanced LIGO and Advanced Virgo sensitivity curves. Our results predict that early Advanced LIGO and Advanced Virgo will have a volume-weighted average sensitive distance of 300Mpc (1Gpc) for $10M_{\\odot}+10M_{\\odot}$ ($50M_{\\odot}+50M_{\\odot}$) binary black hole coalescences. We demonstrate that neglecting the component angular momenta in the waveform models used in matched-filtering will result in a reduction in sensitivity for systems with large component angular momenta. [Abstract abridged for ArXiv, full version in PDF

  18. Numerical Model of a Tensioner System and Flex Joint

    E-Print Network [OSTI]

    Huang, Han

    2013-07-27T23:59:59.000Z

    Top Tensioned Riser (TTR) and Steel Catenary Riser (SCR) are often used in a floating oil/gas production system deployed in deep water for oil transport. This study focuses on the improvements to the existing numerical code, known as CABLE3D...

  19. Numerical Modeling of Human Effect on Indoor Propagation

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    several types of obstacles such a brick enclosure walls, one metal heater, two metal wardrobes, two metal antenna placed 85 cm above the floor level. The spatial step is /10, or is the wavelength, chosen by the numerical dispersions. The choice of the spatial step is a compromise between the minimization of inaccuracy

  20. PV performance modeling workshop summary report.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Tasca, Coryne Adelle (SRA International, Inc., Fairfax, VA); Cameron, Christopher P.

    2011-05-01T23:59:59.000Z

    During the development of a solar photovoltaic (PV) energy project, predicting expected energy production from a system is a key part of understanding system value. System energy production is a function of the system design and location, the mounting configuration, the power conversion system, and the module technology, as well as the solar resource. Even if all other variables are held constant, annual energy yield (kWh/kWp) will vary among module technologies because of differences in response to low-light levels and temperature. A number of PV system performance models have been developed and are in use, but little has been published on validation of these models or the accuracy and uncertainty of their output. With support from the U.S. Department of Energy's Solar Energy Technologies Program, Sandia National Laboratories organized a PV Performance Modeling Workshop in Albuquerque, New Mexico, September 22-23, 2010. The workshop was intended to address the current state of PV system models, develop a path forward for establishing best practices on PV system performance modeling, and set the stage for standardization of testing and validation procedures for models and input parameters. This report summarizes discussions and presentations from the workshop, as well as examines opportunities for collaborative efforts to develop objective comparisons between models and across sites and applications.

  1. Fractional Calculus in Hydrologic Modeling: A Numerical Perspective

    SciTech Connect (OSTI)

    David A. Benson; Mark M. Meerschaert; Jordan Revielle

    2012-01-01T23:59:59.000Z

    Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.

  2. Radionuclide release rates from spent fuel for performance assessment modeling

    SciTech Connect (OSTI)

    Curtis, D.B.

    1994-11-01T23:59:59.000Z

    In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear fuel are presented. Each example represents a very different approach to obtaining a numerical measure and each has its limitations. There is no way to obtain an unambiguous measure of this or any parameter used in performance assessment codes for evaluating the effects of processes operative over many millennia. The examples are intended to suggest by example that in the absence of the ability to evaluate accuracy and precision, consistency of a broadly based set of data can be used as circumstantial evidence to defend the choice of parameters used in performance assessments.

  3. Numerical modeling of geothermal systems with applications to Krafla, Iceland and Olkaria, Kenya

    SciTech Connect (OSTI)

    Bodvarsson, G.S.

    1987-08-01T23:59:59.000Z

    The use of numerical models for the evaluation of the generating potential of high temperature geothermal fields has increased rapidly in recent years. In the present paper a unified numerical approach to the modeling of geothermal systems is discussed and the results of recent modeling of the Krafla geothermal field in Iceland and the Olkaria, Kenya, are described. Emphasis is placed on describing the methodology using examples from the two geothermal fields.

  4. Empirical Comparison of Statistical Pavement Performance Models

    E-Print Network [OSTI]

    sections from the American Association of State Highway Officials AASHO Road Test Highway Research BoardEmpirical Comparison of Statistical Pavement Performance Models Chih-Yuan Chu1 and Pablo L. Durango-Cohen2 Abstract: We conduct an empirical comparison of nine representative statistical pavement

  5. Climate Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Mirin, A A

    2007-02-05T23:59:59.000Z

    The Center for Applied Scientific Computing (CASC) and the LLNL Climate and Carbon Science Group of Energy and Environment (E and E) are working together to improve predictions of future climate by applying the best available computational methods and computer resources to this problem. Over the last decade, researchers at the Lawrence Livermore National Laboratory (LLNL) have developed a number of climate models that provide state-of-the-art simulations on a wide variety of massively parallel computers. We are now developing and applying a second generation of high-performance climate models. Through the addition of relevant physical processes, we are developing an earth systems modeling capability as well.

  6. Numerical simulation of a lattice polymer model at its integrable point

    E-Print Network [OSTI]

    A. Bedini; A. L. Owczarek; T. Prellberg

    2013-05-21T23:59:59.000Z

    We revisit an integrable lattice model of polymer collapse using numerical simulations. This model was first studied by Bl\\"ote and Nienhuis in J. Phys. A. {\\bf 22}, 1415 (1989) and it describes polymers with some attraction, providing thus a model for the polymer collapse transition. At a particular set of Boltzmann weights the model is integrable and the exponents $\

  7. INTERNATIONAL JOURNAL OF c 2011 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing and Information

    E-Print Network [OSTI]

    Brger, Raimund

    -dimensional model of sedimentation of suspensions of small solid particles dispersed in a viscous fluid. This model accepted spatially one-dimensional sedimentation model [35] gives rise to one scalar, nonlinear hyperbolicINTERNATIONAL JOURNAL OF c 2011 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing

  8. INTERNATIONAL JOURNAL OF c 2012 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing and Information

    E-Print Network [OSTI]

    Brger, Raimund

    -dimensional model of sedimentation of suspensions of small solid particles dispersed in a viscous fluid. This model accepted spatially one-dimensional sedimentation model [35] gives rise to one scalar, nonlinear hyperbolicINTERNATIONAL JOURNAL OF c 2012 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing

  9. Improvements on FFD Modeling by Using Different Numerical Schemes Wangda Zuo, Jianjun Hu, Qingyan Chen

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    . "Improvements on FFD modeling by using different numerical schemes," Numerical Heat Transfer, Part B (m) t time step (s) Greek Symbols ratio of mass flow rate to a flow domain over that out of the flow: Fundamentals, 58(1), 1-16. #12;2 Abstract Indoor environm ent design and air m anagement in buildings requires

  10. Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow

    E-Print Network [OSTI]

    Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2O­CO2) hydrothermal fluid flow

  11. USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS to develop a methodology to generate solar radiation maps using information from different sources. First with conclusions and next works in the last section. Keywords: Solar Radiation maps, Numerical Weather Predictions

  12. Numerical-model developments for stimulation technologies in the Eastern Gas Shales Project

    SciTech Connect (OSTI)

    Barbour, T.G.; Maxwell, D.E.; Young, C.

    1980-01-01T23:59:59.000Z

    These efforts were directed towards the development of a numerical tensile failure model that could be used to make a parameter sensitivity study of the EGSP wellbore stimulation methods for gas recovery in Devonain shales, calculations were performed using the NTS Multi-Frac Mineback Experiments as the geometry, boundary conditions and material properties of the models. Several major accomplishments were achieved during this task. These include: development of a Crack and Void Strain (CAVS) tensile failure model for one-dimensional fracture analysis using the one-dimensional geometries available in SAI's STEALTH 1-D finite-difference code; modification of the original CAVS tensile failure criteria to improve its representation of multiple fracture development by introducing a logic that adjusts the material's tensile strength (both for crack initiation and crack propagation) according to the degree of cracking that has occurred; adding a submodel to CAVS to allow for cracking propping when a crack is reclosed and to require energy to be expanded during this process; adding a submodel to CAVS to allow for crack pressurization when a crack void strain is in communication with the fluid pressure of the borehole; and performing a parameter sensitivity analysis to determine the effect that the material properties of the rock has on crack development, to include the effects of yielding and compaction. Using the CAVS model and its submodels, a series of STEALTH calculations were then performed to estimate the response of the NTS unaugmented Dynafrac experiment. Pressure, acceleration and stress time histories and snapshot data were obtained and should aid in the evaluation of these experiments. Crack patterns around the borehole were also calculated and should be valuable in a comparison with the fracture patterns observed during mineback.

  13. Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)

    SciTech Connect (OSTI)

    Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

    2014-06-01T23:59:59.000Z

    Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

  14. Powder Metal Performance Modeling of Automotive Components ?AMD...

    Energy Savers [EERE]

    Powder Metal Performance Modeling of Automotive Components AMD 410 Powder Metal Performance Modeling of Automotive Components AMD 410 Presentation from the U.S. DOE Office of...

  15. Analytical-Numerical Modeling Of Komatiite Lava Emplacement And...

    Open Energy Info (EERE)

    Modeling Of Komatiite Lava Emplacement And Thermal Erosion At Perseverance, Western Australia Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  16. Sensitivity of injection costs to input petrophysical parameters in numerical geologic carbon sequestration models

    SciTech Connect (OSTI)

    Cheng, C. L.; Gragg, M. J.; Perfect, E.; White, Mark D.; Lemiszki, P. J.; McKay, L. D.

    2013-08-24T23:59:59.000Z

    Numerical simulations are widely used in feasibility studies for geologic carbon sequestration. Accurate estimates of petrophysical parameters are needed as inputs for these simulations. However, relatively few experimental values are available for CO2-brine systems. Hence, a sensitivity analysis was performed using the STOMP numerical code for supercritical CO2 injected into a model confined deep saline aquifer. The intrinsic permeability, porosity, pore compressibility, and capillary pressure-saturation/relative permeability parameters (residual liquid saturation, residual gas saturation, and van Genuchten alpha and m values) were varied independently. Their influence on CO2 injection rates and costs were determined and the parameters were ranked based on normalized coefficients of variation. The simulations resulted in differences of up to tens of millions of dollars over the life of the project (i.e., the time taken to inject 10.8 million metric tons of CO2). The two most influential parameters were the intrinsic permeability and the van Genuchten m value. Two other parameters, the residual gas saturation and the residual liquid saturation, ranked above the porosity. These results highlight the need for accurate estimates of capillary pressure-saturation/relative permeability parameters for geologic carbon sequestration simulations in addition to measurements of porosity and intrinsic permeability.

  17. Numerical modeling of elastic wave scattering by near-surface heterogeneities

    E-Print Network [OSTI]

    Al Muhaidib, Abdulaziz

    2013-01-01T23:59:59.000Z

    A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...

  18. 2D-Modelling of pellet injection in the poloidal plane: results of numerical tests

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2D-Modelling of pellet injection in the poloidal plane: results of numerical tests P. Lalousis developed for computing the expansion of pellet-produced clouds in the poloidal plane. The expansion

  19. Seismic scattering attributes to estimate reservoir fracture density : a numerical modeling study

    E-Print Network [OSTI]

    Pearce, Frederick D. (Frederick Douglas), 1978-

    2003-01-01T23:59:59.000Z

    We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...

  20. Seismic Scattering Attributes to Estimate Reservoir Fracture Density: A Numerical Modeling Study

    E-Print Network [OSTI]

    Pearce, Frederick Douglas

    We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...

  1. A numerical analysis of condenser performance of a seawater desalination system

    E-Print Network [OSTI]

    Mohamed, Hassan, S.B. Massachusetts Institute of Technology

    2009-01-01T23:59:59.000Z

    This thesis presents the numerical analysis of three type condensers for desalination of seawater system. The condensers that were analyzed were a finned tube condenser that was built in Malaysia desalination plant, a ...

  2. Numerical simulation of the impeller tip clearance effect on centrifugal compressor performance

    E-Print Network [OSTI]

    Hoenninger, Corbett Reed

    2001-01-01T23:59:59.000Z

    This thesis presents the numerical simulation of flow in centrifugal compressors. A three-dimensional Navier-Stokes solver was employed to simulate flow through two centrifugal compressors. The first compressor simulated was the NASA low speed...

  3. System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

    SciTech Connect (OSTI)

    Freeman, J.; Whitmore, J.; Kaffine, L.; Blair, N.; Dobos, A. P.

    2013-12-01T23:59:59.000Z

    The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

  4. A robotic crawler exploiting directional frictional interactions: experiments, numerics, and derivation of a reduced model

    E-Print Network [OSTI]

    Giovanni Noselli; Antonio DeSimone

    2014-08-26T23:59:59.000Z

    We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. 'breathing-like' deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.

  5. NUMERICAL MODELING OF TURBULENT FLOW IN A COMBUSTION TUNNEL

    E-Print Network [OSTI]

    Ghoniem, A.F.

    2013-01-01T23:59:59.000Z

    1VJcDonald, H. (1979) Combustion r 1 iodeJing in Two and1979) Practical Turbulent-Combustion Interaction Models forInternation on Combustors. Combustion The 17th Symposium

  6. Numerical Modeling of Hydraulic Fracturing in Oil Sands

    E-Print Network [OSTI]

    2008-11-16T23:59:59.000Z

    A thermal hydro-mechanical fracture nite element model is developed, which is able to ..... c) Fluid velocity: Darcy's law, in general index form, is given by: vi = Kij.

  7. Ductile fracture modeling : theory, experimental investigation and numerical verification

    E-Print Network [OSTI]

    Xue, Liang, 1973-

    2007-01-01T23:59:59.000Z

    The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...

  8. Numerically Efficient Water Quality Modeling and Security Applications

    E-Print Network [OSTI]

    Mann, Angelica

    2013-02-04T23:59:59.000Z

    utilities protect the public against potential contamination events. The first component is a novel water quality modeling framework referred to as Merlion. The linear system describing contaminant spread through the network at the core of Merlion provides...

  9. Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits

    E-Print Network [OSTI]

    Stryk, Oskar von

    Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control model and the algorithm for evaluating the dynamics. The formulation of the optimal control problem

  10. Author's personal copy A new 3D numerical model of cosmogenic nuclide 10

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    Author's personal copy A new 3D numerical model of cosmogenic nuclide 10 Be production's atmosphere cosmogenic isotopes A new quantitative model of production of the cosmogenic isotope 10 solar energetic particle events. The model was tested against the results of direct measurements

  11. Numerical Experiments of Some Krylov Subspace Methods for Black Oil Model

    E-Print Network [OSTI]

    Lai, Choi-Hong

    Numerical Experiments of Some Krylov Subspace Methods for Black Oil Model Jianwen Cao #3; Choi of linear systems originated from the black oil model in oil reservoir simulation. There exists some Krylov subspace algorithms and pre- conditioning techniques for the black oil model as appeared in the literature

  12. Liquid phase oxidation kinetics of oil sands bitumen: Models for in situ combustion numerical simulators

    SciTech Connect (OSTI)

    Adegbesan, K.O.; Donnelly, J.K.; Moore, R.G.; Bennion, D.W.

    1986-08-01T23:59:59.000Z

    Multiresponse kinetic models are established for the low-temperature oxidation (LTO) reaction of Athabasca oil sands bitumen. The models provide adequate description of the overall rate of oxygen consumption and of the reactions of the liquid phase bitumen components. The LTO models are suitable for use in the in situ combustion numerical simulators of oil sands.

  13. A CONSISTENT MODELLING METHODOLOGY FOR SECONDARY1 SETTLING TANKS: A RELIABLE NUMERICAL METHOD2

    E-Print Network [OSTI]

    Brger, Raimund

    relations for hindered settling, compression and dispersion can be used within the model, allowing the user, continuous sedimentation, secondary clarifier, simulation5 model, partial differential equation6 NomenclatureA CONSISTENT MODELLING METHODOLOGY FOR SECONDARY1 SETTLING TANKS: A RELIABLE NUMERICAL METHOD2

  14. Foundation heat exchangers for residential ground source heat pump systems Numerical modeling and experimental validation

    SciTech Connect (OSTI)

    Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University

    2011-01-01T23:59:59.000Z

    A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

  15. IMPROVED NUMERICAL METHODS FOR MODELING RIVER-AQUIFER INTERACTION.

    SciTech Connect (OSTI)

    Tidwell, Vincent C.; Sue Tillery; Phillip King

    2008-09-01T23:59:59.000Z

    A new option for Local Time-Stepping (LTS) was developed to use in conjunction with the multiple-refined-area grid capability of the U.S. Geological Survey's (USGS) groundwater modeling program, MODFLOW-LGR (MF-LGR). The LTS option allows each local, refined-area grid to simulate multiple stress periods within each stress period of a coarser, regional grid. This option is an alternative to the current method of MF-LGR whereby the refined grids are required to have the same stress period and time-step structure as the coarse grid. The MF-LGR method for simulating multiple-refined grids essentially defines each grid as a complete model, then for each coarse grid time-step, iteratively runs each model until the head and flux changes at the interfacing boundaries of the models are less than some specified tolerances. Use of the LTS option is illustrated in two hypothetical test cases consisting of a dual well pumping system and a hydraulically connected stream-aquifer system, and one field application. Each of the hypothetical test cases was simulated with multiple scenarios including an LTS scenario, which combined a monthly stress period for a coarse grid model with a daily stress period for a refined grid model. The other scenarios simulated various combinations of grid spacing and temporal refinement using standard MODFLOW model constructs. The field application simulated an irrigated corridor along the Lower Rio Grande River in New Mexico, with refinement of a small agricultural area in the irrigated corridor.The results from the LTS scenarios for the hypothetical test cases closely replicated the results from the true scenarios in the refined areas of interest. The head errors of the LTS scenarios were much smaller than from the other scenarios in relation to the true solution, and the run times for the LTS models were three to six times faster than the true models for the dual well and stream-aquifer test cases, respectively. The results of the field application show that better estimates of daily stream leakage can be made with the LTS simulation, thereby improving the efficiency of daily operations for an agricultural irrigation system. ACKNOWLEDGEMENTSThe authors appreciatively acknowledge support for Sue Tillery provided by Sandia National Laboratories' through a Campus Executive Laboratory Directed Research and Development (LDRD) research project.Funding for this study was provided by Directed Research and Development (LDRD) research project.

  16. Numerical Integration Numerical Summation

    E-Print Network [OSTI]

    Cohen, Henri

    Numerical Integration Numerical Summation Numerical Extrapolation Numerical Recipes for Multiprecision Computations #12;Numerical Integration Numerical Summation Numerical Extrapolation Multiprecision, integration, summation, extrapolation, evaluation of continued fractions, Euler products and sums, complete

  17. Lattice Percolation Approach to Numerical Modeling of Tissue Aging

    E-Print Network [OSTI]

    Privman, Vladimir; Libert, Sergiy

    2015-01-01T23:59:59.000Z

    We describe a percolation-type approach to modeling of the processes of aging and certain other properties of tissues analyzed as systems consisting of interacting cells. Tissues are considered as structures made of regular healthy, senescent, dead (apoptotic) cells, and studied dynamically, with the ongoing processes including regular cell division to fill vacant sites left by dead cells, healthy cells becoming senescent or dying, and other processes. Statistical-mechanics description can provide patterns of time dependence and snapshots of morphological system properties. An illustrative application of the developed theoretical modeling approach is reported, confirming recent experimental findings that inhibition of senescence can lead to extended lifespan.

  18. EFFICIENT NUMERICAL SOLUTION TECHNIQUES IN COMPOSITION MODEL 1

    E-Print Network [OSTI]

    on the reservoir pressure and saturation pressure. A black­oil model works well in simulating the waterflooding The objective of reservoir simulation is to understand the complex chemical, physical, and fluid flow processes occurring in a petroleum reservoir sufficiently well to be able to optimize the recovery of hydrocarbon

  19. Joint physical and numerical modeling of water distribution networks.

    SciTech Connect (OSTI)

    Zimmerman, Adam; O'Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei

    2009-01-01T23:59:59.000Z

    This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.

  20. Numerical modeling of multi-GeV laser wakefield electron acceleration inside a dielectric capillary tube

    SciTech Connect (OSTI)

    Paradkar, B. S.; Cros, B.; Maynard, G. [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France); Mora, P. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)] [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2013-08-15T23:59:59.000Z

    Numerical modeling of laser wakefield electron acceleration inside a gas filled dielectric capillary tube is presented. Guiding of a short pulse laser inside a dielectric capillary tube over a long distance (?1 m) and acceleration of an externally injected electron bunch to ultra-relativistic energies (?5-10 GeV) are demonstrated in the quasi-linear regime of laser wakefield acceleration. Two dimensional axisymmetric simulations were performed with the code WAKE-EP (Extended Performances), which allows computationally efficient simulations of such long scale plasma. The code is an upgrade of the quasi-static particle code, WAKE [P. Mora and T. M. Antonsen, Jr., Phys. Plasmas 4, 217 (1997)], to simulate the acceleration of an externally injected electron bunch (including beam loading effect) and propagation of the laser beam inside a dielectric capillary. The influence of the transverse electric field of the plasma wake on the radial loss of the accelerated electrons to the dielectric wall is investigated. The stable acceleration of electrons to multi-GeV energy with a non-resonant laser pulse with a large spot-size is demonstrated.

  1. Numerical simulation of micro-fluidic passive and active mixers

    E-Print Network [OSTI]

    Kumar, Saurabh

    2002-01-01T23:59:59.000Z

    Numerical simulations of mixing using passive and active techniques are performed. For passive mixing, numerical modeling of a micro-fluidic device, build by Holden and Cremer, was performed. The micro-fluidic device consists of a Y...

  2. Numerical modeling and experimental measurements of water spray impact and transport over a cylinder.

    SciTech Connect (OSTI)

    Avedisian, C. T. (Cornell University, Ithaca, NY); Presser, Cary (National Institute of Standard & Technology, Gaithersburg, MD); DesJardin, Paul Edward (University at Buffalo, New York, NY); Hewson, John C.; Yoon, Sam Sukgoo

    2005-03-01T23:59:59.000Z

    This study compares experimental measurements and numerical simulations of liquid droplets over heated (to a near surface temperature of 423 K) and unheated cylinders. The numerical model is based on an unsteady Reynolds-averaged Navier-Stokes (RANS) formulation using a stochastic separated flow (SSF) approach for the droplets that includes submodels for droplet dispersion, heat and mass transfer, and impact on a solid surface. The details of the droplet impact model are presented and the model is used to simulate water spray impingement on a cylinder. Computational results are compared with experimental measurements using phase Doppler interferometry (PDI).

  3. Generation IV benchmarking of TRISO fuel performance models under accident conditions. Modeling input data

    SciTech Connect (OSTI)

    Blaise Collin

    2014-09-01T23:59:59.000Z

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read this document thoroughly to make sure all the data needed for their calculations is provided in the document. Missing data will be added to a revision of the document if necessary.

  4. A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Numerical Model for the Dynamic Simulation of a Recirculation Single- Effect Absorption Chiller A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film

  5. URBAN AEROSOLS SURVEY USING LIDAR AND NUMERICAL MODEL S. GEFFROY1

    E-Print Network [OSTI]

    Boyer, Edmond

    URBAN AEROSOLS SURVEY USING LIDAR AND NUMERICAL MODEL S. GEFFROY1 , L. SOULHAC2 , E. FREJAFON3 , R technologique ALATA BP2, F-60550 Verneuil-en-Halatte, France. Keywords: LIDAR, URBAN AEROSOLS, MODEL, IMPACT SURVEY. INTRODUCTION The impact of particulate matters and aerosols on environment and on radiative

  6. Numerical methods for vector Stefan models of solid-state alloys

    E-Print Network [OSTI]

    Vuik, Kees

    -called aluminium-based alloys. Subsequently, the obtained alloy is cast into a mould where it solidifies. DuringNumerical methods for vector Stefan models of solid-state alloys PROEFSCHRIFT ter verkrijging van for vector Stefan models of solid-state alloys. Dissertation at Delft University of Technology. Copyright c

  7. NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING

    E-Print Network [OSTI]

    Stewart, Sarah T.

    NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING H. A. Ai1 , T. J beneath impact crater in granite. Model constants are determined either directly from static uniaxial from Century Dynamics to simulate the shock-induced damage in granite targets impacted by projectiles

  8. An XFEM Model for Carbon Sequestration Journal: International Journal for Numerical Methods in Engineering

    E-Print Network [OSTI]

    Gracie, Robert

    PeerReview Only An XFEM Model for Carbon Sequestration Journal: International Journal for Numerical method, Carbon Sequestration, Multiphase flow, XFEM, Multifield systems, Petrov-Galerkin httpScience (www.interscience.wiley.com). DOI: 10.1002/nme An XFEM Model for Carbon Sequestration Chris Ladubec

  9. Controls on advance of tidewater glaciers: results from numerical modeling applied to Columbia Glacier

    E-Print Network [OSTI]

    Nick, F. M.; van der Veen, Cornelis J.; Oerlemans, J.

    2007-07-11T23:59:59.000Z

    A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance on land to the head...

  10. FOUNDATION, ANALYSIS, AND NUMERICAL INVESTIGATION OF A VARIATIONAL NETWORK-BASED MODEL FOR RUBBER

    E-Print Network [OSTI]

    Boyer, Edmond

    FOUNDATION, ANALYSIS, AND NUMERICAL INVESTIGATION OF A VARIATIONAL NETWORK-BASED MODEL FOR RUBBER, many models based on polymer chain statistics have been proposed to describe rubber elasticity. Recently, Alicandro, Cicalese, and the first author rigorously derived a continuum theory of rubber

  11. NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS

    E-Print Network [OSTI]

    processes. A black-oil model is commonly used to describe water injection. This model works well. Special focus is posed on the numerical solution algorithms for the saturation equation, which is a convection dominated, degenerate convection-di#11;usion equation. Both theory and applications are discussed

  12. A Model and Numerical Framework for the Simulation of Solid-Solid Phase Transformations

    E-Print Network [OSTI]

    Govindjee, Sanjay

    A Model and Numerical Framework for the Simulation of Solid-Solid Phase Transformations Garrett J computational realization for the simulation of solid-solid phase transformations of the type observed in shape physical experiments and is indicative of the power of the proposed modelling methodology. In particular

  13. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial

  14. MODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI-DATION OF CERAMIC COMPOSITES

    E-Print Network [OSTI]

    Adjerid, Slimane

    . INTRODUCTION Oxidation shortens the life of ceramic matrix composites by, e.g., chang- ing the elasticMODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI- DATION OF CERAMIC COMPOSITES S. Adjerid, M. Ai of thermal or other loading may expose the matrix and bers to hostile envi- ronments. We present a model

  15. Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics Hong Gun Sung½ and Stephan T. Grilli¾ ½ Korea Ocean Research and Development Institute, Daejeon model fully nonlinear free surface waves caused by a translating dis- turbance made of a pressure patch

  16. Concrete calcium leaching at variable temperature: experimental data and numerical model inverse

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , concrete porous solution is very basic (pH around 13) and several ionic species are highly concentrated [1Concrete calcium leaching at variable temperature: experimental data and numerical model inverse/DSU/SSIAD/BERIS, Fontenay-aux-Roses, France Abstract A simplified model for calcium leaching in concrete is presented

  17. Numerical modeling of response of monolithic and bilayer plates to impulsive loads

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    -receiving side) amplifies the initial shock loading and thereby enhances the destructive effect of the blast modeling FEM analysis Metal-elastomer adhesion Numerical blast modeling a b s t r a c t In this paper, we in the latter case the pressure effects. Comparing the simulation and the experimental results, we focus

  18. international journal of numerical modelling : electronic networks, devices and fields, Vol. 10, 217229 (1997)

    E-Print Network [OSTI]

    Bornemann, Jens

    , 217­229 (1997) SPECTRAL-DOMAIN MODELLING OF SUPERCONDUCTING MICROSTRIP STRUCTURES smain amari with available data to document the validity of the approach. © 1997 by John Wiley & Sons, Ltd. Int. J. Numer. Model., 10, 217­229 (1997) No. of Figures: 9. No. of Tables: 0. No. of References: 18. 1. INTRODUCTION

  19. Numerical comparison between relaxation and nonlinear equilibrium models. Application to chemical engineering.

    E-Print Network [OSTI]

    d'Orléans, Université

    processes widely used in chemical engineering: distillation and chromatography. Distillation is a wellNumerical comparison between relaxation and nonlinear equilibrium models. Application to chemical engineering. F. James 1 M. Postel 2 M. Sep'ulveda 3 Abstract A model to take into account the finite exchange

  20. Numerical modeling of fiber lasers with long and ultra-long ring cavity

    E-Print Network [OSTI]

    Turitsyn, Sergei K.

