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Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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1

Simulation tools  

E-Print Network (OSTI)

In the last two decades, simulation tools made a significant contribution to the great progress in development of power electronics. Time to market was shortened and development costs were reduced drastically. Falling costs, as well as improved speed and precision, opened new fields of application. Today, continuous and switched circuits can be mixed. A comfortable number of powerful simulation tools is available. The users have to choose the best suitable for their application. Here a simple rule applies: The best available simulation tool is the tool the user is already used to (provided, it can solve the task). Abilities, speed, user friendliness and other features are continuously being improved—even though they are already powerful and comfortable. This paper aims at giving the reader an insight into the simulation of power electronics. Starting with a short description of the fundamentals of a simulation tool as well as properties of tools, several tools are presented. Starting with simplified models ...

Jenni, F

2006-01-01T23:59:59.000Z

2

Advanced beam-dynamics simulation tools for RIA.  

Science Conference Proceedings (OSTI)

We are developing multi-particle beam-dynamics simulation codes for RIA driver-linac simulations extending from the low-energy beam transport (LEBT) line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles. The codes have the physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for handling the effects of machine errors and other off-normal conditions. This year will mark the end of our project. In this paper we present the status of the work, describe some recent additions to the codes, and show some preliminary simulation results.

Garnett, R. W.; Wangler, T. P.; Billen, J. H.; Qiang, J.; Ryne, R.; Crandall, K. R.; Ostroumov, P.; York, R.; Zhao, Q.; Physics; LANL; LBNL; Tech Source; Michigan State Univ.

2005-01-01T23:59:59.000Z

3

Simulation Tools  

NLE Websites -- All DOE Office Websites (Extended Search)

Building simulation tool screen capture Building simulation tool screen capture Simulation Tools Researchers develop whole-building energy simulation software programs that allow architects and building engineers to design or retrofit buildings for maximum energy efficiency and occupant comfort. Programs developed by researchers include: the EnergyPlus whole building simulation program, the Modelica Buildings library for rapid prototyping and controls design, the Building Controls Virtual Test Bed for co-simulation and for model-based operation, and the GenOpt generic optimization program. Contacts Philip Haves PHaves@lbl.gov (510) 486-6512 Michael Wetter MWetter@lbl.gov (510) 486-6990 Links Simulation Research Group Batteries and Fuel Cells Buildings Energy Efficiency Applications Commercial Buildings

4

RIAPMTQ/Impact : beam-dynamics simulation tool for RIA.  

Science Conference Proceedings (OSTI)

We have developed a pair of multiparticle beam dynamics codes for end-to-end computer simulations of the proposed RIA heavy-ion driver linac. The two codes are: (1) an adaptation of PARMTEQ called RIAPMTQ for the normal-conducting-linac front end, and (2) IMPACT for the superconducting linac. The codes run on a PC as well as on parallel supercomputing platforms such as NERSC at LBNL. The parallel capability allows us to run simulations with large numbers of macroparticles for the computation of beam halo and beam-losses. The codes are being benchmarked for rms beam properties against previously existing codes at ANL and MSU. The work is being performed by a collaboration including LANL, LBNL, ANL, and Michigan State University (MSU). In this paper we present an overview, the status of the work, comparison of simulation results from RIAPMTQ and the ANL code TRACK for the ANL front-end design, and the first RIAPMTQ/IMPACT end-to-end multiprocessor simulation for the MSU design.

Wangler, T. P.; Billen, J. H.; Garnett, R. W.; Qiang, J.; Ryne, R.; Crandall, K. R.; Ostroumov, P.; Aseev, V. N.; Mustapha, B.; York, R. C.; Wu, X.; Zhao, Q.; Gorelov, D.; Doleans, M.; Physics; LANL; Tech Source; Michigan State Univ.

2006-01-01T23:59:59.000Z

5

NFCSim: A Dynamic Fuel Burnup and Fuel Cycle Simulation Tool  

Science Conference Proceedings (OSTI)

Technical Paper / Advances in Nuclear Fuel Management - Core Physics and Fuel Management Methods, Analytical Tools, and Benchmarks

Erich A. Schneider; Charles G. Bathke; Michael R. James

6

Advanced beam-dynamics simulation tools for the RIA driver linac,Part I: Low energy beam transport and radiofrequency quadrupole  

Science Conference Proceedings (OSTI)

Advanced Beam-Dynamics Simulation Tools for the RIA Driver Linac; Low Energy Beam Transport and Radiofrequency Quadrupole.

Wangler, Thomas P.; Crandall, Kenneth R.; Garnett, Robert W.; Gorelov, Dmitry; Ostroumov, Petr; Qiang, Ji; Ryne, Robert; York, Richard

2003-08-26T23:59:59.000Z

7

Developing an integrated building design tool by coupling building energy simulation and computational fluid dynamics programs  

E-Print Network (OSTI)

Building energy simulation (ES) and computational fluid dynamics (CFD) can play important roles in building design by providing essential information to help design energy-efficient, thermally comfortable and healthy ...

Zhai, Zhiqiang, 1971-

2003-01-01T23:59:59.000Z

8

Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool: Preprint  

DOE Green Energy (OSTI)

In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states.

Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

2012-11-01T23:59:59.000Z

9

Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool: Preprint  

SciTech Connect

In 2007, the FAST wind turbine simulation tool, developed and maintained by the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL), was expanded to include capabilities that are suitable for modeling floating offshore wind turbines. In an effort to validate FAST and other offshore wind energy modeling tools, DOE funded the DeepCwind project that tested three prototype floating wind turbines at 1/50th scale in a wave basin, including a semisubmersible, a tension-leg platform, and a spar buoy. This paper describes the use of the results of the spar wave basin tests to calibrate and validate the FAST offshore floating simulation tool, and presents some initial results of simulated dynamic responses of the spar to several combinations of wind and sea states.

Browning, J. R.; Jonkman, J.; Robertson, A.; Goupee, A. J.

2012-11-01T23:59:59.000Z

10

Design and Analysis of a Tool for Planning and Simulating Dynamic Vertical Transport  

Science Conference Proceedings (OSTI)

Nowadays, most of the main companies in the vertical transport industry are researching tools capable of providing support for the design process of elevator systems. Numerous decisions have to be taken to obtain an accurate, comfortable, and high-quality ... Keywords: Vertical transport, elevator, lift, simulation

Pablo Cortés; Jesús Muñuzuri; Luis Onieva

2006-04-01T23:59:59.000Z

11

Policy Strategies and Paths to promote Sustainable Energy Systems- The dynamic Invert Simulation Tool  

SciTech Connect

The European Union has established a number of targetsregarding energy efficiency, Renewable Energy Sources (RES) and CO2reductions as the 'GREEN PAPER on Energy Efficiency', the Directive for'promotion of the use of bio-fuels or other renewable fuels fortransport' or 'Directive of the European Parliament of the Council on thepromotion of cogeneration based on a useful heat demand in the internalenergy market'. A lot of the according RES and RUE measures are notattractive for investors from an economic point of view. Thereforegovernmentsall over the world have to spend public money to promotethese technologies/measures to bring them into market. These expenditureshave to be adjusted to budget concerns and should be spent mostefficiently. Therefore, the spent money has to be dedicated totechnologies and efficiency measures with the best yield in CO2 reductionwithout wasting money. The core question: "How can public money - forpromoting sustainable energy systems - be spent most efficiently toreduce GHG-emissions?" has been well investigated by the European projectInvert. In course of this project a simulation tool has been designed toanswer this core question. This paper describes the modelling with theInvert simulation tool and shows the key features necessary forsimulating the energy system. A definition of 'Promotion SchemeEfficiency' is given which allows estimating the most cost effectivetechnologies and/or efficiency measures to reduce CO2 emissions.Investigations performed with the Invert simulation tool deliver anoptimum portfolio mix of technologies and efficiency measures for eachselected region. Within Invert seven European regions were simulated andfor the Austrian case study the detailed portfolio mix is shown andpolitical conclusions are derived.

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-05-01T23:59:59.000Z

12

Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool: Preprint  

NLE Websites -- All DOE Office Websites (Extended Search)

Calibration and Validation of a Calibration and Validation of a Spar-Type Floating Offshore Wind Turbine Model using the FAST Dynamic Simulation Tool Preprint J.R. Browning University of Colorado-Boulder J. Jonkman and A. Robertson National Renewable Energy Laboratory A.J. Goupee University of Maine Presented at the Science of Making Torque from Wind Oldenburg, Germany October 9-11, 2012 Conference Paper NREL/CP-5000-56138 November 2012 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes.

13

A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation  

E-Print Network (OSTI)

The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster, outcomes of blowouts are unknown and should be studied before starting an operation. Plans should be available to prevent blowouts or provide safe and secure ways of controlling the well before the drilling operation starts. The plan should include procedures in case of any blowout incident as a proactive measure. A few commercial softwares are available in the industry for dynamic kill and transient modeling. All models are proprietary and very complex which reduces the flexibility of the program for specific cases. The purpose of this study is to develop a pseudo transient hydraulic simulator for dynamic kill operations. The idea and concept is to consider the flow of each phase as a single phase flow. The summation of hydrostatic and frictional pressure of each phase determines the bottomhole pressure during the dynamic kill operation. The simulator should be versatile and capable of handling special cases that may encounter during blowouts. Some of the main features of the proposed dynamic kill simulator include; quick and robust simulation, fluid properties are corrected for pressure and temperature, sensitivity analysis can be performed through slide bars, and capable of handling variety of wellbore trajectories. The results from the proposed simulator were compared to the result of commercial software, OLGA ABC. The results were in agreement with each other. It is recommended to apply the simulator for operations with required kill fluid volumes of one to two wellbore volumes.

Haghshenas, Arash

2013-05-01T23:59:59.000Z

14

Ion trap simulation tools.  

Science Conference Proceedings (OSTI)

Ion traps present a potential architecture for future quantum computers. These computers are of interest due to their increased power over classical computers stemming from the superposition of states and the resulting capability to simultaneously perform many computations. This paper describes a software application used to prepare and visualize simulations of trapping and maneuvering ions in ion traps.

Hamlet, Benjamin Roger

2009-02-01T23:59:59.000Z

15

NEAMS ToolKit: advanced computational tools for modeling & simulation...  

NLE Websites -- All DOE Office Websites (Extended Search)

NEAMS ToolKit: advanced computational tools for modeling & simulation of advanced reactor systems Director's Welcome Organization Achievements Highlights Fact Sheets, Brochures &...

16

Autonomie Automotive Simulation Tool | Open Energy Information  

Open Energy Info (EERE)

Autonomie Automotive Simulation Tool Autonomie Automotive Simulation Tool Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Autonomie Automotive Simulation Tool Agency/Company /Organization: Argonne National Laboratory Focus Area: Economic Development, Vehicles Phase: Create a Vision Topics: Pathways analysis Resource Type: Software/modeling tools User Interface: Desktop Application Website: www.transportation.anl.gov/modeling_simulation/PSAT/autonomie.html OpenEI Keyword(s): Energy Efficiency and Renewable Energy (EERE) Tools Language: English References: Autonomie[1] Rapidly evaluate new powertrain and propulsion technologies for improving fuel economy through virtual design and analysis in a math-based simulation environment. Argonne has developed a new tool, called Autonomie, to accelerate the

17

Next generation computational tools for extreme-scale simulation of dynamic fracture and fragmentation in three dimensions  

E-Print Network (OSTI)

The accurate modeling of dynamic fracture and fragmentation remains one of the most difficult challenges in computational mechanics research. As part of this thesis, a scalable algorithm for modeling dynamic fracture and ...

Seagraves, Andrew Nathan

2013-01-01T23:59:59.000Z

18

Optimization of naïve dynamic binary instrumentation Tools/  

E-Print Network (OSTI)

The proliferation of dynamic program analysis tools has done much to ease the burden of developing complex software. However, creating such tools remains a challenge. Dynamic binary instrumentation frameworks such as ...

Kleckner, Reid (Reid N.)

2011-01-01T23:59:59.000Z

19

ulvacsim.paper.doc 08/20/99 p. 1 of 23 Dynamic Simulation of a Multichamber CVD Cluster Tool  

E-Print Network (OSTI)

and WF6 utilization, analysis of experimental data for recipe improvement, and development and debugging of equipment controller software and operation. a) Current address: Intel Corporation, Hillsboro, OR #12 the behavior of a full-scale manufacturing tool with multiple chambers (two reactors, a load lock and a central

Rubloff, Gary W.

20

Radiation in molecular dynamic simulations  

DOE Green Energy (OSTI)

Hot dense radiative (HDR) plasmas common to Inertial Confinement Fusion (ICF) and stellar interiors have high temperature (a few hundred eV to tens of keV), high density (tens to hundreds of g/cc) and high pressure (hundreds of Megabars to thousands of Gigabars). Typically, such plasmas undergo collisional, radiative, atomic and possibly thermonuclear processes. In order to describe HDR plasmas, computational physicists in ICF and astrophysics use atomic-scale microphysical models implemented in various simulation codes. Experimental validation of the models used to describe HDR plasmas are difficult to perform. Direct Numerical Simulation (DNS) of the many-body interactions of plasmas is a promising approach to model validation but, previous work either relies on the collisionless approximation or ignores radiation. We present a new numerical simulation technique to address a currently unsolved problem: the extension of molecular dynamics to collisional plasmas including emission and absorption of radiation. The new technique passes a key test: it relaxes to a blackbody spectrum for a plasma in local thermodynamic equilibrium. This new tool also provides a method for assessing the accuracy of energy and momentum exchange models in hot dense plasmas. As an example, we simulate the evolution of non-equilibrium electron, ion, and radiation temperatures for a hydrogen plasma using the new molecular dynamics simulation capability.

Glosli, J; Graziani, F; More, R; Murillo, M; Streitz, F; Surh, M

2008-10-13T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

A Data Center Energy Efficiency Simulation Tool  

NLE Websites -- All DOE Office Websites (Extended Search)

A Data Center Energy Efficiency Simulation Tool Speaker(s): Zahl Limbuwala Date: July 16, 2009 - 12:00pm Location: 90-3122 This talk will be an introduction to the BCS Data Centre...

22

A software tool to compare measured and simulated building energy...  

NLE Websites -- All DOE Office Websites (Extended Search)

Contacts Media Contacts A software tool to compare measured and simulated building energy performance data Title A software tool to compare measured and simulated building...

23

Incorporating LCA tools in integrated simulation environments  

SciTech Connect

In this paper we address the issue of building data schema evolution in integrated simulation environments, as seen from the perspective of incorporating LCA tools within these environments. First we describe the key features of an integrated simulation environment designed for expandability, focusing on (a) the mechanism for the expansion of the integrated environment, and (b) its overall system architecture that allows processes and data to be added to the system without modifications or restructuring of existing code. We then focus on how the data schema allows the inclusion and maintenance of specialized construction objects bearing LCA data. Finally, we discuss various integration issues that arise from modeling capabilities and idiosyncrasies of individual simulation and analysis tools.

Pal, Vineeta; Papamichael, Konstantinos; Bourassa, Norman; Loffeld, John J.

2001-02-01T23:59:59.000Z

24

AVESTAR® - Gasification Dynamic Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Meet Our Partners Simulators IGCC Gasification Combined Cycle NGCC SCOT Oxy-coal Shale Gas 3D Virtual IGCC Training How to Register for Training IGCC Gasification Combined...

25

Dynamic Infrared Simulation.  

E-Print Network (OSTI)

?? The increased usage of infrared sensors by pilots has created a growing demand for simulated environments based on infrared radiation. This has led to… (more)

Dehlin, Jonas

2006-01-01T23:59:59.000Z

26

Fluctuations in molecular dynamics simulations  

Science Conference Proceedings (OSTI)

Statistical fluctuations of a system about its equilibrium state, monitored in a molecular dynamics simulation, are an effective means of computing the thermodynamic and kinetic properties of interfaces in metals and alloys. In this work, three applications ... Keywords: Fluctuations, Grain boundaries, Interfaces, Interfacial free energy, Mobility, Molecular dynamics

J. J. Hoyt; Z. T. Trautt; M. Upmanyu

2010-03-01T23:59:59.000Z

27

A Molecular Dynamics Simulation  

Science Conference Proceedings (OSTI)

Ab Initio Local Energy and Local Stress Calculations: Applications to Materials ... Computational Fluid Dynamics and Experimental Results for the Horizontal .... Films and Applications to a New Generation of Multifunctional Devices/Systems.

28

Design tools for complex dynamic security systems.  

SciTech Connect

The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle.

Byrne, Raymond Harry; Rigdon, James Brian; Rohrer, Brandon Robinson; Laguna, Glenn A.; Robinett, Rush D. III (.; ); Groom, Kenneth Neal; Wilson, David Gerald; Bickerstaff, Robert J.; Harrington, John J.

2007-01-01T23:59:59.000Z

29

Molecular dynamics simulation of displacement cascades in FeCr alloys  

E-Print Network (OSTI)

Molecular dynamics simulation of displacement cascades in Fe­Cr alloys L. Malerba a,*, D. Terentyev by displacement cascades in the relevant material. Molecular dynamics (MD) is well known to be the simulation tool

30

System dynamics simulation of the telecom industry  

E-Print Network (OSTI)

The primary goal of this research effort was to integrate several pieces of relatively simple dynamics simulations into a full blown system dynamics simulation of the telecom industry. The economic simulation model was ...

Shapira, Gil, 1971-

2004-01-01T23:59:59.000Z

31

A Smart Home Simulation Tool The Development of a Simulation Tool for Measuring  

E-Print Network (OSTI)

that are suitable for private homes. These wind turbines typically have wattage of less than 10 KW. The smaller ones resources such as wind turbines and solar panels. The key focus areas of the developed simulation tool In the power network the producers are responsible for producing the power in power plants and wind turbines

32

DESASS: A software tool for designing, simulating and optimising WWTPs  

Science Conference Proceedings (OSTI)

This paper presents a very useful software tool to design, simulate and optimise wastewater treatment plants. The program is called DESASS (DEsign and Simulation of Activated Sludge Systems) and has been developed by CALAGUA research group. The mathematical ... Keywords: BNRM1, Modelling, Optimisation, Simulation, Software tool, WWTPs design, Wastewater, pH calculation

J. Ferrer; A. Seco; J. Serralta; J. Ribes; J. Manga; E. Asensi; J. J. Morenilla; F. Llavador

2008-01-01T23:59:59.000Z

33

Modeling Framework and Associated Simulation Tools for the ...  

Science Conference Proceedings (OSTI)

A modeling framework and the associated simulation tools are presented. It allows the ... Thermochemical Degradation Mechanisms of SiC/BN/SiC Composites.

34

Tools and Equipment Modeling for Automobile Interactive Assembling Operating Simulation  

SciTech Connect

Tools and equipment play an important role in the simulation of virtual assembly, especially in the assembly process simulation and plan. Because of variety in function and complexity in structure and manipulation, the simulation of tools and equipments remains to be a challenge for interactive assembly operation. Based on analysis of details and characteristics of interactive operations for automobile assembly, the functional requirement for tools and equipments of automobile assembly is given. Then, a unified modeling method for information expression and function realization of general tools and equipments is represented, and the handling methods of manual, semi-automatic, automatic tools and equipments are discussed. Finally, the application in assembly simulation of rear suspension and front suspension of Roewe 750 automobile is given. The result shows that the modeling and handling methods are applicable in the interactive simulation of various tools and equipments, and can also be used for supporting assembly process planning in virtual environment.

Wu Dianliang; Zhu Hongmin [Shanghai Jiao Tong University (China); Shanghai Key Laboratory of Advance Manufacturing Environment (China)

2010-05-21T23:59:59.000Z

35

Demonstration of a Computational Fluid Dynamics (CFD) Tool Used...  

NLE Websites -- All DOE Office Websites (Extended Search)

Demonstration of a Computational Fluid Dynamics (CFD) Tool Used for Data Center Modeling, Thermal Analysis and Operational Management Speaker(s): Saket Karajgikar Date: November...

36

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Renewable...  

NLE Websites -- All DOE Office Websites (Extended Search)

NREL Energy Analysis Science and Technology Technology Transfer Technology Deployment Energy Systems Integration Dynamic Maps, GIS Data, and Analysis Tools Search More Search...

37

Simulation of Tailrace Hydrodynamics Using Computational Fluid Dynamics Models  

DOE Green Energy (OSTI)

This report investigates the feasibility of using computational fluid dynamics (CFD) tools to investigate hydrodynamic flow fields surrounding the tailrace zone below large hydraulic structures. Previous and ongoing studies using CFD tools to simulate gradually varied flow with multiple constituents and forebay/intake hydrodynamics have shown that CFD tools can provide valuable information for hydraulic and biological evaluation of fish passage near hydraulic structures. These studies however are incapable of simulating the rapidly varying flow fields that involving breakup of the free-surface, such as those through and below high flow outfalls and spillways. Although the use of CFD tools for these types of flow are still an active area of research, initial applications discussed in this report show that these tools are capable of simulating the primary features of these highly transient flow fields.

Cook, Chris B; Richmond, Marshall C

2001-05-01T23:59:59.000Z

38

Large-Scale Hybrid Dynamic Simulation Employing Field Measurements  

Science Conference Proceedings (OSTI)

Simulation and measurements are two primary ways for power engineers to gain understanding of system behaviors and thus accomplish tasks in system planning and operation. Many well-developed simulation tools are available in today's market. On the other hand, large amount of measured data can be obtained from traditional SCADA systems and currently fast growing phasor networks. However, simulation and measurement are still two separate worlds. There is a need to combine the advantages of simulation and measurements. In view of this, this paper proposes the concept of hybrid dynamic simulation which opens up traditional simulation by providing entries for measurements. A method is presented to implement hybrid simulation with PSLF/PSDS. Test studies show the validity of the proposed hybrid simulation method. Applications of such hybrid simulation include system event playback, model validation, and software validation.

Huang, Zhenyu; Guttromson, Ross T.; Hauer, John F.

2004-06-30T23:59:59.000Z

39

Simulation tool for P25 ISSI protocols  

Science Conference Proceedings (OSTI)

... be used to simulate networks containing many RFSSs and several hundred Subscriber Units (SUs) generating both talk group calls and unit to unit ...

2011-10-17T23:59:59.000Z

40

Modeling and Simulation Tools for Emergency Management ...  

Science Conference Proceedings (OSTI)

... ANL-Models Span the Deployment Spectrum and can be Used in ... modeling and simulation results in a ... constructing and running agent-based ...

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Building Energy Software Tools Directory: Frame Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Frame Simulator Frame Simulator Frame Simulator logo Frame Simulator makes calculation of the thermal transmittance in windows and building components an extremely easy process. It can be used to: analyze how heat flows through building components and fenestrations estimate surface temperatures and predict condensation problems discover weak points in window frames calculate thermal transmittance Uf and linear conductance Lf2d of any type of window frame as well as the Uw thermal transmittance of entire complex fenestration. Precise simulation of the heat transfer is performed using a two-dimensional numerical method for steady state boundary conditions conforming to ISO 10077-2 (finite elements). Screen Shots Keywords 2D, heat transfer, thermal analysis, thermal transmittance, thermal

42

The application of discrete event simulation and system dynamics in the logistics and supply chain context  

Science Conference Proceedings (OSTI)

Discrete event simulation (DES) and system dynamics (SD) are two modelling approaches widely used as decision support tools in logistics and supply chain management (LSCM). A widely held belief exists that SD is mostly used to model problems at a strategic ... Keywords: Comparison of methods, Discrete-event simulation, Logistics and supply chain management, Simulation modelling, System dynamics

Antuela A. Tako; Stewart Robinson

2012-03-01T23:59:59.000Z

43

New Automotive Air Conditioning System Simulation Tool Developed in MATLAB/Simulink  

DOE Green Energy (OSTI)

Further improvements in vehicle fuel efficiency require accurate evaluation of the vehicle's transient total power requirement. When operated, the air conditioning (A/C) system is the largest auxiliary load on a vehicle; therefore, accurate evaluation of the load it places on the vehicle's engine and/or energy storage system is especially important. Vehicle simulation software, such as 'Autonomie,' has been used by OEMs to evaluate vehicles' energy performance. A transient A/C simulation tool incorporated into vehicle simulation models would also provide a tool for developing more efficient A/C systems through a thorough consideration of the transient A/C system performance. The dynamic system simulation software Matlab/Simulink was used to develop new and more efficient vehicle energy system controls. The various modeling methods used for the new simulation tool are described in detail. Comparison with measured data is provided to demonstrate the validity of the model.

Kiss, T.; Chaney, L.; Meyer, J.

2013-07-01T23:59:59.000Z

44

PLATO: a new piecewise linear simulation tool  

Science Conference Proceedings (OSTI)

This paper describes the basic concepts of a new piecewise linear circuit simulation program called PLATO. Piecewise linear modeling is a very generic and powerful approach to the modeling of electronic components. It allows for the use of macro modeling ...

M. T. van Stiphout; J. T. J. van Eijndhoven; H. W. Buurman

1990-03-01T23:59:59.000Z

45

11/11/2002 1AVS 49th Int'l Symp. MS-MoA7 (Oct. 29, 2002) -Cho Dynamic Simulation and Optimization  

E-Print Network (OSTI)

'l Symp. MS-MoA7 (Oct. 29, 2002) - Cho Scope & Strategy Multilevel modeling & simulation incorporating dynamics &Multilevel modeling & simulation incorporating dynamics & stochasticsstochastics ESH fluctuations Incorporate capability in models for dynamics & stochastics Process & tool Fundamental science Si

Rubloff, Gary W.

46

A scenario generation tool for DDF simulation testbeds  

Science Conference Proceedings (OSTI)

An interactive tool has been developed for visualizing and creating scaled battlefield based scenarios for use in a simulation testbed to develop and test distributed data fusion and ad-hoc networking algorithms. This paper discuses the design requirements ...

G. Srimathveeravalli; N. Subramanian; T. Kesavadas

2004-12-01T23:59:59.000Z

47

Dynamic Heart?Body Simulator  

Science Conference Proceedings (OSTI)

A high?speed electronic analog computer is described which is a useful research tool in the analysis of body?surface voltages produced by a fixed?position

Ernest Frank

1954-01-01T23:59:59.000Z

48

Phonostat: Thermostatting phonons in molecular dynamics simulations  

E-Print Network (OSTI)

Thermostat algorithms in a molecular dynamics simulation maintain an average temperature of a system by regulating the atomic velocities rather than the internal degrees of freedom. Herein, we present a “phonostat” algorithm ...