    Numerical modeling of fiber lasers with long and ultra-long ring cavity I.A. Yarutkina,1,2, O. S. Kobtsev, S. Kukarin, and Y. Fedotov, "Ultra-low repetition rate mode-locked fiber laser with high highlight two important aspects related to a mathematical modeling of pulsed fiber lasers with long

  1. A consistent modelling methodology for secondary settling tanks: a reliable numerical method

    E-Print Network [OSTI]

    Brger, Raimund

    accounting for sediment compressibility, and a dispersion term for turbulence. In addition, the solutionA consistent modelling methodology for secondary settling tanks: a reliable numerical method modelling methodology for secondary settling tanks (SSTs) leads to a partial differential equation (PDE

  2. On a test of the modified BCS theory performance in the picket fence model

    E-Print Network [OSTI]

    Nguyen Dinh Dang

    2009-04-03T23:59:59.000Z

    The errors in the arguments, numerical results, and conclusions in the paper "Test of a modified BCS theory performance in the picket fence model" [Nucl. Phys. A 822 (2009) 1] by V.Yu. Ponomarev and A.I. Vdovin are pointed out. Its repetitions of already published material are also discussed.

  3. Template-based hardware-software codesign for high-performance embedded numerical accelerators

    E-Print Network [OSTI]

    Sredojevi?, Ranko Radovin

    2013-01-01T23:59:59.000Z

    Sophisticated algorithms for control, state estimation and equalization have tremendous potential to improve performance and create new capabilities in embedded and mobile systems. Traditional implementation approaches are ...

  4. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

    E-Print Network [OSTI]

    Gustavsen Ph.D., Arild

    2010-01-01T23:59:59.000Z

    heat transfer performance in fenestration system based on finite element methods.finite -element method (FEM) was used to solve the conductive heat -transfer

  5. Uncertainty, Performance, and Model Dependency in Approximate Adaptive Nonlinear Control

    E-Print Network [OSTI]

    Szepesvari, Csaba

    Uncertainty, Performance, and Model Dependency in Approximate Adaptive Nonlinear Control M. French, and the performance of a class of approximate model based adaptive controllers is studied. An upper performance bound uncertainty model; control effort bounds require both L 2 and L 1 uncertainty models), and various structural

  6. Fast and accurate prediction of numerical relativity waveforms from binary black hole mergers using surrogate models

    E-Print Network [OSTI]

    Blackman, Jonathan; Galley, Chad R; Szilagyi, Bela; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A

    2015-01-01T23:59:59.000Z

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second dependin...

  7. Characterization of Texas lignite and numerical modeling of its in-situ gasification

    E-Print Network [OSTI]

    Wang, Yih-Jy

    1983-01-01T23:59:59.000Z

    Modeling Site selection for in-situ gasification projects normally involves application of site screen1ng criteria. Some of these cr1teria were discussed by Russell et al. (1983). Numerical simulation may play an important role in s1te selection...CHARACTERIZATION OF TEXAS LIGNITE AND NUMERICAL MODELING OF ITS IN-SITU GASIFICATION A Thesis by YIH-JY WANG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

  8. The numerical solution of a nickel-cadmium battery cell model using the method of lines

    E-Print Network [OSTI]

    Hailu, Teshome

    1990-01-01T23:59:59.000Z

    THE NUMERICAL SOLUTION OF A NICKEL-CADMIUM BATTERY CELL MODEL USING THE METHOD OF LINES A Thesis by TESHOME HAILU Submitted to the Office of Graduate Studies Texas Adi:M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1990 Major Subject: Chemical Engineering THE NUMERICAL SOLUTION OF A NICKEL-CADMIUM BATTERY CELL MODEL USING THE METHOD OF LINES A Thesis by TESHOME HAILU Approved as to style and content by: Ralph E. White (Chairman...

  9. Sandia Energy - PV Performance Modeling Collaborative's New and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling & Simulation Solar Newsletter Photovoltaic Systems Evaluation Laboratory (PSEL) PV Performance Modeling Collaborative's New and Improved Website Is Launched Previous Next...

  10. Proceedings of the Numerical Modeling for Underground Nuclear Test Monitoring Symposium

    SciTech Connect (OSTI)

    Taylor, S.R.; Kamm, J.R. [eds.

    1993-11-01T23:59:59.000Z

    The purpose of the meeting was to discuss the state-of-the-art in numerical simulations of nuclear explosion phenomenology with applications to test ban monitoring. We focused on the uniqueness of model fits to data, the measurement and characterization of material response models, advanced modeling techniques, and applications of modeling to monitoring problems. The second goal of the symposium was to establish a dialogue between seismologists and explosion-source code calculators. The meeting was divided into five main sessions: explosion source phenomenology, material response modeling, numerical simulations, the seismic source, and phenomenology from near source to far field. We feel the symposium reached many of its goals. Individual papers submitted at the conference are indexed separately on the data base.

  11. Design and Execution of Model Experiments to Validate Numerical Modelling of 2D Ship Operations in Pack Ice

    E-Print Network [OSTI]

    Bruneau, Steve

    in Pack Ice Roelof C. Dragt Offshore Engineering Faculty of Mechanical, Maritime and Material Engineering of experiments to validate a Graphics Processing Unit based numerical modelling of ship operations in 2D pack ice interaction, 2D Model Experiments, Image Processing. I. INTRODUCTION A ship travelling through pack ice

  12. The NINJA-2 project: Detecting and characterizing gravitational waveforms modelled using numerical binary black hole simulations

    E-Print Network [OSTI]

    :,; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ain, A; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Andersen, M; Anderson, R; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauchrowitz, J; Bauer, Th S; Behnke, B; Bejger, M; Beker, M G; Belczynski, C; Bell, A S; Bell, C; Bergmann, G; Bersanetti, D; Bertolini, A; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bloemen, S; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bosi, L; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brckner, F; Buchman, S; Bulik, T; Bulten, H J; Buonanno, A; Burman, R; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Bustillo, J Caldern; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavagli, M; Cavalier, F; Cavalieri, R; Celerier, C; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio, M; Conte, A; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corpuz, A; Corsi, A; Costa, C A; Coughlin, M W; Coughlin, S; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; Debreczeni, G; Degallaix, J; Delglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Daz, M; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Donath, A; Donovan, F; Dooley, K L; Doravari, S; Dossa, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H; Ehrens, P; Eichholz, J; Eikenberry, S S; Endr?czi, G; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fehrmann, H; Fejer, M M; Feldbaum, D; Feroz, F; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Gaonkar, S; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; Gonzlez, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goler, S; Gouaty, R; Grf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K; Gustafson, E K; Gustafson, R; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hart, M; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hooper, S; Hopkins, P; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jaranowski, P; Ji, Y; Jimnez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karlen, J; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawazoe, F; Kflian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N; Kim, N G; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I

    2014-01-01T23:59:59.000Z

    The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered w...

  13. Sandia National Laboratories: PV Reliability & Performance Model

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Generator Modeling Radar Friendly Blades Special Programs Techno-Economic Modeling, Analysis, and Support Analysis, Modeling, Cost of Energy, and Policy Impact: Wind Vision 2014...

  14. Low Temperature Performance: Performance Modeling | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetterEconomy andTerms LoanLosCombustion |NeedsPerformance:

  15. Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2

    E-Print Network [OSTI]

    Kirby, James T.

    Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2 , James T of Civil Engineering, University of Roma Tre Low-frequency hydro-acoustic waves are precursors of tsunamis. Detection of hydro-acoustic waves generated due to the water column compression triggered by sudden seabed

  16. January 2, 2008 Numerical modeling of the effect of carbon dioxide

    E-Print Network [OSTI]

    Boyer, Edmond

    January 2, 2008 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la dformation des calcaires par dissolution sous contrainte: rsultats;Abstract When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its

  17. Numerical Modelling of Unsaturated Flow in Uniform and Heterogeneous Waste Rock Piles

    E-Print Network [OSTI]

    Aubertin, Michel

    Numerical Modelling of Unsaturated Flow in Uniform and Heterogeneous Waste Rock Piles O Fala1 , M Aubertin1,3 , J Molson1 , B Bussire2,3 , G W Wilson4 , R Chapuis1 and V Martin1 ABSTRACT Waste rock piles these piles, many physical, geochemical and biological processes can contribute to the production of AMD

  18. Numerical methods for the simulation of a corrosion model in a nuclear waste deep repository $

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Numerical methods for the simulation of a corrosion model in a nuclear waste deep repository $ C of the French nuclear waste management agency ANDRA, investigations are conducted to optimize and finalize by the Nuclear Waste Management Agency ANDRA Corresponding author. Phone: +49 30 20372 560, Fax: +49 30 2044975

  19. Numerical analysis of electric field formulations of the eddy current model

    E-Print Network [OSTI]

    Rodríguez, Rodolfo

    Numerical analysis of electric field formulations of the eddy current model Alfredo Berm´udez1 methods for the numeri- cal solution of the eddy current problem in a bounded conducting domain crossed): 78M10, 65N30 Key words Low-frequency harmonic Maxwell equations, eddy currents, finite elements

  20. Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model

    E-Print Network [OSTI]

    Rodríguez, Rodolfo

    Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model the theoretically predicted behavior of the method, are reported. Keywords transient eddy current · axisymmetric is the accurate computation of power losses in the ferromagnetic components of the core due to hysteresis and eddy-current

  1. NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON-LOCAL

    E-Print Network [OSTI]

    Rodríguez, Rodolfo

    NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON@ing-mat.udec.cl This paper deals with an axisymmetric transient eddy current problem in conductive nonlinear magnetic media of the proposed scheme. Keywords: transient eddy current problem; electromagnetic losses; nonlinear magnetic

  2. A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness

    E-Print Network [OSTI]

    Nagy, Peter B.

    A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation, the path of the eddy current must follow a more tortuous route in the material, which produces a reduction

  3. Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting

    E-Print Network [OSTI]

    Ribes, Aurlien

    Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting SAMUEL RE significant. This led to the implementation of an ensemble Kalman filter (EnKF) within COBEL-ISBA. The new by using an ensemble Kalman filter (EnKF; Evensen 1994, 2003). Theoreti- cally, ensemble filters

  4. LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY CONVERTERS

    E-Print Network [OSTI]

    Haller, Merrick

    1 LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY of wave energy converters (WECs) on water waves through the analysis of extensive laboratory experiments absorption is a reasonable predictor of the effect of WECs on the far field. Keywords: wave- energy; spectral

  5. A numerical modeling study on desert oasis self-supporting mechanisms

    E-Print Network [OSTI]

    Chu, Peter C.

    A numerical modeling study on desert oasis self-supporting mechanisms Peter C. Chua, *, Shihua Lub February 2005 Abstract Oasis self-supporting mechanisms due to oasis breeze circulation (OBC) are proposed from the oasis makes the oasis surface colder than the surrounding desert surface. The sensible heat

  6. September 25, 2006 Numerical modeling of the effect of carbon dioxide

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    September 25, 2006 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la dformation des calcaires par dissolution sous contrainte: rsultats@obs.ujf- grenoble.fr, marielle.collombet@ujf-grenoble.fr, yleguen@lgit.obs.ujf-grenoble.fr. #12;Abstract When carbon

  7. COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS

    E-Print Network [OSTI]

    Dimov, Ivan

    COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS I. DIMOV , K. GEORGIEVy, TZ. OSTROMSKY , R. J. VAN DER PASz, AND Z. ZLATEVx Abstract. The air pollution, and especially the reduction of the air pollution to some acceptable levels, is an important environmental problem, which

  8. Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters

    E-Print Network [OSTI]

    ) and pressure (15 MPa) of hot steam [2]. Some units are made of cheap corrosion and heat-resistant steel which1 Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters]. Power-generating units of TPP operate under severe corrosive conditions: high temperature (515 - 530C

  9. NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING

    E-Print Network [OSTI]

    Boyer, Edmond

    NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING P. Mondaleka , L'Etudes Structurales), France c Universit Paul Sabatier, Toulouse, France Abstract. Spark Plasma Sintering belongs: Finite element method, Spark plasma sintering, powder compaction. INTRODUCTION Spark Plasma Sintering

  10. A numerical ocean circulation model of the Norwegian and Greenland Seas

    E-Print Network [OSTI]

    Stevens, David

    A numerical ocean circulation model of the Norwegian and Greenland Seas DAVID P STEVENS School of the Norwegian and Greenland Seas are investigated using a three-dimensional primitive equation ocean circulation and seasonally varying wind and thermohalme forcing. The connections of the Norwegian and Greenland Seas

  11. Numerical Solution of Two Asset Jump Diffusion Models for Option Valuation

    E-Print Network [OSTI]

    Forsyth, Peter A.

    Numerical Solution of Two Asset Jump Diffusion Models for Option Valuation Simon S. Clift and Peter parabolic partial integro-differential equation (PIDE). An implicit, finite difference method is derived with an FFT. The method prices both American and European style contracts indepen- dent (under some simple

  12. A LARGE SCALE CONTINUUM-DISCRETE NUMERICAL MODELLING: APPLICATION TO OVERBURDEN DAMAGE OF A SALT CAVERN

    E-Print Network [OSTI]

    Boyer, Edmond

    A LARGE SCALE CONTINUUM-DISCRETE NUMERICAL MODELLING: APPLICATION TO OVERBURDEN DAMAGE OF A SALT damage on top of an underground solution mining, an in-situ experiment is undertaken above a salt cavity in the Lorraine region (NE of France). The overburden overlying the salt cavity is characterized by a competent

  13. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

  14. Numerical modeling of spray cooling-assisted dermatologic laser surgery for treatment of port wine stains

    E-Print Network [OSTI]

    Aguilar, Guillermo

    Numerical modeling of spray cooling-assisted dermatologic laser surgery for treatment of port wine to the epidermis during dermatologic laser surgery (DLS) for removal of port wine stain (PWS) birthmarks heat (J/kg/K) c speed of light in i (m/s) D optical diffusion coefficient (m) Ea activation energy

  15. 3 Response to comment by Jozsef Szilagyi on 4 ``Using numerical modelling to evaluate the

    E-Print Network [OSTI]

    McDonnell, Jeffrey J.

    REPLY 3 Response to comment by Jozsef Szilagyi on 4 ``Using numerical modelling to evaluate the 5 by Szilagyi is a welcome addition to the de- 15 bate surrounding the link between the hypothesis of 16 a possible explanation for high proportions of 40pre-event water. 41Szilagyi (submitted) has identified

  16. Numerical modelling of avalanches based on Saint-Venant equations using a kinetic scheme

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    avalanches are treated here as a dry granular flow with Coulomb-type behavior. The numerical finite volume of an avalanche over simplified topography. Coulomb-type behavior with constant and variable friction angle modelling, Coulomb friction, Saint-Venant equations, finite volume kinetic scheme. 1 Introduction Granular

  17. NUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA-HIGH

    E-Print Network [OSTI]

    Boyer, Edmond

    in the cementitious matrix can react with carbon dioxide dissolved in the water filling the crack. Autogenous healingNUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA into the crack and leads to a partial recovery of mechanical properties (Young's modulus, tensile strength

  18. Mathematical, physical and numerical principles essential for models of turbulent mixing

    SciTech Connect (OSTI)

    Sharp, David Howland [Los Alamos National Laboratory; Lim, Hyunkyung [STONY BROOK UNIV; Yu, Yan [STONY BROOK UNIV; Glimm, James G [STONY BROOK UNIV

    2009-01-01T23:59:59.000Z

    We propose mathematical, physical and numerical principles which are important for the modeling of turbulent mixing, especially the classical and well studied Rayleigh-Taylor and Richtmyer-Meshkov instabilities which involve acceleration driven mixing of a fluid discontinuity layer, by a steady accerleration or an impulsive force.

  19. 792 / JOURNAL OF ENVIRONMENTAL ENGINEERING / SEPTEMBER 1999 NUMERICAL MODEL OF SEDIMENTATION/THICKENING

    E-Print Network [OSTI]

    Wells, Scott A.

    792 / JOURNAL OF ENVIRONMENTAL ENGINEERING / SEPTEMBER 1999 NUMERICAL MODEL OF SEDIMENTATION with the ASCE Manager of Journals. The manuscript for this paper was submitted for review and possible publication on July 20, 1998. This paper is part of the Journal of Environmental Engineering, Vol. 125, No. 9

  20. The Hamiltonian Particle-Mesh (HPM) method for numerical modeling of atmospheric flows.

    E-Print Network [OSTI]

    Kim, Guebuem

    The Hamiltonian Particle-Mesh (HPM) method for numerical modeling of atmospheric flows. Seoleun Shin 15. Feb. 2011 Abstract The Hamiltonian Particle-Mesh (HPM) method is an interesting alternative have developed schemes based on the HPM method for the shallow-water equations on the sphere, nonhydro

  1. Numerical Simulation of Thermal Performance of Floor Radiant Heating System with Enclosed Phase Change Material

    E-Print Network [OSTI]

    Qiu, L.; Wu, X.

    2006-01-01T23:59:59.000Z

    In the present paper, a kind of enclosed phase change material (PCM) used in solar and low-temperature hot water radiant floor heating is investigated. On the basis of obtaining the best performance of PCM properties, a new radiant heating structure...

  2. NUMERICAL VERIFICATION OF THE RELAP-7 CORE CHANNEL SINGLE-PHASE MODEL

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang; Richard Martineau

    2014-06-01T23:59:59.000Z

    The RELAP-7 code is the next generation of nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). All the physics in RELAP-7 are fully coupled and the errors resulted from the traditional operator-splitting approach are eliminated. By using 2nd order methods in both time and space and eliminating operator-splitting errors, the numerical error of RELAP-7 can be minimized. Numerical verification is the process to verify the orders of numerical methods. It is an important part of modern verification and validation process. The core channel component in RELAP-7 is designed to simulate coolant flow as well as the conjugated heat transfer between coolant flow and the fuel rod. A special treatment at fuel centerline to avoid numerical singularity for the cylindrical heat conduction in the continuous finite element mesh is discussed. One steady state test case and one fast power up transient test case are utilized for the verification of the core channel model with single-phase flow. Analytical solution for the fuel pin temperature and figures of merit such as peak clad temperature and peak fuel temperature are used to define numerical errors. These cases prove that the mass and energy are well conserved and 2nd order convergence rates for both time and space are achieved in the core channel model.

  3. Supercomputer and cluster performance modeling and analysis efforts:2004-2006.

    SciTech Connect (OSTI)

    Sturtevant, Judith E.; Ganti, Anand; Meyer, Harold (Hal) Edward; Stevenson, Joel O.; Benner, Robert E., Jr. (.,; .); Goudy, Susan Phelps; Doerfler, Douglas W.; Domino, Stefan Paul; Taylor, Mark A.; Malins, Robert Joseph; Scott, Ryan T.; Barnette, Daniel Wayne; Rajan, Mahesh; Ang, James Alfred; Black, Amalia Rebecca; Laub, Thomas William; Vaughan, Courtenay Thomas; Franke, Brian Claude

    2007-02-01T23:59:59.000Z

    This report describes efforts by the Performance Modeling and Analysis Team to investigate performance characteristics of Sandia's engineering and scientific applications on the ASC capability and advanced architecture supercomputers, and Sandia's capacity Linux clusters. Efforts to model various aspects of these computers are also discussed. The goals of these efforts are to quantify and compare Sandia's supercomputer and cluster performance characteristics; to reveal strengths and weaknesses in such systems; and to predict performance characteristics of, and provide guidelines for, future acquisitions and follow-on systems. Described herein are the results obtained from running benchmarks and applications to extract performance characteristics and comparisons, as well as modeling efforts, obtained during the time period 2004-2006. The format of the report, with hypertext links to numerous additional documents, purposefully minimizes the document size needed to disseminate the extensive results from our research.

  4. Direct Numerical Simulations of the Kraichnan Model: Scaling Exponents and Fusion Rules

    E-Print Network [OSTI]

    Adrienne L. Fairhall; Barak Galanti; Victor S. L'vov; Itamar Procaccia

    1997-07-01T23:59:59.000Z

    We present results from direct numerical simulations of the Kraichnan model for passive scalar advection by a rapidly-varying random scaling velocity field for intermediate values of the velocity scaling exponent. These results are compared with the scaling exponents predicted for this model by Kraichnan. Further, we test the recently proposed fusion rules which govern the scaling properties of multi-point correlations, and present results on the linearity of the conditional statistics of the Laplacian operator on the scalar field.

  5. Modelling and Numerical Simulation of Gas Migration in a Nuclear Waste Repository

    E-Print Network [OSTI]

    Bourgeat, Alain; Smai, Farid

    2010-01-01T23:59:59.000Z

    We present a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological radioactive waste repository. This model includes capillary effects and the gas diffusivity. The choice of the main variables in this model, Total or Dissolved Hydrogen Mass Concentration and Liquid Pressure, leads to a unique and consistent formulation of the gas phase appearance and disappearance. After introducing this model, we show computational evidences of its adequacy to simulate gas phase appearance and disappearance in different situations typical of underground radioactive waste repository.

  6. Performance deterioration modeling in aircraft gas turbine engines

    SciTech Connect (OSTI)

    Zaita, A.V. [Advanced Engineering and Research Associates, Inc., Arlington, VA (United States). Technology Development Div.; Buley, G. [Naval Surface Warfare Center, West Bethesda, MD (United States). Carderock Div.; Karlsons, G. [Naval Air Warfare Center, Patuxent River, MD (United States)

    1998-04-01T23:59:59.000Z

    Steady-state performance models can be used to evaluate a new engine`s baseline performance. As a gas turbine accumulates operating time in the field, its performance deteriorates due to fouling, erosion, and wear. This paper presents the development of a model for predicting the performance deterioration of aircraft gas turbines. The model accounts for rotating component deterioration based on the aircraft mission profiles and environmental conditions and the engine`s physical and design characteristics. The methodology uses data correlations combined with a stage stacking technique for the compressor and a tip rub model, along with data correlations for the turbine to determine the amount of performance deterioration. The performance deterioration model interfaces with the manufacturer`s baseline engine simulation model in order to create a deteriorated performance model for that engine.

  7. System Identification and Modelling of a High Performance Hydraulic Actuator

    E-Print Network [OSTI]

    Hayward, Vincent

    System Identification and Modelling of a High Performance Hydraulic Actuator Benoit Boulet, Laeeque with the experimental identification and modelling of the nonlinear dynamics ofa high performance hydraulic actuator. The actuator properties and performance are also discussed. 1 Introduction Hydraulic actuation used to be

  8. Applying High Performance Computing to Analyzing by Probabilistic Model Checking

    E-Print Network [OSTI]

    Schneider, Carsten

    Applying High Performance Computing to Analyzing by Probabilistic Model Checking Mobile Cellular on the use of high performance computing in order to analyze with the proba- bilistic model checker PRISM. The Figure Generation Script 22 2 #12;1. Introduction We report in this paper on the use of high performance

  9. Qualification of the ITER CS Quench Detection System using Numerical Modeling

    SciTech Connect (OSTI)

    Martovetsky, Nicolai N [ORNL; Radovinsky, Alexey L [ORNL

    2013-01-01T23:59:59.000Z

    Abstract The ITER Central Solenoid (CS) magnet needs to be protected against overheating of the conductor in the event of the occurrence of a normal zone (NZ). Due to a large amount of stored energy and slow NZ propagation, the NZ needs to be detected and the switchyard needs to open the breakers within 2 s after detection of the NZ. The CS will be discharged on a dump resistor with a time constant of 7.5 s. During operation of the CS and its interaction with the poloidal field (PF) coils and plasma current, the CS experiences large inductive voltages from multiple sources, including nonlinear signals from eddy currents in the vacuum vessel and plasma current variation, that make the task of detecting the resistive signal even more difficult. This inductive voltage needs to be cancelled by quench detection (QD) hardware (e.g., bridges, converters, filters, processors) and appropriate processing of the QD signals to reliably detect NZ initiation and propagation. Two redundant schemes are proposed as the baseline for the CS QD System: 1) A scheme with Regular Voltage Taps (RVT) from triads of Double Pancakes (DP) supplemented by Central Difference Averaging (CDA) and by digital suppression of the inductive voltage from all active coils (the CS and PF coils). Voltage taps are taken from helium outlets at the CS outer diameter. 2)A scheme with Cowound Voltage Taps (CVT) taken from cowound wires routed from the helium inlet at the CS inner diameter. Summary of results of the numerical modeling of the performance of both baseline CS QD systems is presented in this paper. Index Terms Quench detection, Central Solenoid, ITER

  10. Numerical upscaling for the eddy-current model with stochastic magnetic materials

    SciTech Connect (OSTI)

    Eberhard, Jens P. [Computer Simulation Technology, Bad Nauheimer Strasse, 19, D-64289 Darmstadt (Germany)], E-mail: jens.eberhard@cst.com; Popovic, Dan [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: dan.popovic@stud.uni-heidelberg.de; Wittum, Gabriel [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: wittum@uni-hd.de

    2008-04-01T23:59:59.000Z

    This paper deals with the upscaling of the time-harmonic Maxwell equations for heterogeneous media. We analyze the eddy-current approximation of Maxwell's equations to describe the electric field for heterogeneous, isotropic magnetic materials. The magnetic permeability of the materials is assumed to have random heterogeneities described by a Gaussian random field. We apply the so-called Coarse Graining method to develop a numerical upscaling of the eddy-current model. The upscaling uses filtering and averaging procedures in Fourier space which results in a formulation of the eddy-current model on coarser resolution scales where the influence of sub-scale fluctuations is modeled by effective scale- and space-dependent reluctivity tensors. The effective reluctivity tensors can be obtained by solving local partial differential equations which contain a Laplacian as well as a curl-curl operator. We present a computational method how the equation of the combined operators can be discretized and solved numerically using an extended variational formulation compared to standard discretizations. We compare the results of the numerical upscaling of the eddy-current model with theoretical results of Eberhard [J.P. Eberhard, Upscaling for the time-harmonic Maxwell equations with heterogeneous magnetic materials, Physical Review E 72 (3), (2005)] and obtain a very good agreement.

  11. Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney

    E-Print Network [OSTI]

    1 Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney@usc.edu Colloquium topic area: 12. New Technology Concepts Keywords: Micro-combustion, Heat-recirculating combustors, Extinction limits Shortened running title: Numerical Modeling of Heat-Recirculating Combustors Word count

  12. Modeling well performance in compartmentalized gas reservoirs

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2008-10-10T23:59:59.000Z

    for consolidated reservoir cases while synthetic data (generated by the model using known parameters) was used for unconsolidated reservoir cases. In both cases, the Compartmentalized Depletion Model was used to analyze data, and estimate the OGIP and Jg of each...

  13. Modeling well performance in compartmentalized gas reservoirs

    E-Print Network [OSTI]

    Yusuf, Nurudeen

    2009-05-15T23:59:59.000Z

    for consolidated reservoir cases while synthetic data (generated by the model using known parameters) was used for unconsolidated reservoir cases. In both cases, the Compartmentalized Depletion Model was used to analyze data, and estimate the OGIP and Jg of each...

  14. Physical Modeling of the Motions of a Container Ship Moored to a Dock with Comparison to Numerical Simulation

    E-Print Network [OSTI]

    Zhi, Yuanzhe

    2013-07-11T23:59:59.000Z

    model experimental results of solid dock are also compared with the numerical simulation. These comparisons indicate that the motion characteristics of the model container ship represent similar trends for both rotations and translations...

  15. Degradation Pathway Models for Photovoltaics Module Lifetime Performance

    E-Print Network [OSTI]

    Rollins, Andrew M.

    Degradation Pathway Models for Photovoltaics Module Lifetime Performance Nicholas R. Wheeler, Laura data from Underwriter Labs, featuring measurements taken on 18 identical photovoltaic (PV) modules in modules and their effects on module performance over lifetime. Index Terms--photovoltaics, statistical

  16. Electrical, Frequency and Thermal Measurement and Modelling of Supercapacitor Performance

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Electrical, Frequency and Thermal Measurement and Modelling of Supercapacitor Performance Yasser--This paper presents an evaluation of commercial supercapacitors performance (ESR, C, self-discharge, Pmax, Emax, coulumbic efficiency, etc), under different conditions. Characterization of supercapacitor

  17. Hybrid Model of Existing Buildings for Transient Thermal Performance Estimation

    E-Print Network [OSTI]

    Xu, X.; Wang, S.

    2006-01-01T23:59:59.000Z

    Building level energy models are important to provide accurate prediction of energy consumption for building performance diagnosis and energy efficiency assessment of retrofitting alternatives for building performance upgrading. Simplified...

  18. Fast and accurate prediction of numerical relativity waveforms from binary black hole mergers using surrogate models

    E-Print Network [OSTI]

    Jonathan Blackman; Scott E. Field; Chad R. Galley; Bela Szilagyi; Mark A. Scheel; Manuel Tiglio; Daniel A. Hemberger

    2015-02-26T23:59:59.000Z

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second depending on the number of output modes and the sampling rate. Our model includes all spherical-harmonic ${}_{-2}Y_{\\ell m}$ waveform modes that can be resolved by the NR code up to $\\ell=8$, including modes that are typically difficult to model with other approaches. We assess the model's uncertainty, which could be useful in parameter estimation studies seeking to incorporate model error. We anticipate NR surrogate models to be useful for rapid NR waveform generation in multiple-query applications like parameter estimation, template bank construction, and testing the fidelity of other waveform models.

  19. Motivation Literature Network Performance Measure Network Robustness SCN Model Fin. Net. Model Conclusions Network Efficiency/Performance Measurement

    E-Print Network [OSTI]

    Nagurney, Anna

    Conclusions Network Efficiency/Performance Measurement with Vulnerability and Robustness Analysis Conclusions 1 Motivation 2 Literature Review 3 Network Efficiency/Performance Measure Variational Inequality Robustness SCN Model Fin. Net. Model Conclusions 1 Motivation 2 Literature Review 3 Network Efficiency/Performance

  20. Numerical-Model Investigation of the Hydrothermal Regime of a Straight-Through Shallow Cooling Pond

    SciTech Connect (OSTI)

    Sokolov, A. S. [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)] [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)

    2013-11-15T23:59:59.000Z

    A mathematic model based on solution of hydrodynamics and heat-transfer equations by the finite-element method is constructed to predict the hydrothermal regime of a straight-through shallow cooling pond, which provides cooling circulating water to a repository of spent nuclear fuel. Numerical experiments made it possible to evaluate the influence exerted by wind conditions and flow rate of water in the river on the temperature of the circulating water.

  1. An investigation of analytical and numerical sucker rod pumping mathematical models

    E-Print Network [OSTI]

    Schafer, Donald Joseph

    1987-01-01T23:59:59.000Z

    of MASTER OF SCIENCE May 1987 Major Subject: Petroleum Engineering AN INVESTIGATION OF ANALYTICAL AND NUMERICAL SUCKER ROD PUMPING MATHEMATICAL MODELS A Thesis by DONALD JOSEPH SCHAFER Approved as to style and content by: 7d JW. J ni (Chai... to Sucker Rod Pumping Research, Inc. , developed a method for computing downhole forces and displacements using an analog computer simulation. The procedure that results from this work, commonly called the API method, considers the total sucker rod...

  2. Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers

    E-Print Network [OSTI]

    Muraya, Norman K.

    1994-01-01T23:59:59.000Z

    Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed...

  3. Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers

    E-Print Network [OSTI]

    Muraya, Norman K.

    Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed...

  4. Numerical and analytical modeling of heat transfer between fluid and fractured rocks

    E-Print Network [OSTI]

    Li, Wei, S.M. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...

  5. Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    or radioactive waste [30], geothermal Corresponding author Email address: benoit.carrier@enpc.fr (Benoit Carrier processes. During the last sixty years, numerous papers [3, 7, 14, 21, 35, 34, 41, 25, 27, 22, 38, 36, 1. In the recent years, a scaling and asymptotic framework was built to determine the influence of the physical

  6. Detailed Performance Model for Photovoltaic Systems: Preprint

    SciTech Connect (OSTI)

    Tian, H.; Mancilla-David, F.; Ellis, K.; Muljadi, E.; Jenkins, P.

    2012-07-01T23:59:59.000Z

    This paper presents a modified current-voltage relationship for the single diode model. The single-diode model has been derived from the well-known equivalent circuit for a single photovoltaic cell. The modification presented in this paper accounts for both parallel and series connections in an array.

  7. Thermo--inertial bouncing of a relativistic collapsing sphere: A numerical model

    E-Print Network [OSTI]

    L. Herrera; A. Di Prisco; W. Barreto

    2005-12-05T23:59:59.000Z

    We present a numerical model of a collapsing radiating sphere, whose boundary surface undergoes bouncing due to a decreasing of its inertial mass density (and, as expected from the equivalence principle, also of the ``gravitational'' force term) produced by the ``inertial'' term of the transport equation. This model exhibits for the first time the consequences of such an effect, and shows that under physically reasonable conditions this decreasing of the gravitational term in the dynamic equation may be large enough as to revert the collapse and produce a bouncing of the boundary surface of the sphere.

  8. Moist processes and the quasi-hydrostatic approximation in a mesoscale numerical model

    E-Print Network [OSTI]

    Kennedy, Charles Joseph

    1987-01-01T23:59:59.000Z

    of Committee) James P. McGuirk (Member) J'ohn M. Klinck (Member) James R. Sco ns (Head of Department) December 1987 ABSTRACT Moist Processes and the Ouasi-Hydrostatic Approximation in a Mesoscale Numerical Model. (December 1987) Charles Joseph...HV)ds' ? gHp s + gHps a dg 1 gt = (gt), s 1 1 (19) the pressure tendency at the model top equation: g f V ~ (pHV)ds' ? VS Vp Q ( el 1 + 0 Yp CpT ? V (H0) ds' )' ? ) (20) Richardson's equation for vertical motion: s f , , f Id d'D &DDVdd ' ? 0 D, 0...

  9. On the formulation, parameter identification and numerical integration of the EMMI model :plasticity and isotropic damage.

    SciTech Connect (OSTI)

    Bammann, Douglas J.; Johnson, G. C. (University of California, Berkeley, CA); Marin, Esteban B.; Regueiro, Richard A. (University of Colorado, Boulder, CO)

    2006-01-01T23:59:59.000Z

    In this report we present the formulation of the physically-based Evolving Microstructural Model of Inelasticity (EMMI) . The specific version of the model treated here describes the plasticity and isotropic damage of metals as being currently applied to model the ductile failure process in structural components of the W80 program . The formulation of the EMMI constitutive equations is framed in the context of the large deformation kinematics of solids and the thermodynamics of internal state variables . This formulation is focused first on developing the plasticity equations in both the relaxed (unloaded) and current configurations. The equations in the current configuration, expressed in non-dimensional form, are used to devise the identification procedure for the plasticity parameters. The model is then extended to include a porosity-based isotropic damage state variable to describe the progressive deterioration of the strength and mechanical properties of metals induced by deformation . The numerical treatment of these coupled plasticity-damage constitutive equations is explained in detail. A number of examples are solved to validate the numerical implementation of the model.

  10. Application Insight Through Performance Modeling Gabriel Marin

    E-Print Network [OSTI]

    Marin, Gabriel

    that estimate the maximum gain expected from tuning different parts of an application, or from increasing the number of machine resources. We show how this metric helped iden- tify a bottleneck in the ASCI Sweep3D benchmark where the lack of instruction-level parallelism limited performance. Transforming one frequently

  11. Probe measurements and numerical model predictions of evolving size distributions in premixed flames

    SciTech Connect (OSTI)

    De Filippo, A.; Sgro, L.A.; Lanzuolo, G.; D'Alessio, A. [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli (Italy)

    2009-09-15T23:59:59.000Z

    Particle size distributions (PSDs), measured with a dilution probe and a Differential Mobility Analyzer (DMA), and numerical predictions of these PSDs, based on a model that includes only coagulation or alternatively inception and coagulation, are compared to investigate particle growth processes and possible sampling artifacts in the post-flame region of a C/O = 0.65 premixed laminar ethylene-air flame. Inputs to the numerical model are the PSD measured early in the flame (the initial condition for the aerosol population) and the temperature profile measured along the flame's axial centerline. The measured PSDs are initially unimodal, with a modal mobility diameter of 2.2 nm, and become bimodal later in the post-flame region. The smaller mode is best predicted with a size-dependent coagulation model, which allows some fraction of the smallest particles to escape collisions without resulting in coalescence or coagulation through the size-dependent coagulation efficiency ({gamma}{sub SD}). Instead, when {gamma} = 1 and the coagulation rate is equal to the collision rate for all particles regardless of their size, the coagulation model significantly under predicts the number concentration of both modes and over predicts the size of the largest particles in the distribution compared to the measured size distributions at various heights above the burner. The coagulation ({gamma}{sub SD}) model alone is unable to reproduce well the larger particle mode (mode II). Combining persistent nucleation with size-dependent coagulation brings the predicted PSDs to within experimental error of the measurements, which seems to suggest that surface growth processes are relatively insignificant in these flames. Shifting measured PSDs a few mm closer to the burner surface, generally adopted to correct for probe perturbations, does not produce a better matching between the experimental and the numerical results. (author)

  12. Summary of First PV Performance Modeling Workshop

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AnalystsOther Steve Ransome Navigant SolarTech Modelers CEC-UW Clean Power King Solar Works PVDesign Pro - Hoes Engineering PV*Sol PVSyst Universities U of Arizona U of...

  13. A Variable Cell Model for Simulating Gas Condensate Reservoir Performance

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    maturation profiles, which ie exhibitpd when gas pressure. Between this region near tha wellbore, SPE-~~~ SPE 21428 A Variable Cell Model for Simulating Gas Condensate Reservoir Performance A of depletion performance of gas condensate reservoirs report the existence of a A variable cell model

  14. Symposium on Human Performance Modeling Wayne D. Gray (Organizer)

    E-Print Network [OSTI]

    Gray, Wayne

    Laboratory Abstract This symposium is co-sponsored by the Human Performance Modeling Technical Group (HPM to the human factors community. For the Panel Dis- cussion, three additional members of the HPM-TG joined The Human Performance Modeling Technical Group (HPM-TG) of the Human Factors and Ergonomics Society (HFES

  15. Performance Modeling of Shared Memory Programsof SharedMemory Programs

    E-Print Network [OSTI]

    Teo, Yong-Meng

    nus edu sg/~teoymURL: www.comp.nus.edu.sg/ teoym 7th Workshop on High Performance Computing UPM Analysis l i l d l Analytical Model Summary 1 November 2011 47th Workshop on High Performance Computing November 2011 57th Workshop on High Performance Computing (invited talk) #12;R l t d W kRelated Work

  16. A localised subgrid scale model for fluid dynamical simulations in astrophysics I: Theory and numerical tests

    E-Print Network [OSTI]

    W. Schmidt; J. C. Niemeyer; W. Hillebrandt

    2006-01-23T23:59:59.000Z

    We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the subgrid scale model in this paper as a basis for more advanced applications in numerical simulations of complex astrophysical phenomena involving turbulence.

  17. An Investigation into Satellite Drag Modeling Performance

    E-Print Network [OSTI]

    Mance, Stephen

    2010-03-23T23:59:59.000Z

    . ................................................. 156 Figure 5.46 1995 GFZ-1 SLR RMS of Fit with F10.7. ............................................ 156 Figure 5.47 1996 GFZ-1 SLR RMS of Fit with Ap. ................................................. 157 Figure 5.48 1996 GFZ-1 SLR RMS of Fit with F.... Advances in conservative force modeling have shifted the majority of error in OD to the non-conservative forces such as drag, SRP, and Earth albedo. With refined 7 gravity models, drag becomes one of the largest sources of error for LEO regimes at lower...

  18. Developing an Energy Performance Modeling Startup Kit

    SciTech Connect (OSTI)

    Wood, A.

    2012-10-01T23:59:59.000Z

    In 2011, the NAHB Research Center began the first part of the multi-year effort by assessing the needs and motivations of residential remodelers regarding energy performance remodeling. The scope is multifaceted - all perspectives will be sought related to remodeling firms ranging in size from small-scale, sole proprietor to national. This will allow the Research Center to gain a deeper understanding of the remodeling and energy retrofit business and the needs of contractors when offering energy upgrade services. To determine the gaps and the motivation for energy performance remodeling, the NAHB Research Center conducted (1) an initial series of focus groups with remodelers at the 2011 International Builders' Show, (2) a second series of focus groups with remodelers at the NAHB Research Center in conjunction with the NAHB Spring Board meeting in DC, and (3) quantitative market research with remodelers based on the findings from the focus groups. The goal was threefold, to: Understand the current remodeling industry and the role of energy efficiency; Identify the gaps and barriers to adding energy efficiency into remodeling; and Quantify and prioritize the support needs of professional remodelers to increase sales and projects involving improving home energy efficiency. This report outlines all three of these tasks with remodelers.

  19. Cost and Performance Assumptions for Modeling Electricity Generation Technologies

    SciTech Connect (OSTI)

    Tidball, R.; Bluestein, J.; Rodriguez, N.; Knoke, S.

    2010-11-01T23:59:59.000Z

    The goal of this project was to compare and contrast utility scale power plant characteristics used in data sets that support energy market models. Characteristics include both technology cost and technology performance projections to the year 2050. Cost parameters include installed capital costs and operation and maintenance (O&M) costs. Performance parameters include plant size, heat rate, capacity factor or availability factor, and plant lifetime. Conventional, renewable, and emerging electricity generating technologies were considered. Six data sets, each associated with a different model, were selected. Two of the data sets represent modeled results, not direct model inputs. These two data sets include cost and performance improvements that result from increased deployment as well as resulting capacity factors estimated from particular model runs; other data sets represent model input data. For the technologies contained in each data set, the levelized cost of energy (LCOE) was also evaluated, according to published cost, performance, and fuel assumptions.

  20. Emissions of volatile organic compounds from stationary combustion sources: Numerical modeling capabilities

    SciTech Connect (OSTI)

    Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Kee, R.J.; Lutz, A.J. [Sandia National Labs., Albuquerque, NM (United States); Pitz, W.J.; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States); Senkan, S. [California Univ., Los Angeles, CA (United States)

    1992-09-01T23:59:59.000Z

    A collaborative research program initiated to study the emissions of a wide variety of chemical species from stationary combustion systems. These product species have been included in the Clean Air act legislation and their emissions must be rigidly controlled, but there is a need for much better understanding of the physical and chemical mechanisms that produce and consume them. We are using numerical modeling study the chemical reactions and fluid mechanical factors that occur in industrial processes: we are examining systems including premixed and diffusion flames, stirred reactors and plug flow reactors in these modeling studies to establish the major factors leading to emissions of these chemicals. In addition, we are applying advanced laser diagnostic techniques to validate the model predictions and to study the possibilities of developing sophisticated sensors to detect emissions of undesirable species in real time. This paper will discuss the organization of this collaborative effort and its results to date.

  1. A localised subgrid scale model for fluid dynamical simulations in astrophysics I: Theory and numerical tests

    E-Print Network [OSTI]

    Schmidt, W; Niemeyer, J C

    2006-01-01T23:59:59.000Z

    We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the sub...

  2. An improved neutral diffusion model and numerical solution of the two dimensional edge plasma fluid equations. Final report

    SciTech Connect (OSTI)

    Prinja, A.K.

    1998-09-01T23:59:59.000Z

    In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton`s method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria {epsilon} is set to be 10{sup {minus}9} based on the fact that lower value of {epsilon} does not alter the solution significantly. Correspondingly, the number of Newton`s iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton`s method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are relatively smooth as a consequence of the less localized recycling, leading to an improved convergence rate of the numerical algorithm. Peak plasma density is lower and the temperature correspondingly higher than those predicted by the standard diffusion model. It is believed that the FFCD model is more accurate. With both the TP continuation and multigrid methods, the author has demonstrated the robustness of these two methods. A mutually beneficial hybridization between the TP method and multigrid methods is clearly an alternative for edge plasma simulation. While the fundamental transport model considered in this work has ignored important physics such as drifts and currents, he has nevertheless demonstrated the versatility and robustness of the numerical scheme to handle such new physics. The application of gaseous-radiative divertor model in this work is just a beginning and up to this point numerically, the future is exciting.

  3. Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri

    SciTech Connect (OSTI)

    Rovey, Charles; Gouzie, Douglas; Biagioni, Richard

    2013-09-30T23:59:59.000Z

    The project titled Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri provided training for three graduate students in areas related to carbon capture and storage. Numerical modeling of CO{sub 2} injection into the St. Francois aquifer at the Southwest Power Plant Site in Greene County, Missouri indicates that up to 4.1 x 10{sup 5} metric tons of CO{sub 2} per year could be injected for 30 years without exceeding a 3 MPa differential injection pressure. The injected CO{sub 2} would remain sequestered below the top of the overlying caprock (St. Francois confining unit) for more than 1000 years. Geochemical modeling indicates that portions of the injected CO{sub 2} will react rapidly with trace minerals in the aquifer to form various solid carbonate mineral phases. These minerals would store significant portions of injected CO{sub 2} over geologic time scales. Finally, a GIS data base on the pore-fluid chemistry of the overlying aquifer system in Missouri, the Ozark aquifer, was compiled from many sources. This data base could become useful in monitoring for leakage from future CO{sub 2} sequestration sites.

  4. A phase screen model for simulating numerically the propagation of a laser beam in rain

    SciTech Connect (OSTI)

    Lukin, I P; Rychkov, D S; Falits, A V [Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation); Lai, Kin S; Liu, Min R [DSO National Laboratories 20 (Singapore)

    2009-09-30T23:59:59.000Z

    The method based on the generalisation of the phase screen method for a continuous random medium is proposed for simulating numerically the propagation of laser radiation in a turbulent atmosphere with precipitation. In the phase screen model for a discrete component of a heterogeneous 'air-rain droplet' medium, the amplitude screen describing the scattering of an optical field by discrete particles of the medium is replaced by an equivalent phase screen with a spectrum of the correlation function of the effective dielectric constant fluctuations that is similar to the spectrum of a discrete scattering component - water droplets in air. The 'turbulent' phase screen is constructed on the basis of the Kolmogorov model, while the 'rain' screen model utiises the exponential distribution of the number of rain drops with respect to their radii as a function of the rain intensity. Theresults of the numerical simulation are compared with the known theoretical estimates for a large-scale discrete scattering medium. (propagation of laser radiation in matter)

  5. Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 episodic events in southern Lake

    E-Print Network [OSTI]

    Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics

  6. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 1, Equations and numerics

    SciTech Connect (OSTI)

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01T23:59:59.000Z

    The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User`s Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions.

  7. Numerical modeling of carrier gas flow in atomic layer deposition vacuum reactor: A comparative study of lattice Boltzmann models

    SciTech Connect (OSTI)

    Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)

    2014-01-15T23:59:59.000Z

    This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice BhatnagarGrossKrook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.

  8. Full-Scale Numerical Modeling of Turbulent Processes in the Earth's Ionosphere

    SciTech Connect (OSTI)

    Eliasson, B. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Stenflo, L. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Department of Physics, Linkoeping University, SE-581 83 Linkoeping (Sweden); Shukla, P. K. [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2008-10-15T23:59:59.000Z

    We present a full-scale simulation study of ionospheric turbulence by means of a generalized Zakharov model based on the separation of variables into high-frequency and slow time scales. The model includes realistic length scales of the ionospheric profile and of the electromagnetic and electrostatic fields, and uses ionospheric plasma parameters relevant for high-latitude radio facilities such as Eiscat and HAARP. A nested grid numerical method has been developed to resolve the different length-scales, while avoiding severe restrictions on the time step. The simulation demonstrates the parametric decay of the ordinary mode into Langmuir and ion-acoustic waves, followed by a Langmuir wave collapse and short-scale caviton formation, as observed in ionospheric heating experiments.

  9. Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling

    SciTech Connect (OSTI)

    Rainey, E. S. G.; Kavner, A. [Department of Earth and Space Sciences, University of California, Los Angeles, California 90095 (United States); Hernlund, J. W. [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Earth-Life Science Institute, Megoro, Tokyo 152-8551 (Japan)

    2013-11-28T23:59:59.000Z

    We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a flat top input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.

  10. 19th. AIAA-CEAS Aeroacoutics Conference, May 28th 2013, Berlin Dynamic Modeling and Numerical Simulation of

    E-Print Network [OSTI]

    Huang, Xun

    19th. AIAA-CEAS Aeroacoutics Conference, May 28th 2013, Berlin Dynamic Modeling and Numerical was presented in this paper. By this control-oriented model, transient dynamic process of multi-physics coupling problem in a progressive wave tube could be approximately studied. The proposed model is verified

  11. An economic model of the limits to foraging range in central place foragers with numerical solutions for

    E-Print Network [OSTI]

    place. 2. The basic model can be varied to suit foragers that optimise either their rate of net energy uptake or their foraging efciency. 3. The model requires specication of the time and energy budgetsAn economic model of the limits to foraging range in central place foragers with numerical

  12. High Performance Computing Modeling Advances Accelerator Science for High Energy Physics

    SciTech Connect (OSTI)

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-04-29T23:59:59.000Z

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing (HPC) are essential for accurately modeling them. In the past decade, the DOE SciDAC program has produced such accelerator-modeling tools, which have beem employed to tackle some of the most difficult accelerator science problems. In this article we discuss the Synergia beam-dynamics framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable of handling the entire spectrum of beam dynamics simulations. We present the design principles, key physical and numerical models in Synergia and its performance on HPC platforms. Finally, we present the results of Synergia applications for the Fermilab proton source upgrade, known as the Proton Improvement Plan (PIP).

  13. High-Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Amundson, James [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Macridin, Alexandru [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Spentzouris, Panagiotis [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2014-11-01T23:59:59.000Z

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing (HPC) are essential for accurately modeling them. In the past decade, the DOE SciDAC program has produced such accelerator-modeling tools, which have beem employed to tackle some of the most difficult accelerator science problems. In this article we discuss the Synergia beam-dynamics framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable of handling the entire spectrum of beam dynamics simulations. We present the design principles, key physical and numerical models in Synergia and its performance on HPC platforms. Finally, we present the results of Synergia applications for the Fermilab proton source upgrade, known as the Proton Improvement Plan (PIP).

  14. High-Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-11-01T23:59:59.000Z

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing (HPC) are essential for accurately modeling them. In the past decade, the DOE SciDAC program has produced such accelerator-modeling tools, which have beem employed to tackle some of the most difficult accelerator science problems. In this article we discuss the Synergia beam-dynamics framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation packagemorecapable of handling the entire spectrum of beam dynamics simulations. We present the design principles, key physical and numerical models in Synergia and its performance on HPC platforms. Finally, we present the results of Synergia applications for the Fermilab proton source upgrade, known as the Proton Improvement Plan (PIP).less

  15. PI CONTROLLERS PERFORMANCES FOR A PROCESS MODEL WITH VARYING DELAY

    E-Print Network [OSTI]

    the obtained performances on a simplified hy- drodesulfurization process model we use as test case. 2 PI by a relay feedback as shown in [1]. Ziegler and Nichols then studied on a simple real process

  16. A Linear Parabolic Trough Solar Collector Performance Model

    E-Print Network [OSTI]

    Qu, M.; Archer, D.; Masson, S.

    2006-01-01T23:59:59.000Z

    A performance model has been programmed for solar thermal collector based on a linear, tracking parabolic trough reflector focused on a surface-treated metallic pipe receiver enclosed in an evacuated transparent tube: a Parabolic Trough Solar...

  17. Hybrid Model for Building Performance Diagnosis and Optimal Control

    E-Print Network [OSTI]

    Wang, S.; Xu, X.

    2003-01-01T23:59:59.000Z

    Modern buildings require continuous performance monitoring, automatic diagnostics and optimal supervisory control. For these applications, simplified dynamic building models are needed to predict the cooling and heating requirement viewing...

  18. Numerical simulations of the internal shock model in magnetized relativistic jets of blazars

    E-Print Network [OSTI]

    Rueda-Becerril, Jesus M; Aloy, Miguel A

    2015-01-01T23:59:59.000Z

    The internal shocks scenario in relativistic jets is used to explain the variability of the blazar emission. Recent studies have shown that the magnetic field significantly alters the shell collision dynamics, producing a variety of spectral energy distributions and light-curves patterns. However, the role played by magnetization in such emission processes is still not entirely understood. In this work we numerically solve the magnetohydodynamic evolution of the magnetized shells collision, and determine the influence of the magnetization on the observed radiation. Our procedure consists in systematically varying the shell Lorentz factor, relative velocity, and viewing angle. The calculations needed to produce the whole broadband spectral energy distributions and light-curves are computationally expensive, and are achieved using a high-performance parallel code.

  19. Experimental Validation of a Numerical Multizone Airflow and Pollutant Transfer Model

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    and long-term assessment of the performances of ventilation systems, the experimental house MARIA and ventilation systems are modeled in MATLAB/Simulink environment. This paper quickly describes the multi exhaust, balanced and natural ventilation systems. In addition, the virtual laboratory SIMBAD Building

  20. Numerical Modeling of Nonlinear Coupling between Lines/Beams with Multiple Floating Bodies

    E-Print Network [OSTI]

    Yang, Chan K.

    2010-07-14T23:59:59.000Z

    to be capable of modeling the tendon disconnection both at the top and the bottom connection as well as the down stroke behavior for the pinned bottom joint. The performance of the tie-down clamp of derrick is also investigated by using six degrees of freedom...

  1. Models used to assess the performance of photovoltaic systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Klise, Geoffrey T.

    2009-12-01T23:59:59.000Z

    This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

  2. Human performance modeling for system of systems analytics: combat performance-shaping factors.

    SciTech Connect (OSTI)

    Lawton, Craig R.; Miller, Dwight Peter

    2006-01-01T23:59:59.000Z

    The US military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives. To support this goal, Sandia National Laboratories (SNL) has undertaken a program of HPM as an integral augmentation to its system-of-system (SoS) analytics capabilities. The previous effort, reported in SAND2005-6569, evaluated the effects of soldier cognitive fatigue on SoS performance. The current effort began with a very broad survey of any performance-shaping factors (PSFs) that also might affect soldiers performance in combat situations. The work included consideration of three different approaches to cognition modeling and how appropriate they would be for application to SoS analytics. This bulk of this report categorizes 47 PSFs into three groups (internal, external, and task-related) and provides brief descriptions of how each affects combat performance, according to the literature. The PSFs were then assembled into a matrix with 22 representative military tasks and assigned one of four levels of estimated negative impact on task performance, based on the literature. Blank versions of the matrix were then sent to two ex-military subject-matter experts to be filled out based on their personal experiences. Data analysis was performed to identify the consensus most influential PSFs. Results indicate that combat-related injury, cognitive fatigue, inadequate training, physical fatigue, thirst, stress, poor perceptual processing, and presence of chemical agents are among the PSFs with the most negative impact on combat performance.

  3. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Large Kaplan Hydro Turbines

    SciTech Connect (OSTI)

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.

    2005-11-30T23:59:59.000Z

    BioIndex testing of hydro-turbines is sought as an analog to the hydraulic index testing conducted on hydro-turbines to optimize their power production efficiency. In BioIndex testing the goal is to identify those operations within the range identified by Index testing where the survival of fish passing through the turbine is maximized. BioIndex testing includes the immediate tailrace region as well as the turbine environment between a turbine's intake trashracks and the exit of its draft tube. The US Army Corps of Engineers and the Department of Energy have been evaluating a variety of means, such as numerical and physical turbine models, to investigate the quality of flow through a hydro-turbine and other aspects of the turbine environment that determine its safety for fish. The goal is to use these tools to develop hypotheses identifying turbine operations and predictions of their biological performance that can be tested at prototype scales. Acceptance of hypotheses would be the means for validation of new operating rules for the turbine tested that would be in place when fish were passing through the turbines. The overall goal of this project is to evaluate the performance of numerical blade strike models as a tool to aid development of testable hypotheses for bioIndexing. Evaluation of the performance of numerical blade strike models is accomplished by comparing predictions of fish mortality resulting from strike by turbine runner blades with observations made using live test fish at mainstem Columbia River Dams and with other predictions of blade strike made using observations of beads passing through a 1:25 scale physical turbine model.