Raghunathan, Rajamani

49

LAMMPS Molecular Dynamics Simulator - TMS  

Science Conference Proceedings (OSTI)

Nov 8, 2007 ... LAMMPS stands for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has potentials for soft materials (biomolecules, ...

50

Molecular Dynamics Simulation of Macromolecules Using Graphics Processing Unit  

E-Print Network (OSTI)

Molecular dynamics (MD) simulation is a powerful computational tool to study the behavior of macromolecular systems. But many simulations of this field are limited in spatial or temporal scale by the available computational resource. In recent years, graphics processing unit (GPU) provides unprecedented computational power for scientific applications. Many MD algorithms suit with the multithread nature of GPU. In this paper, MD algorithms for macromolecular systems that run entirely on GPU are presented. Compared to the MD simulation with free software GROMACS on a single CPU core, our codes achieve about 10 times speed-up on a single GPU. For validation, we have performed MD simulations of polymer crystallization on GPU, and the results observed perfectly agree with computations on CPU. Therefore, our single GPU codes have already provided an inexpensive alternative for macromolecular simulations on traditional CPU clusters and they can also be used as a basis to develop parallel GPU programs to further speedup the computations.

Ji Xu; Ying Ren; Wei Ge; Xiang Yu; Xiaozhen Yang; Jinghai Li

2010-01-21T23:59:59.000Z

51

Dynamics Simulation in a Wave Environment  

NLE Websites -- All DOE Office Websites (Extended Search)

Coupled Dynamic Simulation in a Wave Coupled Dynamic Simulation in a Wave Environment (Navatek, AEGIR, and WECs) Marine and Hydrokinetics Instrumentation Workshop 9 July 2012 David Kring, Navatek Ltd. Presentation Overview * Introduction to Navatek * AEGIR brief: resistance, seakeeping, global and local loads a 3D, NURBS-based, high-order, Rankine boundary element method ... from same lab as at MIT as WAMIT and SWAN, with pFFT acceleration coupling with controls, structures, aerodynamics, power take-offs * Some WEC applications at Navatek 2 Honolulu, Hawaii, USA Company Background A "Research Shipyard" based in Honolulu, HI Combining simulation-based design with prototype construction

52

An ecologically inspired simulation tool for managing digital ecosystems  

Science Conference Proceedings (OSTI)

In this paper we present an ecologically inspired multi-agent based simulation tool for finding and analysing networks of collaborations in a digital ecosystem. Digital ecosystems are defined as open, self-organising environments inside which digital ... Keywords: collaboration, complex networks, digital ecosystems, ecology, multi-agent systems, mutualism

Miguel Lurgi

2010-10-01T23:59:59.000Z

53

Structural dynamics test simulation and optimization for aerospace components  

SciTech Connect

This paper initially describes an innovative approach to product realization called Knowledge Based Testing (KBT). This research program integrates test simulation and optimization software, rapid fabrication techniques and computational model validation to support a new experimentally-based design concept. This design concept implements well defined tests earlier in the design cycle enabling the realization of highly reliable aerospace components. A test simulation and optimization software environment provides engineers with an essential tool needed to support this KBT approach. This software environment, called the Virtual Environment for Test Optimization (VETO), integrates analysis and test based models to support optimal structural dynamic test design. A goal in developing this software tool is to provide test and analysis engineers with a capability of mathematically simulating the complete structural dynamics test environment within a computer. A developed computational model of an aerospace component can be combined with analytical and/or experimentally derived models of typical structural dynamic test instrumentation within the VETO to determine an optimal test design. The VETO provides the user with a unique analysis and visualization environment to evaluate new and existing test methods in addition to simulating specific experiments designed to maximize test based information needed to validate computational models. The results of both a modal and a vibration test design are presented for a reentry vehicle and a space truss structure.

Klenke, S.E.; Baca, T.J.

1996-06-01T23:59:59.000Z

54

Monte Carlo Simulations of Neutron Oil well Logging Tools  

E-Print Network (OSTI)

Monte Carlo simulations of simple neutron oil well logging tools into typical geological formations are presented.The simulated tools consist of both 14 MeV pulsed and continuous Am-Be neutron sources with time gated and continuous gamma ray detectors respectively.The geological formation consists of pure limestone with 15% absolute porosity in a wide range of oil saturation.The particle transport was performed with the Monte Carlo N-Particle Transport Code System, MCNP-4B.Several gamma ray spectra were obtained at the detector position that allow to perform composition analysis of the formation.In particular, the ratio C/O was analyzed as an indicator of oil saturation.Further calculations are proposed to simulate actual detector responses in order to contribute to understand the relation between the detector response with the formation composition

Azcurra, M

2002-01-01T23:59:59.000Z

55

A simulation tool for the study of symmetric inversions in bacterial genomes  

Science Conference Proceedings (OSTI)

We present the tool SIB that simulates genomic inversions in bacterial chromosomes. The tool simulates symmetric inversions but allows the appearance of nonsymmetric inversions by simulating small syntenic blocks frequently observed on bacterial genome ...

Ulisses Dias; Zanoni Dias; João C. Setubal

2010-10-01T23:59:59.000Z

56

Computing 1-D atomic densities in macromolecular simulations: the Density Profile Tool for VMD  

E-Print Network (OSTI)

Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment with the ability to interactively compute and visualize 1-D projections of various density functions of molecular models. We describe how the plugin is used to perform computations both via a graphical interface and programmatically. Results are presented for realistic examples, all-atom bilayer models, showing how mass and electron densities readily provide measurements such as membrane thickness, location of structural elements, and how they compare to X-ray diffraction experiments.

Giorgino, Toni

2013-01-01T23:59:59.000Z

57

RTSTEP regional transportation simulation tool for emergency planning - final report.  

Science Conference Proceedings (OSTI)

Large-scale evacuations from major cities during no-notice events - such as chemical or radiological attacks, hazardous material spills, or earthquakes - have an obvious impact on large regions rather than on just the directly affected area. The scope of impact includes the accommodation of emergency evacuation traffic throughout a very large area; the planning of resources to respond appropriately to the needs of the affected population; the placement of medical supplies and decontamination equipment; and the assessment and determination of primary escape routes, as well as routes for incoming emergency responders. Compared to events with advance notice, such as evacuations based on hurricanes approaching an affected area, the response to no-notice events relies exclusively on pre-planning and general regional emergency preparedness. Another unique issue is the lack of a full and immediate understanding of the underlying threats to the population, making it even more essential to gain extensive knowledge of the available resources, the chain of command, and established procedures. Given the size of the area affected, an advanced understanding of the regional transportation systems is essential to help with the planning for such events. The objectives of the work described here (carried out by Argonne National Laboratory) is the development of a multi-modal regional transportation model that allows for the analysis of different evacuation scenarios and emergency response strategies to build a wealth of knowledge that can be used to develop appropriate regional emergency response plans. The focus of this work is on the effects of no-notice evacuations on the regional transportation network, as well as the response of the transportation network to the sudden and unusual demand. The effects are dynamic in nature, with scenarios changing potentially from minute to minute. The response to a radiological or chemical hazard will be based on the time-delayed dispersion of such materials over a large area, with responders trying to mitigate the immediate danger to the population in a variety of ways that may change over time (e.g., in-place evacuation, staged evacuations, and declarations of growing evacuation zones over time). In addition, available resources will be marshaled in unusual ways, such as the repurposing of transit vehicles to support mass evacuations. Thus, any simulation strategy will need to be able to address highly dynamic effects and will need to be able to handle any mode of ground transportation. Depending on the urgency and timeline of the event, emergency responders may also direct evacuees to leave largely on foot, keeping roadways as clear as possible for emergency responders, logistics, mass transport, and law enforcement. This RTSTEP project developed a regional emergency evacuation modeling tool for the Chicago Metropolitan Area that emergency responders can use to pre-plan evacuation strategies and compare different response strategies on the basis of a rather realistic model of the underlying complex transportation system. This approach is a significant improvement over existing response strategies that are largely based on experience gained from small-scale events, anecdotal evidence, and extrapolation to the scale of the assumed emergency. The new tool will thus add to the toolbox available to emergency response planners to help them design appropriate generalized procedures and strategies that lead to an improved outcome when used during an actual event.

Ley, H.; Sokolov, V.; Hope, M.; Auld, J.; Zhang, K.; Park, Y.; Kang, X. (Energy Systems)

2012-01-20T23:59:59.000Z

58

Dynamic simulation recalls condensate piping event  

Science Conference Proceedings (OSTI)

This article describes how experience gained from simulating and reconstructing a condensate piping event will be used by Consolidated Edison to analyze control system problems. A cooperative effort by Con Edison and the Chemical Engineering Department at Polytechnic University used modular modeling system to investigate the probable cause of a Con Edison condensate piping event. Con Edison commissioned the work to serve as a case study for the more general problem of control systems analysis using dynamic simulation and MMS.

Farrell, R.J.; Reneberg, K.O. (Polytechnic Univ., Brooklyn, NY (United States)); Moy, H.C. (Consolidated Edison Co., New York, NY (United States))

1994-05-01T23:59:59.000Z

59

A versatile simulation tool for the design and verification of military vehicle power systems  

E-Print Network (OSTI)

The design of the electric platform in military vehicles requires the ability to determine the best combination of power system components that support the desired operational abilities, while minimizing the size, weight, cost, and impact of the overall power system. Because prototypes are both time consuming, rigid, and costly, they have become inadequate for verifying system performance. By using simulations, engineers can best plan for and observe the associations between missions (including modes of operation and system scenarios) and system performance in a dynamic, realistic environment. This thesis proposes a new tool to analyze and design military vehicle platforms: the Advanced Mobile Integrated Power System (AMPS). This tool is useful for design and design verification of military vehicles due to its unique incorporation of mission-specific functionality. It allows the user ease of design with the ability to customize the vehicle power system architecture and components, while permitting full control over source and load input parameters. Simulation of programmed mission sequences allows the user to ensure that the chosen vehicle architecture can provide all of the electrical power and energy needed to support the mission, thus providing adequate design verification. The present thesis includes an introduction to vehicle power systems and an outline of the need for simulation, a description of the AMPS project and vehicle specifications, analytical and numerical models of the simulated vehicle, explanation of the power management system, description of the graphical user interface, and a simulation performed with the AMPS tool.

Lipscomb, Melissa Anne

2005-08-01T23:59:59.000Z

60

NREL: Dynamic Maps, GIS Data, and Analysis Tools Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

The Dynamic Maps, Geographic Information System (GIS) Data and Analysis The Dynamic Maps, Geographic Information System (GIS) Data and Analysis Tools website provides maps, data and tools for renewable energy resources that determine which energy technologies are viable solutions in domestic and international regions. MapSearch - While this site contains detailed information and quality data, if you want to search for the latest and most up-to-date maps created by NREL, please visit our MapSearch: http://www.nrel.gov/gis/mapsearch/ Renewable Energy Technical Potential with the image of a presentation slide with map. The National Renewable Energy Laboratory's GIS team analyzes wind, solar, biomass, geothermal, and other energy resources and inputs the data into the GIS. Read more about how NREL's GIS staff and capabilities enhance the

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Monte Carlo Simulation Tool Installation and Operation Guide  

Science Conference Proceedings (OSTI)

This document provides information on software and procedures for Monte Carlo simulations based on the Geant4 toolkit, the ROOT data analysis software and the CRY cosmic ray library. These tools have been chosen for its application to shield design and activation studies as part of the simulation task for the Majorana Collaboration. This document includes instructions for installation, operation and modification of the simulation code in a high cyber-security computing environment, such as the Pacific Northwest National Laboratory network. It is intended as a living document, and will be periodically updated. It is a starting point for information collection by an experimenter, and is not the definitive source. Users should consult with one of the authors for guidance on how to find the most current information for their needs.

Aguayo Navarrete, Estanislao; Ankney, Austin S.; Berguson, Timothy J.; Kouzes, Richard T.; Orrell, John L.; Troy, Meredith D.; Wiseman, Clinton G.

2013-09-02T23:59:59.000Z

62

A Quasi-Dynamic HVAC and Building Simulation Methodology  

E-Print Network (OSTI)

This thesis introduces a quasi-dynamic building simulation methodology which complements existing building simulators by allowing transient models of HVAC (heating, ventilating and air-conditioning) systems to be created in an analogous way to their design and simulated in a computationally efficient manner. The methodology represents a system as interconnected, object-oriented sub-models known as components. Fluids and their local properties are modeled using discrete, incompressible objects known as packets. System wide pressure and flow rates are modeled similar to electrical circuit models. Transferring packets between components emulates fluid flow, while the system wide fluid circuit formed by the components' interconnections determines system wide pressures and flow rates. A tool named PAQS, after the PAacketized Quasi-dynamic Simulation methodology, was built to demonstrate the described methodology. Validation tests of PAQS found that its steady state energy use predictions differed less than 3% from a comparable steady state model. PAQS was also able to correctly model the transient behavior of a dynamic linear analytical system.

Davis, Clinton Paul

2012-05-01T23:59:59.000Z

63

Lightweight computational steering of very large scale molecular dynamics simulations  

Science Conference Proceedings (OSTI)

We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages.

Beazley, D.M. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Computer Science; Lomdahl, P.S. [Los Alamos National Lab., NM (United States)

1996-09-01T23:59:59.000Z

64

CgWind: A high-order accurate simulation tool for wind turbines and wind farms  

DOE Green Energy (OSTI)

CgWind is a high-fidelity large eddy simulation (LES) tool designed to meet the modeling needs of wind turbine and wind park engineers. This tool combines several advanced computational technologies in order to model accurately the complex and dynamic nature of wind energy applications. The composite grid approach provides high-quality structured grids for the efficient implementation of high-order accurate discretizations of the incompressible Navier-Stokes equations. Composite grids also provide a natural mechanism for modeling bodies in relative motion and complex geometry. Advanced algorithms such as matrix-free multigrid, compact discretizations and approximate factorization will allow CgWind to perform highly resolved calculations efficiently on a wide class of computing resources. Also in development are nonlinear LES subgrid-scale models required to simulate the many interacting scales present in large wind turbine applications. This paper outlines our approach, the current status of CgWind and future development plans.

Chand, K K; Henshaw, W D; Lundquist, K A; Singer, M A

2010-02-22T23:59:59.000Z

65

Perturbation centrality: a novel centrality measure obtained by the general network dynamics tool, Turbine  

E-Print Network (OSTI)

Analysis of network dynamics became increasingly important to understand the mechanisms and consequences of changes in biological systems from macromolecules to cells and organisms. Currently available network dynamics tools are mostly tailored for specific tasks such as calculation of molecular or neural dynamics. Our Turbine software offers a generic framework enabling the simulation of any algorithmically definable dynamics of any network. Turbine is also optimized for handling very large networks in the range of millions of nodes and edges. Using a perturbation transmission model inspired by communicating vessels, here we introduce a novel centrality measure termed as perturbation centrality. Perturbation centrality is the reciprocal of the time needed to dissipate a starting perturbation in the network. Hubs and inter-modular nodes proved to be highly efficient in perturbation propagation. High perturbation centrality nodes of the Met-tRNA synthetase protein structure network were identified as amino aci...

Szalay, Kristof Z

2013-01-01T23:59:59.000Z

66

Dynamic Simulation of a Helium Liquefier  

SciTech Connect

Dynamic behavior of a helium liquefier has been studied in detail with a Cryogenic Process REal-time SimulaTor (C-PREST) at the National Institute for Fusion Science (NIFS). The C-PREST is being developed to integrate large-scale helium cryogenic plant design, operation and maintenance for optimum process establishment. As a first step of simulations of cooldown to 4.5 K with the helium liquefier model is conducted, which provides a plant-process validation platform. The helium liquefier consists of seven heat exchangers, a liquid-nitrogen (LN2) precooler, two expansion turbines and a liquid-helium (LHe) reservoir. Process simulations are fulfilled with sequence programs, which were implemented with C-PREST based on an existing liquefier operation. The interactions of a JT valve, a JT-bypass valve and a reservoir-return valve have been dynamically simulated. The paper discusses various aspects of refrigeration process simulation, including its difficulties such as a balance between complexity of the adopted models and CPU time.

Maekawa, R.; Ooba, K.; Mito, T. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan); Nobutoki, M. [Nippon Sanso Co., Kawasaki, Kanagawa, 210-0861 (Japan)

2004-06-23T23:59:59.000Z

67

Physics results from dynamical overlap fermion simulations  

E-Print Network (OSTI)

I summarize the physics results obtained from large-scale dynamical overlap fermion simulations by the JLQCD and TWQCD collaborations. The numerical simulations are performed at a fixed global topological sector; the physics results in the theta-vacuum is reconstructed by correcting the finite volume effect, for which the measurement of the topological susceptibility is crucial. Physics applications we studied so far include a calculation of chiral condensate, pion mass, decay constant, form factors, as well as (vector and axial-vector) vacuum polarization functions and nucleon sigma term.

Shoji Hashimoto

2008-11-08T23:59:59.000Z

68

Molecular simulation as a tool for studying lignin  

NLE Websites -- All DOE Office Websites (Extended Search)

Simulation Simulation as a Tool for Studying Lignin Amandeep K. Sangha, a,b Loukas Petridis, a,b Jeremy C. Smith, a,b,c Angela Ziebell, d,e and Jerry M. Parks a,b a UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6309; parksjm@ornl.gov (for correspondence) b BioEnergy Science Center, Oak Ridge, TN c Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, M407 Walters Life Sciences, 1414 Cumberland Avenue, Knoxville, TN 37996 d National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401-3393; angela.ziebell@nrel.gov (for correspondence) e BioEnergy Science Center, Golden, CO Published online 30 December 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ep.10628 Lignocellulosic biomass provides a sustainable source of sugars for biofuel and biomaterial production.

69

Dynamic simulation for IGCC process and control design  

Science Conference Proceedings (OSTI)

Detailed dynamic simulation analysis is a valuable tool that increases the understanding of unit interactions and control system performance in a complex integrated gasification combined-cycle (IGCC) plant. The Sarlux integrated gasification combined cycle (IGCC) plant must simultaneously satisfy electrical power and refinery hydrogen and steam demands (trigeneration gasification). The plant`s gasifier, heat recovery, sulfur removal, hydrogen recovery and steam power generation units are highly integrated and require coordinated control. In this study, dynamic simulation provides insights into the behavior of the process and combined cycle units during normal and upset conditions. The dynamic simulation is used to design a control system that drives the gasifiers to satisfy power, steam and hydrogen demands before a load change or upset is detected by the syngas pressure controller. At the study conclusion, the model will demonstrate how the IGCC plant will respond to the contractual maximum load change rate and process upsets. The study tests the basic process and control system design during the project engineering phase to minimize startup troubleshooting and expensive field changes.

Depew, C.; Martinez, A. [Fluor Daniel, Irvine, CA (United States); Collodi, G.; Meloni, R. [Snamprogetti, Milan (Italy)

1998-01-01T23:59:59.000Z

70

IGCC Dynamic Simulator and Training Center  

SciTech Connect

Integrated Gasification Combined Cycle (IGCC) is emerging as the technology of choice for providing clean, low-cost electricity for the next generation of coal-fired power plants and will play a central role in the development of high-efficiency, zero-emissions power plants such as FutureGen. Several major utilities and developers recently announced plans to build IGCC plants and other major utilities are evaluating IGCC’s suitability for base-load capacity additions. This recent surge of attention to IGCC power generation is creating a growing demand for experience with the analysis, operation, and control of commercial-scale IGCC plants. To meet this need, the National Energy Technology Laboratory (NETL) has launched a project to develop a generic, full-scope, IGCC dynamic plant simulator for use in establishing a state-of-the-art simulator training center at West Virginia University’s (WVU) National Research Center for Coal and Energy (NRCCE). The IGCC Dynamic Simulator & Training (DS&T) Center will be established under the auspices of the Collaboratory for Process & Dynamic Systems Modeling (“Collaboratory”) organized between NETL, WVU, the University of Pittsburgh, and Carnegie Mellon University.

Zitney, S.E.; Erbes, M.R. (Enginomix, LLC)

2006-10-01T23:59:59.000Z

71

Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX  

NLE Websites -- All DOE Office Websites (Extended Search)

Uncertainty Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX X. Hu 1 , A. Passalacqua 2 , R. O. Fox 1 1 Iowa State University, Department of Chemical and Biological Engineering, Ames, IA 2 Iowa State University, Department of Mechanical Engineering, Ames, IA Project Manager: Steve Seachman University Coal Research and Historically Black Colleges and Universities and Other Minority Institutions Contractors Review Conference Pittsburgh, June 11 th - 13 th 2013 X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 1 / 44 Outline 1 Introduction and background 2 Project objectives and milestones 3 Technical progress Univariate case Multivariate case Code structure 4 Future work X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 2 / 44 Introduction and background Outline 1 Introduction

72

LPAT: An interactive simulation tool for assessing the lightning performance of Hellenic high voltage transmission lines  

Science Conference Proceedings (OSTI)

The paper presents the Lightning Performance Assessment Tool (LPAT), an interactive simulation tool which assesses the lightning performance of high voltage transmission lines. The LPAT design was based on a recently published methodology that has been ... Keywords: Lightning performance, Optical transient density, Overhead transmission lines, Simulation, Software tool, User interface

P. Karampelas; L. Ekonomou; S. Panetsos; G. E. Chatzarakis

2011-01-01T23:59:59.000Z

73

A SOFTWARE TOOL TO COMPARE MEASURED AND SIMULATED BUILDING ENERGY...  

NLE Websites -- All DOE Office Websites (Extended Search)

manner, as is typical when using traditional tools. Existing tools often have a steep learning curve (Friedman & Piette 2001) and do not support the needs of the performance...

74

Designing power system simulators for the smart grid: combining controls, communications, and electro-mechanical dynamics  

Science Conference Proceedings (OSTI)

Open source software has a leading role in research on simulation technology for electrical power systems. Research simulators demonstrate new features for which there is nascent but growing demand not yet provided for by commercial simulators. Of particular interest is the inclusion of models of software-intensive and communication-intensive controls in simulations of power system transients. This paper describes two features of the ORNL power system simulator that help it meet this need. First is its use of discrete event simulation for all aspects of the model: control, communication, and electro-mechanical dynamics. Second is an interoperability interface that enables the ORNL power system simulator to be integrated with existing, discrete event simulators of digital communication systems. The paper concludes with a brief discussion of how these aspects of the ORNL power system simulator might be inserted into production-grade simulation tools.

Nutaro, James J [ORNL

2011-01-01T23:59:59.000Z

75

Molecular dynamics simulations of ordered alkane chains physisorbed on graphite  

E-Print Network (OSTI)

Molecular dynamics simulations of ordered alkane chains physisorbed on graphite Reinhard Hentschke molecular axes oriented parallel to the substrate. Here we employ molecular dynamics (MD) simulations to obtain more details on the molecular order and dynamics within the alkane lamellae as a function

Peters, Achim

76

A Modeling Tool for the Precipitation Simulations of Superalloys ...  

Science Conference Proceedings (OSTI)

simulate the complicated precipitations and microstructure .... The kinetic simulation employs three models to treat three ..... Thermochemistry 26, 175 (

77

The Quick Energy Simulation Tool (eQUEST) | Open Energy Information  

Open Energy Info (EERE)

The Quick Energy Simulation Tool (eQUEST) The Quick Energy Simulation Tool (eQUEST) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: eQUEST Agency/Company /Organization: James J. Hirsh & Associates Partner: Lawrence Berkeley National Laboratory (LBNL) Sector: Energy Focus Area: Energy Efficiency, Buildings Phase: Create a Vision, Evaluate Options, Develop Goals, Prepare a Plan Resource Type: Software/modeling tools User Interface: Desktop Application Website: doe2.com/equest/ Cost: Free References: eQUEST[1] The Quick Energy Simulation Tool, or eQUEST, allows users with limited simulation experience to develop 3-dimensional simulation models of a particular building design. These simulations incorporate building location, orientation, wall/roof construction, window properties, as well

78

NREL Developing a Numerical Simulation Tool to Study Hydrokinetic Energy Conversion Devices and Arrays (Fact Sheet)  

Science Conference Proceedings (OSTI)

New code will help accelerate design improvements by providing a high-fidelity simulation tool to study power performance, structural loading, and the interactions between devices in arrays.

Not Available

2012-02-01T23:59:59.000Z

79

Development of simulation tools, control strategies, and a hybrid vehicle prototype .  

E-Print Network (OSTI)

??This thesis (1) reports the development of simulation tools and control strategies for optimizing hybrid electric vehicle (HEV) energy management, and (2) reports the design… (more)

Pei, Dekun

2012-01-01T23:59:59.000Z

80

Molecular dynamics simulation of Li surface erosion and bubble formation  

E-Print Network (OSTI)

Molecular dynamics simulation of Li surface erosion and bubble formation Z. Insepov *, A. Hassanein Structure and dynamical properties of liquid Li containing He atoms were studied by the Molecular Dynamics devices. Molecular dynamics (MD) method is capable of studying important collision processes and providing

Harilal, S. S.

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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81

Summary - System Level Modeling and Simulation Tools for SRS  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Workflo Workflo The ob Proces Savann Dispos assess evaluat design evaluat predict to guid * Th so in w es sy * Th is m * Th fle m de fu The pu techni projec Site: S roject: S Report Date: J ited States valuation i Why DOE ow Diagram bjective of the rev ss Simulation To nah River Site (S sition System Pla s whether the too te methods used , construction, p te methods to im ions; and (4) det e actual executio What th he current Syst oftware tools to formation, and aste. These to stimates, but th ystem planning he capability of limited. This h mid to long-term here is a need exibility, and tu model prediction ecouple safety unctions. To view the full E http://www.em.doe. urpose of an Externa ical risk associated w ct decisions. Technic Savannah Rive SRS System M June 2009 Departmen n of Sys n Suppo E-EM Did This view was to eva

82

Molecular Dynamics Simulations of Microscale Fluid Transport  

E-Print Network (OSTI)

Recent advances in micro-science and technology, like Micro-ElectroMechanical Systems (MEMS), have generated a group of unique liquid flow problems that involve characteristic length scales of a micron. Also, in manufacturing processes such as coatings, current continuum models are unable to predict microscale physical phenomena that appear in these nonequilibrium systems. It is suspected that in these systems, molecular-level processes can control the interfacial energy and viscoelastic properties at the liquid/solid boundary. A massively parallel molecular dynamics (MD) code has been developed to better understand microscale transport mechanisms, fluid-structure interactions, and scale effects in micro-domains. Specifically, this MD code has been used to analyze liquid channel flow problems for a variety of channel widths, e.g. 0.005-0.05 microns. This report presents results from MD simulations of Poiseuille flow and Couette flow problems and address both scaling and modeling issues...