  4. Java Programming for High Performance Numerical Computing J. E. Moreira S. P. Midkiff M. Gupta P. V. Artigas M. Snir R. D. Lawrence

    E-Print Network [OSTI]

    Goldstein, Seth Copen

    related to Java's applicability to solving large computational problems in science and engineering. Unless are an essential tool in many areas of science and engineering. Computations with complex numbers needJava Programming for High Performance Numerical Computing J. E. Moreira S. P. Midkiff M. Gupta P. V

  5. Numerical simulation of swirling flow in complex hydroturbine draft tube using unsteady statistical turbulence models

    SciTech Connect (OSTI)

    Paik, Joongcheol [University of Minnesota; Sotiropoulos, Fotis [University of Minnesota; Sale, Michael J [ORNL

    2005-06-01T23:59:59.000Z

    A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90 degree elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.

  6. Numerical Modeling of Thermal EOR: Comprehensive Coupling of an AMR-Based Model

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Flow and Geomechanics N. Guy*, G. Enchry and G. Renard IFP Energies nouvelles, 1-4 avenue de Bois of Thermal EOR: Comprehensive Coupling of an AMR-Based Model of Thermal Fluid Flow and Geomechanics when both thermal fluid flow and geomechanics are coupled in order to take into account variations

  7. Optimizing Mobile Application Performance with ModelDriven Engineering

    E-Print Network [OSTI]

    Schmidt, Douglas C.

    describes current research in developing an MDE tool for modeling mobile software architectures and using the following contributions to the study of mobile software development: (1) it shows how models of a mobile it difficult to test power consumption and performance until late in the software lifecycle [14], e.g., during

  8. Practical Performance Model for Bar Buckling Michael P. Berry1

    E-Print Network [OSTI]

    Eberhard, Marc O.

    Practical Performance Model for Bar Buckling Michael P. Berry1 and Marc O. Eberhard2 Abstract: A practical model has been developed to predict, for a given level of lateral deformation, the likelihood that longitudinal bars in a reinforced concrete column will have begun to buckle. Three relationships linking

  9. Computers and Chemical Engineering 26 (2002) 547554 A web-based library for testing performance of numerical software

    E-Print Network [OSTI]

    Brauner, Neima

    of the solution is in doubt. Unfortunately, the solution pro- vided by numerical solvers cannot always be trusted and Chemical Engineering 26 (2002) 547­554548 Table 1 Hiebert's (1983) version of the `combustion of propane

  10. Tidally averaged circulation in Puget Sound sub-basins: Comparison of historical data, analytical model, and numerical model

    SciTech Connect (OSTI)

    Khangaonkar, Tarang; Yang, Zhaoqing; Kim, Tae Yun; Roberts, Mindy

    2011-07-20T23:59:59.000Z

    Through extensive field data collection and analysis efforts conducted since the 1950s, researchers have established an understanding of the characteristic features of circulation in Puget Sound. The pattern ranges from the classic fjordal behavior in some basins, with shallow brackish outflow and compensating inflow immediately below, to the typical two-layer flow observed in many partially mixed estuaries with saline inflow at depth. An attempt at reproducing this behavior by fitting an analytical formulation to past data is presented, followed by the application of a three-dimensional circulation and transport numerical model. The analytical treatment helped identify key physical processes and parameters, but quickly reconfirmed that response is complex and would require site-specific parameterization to include effects of sills and interconnected basins. The numerical model of Puget Sound, developed using unstructured-grid finite volume method, allowed resolution of the sub-basin geometric features, including presence of major islands, and site-specific strong advective vertical mixing created by bathymetry and multiple sills. The model was calibrated using available recent short-term oceanographic time series data sets from different parts of the Puget Sound basin. The results are compared against (1) recent velocity and salinity data collected in Puget Sound from 2006 and (2) a composite data set from previously analyzed historical records, mostly from the 1970s. The results highlight the ability of the model to reproduce velocity and salinity profile characteristics, their variations among Puget Sound subbasins, and tidally averaged circulation. Sensitivity of residual circulation to variations in freshwater inflow and resulting salinity gradient in fjordal sub-basins of Puget Sound is examined.

  11. Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model

    E-Print Network [OSTI]

    Boyer, Edmond

    Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model in the coplanar orbit transfer problem M. Cerf1, T. Haberkorn, SADCO 2011, March 2nd M. Cerf, T. Haberkorn, E. Trelat Continuation from a flat to a round Earth model

  12. Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation and residual stresses

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    1 Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation.Bellet@mines-paristech.fr ABSTRACT The joining of high thickness steel sheets by means of hybrid Laser/GMAW welding processes of the workpiece borders. Two finite elements models are presented to illustrate: (i) A hybrid arc/laser welding

  13. An efficient numerical model for incompressible two-phase flow in fractured media Hussein Hoteit a,1

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    in fractured hydrocarbon reservoirs [16]. In this model, the matrixfracture mass transfer is describedAn efficient numerical model for incompressible two-phase flow in fractured media Hussein Hoteit a,1 , Abbas Firoozabadi a,b,* a Reservoir Engineering Research Institute, Palo Alto, CA, USA b Yale

  14. Numerical Modeling of Salt Tectonics on Passive Continental Margins: Preliminary Assessment of the Effects of Sediment Loading,

    E-Print Network [OSTI]

    Beaumont, Christopher

    Numerical Modeling of Salt Tectonics on Passive Continental Margins: Preliminary Assessment Sciences The University of Leeds LS2 9JT Leeds United Kingdom Abstract Salt tectonics in passive model of frictional-plastic sedimentary overburden overlying a linear viscous salt layer. We present

  15. Better Buildings Neighborhood Program Business Models Guide: Home Performance Contractor Business Model

    Broader source: Energy.gov [DOE]

    The home performance contractor model walks through the one-stop-shop model for home energy upgrades. It illustrates both the opportunities and barriers for starting as a home performance contractor company from the beginning, rather than expanding from an existing model, such as a remodeler.

  16. Human performance modeling for system of systems analytics :soldier fatigue.

    SciTech Connect (OSTI)

    Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

    2005-10-01T23:59:59.000Z

    The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

  17. Numerical modeling of tsunami waves generated by the flank collapse of the Cumbre Vieja Volcano (La Palma, Canary Islands)

    E-Print Network [OSTI]

    Kirby, James T.

    Palma, Canary Islands): Tsunami source and near field effects S. M. Abadie,1 J. C. Harris,2 S. T. Grilli of the Cumbre Vieja Volcano (CVV; La Palma, Canary Island, Spain) through numerical simulations performed in two of such wave trains on La Palma and other Canary Islands are assessed in detail in the paper. Citation: Abadie

  18. Numerical modeling of the elution peak profiles of retained solutes in supercritical fluid chromatography

    SciTech Connect (OSTI)

    Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL

    2011-01-01T23:59:59.000Z

    In supercritical fluid chromatography (SFC), the significant expansion of the mobile phase along the column causes the formation of axial and radial gradients of temperature. Due to these gradients, the mobile phase density, its viscosity, its velocity, its diffusion coefficients, etc. are not constant throughout the column. This results in a nonuniform flow velocity distribution, itself causing a loss of column efficiency in certain cases, even at low flow rates, as they do in HPLC. At high flow rates, an important deformation of the elution profiles of the sample components may occur. The model previously used to account satisfactorily for the retention of an unsorbed solute in SFC is applied to the modeling of the elution peak profiles of retained compounds. The numerical solution of the combined heat and mass balance equations provides the temperature and the pressure profiles inside the column and values of the retention time and the band profiles of retained compounds that are in excellent agreement with independent experimental data for large value of mobile phase reduced density. At low reduced densities, the band profiles can strongly depend on the column axial distribution of porosity.

  19. A numerical model of aerosol scavenging. Part 2, Simulation of a large city fire

    SciTech Connect (OSTI)

    Bradley, M.M.; Molenkamp, C.R.

    1991-10-01T23:59:59.000Z

    Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate.

  20. Numerical Modeling of Geomechanical Processes Related to CO{sub 2} Injection within Generic Reservoirs

    SciTech Connect (OSTI)

    Eckert, Andreas

    2013-05-31T23:59:59.000Z

    In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ?P{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ?P{sub c} magnitudes, especially for the compressional stress regime.

  1. Cost and Performance Model for Redox Flow Batteries

    SciTech Connect (OSTI)

    Viswanathan, Vilayanur V.; Crawford, Aladsair J.; Stephenson, David E.; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg W.; Thomsen, Edwin C.; Graff, Gordon L.; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.

    2014-02-01T23:59:59.000Z

    A cost model was developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling was done to estimate stack performance at various power densities as a function of state of charge. This was supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio, electrolyte flow channel dimensions were adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates were obtained from various vendors to calculate cost estimates for present, realistic and optimistic scenarios. The main drivers for cost reduction for various chemistries were identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guided suitability of various chemistries for different applications.

  2. Summary Results for Brine Migration Modeling Performed by LANL LBNL and SNL for the UFD Program

    SciTech Connect (OSTI)

    Kuhlman, Kristopher L

    2014-09-01T23:59:59.000Z

    This report summarizes laboratory and field observations and numerical modeling related to coupled processes involving brine and vapor migration in geologic salt, focusing on recent developments and studies conducted at Sandia, Los Alamos, and Berkeley National Laboratories. Interest into the disposal of heat-generating waste in salt has led to interest into water distribution and migration in both run-of-mine crushed and intact geologic salt. Ideally a fully coupled thermal-hydraulic-mechanical-chemical simulation is performed using numerical models with validated constitutive models and parameters. When mechanical coupling is not available, mechanical effects are prescribed in hydraulic models as source, boundary, or initial conditions. This report presents material associated with developing appropriate initial conditions for a non-mechanical hydrologic simulation of brine migration in salt. Due to the strong coupling between the mechanical and hydrologic problems, the initial saturation will be low for the excavation disturbed zone surrounding the excavation. Although most of the material in this report is not new, the author hopes it is presented in a format making it useful to other salt researchers.

  3. Stochastic Modeling and Performance Analysis of Multimedia SoCs

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Stochastic Modeling and Performance Analysis of Multimedia SoCs Balaji Raman1, Ayoub Nouri1, Deepak.raman@imag.fr Abstract--Quality of video and audio output is a design-time constraint for portable multimedia devices-case due to high variability in a multimedia system. In future mobile devices, the playout buffer size

  4. A Model of Extranet Implementation Success Effects on Business Performance

    E-Print Network [OSTI]

    A Model of Extranet Implementation Success Effects on Business Performance Sanna M. Kallioranta Ph and Justification The eBusiness revolution is impossible to ignore. It has transformed businesses in virtually every and services, and eBusiness has transformed the way companies interact with customers, partners and employees

  5. Performance and Energy Modeling for Live Migration of Virtual Machines

    E-Print Network [OSTI]

    Xu, Cheng-Zhong

    Performance and Energy Modeling for Live Migration of Virtual Machines Haikun Liu , Cheng-Zhong Xu , Hai Jin , Jiayu Gong , Xiaofei Liao School of Computer Science and Technology Huazhong University of Science and Technology Wuhan, 430074, China {hjin, xfliao}@hust.edu.cn Department of Electrical

  6. Developing Performance Models from Non-intrusive Monitoring Traces

    E-Print Network [OSTI]

    Murphy, John

    Developing Performance Models from Non- intrusive Monitoring Traces Daniela Mania, John Murphy transactions within the system at run-time using non-intrusive monitoring. Our belief is this methodology obtained by non-intrusive monitoring of an EJB-based e-commerce application. Moreover, the methodology

  7. MODELING THE PERFORMANCE OF HIGH BURNUP THORIA AND URANIA PWR FUEL

    E-Print Network [OSTI]

    Long, Y.

    Fuel performance models have been developed to assess the performance of ThO[subscript 2]-UO[subscript 2]

  8. Reference Manual for the System Advisor Model's Wind Power Performance Model

    SciTech Connect (OSTI)

    Freeman, J.; Jorgenson, J.; Gilman, P.; Ferguson, T.

    2014-08-01T23:59:59.000Z

    This manual describes the National Renewable Energy Laboratory's System Advisor Model (SAM) wind power performance model. The model calculates the hourly electrical output of a single wind turbine or of a wind farm. The wind power performance model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs. In SAM, the performance model can be coupled to one of the financial models to calculate economic metrics for residential, commercial, or utility-scale wind projects. This manual describes the algorithms used by the wind power performance model, which is available in the SAM user interface and as part of the SAM Simulation Core (SSC) library, and is intended to supplement the user documentation that comes with the software.

  9. Modelling Viscoelastic Behaviour of Polymer by A Mixed Velocity, Displacement Formulation - Numerical and Experimental Results

    SciTech Connect (OSTI)

    Pham, VT.; Silva, L.; Digonnet, H.; Combeaud, C.; Billon, N.; Coupez, T. [Centre for Material Forming (CEMEF), MINES ParisTech, Rue Claude Daunesse, Sophia Antipolis cedex (France)

    2011-05-04T23:59:59.000Z

    The objective of this work is to model the viscoelastic behaviour of polymer from the solid state to the liquid state. With this objective, we perform experimental tensile tests and compare with simulation results. The chosen polymer is a PMMA whose behaviour depends on its temperature. The computation simulation is based on Navier-Stokes equations where we propose a mixed finite element method with an interpolation P1+/P1 using displacement (or velocity) and pressure as principal variables. The implemented technique uses a mesh composed of triangles (2D) or tetrahedra (3D). The goal of this approach is to model the viscoelastic behaviour of polymers through a fluid-structure coupling technique with a multiphase approach.

  10. Numerical Realization of a Shell Model for Impurity Spreading in Plasmas

    SciTech Connect (OSTI)

    Tokar, M. Z.; Koltunov, M. [Institute for Energy and Climate Research-Plasma Physics, Research Center Juelich GmbH, Juelich, 52428 (Germany)

    2011-09-14T23:59:59.000Z

    In plasmas of fusion devices impurity particles are released as a consequence of wall erosion and are seeded deliberately for diverse purposes. Often they enter the plasma volume from small spots and spread away both along and perpendicular to the magnetic field. This process is described by continuity, motion and heat balance equations taking into account such physical processes as ionization by electrons, friction and heating in coulomb collisions with background ions, etc. In present paper we introduce a shell model where solutions of these equations, such as the densities of different impurity ions, are approximated by functions decaying exponentially from the source region due to the ionization into higher charged states. By integrating the original transport equations over several space regions, we get a set of ordinary differential equations describing the time evolution of the characteristic values for the impurity ion densities, fluxes, temperatures, and the dimensions along and across the magnetic field of the clouds where different states are predominantly localized. The equations obtained include time derivatives of complex non-linear combinations of the variables in question. Two numerical approaches to solve such equations are elaborated and compared by considering the spreading of lithium particles in deuterium plasma.

  11. On the spherically symmetrical combustion of methyl decanoate droplets and comparisons with detailed numerical modeling

    E-Print Network [OSTI]

    Walter, M.Todd

    .53­0.57 mm and the combustion gas is normal atmospheric pressure air. A detailed numerical simulationOn the spherically symmetrical combustion of methyl decanoate droplets and comparisons Biodiesel Biofuel Microgravity Numerical Droplet combustion a b s t r a c t This study presents

  12. The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and

    E-Print Network [OSTI]

    of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we and the perspectives for future research presented. Key words: tsunami waves, shallow water equations, tsunami

  13. PHARAO Laser Source Flight Model: Design and Performances

    E-Print Network [OSTI]

    Lvque, Thomas; Esnault, Franois-Xavier; Delaroche, Christophe; Massonnet, Didier; Grosjean, Olivier; Buffe, Fabrice; Torresi, Patrizia; Bomer, Thierry; Pichon, Alexandre; Braud, Pascal; Lelay, Jean-Pierre; Thomin, Stphane; Laurent, Philippe

    2015-01-01T23:59:59.000Z

    In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.

  14. Correlation between human observer performance and model observer performance in differential phase contrast CT

    SciTech Connect (OSTI)

    Li, Ke; Garrett, John [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

    2013-11-15T23:59:59.000Z

    Purpose: With the recently expanding interest and developments in x-ray differential phase contrast CT (DPC-CT), the evaluation of its task-specific detection performance and comparison with the corresponding absorption CT under a given radiation dose constraint become increasingly important. Mathematical model observers are often used to quantify the performance of imaging systems, but their correlations with actual human observers need to be confirmed for each new imaging method. This work is an investigation of the effects of stochastic DPC-CT noise on the correlation of detection performance between model and human observers with signal-known-exactly (SKE) detection tasks.Methods: The detectabilities of different objects (five disks with different diameters and two breast lesion masses) embedded in an experimental DPC-CT noise background were assessed using both model and human observers. The detectability of the disk and lesion signals was then measured using five types of model observers including the prewhitening ideal observer, the nonprewhitening (NPW) observer, the nonprewhitening observer with eye filter and internal noise (NPWEi), the prewhitening observer with eye filter and internal noise (PWEi), and the channelized Hotelling observer (CHO). The same objects were also evaluated by four human observers using the two-alternative forced choice method. The results from the model observer experiment were quantitatively compared to the human observer results to assess the correlation between the two techniques.Results: The contrast-to-detail (CD) curve generated by the human observers for the disk-detection experiments shows that the required contrast to detect a disk is inversely proportional to the square root of the disk size. Based on the CD curves, the ideal and NPW observers tend to systematically overestimate the performance of the human observers. The NPWEi and PWEi observers did not predict human performance well either, as the slopes of their CD curves tended to be steeper. The CHO generated the best quantitative agreement with human observers with its CD curve overlapping with that of human observer. Statistical equivalence between CHO and humans can be claimed within 11% of the human observer results, including both the disk and lesion detection experiments.Conclusions: The model observer method can be used to accurately represent human observer performance with the stochastic DPC-CT noise for SKE tasks with sizes ranging from 8 to 128 pixels. The incorporation of the anatomical noise remains to be studied.

  15. A New Model to Simulate Energy Performance of VRF Systems

    SciTech Connect (OSTI)

    Hong, Tianzhen; Pang, Xiufeng; Schetrit, Oren; Wang, Liping; Kasahara, Shinichi; Yura, Yoshinori; Hinokuma, Ryohei

    2014-03-30T23:59:59.000Z

    This paper presents a new model to simulate energy performance of variable refrigerant flow (VRF) systems in heat pump operation mode (either cooling or heating is provided but not simultaneously). The main improvement of the new model is the introduction of the evaporating and condensing temperature in the indoor and outdoor unit capacity modifier functions. The independent variables in the capacity modifier functions of the existing VRF model in EnergyPlus are mainly room wet-bulb temperature and outdoor dry-bulb temperature in cooling mode and room dry-bulb temperature and outdoor wet-bulb temperature in heating mode. The new approach allows compliance with different specifications of each indoor unit so that the modeling accuracy is improved. The new VRF model was implemented in a custom version of EnergyPlus 7.2. This paper first describes the algorithm for the new VRF model, which is then used to simulate the energy performance of a VRF system in a Prototype House in California that complies with the requirements of Title 24 ? the California Building Energy Efficiency Standards. The VRF system performance is then compared with three other types of HVAC systems: the Title 24-2005 Baseline system, the traditional High Efficiency system, and the EnergyStar Heat Pump system in three typical California climates: Sunnyvale, Pasadena and Fresno. Calculated energy savings from the VRF systems are significant. The HVAC site energy savings range from 51 to 85percent, while the TDV (Time Dependent Valuation) energy savings range from 31 to 66percent compared to the Title 24 Baseline Systems across the three climates. The largest energy savings are in Fresno climate followed by Sunnyvale and Pasadena. The paper discusses various characteristics of the VRF systems contributing to the energy savings. It should be noted that these savings are calculated using the Title 24 prototype House D under standard operating conditions. Actual performance of the VRF systems for real houses under real operating conditions will vary.

  16. Numerical Modeling of Reactive Multiphase Flow for FCC and Hot Gas Desulfurization Circulating Fluidized Beds

    SciTech Connect (OSTI)

    None

    2005-07-01T23:59:59.000Z

    This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.

  17. Numerical analysis of a finite element method for the axisymmetric eddy current model of an induction furnace

    E-Print Network [OSTI]

    Rodríguez, Rodolfo

    Numerical analysis of a finite element method for the axisymmetric eddy current model, 27002, Lugo, Spain The aim of this paper is to analyze a finite element method to solve an eddy current of the method are reported. Keywords: low-frequency harmonic Maxwell equations, eddy current problems, finite

  18. ERS SAR characterization of coastal polynyas in the Arctic and comparison with SSM/I and numerical model investigations

    E-Print Network [OSTI]

    Winsor, Peter

    ), and a numerical polynya model (NPM) forced by National Center for Environmental Predictions (NCEP) wind fields increases to .83. The NPM computes offshore coastal polynya widths, heat exchange, and ice production is that SAR images processed through the SAR polynya algorithm in combination with the NPM is a powerful tool

  19. IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full Waveform Acoustic

    E-Print Network [OSTI]

    Harrison, Mark

    1988-01-01T23:59:59.000Z

    IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full are given and then a discrete-time, explicit finite element procedure is defined and analysed, with finite on the existence, uniqueness and finite element approximation of the solution of Biot's equations were given in [15

  20. Numerical modeling of effect of polyurea on response of steel plates to impulsive loads in direct pressure-pulse experiments

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Numerical modeling of effect of polyurea on response of steel plates to impulsive loads in direct is studied, focusing on the effects of the relative position of polyurea with respect to the loading plates subjected to uniform blast loads and compared their predictions with experimental results. Bahei

  1. Segmentation and Tracking of Mesoscale Eddies in Numeric Ocean Models Vishal Sood, Bin John, Ramprasad Balasubramanian and Amit Tandon*

    E-Print Network [OSTI]

    Tandon, Amit

    Segmentation and Tracking of Mesoscale Eddies in Numeric Ocean Models Vishal Sood, Bin John suggested that the mesoscale eddies and mesoscale features play a strong role in carrying heat poleward oceanographers an invaluable tool to assess mesoscale eddies and the Lagrangian characteristics of this mesoscale

  2. Numerical modelling of erosion processes in the Himalayas of Nepal: effects of spatial variations of rock strength and precipitation

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Numerical modelling of erosion processes in the Himalayas of Nepal: effects of spatial variations of the morphology of mountain belts. Here we investigate the modalities of defor- mation in Central Nepal on a c that the pattern of uplift in Nepal is mainly dependent on both erodability and fault geometry, rather than

  3. Numerical and physical modeling of hydraulic structures Hydraulic structures are used to control the flow of water in hydropower developments, urban

    E-Print Network [OSTI]

    Barthelat, Francois

    Numerical and physical modeling of hydraulic structures Hydraulic structures are used to control, their solution is found either by physical hydraulic modeling or, more recently, by numerical modeling significantly reduce turbine efficiency and cause premature mechanical failure when they occur at hydropower

  4. Instruction-level performance modeling and characterization of multimedia applications

    SciTech Connect (OSTI)

    Luo, Y. [Los Alamos National Lab., NM (United States). Scientific Computing Group; Cameron, K.W. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Computer Science

    1999-06-01T23:59:59.000Z

    One of the challenges for characterizing and modeling realistic multimedia applications is the lack of access to source codes. On-chip performance counters effectively resolve this problem by monitoring run-time behaviors at the instruction-level. This paper presents a novel technique of characterizing and modeling workloads at the instruction level for realistic multimedia applications using hardware performance counters. A variety of instruction counts are collected from some multimedia applications, such as RealPlayer, GSM Vocoder, MPEG encoder/decoder, and speech synthesizer. These instruction counts can be used to form a set of abstract characteristic parameters directly related to a processor`s architectural features. Based on microprocessor architectural constraints and these calculated abstract parameters, the architectural performance bottleneck for a specific application can be estimated. Meanwhile, the bottleneck estimation can provide suggestions about viable architectural/functional improvement for certain workloads. The biggest advantage of this new characterization technique is a better understanding of processor utilization efficiency and architectural bottleneck for each application. This technique also provides predictive insight of future architectural enhancements and their affect on current codes. In this paper the authors also attempt to model architectural effect on processor utilization without memory influence. They derive formulas for calculating CPI{sub 0}, CPI without memory effect, and they quantify utilization of architectural parameters. These equations are architecturally diagnostic and predictive in nature. Results provide promise in code characterization, and empirical/analytical modeling.

  5. Proceedings of the Workshop on Numerical Modeling of Thermohydrological Flow in Fractured Rock Masses, Feb. 19-20, 1980, Berkeley, CA

    E-Print Network [OSTI]

    Witherspoon, P.A.

    2010-01-01T23:59:59.000Z

    Mathematical modeling of thermal energy storage in aquifers:presented at the Thermal Energy storage in aquifers1979; Aquifer thermal energy storagea numerical simulation

  6. Numerical study of the mass spectrum in the 2D O(3) sigma model with a theta term

    E-Print Network [OSTI]

    B. Alles; A. Papa

    2007-11-12T23:59:59.000Z

    It has been conjectured that the mass spectrum of the O(3) non-linear sigma model with a theta term in 2 dimensions may possess an excited state, which decays when theta is lowered from pi below a critical value. Since the direct numerical investigation of the model is prevented by a sign problem, we try to infer some information on the mass spectrum at real theta by studying the model at imaginary theta via analytic continuation. A modified Swendsen-Wang cluster algorithm has been introduced to simulate the model with the theta term.

  7. A MOUNTAIN-SCALE 3-D NUMERICAL MODEL FOR CHARACTERIZING UNSATURATED FLOW AND TRANSPORT IN FRACTURED VOLCANIC ROCK AT YUCCA MOUNTAIN

    SciTech Connect (OSTI)

    Yu-Shu Wu

    2006-02-28T23:59:59.000Z

    A three-dimensional site-scale numerical model has been developed to simulate water and gas flow, heat transfer, and radionuclide transport in the unsaturated zone of Yucca Mountain, Nevada, the American underground repository site for high level radioactive waste. The modeling approach is based on a mathematical formulation of coupled multiphase fluid and heat flow and tracer transport through porous and fractured rock. This model is intended for use in predicting current and future conditions in the unsaturated zone, so as to aid in assessing the system performance of the repository. In particular, an integrated modeling methodology is discussed for integrating a wide variety of moisture, pneumatic, thermal, and isotopic geochemical data into comprehensive modeling analyses. The reliability and accuracy of the model predictions were the subject of a comprehensive model calibration study, in which the model was calibrated against measured data, including liquid saturation, water potential, and temperature. This study indicates that the model is able to reproduce the overall system behavior at Yucca Mountain with respect to moisture profiles, pneumatic pressure and chloride concentration variations in different geological units, and ambient geothermal conditions.

  8. An evaluation of pocket-model, numerical readout breath alcohol testing instruments

    E-Print Network [OSTI]

    Van Tassel, William Edward

    2004-11-15T23:59:59.000Z

    Eight small-scale breath alcohol measurement devices were tested for accuracy, precision and the ability to not yield false positive and false negative readings. These pocket-sized breath testers (PMBTs), which provided numerical readout of Br...

  9. Two-dimensional numerical models of open-top hydrothermal convection at high Rayleigh and Nusselt

    E-Print Network [OSTI]

    Wilcock, William

    for Nu up to 5060. Solutions are characterized by an unstable bottom thermal boundary layer where equation. To avoid classical numerical artifacts such as nonphysical oscillatory behavior and artificial

  10. Duct thermal performance models for large commercial buildings

    SciTech Connect (OSTI)

    Wray, Craig P.

    2003-10-01T23:59:59.000Z

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of duct system improvements in California large commercial buildings, over a range of building vintages and climates. This assessment will provide a solid foundation for future efforts that address the energy efficiency of large commercial duct systems in Title 24. This report describes our work to address Objective 1, which includes a review of past modeling efforts related to duct thermal performance, and recommends near- and long-term modeling approaches for analyzing duct thermal performance in large commercial buildings.

  11. Three-dimensional numerical modeling of the influence of faults on groundwater flow at Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Cohen, Andrew J.B.