C. C. Wong; A. R. Lopez; M.J. Stevens; S. J. Plimpton; Category Uc; Like Micro-electro

1998-01-01T23:59:59.000Z

83

Kinetic Simulations of Fusion Energy Dynamics at the Extreme...  

NLE Websites -- All DOE Office Websites (Extended Search)

Kinetic Simulations of Fusion Energy Dynamics at the Extreme Scale PI Name: William Tang PI Email: tang@pppl.gov Institution: Princeton Plasma Physics Laboratory Allocation...

84

Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum ...  

Science Conference Proceedings (OSTI)

Dubal Cell Voltage Drop Initiatives towards Low Energy High Amperage Cells · Dynamic Simulation of Cell Voltage Resonance Effect in Aluminum Electrolysis ...

85

Computational Fluid Dynamic Simulations of a Regenerative Process...  

NLE Websites -- All DOE Office Websites (Extended Search)

Fluid Dynamic Simulations of a Regenerative Process for Carbon Dioxide Capture in Advanced Gasification Based Power Systems Background The Department of Energy (DOE) National...

86

Molecular Statics and Molecular Dynamics Simulations of the ...  

Science Conference Proceedings (OSTI)

Presentation Title, Molecular Statics and Molecular Dynamics Simulations of the Critical Stress for Motion of a/3 Screw Dislocations in a-Ti at Low ...

87

Molecular Dynamics Simulation of Cavitation in Metallic Glass  

Science Conference Proceedings (OSTI)

We have undertaken a series of molecular dynamics simulations of cavitation under hydrostatic tension in a binary metallic glass analog using pair-wise ...

88

Two-Dimensional Computational Fluid Dynamics and Conduction Simulation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities Title Two-Dimensional Computational...

89

Avestar® - Integrated Gasification Combined Cycle (IGCC) Dynamic Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Integrated Gasification Combined Cycle (IGCC) Dynamic Simulator Integrated Gasification Combined Cycle (IGCC) Dynamic Simulator The AVESTAR® center offers courses using the Integrated Gasification Combined Cycle (IGCC) Dynamic Simulator. The IGCC simulator builds on and reaches beyond existing combined-cycle and conventional-coal power plant simulators to combine--for the first time--a Gasification with CO2 Capture process simulator with a Combined-Cycle power simulator together in a single dynamic simulation framework. The AVESTAR® center IGCC courses provide unique, comprehensive training on all aspects of an IGCC plant, illustrating the high-efficiency aspects of the gasifier, gas turbine, and steam turbine integration. IGCC Operator training station HMI display for overview of IGCC Plant - Train A Reference:

90

Abaqus Simulations of Rock Response to Dynamic Loading  

SciTech Connect

The LANL Geodynamics Team has been applying Abaqus modeling to achieve increasingly complex simulations. Advancements in Abaqus model building and simulation tools allows this progress. We use Lab-developed constitutive models, the fully coupled CEL Abaqus and general contact to simulate response of realistic sites to explosively driven shock.

Steedman, David W. [Los Alamos National Laboratory; Coblentz, David [Los Alamos National Laboratory

2012-08-15T23:59:59.000Z

91

Molecular dynamics simulations and drug discovery  

E-Print Network (OSTI)

JE: On the determination of molecular fields. II. From thescalability for parallel molecular dynamics. J Comput PhysKale L, Schulten K: Scalable molecular dynamics with NAMD. J

Durrant, Jacob D; McCammon, J Andrew

2011-01-01T23:59:59.000Z

92

Development of Design and Simulation Tool for Hybrid Geothermal...  

Open Energy Info (EERE)

and Analysis Project Description eQUEST is a widely accepted building and HVAC system energy analysis tool (freeware) that is powered with the latest implementation of the...

93

Exploiting hierarchical parallelisms for molecular dynamics simulation on multicore clusters  

Science Conference Proceedings (OSTI)

We have developed a scalable hierarchical parallelization scheme for molecular dynamics (MD) simulation on multicore clusters. The scheme explores multilevel parallelism combining: (1) Internode parallelism using spatial decomposition via message passing; ... Keywords: Molecular dynamics simulation, Multicore cluster, Scalable hierarchical parallelization scheme, Single instruction multiple data

Liu Peng; Manaschai Kunaseth; Hikmet Dursun; Ken-Ichi Nomura; Weiqiang Wang; Rajiv K. Kalia; Aiichiro Nakano; Priya Vashishta

2011-07-01T23:59:59.000Z

94

Anton, a special-purpose machine for molecular dynamics simulation  

Science Conference Proceedings (OSTI)

The ability to perform long, accurate molecular dynamics (MD) simulations involving proteins and other biological macro-molecules could in principle provide answers to some of the most important currently outstanding questions in the fields of biology, ... Keywords: bioinformatics, biomolecular system simulation, computational biology, computational drug design, molecular dynamics, protein folding, protein structure, special-purpose machine

David E. Shaw; Martin M. Deneroff; Ron O. Dror; Jeffrey S. Kuskin; Richard H. Larson; John K. Salmon; Cliff Young; Brannon Batson; Kevin J. Bowers; Jack C. Chao; Michael P. Eastwood; Joseph Gagliardo; J. P. Grossman; C. Richard Ho; Douglas J. Ierardi; István Kolossváry; John L. Klepeis; Timothy Layman; Christine McLeavey; Mark A. Moraes; Rolf Mueller; Edward C. Priest; Yibing Shan; Jochen Spengler; Michael Theobald; Brian Towles; Stanley C. Wang

2007-06-01T23:59:59.000Z

95

Design of an Enterprise Dynamic Performance Simulation and Analysis System  

Science Conference Proceedings (OSTI)

Many problems in enterprise running faced by managers can be resolved by simulation of the corresponding system dynamics model. It is often desirable to forecasting enterprise running in the next period. And managers hope to find the reason quickly if ... Keywords: dynamic performance, simulation, sensitivity, diagnose, performance optimization

Zheng Li; Yueting Chai; Yi Liu

2011-04-01T23:59:59.000Z

96

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

F N P Tool Applications Free Recently Updated Flownex gas flow; liquid flow; dynamic; heat transfer; two phase; slurry NewQUICK Passive simulation, load calculations, natural...

97

AVESTAR® - Natural Gas Combined Cycle (NGCC) Dynamic Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Natural Gas Combined Cycle (NGCC) Dynamic Simulator Natural Gas Combined Cycle (NGCC) Dynamic Simulator A simulator that can provide future engineers with realistic, hands-on experience for operating advanced natural gas combined cycle (NGCC) power plants will soon be available at an innovative U.S. Department of Energy training center. Under a new cooperative research and development agreement signed by the Office of Fossil Energy's National Energy Technology Laboratory (NETL) and Invensys Operations Management, the partners will develop, test, and deploy a dynamic simulator and operator training system (OTS) for a generic NGCC power plant equipped for use with post-combustion carbon capture. NETL will operate the new dynamic simulator/OTS at the AVESTAR (Advanced Virtual Energy Simulation Training and Research) Center in Morgantown, W.Va.

98

Advancing lighting and daylighting simulation: The transition from analysis to design aid tools  

SciTech Connect

This paper explores three significant software development requirements for making the transition from stand-alone lighting simulation/analysis tools to simulation-based design aid tools. These requirements include specialized lighting simulation engines, facilitated methods for creating detailed simulatable building descriptions, an automated techniques for providing lighting design guidance. Initial computer implementations meant to address each of these requirements are discussed to further elaborate these requirements and to illustrate work-in-progress.

Hitchcock, R.J.

1995-05-01T23:59:59.000Z

99

Simulation of chemical reaction dynamics on an NMR quantum computer  

E-Print Network (OSTI)

Quantum simulation can beat current classical computers with minimally a few tens of qubits and will likely become the first practical use of a quantum computer. One promising application of quantum simulation is to attack challenging quantum chemistry problems. Here we report an experimental demonstration that a small nuclear-magnetic-resonance (NMR) quantum computer is already able to simulate the dynamics of a prototype chemical reaction. The experimental results agree well with classical simulations. We conclude that the quantum simulation of chemical reaction dynamics not computable on current classical computers is feasible in the near future.

Dawei Lu; Nanyang Xu; Ruixue Xu; Hongwei Chen; Jiangbin Gong; Xinhua Peng; Jiangfeng Du

2011-05-21T23:59:59.000Z

100

Development of CFD-Based Simulation Tools for In-Situ Thermal Processing of Oil Shale/Sands  

Science Conference Proceedings (OSTI)

In our research, we are taking the novel approach of developing and applying high performance computing, computational fluid dynamics (CFD)-based simulation tools to a modified in-situ process for production of oil from oil shale. The simulation tools being developed capture the relevant physical processes and data from a large-scale system. The modified in-situ application is a pilot-scale heat transfer process inside Red Leaf Resourcesâ?? EcoShale capsule. We demonstrate the need to understand fluid flow behavior in the convective channels of the rubblized shale bed as convective heating greatly decreases the time required to heat the oil shale to the production temperature when compared with conductive heating alone. We have developed and implemented a geometry creation strategy for a representative section of the EcoShale capsule, developed a meshing approach to deal with the complicated geometry and produce a well-behaved mesh, analyzed the effects of boundary conditions on the simulation results, and devised a new operator splitting solution algorithm that reduces computational costs by taking advantage of the differing convective and conductive time scales occurring in the simulation. These simulation tools can be applied to a wide range of processes involving convective fluid flow heating in rubblized beds.

None

2012-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Molecular Dynamics Simulations of Thermoset Polymers for ...  

Science Conference Proceedings (OSTI)

Materials Genomics Past & Future: From CALPHAD to Flight · Modelling the Properties of Multi-Component Commercial Alloys · Molecular Dynamics ...

102

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Hydrogen Maps  

NLE Websites -- All DOE Office Websites (Extended Search)

Donna Heimiller (2005). For more information on hydrogen resources, access the Hydrogen Energy Analysis and Tools site. For Geographic Information System (GIS) hydrogen resource...

103

DFT-based molecular dynamics as a new tool for computational biology: first applications and perspective  

Science Conference Proceedings (OSTI)

Static and molecular dynamics (MD) calculations based on density-functional theory (DFT) are emerging as a valuable means for simulations in the field of biology, especially when coupled with classical simulations. In this contribution, we point out ...

W. Andreoni; A. Curioni; T. Mordasini

2001-05-01T23:59:59.000Z

104

Application of Various HVAC Simulation Programs and Visual Tools to Commissioning  

E-Print Network (OSTI)

Various existing HVAC system simulation programs and visualization tools are considered to be potentially powerful tools for commissioning. Although not originally developed as commissioning tools, these programs facilitate the confirmation/comparison of HVAC system function and performance and enable detailed analysis of parameters influencing HVAC system performance. This paper investigates the functionality and ease of use of several such programs in support of the commissioning process. The investigation and assessment of simulation programs includes: Micro HASP, Micro ACSS, FACES, LCEM, HVACSIM+, TRNSYS, DOE-2, EnergyPlus and DeST and their visual tools.

Zheng, M.; Pan, S.

2007-01-01T23:59:59.000Z

105

Computer Simulations of Protein Dynamics and Thermodynamics  

Science Conference Proceedings (OSTI)

The computational challenges of producing realistic biomedical simulations are reviewed. Techniques for applying classical mechanics simulation methods to proteins and ways to solve Newton's equations are discussed. Two recent applications of these methods ...

David Case

1993-10-01T23:59:59.000Z

106

NREL Developing Numerical Simulation Tool to Study Hydrokinetic...  

NLE Websites -- All DOE Office Websites (Extended Search)

M.; Li, Y.; Moriarty, P. (2012). "A Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines." Accepted by Proceedings of the...

107

Avestar® - Syngas-Fired Combined Cycle Dynamic Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Syngas-Fired Combined Cycle Dynamic Simulator Syngas-Fired Combined Cycle Dynamic Simulator The AVESTAR® center offers courses using the Combined Cycle Simulator, focusing on the power generation process after gasification. This simulator is well-suited for concentrated training on operation and control of the gas and steam turbines; condensate, feed water, and circulating water systems; heat recovery steam generator; and selective catalytic reduction (SCR) unit. Combined cycle simulator startup operations include bringing up the gas turbine to rated speed on natural gas and then switching over to the firing of synthesis gas. Key capabilities of the Combined Cycle Simulator include: Combined Cycle Simulator Operator training station HMI display for overview of Gas Turbine - Train A Normal base load operation

108

Simulated Convective Lines with Leading Precipitation. Part I: Governing Dynamics  

Science Conference Proceedings (OSTI)

This article, the first of two describing a study in which the authors used idealized numerical simulations to investigate convective lines with leading precipitation, addresses the dynamics governing the systems' structures and individual air ...

Matthew D. Parker; Richard H. Johnson

2004-07-01T23:59:59.000Z

109

Dynamical Effects of Aerosol Perturbations on Simulated Idealized Squall Lines  

Science Conference Proceedings (OSTI)

The dynamical effects of increased aerosol loading on the strength and structure of numerically simulated squall lines are explored. Results are explained in the context of RKW theory. Changes in aerosol loading lead to changes in rain drop size ...

Zachary J. Lebo; Hugh Morrison

110

Simulation of the dynamic response of a damped taught string  

E-Print Network (OSTI)

Marine pipeline are facing new issues involved by the increase of the depth of exploited oil and gas reservoirs. This thesis discusses the changes in the dynamic behavior of marine pipelines and proposes a simple simulation ...

Favennec, Hervé

2007-01-01T23:59:59.000Z

111

Molecular Dynamics Simulations of Vacancy and Oxygen Diffusion ...  

Science Conference Proceedings (OSTI)

A Tale of Two States and More: Modeling of New Generation of Lattice Stability from Zero ... Analysis of Nano Fluid Using CFD-A Hybrid Approach for Cooling Purpose ... Molecular Dynamics Simulations of Grain Boundary Free Energy and

112

Millisecond-scale molecular dynamics simulations on Anton  

Science Conference Proceedings (OSTI)

Anton is a recently completed special-purpose supercomputer designed for molecular dynamics (MD) simulations of biomolecular systems. The machine's specialized hardware dramatically increases the speed of MD calculations, making possible for the first ...

David E. Shaw; Ron O. Dror; John K. Salmon; J. P. Grossman; Kenneth M. Mackenzie; Joseph A. Bank; Cliff Young; Martin M. Deneroff; Brannon Batson; Kevin J. Bowers; Edmond Chow; Michael P. Eastwood; Douglas J. Ierardi; John L. Klepeis; Jeffrey S. Kuskin; Richard H. Larson; Kresten Lindorff-Larsen; Paul Maragakis; Mark A. Moraes; Stefano Piana; Yibing Shan; Brian Towles

2009-11-01T23:59:59.000Z

113

Anton, a special-purpose machine for molecular dynamics simulation  

Science Conference Proceedings (OSTI)

The ability to perform long, accurate molecular dynamics (MD) simulations involving proteins and other biological macro-molecules could in principle provide answers to some of the most important currently outstanding questions in the fields of biology, ...

David E. Shaw; Martin M. Deneroff; Ron O. Dror; Jeffrey S. Kuskin; Richard H. Larson; John K. Salmon; Cliff Young; Brannon Batson; Kevin J. Bowers; Jack C. Chao; Michael P. Eastwood; Joseph Gagliardo; J. P. Grossman; C. Richard Ho; Douglas J. Ierardi; István Kolossváry; John L. Klepeis; Timothy Layman; Christine McLeavey; Mark A. Moraes; Rolf Mueller; Edward C. Priest; Yibing Shan; Jochen Spengler; Michael Theobald; Brian Towles; Stanley C. Wang

2008-07-01T23:59:59.000Z

114

Physics issues in simulations with dynamical overlap fermions  

E-Print Network (OSTI)

We discuss the impact of various improvements on simulations of dynamical overlap fermions using the Hybrid Monte Carlo algorithm. We focus on the usage of fat links and multiple pseudo-fermion fields.

Thomas DeGrand; Stefan Schaefer

2004-12-01T23:59:59.000Z

115

Nonequilibrium candidate Monte Carlo: A new tool for efficient equilibrium simulation  

SciTech Connect

Metropolis Monte Carlo simulation is a powerful tool for studying the equilibrium properties of matter. In complex condensed-phase systems, however, it is difficult to design Monte Carlo moves with high acceptance probabilities that also rapidly sample uncorrelated configurations. Here, we introduce a new class of moves based on nonequilibrium dynamics: candidate configurations are generated through a finite-time process in which a system is actively driven out of equilibrium, and accepted with criteria that preserve the equilibrium distribution. The acceptance rule is similar to the Metropolis acceptance probability, but related to the nonequilibrium work rather than the instantaneous energy difference. Our method is applicable to sampling from both a single thermodynamic state or a mixture of thermodynamic states, and allows both coordinates and thermodynamic parameters to be driven in nonequilibrium proposals. While generating finite-time switching trajectories incurs an additional cost, driving some degrees of freedom while allowing others to evolve naturally can lead to large enhancements in acceptance probabilities, greatly reducing structural correlation times. Using nonequilibrium driven processes vastly expands the repertoire of useful Monte Carlo proposals in simulations of dense solvated systems.

Nilmeier, Jerome P.; Crooks, Gavin E.; Minh, David D. L.; Chodera, John D.

2011-11-08T23:59:59.000Z

116

Numerical simulation of high-speed penetration-perforation dynamics in layered armor shields  

E-Print Network (OSTI)

Penetration models and calculating algorithms are presented, describing the dynamics and fracture of composite armor shields penetrated by high-speed small arms. A shield considered consists of hard (metal or ceramic) facing and multilayered fabric backing. A simple formula is proved for the projectile residual velocity after perforation of a thin facing. A new plastic-flow jet model is proposed for calculating penetration dynamics in the case of a thick facing of ceramic or metal-ceramic FGM materials. By bringing together the developed models into a calculating algorithm, a computer tool is designed enabling simulations of penetration processes in the above-mentioned shields and analysis of optimization problems. Some results of computer simulation are presented. It is revealed in particular that strength proof of pliable backing can be better as compared with more rigid backing. Comparison of calculations and test data shows sufficient applicability of the models and the tool.

Ayzenberg-Stepanenko, Mark

2012-01-01T23:59:59.000Z

117

Numerical simulation of high-speed penetration-perforation dynamics in layered armor shields  

E-Print Network (OSTI)

Penetration models and calculating algorithms are presented, describing the dynamics and fracture of composite armor shields penetrated by high-speed small arms. A shield considered consists of hard (metal or ceramic) facing and multilayered fabric backing. A simple formula is proved for the projectile residual velocity after perforation of a thin facing. A new plastic-flow jet model is proposed for calculating penetration dynamics in the case of a thick facing of ceramic or metal-ceramic FGM materials. By bringing together the developed models into a calculating algorithm, a computer tool is designed enabling simulations of penetration processes in the above-mentioned shields and analysis of optimization problems. Some results of computer simulation are presented. It is revealed in particular that strength proof of pliable backing can be better as compared with more rigid backing. Comparison of calculations and test data shows sufficient applicability of the models and the tool.

Mark Ayzenberg-Stepanenko; Grigory Osharovich

2012-03-07T23:59:59.000Z

118

Dynamic wind turbine models in power system simulation tool  

E-Print Network (OSTI)

.2.1.2 Doubly-fed induction generator (DFIG) 13 2.2.1.3 Synchronous generator 15 2.2.2 Power converters 18 2

119

A PRODUCTION SIMULATION TOOL FOR SYSTEMS WITH INTEGRATED WIND ENERGY RESOURCES  

E-Print Network (OSTI)

A PRODUCTION SIMULATION TOOL FOR SYSTEMS WITH INTEGRATED WIND ENERGY RESOURCES BY NICOLAS BENOIT the energy output of a wind farm in a single location and of those in multiple locations. In this way, we for such planning tools. The incorporation of the wind energy model requires the extension of the widely used

Gross, George

120

Development of a dynamic simulator for a natural gas combined cycle (NGCC) power plant with post-combustion carbon capture  

Science Conference Proceedings (OSTI)

The AVESTAR Center located at the U.S. Department of Energy’s National Energy Technology Laboratory and West Virginia University is a world-class research and training environment dedicated to using dynamic process simulation as a tool for advancing the safe, efficient and reliable operation of clean energy plants with CO{sub 2} capture. The AVESTAR Center was launched with a high-fidelity dynamic simulator for an Integrated Gasification Combined Cycle (IGCC) power plant with pre-combustion carbon capture. The IGCC dynamic simulator offers full-scope Operator Training Simulator (OTS) Human Machine Interface (HMI) graphics for realistic, real-time control room operation and is integrated with a 3D virtual Immersive Training Simulator (ITS), thus allowing joint control room and field operator training. The IGCC OTS/ITS solution combines a “gasification with CO{sub 2} capture” process simulator with a “combined cycle” power simulator into a single high-performance dynamic simulation framework. This presentation will describe progress on the development of a natural gas combined cycle (NGCC) dynamic simulator based on the syngas-fired combined cycle portion of AVESTAR’s IGCC dynamic simulator. The 574 MW gross NGCC power plant design consisting of two advanced F-class gas turbines, two heat recovery steam generators (HRSGs), and a steam turbine in a multi-shaft 2x2x1 configuration will be reviewed. Plans for integrating a post-combustion carbon capture system will also be discussed.

Liese, E.; Zitney, S.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Simulation as a support tool for training logistic operators  

Science Conference Proceedings (OSTI)

Ports play a very important role in the economy of a nation, as well as other crucial infrastructures like railways, motorways and airports, because, if managed properly, can significantly increase the competitiveness of a particular area. For this reason ... Keywords: CBT (computer based training) logistics, VV&A (validation, verification and accreditation), simulation, virtual reality

Enrico Briano; Claudia Caballini

2012-02-01T23:59:59.000Z

122

A simulation tool for automated platooning in mixed highway scenarios  

Science Conference Proceedings (OSTI)

Automated platooning is one of the most challenging fields in the domain of ITS. Conceptually, platooning means creating clusters of vehicles which closely follow each other autonomously without action of the driver, neither for accelerating, nor for ... Keywords: cooperative adaptive cruise control, platooning, simulation, vehicular networks

Michele Segata; Falko Dressler; Renato Lo Cigno; Mario Gerla

2012-08-01T23:59:59.000Z

123

Better HMC integrators for dynamical simulations  

SciTech Connect

We show how to improve the molecular dynamics step of Hybrid Monte Carlo, both by tuning the integrator using Poisson brackets measurements and by the use of force gradient integrators. We present results for moderate lattice sizes.

M.A. Clark, Balint Joo, A.D. Kennedy, P.J. Silva

2010-06-01T23:59:59.000Z

124

Dynamic electrothermal simulation of integrated resistors at device level  

Science Conference Proceedings (OSTI)

This paper presents the dynamic electrothermal simulation of a rectangular resistor integrated on a semi-conductor substrate. Due to the temperature dependence of the electrical conductivity of the resistive sheet, self-heating provokes a coupling between ... Keywords: Electrothermal simulation, Nonlinearity, Structure functions, Thermal impedance, Transient

B. Vermeersch; G. De Mey

2009-09-01T23:59:59.000Z

125

Phase-field Simulations/Molecular Dynamics  

Science Conference Proceedings (OSTI)

The sharp interface model was used to determine the SLI free energy and its anisotropy by fitting to the MD data. Finally, the MD simulation of the B2 growth ...

126

Summary - System Level Modeling and Simulation Tools for Hanford  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The ob The ob curren plannin Dispos yield re to mod plannin to imp (4) det actual * Th th Th co no in pl * In fo op sy as di re de co an * Th en m ha ev sc The pu techni projec Site: H roject: H Report Date: S ited States valuation in Su Why DOE bjective of the r nt Process Simu ng basis for OR sition System P easonable esti del facilities cur ng or operation rove the rate o termine if addit execution of in What th he current Syst hat are limited t hese tools curr omposition, res ot meeting was itial batches. T anning tool tha ncomplete sync or tank farm ope peration (G2 dy ystem analysis ssumptions use fferent. HTWO esults in the sys esign/operation onsequence tim nalyzed. he lack of an "o ntire plant/proc maintainability (R ampers life cyc valuate system cenarios to imp To view the full E http://www.em.doe. urpose of an Externa

127

Evaluation of four artificial lighting simulation tools with virtual building reference  

Science Conference Proceedings (OSTI)

There are number of software environment available to provide physically accurate lighting simulation to support lighting researchers and designers. This paper compares and analyses performance of four lighting simulation programs (AGI32, DIALux, RADIANCE ... Keywords: CIE test case, artificial lighting, evaluation, tools, validation

Shariful Shikder

2009-07-01T23:59:59.000Z

128

Programmable quantum simulation by dynamic Hamiltonian engineering  

E-Print Network (OSTI)

Quantum simulation is a promising near term application for mesoscale quantum information processors, with the potential to solve computationally intractable problems at the scale of just a few dozen interacting quantum systems. Recent experiments in a range of technical platforms have demonstrated the basic functionality of quantum simulation applied to quantum magnetism, quantum phase transitions, and relativistic quantum mechanics. In all cases, the underlying hardware platforms restrict the achievable inter-particle interaction, forming a serious constraint on the ability to realize a versatile, programmable, quantum simulator. In this work, we address this problem by developing novel sequences of unitary operations that engineer desired effective Hamiltonians in the time-domain. The result is a hybrid programmable analog simulator permitting a broad class of interacting spin-lattice models to be generated starting only with an arbitrary native inter-particle interaction and single-qubit addressing. Building on previous work proving that universal simulation is possible using both entangling gates and single-qubit unitaries, we show how determining the relevant hardware "program" of unitary pulses to implement an arbitrary spin Hamiltonian on such a simulator can be formulated as a linear program that runs in polynomial time and scales efficiently in hardware resources. Our analysis extends from circuit model quantum information to adiabatic quantum evolutions, where our approach allows for the creation of non-native ground state solutions to a computation.

David L. Hayes; Steven T. Flammia; Michael J. Biercuk

2013-09-26T23:59:59.000Z

129

Final report on LDRD project: Simulation/optimization tools for system variability analysis  

SciTech Connect

>This work was conducted during FY98 (Proposal Number 98-0036) and FY99 (Proposal Number 99-0818) under the auspices of the Sandia National Laboratories Laboratory-Directed Research and Development (LDRD) program. Electrical simulation typically treats a single data point in the very large input space of component properties. For electrical simulation to reach its full potential as a design tool, it must be able to address the unavoidable variability and uncertainty in component properties. Component viability is strongly related to the design margin (and reliability) of the end product. During the course of this project, both tools and methodologies were developed to enable analysis of variability in the context of electrical simulation tools. Two avenues to link relevant tools were also developed, and the resultant toolset was applied to a major component.

R. L. Bierbaum; R. F. Billau; J. E. Campbell; K. D. Marx; R. J. Sikorski; B. M. Thompson; S. D. Wix

1999-10-01T23:59:59.000Z

130

Modeling ramp compression experiments using large-scale molecular dynamics simulation.  

Science Conference Proceedings (OSTI)

Molecular dynamics simulation (MD) is an invaluable tool for studying problems sensitive to atomscale physics such as structural transitions, discontinuous interfaces, non-equilibrium dynamics, and elastic-plastic deformation. In order to apply this method to modeling of ramp-compression experiments, several challenges must be overcome: accuracy of interatomic potentials, length- and time-scales, and extraction of continuum quantities. We have completed a 3 year LDRD project with the goal of developing molecular dynamics simulation capabilities for modeling the response of materials to ramp compression. The techniques we have developed fall in to three categories (i) molecular dynamics methods (ii) interatomic potentials (iii) calculation of continuum variables. Highlights include the development of an accurate interatomic potential describing shock-melting of Beryllium, a scaling technique for modeling slow ramp compression experiments using fast ramp MD simulations, and a technique for extracting plastic strain from MD simulations. All of these methods have been implemented in Sandia's LAMMPS MD code, ensuring their widespread availability to dynamic materials research at Sandia and elsewhere.

Mattsson, Thomas Kjell Rene; Desjarlais, Michael Paul; Grest, Gary Stephen; Templeton, Jeremy Alan; Thompson, Aidan Patrick; Jones, Reese E.; Zimmerman, Jonathan A.; Baskes, Michael I. (University of California, San Diego); Winey, J. Michael (Washington State University); Gupta, Yogendra Mohan (Washington State University); Lane, J. Matthew D.; Ditmire, Todd (University of Texas at Austin); Quevedo, Hernan J. (University of Texas at Austin)

2011-10-01T23:59:59.000Z

131

NREL Evaluates Thermal Performance of Uninsulated Walls to Improve Accuracy of Building Energy Simulation Tools (Fact Sheet)  

SciTech Connect

NREL researchers discover ways to increase accuracy in building energy simulations tools to improve predictions of potential energy savings in homes. Uninsulated walls are typical in older U.S. homes where the wall cavities were not insulated during construction or where the insulating material has settled. Researchers at the National Renewable Energy Laboratory (NREL) are investigating ways to more accurately calculate heat transfer through building enclosures to verify the benefit of energy efficiency upgrades that reduce energy use in older homes. In this study, scientists used computational fluid dynamics (CFD) analysis to calculate the energy loss/gain through building walls and visualize different heat transfer regimes within the uninsulated cavities. The effects of ambient outdoor temperature, the radiative properties of building materials, insulation levels, and the temperature dependence of conduction through framing members were considered. The research showed that the temperature dependence of conduction through framing members dominated the differences between this study and previous results - an effect not accounted for in existing building energy simulation tools. The study provides correlations for the resistance of the uninsulated assemblies that can be implemented into building simulation tools to increase the accuracy of energy use estimates in older homes, which are currently over-predicted.

2012-03-01T23:59:59.000Z

132

NREL Evaluates the Thermal Performance of Uninsulated Walls to Improve the Accuracy of Building Energy Simulation Tools (Fact Sheet)  

SciTech Connect

This technical highlight describes NREL research to develop models of uninsulated wall assemblies that help to improve the accuracy of building energy simulation tools when modeling potential energy savings in older homes. Researchers at the National Renewable Energy Laboratory (NREL) have developed models for evaluating the thermal performance of walls in existing homes that will improve the accuracy of building energy simulation tools when predicting potential energy savings of existing homes. Uninsulated walls are typical in older homes where the wall cavities were not insulated during construction or where the insulating material has settled. Accurate calculation of heat transfer through building enclosures will help determine the benefit of energy efficiency upgrades in order to reduce energy consumption in older American homes. NREL performed detailed computational fluid dynamics (CFD) analysis to quantify the energy loss/gain through the walls and to visualize different airflow regimes within the uninsulated cavities. The effects of ambient outdoor temperature, radiative properties of building materials, and insulation level were investigated. The study showed that multi-dimensional airflows occur in walls with uninsulated cavities and that the thermal resistance is a function of the outdoor temperature - an effect not accounted for in existing building energy simulation tools. The study quantified the difference between CFD prediction and the approach currently used in building energy simulation tools over a wide range of conditions. For example, researchers found that CFD predicted lower heating loads and slightly higher cooling loads. Implementation of CFD results into building energy simulation tools such as DOE2 and EnergyPlus will likely reduce the predicted heating load of homes. Researchers also determined that a small air gap in a partially insulated cavity can lead to a significant reduction in thermal resistance. For instance, a 4-in. tall air gap (Figure 1a) led to a 15% reduction in resistance. Similarly, a 2-ft tall air gap (Figure 1c) led to 54% reduction in thermal resistance. NREL researchers plan to extend this study to include additional wall configurations, and also to evaluate the performance of attic spaces with different insulation levels. NREL's objective is to address each potential issue that leads to inaccuracies in building energy simulation tools to improve the predictions.

Not Available

2012-01-01T23:59:59.000Z

133

NREL Evaluates the Thermal Performance of Uninsulated Walls to Improve the Accuracy of Building Energy Simulation Tools (Fact Sheet)  

SciTech Connect

This technical highlight describes NREL research to develop models of uninsulated wall assemblies that help to improve the accuracy of building energy simulation tools when modeling potential energy savings in older homes. Researchers at the National Renewable Energy Laboratory (NREL) have developed models for evaluating the thermal performance of walls in existing homes that will improve the accuracy of building energy simulation tools when predicting potential energy savings of existing homes. Uninsulated walls are typical in older homes where the wall cavities were not insulated during construction or where the insulating material has settled. Accurate calculation of heat transfer through building enclosures will help determine the benefit of energy efficiency upgrades in order to reduce energy consumption in older American homes. NREL performed detailed computational fluid dynamics (CFD) analysis to quantify the energy loss/gain through the walls and to visualize different airflow regimes within the uninsulated cavities. The effects of ambient outdoor temperature, radiative properties of building materials, and insulation level were investigated. The study showed that multi-dimensional airflows occur in walls with uninsulated cavities and that the thermal resistance is a function of the outdoor temperature - an effect not accounted for in existing building energy simulation tools. The study quantified the difference between CFD prediction and the approach currently used in building energy simulation tools over a wide range of conditions. For example, researchers found that CFD predicted lower heating loads and slightly higher cooling loads. Implementation of CFD results into building energy simulation tools such as DOE2 and EnergyPlus will likely reduce the predicted heating load of homes. Researchers also determined that a small air gap in a partially insulated cavity can lead to a significant reduction in thermal resistance. For instance, a 4-in. tall air gap (Figure 1a) led to a 15% reduction in resistance. Similarly, a 2-ft tall air gap (Figure 1c) led to 54% reduction in thermal resistance. NREL researchers plan to extend this study to include additional wall configurations, and also to evaluate the performance of attic spaces with different insulation levels. NREL's objective is to address each potential issue that leads to inaccuracies in building energy simulation tools to improve the predictions.

2012-01-01T23:59:59.000Z

134

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Data Visualization &  

NLE Websites -- All DOE Office Websites (Extended Search)

MapSearch Searching for maps has never been easier. A screen capture of the MapSearch Map view option Bookmark and Share Data Visualization & Geospatial Tools NREL's Geographic Information System (GIS) Team has developed tools that allow users to apply these data. These tools help determine things such as how much electricity can be produced from solar systems on a house or what renewable resources are available in a specific areas. Please visit http://maps.nrel.gov/ for the most current list of available NREL's GIS tools. If you have difficulty using these tools because of a disability, please contact the Webmaster. General Interactive Mapping Tools Access RE Atlas, Solar Power Prospector, PVWatts, and other popular tools that dynamically generate maps of renewable energy resources.

135

DHARMA: A Tool for Evaluating Dynamic Scheduling Algorithms for Real-time Multiprocessor Systems  

E-Print Network (OSTI)

A majority of today's real-time systems assume a priori knowledge of task characteristics and hence are based on static designs which contribute to their high cost and inflexibility. The next generation hard real-time systems must be designed to be dynamic and flexible. This provides the motivation to study various dynamic scheduling proposals. In this paper, we discuss the design and implementation of a tool, called DHARMA, which is an attempt towards satisfying such requirements. The tool provides an environment to study various dynamic scheduling algorithms with or without fault-tolerance requirements and associated resource reclaiming algorithms in a multiprocessor real-time system.

G. Manimaran; Anand Manikutty; C. Siva Ram Murthy

1998-01-01T23:59:59.000Z

136

Simulating the dynamics of auroral phenomena  

Science Conference Proceedings (OSTI)

Simulating natural phenomena has always been a focal point for computer graphics research. Its importance goes beyond the production of appealing presentations, since research in this area can contribute to the scientific understanding of complex natural ... Keywords: Atmospheric effects, natural phenomena, plasma phenomena, rendering

Gladimir V. G. Baranoski; Justin Wan; Jon G. Rokne; Ian Bell

2005-01-01T23:59:59.000Z

137

Ensemble Simulations with Coupled Atmospheric Dynamic and Dispersion Models: Illustrating Uncertainties in Dosage Simulations  

Science Conference Proceedings (OSTI)

Ensemble simulations made using a coupled atmospheric dynamic model and a probabilistic Lagrangian puff dispersion model were employed in a forensic analysis of the transport and dispersion of a toxic gas that may have been released near Al ...

Thomas T. Warner; Rong-Shyang Sheu; James F. Bowers; R. Ian Sykes; Gregory C. Dodd; Douglas S. Henn

2002-05-01T23:59:59.000Z

138

Quasi-Dynamic Rating Pilot Projects: Tool Development  

Science Conference Proceedings (OSTI)

Operators must rate power equipment conservatively to avoid damage during occasional periods of poor weather. When load and equipment temperatures are not calculated or monitored, power equipment must be assumed to be at high temperature at the onset of limited-time ratings. Such assumptions often result in underestimating thermal capacity (thermal rating) of power equipment under most actual operating conditions. EPRI's Dynamic Thermal Circuit Rating (DTCR) technology, which encompasses a number of soft...

2003-12-12T23:59:59.000Z

139

Solar assisted heat pump on air collectors: A simulation tool  

Science Conference Proceedings (OSTI)

The heating system of the bioclimatic building of the Greek National Centre for Renewable Energy Sources (CRES) comprises two heating plants: the first one includes an air source heat pump, Solar Air Collectors (SACs) and a heat distribution system (comprising a fan coil unit network); the second one is, mainly, a geothermal heat pump unit to cover the ground floor thermal needs. The SAC configuration as well as the fraction of the building heating load covered by the heating plant are assessed in two operation modes; the direct (hot air from the collectors is supplied directly to the heated space) and the indirect mode (warm air from the SAC or its mixture with ambient air is not supplied directly to the heated space but indirectly into the evaporator of the air source heat pump). The technique of the indirect mode of heating aims at maximizing the efficiency of the SAC, saving electrical power consumed by the compressor of the heat pump, and therefore, at optimizing the coefficient of performance (COP) of the heat pump due to the increased intake of ambient thermal energy by means of the SAC. Results are given for three research objectives: assessment of the heat pump efficiency whether in direct or indirect heating mode; Assessment of the overall heating plant efficiency on a daily or hourly basis; Assessment of the credibility of the suggested simulation model TSAGAIR by comparing its results with the TRNSYS ones. (author)

Karagiorgas, Michalis; Galatis, Kostas; Tsagouri, Manolis [Department of Mechanical Engineering Educators, ASPETE, N. Iraklio, GR 14121 (Greece); Tsoutsos, Theocharis [Environmental Engineering Dept., Technical University of Crete, Technical University Campus, GR 73100, Chania (Greece); Botzios-Valaskakis, Aristotelis [Centre for Renewable Energy Sources (CRES), 19th km Marathon Ave., GR 19001, Pikermi (Greece)

2010-01-15T23:59:59.000Z

140

Modeling and simulation of consumer response to dynamic pricing.  

Science Conference Proceedings (OSTI)

Assessing the impacts of dynamic-pricing under the smart grid concept is becoming extremely important for deciding its full deployment. In this paper, we develop a model that represents the response of consumers to dynamic pricing. In the model, consumers use forecasted day-ahead prices to shift daily energy consumption from hours when the price is expected to be high to hours when the price is expected to be low while maintaining the total energy consumption as unchanged. We integrate the consumer response model into the Electricity Market Complex Adaptive System (EMCAS). EMCAS is an agent-based model that simulates restructured electricity markets. We explore the impacts of dynamic-pricing on price spikes, peak demand, consumer energy bills, power supplier profits, and congestion costs. A simulation of an 11-node test network that includes eight generation companies and five aggregated consumers is performed for a period of 1 month. In addition, we simulate the Korean power system.

Valenzuela, J.; Thimmapuram, P.; Kim, J (Decision and Information Sciences); (Auburn Univ.)

2012-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Building Energy Software Tools Directory: TRANSOL  

NLE Websites -- All DOE Office Websites (Extended Search)

TRANSOL TRANSOL is a tool for the design and optimization of solar thermal systems, based on dynamic simulation (TRNSYS). TRANSOL includes climatic data for all over the world,...

142

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Data Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Bookmark and Share Bookmark and Share Data Resources NREL's Geographic Information System (GIS) team develops technology-specific GIS data maps for a variety of areas, as well as targeted analysis tools that can help determine availability of renewable energy resources. Geographic Information System Data NREL's GIS Team develops technology-specific GIS data maps for a variety of areas, including biomass, geothermal, solar, wind, and renewable hydrogen. The team has made some of our datasets available for download through this Web site. 10km and 40km solar datasets are available for the United States and some international sites. 50m wind datasets are available for specific states, regions and some international sites. 25km wind datasets are available for the United States. 90m offshore wind datasets are available

143

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Webmaster  

NLE Websites -- All DOE Office Websites (Extended Search)

Webmaster Webmaster To contact the Webmaster, please provide your name, e-mail address, and message below. When you are finished, click "Send Message." NOTE: If you enter your e-mail address incorrectly, we will be unable to reply. Your name: Your email address: Your message: Send Message Printable Version NREL GIS Home About NREL GIS Renewable Energy Technical Potential Maps Data Resources Data Visualization & Geospatial Tools GIS Staff Publications Mailing List Contact Us Did you find what you needed? Yes 1 No 0 Thank you for your feedback. Would you like to take a moment to tell us how we can improve this page? Submit We value your feedback. Thanks! We've received your feedback. Something went wrong. Please try again later. NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

144

NREL: Dynamic Maps, GIS Data, and Analysis Tools - Maps  

NLE Websites -- All DOE Office Websites (Extended Search)

Bookmark and Share Bookmark and Share Maps NREL's GIS team develops maps for various renewable resources and for specific projects. As a benefit to the public, a majority of static maps are offered and Google Map (KML/KMZ) files on a tool called MapSearch. Biomass Maps Maps showing the biomass resources available in the United States by county. Feedstock categories include crop residues; forest residues; primary and secondary mill residues; urban wood waste; and methane emissions from manure management, landfills, and domestic wastewater treatment. Federal Energy Management Program The Federal Energy Management Program (FEMP) teamed with Geospatial Analysis staff at NREL to update the analysis for this project and created an interactive FEMP Screening Map application. The previous maps have been

145

Lessons Learned From Dynamic Simulations of Advanced Fuel Cycles  

SciTech Connect

Years of performing dynamic simulations of advanced nuclear fuel cycle options provide insights into how they could work and how one might transition from the current once-through fuel cycle. This paper summarizes those insights from the context of the 2005 objectives and goals of the Advanced Fuel Cycle Initiative (AFCI). Our intent is not to compare options, assess options versus those objectives and goals, nor recommend changes to those objectives and goals. Rather, we organize what we have learned from dynamic simulations in the context of the AFCI objectives for waste management, proliferation resistance, uranium utilization, and economics. Thus, we do not merely describe “lessons learned” from dynamic simulations but attempt to answer the “so what” question by using this context. The analyses have been performed using the Verifiable Fuel Cycle Simulation of Nuclear Fuel Cycle Dynamics (VISION). We observe that the 2005 objectives and goals do not address many of the inherently dynamic discriminators among advanced fuel cycle options and transitions thereof.

Steven J. Piet; Brent W. Dixon; Jacob J. Jacobson; Gretchen E. Matthern; David E. Shropshire

2009-04-01T23:59:59.000Z

146

LINAC BEAM DYNAMICS SIMULATIONS WITH PY-ORBIT  

Science Conference Proceedings (OSTI)

Linac dynamics simulation capabilities of the PyORBIT code are discussed. PyORBIT is an open source code and a further development of the original ORBIT code that was created and used for design, studies, and commissioning of the SNS ring. The PyORBIT code, like the original one, has a two-layer structure. C++ is used to perform time-consuming computations, and the program flow is controlled from a Python language shell. The flexible structure makes it possible to use PyORBIT also for linac dynamics simulations. A benchmark of PyORBIT with Parmila and the XAL Online model is presented.

Shishlo, Andrei P [ORNL

2012-01-01T23:59:59.000Z

147

A fully dynamical simulation of central nuclear collisions  

E-Print Network (OSTI)

We present a fully dynamical simulation of central nuclear collisions around mid-rapidity at LHC energies. Unlike previous treatments, we simulate all phases of the collision, including the equilibration of the system. For the simulation, we use numerical relativity solutions to AdS/CFT for the pre-equilibrium stage, viscous hydrodynamics for the plasma equilibrium stage and kinetic theory for the low density hadronic stage. Our pre-equilibrium stage provides initial conditions for hydrodynamics and our results are insensitive to the AdS/hydro switching time. The resulting light particle spectra reproduce the measurements from the ALICE experiment at all transverse momenta.

van der Schee, Wilke; Pratt, Scott

2013-01-01T23:59:59.000Z

148

Dynamic Simulation of DFIG Wind Turbines on FPGA Boards  

E-Print Network (OSTI)

Dynamic Simulation of DFIG Wind Turbines on FPGA Boards Hao Chen, Student Member, IEEE, Song Sun is a friction coefficient. The wind turbine model is based on the relation between the upstream wind speed V w + 1 where p is the air density; Rw is the wind turbine radius; cp (A, (3) is the performance

Zambreno, Joseph A.

149

Simulation of Dynamic Characteristic for Passive Hydraulic Mount  

Science Conference Proceedings (OSTI)

Dynamic modeling of Passive Hydraulic Engine Mounts (PHEM) is developed with inertia track, decoupler and throttle. Mathematically, the state equations governing vibration isolation behaviors of the PHEMs are presented and solved by means of the lumped ... Keywords: passive hydraulic mount, simulation, test

Zhang Yunxia; Fang Zuhua

2009-08-01T23:59:59.000Z

150

Molecular Dynamics Simulations on High-Performance Reconfigurable Computing Systems  

Science Conference Proceedings (OSTI)

The acceleration of molecular dynamics (MD) simulations using high-performance reconfigurable computing (HPRC) has been much studied. Given the intense competition from multicore and GPUs, there is now a question whether MD on HPRC can be competitive. ... Keywords: FPGA-based coprocessors, application acceleration, bioinformatics, biological sequence alignment, high performance reconfigurable computing

Matt Chiu; Martin C. Herbordt

2010-11-01T23:59:59.000Z

151

DOE/NETL IGCC Dynamic Simulator Research and Training Center  

NLE Websites -- All DOE Office Websites (Extended Search)

NETL IGCC Dynamic Simulator NETL IGCC Dynamic Simulator Research and Training Center 01 Aug 2008 Volume 2: IGCC Process Descriptions DOE/NETL-2008/1324 NETL Collaboratory for Process & Dynamic Systems Research Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,

152

Bitraker Anvil: Binary instrumentation for rapid creation of simulation and workload analysis tools  

E-Print Network (OSTI)

A wide range of ARM developers from architects, to compiler writers, to software developers, need tools to understand, analyze, and simulate program behavior. For developers to achieve high levels of system and program correctness, performance, reliability, and power efficiency these tools must be fast and customizable to the problems at hand. BitRaker Anvil is a tool building framework allowing developers to rapidly build tools to achieve these goals. BitRaker Anvil uses binary instrumentation to modify ARM binaries for the purpose of analyzing program behavior. BitRaker Anvil equips the developer with an easy to use API that allows the user to specify the particular program characteristics to analyze. Using this API, the developer can create custom tools to perform simulation or workload analysis several orders of magnitude faster than using a cycle level simulator. Prior binary instrumentation technology requires that analysis code be merged into the same binary as the code to be analyzed. A key new feature of our binary instrumentation framework is ReHost analysis, which allows an instrumented ARM binary to make calls to analysis code that is written in the native format of the desktop machine. Using this for cross-platform ARM development results in analysis that runs orders of magnitude faster while simultaneously reducing the size of the ARM binary images. 1

Brad Calder; Todd Austin; Don Yang; Timothy Sherwood; Suleyman Sair; David Newquist; Tim Cusac

2004-01-01T23:59:59.000Z

153

A Simulation Tool for Combined Rail-Road Transport in Intermodal Terminals  

E-Print Network (OSTI)

A Simulation Tool for Combined Rail-Road Transport in Intermodal Terminals Andrea E. Rizzoli the current flows of freight. On the other side, the growth of freight transport shows a rapidly increasing by road and rail gates and by a set of platforms. Intermodal terminals are inter-connected by rail

Gambardella, Luca Maria

154

NREL researchers discover ways to increase accuracy in building energy simulations tools to improve predictions of  

E-Print Network (OSTI)

NREL researchers discover ways to increase accuracy in building energy simulations tools to improve calculate heat transfer through building enclosures to verify the benefit of energy efficiency upgrades) analysis to calculate the energy loss/gain through building walls and visualize different heat transfer

155

Development of a Combination Boiler Simulator using General Purpose Simulation Tools”, ISA01-P1063, paper presented at  

E-Print Network (OSTI)

This paper describes the methodology with which a detailed simulation of a typical Combination Boiler (multiple-fuel) was developed for use in training and analysis. The boiler that was simulated is a vintage Riley Traveling Grate Spreader Stoker-fired drum unit that is fired by crushed coal and wood bark. It is controlled by a Digital Control System (DCS) and is installed in a paper-mill powerhouse, which is owned by a major paper-manufacturing corporation. Many of the personnel who have operated this boiler for the last 30 to 40 years are nearing retirement age, and the customer felt it was important to have a tool which could be used to familiarize new personnel with boiler operations, and to provide training for current personnel as they worked their way to Operator status. In addition, it could be used to evaluate system design changes prior to them being implemented on the real system. The customer desired a simulation platform that was “open, ” that is, not dependent on a control vendor or special hardware. It needed to run in real-time to be useful for training, and it was also required that it be on a personal computer platform utilizing the Windows operating system. The simulator was constructed using general-purpose simulation software and graphic user interface (GUI) tools. The simulator system was delivered on a networked three-PC platform, with touch-screens and a special keyboard for emulating the actual DCS keyboard. The resulting simulation includes very detailed mathematical models of the combustion and steam generation processes. The simulator is used to teach startup, shutdown, maneuvering and the proper response to various system upsets. It was also utilized as the platform for testing design changes which significantly modified the over-fire air, coal and bark fuel systems, and a complete revision to the boiler control strategy.

Philip S. Bartells; Joseph S. Gauthier

2001-01-01T23:59:59.000Z

156

Tools  

NLE Websites -- All DOE Office Websites (Extended Search)

Maintenance CalendarOutages is the tool to schedule network maintenance and troubleshooting. I've got network trouble. Help me out trouble@es.net is a quick and easy way to...

157

Particle Swarm Optimization of Ceramic Roller Kiln Temperature Field Uniformity Using Computational Fluid Dynamics Tools  

Science Conference Proceedings (OSTI)

In this paper ceramic roller kiln temperature field uniformity is mainly researched using computational fluid dynamics tools and particle swarm optimization (PSO). In consideration of burning and burning temperature control is key technique of burning ... Keywords: PSO, temperature field uniformity, multiple liner regression, uniform design, ceramic roller kiln design

Wenbi Rao; Peng Li

2009-06-01T23:59:59.000Z

158

Development of Design and Simulation Tool for Hybrid Geothermal Heat Pump  

Open Energy Info (EERE)

Design and Simulation Tool for Hybrid Geothermal Heat Pump Design and Simulation Tool for Hybrid Geothermal Heat Pump System Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Development of Design and Simulation Tool for Hybrid Geothermal Heat Pump System Project Type / Topic 1 Recovery Act - Geothermal Technologies Program: Ground Source Heat Pumps Project Type / Topic 2 Topic Area 2: Data Gathering and Analysis Project Description eQUEST is a widely accepted building and HVAC system energy analysis tool (freeware) that is powered with the latest implementation of the DOE-2.2 program. Due to its user-friendly interface and comprehensive capacity for performing building load calculations and HVAC system simulations, eQUEST has been widely used in whole building performance analysis for various purposes, including LEED certification and optimization of building envelop and/or HVAC system designs. In 2006, as a cooperative effort between CM and JJH (the developer of eQUEST), eQUEST capabilities were expanded to include simulation of conventional GHP systems comprised of water-to-air heat pump units, horizontal or vertical ground loop heat exchangers (GLHE), and lakes or wells. However, to date, eQUEST does not model hybrid systems, such as the combination of a fluid cooler in series with a GLHE. Nor is it capable of simulating water-to-water heat pumps coupled to a horizontal or vertical GLHE. As a result, significant opportunities are being missed, as hybrid and/or water-to-water GHP system applications may prove to be a cost effective solution in many situations.