    1999-06-01T23:59:59.000Z

    Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how the faulted hydrogeologic structure influences groundwater flow from a proposed high-level nuclear waste repository. Simulations are performed using a 3-D model that has a unique grid block discretization to accurately represent the faulted geologic units, which have variable thicknesses and orientations. Irregular grid blocks enable explicit representation of these features. Each hydrogeologic layer is discretized into a single layer of irregular and dipping grid blocks, and faults are discretized such that they are laterally continuous and displacement varies along strike. In addition, the presence of altered fault zones is explicitly modeled, as appropriate. The model has 23 layers and 11 faults, and approximately 57,000 grid blocks and 200,000 grid block connections. In the past, field measurement of upward vertical head gradients and high water table temperatures near faults were interpreted as indicators of upwelling from a deep carbonate aquifer. Simulations show, however, that these features can be readily explained by the geometry of hydrogeologic layers, the variability of layer permeabilities and thermal conductivities, and by the presence of permeable fault zones or faults with displacement only. In addition, a moderate water table gradient can result from fault displacement or a laterally continuous low permeability fault zone, but not from a high permeability fault zone, as others postulated earlier. Large-scale macrodispersion results from the vertical and lateral diversion of flow near the contact of high and low permeability layers at faults, and from upward flow within high permeability fault zones. Conversely, large-scale channeling can occur due to groundwater flow into areas with minimal fault displacement. Contaminants originating at the water table can flow in a direction significantly different than that of the water table gradient, and isolated zones of contaminants will occur at the water table downgradient. This behavior is not predicted by traditional models of contaminant transport. In addition, the influence of a particular type of fault cannot be generalized; depending on the location where contaminants enter the saturated zone, faults may either enhance of inhibit vertical dispersion.

  12. A new strategy for discrete element numerical models: 2. Sandbox applications

    E-Print Network [OSTI]

    Sandiford, Mike

    and visualized by the modeler. Reliable modeling of geomechanic processes enables the structural interpreter

  13. Fuel Cell Power Model for CHP and CHHP Economics and Performance Analysis (Presentation)

    SciTech Connect (OSTI)

    Steward, D.; Penev, M.

    2010-03-30T23:59:59.000Z

    This presentation describes the fuel cell power model for CHP and CHHP economics and performance analysis.

  14. Photovoltaic Array Condition Monitoring Based on Online Regression of Performance Model

    E-Print Network [OSTI]

    Teodorescu, Remus

    Photovoltaic Array Condition Monitoring Based on Online Regression of Performance Model Sergiu Abstract -- Photovoltaic (PV) system performance can be degraded by a series of factors affecting the PV monitoring, fault detection, performance model, photovoltaic systems, regression analysis. I. INTRODUCTION

  15. A Bayesian Approach to Online Performance Modeling for Database Appliances using Gaussian Models

    E-Print Network [OSTI]

    Waterloo, University of

    agreements (SLAs) and to maintain peak performance for database management systems (DBMS), database, and resource provisioning. Accurately predicting response times of DBMS queries is necessary for a DBA an efficient and highly ac- curate online DBMS performance model that is robust in the face of changing

  16. A Bayesian Approach to Online Performance Modeling for Database Appliances using Gaussian Models

    E-Print Network [OSTI]

    Aboulnaga, Ashraf

    - tain peak performance for database management systems (DBMS), database administrators (DBAs) need. Accurately predicting response times of DBMS queries is necessary for a DBA to effectively achieve and highly accurate online DBMS performance model that is robust in the face of changing workloads, data

  17. Three-dimensional numerical modeling of smoke injection from large fires in the early post-nuclear-exchange environment

    SciTech Connect (OSTI)

    Bradley, M.M.; Peterson, K.R.; Rodriguez, D.J.

    1988-11-17T23:59:59.000Z

    During the hours immediately following a nuclear exchange, large fires could inject enormous quantities of smoke into the atmosphere. This smoke, together with dust from surface bursts, would severely restrict visibilities and darken the skies over large areas for days. This, in turn, could impact surface and air operations and systems. These effects could be mitigated by various scavenging mechanisms within the convective clouds that form above the fires. In order to evaluate impacts of post-nuclear-exchange smoke injection, we are developing a three-dimensional numerical smoke plume model (OCTET) to simulate the dynamics and microphysical processes within smoke plumes and convective clouds above large fires. This model is based on the dynamic framework of the Klemp-Wilhelmson (1978) convective storm model and includes parameterizations of scavenging processes. In addition, we are combining results of laboratory research, field experiments, and detailed numerical modeling of cloud microphysical processes in order to better understand smoke scavenging mechanisms. In this brief demonstration of capabilities, we present results from the OCTET model and from a three-dimensional mesoscale model. The smoke plume and fire-induced cloud simulations demonstrate the effects of nucleation scavenging, seasonal variation of atmospheric stability, and various fuel sources. The mesoscale simulations (that use the plume model output as input) demonstrate the mesoscale transport and diffusion of smoke and predict optical depths over the hypothetical target area. No dust effects have been included in these simulations. 2 refs., 8 figs.

  18. Stochastic PV performance/reliability model : preview of alpha version.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Miller, Steven P.

    2010-03-01T23:59:59.000Z

    Problem Statement: (1) Uncertainties in PV system performance and reliability impact business decisions - Project cost and financing estimates, Pricing service contracts and guarantees, Developing deployment and O&M strategies; (2) Understanding and reducing these uncertainties will help make the PV industry more competitive (3) Performance has typically been estimated without much attention to reliability of components; and (4) Tools are needed to assess all inputs to the value proposition (e.g., LCOE, cash flow, reputation, etc.). Goals and objectives are: (1) Develop a stochastic simulation model (in GoldSim) that can represent PV system performance as a function of system design, weather, reliability, and O&M policies; (2) Evaluate performance for an example system to quantify sources of uncertainty and identify dominant parameters via a sensitivity study; and (3) Example System - 1 inverter, 225 kW DC Array latitude tilt (90 strings of 12 modules {l_brace}1080 modules{r_brace}), Weather from Tucumcari, NM (TMY2 with annual uncertainty).

  19. The Coupling of the Numerical Heat Transfer Model of the Pauzhetka Hydrothermal System (Kamchatka, USSR) with Hydroisotopic Data

    SciTech Connect (OSTI)

    Kiryukhin, A.V.; Sugrobov, V.M.

    1986-01-21T23:59:59.000Z

    The application of the two-dimensional numerical heat-transfer model to the Pauzhetka hydrothermal system allowed us to establish that: (1) a shallow magma body with the anomalous temperature of 700-1000 C and with a volume of 20-30 km{sup 3} may be a heat source for the formation of the Pauzhetka hydrothermal system. (2) The water feeding source of the Pauzhetka hydrothermal system may be meteoric waters which are infiltrated at an average rate of 5-10 kg/s {center_dot} km{sup 2}. The coupling of the numerical heat-transfer model with hydroisotopic data (D,T,{sup 18}O) obtained from the results of testing of exploitation wells, rivers and springs is the basis to understand more clearly the position of recharge areas and the structure of water flows in the hydrothermal system.

  20. Scalar-Scalar Ladder Model in the Unequal-Mass Case. III - Numerical Studies of the P-Wave Case -

    E-Print Network [OSTI]

    Ichio Fukui; Noriaki Setoh

    1999-01-21T23:59:59.000Z

    The eigenvalue problem for the p-wave bound states formed by two unequal-mass scalar particles through the massive scalar particle exchange is analyzed numerically in the framework of the Bethe-Salpeter ladder model. As in the s-wave case, the eigenvalues of the coupling constant are found to become complex for some mass configurations in some range of the bound state mass. The Bethe-Salpeter amplitudes of the low-lying bound states are also investigated.

  1. A numerical procedure to model and monitor CO2 sequestration in

    E-Print Network [OSTI]

    Santos, Juan

    area of research. o We present a methodology integrating numerical simulation of CO2 -brine o The simultaneous flow of brine and CO2 is described by the well-known Black in the brine but the brine is not allowed to vaporize into the CO2 phase. o This formulation uses

  2. Numerical modeling of observed effective flow behavior in unsaturated heterogeneous sands

    E-Print Network [OSTI]

    Wildenschild, Dorthe

    , and a stochastic theory were compared to effective retention and hydraulic conductivity characteristics measured slow a response in the outflow rate. An alternative approach involving a combination of arithmetic, deterministic simulations would demand vast computa- tional resources by requiring an extremely dense numerical

  3. Numerical and analytical modelling of entropy noise in a supersonic nozzle with a shock

    E-Print Network [OSTI]

    Boyer, Edmond

    and numerical assessments of the indirect noise generated through a nozzle are presented. The configuration. Rohle, F. Thiele, B. Noll, The Entropy Wave Generator (EWG): A reference case on entropy noise, Journal of Sound and Vibration 326 (2009) 574-598] where an entropy wave is generated upstream of a nozzle

  4. LABORATORY-NUMERICAL MODEL COMPARISONS OF CANYON FLOWS: A PARAMETER STUDY.

    E-Print Network [OSTI]

    , but the enhanced viscosities needed to obtain numerical stability give boundary layers that are too wide along length scales, one the fluid depth and another a more narrow boundary-layer-like thickness [O(RoBu-1 is the interaction of an oscillatory, along-slope background current with an isolated canyon incised in an otherwise

  5. Overland flow modelling with the Shallow Water Equation using a well balanced numerical scheme

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    or kinematic waves equations, and using either finite volume or finite difference method. We compare these four show that, for relatively simple configurations, kinematic waves equations solved with finite volume; finite differ- ences scheme; kinematic wave equations; shallow water equations; comparison of numerical

  6. Numerical modeling of extreme rogue waves generated by directional energy focusing

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    of an overturning rogue wave, and analyze the sensitivity of its geometry and kinematics to water depth and maximum. Keywords: Water waves; Numerical wave tank; Extreme wave kinematics; Rogue waves 1. Introduction finely resolved 3D focused overturning waves and analyze their geometry and kinematics. In this paper, we

  7. Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems

    E-Print Network [OSTI]

    LaRocca, Sarah; Hassel, Henrik; Guikema, Seth

    2013-01-01T23:59:59.000Z

    Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist which can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. Thus in this paper, we suggest a classification of these models, which span from simple topologically-oriented models to advanced physical flow-based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this pa...

  8. PERFORMANCE MODELING OF DAYLIGHT INTEGRATED PHOTOSENSOR- CONTROLLED LIGHTING SYSTEMS

    E-Print Network [OSTI]

    S. Jain; R. R. Creasey; J. Himmelspach; K. P. White; M. Fu; Richard G. Mistrick

    Some building energy codes now require the incorporation of daylight into buildings and automatic photosensor-controlled switching or dimming of the electric lighting system in areas that receive daylight. This paper describes enhancements to the open-source Daysim daylight analysis software that permit users to model a photosensor control system as it will perform in a real space, considering the directional sensitivity of the photosensor, its mounting position, the space and daylight aperture geometry, window shading configuration; the electric lighting equipment and control zones; exterior obstructions; and site weather conditions. System output includes assessment of the daylight distribution in a space throughout the year, the photosensors ability to properly track the daylight and modify electric lighting system output, and the energy savings provided by the modeled control system. The application of daylight coefficients permits annual simulations to be conducted efficiently using hourly or finer weather data time increments. 1

  9. Course Description The summer school will cover theoretical and numerical methods for modeling microstructure

    E-Print Network [OSTI]

    Fabry, Frederic

    and hands-on work using high performance computing. Syllabus: Ginzburg-Landau theory and phase field of Physics & Faculty of Science, McGill University, CLUMEQ High Performance Computing Centre, Calcul Qubec

  10. Numerical study on transient heat transfer under soil with plastic mulch in agriculture applications using a nonlinear finite element model

    E-Print Network [OSTI]

    De Castro, Carlos Armando

    2011-01-01T23:59:59.000Z

    In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.

  11. Field observations and numerical model experiments for the snowmelt process at a field site

    E-Print Network [OSTI]

    Ohara, N; Kawas, M L

    2006-01-01T23:59:59.000Z

    a one dimensional heat transfer model is introduced in orderone dimensional heat transfer model is con- venient forHowever, the simple heat transfer model is a useful tool to

  12. Numerical investigation of the heating process inside an industrial furnace

    E-Print Network [OSTI]

    Wolper, Pierre

    Numerical investigation of the heating process inside an industrial furnace Proposition: Combined furnace taking into account convective, conductive and radiative heat transfer. The model: Catalysis, Energy Materials, Performance Materials and Recycling. Each business area is divided into market

  13. Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area

    SciTech Connect (OSTI)

    Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.

    2012-03-19T23:59:59.000Z

    To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.

  14. Modelling of Remediation Technologies at the Performance Assessment Level

    SciTech Connect (OSTI)

    Parton, N.J.; Paksy, A.; Eden, L.; Trivedi, D.P. [Nexia Solutions Limited, Hinton House, Risley, Warrington, Cheshire, UK, WA (United States)

    2008-07-01T23:59:59.000Z

    This paper presents approaches to modelling three different remediation technologies that are designed to support site operators during their assessment of remediation options for the management of radioactively contaminated land on nuclear licensed sites in the UK. The three selected technologies were soil washing, permeable reactive barrier and in-situ stabilisation. The potential exists to represent electrokinetics in the future. These technologies were chosen because it was considered that enough information already existed for site operators to assess mature technologies such as soil dig and disposal and groundwater pump and treat. Using the software code GoldSim, the models have been designed to allow site operators to make both a reasonable scoping level assessment of the viability of treatment and understand the cost-benefits of each technology. For soil washing, a standard soil leaching technique was simulated whereby the soil is separated into fines and oversize particles, and subsequently a chemical reagent is used to strip contamination off the soil. The cost benefit of this technology in terms of capital costs for the plant and materials, operational costs and waste disposal costs can also be assessed. The permeable reactive barrier (PRB) model can represent either a continuous wall or a funnel and gate system. The model simulates the transport of contaminants through the reactive material contained in the PRB. The outputs from the model include concentration of contaminants in the groundwater flow downstream of the PRB, mass of contaminants retained by the PRB, total mass and volume of waste and the various costs associated with the PRB remediation technology. The in-situ stabilisation (ISS) model has the capability to represent remediation by the addition of reagents that immobilise contaminated soil. The model simulates the release of contaminants from the treated soil over time. Performance is evaluated by comparison of the mass of contaminants retained and released to the area outside the treatment zone. Other outputs include amount of spoil generated (to be treated as waste) and the costs associated with the application of the ISS technology. These models are aimed to help users select a technology or technologies that are potentially suitable for a particular site. It is anticipated that they will prompt the user to undertake more detailed assessments to tailor the selected technology to their site specific circumstances and contaminated land conditions. (author)

  15. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    determined. A deterministic model includes both a dynamic model, and a static model. Compared to a deterministic solute diffusion model, a stochastic diffusion model has one or more stochastic elements. Concentration diffusion system formulated... solute diffusion equation, which merely appears in the form of a number line, the quasi-2D solute diffusion equation forms a Cartesian grid system. Also, for the explicit quasi-2D solute diffusion equation (Eq. 4), concentration variation is measured...

  16. Modeling operator performance in low task load supervisory domains

    E-Print Network [OSTI]

    Mkrtchyan, Armen A

    2011-01-01T23:59:59.000Z

    Currently, numerous automated systems need constant monitoring but require little to no operator interaction for prolonged periods, such as unmanned aerial systems, nuclear power plants, and air traffic management systems. ...

  17. Performance Evaluation of K-DEMO Cable-in-conduit Conductors Using the Florida Electro-Mechanical Cable Model

    SciTech Connect (OSTI)

    Zhai, Yuhu

    2013-07-16T23:59:59.000Z

    The United States ITER Project Office (USIPO) is responsible for design of the Toroidal Field (TF) insert coil, which will allow validation of the performance of significant lengths of the conductors to be used in the full scale TF coils in relevant conditions of field, current density and mechanical strain. The Japan Atomic Energy Agency (JAEA) will build the TF insert which will be tested at the Central Solenoid Model Coil (CSMC) Test facility at JAEA, Naka, Japan. Three dimensional mathematical model of TF Insert was created based on the initial design geometry data, and included the following features: orthotropic material properties of superconductor material and insulation; external magnetic field from CSMC, temperature dependent properties of the materials; pre-compression and plastic deformation in lap joint. Major geometrical characteristics of the design were preserved including cable jacket and insulation shape, mandrel outline, and support clamps and spacers. The model is capable of performing coupled structural, thermal, and electromagnetic analysis using ANSYS. Numerical simulations were performed for room temperature conditions; cool down to 4K, and the operating regime with 68kA current at 11.8 Tesla background field. Numerical simulations led to the final design of the coil producing the required strain levels on the cable, while simultaneously satisfying the ITER magnet structural design criteria.

  18. Direct-Steam Linear Fresnel Performance Model for NREL's System Advisor Model

    SciTech Connect (OSTI)

    Wagner, M. J.; Zhu, G.

    2012-09-01T23:59:59.000Z

    This paper presents the technical formulation and demonstrated model performance results of a new direct-steam-generation (DSG) model in NREL's System Advisor Model (SAM). The model predicts the annual electricity production of a wide range of system configurations within the DSG Linear Fresnel technology by modeling hourly performance of the plant in detail. The quasi-steady-state formulation allows users to investigate energy and mass flows, operating temperatures, and pressure drops for geometries and solar field configurations of interest. The model includes tools for heat loss calculation using either empirical polynomial heat loss curves as a function of steam temperature, ambient temperature, and wind velocity, or a detailed evacuated tube receiver heat loss model. Thermal losses are evaluated using a computationally efficient nodal approach, where the solar field and headers are discretized into multiple nodes where heat losses, thermal inertia, steam conditions (including pressure, temperature, enthalpy, etc.) are individually evaluated during each time step of the simulation. This paper discusses the mathematical formulation for the solar field model and describes how the solar field is integrated with the other subsystem models, including the power cycle and optional auxiliary fossil system. Model results are also presented to demonstrate plant behavior in the various operating modes.

  19. Observational and Numerical Modeling Studies of Turbulence on the Texas-Louisiana Continental Shelf

    E-Print Network [OSTI]

    Zhang, Zheng

    2013-05-24T23:59:59.000Z

    values to CH model values for (a) q= k, (b) P , (c) B, (d) t, (e) 0t, (f) M 2, and (g) N2. . . . . . . . . . . . . . . . . 58 2.19 Ratios of values between the models: (a) SG/CHx; (b) SGx/CH; (c) SG/SGx; (d) CHx... between depths of 6 and 15 m; (b) sum of the turbulent oxygen uxes at the layers. . . . . . . . . . . . . . . . . . . 80 xvii 3.11 (a) observed ; (b) CH modeled ; (c) SG modeled ; (d) observed ; (e) CH modeled ; (f) SG modeled . The SBL and BBL...

  20. Numerical Modeling of Diffusion in Fractured Media for Gas-Injection

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    ; Arana 2001; Darvish et al. 2006). Coats (1989) has modeled the effect of diffusion in dual- porosity

  1. A numerical model for the coupled long-term evolution of salt marshes and tidal flats

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    -shore mudflat model that takes into account tidal effects; Waeles et al. [2004] incor- porated in the same

  2. Computational Human Performance Modeling For Alarm System Design

    SciTech Connect (OSTI)

    Jacques Hugo

    2012-07-01T23:59:59.000Z

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  3. A Numerical Model for Miscible Displacement of Multi-Component Reactive Species

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . Azarouala a Water Department/Groundwater and Geochemistry Modeling, BRGM (French Geological Survey) 3 of our approach. Therefore, the model may prove useful for many practical applications. 1. INTRODUCTION Demands to undertake modeling analysis of coupled groundwater ow, solute transport, and reactive water

  4. Development of a Model Specification for Performance Monitoring Systems for Commercial Buildings

    E-Print Network [OSTI]

    Development of a Model Specification for Performance Monitoring Systems for Commercial Buildings the development of a model specification for performance monitoring systems for commercial buildings capabilities in #12;commercial buildings by demonstrating the capabilities of commercially available technology

  5. Joint flow-seismic inversion for characterizing fractured reservoirs: theoretical approach and numerical modeling

    E-Print Network [OSTI]

    Kang, Peter K.

    2013-01-01T23:59:59.000Z

    Traditionally, seismic interpretation is performed without any account of the flow behavior. Here, we present a methodology to characterize fractured geologic media by integrating flow and seismic data. The key element of ...

  6. Proceedings of the workshop on numerical modeling of thermohydrological flow in fractured rock masses

    SciTech Connect (OSTI)

    Not Available

    1980-09-01T23:59:59.000Z

    Nineteen papers were presented at the workshop on modeling thermohydrologic flow in fractured masses. This workshop was a result of the interest currently being given to the isolation of nuclear wastes in geologic formations. Included in these proceedings are eighteen of the presentations, one abstract and summaries of the panel discussions. The papers are listed under the following categories: introduction; overviews; fracture modelings; repository studies; geothermal models; and recent developments. Eighteen of the papers have been abstracted and indexed.

  7. THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES

    E-Print Network [OSTI]

    Wang, J.S.Y.

    2013-01-01T23:59:59.000Z

    Doughty, 1979a, Aquifer thermal energy storage--a numericalical modeling of thermal energy storage in aquifers.Presented at the Thermal Energy Storage in Aquifers

  8. Aerosol dispersion and coagulation from a coal-fired power plant: a three dimensional numerical model

    SciTech Connect (OSTI)

    Buckholtz, H.T.; Biermann, A.H.

    1980-01-01T23:59:59.000Z

    A computational model to simulate the dispersion and coagulation of aerosols emitted from coal-fired power plants was constructed. In modeling the dispersion of the aerosol, turbulent diffusion and wind-driven advection are treated by a finite-difference method. Molecular coagulation is incorporated in the model to follow shifts in the particle-size distribution. Particulate coagulation is mathematically described by Timiskii's equation. The relevent semi-empirical work of Smirnov is incorporated in the model to provide for the coagultion constant. Input for the model is a bimodal, particle-size distribution measured at an operating coal-fired power plant. Simulations indicate that dispersion competes against coagulation mechanisms to maintain the bimodal shaped distribution for 32 km. Turbulence and particle settling tend to enchance coagulation effects. The size-dependent spatial segregation of particles within the plume is predicted.

  9. AGING PERFORMANCE OF MODEL 9975 PACKAGE FLUOROELASTOMER O-RINGS

    SciTech Connect (OSTI)

    Hoffman, E.; Daugherty, W.; Skidmore, E.; Dunn, K.; Fisher, D.

    2011-05-31T23:59:59.000Z

    The influence of temperature and radiation on Viton{reg_sign} GLT and GLT-S fluoroelastomer O-rings is an ongoing research focus at the Savannah River National Laboratory. The O-rings are credited for leaktight containment in the Model 9975 shipping package used for transportation of plutonium-bearing materials. At the Savannah River Site, the Model 9975 packages are being used for interim storage. Primary research efforts have focused on surveillance of O-rings from actual packages, leak testing of seals at bounding aging conditions and the effect of aging temperature on compression stress relaxation behavior, with the goal of service life prediction for long-term storage conditions. Recently, an additional effort to evaluate the effect of aging temperature on the oxidation of the materials has begun. Degradation in the mechanical properties of elastomers is directly related to the oxidation of the polymer. Sensitive measurements of the oxidation rate can be performed in a more timely manner than waiting for a measurable change in mechanical properties, especially at service temperatures. Measuring the oxidation rate therefore provides a means to validate the assumption that the degradation mechanisms(s) do not change from the elevated temperatures used for accelerated aging and the lower service temperatures. Monitoring the amount of oxygen uptake by the material over time at various temperatures can provide increased confidence in lifetime predictions. Preliminary oxygen consumption analysis of a Viton GLT-based fluoroelastomer compound (Parker V0835-75) using an Oxzilla II differential oxygen analyzer in the temperature range of 40-120 C was performed. Early data suggests oxygen consumption rates may level off within the first 100,000 hours (10-12 years) at 40 C and that sharp changes in the degradation mechanism (stress-relaxation) are not expected over the temperature range examined. This is consistent with the known long-term heat aging resistance of fluoroelastomers relative to hydrocarbon-based elastomers, and in absence of antioxidants that may be consumed over time. Additional experimental effort will be undertaken in the short term range within the first 100 hours of thermal aging to capture further details of the oxygen consumption rate.

  10. Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1

    SciTech Connect (OSTI)

    Gupta, Prabhat Kumar [Raja Ramanna Centre for Advanced Technology (RRCAT), Indore (MP), India; Rabehl, Roger [FNAL

    2014-07-01T23:59:59.000Z

    Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.

  11. MICROMECHANICS BASED CONSTITUTIVE MODEL FOR GRANULAR SOLIDS AND ITS IMPLEMENTATION INTO MESHFREE NUMERICAL METHOD

    E-Print Network [OSTI]

    Lusk, Miriam Beatriz

    2011-12-31T23:59:59.000Z

    To capture the fracture process and non-linear behavior at the element and structural level of granular materials, concrete, under the presence of pre-existing imperfections, a constitutive model and a mesh free method is ...

  12. Airborne observations and numerical modeling of fetch- limited waves in the Gulf of Tehuantepec

    E-Print Network [OSTI]

    Romero, Leonel

    2008-01-01T23:59:59.000Z

    velocity scaling in wind wave generation. Boundary-Layerlinear theory of of wind wave generation applied to waveSource terms in a third-generation wind wave model. J. Phys.

  13. Numerical Modeling of Fractured Shale-Gas and Tight-Gas Reservoirs Using Unstructured Grids

    E-Print Network [OSTI]

    Olorode, Olufemi Morounfopefoluwa

    2012-02-14T23:59:59.000Z

    Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non...

  14. NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES

    E-Print Network [OSTI]

    Patel, Harsh Jay

    2013-09-27T23:59:59.000Z

    , an innovative modeling approach was employed that focuses on the interface growth of the microbial mat surfaces using a combined stochastic and deterministic approach. A range of different initial conditions were simulated to evaluate the 3D topography evolution...

  15. THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES

    E-Print Network [OSTI]

    Wang, J.S.Y.

    2013-01-01T23:59:59.000Z

    studies related to the Cerro Prieto Field: Proceedings, 1stSymposium on the Cerro Prieto Geothermal Field, San Diego,modeling studies of the Cerro Prieto Reservoir--A progress

  16. Mathematical Modelling and Numerical Analysis Will be set by the publisher Modelisation Mathematique et Analyse Numerique

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    of underground storage facilities for nuclear waste. The processes involved in near-field models are extremely field u : [0, T ] R3 and a pressure field p : [0, T ] R such that - (u) + b p = f, in [0

  17. Efficient Conservative Numerical Schemes for 1D Nonlinear Spherical Diffusion Equations with Applications in Battery Modeling

    E-Print Network [OSTI]

    Zeng, Yi

    Mathematical models of batteries which make use of the intercalation of a species into a solid phase need to solve the corresponding mass transfer problem. Because solving this equation can significantly add to the ...

  18. University of Stuttgart IWS, Department of Hydromechanics and Modelling of Hydrosystems Numerical investigation of microbially

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    vicinity Abandoned wellCO2 2 #12;University of Stuttgart IWS, Department of Hydromechanics and Modelling discretization cap rock precipitated calcite reservoir radius of several meters injection of bacteria, urea

  19. Numerical modeling of fluid flow and time-lapse seismics to monitor ...

    E-Print Network [OSTI]

    santos

    May 30, 2014 ... including the presence of shale seals and fractures and fractal variations of the ... In the Black-Oil model employed, brine is NOT present, OIL is.

  20. Final Report: A Model Management System for Numerical Simulations of Subsurface Processes

    SciTech Connect (OSTI)

    Zachmann, David

    2013-10-07T23:59:59.000Z

    The DOE and several other Federal agencies have committed significant resources to support the development of a large number of mathematical models for studying subsurface science problems such as groundwater flow, fate of contaminants and carbon sequestration, to mention only a few. This project provides new tools to help decision makers and stakeholders in subsurface science related problems to select an appropriate set of simulation models for a given field application.

  1. Using Machine Learning to Create Turbine Performance Models (Presentation)

    SciTech Connect (OSTI)

    Clifton, A.