159

Climate Simulations with an Isentropic Finite Volume Dynamical Core  

SciTech Connect

This paper discusses the impact of changing the vertical coordinate from a hybrid pressure to a hybrid-isentropic coordinate within the finite volume dynamical core of the Community Atmosphere Model (CAM). Results from a 20-year climate simulation using the new model coordinate configuration are compared to control simulations produced by the Eulerian spectral and FV dynamical cores of CAM which both use a pressure-based ({sigma}-p) coordinate. The same physical parameterization package is employed in all three dynamical cores. The isentropic modeling framework significantly alters the simulated climatology and has several desirable features. The revised model produces a better representation of heat transport processes in the atmosphere leading to much improved atmospheric temperatures. We show that the isentropic model is very effective in reducing the long standing cold temperature bias in the upper troposphere and lower stratosphere, a deficiency shared among most climate models. The warmer upper troposphere and stratosphere seen in the isentropic model reduces the global coverage of high clouds which is in better agreement with observations. The isentropic model also shows improvements in the simulated wintertime mean sea-level pressure field in the northern hemisphere.

Chen, Chih-Chieh; Rasch, Philip J.

2012-04-15T23:59:59.000Z

160

Ad Hoc Distributed Dynamic Data-Driven Simulations of Surface Transportation Systems  

Science Conference Proceedings (OSTI)

An ad hoc distributed dynamic data-driven simulation is a collection of autonomous online simulations brought together to model an operational system. They offer the potential of increased accuracy, responsiveness, and robustness compared to centralized ... Keywords: ad hoc distributed simulation, dynamic data-driven application system, microscopic simulation model, online simulation

Michael Hunter; Hoe Kyoung Kim; Wonho Suh; Richard Fujimoto; Jason Sirichoke; Mahesh Palekar

2009-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Prototyping Bio-Nanorobots using Molecular Dynamics Simulation  

E-Print Network (OSTI)

This paper presents a molecular mechanics study using a molecular dynamics software (NAMD) coupled to virtual reality (VR) techniques for intuitive Bio-NanoRobotic prototyping. Using simulated Bio-Nano environments in VR, the operator can design and characterize through physical simulation and 3-D visualization the behavior of Bio-NanoRobotic components and structures. The main novelty of the proposed simulations is based on the characterization of stiffness performances of passive joints-based deca-alanine protein molecule and active joints-based viral protein motor (VPL) in their native environment. Their use as elementary Bio-NanoRobotic components (1 dof platform) are also simulated and the results discussed.

Hamdi, Mustapha; Ferreira, A; Mavroidis, Constantinos

2007-01-01T23:59:59.000Z

162

The molecular dynamics simulation of ion-induced ripple growth  

Science Conference Proceedings (OSTI)

The wavelength-dependence of ion-sputtering induced growth of repetitive nanostructures, such as ripples has been studied by molecular dynamics (MD) simulations in Si. The early stage of the ion erosion driven development of ripples has been simulated on prepatterned Si stripes with a wavy surface. The time evolution of the height function and amplitude of the sinusoidal surface profile has been followed by simulated ion-sputtering. According to Bradley-Harper (BH) theory, we expect correlation between the wavelength of ripples and the stability of them. However, we find that in the small ripple wavelength ({lambda}) regime BH theory fails to reproduce the results obtained by molecular dynamics. We find that at short wavelengths ({lambda}35 nm is stabilized in accordance with the available experimental results. According to the simulations, few hundreds of ion impacts in {lambda} long and few nanometers wide Si ripples are sufficient for reaching saturation in surface growth for for {lambda}>35 nm ripples. In another words, ripples in the long wavelength limit seems to be stable against ion-sputtering. A qualitative comparison of our simulation results with recent experimental data on nanopatterning under irradiation is attempted.

Suele, P. [Research Institute for Technical Physics and Materials Science, Konkoly Thege u. 29-33, 1125 Budapest (Hungary); Heinig, K.-H. [Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden (Germany)

2009-11-28T23:59:59.000Z

163

Adaptive Construction Modelling Within Whole Building Dynamic Simulation  

E-Print Network (OSTI)

............................ vii List of Symbols .......................... ix Chapter 1: Introduction ....................... 1 1.1 The need for building energy simulation ............... 1 1.2 The evolution of building energy simulation tools ............ 2 1.3 The need for accurate building fabric modelling ............ 4 1.4 Objective and outline of the present work ............... 5 Chapter 2: Review of Heat and Moisture Transport within Building Materials ...... 8 2.1 Building energy simulation ................... 8 2.1.1 Heat conduction .................... 8 2.1.2 Mass diffusion .................... 16 2.2 Adaptive gridding ...................... 18 2.3 Thermophysical properties ................... 23 2.4 Combined heat and moisture transport ................ 27 2.4.1 Moisture transport in porous building materials .......... 29 2.4.2 Differential equations for combined heat and moisture transport ..... 33 Chapter 3: Adaptive Building Fabric Gridding ................ 37 3.1 Math...

Abdullatif Nakhi Degree; Abdullatif E. Nakhi; Wife Masoumah

1995-01-01T23:59:59.000Z

164

Simulation and Animation Tools for Analysis of Vehicle Collision: SMAC (Simulation Model of Automobile Collisions) and Carmma (Simulation Animations)  

E-Print Network (OSTI)

source code was written in Tcl/Tk(Tool Command Language).Tcl/Tk is a scripting language used on UNIX platforms tosource code is written in Tcl/Tk. For the UNIX operating

Hongola, Bruce; Chan, Ching-Yao

1999-01-01T23:59:59.000Z

165

Simulating Soil Carbon Dynamics, Erosion and Tillage with EPIC  

NLE Websites -- All DOE Office Websites (Extended Search)

Simulating Soil Carbon Dynamics, Erosion Simulating Soil Carbon Dynamics, Erosion and Tillage with EPIC 1 R. C. Izaurralde (cesar.izaurralde@pnl.gov; 202-646-5227) Joint Global Change Research Institute (JGCRI) Pacific Northwest Nat'l Lab. - Univ. of Maryland 901 D St. S.W., Suite 900 Washington, DC 20024-2115 J. R. Williams (williams@brc.tamus.edu; 254-774-6124) Texas A&M University Blackland Research Center 808 East Blackland Road Temple, TX 76502 W. B. McGill (mcgill@unbc.ca) Faculty of Science and Management University of Northern British Columbia 3333 University Way, Prince George, BC V2N 4Z9 N. J. Rosenberg (nj.rosenberg@pnl.gov; 202-646-5029) Joint Global Change Research Institute (JGCRI) Pacific Northwest Nat'l Lab. - Univ. of Maryland 901 D St. S.W., Suite 900 Washington, DC 20024-2115

166

AVESTAR® - Oxy-Coal Carbon Capture (OCCC) Dynamic Simulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxy-Coal Carbon Capture (OCCC) Dynamic Simulator Oxy-Coal Carbon Capture (OCCC) Dynamic Simulator FutureGen 2.0 is a first-of-its-kind, near-zero emissions coal-fueled power plant using oxy-combustion technology to capture the plant's carbon emissions. To help meet the Nation's ever growing demand for clean energy, the FutureGen Industrial Alliance (Alliance) was formed to test and commercialize advanced coal-based systems fully integrated with carbon capture and geologic storage technologies. In cooperation with the U.S. Department of Energy (DOE), the Alliance and its project partners AirLiquide and Babcock & Wilcox, will upgrade an existing power plant in Meredosia, Illinois with oxy-coal carbon capture (OCCC) technology to capture and permanantly store approximately 1.0 million tonnes of CO2 each year.

167

Simulational nanoengineering: Molecular dynamics implementation of an atomistic Stirling engine  

E-Print Network (OSTI)

A nanoscale-sized Stirling engine with an atomistic working fluid has been modeled using molecular dynamics simulation. The design includes heat exchangers based on thermostats, pistons attached to a flywheel under load, and a regenerator. Key aspects of the behavior, including the time-dependent flows, are described. The model is shown to be capable of stable operation while producing net work at a moderate level of efficiency.

Rapaport, D C

2009-01-01T23:59:59.000Z

168

Dynamic Simulation and Training for IGCC Power Plants  

SciTech Connect

Integrated Gasification Combined Cycle (IGCC) is emerging as the technology of choice for providing clean, low-cost electricity for the next generation of coal-fired power plants and will play a central role in the development of high-efficiency, zero-emissions power plants such as FutureGen. Several major utilities and developers recently announced plans to build IGCC plants and other major utilities are evaluating IGCC’s suitability for base-load capacity additions. This recent surge of attention to IGCC power generation is creating a growing demand for experience with the analysis, operation, and control of commercial-scale IGCC plants. To meet this need, the National Energy Technology Laboratory (NETL) has launched a project to develop a generic, full-scope, IGCC dynamic plant simulator for use in establishing a state-of-the-art simulator training center at West Virginia University’s (WVU) National Research Center for Coal and Energy (NRCCE). The IGCC Dynamic Simulator & Training (DS&T) Center will be established under the auspices of the Collaboratory for Process & Dynamic Systems Modeling (“Collaboratory”) organized between NETL, WVU, the University of Pittsburgh, and Carnegie Mellon University.

Erbes, M.R. (Enginomix, LLC); Zitney, S.E

2006-09-01T23:59:59.000Z

169

A dynamic object-oriented architecture approach to ecosystem modeling and simulation.  

SciTech Connect

Modeling and simulation in support of adaptive ecosystem management can be better accomplished through a dynamic, integrated, and flexible approach that incorporates scientific and technological components into a comprehensive ecosystem-modeling framework. The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) integrates ecological models and decision support techniques, through a geographic information system (GIS)-based framework. The Strategic Environmental Research and Development Program (SERDP) sponsored the development of IDLAMS. Initially built upon a GIS framework, IDLAMS is migrating to an object-oriented (OO) architectural framework. An object-oriented architecture is more flexible and modular. It allows disparate applications and dynamic models to be integrated in a manner that minimizes (or eliminates) the need to rework or recreate the system as new models are added to the suite. In addition, an object-oriented design makes it easier to provide run-time feedback among models, thereby making it a more dynamic tool for exploring and providing insight into the interactions among ecosystem processes. Finally, an object-oriented design encourages the reuse of existing technology because OO-IDLAMS is able to integrate disparate models, databases, or applications executed in their native languages. Reuse is also accomplished through a structured approach to building a consistent and reusable object library. This reusability can substantially reduce the time and effort needed to develop future integrated ecosystem simulations.

Dolph, J. E.; Majerus, K. A.; Sydelko, P. J.; Taxon, T. N.

1999-04-09T23:59:59.000Z

170

Molecular Dynamics Simulations of Temperature Equilibration in Dense Hydrogen  

DOE Green Energy (OSTI)

The temperature equilibration rate in dense hydrogen (for both T{sub i} > T{sub e} and T{sub i} < T{sub e}) has been calculated with large-scale molecular dynamics simulations for temperatures between 10 and 300 eV and densities between 10{sup 20}/cc to 10{sup 24}/cc. Careful attention has been devoted to convergence of the simulations, including the role of semiclassical potentials. We find that for Coulomb logarithms L {approx}> 1, Brown-Preston-Singleton [Brown et al., Phys. Rep. 410, 237 (2005)] with the sub-leading corrections and the fit of Gericke-Murillo-Schlanges [Gericke et al., PRE 65, 036418 (2003)] to the T-matrix evaluation of the collision operator, agrees with the MD data to within the error bars of the simulation. For more strongly-coupled plasmas where L {approx}< 1, our numerical results are consistent with the fit of Gericke-Murillo-Schlanges.

Glosli, J; Graziani, F; More, R; Murillo, M; Streitz, F; Surh, M; Benedict, L; Hau-Riege, S; Langdon, A; London, R

2008-02-14T23:59:59.000Z

171

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten  

E-Print Network (OSTI)

Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten Xue Yang using classical molecular dynamic methods. " Low energy deuterium atoms tend to affix to high environment. The deuterium bombardment of monocrystalline tungsten was modeled by molecular dynamics

Harilal, S. S.

172

Visualization of Folktales on a Map by Coupling Dynamic DEVS Simulation within Google Earth  

E-Print Network (OSTI)

Visualization of Folktales on a Map by Coupling Dynamic DEVS Simulation within Google Earth, Google Earth API, Dynamic variable structures Abstract: This paper deals with dynamic visualization of folktales on a map. The visualization is performed using a coupling of dynamic simulation with the google

Paris-Sud XI, Université de

173

A scalable parallel algorithm for dynamic range-limited n-tuple computation in many-body molecular dynamics simulation  

Science Conference Proceedings (OSTI)

Recent advancements in reactive molecular dynamics (MD) simulations based on many-body interatomic potentials necessitate efficient dynamic n-tuple computation, where a set of atomic n-tuples within a given spatial range is constructed ... Keywords: dynamic range-limited n-tuple computation, molecular dynamics, parallel computing

Manaschai Kunaseth, Rajiv K. Kalia, Aiichiro Nakano, Ken-ichi Nomura, Priya Vashishta

2013-11-01T23:59:59.000Z

174

Development of a carburizing and quenching simulation tool: Numerical simulations of rings and gears  

DOE Green Energy (OSTI)

This paper describes a calculational procedure using the ABAQUS finite element code that simulates a carburizing and quench heat treat cycle for automotive gears. The procedure features a numerically efficient 2-phase constitutive model to represent transformational plasticity effects for the austenite/martensite transformation together with refined finite element meshes to capture the steep gradients in stress and composition near the gear surfaces. The procedure is illustrated on carburizing and quenching of a thick ring, and comparison of model predictions for distortion, phase distribution, and residual stress with experiment is discussed. Sensitivity of predictions to mesh refinement is studied.

Anderson, C.; Goldman, P.; Rangaswamy, P. [Los Alamos National Lab., NM (United States)] [and others

1996-06-24T23:59:59.000Z

175

To appear in: Journal of Mathematics and Computers in Simulation, IMACS/Elsevier Science A Simulation Tool for Combined Rail/Road Transport  

E-Print Network (OSTI)

A Simulation Tool for Combined Rail/Road Transport in Intermodal Terminals Andrea E. Rizzolia,*, Nicoletta and they can support the current flows of freight. On the other hand, the growth of freight transport shows or given as a deterministic input. The simulator can be used to simulate both a single terminal and a rail

Gambardella, Luca Maria

176

Development of directional capabilities to an ultradeep water dynamic kill simulator and simulations runs  

E-Print Network (OSTI)

The world is dependent on the production of oil and gas, and every day the demand increases. Technologies have to keep up with the demand of this resource to keep the world running. Since hydrocarbons are finite and will eventually run out, the increasing demand of oil and gas is the impetus to search for oil in more difficult and challenging areas. One challenging area is offshore in ultradeep water, with water depths greater than 5000 ft. This is the new arena for drilling technology. Unfortunately with greater challenges there are greater risks of losing control and blowing out a well. A dynamic kill simulator was developed in late 2004 to model initial conditions of a blowout in ultradeep water and to calculate the minimum kill rate required to kill a blowing well using the dynamic kill method. The simulator was simple and efficient, but had limitations; only vertical wells could be simulated. To keep up with technology, modifications were made to the simulator to model directional wells. COMASim (Cherokee, Offshore Technology Research Center, Minerals Management Service, Texas A&M Simulator) is the name of the dynamic kill simulator. The new version, COMASim1.0, has the ability to model almost any type of wellbore geometry when provided the measured and vertical depths of the well. Eighteen models with varying wellbore geometry were simulated to examine the effects of wellbore geometry on the minimum kill rate requirement. The main observation was that lower kill rate requirement was needed in wells with larger measured depth. COMASim 1.0 cannot determine whether the inputs provided by the user are practical; COMASim 1.0 can only determine if the inputs are incorrect, inconsistent or cannot be computed. If unreasonable drilling scenarios are input, unreasonable outputs will result. COMASim1.0 adds greater functionality to the previous version while maintaining the original framework and simplicity of calculations and usage.

Meier, Hector Ulysses

2005-08-01T23:59:59.000Z

177

Preliminary analysis of the dynamic heliosphere by MHD simulations  

SciTech Connect

A preliminary analysis of the dynamic heliosphere to estimate the termination shock (TS) distance from the sun around the time when Voyager 1 passed the termination shock at December 16, 2004 is performed by using MHD simulations. For input to this simulation, we use the Voyager 2 solar-wind data. We first find a stationary solution of the 3-D outer heliosphere by assigning a set of LISM parameters as our outer boundary conditions and then the dynamical analysis is performed. The model TS crossing is within 6 months of the observed date. The TS is pushed outward every time a high ram-pressure solar wind pulse arrives. After the end of the high ram-pressure wind, the TS shock shrinks inward. When the last Halloween event passed through the TS at DOY 250, 2004, the TS began to shrink inward very quickly and the TS crossed V1. The highest inward speed of the TS is over 400 km/s. The high ram-pressure solar wind transmitted through the TS becomes a high thermal-pressure plasma in the heliosheath, acting to push the TS inward. This suggests that the position of the TS is determined not only by the steady-state pressure balance condition between the solar wind ram-pressure and the LISM pressure, but by the dynamical ram pressure too. The period when the high ram-pressure solar wind arrives at the TS shock seems to correspond to the period of the TS particle event (Stone et al, 2005, Decker et al., 2005). The TS crossing date will be revised in future simulations using a more appropriate set of parameters for the LISM. This will enable us to undertake a detailed comparison of the simulation results with the TS particle events.

Washimi, H.; Zank, G. P. [Institute of Geophysics and Planetary Physics (IGPP), University of California, Riverside, CA 92521 (United States); Tanaka, T. [Faculty of Science, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan)

2006-09-26T23:59:59.000Z

178

Demonstration of a Computational Fluid Dynamics (CFD) Tool Used for Data  

NLE Websites -- All DOE Office Websites (Extended Search)

Demonstration of a Computational Fluid Dynamics (CFD) Tool Used for Data Demonstration of a Computational Fluid Dynamics (CFD) Tool Used for Data Center Modeling, Thermal Analysis and Operational Management Speaker(s): Saket Karajgikar Date: November 11, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Henry Coles Every Data Center built today is designed with a total capacity in mind, as well as a plan to grow into this final-day load. On a daily basis, Data Center Operations/Management professionals work toward keeping their Data Center as close to this plan as possible by concurrently managing the available power, space, cooling and airflow resources. Unfortunately, lack of communication and information, the pace of change and difficulty in coping with the ever growing power densities of IT equipment can prevent a

179

New Structural-Dynamics Module for Offshore Multimember Substructures within the Wind Turbine Computer-Aided Engineering Tool FAST: Preprint  

DOE Green Energy (OSTI)

FAST, developed by the National Renewable Energy Laboratory (NREL), is a computer-aided engineering (CAE) tool for aero-hydro-servo-elastic analysis of land-based and offshore wind turbines. This paper discusses recent upgrades made to FAST to enable loads simulations of offshore wind turbines with fixed-bottom, multimember support structures (e.g., jackets and tripods, which are commonly used in transitional-depth waters). The main theory and strategies for the implementation of the multimember substructure dynamics module (SubDyn) within the new FAST modularization framework are introduced. SubDyn relies on two main engineering schematizations: 1) a linear frame finite-element beam (LFEB) model and 2) a dynamics system reduction via Craig-Bampton's method. A jacket support structure and an offshore system consisting of a turbine atop a jacket substructure were simulated to test the SubDyn module and to preliminarily assess results against results from a commercial finite-element code.

Song, H.; Damiani, R.; Robertson, A.; Jonkman, J.

2013-08-01T23:59:59.000Z

180

Molecular Dynamics Simulations from SNL's Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS)  

DOE Data Explorer (OSTI)

LAMMPS (http://lammps.sandia.gov/index.html) stands for Large-scale Atomic/Molecular Massively Parallel Simulator and is a code that can be used to model atoms or, as the LAMMPS website says, as a parallel particle simulator at the atomic, meso, or continuum scale. This Sandia-based website provides a long list of animations from large simulations. These were created using different visualization packages to read LAMMPS output, and each one provides the name of the PI and a brief description of the work done or visualization package used. See also the static images produced from simulations at http://lammps.sandia.gov/pictures.html The foundation paper for LAMMPS is: S. Plimpton, Fast Parallel Algorithms for Short-Range Molecular Dynamics, J Comp Phys, 117, 1-19 (1995), but the website also lists other papers describing contributions to LAMMPS over the years.

Plimpton, Steve; Thompson, Aidan; Crozier, Paul

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181

Force spectroscopy of polymer desorption: Theory and Molecular Dynamics simulation  

E-Print Network (OSTI)

Forced detachment of a single polymer chain, strongly-adsorbed on a solid substrate, is investigated by two complementary methods: a coarse-grained analytical dynamical model, based on the Onsager stochastic equation, and Molecular Dynamics (MD) simulations with Langevin thermostat. The suggested approach makes it possible to go beyond the limitations of the conventional Bell-Evans model. We observe a series of characteristic force spikes when the pulling force is measured against the cantilever displacement during detachment at constant velocity $v_c$ (displacement control mode) and find that the average magnitude of this force increases as $v_c$ grows. The probability distributions of the pulling force and the end-monomer distance from the surface at the moment of final detachment are investigated for different adsorption energy $\\epsilon$ and pulling velocity $v_c$. Our extensive MD-simulations validate and support the main theoretical findings. Moreover, the simulation reveals a novel behavior: for a strong-friction and massive cantilever the force spikes pattern is smeared out at large $v_c$. As a challenging task for experimental bio-polymers sequencing in future we suggest the fabrication of stiff, super-light, nanometer-sized AFM probe.

J. Paturej; J. L. A. Dubbeldam; V. G. Rostiashvili; A. Milchev; T. A. Vilgis

2013-10-14T23:59:59.000Z

182

Assessment of Tools and Data for System-Level Dynamic Analyses  

SciTech Connect

The only fuel cycle for which dynamic analyses and assessments are not needed is the null fuel cycle - no nuclear power. For every other concept, dynamic analyses are needed and can influence relative desirability of options. Dynamic analyses show how a fuel cycle might work during transitions from today's partial fuel cycle to something more complete, impact of technology deployments, location of choke points, the key time lags, when benefits can manifest, and how well parts of fuel cycles work together. This report summarizes the readiness of existing Fuel Cycle Technology (FCT) tools and data for conducting dynamic analyses on the range of options. VISION is the primary dynamic analysis tool. Not only does it model mass flows, as do other dynamic system analysis models, but it allows users to explore various potential constraints. The only fuel cycle for which constraints are not important are those in concept advocates PowerPoint presentations; in contrast, comparative analyses of fuel cycles must address what constraints exist and how they could impact performance. The most immediate tool need is extending VISION to the thorium/U233 fuel cycle. Depending on further clarification of waste management strategies in general and for specific fuel cycle candidates, waste management sub-models in VISION may need enhancement, e.g., more on 'co-flows' of non-fuel materials, constraints in waste streams, or automatic classification of waste streams on the basis of user-specified rules. VISION originally had an economic sub-model. The economic calculations were deemed unnecessary in later versions so it was retired. Eventually, the program will need to restore and improve the economics sub-model of VISION to at least the cash flow stage and possibly to incorporating cost constraints and feedbacks. There are multiple sources of data that dynamic analyses can draw on. In this report, 'data' means experimental data, data from more detailed theoretical or empirical calculations on technology performance, and assumptions such as the earliest date a technology can be deployed. The only fuel cycles for which we currently have adequate data are those we are sure we will never build, e.g., a PUREX plant in the U.S. For actual candidates, even for once through LWRs, there remain missing data such as how the fuel cycle would be completed with a geologic repository. The most immediate data needs are probably basic reactor physics data for new concepts and data associated with waste management for anything other than current technology. The readiness of tools and data is fluid and depends on what purposes are envisioned to drive upcoming analyses and further definition of the waste-related characteristics of fuel cycle candidates. Tools and data sets evolve as needs evolve. Thus, much of the document explains that if the FCT program wants a certain type of analysis, then the tools and data needs are as indicated. For example, functions can be treated as either commodities or facilities. Reactors, separation, fuel fabrication, repository are treated as facility types. Other functions such as uranium mining, conversion, enrichment, and waste packaging and non-repository disposal are treated as commodities and therefore not modeled as extensively. In summary, the tools are functional and can answer many fuel cycle questions but some analyses will require that the tools be modified to support those analyses.

Steven J. Piet; Nick R. Soelberg

2011-06-01T23:59:59.000Z

183

Dynamic Simulation and Optimization of Nuclear Hydrogen Production Systems  

DOE Green Energy (OSTI)

This project is part of a research effort to design a hydrogen plant and its interface with a nuclear reactor. This project developed a dynamic modeling, simulation and optimization environment for nuclear hydrogen production systems. A hybrid discrete/continuous model captures both the continuous dynamics of the nuclear plant, the hydrogen plant, and their interface, along with discrete events such as major upsets. This hybrid model makes us of accurate thermodynamic sub-models for the description of phase and reaction equilibria in the thermochemical reactor. Use of the detailed thermodynamic models will allow researchers to examine the process in detail and have confidence in the accurary of the property package they use.

Paul I. Barton; Mujid S. Kaximi; Georgios Bollas; Patricio Ramirez Munoz

2009-07-31T23:59:59.000Z

184

Development of a carburizing and quenching simulation tool: numerical simulations of rings and gears  

DOE Green Energy (OSTI)

The ability to accurately calculate temperatures, stresses and metallurgical transformations in a single calculation or in a sequence of calculations is the key to prediction of distortion, residual stress and phase distribution in quench hardened automotive parts. Successful predictions in turn rely on the adequacy of the input data to the calculational procedure. These data include mechanical and thermal properties of the alloy phases over the range of temperature and strain rates experienced during the heat treat process, the mathematical description of the transformation kinetics, and the accuracy of the heat transfer boundary conditions. In this presentation we describe a calculational procedure using the ABAQUS{sup (1)} finite element code that simulates a carburizing and quench heat treat cycle for automotive gears. The calculational procedure features a numerically efficient 2-phase constitutive model, developed as part of the NCMS-Heat Treatment Distortion Prediction program, to represent transformational plasticity effects for the austenite/martensite Deformation together with refined finite element meshes to capture the steep gradients in stress and composition near the gear surfaces. The calculational procedure is illustrated on carburizing and quenching of a thick ring and comparison of model predictions for distortion, phase distribution, and residual stress with experimental measurements are discussed. Included in this model study is an investigation of the sensitivity of the predictions to mesh refinement.