    2013-04-01T23:59:59.000Z

    Wind turbine power output is known to be a strong function of wind speed, but is also affected by turbulence and shear. In this work, new aerostructural simulations of a generic 1.5 MW turbine are used to explore atmospheric influences on power output. Most significant is the hub height wind speed, followed by hub height turbulence intensity and then wind speed shear across the rotor disk. These simulation data are used to train regression trees that predict the turbine response for any combination of wind speed, turbulence intensity, and wind shear that might be expected at a turbine site. For a randomly selected atmospheric condition, the accuracy of the regression tree power predictions is three times higher than that of the traditional power curve methodology. The regression tree method can also be applied to turbine test data and used to predict turbine performance at a new site. No new data is required in comparison to the data that are usually collected for a wind resource assessment. Implementing the method requires turbine manufacturers to create a turbine regression tree model from test site data. Such an approach could significantly reduce bias in power predictions that arise because of different turbulence and shear at the new site, compared to the test site.

  2. This Ph.D thesis encompasses a global numerical simulation of the needleeye float zone process, used to grow silicon single crystals. The numerical models includes coupled electro

    E-Print Network [OSTI]

    and free surface models and a global heat transfer model, with moving boundaries. An axisymmetric fluid to determine flow field, after the phase boundaries have been determined, by the heat transfer model. A finite field, from which temperature gradients are determined. The heat transfer model is furthermore expanded

  3. Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method

    E-Print Network [OSTI]

    Min, Kyoung

    2013-07-16T23:59:59.000Z

    are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering...

  4. Synthesis of Numerical Methods for Modeling Wave Energy Converter-Point Absorbers: Preprint

    SciTech Connect (OSTI)

    Li, Y.; Yu, Y. H.

    2012-05-01T23:59:59.000Z

    During the past few decades, wave energy has received significant attention among all ocean energy formats. Industry has proposed hundreds of prototypes such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber as the technology to extract wave energy. Several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. However, no standardized method has been decided. To assist the development of wave energy conversion technologies, this report reviews the methods for modeling the floating-point absorber.

  5. Numerical model for the vacuum pyrolysis of scrap tires in batch reactors

    SciTech Connect (OSTI)

    Yang, J.; Tanguy, P.A.; Roy, C. [Univ. Laval, Quebec, PQ (Canada). Dept. de Genie Chimique] [Univ. Laval, Quebec, PQ (Canada). Dept. de Genie Chimique

    1995-06-01T23:59:59.000Z

    A quantitative model for scrap tire pyrolysis in a batch scale reactor developed comprises the following basic phenomena: conduction inside tire particles; conduction, convection, and radiation between the feedstock particles or between the fluids and the particles; tire pyrolysis reaction; exothermicity and endothermicity caused by tire decomposition and volatilization; and the variation of the composition and the thermal properties of tire particles. This model was used to predict the transient temperature and density distributions in the bed of particles, the volatile product evolution rate, the mass change, the energy consumption during the pyrolysis process, and the pressure history in a tire pyrolysis reactor with a load of 1 kg. The model predictions agree well with independent experimental data.

  6. Numerical Modelling of a Pulse Combustion Burner: Limiting Conditions of Stable

    E-Print Network [OSTI]

    Vuik, Kees

    -called thermal pulse combustor. By integrating the model equations in time it is possible to predict whether A thermal pulse combustion. Figure 1 gives a schematic representation of such a thermal pulse combustor combustors may give important guide- lines on how design parameters should be chosen. This paper gives

  7. Model Validation and Spatial Interpolation by Combining Observations with Outputs from Numerical

    E-Print Network [OSTI]

    Washington at Seattle, University of

    ""r,c,rn The authors are for hel]JfuI #12;Abstract Constructing maps of pollution levels is vital for air quality concentrations. Key tlJords: air pollution, Ba~yesian inference, change of support, likelihood approaches, Matern Resolutions 2.5 Modeling a Nonstationary Covariance . 3 Estimation 3.1 Algorithm 4 Application: Air Pollution

  8. A numerical procedure to model and monitor CO2 sequestration in

    E-Print Network [OSTI]

    Santos, Juan

    sequestration over very long periods of time. The analysis of CO2 underground storage safety in the long term procedure to model and monitor CO2 sequestration in aquifers p. #12;Introduction. I Storage of CO2 (31.6C, 7.38 MPa). First industrial scale CO2 injection project: Sleipner gas field (North Sea

  9. A numerical procedure to model and monitor CO2 sequestration in aquifers

    E-Print Network [OSTI]

    Santos, Juan

    sequestration over very long periods of time. The analysis of CO2 underground storage safety in the long term procedure to model and monitor CO2 sequestration in aquifers p. #12;Introduction. I Storage of CO2 (31.6C, 7.38 MPa). First industrial scale CO2 injection project: Sleipner gas field (North Sea

  10. A multiple layer numerical model of the formation of the low-level jet

    E-Print Network [OSTI]

    Shen, Tsu-Cheng

    1980-01-01T23:59:59.000Z

    310 320 e(kj Fig. 3. The initial vertical distribution of potential tempera- ture in the model . Table 3. The vertical distribution of the variables used for setting the initial conditions. LEVEL k (m s ) kh(m s ) u(ms ) v(ms ) w(ms ) e (k) 00 p...

  11. NUMERICAL MODELLING OF MICROORGANISMS DISPERSION IN URBAN AREA: APPLICATION TO LEGIONELLA.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    with transmission of an infectious agent from cooling towers (CT). During the episode that occured in Pas to contaminated cooling towers system may occur over distance larger than 10km. In addition, most cooling towers dispersion from a virtual cooling tower at the same location. The biological model has been activated

  12. Evaluation of a semi-implicit numerical algorithm for a rate-dependent ductile failure model.

    SciTech Connect (OSTI)

    Zocher, M. A. (Marvin Anthony); Zuo, Q. K. (Qiuhai K.); Mason, T. A. (Thomas A.)

    2002-09-01T23:59:59.000Z

    A survey conducted in the mid-80's revealed that the mathematical descriptions of ductile fracture tended to apply to either tensile tests or spa11 tests. The objective behind the development of the TEPLA was then a unification of these disparate phenomena into a single model.

  13. Regional dust model performance during SAMUM 2006 K. Haustein,1

    E-Print Network [OSTI]

    established forecast model delivering daily products for North Africa, Europe, Middle East and Asia http

  14. Numerical study of three-dimensional PIC for the surface plasmon excitation based on Drude model

    E-Print Network [OSTI]

    Liu, La-Qun; Wang, Hui-Hui; Liu, Da-Gang

    2015-01-01T23:59:59.000Z

    This paper explores the time-domain equations of noble metals, in which Drude model is adopted to describe the dielectric constant, to implement three-dimensional particle-in-cell (PIC) simulations for the surface plasmon excitation with the finite-difference time-domain method (FDTD). A three-dimensional model for an electron bunch movement near the metal film is constructed, and particle-in-cell (PIC) simulations are carried out with various metal films of different thicknesses. The frequency of surface plasmon obtained from PIC simulation is agreed with that from theory. Furthermore, the surface plasmon wave properties of excitation and propagation with the metal film is summarized by PIC results.

  15. Laboratory experiments and numerical modeling of wave attenuation through artificial vegetation

    E-Print Network [OSTI]

    Augustin, Lauren Nicole

    2009-05-15T23:59:59.000Z

    ). The first hydrodynamic model developed by Price et al. (1968) simulated the effects of seaweed as a high viscous layer. Mork (1996) extended the idea of the high viscous layer and developed a theory for kelp plants that took into account not only viscous... has been validated by artificial laboratory kelp experiments for the species Laminaria Hyperborea, and is assumed appropriate for representing wave transformation and damping over submerged vegetative fields of variable depths. Mork (1996) studied...

  16. Exact theory and numeric results for short pulse ionization of simple model atom in one dimension

    E-Print Network [OSTI]

    Rokhlenko, Alexander

    2015-01-01T23:59:59.000Z

    Our exact theory for continuous harmonic perturbation of a one dimensional model atom by parametric variations of its potential is generalized for the cases when a) the atom is exposed to short pulses of an external harmonic electric field and b) the forcing is represented by short bursts of different shape changing the strength of the binding potential. This work is motivated not only by the wide use of laser pulses for atomic ionization, but also by our earlier study of the same model which successfully described the ionization dynamics in all orders, i.e. the multi-photon processes, though being treated by the non-relativistic Schr\\"odinger equation. In particular, it was shown that the bound atom cannot survive the excitation of its potential caused by any non-zero frequency and amplitude of the continuous harmonic forcing. Our present analysis found important laws of the atomic ionization by short pulses, in particular the efficiency of ionizing this model system and presumably real ones as well.

  17. Numerical modeling of a thermohydrochemical (T-H-C) coupling and the implications to radionuclide transport.

    SciTech Connect (OSTI)

    Esh, D. W.; Scheetz, B. E.

    1999-09-21T23:59:59.000Z

    Thermohydrochemical (T-H-C) processes result from the placement of heat-generating radioactive materials in unsaturated, fractured geologic materials. The placement of materials in the proposed Yucca Mountain repository will result in complex environmental conditions. Simple models are developed liking the thermohydrological effects simulated with TOUGHZ to system chemistry, with an example presented for chloride. Perturbations to near-field chemistry could have a significant impact on the migration of actinides and fission products in geologic materials. Various conceptual models to represent fractures are utilized in TOUGHZ simulations of thermohydrological processes. The simulated moisture redistribution is then coupled to simple chemical models to demonstrate the potential magnitude of T-H-C processes. The concentration of chloride in solution (returning to the engineered barrier system) is demonstrated, in extreme cases, to exceed 100,000 mg/L. The implication is that the system (typically ambient chemical and hydrological conditions) in which radionuclide transport is typically simulated and measured may be significantly different from the perturbed system.

  18. Modelling the high-energy emission from gamma-ray binaries using numerical relativistic hydrodynamics

    E-Print Network [OSTI]

    Dubus, Guillaume; Fromang, Sbastien

    2015-01-01T23:59:59.000Z

    Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to $i\\approx 35^{\\rm o}$. There is a tension between th...

  19. Performance of the Community Earth System Model | Argonne Leadership...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2011 Name of Publication Source: (SC), 2011 International Conference - High Performance Computing, Networking, Storage and Analysis Publisher: IEEE Explore Page Numbers: 1-11...

  20. Temperature-aware NBTI modeling and the impact of input vector control on performance degradation

    E-Print Network [OSTI]

    Wang, Yu

    Temperature-aware NBTI modeling and the impact of input vector control on performance degradation performance degradation in dig- ital circuits by affecting PMOS threshold voltage, is emerging as one devices and propose a novel temporal performance degradation model for digital cir- cuits considering

  1. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Kaplan Turbines

    SciTech Connect (OSTI)

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.; Dauble, Dennis D.

    2007-11-10T23:59:59.000Z

    Bio-indexing of hydroturbines is an important means to optimize passage conditions for fish by identifying operations for existing and new design turbines that minimize the probability of injury. Cost-effective implementation of bio-indexing requires the use of tools such as numerical and physical turbine models to generate hypotheses for turbine operations that can be tested at prototype scales using live fish. Numerical deterministic and stochastic blade strike models were developed for a 1:25-scale physical turbine model built by the U.S. Army Corps of Engineers for the original design turbine at McNary Dam and for prototype-scale original design and replacement minimum gap runner (MGR) turbines at Bonneville Dam's first powerhouse. Blade strike probabilities predicted by both models were comparable with the overall trends in blade strike probability observed in both prototype-scale live fish survival studies and physical turbine model using neutrally buoyant beads. The predictions from the stochastic model were closer to the experimental data than the predictions from the deterministic model because the stochastic model included more realistic consideration of the aspect of fish approaching to the leading edges of turbine runner blades. Therefore, the stochastic model should be the preferred method for the prediction of blade strike and injury probability for juvenile salmon and steelhead using numerical blade-strike models.

  2. Numerical modeling of gas migration at a proposed repository for low and intermediate level nuclear wastes at Oberbauenstock, Switzerland

    SciTech Connect (OSTI)

    Pruess, K.

    1990-03-01T23:59:59.000Z

    Hydrologic impacts of corrosive gas release from a hypothetical L/ILW nuclear waste repository at Oberbauenstock are explored by means of numerical simulation. A schematic two dimensional vertical section through the mountain is modeled with the simulator TOUGH, which describes two-phase flow of water and gas in porous and fractured media. Two reference cases are considered which represent the formations as a porous and as a fractured-porous (dual permeability) medium, respectively. Both cases predict similar and rather modest pressure increases, from ambient 10 bars to near 25 bars at the repository level. These results are to be considered preliminary because important parameters affecting two-phase flow, such as relative permeabilities of a fractured medium, are not well known at present. 24 refs., 15 figs., 5 tabs.

  3. Case Studies Comparing System Advisor Model (SAM) Results to Real Performance Data: Preprint

    SciTech Connect (OSTI)

    Blair, N.; Dobos, A.; Sather, N.

    2012-06-01T23:59:59.000Z

    NREL has completed a series of detailed case studies comparing the simulations of the System Advisor Model (SAM) and measured performance data or published performance expectations. These case studies compare PV measured performance data with simulated performance data using appropriate weather data. The measured data sets were primarily taken from NREL onsite PV systems and weather monitoring stations.

  4. BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS

    E-Print Network [OSTI]

    Boyer, Edmond

    BLACK-BOX MODELLING OF HVAC SYSTEM: IMPROVING THE PERFORMANCES OF NEURAL NETWORKS Eric FOCK Ile de La Réunion - FRANCE ABSTRACT This paper deals with neural networks modelling of HVAC systems of HVAC system can be modelled using manufacturer design data presented as derived performance maps

  5. Modeling the Performance and Energy of Storage Arrays

    E-Print Network [OSTI]

    Liu, Ling

    characteristics of the system for that workload. The key abstraction used in our analytical model is the run and power predicted by the model under the migration and layout policies of PARAID accurately match the results of a detailed simulation of the system. The analytic model allows us to identify key parameters

  6. Performance and Portability of an Air Quality Model Donald Dabdub

    E-Print Network [OSTI]

    Manohar, Rajit

    and planning for the control of air pollution episodes. The California Institute of Technology (CIT) photochemical model is one such air quality model. It is used to predict the pollution dynamics in the South Coast Air Basin of California. It has also been modified to model pollution in South Korea, Mexico

  7. Parallel 3D Finite Element Numerical Modelling of DC Electron Guns

    SciTech Connect (OSTI)

    Prudencio, E.; Candel, A.; Ge, L.; Kabel, A.; Ko, K.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; /SLAC

    2008-02-04T23:59:59.000Z

    In this paper we present Gun3P, a parallel 3D finite element application that the Advanced Computations Department at the Stanford Linear Accelerator Center is developing for the analysis of beam formation in DC guns and beam transport in klystrons. Gun3P is targeted specially to complex geometries that cannot be described by 2D models and cannot be easily handled by finite difference discretizations. Its parallel capability allows simulations with more accuracy and less processing time than packages currently available. We present simulation results for the L-band Sheet Beam Klystron DC gun, in which case Gun3P is able to reduce simulation time from days to some hours.

  8. Improving Face Recognition Performance Using a Hierarchical Bayesian Model

    E-Print Network [OSTI]

    Shikaripur Nadig, Ashwini

    2010-04-27T23:59:59.000Z

    which can result in an improved recognition performance over already existing baseline approaches. We use Kernelized Fisher Discriminant Analysis (KFLD) as our baseline as it is superior to PCA in a way that it produces well separated classes even under...

  9. Accelerating Energy Savings Performance Contracting Through Model Statewide Programs

    Broader source: Energy.gov [DOE]

    Provides information on Energy Savings Performance Contracing (ESPC), including links to best practices and tools as well as the Accelerated ESCP initiative and types of assistance available. Author: Energy Services Coalition

  10. A numerical model and scaling relationship for energetic electron beams propagating in air

    SciTech Connect (OSTI)

    Fernsler, R. F.; Slinker, S. P. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lambrakos, S. G. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2008-09-15T23:59:59.000Z

    Scaling relationships for energy loss and scattering are combined with a particle code to construct a purely algebraic expression for the energy deposited by an energetic electron beam injected into field-free homogeneous air. An algebraic formulation is possible because the mean free paths for the major collisional processes depend similarly on density and energy above 1 keV. Accordingly, the spatial behavior of an initially cold pencil beam is approximately self-similar when expressed in terms of the nominal beam range, provided the beam energy at injection exceeds several keV. Since a warm and broad beam can always be decomposed into a series of cold pencil beams, the total energy deposited can be obtained through a simple sum. With such a model, the ionization and excitation generated by a beam can be computed quickly and easily at every point in space. Similar formulations can be developed for other media using particle codes or experimental data. In liquids or solids, the energy deposited is quickly converted to heat and ultimately to melting and/or vaporization of the material.

  11. Roofline: An Insightful Visual Performance Model for Floating-Point Programs and Multicore Architectures

    SciTech Connect (OSTI)

    Williams, Samuel; Waterman, Andrew; Patterson, David

    2009-02-01T23:59:59.000Z

    We propose an easy-to-understand, visual performance model that offers insights to programmers and architects on improving parallel software and hardware for floating point computations.

  12. WUFI COMPUTER MODELING WORKSHOP FOR WALL DESIGN AND PERFORMANCE

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    , building forensic specialists, manufacturer representatives, facilities managers, IAQ specialists of modeling for new products are demonstrated by both group and individual interaction. You will learn how

  13. Methodology for Modeling Building Energy Performance across the Commercial Sector

    SciTech Connect (OSTI)

    Griffith, B.; Long, N.; Torcellini, P.; Judkoff, R.; Crawley, D.; Ryan, J.

    2008-03-01T23:59:59.000Z

    This report uses EnergyPlus simulations of each building in the 2003 Commercial Buildings Energy Consumption Survey (CBECS) to document and demonstrate bottom-up methods of modeling the entire U.S. commercial buildings sector (EIA 2006). The ability to use a whole-building simulation tool to model the entire sector is of interest because the energy models enable us to answer subsequent 'what-if' questions that involve technologies and practices related to energy. This report documents how the whole-building models were generated from the building characteristics in 2003 CBECS and compares the simulation results to the survey data for energy use.

  14. Mathematical and numerical studies of nonstandard difference equation models of differential equations. Final technical report, September 1995--September 1997

    SciTech Connect (OSTI)

    Mickens, R.E.

    1997-12-12T23:59:59.000Z

    The major thrust of this proposal was to continue our investigations of so-called non-standard finite-difference schemes as formulated by other authors. These schemes do not follow the standard rules used to model continuous differential equations by discrete difference equations. The two major aspects of this procedure consist of generalizing the definition of the discrete derivative and using a nonlocal model (on the computational grid or lattice) for nonlinear terms that may occur in the differential equations. Our aim was to investigate the construction of nonstandard finite-difference schemes for several classes of ordinary and partial differential equations. These equations are simple enough to be tractable, yet, have enough complexity to be both mathematically and scientifically interesting. It should be noted that all of these equations differential equations model some physical phenomena under an appropriate set of experimental conditions. The major goal of the project was to better understand the process of constructing finite-difference models for differential equations. In particular, it demonstrates the value of using nonstandard finite-difference procedures. A secondary goal was to construct and study a variety of analytical techniques that can be used to investigate the mathematical properties of the obtained difference equations. These mathematical procedures are of interest in their own right and should be a valuable contribution to the mathematics research literature in difference equations. All of the results obtained from the research done under this project have been published in the relevant research/technical journals or submitted for publication. Our expectation is that these results will lead to improved finite difference schemes for the numerical integration of both ordinary and partial differential equations. Section G of the Appendix gives a concise summary of the major results obtained under funding by the grant.

  15. ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS

    SciTech Connect (OSTI)

    Chiswell, S

    2009-01-11T23:59:59.000Z

    Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.

  16. Personal Computer-Based Model for Cool Storage Performance Simulation

    E-Print Network [OSTI]

    Kasprowicz, L. M.; Jones, J. W.; Hitzfelder, J.

    1990-01-01T23:59:59.000Z

    A personal computer based hourly simulation model was developed based on the CBS/ICE routines in the DOE-2.1 mainframe building simulation software. The menu driven new model employs more efficient data and information handling than the previous...

  17. Modeling the Impact of Product Portfolio on the Economic and Environmental Performance of Recycling Systems

    E-Print Network [OSTI]

    Dahmus, Jeffrey B.

    hrough the development of a general model of electronics recycling systems, the effect of product portfolio choices on economic and environmental system performance is explored. The general model encompasses the three main ...

  18. An Analytic Model for ATM Network Performance and its Application to BSP

    E-Print Network [OSTI]

    Graham, Nick

    as networks of workstations, and may become the standard mechanism for interconnecting processors at all the model is simple, there is substantial agreement with measured results where these are known computing, interconnection network, performance modelling, total exchange, bulk synchronous parallelism

  19. An Analytic Model for ATM Network Performance and its Application to BSP

    E-Print Network [OSTI]

    Graham, Nick

    as networks of workstations, and may become the standard mechanism for interconnecting processors at all the model is simple, there is substantial agreement with measured results where these are known: parallel computing, interconnection network, performance modelling, total exchange, bulk synchronous

  20. An improved structural mechanics model for the FRAPCON nuclear fuel performance code

    E-Print Network [OSTI]

    Mieloszyk, Alexander James

    2012-01-01T23:59:59.000Z

    In order to provide improved predictions of Pellet Cladding Mechanical Interaction (PCMI) for the FRAPCON nuclear fuel performance code, a new model, the FRAPCON Radial-Axial Soft Pellet (FRASP) model, was developed. This ...

  1. Hybrid Model for Building Performance Diagnosis and Optimal Control

    E-Print Network [OSTI]

    Wang, S.; Xu, X.

    2003-01-01T23:59:59.000Z

    simulation model is based on first principles, either a detailed first principles model, such as EnergyPlus (Crawley and Drury 2000), DOE-2 (Ed Kidd et al. 2001), or a simplified first principles model, such as AIRMODEL (Giebler et al. 1998) which....D. (1999). Whole building diagnostics. http://poet.lbl.gov/diagworkshop/proceedings Crawley, Drury B. (2000). EnergyPlus: energy simulation program; ASHRAE Journal Apr 2000; Vol. 42(4):49-56. Davis L. (1991). Handbook of genetic algorithms. New...

  2. Analytical model and performance data for a cylindrical parabolic collector

    SciTech Connect (OSTI)

    Ford, F.M.; Stewart, W.E. Jr.

    1980-01-01T23:59:59.000Z

    Concentrating solar collectors provide higher fluid temperatures than flat-plate, an important advantage in many applications. The parabolic cylinder is one of the most popular types of concentrating collectors because of its relatively simple construction and tracking configuration. A mathematical model was developed for one such collector in order to predict thermal efficiency as a function of solar insolation. An experiment was then devised in an attempt to verify this model. Discrepancies between predicted and observed values are discussed, and suggestions are made for improving the model and the experimental procedure.

  3. Modeling performance of horizontal, undulating, and multilateral wells

    E-Print Network [OSTI]

    Kamkom, Rungtip

    2009-05-15T23:59:59.000Z

    .....................................................................................................1 1.2 Literature Review............................................................................................2 1.3 Objectives........................................................................................................4 1.4...........................................................18 2.3 Two-Phase Reservoirs...................................................................................21 2.4 Systematic Table for Horizontal Well Inflow Performance..........................22 2.5 Wellbore Pressure Drop...

  4. OPTIMIZATION AND PERFORMANCE MODELING OF STENCIL COMPUTATIONS ON MODERN MICROPROCESSORS

    E-Print Network [OSTI]

    (PDE) solvers constitute a large fraction of scientific applications in such diverse areas as heat- tive finite-difference techniques, which sweep over a spatial grid, performing nearest neighbor the coefficients of the PDE for that data element. These operations are then used to build solvers that range from

  5. Fuel Cell Power Model for CHHP System Economics and Performance...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Cell Tri-Generation System Case Study using the H2A Stationary Model Tri-Generation Success Story: World's First Tri-Gen Energy Station-Fountain Valley Biogas Opportunities Roadmap...

  6. Summary Results for Brine Migration Modeling Performed by LANL...

    Energy Savers [EERE]

    in a High Level Waste Repository in Salt Establishing the Technical Basis for Disposal of Heat-generating Waste in Salt Model Development and Analysis of the Fate and Transport of...

  7. A Comparison of HCCI Engine Performance Data and Kinetic Modeling...

    Broader source: Energy.gov (indexed) [DOE]

    - Better chance to predict emissions CFD model - Most true to flow, mixing, and heat loss processes 5 Managed by UT-Battelle for the Department of Energy ORNL HCCI engine...

  8. Linking RESRAD-OFFSITE and HYDROGEOCHEM Model for Performance Assessment of Low-Level Radioactive Waste Disposal Facility - 13429

    SciTech Connect (OSTI)

    Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taiwan (China)] [Hydrotech Research Institute, National Taiwan University, Taiwan (China); Yu, Charley; Cheng, Jing-Jy; Kamboj, Sunita; Gnanapragasam, Emmanuel [Argonne National Laboratory, Argonne, IL 60439 (United States)] [Argonne National Laboratory, Argonne, IL 60439 (United States); Liu, Chen-Wuing [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China)] [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)] [Institute of Hydrological and Oceanic Sciences, National Central University, Taiwan (China)

    2013-07-01T23:59:59.000Z

    Performance assessments are crucial steps for the long-term radiological safety requirements of low-level waste (LLW) disposal facility. How much concentration of radionuclides released from the near-field to biosphere and what radiation exposure levels of an individual can influence on the satisfactory performance of the LLW disposal facility and safety disposal environment. Performance assessment methodology for the radioactive waste disposal consists of the reactive transport modeling of safety-concerned radionuclides released from the near-field to the far-field, and the potential exposure pathways and the movements of radionuclides through the geosphere, biosphere and man of which the accompanying dose. Therefore, the integration of hydrogeochemical transport model and dose assessment code, HYDROGEOCHEM code and RESRAD family of codes is imperative. The RESRAD family of codes such as RESRAD-OFFSITE computer code can evaluate the radiological dose and excess cancer risk to an individual who is exposed while located within or outside the area of initial (primary) contamination. The HYDROGEOCHEM is a 3-D numerical model of fluid flow, thermal, hydrologic transport, and biogeochemical kinetic and equilibrium reactions in saturated and unsaturated media. The HYDROGEOCHEM model can also simulate the crucial geochemical mechanism, such as the effect of redox processes on the adsorption/desorption, hydrogeochemical influences on concrete degradation, adsorption/desorption of radionuclides (i.e., surface complexation model) between solid and liquid phase in geochemically dynamic environments. To investigate the safety assessment of LLW disposal facility, linking RESRAD-OFFSITE and HYDROGEOCHEM model can provide detailed tools of confidence in the protectiveness of the human health and environmental impact for safety assessment of LLW disposal facility. (authors)

  9. Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models

    E-Print Network [OSTI]

    1 Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models distilled from measure data, rather than models derived from transformer heat for measuring the acceptability of transformer thermal models. For a model to be acceptable, it must have

  10. Do Some Business Models Perform Better than Others? A Study of the 1000 Largest US

    E-Print Network [OSTI]

    Do Some Business Models Perform Better than Others? A Study of the 1000 Largest US Firms Authors, the concept of business model remains seldom studied. This paper begins by defining a business model as what of business models (Creators, Distributors, Landlords and Brokers). Next, by considering the type of asset

  11. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Peace, Gerald L.; Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2005-11-01T23:59:59.000Z

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses. At least one-hundred realizations were simulated for each scenario defined in the performance assessment. Conservative values and assumptions were used to define values and distributions of uncertain input parameters when site data were not available. Results showed that exposure to tritium via the air pathway exceeded the regulatory metric of 10 mrem/year in about 2% of the simulated realizations when the receptor was located at the MWL (continuously exposed to the air directly above the MWL). Simulations showed that peak radon gas fluxes exceeded the design standard of 20 pCi/m{sup 2}/s in about 3% of the realizations if up to 1% of the containers of sealed radium-226 sources were assumed to completely degrade in the future. If up to 100% of the containers of radium-226 sources were assumed to completely degrade, 30% of the realizations yielded radon surface fluxes that exceeded the design standard. For the groundwater pathway, simulations showed that none of the radionuclides or heavy metals (lead and cadmium) reached the groundwater during the 1,000-year evaluation period. Tetrachloroethylene (PCE) was used as a proxy for other VOCs because of its mobility and potential to exceed maximum contaminant levels in the groundwater relative to other VOCs. Simulations showed that PCE reached the groundwater, but only 1% of the realizations yielded aquifer concentrations that exceeded the regulatory metric of 5 {micro}g/L. Based on these results, monitoring triggers have been proposed for the air, surface soil, vadose zone, and groundwater at the MWL. Specific triggers include numerical thresholds for radon concentrations in the air, tritium concentrations in surface soil, infiltration through the vadose zone, and uranium and select VOC concentrations in groundwater. The proposed triggers are based on U.S. Environmental Protection Agency and Department of Energy regulatory standards. If a trigger is exceeded, then a trigger evaluation process will be initiated which will allow sufficient data to be collected to assess trends and recommend corrective actions, if necessary.

  12. Design of a Multicriteria Performance Model for JIT systems

    E-Print Network [OSTI]

    Coulibaly, Soma

    1988-01-01T23:59:59.000Z

    . Afiesimama Performance measurement systems are necessary to provide a problem-f inding and problem-solving pr ocess that will motivate people to make improvements. Recently, many productivity measurement methods have been developed. However, most of them... concentrate either on the utilization of resources or the perfor mance of employees without analyzing the simultaneous impact of the environment of production, the method of production, the people involved in the production of the product...

  13. Resource Sharing in Performance Models Vlastimil Babka, Martin Decky, and Petr Tuma

    E-Print Network [OSTI]

    observed during the relatively isolated execution of benchmarks. Unless resource sharing is described shared resources [16,17,18,26,27,29] or points out the high cost of solving the performance model whenResource Sharing in Performance Models Vlastimil Babka, Martin Decky, and Petr Tuma Department

  14. Development of a High-Performance Office Building Simulation Model for a Hot and Humid Climate

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    2009-01-01T23:59:59.000Z

    applicable to office buildings in hot and humid climates and to develop a high-performance (maximum energy-efficient) building model that only uses technologies readily available in the contemporary market. The high-performance model showed 48% total energy...

  15. A Cognitively Bounded Rational Analysis Model of Dual-Task Performance Trade-Offs

    E-Print Network [OSTI]

    Saunders, Mark

    A Cognitively Bounded Rational Analysis Model of Dual-Task Performance Trade-Offs Christian P of interleaving two tasks can be described as making trade-offs between performance on each of the tasks. This can. An objective payoff function was used to describe how participants should trade-off performance between

  16. Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,*

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    1 Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,* , Kisup Leeb ventilation systems for buildings requires a suitable tool to assess the system performance-scale experimental, multizone network, zonal, and CFD) for predicting ventilation performance in buildings, which can

  17. Modeling the Logistics Performance in Developing Countries: An exploratory study of Moroccan context

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    1 Modeling the Logistics Performance in Developing Countries: An exploratory study of Moroccan to raise their levels of logistics performance. This article is a research progress; it presents, Technological Practices, Supply Chain performance, Morocco. 1. INTRODUCTION: Logistic in Morocco is still

  18. FRAPCON-3: Modifications to fuel rod material properties and performance models for high-burnup application

    SciTech Connect (OSTI)

    Lanning, D.D.; Beyer, C.E.; Painter, C.L.

    1997-12-01T23:59:59.000Z

    This volume describes the fuel rod material and performance models that were updated for the FRAPCON-3 steady-state fuel rod performance code. The property and performance models were changed to account for behavior at extended burnup levels up to 65 Gwd/MTU. The property and performance models updated were the fission gas release, fuel thermal conductivity, fuel swelling, fuel relocation, radial power distribution, solid-solid contact gap conductance, cladding corrosion and hydriding, cladding mechanical properties, and cladding axial growth. Each updated property and model was compared to well characterized data up to high burnup levels. The installation of these properties and models in the FRAPCON-3 code along with input instructions are provided in Volume 2 of this report and Volume 3 provides a code assessment based on comparison to integral performance data. The updated FRAPCON-3 code is intended to replace the earlier codes FRAPCON-2 and GAPCON-THERMAL-2. 94 refs., 61 figs., 9 tabs.

  19. Modeling Windows in Energy Plus with Simple Performance Indices

    E-Print Network [OSTI]

    indices (U-factor, Solar Heat Gain Coefficient, and Visible Transmittance) to model the energy impacts, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily

  20. A Linear Parabolic Trough Solar Collector Performance Model

    E-Print Network [OSTI]

    Qu, M.; Archer, D.; Masson, S.

    2006-01-01T23:59:59.000Z

    through a 6m by 2.3m PTSC with 900 w/m^2 solar insulation and 0 incident angle, the estimated collector efficiency is about 55% The model predictions will be confirmed by the operation of PTSCs now being installed at Carnegie Mellon....

  1. A Microcomputer Model of Crossflow Cooling Tower Performance

    E-Print Network [OSTI]

    Reichelt, G. E; Jones, J. W.

    1984-01-01T23:59:59.000Z

    that use both sensible heat transfer and mass transfer to cool. The heat and mass transfer process for a crossflow cooling tower has been modeled on an Apple II microcomputer. Various heat loads or weather conditions can be imposed on a given tower...

  2. A NEW MODEL FOR PERFORMANCE PREDICTION OF HARD ROCK TBMS.

    E-Print Network [OSTI]

    TBMs. The model uses information on the rock properties and cutting geometry to calculate TBM rate on data collected in the field and is merely a regression between machine parameters, rock properties is introduced to provide an estimate of disc cutting forces as a function of rock properties and the cutting

  3. 11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole

    E-Print Network [OSTI]

    Boyer, Edmond

    11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole moments of polarizable of the induced multipole moments. A general multipole theory is available in the literature, however, only linear multipole model is usually exploited when determining numerically these effective moments. Since this axial

  4. Numerical modeling of elution peak profiles in supercritical fluid chromatography. Part I-Elution of an unretained tracer

    SciTech Connect (OSTI)

    Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL

    2010-01-01T23:59:59.000Z

    When chromatography is carried out with high-density carbon dioxide as the main component of the mobile phase (a method generally known as 'supercritical fluid chromatography' or SFC), the required pressure gradient along the column is moderate. However, this mobile phase is highly compressible and, under certain experimental conditions, its density may decrease significantly along the column. Such an expansion absorbs heat, cooling the column, which absorbs heat from the outside. The resulting heat transfer causes the formation of axial and radial gradients of temperature that may become large under certain conditions. Due to these gradients, the mobile phase velocity and most physico-chemical parameters of the system (viscosity, diffusion coefficients, etc.) are no longer constant throughout the column, resulting in a loss of column efficiency, even at low flow rates. At high flow rates and in serious cases, systematic variations of the retention factors and the separation factors with increasing flow rates and important deformations of the elution profiles of all sample components may occur. The model previously used to account satisfactorily for the effects of the viscous friction heating of the mobile phase in HPLC is adapted here to account for the expansion cooling of the mobile phase in SFC and is applied to the modeling of the elution peak profiles of an unretained compound in SFC. The numerical solution of the combined heat and mass balance equations provides temperature and pressure profiles inside the column, and values of the retention time and efficiency for elution of this unretained compound that are in excellent agreement with independent experimental data.

  5. Age-aware solder performance models : level 2 milestone completion.

    SciTech Connect (OSTI)

    Neilsen, Michael K.; Vianco, Paul Thomas; Neidigk, Matthew Aaron; Holm, Elizabeth Ann

    2010-09-01T23:59:59.000Z

    Legislated requirements and industry standards are replacing eutectic lead-tin (Pb-Sn) solders with lead-free (Pb-free) solders in future component designs and in replacements and retrofits. Since Pb-free solders have not yet seen service for long periods, their long-term behavior is poorly characterized. Because understanding the reliability of Pb-free solders is critical to supporting the next generation of circuit board designs, it is imperative that we develop, validate and exercise a solder lifetime model that can capture the thermomechanical response of Pb-free solder joints in stockpile components. To this end, an ASC Level 2 milestone was identified for fiscal year 2010: Milestone 3605: Utilize experimentally validated constitutive model for lead-free solder to simulate aging and reliability of solder joints in stockpile components. This report documents the completion of this milestone, including evidence that the milestone completion criteria were met and a summary of the milestone Program Review.

  6. Atmospheric Climate Model Experiments Performed at Multiple Horizontal Resolutions

    SciTech Connect (OSTI)

    Phillips, T; Bala, G; Gleckler, P; Lobell, D; Mirin, A; Maxwell, R; Rotman, D

    2007-12-21T23:59:59.000Z

    This report documents salient features of version 3.3 of the Community Atmosphere Model (CAM3.3) and of three climate simulations in which the resolution of its latitude-longitude grid was systematically increased. For all these simulations of global atmospheric climate during the period 1980-1999, observed monthly ocean surface temperatures and sea ice extents were prescribed according to standard Atmospheric Model Intercomparison Project (AMIP) values. These CAM3.3 resolution experiments served as control runs for subsequent simulations of the climatic effects of agricultural irrigation, the focus of a Laboratory Directed Research and Development (LDRD) project. The CAM3.3 model was able to replicate basic features of the historical climate, although biases in a number of atmospheric variables were evident. Increasing horizontal resolution also generally failed to ameliorate the large-scale errors in most of the climate variables that could be compared with observations. A notable exception was the simulation of precipitation, which incrementally improved with increasing resolution, especially in regions where orography plays a central role in determining the local hydroclimate.

  7. Accounting for the effects of rehabilitation actions on the reliability of flexible pavements: performance modeling and optimization

    E-Print Network [OSTI]

    Deshpande, Vighnesh Prakash

    2009-05-15T23:59:59.000Z

    A performance model and a reliability-based optimization model for flexible pavements that accounts for the effects of rehabilitation actions are developed. The developed performance model can be effectively implemented in all the applications...

  8. Grid-Based Surrogate Reservoir Modeling (SRM) for Fast Track Analysis of Numerical Reservoir Simulation Models at the Grid block Level

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    with a large number of producers, second, to a CO2 sequestration project in Australia, and finally to a numerical simulation study of potential carbon storage site in the United States. The numerical reservoir

  9. Sensitivity of Concentrating Solar Power Trough Performance, Cost and Financing with Solar Advisor Model

    SciTech Connect (OSTI)

    Blair, N.; Mehos, M.; Christensen, C.

    2008-03-01T23:59:59.000Z

    A comprehensive solar technology systems analysis model, the Solar Advisor Model (SAM) was developed to support the federal R&D community and the solar industry. This model, developed by staff at NREL and Sandia National Laboratory, is able to model the costs, finances, and performance of concentrating solar power and photovoltaics (PV). Currently, parabolic troughs and concentrating PV are the two concentrating technologies modeled within the SAM environment.

  10. Sandia Energy - PV Performance Modeling Collaborative's New and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol Home Distribution Grid IntegrationOffshore Wind RD&D:PV Modeling

  11. Modeling Photovoltaic and Concentrating Solar Power Trough Performance, Cost, and Financing with the Solar Advisor Model: Preprint

    SciTech Connect (OSTI)

    Blair, N.; Mehos, M.; Christensen, C.; Cameron, C.

    2008-05-01T23:59:59.000Z

    A comprehensive solar technology systems analysis model, the Solar Advisor Model (SAM), has been developed to support the federal R&D community and the solar industry by staff at the National Renewable Energy Laboratory (NREL) and Sandia National Laboratory. This model is able to model the finances, incentives, and performance of flat-plate photovoltaic (PV), concentrating PV, and concentrating solar power (specifically, parabolic troughs). The primary function of the model is to allow users to investigate the impact of variations in performance, cost, and financial parameters to better understand their impact on key figures of merit. Figures of merit related to the cost and performance of these systems include, but aren't limited to, system output, system efficiencies, levelized cost of energy, return on investment, and system capital and O&M costs. There are several models within SAM to model the performance of photovoltaic modules and inverters. This paper presents an overview of each PV and inverter model, introduces a new generic model, and briefly discusses the concentrating solar power (CSP) parabolic trough model. A comparison of results using the different PV and inverter models is also presented.

  12. Results and Comparison from the SAM Linear Fresnel Technology Performance Model: Preprint

    SciTech Connect (OSTI)

    Wagner, M. J.

    2012-04-01T23:59:59.000Z

    This paper presents the new Linear Fresnel technology performance model in NREL's System Advisor Model. The model predicts the financial and technical performance of direct-steam-generation Linear Fresnel power plants, and can be used to analyze a range of system configurations. This paper presents a brief discussion of the model formulation and motivation, and provides extensive discussion of the model performance and financial results. The Linear Fresnel technology is also compared to other concentrating solar power technologies in both qualitative and quantitative measures. The Linear Fresnel model - developed in conjunction with the Electric Power Research Institute - provides users with the ability to model a variety of solar field layouts, fossil backup configurations, thermal receiver designs, and steam generation conditions. This flexibility aims to encompass current market solutions for the DSG Linear Fresnel technology, which is seeing increasing exposure in fossil plant augmentation and stand-alone power generation applications.

  13. 2/27/2001 Systems Modeling -Spring 2001 1 Availability and Performability

    E-Print Network [OSTI]

    Browne, James C.

    2/27/2001 Systems Modeling - Spring 2001 1 Availability and Performability Coverage Definitions Rates Representations Examples #12;2/27/2001 Systems Modeling - Spring 2001 2 Availability can be computed from a state model where each state is a configuration of the system. #12;2/27/2001

  14. Performance Assessment of Different Control Structures for Generic Reactive Distillation Using Linear and Nonlinear Process Models

    E-Print Network [OSTI]

    Al-Arfaj, Muhammad A.

    compares the closed-loop performance of three control structures using an approximate linear model. Responses based on the linear model for various control structures show a good agreement when compared of the linear model is shown to be better in a single-end control system than in a dual-end control system

  15. Development of a High-Performance Office Building Simulation Model for a Hot and Humid Climate

    E-Print Network [OSTI]

    Cho, S.; Haberl, J.

    -performance measures applicable to office buildings in hot and humid climates and to develop a high-performance (maximum energy-efficient) building model that only uses technologies readily available in the contemporary market. The high-performance model showed... requirements. This base-case model consumed a total of 7,721 GJ/yr. As shown in Figure 22, the implementation of occupancy sensors impacted the energy consumption the most, saving 11.2% of the total energy consumption. By this measure, indoor lights were...

  16. Numerical failure analysis of a stretch-bending test on dual-phase steel sheets using a phenomenological fracture model

    E-Print Network [OSTI]

    Luo, Meng

    Advanced High Strength Steels (AHSS) are increasingly used in automotive industry due to their superior strength and substantial weight advantage. However, their compromised ductility gives rise to numerous manufacturing ...

  17. A Study to Verify the Material Surface Concept of Water Table by Examining Analytical and Numerical Models.

    E-Print Network [OSTI]

    Dadi, Sireesh Kumar

    2011-10-21T23:59:59.000Z

    and both the numerical and the analytical results were compared with a 7-day, constant rate pumping test conducted by University of Waterloo researchers at Canadian Air Force Base Borden in Ontario, Canada....

  18. Improvement of capabilities of the Distributed Electrochemistry Modeling Tool for investigating SOFC long term performance

    SciTech Connect (OSTI)

    Gonzalez Galdamez, Rinaldo A.; Recknagle, Kurtis P.

    2012-04-30T23:59:59.000Z

    This report provides an overview of the work performed for Solid Oxide Fuel Cell (SOFC) modeling during the 2012 Winter/Spring Science Undergraduate Laboratory Internship at Pacific Northwest National Laboratory (PNNL). A brief introduction on the concept, operation basics and applications of fuel cells is given for the general audience. Further details are given regarding the modifications and improvements of the Distributed Electrochemistry (DEC) Modeling tool developed by PNNL engineers to model SOFC long term performance. Within this analysis, a literature review on anode degradation mechanisms is explained and future plans of implementing these into the DEC modeling tool are also proposed.

  19. Performance of Assisted History Matching Techniques When Utilizing Multiple Initial Geologic Models

    E-Print Network [OSTI]

    Aggarwal, Akshay

    2011-11-15T23:59:59.000Z

    the geological information, and performed petrophysical log evaluation along with well test data calibration. The ensemble of static models obtained was carried through the AHM methodology. I used sensitivity analysis to determine the most important dynamic...

  20. Microsoft Word - NRAP-TRS-III-002-2012_Modeling the Performance...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling the Performance of Large- Scale CO 2 Storage Systems: A Comparison of Different Sensitivity Analysis Methods 24 October 2012 Office of Fossil Energy NRAP-TRS-III-002-2012...

  1. Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

    DOE Patents [OSTI]

    Gering, Kevin L

    2013-08-27T23:59:59.000Z

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

  2. Thermal mass performance in residential construction : an energy analysis using a cube model

    E-Print Network [OSTI]

    Ledwith, Alison C. (Alison Catherine)

    2012-01-01T23:59:59.000Z

    Given the pervasiveness of energy efficiency concerns in the built environment, this research aims to answer key questions regarding the performance of thermal mass construction. The work presents the Cube Model, a simplified ...

  3. Design optimization and analysis of coated particle fuel using advanced fuel performance modeling techniques

    E-Print Network [OSTI]

    Soontrapa, Chaiyod

    2005-01-01T23:59:59.000Z

    Modifying material properties provides another approach to optimize coated particle fuel used in pebble bed reactors. In this study, the MIT fuel performance model (TIMCOAT) was applied after benchmarking against the ...

  4. Genetic icing effects on forward flight performance of a model helicopter rotor

    E-Print Network [OSTI]

    Tinetti-Sanchez, Ana Fiorella

    1987-01-01T23:59:59.000Z

    GENERIC ICING EFFECTS ON FORWARD FLIGHT PERFORMANCE OF A MODEL HELICOPTER ROTOR A Thesis ANA FIORELLA TINETTI-SANCHEZ Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1987 Major Subject: Aerospace Engineering GENERIC ICING EFFECTS ON FORWARD FLIGHT PERFORMANCE OF A MODEL HELICOPTER ROTOR A Thesis by ANA FIORELLA TINETTI-SANCHEZ Approved as to style and content by: Kenneth D. Korkan...

  5. Development of a new model for predicting sucker-rod pumping system performance

    E-Print Network [OSTI]

    Garcia, Julian Perez

    1988-01-01T23:59:59.000Z

    DEVELOPMENT OF A NEW MODEL FOR PREDICTING SUCKER-ROD PUMPING SYSTEM PERFORMANCE A Thesis by JULIAN PEREZ GARCIA, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1988 Major Subject: Petroleum Engineering DEVELOPMENT OF A NEW MODEL FOR PREDICTING SUCKER-ROD PUMPING SYSTEM PERFORMANCE A Thesis by JULIAN PEREZ GARCIA, JR. Approved as to style and content by: J. . Jen in s (Cha...

  6. Modeling the performance of high burnup thoria and urania PWR fuel

    E-Print Network [OSTI]

    Long, Yun, 1972-

    2002-01-01T23:59:59.000Z

    Fuel performance models have been developed to assess the performance of ThO?-UO? fuels that can be operated to a high burnup up to 80-100MWd/kgHM in current and future Light Water Reactors (LWRs). Among the various issues ...

  7. Modeling and evaluating the performance of Brillouin distributed optical fiber sensors

    E-Print Network [OSTI]

    Dalang, Robert C.

    Modeling and evaluating the performance of Brillouin distributed optical fiber sensors Marcelo A analysis of the key factors impacting on the performance of Brillouin distributed optical fiber sensors of America OCIS codes: (060.2310) Fiber optics; (060.2370) Fiber optics sensors; (290.5900) Scattering

  8. A HUMAN PERFORMANCE MODEL OF COMMERCIAL JETLINER TAXIING Michael D. Byrne, Jeffrey C. Zemla

    E-Print Network [OSTI]

    Byrne, Mike

    performance between large-scale engineering-oriented simulations and human-in-the-loop experiments. In order are limited in several ways. One common method is to employ human-in-the-loop (HITL) experiments. In orderA HUMAN PERFORMANCE MODEL OF COMMERCIAL JETLINER TAXIING Michael D. Byrne, Jeffrey C. Zemla Rice

  9. Embedded Markov Process based Model for Performance Analysis of Intrusion Detection and

    E-Print Network [OSTI]

    Boutaba, Raouf

    and evaluates its impact on performance. Through extensive simulations, we validate the proposed model-off between security enforcement levels on one side and network Quality of Service (QoS) requirements on the other. Index Terms--Security Performance Evaluation, Intrusion De- tection and Prevention Systems

  10. Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models

    SciTech Connect (OSTI)

    Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences

    2013-11-13T23:59:59.000Z

    We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.

  11. Specifications for the development of a fully three-dimensional numerical groundwater model for regional mass transport of radionuclides from a deep waste repository

    SciTech Connect (OSTI)

    Prickett, T.A.

    1980-04-01T23:59:59.000Z

    Specifications are given which are necessary to develop a three-dimensional numerical model capable of simulating regional mass transport of radionuclides from a deep waste repository. The model to be developed will include all of the significant mass transport processes including flow, chemical, and thermal advection, mechanical dispersion, molecular diffusion, ion exchange reactions, and radioactive decay. The model specifications also include that density and viscosity fluid properties be functions of pressure, temperature, and concentration and take into account fluid and geologic heterogenieties by allowing possible assignment of individual values to every block of the model. The model specifications furthermore include the repository shape, input/output information, boundary conditions, and the need for documentation and a user's manual. Model code validation can be accomplished with the included known analytical or laboratory solutions. It is recommended that an existing finite-difference model (developed by INTERCOMP and INTERA, Inc.) be used as a starting point either as an acceptable basic code for modification or as a pattern for the development of a completely different numerical scheme. A ten-step plan is given to outline the general procedure for development of the code.

  12. Long-term performance of ceramic matrix composites at elevated temperatures: Modelling of creep and creep rupture

    SciTech Connect (OSTI)

    Curtin, W.A.; Fabeny, B.; Ibnabdeljalil, M.; Iyengar, N.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Engineering Science and Mechanics

    1996-07-31T23:59:59.000Z

    The models developed, contain explicit dependences on constituent material properties and their changes with time, so that composite performance can be predicted. Three critical processes in ceramic composites at elevated temperatures have been modeled: (1) creep deformation of composite vs stress and time-dependent creep of fibers and matrix, and failure of these components; (2) creep deformation of ``interface`` around broken fibers; and (3) lifetime of the composite under conditions of fiber strength loss over time at temperature. In (1), general evolution formulas are derived for relaxation time of matrix stresses and steady-state creep rate of composite; the model is tested against recent data on Ti-MMCs. Calculations on a composite of Hi-Nicalon fibers in a melt-infiltrated SiC matrix are presented. In (2), numerical simulations of composite failure were made to map out time-to-failure vs applied load for several sets of material parameters. In (3), simple approximate relations are obtained between fiber life and composite life that should be useful for fiber developers and testers. Strength degradation data on Hi-Nicalon fibers is used to assess composite lifetime vs fiber lifetime for Hi-Nicalon fiber composites.

  13. PERFORMANCE VERIFICATION OF DISCRETE EVENT SYSTEMS USING HYBRID MODEL-CHECKING

    E-Print Network [OSTI]

    Boyer, Edmond

    of the plant with a timed discrete model of the controller. We will also show, using a basic examplePERFORMANCE VERIFICATION OF DISCRETE EVENT SYSTEMS USING HYBRID MODEL-CHECKING Bruno Denis (1 Systems (DES) and Hybrid Dynamic Systems (HDS) are quite substantial, especially as regards the controller

  14. PAVEMENT PREDICTION PERFORMANCE MODELS AND RELATION WITH TRAFFIC FATALITIES AND INJURIES

    E-Print Network [OSTI]

    Boyer, Edmond

    PAVEMENT PREDICTION PERFORMANCE MODELS AND RELATION WITH TRAFFIC FATALITIES AND INJURIES V. CEREZO.gothie@developpement-durable.gouv.fr ABSTRACT This paper presents some results of a study, which aimed at modelling pavement evolution, pavement characteristics and age. In a second part, non-linear regressions were used in view of obtaining

  15. ASES Proc. Solar 2010, Phoenix, AZ HIGH PERFORMANCE MSG SATELLITE MODEL FOR OPERATIONAL

    E-Print Network [OSTI]

    Perez, Richard R.

    ENERGY APPLICATIONS Toms Cebecauer GeoModel, s.r.o. Pionierska 15 841 07 Bratislava, Slovakia tomas terrain affects exploitation of solar energy. In this article we present innovative features of MSG ASES Proc. Solar 2010, Phoenix, AZ HIGH PERFORMANCE MSG SATELLITE MODEL FOR OPERATIONAL SOLAR

  16. Integrated Estimation and Tracking of Performance Model Parameters with Autoregressive Trends

    E-Print Network [OSTI]

    Woodside, C. Murray

    1 Integrated Estimation and Tracking of Performance Model Parameters with Autoregressive Trends Tao the model parameters can be tracked by an estimator such as a Kalman Filter, so that decisions can excessive cost (as is usually the case for the CPU time of a service). Because there may be significant

  17. Adaptation and Validation of an Agent Model of Functional State and Performance for Individuals

    E-Print Network [OSTI]

    Treur, Jan

    functional state model to the individual and validation of the resulting model. First, human experiments have mostly qualitative theories from Psychology, but was not validated yet using human experiments been performed by taking a number of steps. First of all, an experiment with 31 human subjects has been

  18. Observational Learning of a Bimanual Coordination Task: Understanding Movement Feature Extraction, Model Performance Level, and Perspective Angle

    E-Print Network [OSTI]

    Dean, Noah J.

    2010-07-14T23:59:59.000Z

    offset between the two hands. Video recordings of two models practicing over three days were used to make three videos for the study; an expert performance, discovery performance, and instruction performance video. The discovery video portrayed a decrease...

  19. A Distributed Electrochemistry Modeling Tool for Simulating SOFC Performance and Degradation

    SciTech Connect (OSTI)

    Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

    2011-10-13T23:59:59.000Z

    This report presents a distributed electrochemistry (DEC) model capable of investigating the electrochemistry and local conditions with the SOFC MEA based on the local microstructure and multi-physics. The DEC model can calculate the global current-voltage (I-V) performance of the cell as determined by the spatially varying local conditions through the thickness of the electrodes and electrolyte. The simulation tool is able to investigate the electrochemical performance based on characteristics of the electrode microstructure, such as particle size, pore size, electrolyte and electrode phase volume fractions, and triple-phase-boundary length. It can also investigate performance as affected by fuel and oxidant gas flow distributions and other environmental/experimental conditions such as temperature and fuel gas composition. The long-term objective for the DEC modeling tool is to investigate factors that cause electrode degradation and the decay of SOFC performance which decrease longevity.

  20. Systems, methods and computer-readable media to model kinetic performance of rechargeable electrochemical devices

    DOE Patents [OSTI]

    Gering, Kevin L.

    2013-01-01T23:59:59.000Z

    A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics. The computing system also analyzes the cell information of the electrochemical cell with a Butler-Volmer (BV) expression modified to determine exchange current density of the electrochemical cell by including kinetic performance information related to pulse-time dependence, electrode surface availability, or a combination thereof. A set of sigmoid-based expressions may be included with the modified-BV expression to determine kinetic performance as a function of pulse time. The determined exchange current density may be used with the modified-BV expression, with or without the sigmoid expressions, to analyze other characteristics of the electrochemical cell. Model parameters can be defined in terms of cell aging, making the overall kinetics model amenable to predictive estimates of cell kinetic performance along the aging timeline.

  1. Probabilistic performance-assessment modeling of the mixed waste landfill at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Peace, Gerald (Jerry) L. (.); Goering, Timothy James (GRAM, Inc.); Miller, Mark Laverne; Ho, Clifford Kuofei

    2007-01-01T23:59:59.000Z

    A probabilistic performance assessment has been conducted to evaluate the fate and transport of radionuclides (americium-241, cesium-137, cobalt-60, plutonium-238, plutonium-239, radium-226, radon-222, strontium-90, thorium-232, tritium, uranium-238), heavy metals (lead and cadmium), and volatile organic compounds (VOCs) at the Mixed Waste Landfill (MWL). Probabilistic analyses were performed to quantify uncertainties inherent in the system and models for a 1,000-year period, and sensitivity analyses were performed to identify parameters and processes that were most important to the simulated performance metrics. Comparisons between simulated results and measured values at the MWL were made to gain confidence in the models and perform calibrations when data were available. In addition, long-term monitoring requirements and triggers were recommended based on the results of the quantified uncertainty and sensitivity analyses.