Anderson, C.; Godlman, P.; Rangaswamy, P. [and others

1996-10-01T23:59:59.000Z

185

Dynamic computer simulation of the Fort St. Vrain steam turbines  

SciTech Connect

A computer simulation is described for the dynamic response of the Fort St. Vrain nuclear reactor regenerative intermediate- and low-pressure steam turbines. The fundamental computer-modeling assumptions for the turbines and feedwater heaters are developed. A turbine heat balance specifying steam and feedwater conditions at a given generator load and the volumes of the feedwater heaters are all that are necessary as descriptive input parameters. Actual plant data for a generator load reduction from 100 to 50% power (which occurred as part of a plant transient on November 9, 1981) are compared with computer-generated predictions, with reasonably good agreement.

Conklin, J.C.

1983-01-01T23:59:59.000Z

186

Processed Splitting Algorithms for Rigid-Body Molecular Dynamics Simulations  

E-Print Network (OSTI)

A new approach for integration of motion in many-body systems of interacting polyatomic molecules is proposed. It is based on splitting time propagation of pseudo-variables in a modified phase space, while the real translational and orientational coordinates are decoded by processing transformations. This allows to overcome the barrier on the order of precision of the integration at a given number of force-torque evaluations per time step. Testing in dynamics of water versus previous methods shows that the obtained algorithms significantly improve the accuracy of the simulations without extra computational costs.

Igor P. Omelyan

2008-05-15T23:59:59.000Z

187

Molecular Dynamics Simulation of Collisions between Hydrogen and Graphite  

E-Print Network (OSTI)

Abstract. Hydrogen adsorption by graphite is examined by classical molecular dynamics simulation using a modified Brenner REBO potential. Such interactions are typical in chemical sputtering experiments, and knowledge of the fundamental behavior of hydrogen and graphene in collisional conditions is essential for modeling the sputtering mechanism. The hydrogen adsorption rate is found to be dependent on the incident hydrogen energy and not on graphene temperature. Rather than destroying the graphene, hydrogen incidence at energies of less than 100 eV can be classified into three regimes of adsorption, reflection and penetration through one or more graphene layers. Incidence at the lowest energies is shown to distort the graphene structure. 1.

unknown authors

2005-01-01T23:59:59.000Z

188

Molecular dynamics simulation of hydrogen diffusion in titanium  

National Nuclear Security Administration (NNSA)

9: Computation Physics 9: Computation Physics Atomistic Simulation of Hydrogen Diffusion in Titanium. Alexandr S. Rokhmanenkov, Alexey Yu. Kuksin, and Vladimir V. Stegailov All-Russia Research Institute of Automatics, Moscow 125412, Russia rohmanenkov@gmail.com Summary Study of the behavior of hydrogen in metals and alloys. The study is based on classical molecular dynamics (MD) and density functional theory (DFT) calculations. Study of the behavior of hydrogen in metals and alloys is of great importance due to the practical uses of hydrogen-metal systems for absorption of nuclear radiation, in neutron sources, for storage of hydrogen, or as catalyzers. This work is devoted to atomistic simulation of hydrogen diffusion in titanium hydrides and the effect of stresses and lattice defects on diffusivity.

189

Structural Modeling and Molecular Dynamics Simulation of the Actin Filament  

DOE Green Energy (OSTI)

Actin is a major structural protein of the eukaryotic cytoskeleton and enables cell motility. Here, we present a model of the actin filament (F-actin) that not only incorporates the global structure of the recently published model by Oda et al. but also conserves internal stereochemistry. A comparison is made using molecular dynamics simulation of the model with other recent F-actin models. A number of structural determents such as the protomer propeller angle, the number of hydrogen bonds, and the structural variation among the protomers are analyzed. The MD comparison is found to reflect the evolution in quality of actin models over the last 6 years. In addition, simulations of the model are carried out in states with both ADP or ATP bound and local hydrogen-bonding differences characterized.

Splettstoesser, Thomas [University of Heidelberg; Holmes, Kenneth [Max Planck Institute, Heidelberg, Germany; Noe, Frank [DFG Research Center Matheon, FU Berlin, Germany; Smith, Jeremy C [ORNL

2011-01-01T23:59:59.000Z

190

Dynamic simulation and performance evaluation of fossil power plants  

Science Conference Proceedings (OSTI)

A dynamic performance model of a standard fossil-fired power plant has been developed. The model contains major components in a plant, including pulverizer, boiler, superheaters, reheaters, economizer, attemperators, pumps, valves, pipings, condenser, turbines, deaerator and low/high pressure feedwater heaters. The EPRI Modular Modeling System (MMS) and Boeing Computer Services' Engineering Analysis System (EASY5) simulation language were used in the analysis. A system control model also developed to simulate the plant control and perform the necessary control functions. The plant model has a general structure and can readily be modified to simulate a specific power plant. To demonstrate the utility of the model, simulation calculations were carried out for a standard coal-fired power plant of the Middle South Services (MSS) during steady state and transient modes of operation. The results were obtained for full load and reduced loads down to 35 percent. In general, good agreement was obtained with the plant heat balance data. 15 refs., 35 figs., 11 tabs.

Hashemi, A.; Lin, C.S.; Munis, A.; Lee, S. (Science Applications International Corp., Hermosa Beach, CA (USA))

1988-12-01T23:59:59.000Z

191

A Dissipative-Particle-Dynamics Model for Simulating Dynamics of Charged Colloid  

E-Print Network (OSTI)

A mesoscopic colloid model is developed in which a spherical colloid is represented by many interacting sites on its surface. The hydrodynamic interactions with thermal fluctuations are taken accounts in full using Dissipative Particle Dynamics, and the electrostatic interactions are simulated using Particle-Particle-Particle Mesh method. This new model is applied to investigate the electrophoretic mobility of a charged colloid under an external electric field, and the influence of salt concentration and colloid charge are systematically studied. The simulation results show good agreement with predictions from the electrokinetic theory.

Jiajia Zhou; Friederike Schmid

2013-11-05T23:59:59.000Z

192

Pseudo-random number generation for Brownian Dynamics and Dissipative Particle Dynamics simulations on GPU devices  

Science Conference Proceedings (OSTI)

Highlights: {yields} Molecular Dynamics codes implemented on GPUs have achieved two-order of magnitude computational accelerations. {yields} Brownian Dynamics and Dissipative Particle Dynamics simulations require a large number of random numbers per time step. {yields} We introduce a method for generating small batches of pseudorandom numbers distributed over many threads of calculations. {yields} With this method, Dissipative Particle Dynamics is implemented on a GPU device without requiring thread-to-thread communication. - Abstract: Brownian Dynamics (BD), also known as Langevin Dynamics, and Dissipative Particle Dynamics (DPD) are implicit solvent methods commonly used in models of soft matter and biomolecular systems. The interaction of the numerous solvent particles with larger particles is coarse-grained as a Langevin thermostat is applied to individual particles or to particle pairs. The Langevin thermostat requires a pseudo-random number generator (PRNG) to generate the stochastic force applied to each particle or pair of neighboring particles during each time step in the integration of Newton's equations of motion. In a Single-Instruction-Multiple-Thread (SIMT) GPU parallel computing environment, small batches of random numbers must be generated over thousands of threads and millions of kernel calls. In this communication we introduce a one-PRNG-per-kernel-call-per-thread scheme, in which a micro-stream of pseudorandom numbers is generated in each thread and kernel call. These high quality, statistically robust micro-streams require no global memory for state storage, are more computationally efficient than other PRNG schemes in memory-bound kernels, and uniquely enable the DPD simulation method without requiring communication between threads.

Phillips, Carolyn L. [Applied Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Anderson, Joshua A. [Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Glotzer, Sharon C., E-mail: sglotzer@umich.edu [Applied Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Material Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-08-10T23:59:59.000Z

193

A Distributed Electrochemistry Modeling Tool for Simulating SOFC Performance and Degradation  

DOE Green Energy (OSTI)

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.

Recknagle, Kurtis P.; Ryan, Emily M.; Khaleel, Mohammad A.

2011-10-13T23:59:59.000Z

194

Combination of job oriented simulation with ecological material flow analysis as integrated analysis tool for business production processes  

Science Conference Proceedings (OSTI)

This paper outlines the application of a special Environmental Management Information System (EMIS) as combination of discrete event simulation with ecological material flow analysis for a selected production process. The software tool serves as decision ...

Philip Joschko; Bernd Page; Volker Wohlgemuth

2009-12-01T23:59:59.000Z

195

Molecular Dynamics Simulations to Compute the Bulk Response of Amorphous PMMA  

E-Print Network (OSTI)

Molecular Dynamics Simulations to Compute the Bulk Response of Amorphous PMMA S.B. Sane* , T. Cagin of molecular dynamics computations and corresponding values of laboratory measurements are compared to assess computational methods has offered the potential for "molecular dynamics" simulations to predict the mechanical

Goddard III, William A.

196

Simulating the Upper Barren Zone and the Ore Zone tests performed with the EMC logging tool  

SciTech Connect

The primary purpose of the Multispectral Nuclear Logging project is to assess the effectiveness of applying nuclear borehole-logging techniques to the Department of Energy`s (DOE) Environmental Restoration (ER) program, adapt the technology to improve these capabilities, and transfer that technology to industry. The purpose of the Monte Carlo simulations using MCNP is to predict the minimum concentration levels for environmental contaminants that could be detected by Multispectral Logging (MSL). The Monte Carlo code used for this type of simulation, MCNP, should be benchmarked against experimental data to show that the user can accurately reproduce the proper gamma-ray spectrum. Experimental data was obtained from Westinghouse-Hanford Company using the Environmental Measurements Corp. (EMC) logging tool in the Upper Barren Zone (UBZ) and Ore Zone (OZ) calibration models at Grand Junction. This paper continues the discussion of benchmarking MCNP using the UBZ and OZ data.

Frankle, S.C.

1994-09-01T23:59:59.000Z

197

Ion dynamics at supercritical quasi-parallel shocks: Hybrid simulations  

Science Conference Proceedings (OSTI)

By separating the incident ions into directly transmitted, downstream thermalized, and diffuse ions, we perform one-dimensional (1D) hybrid simulations to investigate ion dynamics at a supercritical quasi-parallel shock. In the simulations, the angle between the upstream magnetic field and shock nominal direction is {theta}{sub Bn}=30 Degree-Sign , and the Alfven Mach number is M{sub A}{approx}5.5. The shock exhibits a periodic reformation process. The ion reflection occurs at the beginning of the reformation cycle. Part of the reflected ions is trapped between the old and new shock fronts for an extended time period. These particles eventually form superthermal diffuse ions after they escape to the upstream of the new shock front at the end of the reformation cycle. The other reflected ions may return to the shock immediately or be trapped between the old and new shock fronts for a short time period. When the amplitude of the new shock front exceeds that of the old shock front and the reformation cycle is finished, these ions become thermalized ions in the downstream. No noticeable heating can be found in the directly transmitted ions. The relevance of our simulations to the satellite observations is also discussed in the paper.

Su Yanqing; Lu Quanming; Gao Xinliang; Huang Can; Wang Shui [CAS Key Laboratory of Basic Plasma Physics, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei 230026 (China)

2012-09-15T23:59:59.000Z

198

The ArcSDE GIS Dynamic Population Model Tool for Savannah River Site Emergency Response  

Science Conference Proceedings (OSTI)

The Savannah River Site (SRS) is a 310-square-mile Department of Energy site located near Aiken, South Carolina. With a workforce of over 10,000 employees and subcontractors, SRS emergency personnel must be able to respond to an emergency event in a timely and effective manner, in order to ensure the safety and security of the Site. Geographic Information Systems (GIS) provides the technology needed to give managers and emergency personnel the information they need to make quick and effective decisions. In the event of a site evacuation, knowing the number of on-site personnel to evacuate from a given area is an essential piece of information for emergency staff. SRS has developed a GIS Dynamic Population Model Tool to quickly communicate real-time information that summarizes employee populations by facility area and building and then generates dynamic maps that illustrate output statistics.

MCLANE, TRACY; JONES, DWIGHT

2005-10-03T23:59:59.000Z

199

A Dynamic Wind Turbine Simulator of the Wind Turbine Generator System  

Science Conference Proceedings (OSTI)

To study dynamic performances of wind turbine generator system (WTGS), and to determine the control structures in laboratory. The dynamic torque generated by wind turbine (WT) must be simulated. In there paper, a dynamic wind turbine emulator (WTE) is ... Keywords: dynamic wind turbine emulation, wind shear, tower shadow, torque compensation

Lei Lu; Zhen Xie; Xing Zhang; Shuying Yang; Renxian Cao

2012-01-01T23:59:59.000Z

200

Superconducting Circuits for Quantum Simulation of Dynamical Gauge Fields  

E-Print Network (OSTI)

We describe a superconducting-circuit lattice design for the implementation and simulation of dynamical lattice gauge theories. We illustrate our proposal by analyzing a one-dimensional U(1) quantum-link model, where superconducting qubits play the role of matter fields on the lattice sites and the gauge fields are represented by two coupled microwave resonators on each link between neighboring sites. A detailed analysis of a minimal experimental protocol for probing the physics related to string breaking effects shows that despite the presence of decoherence in these systems, distinctive phenomena from condensed-matter and high-energy physics can be visualized with state-of-the-art technology in small superconducting-circuit arrays.

D. Marcos; P. Rabl; E. Rico; P. Zoller

2013-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Video of Simulation of the Dynamics of a Wind-Driven Fire in a ...  

Science Conference Proceedings (OSTI)

Simulation of the Dynamics of a Wind-Driven Fire in a Ranch-Style House – Texas. Wind Driven Fire in Home, Texas, 2009. ...

2013-06-28T23:59:59.000Z

202

Web-based simulation 2: performance prediction of dynamic component substitutions  

Science Conference Proceedings (OSTI)

The Web-based Environment for Systems Engineering (wese) is a web-based modeling and simulation environment in which the level of abstraction of a model can be configured statically (prior to simulation) or dynamically (during ...

Dhananjai M. Rao; Philip A. Wilsey

2002-12-01T23:59:59.000Z

203

Time-domain non-Monte Carlo noise simulation for nonlinear dynamic circuits with arbitrary excitations  

Science Conference Proceedings (OSTI)

A new, time-domain, non-Monte Carlo method for computer simulation of electrical noise in nonlinear dynamic circuits with arbitrary excitations is presented. This time-domain noise simulation ...

Alper Demir; Edward W. Y. Liu; Alberto L. Sangiovanni-Vincentelli

1994-11-01T23:59:59.000Z

204

Dynamic parameterization to simulate DIN export due to gypsy moth defoliation  

Science Conference Proceedings (OSTI)

A module of dynamic parameterization is added into the HSPF watershed software for simulation of dissolved inorganic nitrogen (DIN) export from forest associated with gypsy moth defoliation. It simulates a changing ecosystem following the breakout of ...

Ping Wang; Lewis C. Linker; Keith N. Eshleman

2003-06-01T23:59:59.000Z

205

Consequences of Urban Stability Conditions for Computational Fluid Dynamics Simulations of Urban Dispersion  

Science Conference Proceedings (OSTI)

The validity of omitting stability considerations when simulating transport and dispersion in the urban environment is explored using observations from the Joint Urban 2003 field experiment and computational fluid dynamics simulations of that ...

Julie K. Lundquist; Stevens T. Chan

2007-07-01T23:59:59.000Z

206

Hybrid Ground Source Heat Pump System Simulation Using Visual Modeling Tool For Hvacsim  

E-Print Network (OSTI)

This paper presents a simulation of a hybrid ground source heat pump system, performed using a new graphical user interface for HVACSIM+. Hybrid ground source heat pump systems incorporate both ground loop heat exchangers and supplemental heat rejecters, such as cooling towers, cooling ponds, or pavement heating systems. HVACSIM+ capabilities have recently been extended by the addition of ground loop heat exchanger models, water-to-water and waterto-air heat pump models, pavement heating system models, and heat rejection pond models. New component models are discussed and a hybrid ground source heat pump system with heated pavement as a supplemental cooler is simulated using the visual modeling tool. First, though, an introduction to a new graphical user interface for HVACSIM+ is given. The user interface that originally came with the program could not be characterized as user-friendly. The new graphical interface allows users to develop system models by hooking components together. Provisions for controlling the simulation, setting the component parameters, editing the boundary file, and plotting the output are also included.

M. H. Khan; A. Varanasi; J. D. Spitler; D. E. Fisher; R. D. Delahoussaye

2003-01-01T23:59:59.000Z

207

Surface detection, meshing and analysis during large molecular dynamics simulations  

SciTech Connect

New techniques are presented for the detection and analysis of surfaces and interfaces in atomistic simulations of solids. Atomistic and other particle-based simulations have no inherent notion of a surface, only atomic positions and interactions. The algorithms we introduce here provide an unambiguous means to determine which atoms constitute the surface, and the list of surface atoms and a tessellation (meshing) of the surface are determined simultaneously. The algorithms have been implemented and demonstrated to run automatically (on the fly) in a large-scale parallel molecular dynamics (MD) code on a supercomputer. We demonstrate the validity of the method in three applications in which the surfaces and interfaces evolve: void surfaces in ductile fracture, the surface morphology due to significant plastic deformation of a nanoscale metal plate, and the interfaces (grain boundaries) and void surfaces in a nanoscale polycrystalline system undergoing ductile failure. The technique is found to be quite robust, even when the topology of the surfaces changes as in the case of void coalescence where two surfaces merge into one. It is found to add negligible computational overhead to an MD code, and is much less expensive than other techniques such as the solvent-accessible surface.

Dupuy, L M; Rudd, R E

2005-08-01T23:59:59.000Z

208

Fluidic Catalytic Cracking Power Recovery Dynamic Computer Simulation  

E-Print Network (OSTI)

Fluidic Cat Crackers (FCC) using the catalyst regeneration cycle are candidates for more power efficient operation by the use of high temperature dirty gas expanders. In a previous paper, a computer simulation was described for the steady state operation of the primary mechanical components, specifically the axial compressor and hot gas expander. The present work expands upon the steady state model to add the dynamic characteristics of these elements as well as the effects of the controlling process valves. In many applications the expander will develop more power than the axial compressor can absorb. A power absorbing source, specifically an electrical generator, converts the mechanical excess power into electrical energy. A review of the mechanical equipment and the electrical generator operating modes and controls is needed so that the process designer and operator will know how the system will respond if process upsets were to occur. The program code developed can simulate these elements for specific processes and demonstrate the logic control scheme proposed by the process designer. This information will therefore allow the process operator, process designer and mechanical equipment supplier an understanding of the interplay of the system control elements and define specific operating limits.

Samurin, N. A.

1980-01-01T23:59:59.000Z

209

Enhanced molecular dynamics for simulating porous interphase layers in batteries.  

DOE Green Energy (OSTI)

Understanding charge transport processes at a molecular level using computational techniques is currently hindered by a lack of appropriate models for incorporating anistropic electric fields in molecular dynamics (MD) simulations. An important technological example is ion transport through solid-electrolyte interphase (SEI) layers that form in many common types of batteries. These layers regulate the rate at which electro-chemical reactions occur, affecting power, safety, and reliability. In this work, we develop a model for incorporating electric fields in MD using an atomistic-to-continuum framework. This framework provides the mathematical and algorithmic infrastructure to couple finite element (FE) representations of continuous data with atomic data. In this application, the electric potential is represented on a FE mesh and is calculated from a Poisson equation with source terms determined by the distribution of the atomic charges. Boundary conditions can be imposed naturally using the FE description of the potential, which then propagates to each atom through modified forces. The method is verified using simulations where analytical or theoretical solutions are known. Calculations of salt water solutions in complex domains are performed to understand how ions are attracted to charged surfaces in the presence of electric fields and interfering media.

Zimmerman, Jonathan A.; Wong, Bryan Matthew; Jones, Reese E.; Templeton, Jeremy Alan; Lee, Jonathan (Rice University, Houston, TX)

2009-10-01T23:59:59.000Z

210

HyPro: A Financial Tool for Simulating Hydrogen Infrastructure Development, Final Report  

DOE Green Energy (OSTI)

This report summarizes a multi-year Directed Technologies Inc. (DTI) project to study the build-out of hydrogen production facilities during the transition from gasoline internal combustion engine vehicle to hydrogen fuel cell vehicles. The primary objectives of the project are to develop an enhanced understanding of hydrogen production issues during the transition period (out to 2050) and to develop recommendations for the DOE on areas of further study. These objectives are achieved by conducting economic and scenario analysis to predict how industry would provide the hydrogen production, delivery and dispensing capabilities necessary to satisfy increased hydrogen demand. The primary tool used for the analysis is a custom created MatLab simulation tool entitled HyPro (short for Hydrogen Production). This report describes the calculation methodology used in HyPro, the baseline assumptions, the results of the baseline analysis and several corollary studies. The appendices of this report included a complete listing of model assumptions (capital costs, efficiencies, feedstock prices, delivery distances, etc.) and a step-by-step manual on the specific operation of the HyPro program. This study was made possible with funding from the U.S. Department of Energy (DOE).

Brian D. James, Peter O. Schmidt, Julie Perez

2008-12-01T23:59:59.000Z

211

Molecular Dynamics Simulations of Heat Transfer In Nanoscale Liquid Films  

E-Print Network (OSTI)

Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot properly model thermal interactions at the wall-fluid interface. In order to properly simulate the flow and heat transfer in nano-scale channels, an interactive thermal wall model is developed. Using this model, the Fourier’s law of heat conduction is verified in a 3.24 nm height channel, where linear temperature profiles with constant thermal conductivity is obtained. The thermal conductivity is verified using the predictions of Green-Kubo theory. MD simulations at different wall wettability ( ??f /? ) and crystal bonding stiffness values (K) have shown temperature jumps at the liquid/solid interface, corresponding to the well known Kapitza resistance. Using systematic studies, the thermal resistance length at the interface is characterized as a function of the surface wettability, thermal oscillation frequency, wall temperature and thermal gradient. An empirical model for the thermal resistance length, which could be used as the jump-coefficient of a Navier boundary condition, is developed. Temperature distributions in the nano-channels are predicted using analytical solution of the continuum heat conduction equation subjected to the new temperature jump condition, and validated using the MD results. Momentum and heat transfer in shear driven nanochannel flows are also investigated. Work done by the viscous stresses heats the fluid, which is dissipated through the channel walls, maintained at isothermal conditions. Spatial variations in the fluid density, kinematic viscosity, shear- and energy dissipation rates are presented. The energy dissipation rate is almost a constant for ??f /? < 0.6, which results in parabolic temperature profiles in the domain with temperature jumps due to the Kapitza resistance at the liquid/solid interfaces. Using the energy dissipation rates predicted by MD simulations and the continuum energy equation subjected to the temperature jump boundary conditions developed in this study, the analytical solutions are obtained for the temperature profiles, which agree well with the MD results.

Kim, Bo Hung

2009-05-01T23:59:59.000Z

212

Verification of the Effectiveness of VSOP-2 Phase Referencing with a Newly Developed Simulation Tool, ARIS  

E-Print Network (OSTI)

The next-generation space VLBI mission, VSOP-2, is expected to provide unprecedented spatial resolutions at 8.4, 22, and 43GHz. In this report, phase referencing with VSOP-2 is examined in detail based on a simulation tool called ARIS. The criterion for successful phase referencing was to keep the phase errors below one radian. Simulations with ARIS reveal that phase referencing achieves good performance at 8.4GHz, even under poor tropospheric conditions. At 22 and 43GHz, it is recommended to conduct phase referencing observations under good or typical tropospheric conditions. The satellite is required to have an attitude-switching capability with a one-minute or shorter cycle, and an orbit determination accuracy higher than about 10cm at apogee; the phase referencing calibrators are required to have a signal-to-noise ratio larger than four for a single scan. The probability to find a suitable phase referencing calibrator was estimated by using VLBI surveys. From the viewpoint of calibrator availability, VSOP-2 phase referencing at 8.4GHz is promising. However, the change of finding suitable calibrators at 22 and 43GHz is significantly reduced; it is important to conduct specific investigations for each target at those frequencies.

Yoshiharu Asaki; Hiroshi Sudou; Yusuke Kono; Akihiro Doi; Richard Dodson; Nicolas Pradel; Yasuhiro Murata; Nanako Mochizuki; Philip G. Edwards; Tetsuo Sasao; Edward B. Fomalont

2007-07-04T23:59:59.000Z

213

Physics and Algorithm Enhancements for a Validated MCNP/X Monte Carlo Simulation Tool, Phase VII  

SciTech Connect

Currently the US lacks an end-to-end (i.e., source-to-detector) radiation transport simulation code with predictive capability for the broad range of DHS nuclear material detection applications. For example, gaps in the physics, along with inadequate analysis algorithms, make it difficult for Monte Carlo simulations to provide a comprehensive evaluation, design, and optimization of proposed interrogation systems. With the development and implementation of several key physics and algorithm enhancements, along with needed improvements in evaluated data and benchmark measurements, the MCNP/X Monte Carlo codes will provide designers, operators, and systems analysts with a validated tool for developing state-of-the-art active and passive detection systems. This project is currently in its seventh year (Phase VII). This presentation will review thirty enhancements that have been implemented in MCNPX over the last 3 years and were included in the 2011 release of version 2.7.0. These improvements include 12 physics enhancements, 4 source enhancements, 8 tally enhancements, and 6 other enhancements. Examples and results will be provided for each of these features. The presentation will also discuss the eight enhancements that will be migrated into MCNP6 over the upcoming year.