  2. Numerical modeling of radiation-dominated and quantum-electrodynamically strong regimes of laser-plasma interaction

    SciTech Connect (OSTI)

    Sokolov, Igor V. [Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan 48109 (United States); Naumova, Natalia M. [Laboratoire d'Optique Appliquee, UMR 7639 ENSTA, Ecole Polytechnique, CNRS, 91761 Palaiseau (France); Nees, John A. [Center for Ultrafast Optical Science and FOCUS Center, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2011-09-15T23:59:59.000Z

    Ultra-strong laser pulses can be so intense that an electron in the focused beam loses significant energy due to {gamma}-photon emission while its motion deviates via the radiation back-reaction. Numerical methods and tools designed to simulate radiation-dominated and quantum-electrodynamically strong laser-plasma interactions are summarized here.

  3. A Fundamental Study of Convective Mixing of CO2 in Heterogeneous Geologic Media using Surrogate Fluids and Numerical Modeling

    E-Print Network [OSTI]

    of formation heterogeneity on convective mixing. Finite volume based numerical code was developed to capture of Canadian Petroleum Technology, 44(10). - Neufeld, J. A., Hesse M. A., Riaz, A., Hallworth M. A., Tchelepi, H. A., and Huppert H. E., 2010, Convective dissolution of carbon dioxide in saline aquifers, Geophys

  4. User's Manual for Data for Validating Models for PV Module Performance

    SciTech Connect (OSTI)

    Marion, W.; Anderberg, A.; Deline, C.; Glick, S.; Muller, M.; Perrin, G.; Rodriguez, J.; Rummel, S.; Terwilliger, K.; Silverman, T. J.

    2014-04-01T23:59:59.000Z

    This user's manual describes performance data measured for flat-plate photovoltaic (PV) modules installed in Cocoa, Florida, Eugene, Oregon, and Golden, Colorado. The data include PV module current-voltage curves and associated meteorological data for approximately one-year periods. These publicly available data are intended to facilitate the validation of existing models for predicting the performance of PV modules, and for the development of new and improved models. For comparing different modeling approaches, using these public data will provide transparency and more meaningful comparisons of the relative benefits.

  5. Performance Evaluation of a ground source heat pump system based on ANN and ANFIS models

    E-Print Network [OSTI]

    Sun, W.; Hu, P.; Lei, F.; Zhu, N.; Zhang,J.

    2014-01-01T23:59:59.000Z

    Performance evaluation of a ground source heat pump system based on ANN and ANFIS models Weijuan SUN a, Pingfang HUa,*, Fei Leia, Na Zhua, Jiangning Zhanga aHuazhong University of Science and Technology, Wuhan 430074, P. R. China Abstract...: The aim of this work is to calculate the heat pump coefficient of performance (COP) and the system COP of a ground source heat pump (GSHP) system based on an artificial neural network (ANN) model and (adaptive neuro-fuzzy inference system (ANFIS) model...

  6. DETERMINATION OF ELECTROCHEMICAL PERFORMANCE, AND THERMO-MECHANICALCHEMICAL STABILITY OF SOFCS FROM DEFECT MODELING

    SciTech Connect (OSTI)

    Wachsman, E.D.; Duncan, K.L.; Ebrahimi, F.

    2005-01-27T23:59:59.000Z

    The objectives of this project were to: provide fundamental relationships between SOFC performance and operating conditions and transient (time dependent) transport properties; extend models to thermo-mechanical stability, thermo-chemical stability, and multilayer structures; incorporate microstructural effects such as grain boundaries and grain-size distribution; experimentally verify models and devise strategies to obtain relevant material constants; and assemble software package for integration into SECA failure analysis models.

  7. Les business models dans la distribution : reprer les chemins de la performance 1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Les business models dans la distribution : repérer les chemins de la performance 1 Pierre Volle peuvent être adressées à pierre.volle@dauphine.fr 2 Les business models dans la distribution : repérer les business model (BM) reste largement à préciser. L'objectif de cet article est donc de mettre en évidence

  8. Methodology for Constructing Reduced-Order Power Block Performance Models for CSP Applications: Preprint

    SciTech Connect (OSTI)

    Wagner, M.

    2010-10-01T23:59:59.000Z

    The inherent variability of the solar resource presents a unique challenge for CSP systems. Incident solar irradiation can fluctuate widely over a short time scale, but plant performance must be assessed for long time periods. As a result, annual simulations with hourly (or sub-hourly) timesteps are the norm in CSP analysis. A highly detailed power cycle model provides accuracy but tends to suffer from prohibitively long run-times; alternatively, simplified empirical models can run quickly but don?t always provide enough information, accuracy, or flexibility for the modeler. The ideal model for feasibility-level analysis incorporates both the detail and accuracy of a first-principle model with the low computational load of a regression model. The work presented in this paper proposes a methodology for organizing and extracting information from the performance output of a detailed model, then using it to develop a flexible reduced-order regression model in a systematic and structured way. A similar but less generalized approach for characterizing power cycle performance and a reduced-order modeling methodology for CFD analysis of heat transfer from electronic devices have been presented. This paper builds on these publications and the non-dimensional approach originally described.

  9. Development of a Model Specification for Performance MonitoringSystems for Commercial Buildings

    SciTech Connect (OSTI)

    Haves, Philip; Hitchcock, Robert J.; Gillespie, Kenneth L.; Brook, Martha; Shockman, Christine; Deringer, Joseph J.; Kinney,Kristopher L.

    2006-08-01T23:59:59.000Z

    The paper describes the development of a model specification for performance monitoring systems for commercial buildings. The specification focuses on four key aspects of performance monitoring: (1) performance metrics; (2) measurement system requirements; (3) data acquisition and archiving; and (4) data visualization and reporting. The aim is to assist building owners in specifying the extensions to their control systems that are required to provide building operators with the information needed to operate their buildings more efficiently and to provide automated diagnostic tools with the information required to detect and diagnose faults and problems that degrade energy performance. The paper reviews the potential benefits of performance monitoring, describes the specification guide and discusses briefly the ways in which it could be implemented. A prototype advanced visualization tool is also described, along with its application to performance monitoring. The paper concludes with a description of the ways in which the specification and the visualization tool are being disseminated and deployed.

  10. Better Buildings Neighborhood Program Business Models Guide: Home Performance Contractor Business Model Conclusion

    Broader source: Energy.gov [DOE]

    The summary details important observations on home performance contractors and those observations impact on potential expansion into the residential energy efficiency market. Understanding these impacts can help home performance contractors, program administrators, and other actors create and/or sustain a business that promotes energy efficiency.

  11. Assessing the performance of thermospheric modelling with data assimilation throughout solar cycles 23 and 24

    E-Print Network [OSTI]

    Murray, Sophie A; Jackson, David R; Bruinsma, Sean L

    2015-01-01T23:59:59.000Z

    Data assimilation procedures have been developed for thermospheric models using satellite density measurements as part of the EU Framework Package 7 ATMOP Project. Two models were studied; one a general circulation model, TIEGCM, and the other a semi-empirical drag temperature model, DTM. Results of runs using data assimilation with these models were compared with independent density observations from CHAMP and GRACE satellites throughout solar cycles 23 and 24. Time periods of 60 days were examined at solar minimum and maximum, including the 2003 Hallowe'en storms. The differences between the physical and the semi-empirical models have been characterised. Results indicate that both models tend to show similar behaviour; underestimating densities at solar maximum, and overestimating them at solar minimum. DTM performed better at solar minimum, with both models less accurate at solar maximum. A mean improvement of ~4% was found using data assimilation with TIEGCM. With further improvements, the use of general ...

  12. Advanced modeling and simulation to design and manufacture high performance and reliable advanced microelectronics and microsystems.

    SciTech Connect (OSTI)

    Nettleship, Ian (University of Pittsburgh, Pittsburgh, PA); Hinklin, Thomas; Holcomb, David Joseph; Tandon, Rajan; Arguello, Jose Guadalupe, Jr. (,; .); Dempsey, James Franklin; Ewsuk, Kevin Gregory; Neilsen, Michael K.; Lanagan, Michael (Pennsylvania State University, University Park, PA)

    2007-07-01T23:59:59.000Z

    An interdisciplinary team of scientists and engineers having broad expertise in materials processing and properties, materials characterization, and computational mechanics was assembled to develop science-based modeling/simulation technology to design and reproducibly manufacture high performance and reliable, complex microelectronics and microsystems. The team's efforts focused on defining and developing a science-based infrastructure to enable predictive compaction, sintering, stress, and thermomechanical modeling in ''real systems'', including: (1) developing techniques to and determining materials properties and constitutive behavior required for modeling; (2) developing new, improved/updated models and modeling capabilities, (3) ensuring that models are representative of the physical phenomena being simulated; and (4) assessing existing modeling capabilities to identify advances necessary to facilitate the practical application of Sandia's predictive modeling technology.

  13. Peer review presentation on systems performance modeling and solar advisor support.

    SciTech Connect (OSTI)

    Cameron, Christopher P.

    2010-05-01T23:59:59.000Z

    Accurate Performance Models are Critical to Project Development and Technology Evaluation - Accuracy and Uncertainty of Commonly-Used Models Unknown and Models Disagree. A Model Evaluation Process Has Been Developed with Industry, and High-Quality Weather and System Performance Data Sets Have Been Collected: (1) Evaluation is Underway using Residual Analysis of Hourly and Sub-Hourly Data for Clear and Diffuse Climates to Evaluate and Improve Models; and (2) Initial Results Have Been or Will Soon Be Presented at Key Conferences. Evaluation of Widely-Used Module, Inverter, and Irradiance Models, Including Those in SAM, PVWatts, and PVSyst, Will Be Completed This Year. Stochastic Modeling Has Been Performed to Support Reliability Task and Will Add Value to Parametric Analysis. An Industry Workshop will be Held This Fall To Review Results, Set Priorities. Support and Analysis has been Provided for TPP's, SETP, and PV Community. Goals for Future Work Include: (1) Improving Understanding of and Validating System Derate Factors; and (2) Developing a Dynamic Electrical Model of Arrays with Shaded or Mismatched Modules to Support Transient Analysis of Large Fields.

  14. Resource Sharing in QPN-based Performance Models Charles University Prague, Faculty of Mathematics and Physics, Prague, Czech Republic.

    E-Print Network [OSTI]

    Resource Sharing in QPN-based Performance Models V. Babka Charles University Prague, Faculty needed to solve the model can be significantly influenced by resource sharing, capturing this influence separate resource and performance models and proposes a method of integrating these models at the tool

  15. Model for multi-strata safety performance measurements in the process industry

    E-Print Network [OSTI]

    Keren, Nir

    2004-09-30T23:59:59.000Z

    ) benchmarking of process safety elements among facilities; and (3) use of incident data collection from various sources for industrial safety performance assessment. The methods presently available for measurement of process safety within facilities... to explore the potential of integrating data sources and harnessing these databases for industrial safety performance assessment. In this study we developed models to pursue the measurement of samples of the strata described above. The measurement...

  16. MOSE: zooming on the Meso-NH mesoscale model performances at the surface layer at ESO sites (Paranal and Armazones)

    E-Print Network [OSTI]

    Lascaux, Franck; di Arcetri, INAF / Osservatorio Astrofisico; 10.1117/12.925934

    2012-01-01T23:59:59.000Z

    In the context of the MOSE project, in this contribution we present a detailed analysis of the Meso-NH mesoscale model performances and their dependency on the model and orography horizontal resolutions in proximity of the ground. The investigated sites are Cerro Paranal (site of the ESO Very Large Telescope - VLT) and Cerro Armazones (site of the ESO European Extremely Large Telescope - E-ELT), in Chile. At both sites, data from a rich statistical sample of different nights are available - from AWS (Automated Weather Stations) and masts - giving access to wind speed, wind direction and temperature at different levels near the ground (from 2 m to 30 m above the ground). In this study we discuss the use of a very high horizontal resolution (dX=0.1 km) numerical configuration that overcomes some specific limitations put in evidence with a standard configuration with dX=0.5 km. In both sites results are very promising. The study is co-funded by ESO and INAF.

  17. REVIEW OF MECHANISTIC UNDERSTANDING AND MODELING AND UNCERTAINTY ANALYSIS METHODS FOR PREDICTING CEMENTITIOUS BARRIER PERFORMANCE

    SciTech Connect (OSTI)

    Langton, C.; Kosson, D.

    2009-11-30T23:59:59.000Z

    Cementitious barriers for nuclear applications are one of the primary controls for preventing or limiting radionuclide release into the environment. At the present time, performance and risk assessments do not fully incorporate the effectiveness of engineered barriers because the processes that influence performance are coupled and complicated. Better understanding the behavior of cementitious barriers is necessary to evaluate and improve the design of materials and structures used for radioactive waste containment, life extension of current nuclear facilities, and design of future nuclear facilities, including those needed for nuclear fuel storage and processing, nuclear power production and waste management. The focus of the Cementitious Barriers Partnership (CBP) literature review is to document the current level of knowledge with respect to: (1) mechanisms and processes that directly influence the performance of cementitious materials (2) methodologies for modeling the performance of these mechanisms and processes and (3) approaches to addressing and quantifying uncertainties associated with performance predictions. This will serve as an important reference document for the professional community responsible for the design and performance assessment of cementitious materials in nuclear applications. This review also provides a multi-disciplinary foundation for identification, research, development and demonstration of improvements in conceptual understanding, measurements and performance modeling that would be lead to significant reductions in the uncertainties and improved confidence in the estimating the long-term performance of cementitious materials in nuclear applications. This report identifies: (1) technology gaps that may be filled by the CBP project and also (2) information and computational methods that are in currently being applied in related fields but have not yet been incorporated into performance assessments of cementitious barriers. The various chapters contain both a description of the mechanism or and a discussion of the current approaches to modeling the phenomena.

  18. Issues in Numerical Simulation of Fire Suppression

    SciTech Connect (OSTI)

    Tieszen, S.R.; Lopez, A.R.

    1999-04-12T23:59:59.000Z

    This paper outlines general physical and computational issues associated with performing numerical simulation of fire suppression. Fire suppression encompasses a broad range of chemistry and physics over a large range of time and length scales. The authors discuss the dominant physical/chemical processes important to fire suppression that must be captured by a fire suppression model to be of engineering usefulness. First-principles solutions are not possible due to computational limitations, even with the new generation of tera-flop computers. A basic strategy combining computational fluid dynamics (CFD) simulation techniques with sub-grid model approximations for processes that have length scales unresolvable by gridding is presented.

  19. A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California

    SciTech Connect (OSTI)

    D'Agnese, F.A.; O'Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma

    2002-11-22T23:59:59.000Z

    In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.

  20. Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC).

    SciTech Connect (OSTI)

    Schultz, Peter Andrew

    2011-12-01T23:59:59.000Z

    The objective of the U.S. Department of Energy Office of Nuclear Energy Advanced Modeling and Simulation Waste Integrated Performance and Safety Codes (NEAMS Waste IPSC) is to provide an integrated suite of computational modeling and simulation (M&S) capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive-waste storage facility or disposal repository. Achieving the objective of modeling the performance of a disposal scenario requires describing processes involved in waste form degradation and radionuclide release at the subcontinuum scale, beginning with mechanistic descriptions of chemical reactions and chemical kinetics at the atomic scale, and upscaling into effective, validated constitutive models for input to high-fidelity continuum scale codes for coupled multiphysics simulations of release and transport. Verification and validation (V&V) is required throughout the system to establish evidence-based metrics for the level of confidence in M&S codes and capabilities, including at the subcontiunuum scale and the constitutive models they inform or generate. This Report outlines the nature of the V&V challenge at the subcontinuum scale, an approach to incorporate V&V concepts into subcontinuum scale modeling and simulation (M&S), and a plan to incrementally incorporate effective V&V into subcontinuum scale M&S destined for use in the NEAMS Waste IPSC work flow to meet requirements of quantitative confidence in the constitutive models informed by subcontinuum scale phenomena.

  1. Model-based performance monitoring: Review of diagnostic methods and chiller case study

    SciTech Connect (OSTI)

    Haves, Phil; Khalsa, Sat Kartar

    2000-05-01T23:59:59.000Z

    The paper commences by reviewing the variety of technical approaches to the problem of detecting and diagnosing faulty operation in order to improve the actual performance of buildings. The review covers manual and automated methods, active testing and passive monitoring, the different classes of models used in fault detection, and methods of diagnosis. The process of model-based fault detection is then illustrated by describing the use of relatively simple empirical models of chiller energy performance to monitor equipment degradation and control problems. The CoolTools(trademark) chiller model identification package is used to fit the DOE-2 chiller model to on-site measurements from a building instrumented with high quality sensors. The need for simple algorithms to reject transient data, detect power surges and identify control problems is discussed, as is the use of energy balance checks to detect sensor problems. The accuracy with which the chiller model can be expected! to predict performance is assessed from the goodness of fit obtained and the implications for fault detection sensitivity and sensor accuracy requirements are discussed. A case study is described in which the model was applied retroactively to high-quality data collected in a San Francisco office building as part of a related project (Piette et al. 1999).

  2. Empirical Performance Model-Driven Data Layout Optimization and Library Call Selection for Tensor Contraction Expressions

    SciTech Connect (OSTI)

    Lu, Qingda; Gao, Xiaoyang; Krishnamoorthy, Sriram; Baumgartner, Gerald; Ramanujam, J.; Sadayappan, Ponnuswamy

    2012-03-01T23:59:59.000Z

    Empirical optimizers like ATLAS have been very effective in optimizing computational kernels in libraries. The best choice of parameters such as tile size and degree of loop unrolling is determined by executing different versions of the computation. In contrast, optimizing compilers use a model-driven approach to program transformation. While the model-driven approach of optimizing compilers is generally orders of magnitude faster than ATLAS-like library generators, its effectiveness can be limited by the accuracy of the performance models used. In this paper, we describe an approach where a class of computations is modeled in terms of constituent operations that are empirically measured, thereby allowing modeling of the overall execution time. The performance model with empirically determined cost components is used to perform data layout optimization together with the selection of library calls and layout transformations in the context of the Tensor Contraction Engine, a compiler for a high-level domain-specific language for expressing computational models in quantum chemistry. The effectiveness of the approach is demonstrated through experimental measurements on representative computations from quantum chemistry.

  3. FRAMEWORK AND APPLICATION FOR MODELING CONTROL ROOM CREW PERFORMANCE AT NUCLEAR POWER PLANTS

    SciTech Connect (OSTI)

    Ronald L Boring; David I Gertman; Tuan Q Tran; Brian F Gore

    2008-09-01T23:59:59.000Z

    This paper summarizes an emerging project regarding the utilization of high-fidelity MIDAS simulations for visualizing and modeling control room crew performance at nuclear power plants. The key envisioned uses for MIDAS-based control room simulations are: (i) the estimation of human error associated with advanced control room equipment and configurations, (ii) the investigative determination of contributory cognitive factors for risk significant scenarios involving control room operating crews, and (iii) the certification of reduced staffing levels in advanced control rooms. It is proposed that MIDAS serves as a key component for the effective modeling of cognition, elements of situation awareness, and risk associated with human performance in next generation control rooms.

  4. Development of long-term performance models for radioactive waste forms

    SciTech Connect (OSTI)

    Bacon, Diana H.; Pierce, Eric M.

    2011-03-22T23:59:59.000Z

    The long-term performance of solid radioactive waste is measured by the release rate of radionuclides into the environment, which depends on corrosion or weathering rates of the solid waste form. The reactions involved depend on the characteristics of the solid matrix containing the radioactive waste, the radionuclides of interest, and their interaction with surrounding geologic materials. This chapter describes thermo-hydro-mechanical and reactive transport models related to the long-term performance of solid radioactive waste forms, including metal, ceramic, glass, steam reformer and cement. Future trends involving Monte-Carlo simulations and coupled/multi-scale process modeling are also discussed.

  5. Modeling the Integrated Performance of Dispersion and Monolithic U-Mo Based Fuels

    SciTech Connect (OSTI)

    Daniel M. Wachs; Douglas E. Burkes; Steven L. Hayes; Karen Moore; Greg Miller; Gerard Hofman; Yeon Soo Kim

    2006-10-01T23:59:59.000Z

    The evaluation and prediction of integrated fuel performance is a critical component of the Reduced Enrichment for Research and Test Reactors (RERTR) program. The PLATE code is the primary tool being developed and used to perform these functions. The code is being modified to incorporate the most recent fuel/matrix interaction correlations as they become available for both aluminum and aluminum/silicon matrices. The code is also being adapted to treat cylindrical and square pin geometries to enhance the validation database by including the results gathered from various international partners. Additional modeling work has been initiated to evaluate the thermal and mechanical performance requirements unique to monolithic fuels during irradiation.

  6. ATS 680 A6: Applied Numerical Weather Prediction MW, 1:00-1:50 PM, ACRC Room 212B

    E-Print Network [OSTI]

    , Parameterization Schemes: Keys to Understanding Numerical Weather Prediction Models, Cambridge University Press in class. Numerical model The primary numerical model that will be u

  7. Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model

    E-Print Network [OSTI]

    Schuh, Harald

    with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

  8. Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

    SciTech Connect (OSTI)

    Leng, Shuai; Yu, Lifeng; Zhang, Yi; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Carter, Rickey [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Toledano, Alicia Y. [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)] [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.Methods: Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35 26 cm torso-shaped water phantom to simulate lesions with ?15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol = 5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128 128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.Results: In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC) between the average performance of the human observers and the model observer performance.Conclusions: In CT imaging of different sizes of low-contrast lesions (?15 HU), the performance of CHO with Gabor channels was highly correlated with human observer performance for the detection and localization tasks with uncertain lesion location in CT imaging at four clinically relevant dose levels. This suggests the ability of Gabor CHO model observers to meaningfully assess CT image quality for the purpose of optimizing scan protocols and radiation dose levels in detection and localization tasks for low-contrast lesions.

  9. NUMERICAL MODELING OF CO2 SEQUESTRATION WITH ANOZIE EBIGBO, ANDREAS BIELINSKI, ANDREAS KOPP, HOLGER CLASS, RAINER HELMIG

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    . It takes into account the two phases CO2 and brine and the components CO2 and water which can dissolve the conceptual model for a non-isothermal composi- tional CO2-water (brine) model based on the simulator MUFTE. MODEL For the description of the flow and transport processes of carbon dioxide and brine in a rock

  10. The Numerical Simulation of Turbulence

    E-Print Network [OSTI]

    W. Schmidt

    2007-12-06T23:59:59.000Z

    In this contribution, I give an overview of the various approaches toward the numerical modelling of turbulence, particularly, in the interstellar medium. The discussion is placed in a physical context, i. e. computational problems are motivated from basic physical considerations. Presenting selected examples for solutions to these problems, I introduce the basic ideas of the most commonly used numerical methods.

  11. NUMERICAL ANALYSIS KENDALL E. ATKINSON

    E-Print Network [OSTI]

    Atkinson, Kendall

    of mathematics and computer science that creates, analyzes, and implements algorithms for solving nu- merically mathematical models in science and engineering, and numerical analysis of increasing sophistication has been of numerical analysis varies from quite theoretical mathematical studies (e.g. see [5]) to computer science

  12. Waste package performance assessment: Deterministic system model, program scope and specification

    SciTech Connect (OSTI)

    O`Connell, W.J.; Drach, R.S.

    1986-10-02T23:59:59.000Z

    Integrated assessments of the performance of nuclear waste package designs must be made in order to qualify waste package designs with respect to containment time and release-rate requirements. PANDORA is a computer-based model of the waste package and of the processes affecting it over the long terms, specific to conditions at the proposed Yucca Mountain, Nevada, site. The processes PANDORA models include: changes in inventories due to radioactive decay, gamma radiation dose rate in and near the package, heat transfer, mechanical behavior, groundwater contact, corrosion, waste form alteration, and radionuclide release. The model tracks the development and coupling of these processes over time. The process models are simplified ones that focus on major effects and on coupling. This report documents our conceptual model development and provides a specification for the computer program. The current model is the first in a series. Succeeding models will use guidance from results of preceding models in the PANDORA series and will incorporate results of recently completed experiments and calculations on processes affecting performance. 22 refs., 21 figs., 9 tabs.

  13. Engineering Process Model for High-Temperature Electrolysis System Performance Evaluation

    SciTech Connect (OSTI)

    Carl M. Stoots; James E. O'Brien; Michael G. McKellar; Grant L. Hawkes

    2005-11-01T23:59:59.000Z

    In order to evaluate the potential hydrogen production performance of large-scale High-Temperature Electrolysis (HTE) operations, we have developed an engineering process model at INL using the commercial systems-analysis code HYSYS. Using this code, a detailed process flowsheet has been defined that includes all of the components that would be present in an actual plant such as pumps, compressors, heat exchangers, turbines, and the electrolyzer. Since the electrolyzer is not a standard HYSYS component, a custom one-dimensional electrolyzer model was developed for incorporation into the overall HYSYS process flowsheet. This electrolyzer model allows for the determination of the operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet gas flow rates, current density, cell active area, and external heat loss or gain. The one-dimensional electrolyzer model was validated by comparison with results obtained from a fully 3-D computational fluid dynamics model developed using FLUENT. This report provides details on the one-dimensional electrolyzer model, the HYSYS process model for a 300 MW HTE plant, and some representative results of parametric studies performed using the HYSYS process model.

  14. Propagating Uncertainty in Solar Panel Performance for Life Cycle Modeling in Early Stage Design

    E-Print Network [OSTI]

    Yang, Maria

    Propagating Uncertainty in Solar Panel Performance for Life Cycle Modeling in Early Stage Design. This work is conducted in the context of an amorphous photovoltaic (PV) panel, using data gathered from the National Solar Radiation Database, as well as realistic data collected from an experimental hardware setup

  15. VALIDATION OF PV PERFORMANCE MODELS USING SATELLITE-BASED IRRADIANCE MEASUREMENTS: A CASE STUDY

    E-Print Network [OSTI]

    Perez, Richard R.

    VALIDATION OF PV PERFORMANCE MODELS USING SATELLITE-BASED IRRADIANCE MEASUREMENTS: A CASE STUDY Clean Power Research Kirkland, WA e-mail: aparkins@cleanpower.com ABSTRACT Photovoltaic (PV) system and existing PV systems under a wide variety of environmental conditions. Ground based meteorological

  16. Performance Model for the Pool Size Behavior in Apache HTTP Server Software

    E-Print Network [OSTI]

    Do, Tien Van

    1 Performance Model for the Pool Size Behavior in Apache HTTP Server Software Tien Van Do, Ram Chakka, Thang Le Nhat, Udo Krieger Abstract The operation of the Web server's software architecture a way for a Web server software to organize (process or threading based) itself into more simultaneously

  17. Performance modeling and cell design for high concentration methanol fuel cells

    E-Print Network [OSTI]

    Chapter 50 Performance modeling and cell design for high concentration methanol fuel cells C. E The direct methanol fuel cell (DMFC) has become a lead- ing contender to replace the lithium-ion (Li density of liquid methanol (CH3OH) fuel is 4800 Wh l-1 , whereas the theoretical energy density of Li

  18. Experiments on a High Performance Hydraulic Manipulator Joint: Modelling for Control

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    Papadopoulos, Evangelos

    Experiments on a High Performance Hydraulic Manipulator Joint: Modelling for Control Glen Bilodeau]. A position-based impedance control law was applied to a hydraulic manipulator, [10]. Although the focus for further understanding the system and for developing a robust force controller. System parameters

  19. Modeling the Performance and the Energy Usage of Wireless Sensor Networks by Retrial Queueing Systems

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    Sztrik, János

    Modeling the Performance and the Energy Usage of Wireless Sensor Networks by Retrial Queueing and the energy usage of the sensor network. Two operations are compared. In the first case only the event driven requests can initiate reaching the radio trans- mission (RF) unit. Time driven requests have to wait

  20. A Model-Based Impedance Control Scheme for High-Performance Hydraulic Joints

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    Papadopoulos, Evangelos

    A Model-Based Impedance Control Scheme for High-Performance Hydraulic Joints Glen Bilodeau1, Greece Abstract Impedance control of a hydraulic servoactuator joint system is discussed in this paper individually. Due to nonlinear properties of hydraulic actuators, impedance control is difficult. The control