McKinney, Gregg W [Los Alamos National Laboratory

2012-07-17T23:59:59.000Z

214

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

E-Print Network (OSTI)

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. Keywords: absorption; chiller; modelling; transient; water-lithium bromide; falling film hal-00713904

Recanati, Catherine

215

The implementation of polarizable and flexible models in molecular dynamics simulations  

Science Conference Proceedings (OSTI)

We discuss a new methodology for implementing polarizable and flexible molecular models - the fluctuating charge and intramolecular potential (fCINTRA) method - in Molecular Dynamics (MD) simulations. An example has been provided for ethanol. In these ... Keywords: message passing interface, molecular dynamics simulation, polarizable and flexible model

Shihao Wang; Natalie M. Cann

2009-06-01T23:59:59.000Z

216

Dynamic simulation model for non-supplementary firing triple-pressure heat recovery steam generator  

Science Conference Proceedings (OSTI)

By using the modular modeling method, a real-time dynamic simulation model for the non-supplementary tri-pressure reheat Heat Recovery Steam Generator (HRSG) is developed. On the basis of mass and energy conservation law, the paper discusses the model ... Keywords: HRSG, dynamic model, modular modelling, simulation

Ning Cui; Bing-Shu Wang; Xiang-Yang Gong; Jian-Qiang Gao

2007-10-01T23:59:59.000Z

217

Nanoaggregation and solubility of crude oil asphaltenes from molecular dynamics simulations  

Science Conference Proceedings (OSTI)

The aggregation and solubility of asphaltenes are studied by classical molecular dynamics simulations. Average three-dimensional atomistic models are built on the basis of experimental data for the asphaltenes from a series of crude oil samples. The ... Keywords: Hildebrand, aggregation, asphaltene, forcefield, molecular dynamics, oil, simulation, solubility, solvent

Francesco Frigerio

2009-12-01T23:59:59.000Z

218

Development of a Simplified Simulation Tool for High Performance K-5 Schools in Hot and Humid Climates  

E-Print Network (OSTI)

This paper presents the preliminary results of an effort to develop a simplified simulation-based tool for designing K-5 high performance schools in hot and humid climates. As a first step of the research, a survey to define the dominant school building shape was conducted in an independent school district in Central Texas. This survey used satellite views of the K-5 schools, where each school shape was classified based on the classification defined by Perkins (2001). In addition, more surveys and a literature review was performed to verify input parameters to drive the building size and other building characteristics. Once the simulation tool and the default parameters are developed, this tool is intended to be used to estimate building energy consumption with limited information about the school building. This paper reports on the classification scheme and automatic building shape generator, as well as preliminary results describing calibration of the simulation to a case study K-5 school.

Im, P.; Haberl, J. S.

2008-08-01T23:59:59.000Z

219

Coupling of a multizone airflow simulation program with computational fluid dynamics for indoor environmental analysis  

E-Print Network (OSTI)

Current design of building indoor environment comprises macroscopIC approaches, such as CONT AM multizone airflow analysis tool, and microscopic approaches that apply Computational Fluid Dynamics (CFD). Each has certain ...

Gao, Yang, 1974-

2002-01-01T23:59:59.000Z

220

Dynamic simulation of dual-speed wind turbine generation  

SciTech Connect

Induction generators have been used since the early development of utility-scale wind turbine generation. An induction generator is the generator of choice because of its ruggedness, and low cost. With an induction generator, the operating speed of the wind turbine is limited to a narrow range (almost constant speed). Dual- speed operation can be accomplished by using an induction generator with two different sets of winding configurations or by using two induction generators with two different rated speeds. With single- speed operation, the wind turbine operates at different power coefficients (Cp) as the wind speed varies. The operation at maximum Cp can occur only at a single wind speed. However, if the wind speed varies across a wider range, the operating Cp will vary significantly. Dual-speed operation has the advantage of enabling the wind turbine to operate at near maximum Cp over a wider range of wind-speeds. Thus, annual energy production can be increased. The dual-speed mode may generate less energy than a variable-speed mode; nevertheless, it offers an alternative to capture more energy than single-speed operation. In this paper, dual-speed operation of a wind turbine will be investigated. One type of control algorithm for dual- speed operation is proposed. Results from a dynamic simulation will be presented to show how the control algorithm works and how power, current and torque of the system vary as the wind turbine is exposed to varying wind speeds.

Muljadi, E.; Butterfield, C.P.

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Dynamic simulation solves process control problem in Oman  

Science Conference Proceedings (OSTI)

A dynamic simulation study solved the process control problems for a Saih Rawl, Oman, gas compressor station operated by Petroleum Development of Oman (PDO). PDO encountered persistent compressor failure that caused frequent facility shutdowns, oil production deferment, and gas flaring. It commissioned MSE (Consultants) Ltd., U.K., to find a solution for the problem. Saih Rawl, about 40 km from Qarn Alam, produces oil and associated gas from a large number of low and high-pressure wells. Oil and gas are separated in three separators. The oil is pumped to Qarn Alam for treatment and export. Associated gas is compressed in two parallel trains. Train K-1115 is a 350,000 standard cu m/day, four-stage reciprocating compressor driven by a fixed-speed electric motor. Train K-1120 is a 1 million standard cu m/day, four-stage reciprocating compressor driven by a fixed-speed electric motor. Train K-1120 is a 1 million standard cu m/day, four-stage centrifugal compressor driven by a variable-speed motor. The paper describes tripping and surging problems with the gas compressor and the control simplifications that solved the problem.

NONE

1998-11-16T23:59:59.000Z

222

A Complexity O(1) priority queue for event driven molecular dynamics simulations  

Science Conference Proceedings (OSTI)

We propose and implement a priority queue suitable for use in event driven molecular dynamics simulations. All operations on the queue take on average O(1) time per collision. In comparison, previously studied queues for event driven molecular dynamics ... Keywords: Molecular dynamics, Priority queue

Gerald Paul

2007-02-01T23:59:59.000Z

223

Simulation tool for variably saturated flow with comprehensive geochemical reactions in two- and three-dimensional domains  

Science Conference Proceedings (OSTI)

We present a software tool for simulations of flow and multi-component solute transport in two- and three-dimensional domains in combination with comprehensive intra-phase and inter-phase geochemistry. The software uses IPhreeqc as a reaction engine ... Keywords: COMSOL, Geochemistry, IPhreeqc, PHREEQC, Reaction, Richards' equation, Solute transport, Unsaturated flow

L. Wissmeier; D. A. Barry

2011-02-01T23:59:59.000Z

224

Simulated annealing assisted optimization of fuzzy rules for maximizing tool life in high-speed milling process  

Science Conference Proceedings (OSTI)

In metal cutting industry it is a common practice to search for optimal combination of cutting parameters in order to maximize the tool life for a fixed minimum value of material removal rate (MRR). After the advent of high-speed milling (HSM) process, ... Keywords: HSM, expert system, fuzzy logic, simulated annealing

Asif Iqbal; Ning He; Liang Li; Naeem Ullah Dar

2006-02-01T23:59:59.000Z

225

Dynamic component substitution in web-based simulation  

Science Conference Proceedings (OSTI)

Recent breakthroughs in communication and software engineering has resulted in significant growth of web-based computing. Web-based techniques have been employed for modeling, simulation, and analysis of systems. The models for simulation are usually ...

Dhananjai Madhava Rao; Philip A. Wilsey

2000-12-01T23:59:59.000Z

226

Numerical simulations of granular dynamics II. Particle dynamics in a shaken granular material  

E-Print Network (OSTI)

Surfaces of planets and small bodies of our Solar System are often covered by a layer of granular material that can range from a fine regolith to a gravel-like structure of varying depths. Therefore, the dynamics of granular materials are involved in many events occurring during planetary and small-body evolution thus contributing to their geological properties. We demonstrate that the new adaptation of the parallel N-body hard-sphere code pkdgrav has the capability to model accurately the key features of the collective motion of bidisperse granular materials in a dense regime as a result of shaking. As a stringent test of the numerical code we investigate the complex collective ordering and motion of granular material by direct comparison with laboratory experiments. We demonstrate that, as experimentally observed, the scale of the collective motion increases with increasing small-particle additive concentration. We then extend our investigations to assess how self-gravity and external gravity affect collective motion. In our reduced-gravity simulations both the gravitational conditions and the frequency of the vibrations roughly match the conditions on asteroids subjected to seismic shaking, though real regolith is likely to be much more heterogeneous and less ordered than in our idealised simulations. We also show that collective motion can occur in a granular material under a wide range of inter-particle gravity conditions and in the absence of an external gravitational field. These investigations demonstrate the great interest of being able to simulate conditions that are to relevant planetary science yet unreachable by Earth-based laboratory experiments.

Naomi Murdoch; Patrick Michel; Derek C. Richardson; Kerstin Nordstrom; Christian R. Berardi; Simon F. Green; Wolfgang Losert

2013-06-07T23:59:59.000Z

227

Simulation of Rising Bubbles Dynamics Using the Lattice Boltzmann Method.  

E-Print Network (OSTI)

?? The main purpose of this thesis was to propose and test a new approach that captures the features of single and multiple bubbles dynamics… (more)

Ngachin, Merlin

2011-01-01T23:59:59.000Z

228

A Simulation-based Study of TCP Dynamics  

Science Conference Proceedings (OSTI)

... End Internet Dynamics", Ph.D. Thesis, LBNL-40319, UCB//CSD-97-945, University of California, Berkley. [20] WR Stevens ...

2009-02-03T23:59:59.000Z

229

I12: Quantum Chemical Molecular Dynamics Simulations on ...  

Science Conference Proceedings (OSTI)

To achieve the fabrication with less defects, the dynamic behaviors of ions and radicals with chemical reactions should be clarified. Then, we investigate the ...

230

Performance analysis and optimization of molecular dynamics simulation on Godson-T many-core processor  

Science Conference Proceedings (OSTI)

Molecular dynamics (MD) simulation has broad applications, but its irregular memory-access pattern makes performance optimization a challenge. This paper presents a joint application/architecture study to enhance on-chip parallelism of MD on Godson-T ...

Liu Peng; Aiichiro Nakano; Guangming Tan; Priya Vashishta; Dongrui Fan; Hao Zhang; Rajiv K. Kalia; Fenglong Song

2011-05-01T23:59:59.000Z

231

Qualitative simulation and related approaches for the analysis of dynamic systems  

Science Conference Proceedings (OSTI)

Methods for qualitative simulation allow predictions on the dynamics of a system to be made in the absence of quantitative information, by inferring the range of possible qualitative behaviors compatible with the structure of the system. This article ...

Hidde De Jong

2004-06-01T23:59:59.000Z

232

The Dynamics of an Explosively Developing Cyclone Simulated by a General Circulation Model  

Science Conference Proceedings (OSTI)

The synoptic structure and dynamics of an explosively developing winter extratropical cyclone simulated by NCAR’s CCM2 general circulation model is examined and compared with cyclones that have developed explosively in nature. The primary ...

Karen D. Walthorn; Phillip J. Smith

1998-11-01T23:59:59.000Z

233

A molecular dynamics simulation study of elastic properties of HMX Thomas D. Sewell and Ralph Menikoff  

E-Print Network (OSTI)

. (1989a,b) from a molecular dynamics simulation of the measured structure factor results of Susman et al., and BOLLER,A.,1994, Thermochim. Acta, 238, 227. ZHANG,M., and BOOLCHAND,P.,1994, Science, 266, 1355. 1772

Utah, University of

234

The Effects of Different Climate Input Datasets on Simulated Carbon Dynamics in the Western Arctic  

Science Conference Proceedings (OSTI)

As part of the Western Arctic Linkage Experiment (WALE), simulations of carbon dynamics in the western Arctic (WALE region) were conducted during two recent decades by driving the Terrestrial Ecosystem Model (TEM) with three alternative climate ...

Joy Clein; A. David McGuire; Eugenie S. Euskirchen; Monika Calef

2007-08-01T23:59:59.000Z

235

Transforming molecular biology research through extreme acceleration of AMBER molecular dynamics simulations: sampling for the 99%  

Science Conference Proceedings (OSTI)

This talk will cover recent developments in the acceleration of Molecular Dynamics Simulations using NVIDIA Graphics Processing units with the AMBER software package. In particular it will focus on recent algorithmic improvements aimed at accelerating ...

Ross C. Walker; Levi Pierce; Romelia Salomon

2012-07-01T23:59:59.000Z

236

Simulations of Dynamics and Transport during the September 2002 Antarctic Major Warming  

Science Conference Proceedings (OSTI)

A mechanistic model simulation initialized on 14 September 2002, forced by 100-hPa geopotential heights from Met Office analyses, reproduced the dynamical features of the 2002 Antarctic major warming. The vortex split on 25 September; recovery ...

Gloria L. Manney; Joseph L. Sabutis; Douglas R. Allen; William A. Lahoz; Adam A. Scaife; Cora E. Randall; Steven Pawson; Barbara Naujokat; Richard Swinbank

2005-03-01T23:59:59.000Z

237

Molecular dynamics simulation of hydrogen diffusion in titanium  

National Nuclear Security Administration (NNSA)

of hydrogen-metal systems for absorption of nuclear radiation, in neutron sources, for storage of hydrogen, or as catalyzers. This work is devoted to atomistic simulation of...

238

Computational Fluid Dynamics (CFD) Simulation of Air Dense ...  

Science Conference Proceedings (OSTI)

In current study, the experimental results of coal beneficiation in a cylindrical bed are used to set up and evaluate the results of a CFD simulation software.

239

Office of Fossil EnergyTOPICAL REPORT: DEVELOPMENT OF CFD_BASED SIMULATION TOOLS FOR IN SITU THERMAL PROCESSING OF OIL SHALE/SANDS  

E-Print Network (OSTI)

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. In our research, we are taking the novel approach of developing and applying high performance computing, computational fluid dynamics (CFD)-based simulation tools to a modified in-situ process for production of oil from oil shale. The simulation tools being developed capture the relevant physical processes and data from a large-scale system. The modified in-situ application

Michal Hradisky; Philip J. Smith; Doe Award; No. De-fe

2009-01-01T23:59:59.000Z

240

Simulation of the heat exchangers dynamics in MATLAB&simulink  

Science Conference Proceedings (OSTI)

Heat exchangers that transfer energy from flue gas to steam are important units of thermal power stations. Their inertias are often decisive for the design of the steam temperature control system. In this paper, the analysis and the simulation of the ... Keywords: MATLAB&simulink, S-functions, finite difference method, heat exchangers, partial differential equations, real-time, simulation, superheaters

Pavel Nevriva; Stepan Ozana; Ladislav Vilimec

2009-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

The dynamic simulation of organic farming development scenarios - A case study in Slovenia  

Science Conference Proceedings (OSTI)

In this paper a system dynamics model for organic farming development to support government decision making is presented. The system incorporates relevant variables which affect organic farming development. The user seeks answers to strategic questions ... Keywords: Model, Organic farming, Simulation, System dynamics

Rtomir Rozman, Karmen Paek, Miroljub Kljaji?, Martina Bavec, Jernej Turk, Franc Bavec, Davorin Kofja?, Andrej ŠKraba

2013-08-01T23:59:59.000Z

242

Using system dynamics for simulation and optimization of one coal industry system under fuzzy environment  

Science Conference Proceedings (OSTI)

In this paper, we have developed a model that integrates system dynamics with fuzzy multiple objective programming (SD-FMOP). This model can be used to study the complex interactions in a industry system. In the process of confirming sensitive parameters ... Keywords: Coal industry planning, Fuzzy set theory, Multiple objective programming, Simulation, System dynamics

Jiuping Xu; Xiaofei Li

2011-09-01T23:59:59.000Z

243

ADAPT: abstraction hierarchies to better simulate teamwork under dynamics  

Science Conference Proceedings (OSTI)

In this paper we present a lightweight teamwork implementation by using abstraction hierarchies. The basis of this implementation is ADAPT, which supports Autonomous Dynamic Agent Planning for Teamwork. ADAPT's novelty ...

Meirav Hadad; Avi Rosenfeld

2011-05-01T23:59:59.000Z

244

Dynamical Subgrid-Scale Parameterizations from Direct Numerical Simulations  

Science Conference Proceedings (OSTI)

Dynamical subgrid-scale parameterizations of stochastic backscatter, eddy drain viscosity, and net eddy viscosity have been formulated and calculated for two-dimensional turbulent flows on the sphere based on the statistics of direct numerical ...

Jorgen S. Frederiksen; Steven M. Kepert

2006-11-01T23:59:59.000Z

245

AMIP Simulation with the CAM4 Spectral Element Dynamical Core  

Science Conference Proceedings (OSTI)

The authors evaluate the climate produced by the Community Climate System Model, version 4, running with the new spectral element atmospheric dynamical core option. The spectral element method is configured to use a cubed-sphere grid, providing ...

K. J. Evans; P. H. Lauritzen; S. K. Mishra; R. B. Neale; M. A. Taylor; J. J. Tribbia

2013-02-01T23:59:59.000Z

246

Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations  

SciTech Connect

Defects play an important role on the unique properties of the sp2-bonded materials, such as graphene. The creation and evolution of mono-vacancy, di-vacancy, Stone-Wales (SW) and grain boundaries (GBs) under irradiation in graphene are investigated using density functional theory and time-dependent density functional theory molecular dynamics simulations. It is of great interest to note that the patterns of these defects can be controlled through electron irradiation. The SW defects can be created by electron irradiation with energy of above the displacement threshold energy (Td, {approx}19 eV) and can be healed with an energy (14-18 eV) lower than Td. The transformation between four types of divacancies, V2(5-8-5), V2(555-777), V2(5555-6-7777), and V2(55-77) can be realized through bond rotation induced by electron irradiation. The migrations of divancancies, SW defects, and GBs can also be controlled by electron irradiation. Thus, electron irradiation can serve as an important tool to modify morphology in a controllable manner, and to tailor the physical properties of graphene.

Wang, Zhiguo; Zhou, Yungang; Bang, Junhyeok; Prange, Micah P.; Zhang, Shengbai; Gao, Fei

2012-08-02T23:59:59.000Z

247

Dynamic Simulation of Lightning Attachment to Earthed Overhead Transmission Line Structures  

Science Conference Proceedings (OSTI)

In this paper a novel method is presented to investigate lightning stroke attachment to earthed overhead transmission line structures. This method is based on the dynamic simulation of lightning downward leader movement toward the ground in three dimensions. ... Keywords: charge simulation method, downward leader, lightning, transmission line, upward leader

Mohammad Reza Bank Tavakoli; Behrooz Vahidi

2010-07-01T23:59:59.000Z

248

A simulation-and-regression approach for stochastic dynamic programs with endogenous state variables  

Science Conference Proceedings (OSTI)

We investigate the optimum control of a stochastic system, in the presence of both exogenous (control-independent) stochastic state variables and endogenous (control-dependent) state variables. Our solution approach relies on simulations and regressions ... Keywords: Approximate dynamic programming, Hydropower management, Least-squares Monte Carlo, Simulation and regression, Stochastic control

Michel Denault, Jean-Guy Simonato, Lars Stentoft

2013-11-01T23:59:59.000Z

249

Multilevel Task Partition Algorithm for Parallel Simulation of Power System Dynamics  

Science Conference Proceedings (OSTI)

Nowadays task partition for parallel computing is becoming more and more important. Particular in power system dynamic simulation, it is critical to design an efficient partition algorithm to reduce the communication and balance the computation load ... Keywords: graph partition, parallel simulation, power system, task partition

Wei Xue; Shanxiang Qi

2007-05-01T23:59:59.000Z

250

Time-stepping numerical simulation of switched circuits within the nonsmooth dynamical systems approach  

Science Conference Proceedings (OSTI)

The numerical integration of switching circuits is known to be a tough issue when the number of switches is large, or when sliding modes exist. Then, classical analog simulators may behave poorly, or even fail. In this paper, it is shown on two examples ... Keywords: analog simulation, backward Euler algorithm, complementarity dynamical systems, complementarity problems, multivalued systems, power converters, switching circuits, unilateral state constraints

Vincent Acary; Olivier Bonnefon; Bernard Brogliato

2010-07-01T23:59:59.000Z

251

Agent-based simulation of electricity markets: a survey of tools  

Science Conference Proceedings (OSTI)

Agent-based simulation has been a popular technique in modeling and analyzing electricity markets in recent years. The main objective of this paper is to study existing agent-based simulation packages for electricity markets. We first provide an overview ... Keywords: Adaptation, Agent-based simulation, Artificial life, Electricity market, Swarm intelligence

Zhi Zhou; Wai Kin Chan; Joe H. Chow

2007-12-01T23:59:59.000Z

252

Software support tools for high-speed real-time simulations  

Science Conference Proceedings (OSTI)

Frame times as low as 1-2 microseconds are needed for high-speed real-time (HSRT) simulations of power-electronic systems. To achieve such short frame times it is necessary to use special processing platforms and both digital signal processors (DSPs) ... Keywords: electric circuits, real-time simulation, simulation software

J. J. Zenor; R. E. Crosbie; R. Bednar; D. Word; N. G. Hingorani

2009-07-01T23:59:59.000Z

253

Dynamic simulation of a solar-driven carbon dioxide transcritical power system for small scale combined heat and power production  

SciTech Connect

Carbon dioxide is an environmental benign natural working fluid and has been proposed as a working media for a solar-driven power system. In the current work, the dynamic performance of a small scale solar-driven carbon dioxide power system is analyzed by dynamic simulation tool TRNSYS 16 and Engineering Equation Solver (EES) using co-solving technique. Both daily performance and yearly performance of the proposed system have been simulated. Different system operating parameters, which will influence the system performance, have been discussed. Under the Swedish climatic condition, the maximum daily power production is about 12 kW h and the maximum monthly power production is about 215 kW h with the proposed system working conditions. Besides the power being produced, the system can also produce about 10 times much thermal energy, which can be used for space heating, domestic hot water supply or driving absorption chillers. The simulation results show that the proposed system is a promising and environmental benign alternative for conventional low-grade heat source utilization system. (author)

Chen, Y.; Lundqvist, Per [Div. of Applied Thermodynamics and Refrigeration, Department of Energy Technology, Royal Institute of Technology, SE-100 44 Stockholm (Sweden); Pridasawas, Wimolsiri [King Mongkut's University of Technology Thonburi, Dept. of Chemical Engineering, Bangkok (Thailand)

2010-07-15T23:59:59.000Z

254

Solar Pilot Plant, Phase I. Preliminary design report. Volume II, Book 3. Dynamic simulation model and computer program descriptions. CDRL item 2. [SPP dynamics simulation program  

DOE Green Energy (OSTI)

The mathematical models and computer program comprising the SPP Dynamic Simulation are described. The SPP Dynamic Simulation is a computerized model representing the time-varying performance characteristics of the SPP. The model incorporates all the principal components of the pilot plant. Time-dependent direct normal solar insulation, as corrupted by simulated cloud passages, is transformed into absorbed radiant power by actions of the heliostat field and enclosed receiver cavity. The absorbed power then drives the steam generator model to produce superheated steam for the turbine and/or thermal storage subsystems. The thermal storage subsystem can, in turn, also produce steam for the turbine. The turbine using the steam flow energy produces the mechanical shaft power necessary for the generator to convert it to electrical power. This electrical power is subsequently transmitted to a transmission grid system. Exhaust steam from the turbine is condensed, reheated, deaerated, and pressurized by pumps for return as feedwater to the thermal storage and/or steam generator. A master control/instrumentation system is utilized to coordinate the various plant operations. The master controller reacts to plant operator demands and control settings to effect the desired output response. The SPP Dynamic Simulation Computer program is written in FORTRAN language. Various input options (e.g., insolation values, load demands, initial pressures/temperatures/flows) are permitted. Plant performance may be monitored via computer printout or computer generated plots. The remainder of this document describes the detailed pilot plant dynamic model, the basis for this simulation, and the utilization of this simulation to obtain analytical plant performance results.

None

1977-05-01T23:59:59.000Z

255

Dynamical Influences of Anvil Shading on Simulated Supercell Thunderstorms  

Science Conference Proceedings (OSTI)

Numerical simulations of supercell thunderstorms including parameterized radiative transfer and surface fluxes are performed using the Advanced Regional Prediction System (ARPS) model to investigate how low-level air temperature deficits within ...

Jeffrey Frame; Paul Markowski

2013-08-01T23:59:59.000Z

256

Dynamic Downscaling of Seasonal Simulations over South America  

Science Conference Proceedings (OSTI)

In this paper multiple atmospheric global circulation model (AGCM) integrations at T42 spectral truncation and prescribed sea surface temperature were used to drive regional spectral model (RSM) simulations at 80-km resolution for the austral ...

Vasubandhu Misra; Paul A. Dirmeyer; Ben P. Kirtman

2003-01-01T23:59:59.000Z

257

Author manuscript, published in "11th International Symposium for GIS and Computer Cartography for Coastal Zone Management (CoastGIS 2013), Victoria: Canada (2013)" A dynamic GIS as an efficient tool for ICZM (Bay of Brest, Western France)?  

E-Print Network (OSTI)

This contribution deals with the role of geographical information in participatory research concerning coastal zones and its potential to bridge the gap between research and coastal zone management. The study aims at modeling the interactions between human activities in a maritime basin. A dynamic GIS is used as a tool to facilitate the exchange of points of view and to share knowledge. Geographic information technologies are used at several levels: data collection, GIS analysis, mapping, and simulations. The results show that the GIS-based capture data is well managed by the stakeholders who are interested in contributing to the process of gathering scientific data. The results of a participatory workshop with stakeholders show that the dynamic component of the data adds a real value for management. The possibility to use such a dynamic GIS to discuss and simulate management scenarios is tested, but it needs to be built up gradually.

Françoise Gourmelon; Damien Le Guyader; Guy Fontenelle

2013-01-01T23:59:59.000Z

258

Order parameter prediction from molecular dynamics simulations in proteins  

E-Print Network (OSTI)

A molecular understanding of how protein function is related to protein structure will require an ability to understand large conformational changes between multiple states. Unfortunately these states are often separated by high free energy barriers and within a complex energy landscape. This makes it very difficult to reliably connect, for example by all-atom molecular dynamics calculations, the states, their energies and the pathways between them. A major issue needed to improve sampling on the intermediate states is an order parameter -- a reduced descriptor for the major subset of degrees of freedom -- that can be used to aid sampling for the large conformational change. We present a novel way to combine information from molecular dynamics using non-linear time series and dimensionality reduction, in order to quantitatively determine an order parameter connecting two large-scale conformationally distinct protein states. This new method suggests an implementation for molecular dynamics calculations that ma...

Perilla, Juan R

2011-01-01T23:59:59.000Z

259

AMIP Simulation with the CAM4 Spectral Element Dynamical Core  

SciTech Connect

We evaluate the climate produced by the Community Earth System Model, version 1, running with the new spectral-element atmospheric dynamical core option. The spectral-element method is congured to use a cubed-sphere grid, providing quasi-uniform resolution over the sphere, increased parallel scalability and removing the need for polar filters. It uses a fourth order accurate spatial discretization which locally conserves mass and moist total energy. Using the Atmosphere Model Intercomparison Project protocol, we compare the results from the spectral-element dy- namical core with those produced by the default nite-volume dynamical core and with observations.

Evans, Katherine J [ORNL; Lauritzen, Peter [National Center for Atmospheric Research (NCAR); Mishra, Saroj [National Center for Atmospheric Research (NCAR); Neale, Rich [National Center for Atmospheric Research (NCAR); Taylor, Mark [Sandia National Laboratories (SNL); Tribbia, Joe [National Center for Atmospheric Research (NCAR)

2013-01-01T23:59:59.000Z

260

Dynamic Human Reliability Analysis: Benefits and Challenges of Simulating Human Performance  

Science Conference Proceedings (OSTI)

To date, there has been considerable work on dynamic event trees and other areas related to dynamic probabilistic safety assessment (PSA). The counterpart to these efforts in human reliability analysis (HRA) has centered on the development of specific methods to account for the dynamic nature of human performance. In this paper, the author posits that the key to dynamic HRA is not in the development of specific methods but in the utilization of cognitive modeling and simulation to produce a framework of data that may be used in quantifying the likelihood of human error. This paper provides an overview of simulation approaches to HRA; reviews differences between first, second, and dynamic generation HRA; and outlines potential benefits and challenges of this approach.

R. L. Boring

2007-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Extended Lagrangian quantum molecular dynamics simulations of shock-induced chemistry in hydrocarbons  

SciTech Connect

A set of interatomic potentials for hydrocarbons that are based upon the self-consistent charge transfer tight-binding approximation to density functional theory have been developed and implemented into the quantum molecular dynamics code ''LATTE''. The interatomic potentials exhibit an outstanding level of transferability and have been applied in molecular dynamics simulations of tert-butylacetylene under thermodynamic conditions that correspond to its single-shock Hugoniot. We have achieved precise conservation of the total energy during microcanonical molecular dynamics trajectories under incomplete convergence via the extended Lagrangian Born-Oppenheimer molecular dynamics formalism. In good agreement with the results of a series of flyer-plate impact experiments, our SCC-TB molecular dynamics simulations show that tert-butylactylene molecules polymerize at shock pressures around 6.1 GPa.

Sanville, Edward J [Los Alamos National Laboratory; Bock, Nicolas [Los Alamos National Laboratory; Challacombe, William M [Los Alamos National Laboratory; Cawkwell, Marc J [Los Alamos National Laboratory; Niklasson, Anders M N [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Stephen [Los Alamos National Laboratory; Sewell, Thomas D [UNIV OF MISSOURI

2010-01-01T23:59:59.000Z

262

System dynamics model for simulation of the software inspection process  

Science Conference Proceedings (OSTI)

Repairing a defect in the late phases of software development can be a hundred times more expensive than finding and fixing it during the requirements and design phase. Software inspection is a technique that may be used to aid in the identification ... Keywords: defect detection, software inspection, system dynamics

Jailton Jr. De Sousa Coelho, José Luis Braga, Bernardo Giori Ambrósio

2013-08-01T23:59:59.000Z

263

Numerical aspects in the dynamic simulation of geometrically exact rods  

Science Conference Proceedings (OSTI)

Classical geometrically exact Kirchhoff and Cosserat models are used to study the nonlinear deformation of rods. Extension, bending and torsion of the rod may be represented by the Kirchhoff model. The Cosserat model additionally takes into account shearing ... Keywords: Deformable bodies, Geometrically exact rods, Kirchhoff and Cosserat rods, Method of lines, Multibody dynamics, Partial differential algebraic equations, Time integration

Holger Lang; Martin Arnold

2012-10-01T23:59:59.000Z

264

A model-independent open-source geospatial tool for managing point-based environmental model simulations at multiple spatial locations  

Science Conference Proceedings (OSTI)

A novel geospatial tool box named Geospatial Simulation (GeoSim) has been developed, which can be used to manage point-based model simulations at multiple locations using geospatial data within a geographic information system (GIS). The objectives of ... Keywords: Cotton, GIS, Model, Plug-in, Python, Quantum, Simulation, Spatial, Yield

K. R. Thorp, K. F. Bronson

2013-12-01T23:59:59.000Z

265

System dynamics simulation of the expansion of the Panama Canal  

Science Conference Proceedings (OSTI)

The expansion of the Panama Canal could be the largest project attempted by the Republic of Panama in its 100 years of existence. The objective of this simulation study is to use the Canal Expansion project to develop and demonstrate how more precise ...

Humberto R. Alvarez A.; Dario Solis; Arnoldo R. Cano S.; Serge Sala-Diakanda

2006-12-01T23:59:59.000Z

266

Simulation of Dryline Misovortex Dynamics and Cumulus Formation  

Science Conference Proceedings (OSTI)

A dryline and misocyclones have been simulated in a cloud-resolving model by applying specified initial and time-dependent lateral boundary conditions obtained from analyses of the 22 May 2002 International H2O Project (IHOP_2002) dataset. The ...

Michael S. Buban; Conrad L. Ziegler; Edward R. Mansell; Yvette P. Richardson

2012-11-01T23:59:59.000Z

267

Hybrid Electro-Mechanical Simulation Tool for Wind Turbine Generators: Preprint  

DOE Green Energy (OSTI)

This paper describes the use of MATLAB/Simulink to simulate the electrical and grid-related aspects of a WTG and the FAST aero-elastic wind turbine code to simulate the aerodynamic and mechanical aspects of the WTG. The combination of the two enables studies involving both electrical and mechanical aspects of the WTG.

Singh, M.; Muljadi, E.; Jonkman, J.

2013-05-01T23:59:59.000Z

268

A simulation tool for combined rail/road transport in intermodal terminals  

Science Conference Proceedings (OSTI)

A simulation model of the flow of intermodal terminal units (ITUs) among and within inland intermodal terminals is presented. The intermodal terminals are interconnected by rail corridors. Each terminal serves a user catchment area via a road network. ... Keywords: intermodal terminal simulation, intermodal transport

Andrea E. Rizzoli; Nicoletta Fornara; Luca Maria Gambardella

2002-05-01T23:59:59.000Z

269

Darlington tritium removal facility and station upgrading plant dynamic process simulation  

SciTech Connect

Ontario Power Generation Nuclear (OPGN) has a 4 x 880 MWe CANDU nuclear station at its Darlington Nuclear Div. located in Bowmanville. The station has been operating a Tritium Removal Facility (TRF) and a D{sub 2}O station Upgrading Plant (SUP) since 1989. Both facilities were designed with a Distributed Control System (DCS) and programmable logic controllers (PLC) for process control. This control system was replaced with a DCS only, in 1998. A dynamic plant simulator was developed for the Darlington TRF (DTRF) and the SUP, as part of the computer control system replacement. The simulator was used to test the new software, required to eliminate the PLCs. The simulator is now used for operator training and testing of process control software changes prior to field installation. Dynamic simulation will be essential for the ITER isotope separation system, where the process is more dynamic than the relatively steady-state DTRF process. This paper describes the development and application of the DTRF and SUP dynamic simulator, its benefits, architecture, and the operational experience with the simulator. (authors)

Busigin, A. [NITEK USA, Inc., 6405 NW 77 PL, Parkland, FL 33067 (United States); Williams, G. I. D.; Wong, T. C. W.; Kulczynski, D.; Reid, A. [Ontario Power Generation Nuclear, Box 4000, Bowmanville, ON L1C 3Z8 (Canada)

2008-07-15T23:59:59.000Z

270

Stochastic Simulation of Nonadiabatic Dynamics at Long Time  

E-Print Network (OSTI)

Using a generalized energy-conserving transition probability, it is shown how nonadiabatic calculations, within the Wigner-Heisenberg representation of quantum mechanics, can be reliably extended to far longer times than those allowed by a primitive sampling scheme. Tackling the spin-boson model as a paradigmatic example, substantial numerical evidence is provided that effective integration of the dynamics can be achieved for a wide range of temperatures and friction.

Uken, Daniel A; Petruccione, Francesco

2010-01-01T23:59:59.000Z

271

Stochastic Simulation of Nonadiabatic Dynamics at Long Time  

E-Print Network (OSTI)

Using a generalized energy-conserving transition probability, it is shown how nonadiabatic calculations, within the Wigner-Heisenberg representation of quantum mechanics, can be reliably extended to far longer times than those allowed by a primitive sampling scheme. Tackling the spin-boson model as a paradigmatic example, substantial numerical evidence is provided that effective integration of the dynamics can be achieved for a wide range of temperatures and friction.

Daniel A. Uken; Alessandro Sergi; Francesco Petruccione

2010-03-16T23:59:59.000Z

272

Real-time dynamic simulator for the Topaz II reactor power system  

SciTech Connect

A dynamic simulator of the TOPAZ II reactor system has been developed for the Nuclear Electric Propulsion Space Test Program. The simulator is a self-contained IBM-PC compatible based system that executes at a speed faster than real-time. The simulator combines first-principle modeling and empirical correlations in its algorithm to attain the modeling accuracy and computational through-put that are required for real-time execution. The overall execution time of the simulator for each time step is 15 ms when no data is written to the disk, and 18 ms when nine double precision data points are written to the disk once in every time step. The simulation program has been tested and it is able to handle a step decrease of $8 worth of reactivity. It also provides simulation of fuel, emitter, collector, stainless steel, and ZrH moderator failures. Presented in this paper are the models used in the calculations, a sample simulation session, and a discussion of the performance and limitations of the simulator. The simulator has been found to provide realistic real-time dynamic response of the TOPAZ II reactor system under both normal and causality conditions.

Kwok, K.S.

1994-10-01T23:59:59.000Z

273

The optimizing-simulator: merging simulation and optimization using approximate dynamic programming  

Science Conference Proceedings (OSTI)

There is a wide range of simulation problems that involve making decisions during the simulation, where we would like to make the best decisions possible, taking into account not only what we know when we make the decision, but also the impact of the ...

Warren B. Powell

2007-12-01T23:59:59.000Z

274

Molecular dynamics simulations of the interaction of glucose with imidazole in aqueous solution  

NLE Websites -- All DOE Office Websites (Extended Search)

Molecular dynamics simulations of the interaction of glucose with imidazole in Molecular dynamics simulations of the interaction of glucose with imidazole in aqueous solution Mo Chen, Yannick J. Bomble, Michael E. Himmel, John W. Brady PII: S0008-6215(11)00592-1 DOI: 10.1016/j.carres.2011.12.008 Reference: CAR 6026 To appear in: Carbohydrate Research Received Date: 15 June 2011 Revised Date: 22 November 2011 Accepted Date: 8 December 2011 Please cite this article as: Chen, M., Bomble, Y.J., Himmel, M.E., Brady, J.W., Molecular dynamics simulations of the interaction of glucose with imidazole in aqueous solution, Carbohydrate Research (2011), doi: 10.1016/j.carres. 2011.12.008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and

275

Long-time protein folding dynamics from short-time molecular dynamics simulations  

E-Print Network (OSTI)

histogram analysis method (WHAM) [25, 8] and is shown inexchange simulation by WHAM with corresponding uncertaintiesat 302K, as determined by WHAM, and assigning ini- tial

Chodera, J D; Swope, W C; Pitera, J W; Dill, Ken A

2006-01-01T23:59:59.000Z

276

Femtosecond photoelectron spectroscopy: a new tool for the study of anion dynamics  

SciTech Connect

A new experimental technique for the time-resolved study of anion reactions is presented. Using femtosecond laser pulses, which provide extremely fast ({approx} 100 fs) time resolution, in conjunction with photoelectron spectroscopy, which reveals differences between anion and neutral potential energy surfaces, a complex anion reaction can be followed from its inception through the formation of asymptotic products. Experimental data can be modeled quantitatively using established theoretical approaches, allowing for the refinement of potential energy surfaces as well as dynamical models. After a brief overview, a detailed account of the construction of the experimental apparatus is presented. Documentation of the data acquisition program is contained in the Appendix. The first experimental demonstration of the technique is then presented for I{sub 2}{sup -} photodissociation, modeled using a simulation program which is also detailed in the Appendix. The investigation of I{sub 2}{sup -} photodissociation in several size-selected I{sub 2}{sup -}(Ar){sub n} (n = 6-20) and I{sub 2}{sup -}(CO{sub 2}){sub n} (n = 4-16) clusters forms the heart of the dissertation. In a series of chapters, the numerous effects of solvation on this fundamental bond-breaking reaction are explored, the most notable of which is the recombination of I{sub 2}{sup -} on the ground {tilde X}({sup 2}{Sigma}{sub u}{sup +}) state in sufficiently large clusters. Recombination and trapping of I{sub 2}{sup -} on the excited {tilde A}({sup 2}{Pi}{sub 3/2,g}) state is also observed in both types of clusters. The studies have revealed electronic state transitions, the first step in recombination, on a {approx}500 fs to {approx}10 ps timescale. Accompanying the changes in electronic state is solvent reorganization, which occurs on a similar timescale. Over longer periods ({approx}1 ps to >200 ps), energy is transferred from vibrationally excite d I{sub 2}{sup -} to modes of the solvent, which in turn leads to solvent evaporation. These effects become more important as cluster size increases. In addition, differences in timescale and mechanism are observed between clusters of Ar, which binds to I{sup -} and I{sub 2}{sup -} rather weakly, and CO{sub 2}, whose large quadruple moment allows substantially stronger binding to these anions.

Greenblatt, B.J.

1999-02-01T23:59:59.000Z

277

Human factors simulation tools for the course of action analysis in COIN  

Science Conference Proceedings (OSTI)

Analyzing and modeling of insurgency behavior and decisions is a complex task that can only be conducted by systematic as well as system-view methods. Different approaches like Human Behavior Representation (HBR), Organization Behavior Representation ... Keywords: Human Behavior Representation (HBR), Mass Behavior Representation (MBR), Organization Behavior Representation (OBR), cognitive modeling, decision support tool, mission analysis

Markus Bresinsky; Harald Schaub

2008-06-01T23:59:59.000Z

278

Molecular dynamics simulation of strongly coupled QCD plasmas  

E-Print Network (OSTI)

The properties of a strongly interacting quark plasma are investigated by molecular dynamics method including non-abelian quark-quark potential. Our main goal is to study the thermalization process in this system. We find an interesting resonance-like behaviour: at a characteristic time close to the inverse plasma frequency the quark plasma is heated up substantially via energy transfer from quark potential energy into one particle kinetic energy. Color rotation mechanism enhances the effectivity of this heating process, leading to a very fast thermalization with high temperature.

P. Hartmann; Z. Donko; P. Levai; G. J. Kalman

2006-01-06T23:59:59.000Z

279

Virtual radiation fields -- A virtual environment tool for radiological analysis and simulation  

Science Conference Proceedings (OSTI)

A virtual reality system was developed for computational and graphical modeling and simulation of radiation environments. This system, called Virtual Radiation Fields (VRF), demonstrates the usefulness of radiological analysis in simulation-based design for predicting radiation doses for robotic equipment and personnel working in a radiation environment. The system was developed for use in determining the radiation doses for robotic equipment to be used in tank-waste retrieval operations at the Hanford National Laboratory. As a reference case, specific application is made to simulate cleanup operations for Hanford tank C-106. A three-dimensional model representation of the tank and its predicted radiation levels are presented and analyzed. Tank cleanup operations were simulated to understand how radiation levels change during the cleanup phase and to predict cumulative radiation doses to robotic equipment to aid in the development of maintenance and replacement schedules.

Knight, T.W.; Dalton, G.R.; Tulenko, J.S. [Univ. of Florida, Gainesville, FL (United States). Dept. of Nuclear Engineering Sciences

1997-02-01T23:59:59.000Z

280

Prism: A Multi-view Visualization Tool for Multi-physics Simulation  

Science Conference Proceedings (OSTI)

Complex simulations (in particular, those involving multiple coupled physics) cannot be understood solely using geometry- based visualizations. Such visualizations are necessary in interpretingresults and gaining insights into kinematics, however they ...

David H. Rogers; Christopher J. Garasi

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Design studies for the transmission simulator method of experimental dynamic substructuring.  

SciTech Connect

In recent years, a successful method for generating experimental dynamic substructures has been developed using an instrumented fixture, the transmission simulator. The transmission simulator method solves many of the problems associated with experimental substructuring. These solutions effectively address: (1) rotation and moment estimation at connection points; (2) providing substructure Ritz vectors that adequately span the connection motion space; and (3) adequately addressing multiple and continuous attachment locations. However, the transmission simulator method may fail if the transmission simulator is poorly designed. Four areas of the design addressed here are: (1) designating response sensor locations; (2) designating force input locations; (3) physical design of the transmission simulator; and (4) modal test design. In addition to the transmission simulator design investigations, a review of the theory with an example problem is presented.

Mayes, Randall Lee; Arviso, Michael

2010-05-01T23:59:59.000Z

282

Molecular dynamics simulation of high strain-rate void nucleation and growth in copper  

Science Conference Proceedings (OSTI)

Isotropic tension is simulated in nanoscale polycrystalline copper with 10 nm grain size using large-scale molecular dynamics. The nanocrystalline copper is fabricated on the computer by growing randomly oriented grains from seed sites in simulations cell. Constant volume strain rates of 10-8 to 10-10 are considered for systems ranging from 10-5 to 10-6 atoms using EAM interatomic potential for copper. The spacing between voids for room temperature single crystal simulations is found to scale approximately as l{approximately}0. 005 Cs/gamma, where Cs is the sound speed and gamma is the strain rate. Below strain rates of about 10-9, only one void is observed to nucleate and grow in the 10 nm polycrystalline simulation cell. The growth of small voids is simulated by cutting a void out of the simulation cell and repeating the isotropic expansion.

Belak, J.

1997-07-01T23:59:59.000Z

283

Low Wind Speed Technology Phase II: Offshore Floating Wind Turbine Concepts: Fully Coupled Dynamic Response Simulations; Massachusetts Institute of Technology  

SciTech Connect

This fact sheet describes a subcontract with Massachusetts Institute of Technology to study dynamic response simulations to evaluate floating platform concepts for offshore wind turbines.

2006-03-01T23:59:59.000Z

284

Langevin dynamics simulations of biomolecules on graphics processors  

E-Print Network (OSTI)

Due to the very long timescales involved (us-s), theoretical modeling of fundamental biological processes including folding, misfolding, and mechanical unraveling of biomolecules, under physiologically relevant conditions, is challenging even for distributed computing systems. Graphics Processing Units (GPUs) are emerging as an alternative programming platform to the more traditional CPUs as they provide high raw computational power that can be utilized in a wide range of scientific applications. Using a coarse-grained Self Organized Polymer (SOP) model, we have developed and tested the GPU-based implementation of Langevin simulations for proteins (SOP-GPU program). Simultaneous calculation of forces for all particles is implemented using either the particle based or the interacting pair based parallelization, which leads to a ~30-fold acceleration compared to an optimized CPU version of the program. We assess the computational performance of an end-to-end application of the SOP-GPU program, where all steps of the algorithm are running on the GPU, by profiling the associated simulation time and memory usage for a number of small proteins, long protein fibers, and large-size protein assemblies. The SOP-GPU package can now be used in the theoretical exploration of the mechanical properties of large-size protein systems to generate the force-extension and force-indentation profiles under the experimental conditions of force application, and to relate the results of single-molecule experiments in vitro and in silico.

A. Zhmurov; R. I. Dima; Y. Kholodov; V. Barsegov

2010-03-04T23:59:59.000Z

285

Visualizations and Simulations from the Center for Simulation of Dynamic Response of Materials (ASC/ASAP)  

DOE Data Explorer (OSTI)

The ASC/ASAP Gallery provides access to visualizations in the areas of materials, fluids, solids, and those related to the VTF. A section of tools and resources is available, as well as the full text of a long list of graphics-rich publications (see http://csdrm.caltech.edu/publications/index.html)

286

LSRM - a tool for logic simulation of RISC-based microprocessor  

E-Print Network (OSTI)

Due to their high performance, Reduced Instruction Set Computer (RISC) based microprocessors have been widely used in computing systems as well as embedded control and communication systems. The first and the most important step in designing a RISC microprocessor is to define the instruction set and its corresponding architecture. It will be inconvenient in terms of time and cost to verify an instruction set and its architecture through complete hardware realization. Therefore, a logic simulator for RISC microprocessor is highly desirable. This thesis studies the logic simulation of RISC microprocessors based on behavioral modeling approach. Many behavioral models for the components of RISC microprocessors, like ALU, multiplexer, memory, control unit, are proposed. A prototype, called LSRM (a Logic Simulator for RISC-based Microprocessor), is also designed and implemented in SUN/UNIX environment. LSRM consists of a graphical user interface and a simulator. The user interface is built on the X-window/Motif system while the simulator is implemented in C, Verilog and PLI. The system model adopted in this research is based on the DLX machine. However, substantial extension is made in order to satisfy as many applications as possible.

Jiang, Xiaohua

1993-01-01T23:59:59.000Z

287

NREL: Dynamic Maps, GIS Data, and Analysis Tools - MapSearch  

NLE Websites -- All DOE Office Websites (Extended Search)

Bookmark and Share Bookmark and Share MapSearch MapSearch Logo is a computer monitor with a magnifying glass suspended in the air before it. Use our MapSearch to easily search our collection of maps created by the Geographic Information System (GIS) team. Please use the search box and the filters on the left and right of the screen to limit results. Notice: The current tool works best in Firefox and may result in errors if opened using Microsoft Internet Explorer. June 2013 - The NREL GIS team has released a new beta version of the Mapsearch tool. This new beta version should eliminate some of the browser issues experienced with the current tool. The beta version is designed to work with NREL's OpenEI so users will have one site to search and view NREL created maps. If you have any feeback or comments on this new beta site, contact the Webmaster. While testing is done on this new beta version, the current MapSearch tool is still available. The following instructions apply to the current tool. launch

288

The FireBGCv2 Landscape Fire Succession Model: A Research Simulation Platform for Exploring Fire and Vegetation Dynamics  

E-Print Network (OSTI)

Research Station. 137 p. Fire management faces important emergent issues in the coming years such as climate change, fire exclusion impacts, and wildland-urban development, so new, innovative means are needed to address these challenges. Field studies, while preferable and reliable, will be problematic because of the large time and space scales involved. Therefore, landscape simulation modeling will have more of a role in wildland fire management as field studies become untenable. This report details the design and algorithms of a complex, spatially explicit landscape fire and vegetation model called FireBGCv2. FireBGCv2 is a C++ computer program that incorporates several types of stand dynamics models into a landscape simulation platform. FireBGCv2 is intended as a research tool. Descriptions of FireBGCv2 code, sample input files, and sample output are included in this report, but this report is not intended as a user’s manual because the inherent complexity and wide scope of FireBGCv2 makes it unwieldy and difficult to use without extensive training. The primary purpose of this report is to document FireBGCv2 in adequate detail to interpret simulation results.

United States; Forest Service; Robert E. Keane; Rachel A. Loehman; Lisa M. Holsinger

2011-01-01T23:59:59.000Z

289

Development and application of chemical tools for investigating dynamic processes in cell migration  

E-Print Network (OSTI)

Cell migration is a dynamic process essential for many fundamental physiological functions, including wound repair and the immune response. Migration relies on precisely orchestrated events that are regulated in a spatially ...

Goguen, Brenda Nicole

2011-01-01T23:59:59.000Z

290

Simulated Annealing: A Tool for Data Assimilation into an Almost Steady Model State  

Science Conference Proceedings (OSTI)

A new method is used to calculate a steady-state best fit of a given strongly nonlinear time-dependent model to observed data. The proposed technique has a statistical nature and is known as simulated annealing. It is described in detail and two ...

J. Kruger

1993-04-01T23:59:59.000Z

291

Simulations and virtual reality tools in technology learning: results from two case studies  

Science Conference Proceedings (OSTI)

We present the results of two design-based action research case studies. These case studies sought to develop pedagogical models and computer applications for teaching, studying and learning in technology education. The first pedagogical model entitled ... Keywords: learning environment, pedagogical models, simulations, virtual reality

Miika Lehtonen; Tom Page; Gisli Thorsteinsson; Lence Miloseva

2007-03-01T23:59:59.000Z

292

Use of Passive Tracers as a Diagnostic Tool in Coupled Model Simulations—Northern Hemisphere  

Science Conference Proceedings (OSTI)

This study focuses on the uptake of a passive idealized tracer in the Northern Hemisphere oceans from two coupled ocean–atmosphere simulations: a standard horizontal diffusion case and the second case including the Gent and McWilliams (GM) eddy ...

Siobhan P. O'Farrell

2002-03-01T23:59:59.000Z

293

Simulation studies of ion dynamic effects on dense plasma line shapes  

DOE Green Energy (OSTI)

Computer simulations have been widely used in studying dense plasma properties including the local field properties important in spectral line broadening calculations. We will review here a more recent use of simulation, possibly less familiar to this audience, where the time dependent ionic microfield generated by computer simulation of a plasma is used directly as a time dependent external potential for the evolution of the electronic structure of an ion. This permits calculation of the dipole correlation function and thus line shapes with the inclusion of ion dynamic effects. 12 refs., 7 figs.

Pollock, E.L.

1986-12-01T23:59:59.000Z

294

Molecular dynamics simulation of UO2 nanocrystals melting  

E-Print Network (OSTI)

In this article we study melting of uranium dioxide (UO2) nanocrystals (NC) isolated in vacuum (i.e. non-periodic boundary conditions) using molecular dynamics (MD) in the approximation of pair potentials and rigid ions. We calculate the size dependence of the temperature and heat of melting, the density jump for crystals of cubic shape and volumes up to 1000 nm^3 (50000 particles). Linear and parabolic extrapolations of these dependences to macroscopic (infinite) size are considered, the parabolic is found to be better suited for the analysis of data on the temperature and the heat of melting. The closest to the modern experimental data estimates of the melting temperature of macrocrystals are obtained using the interaction potentials Goel-08 (2969K), Yakub-09 (3105K) and MOX-07 (3291K). The density jump at melting is well reproduced by Yakub-09 (8.66%) and MOX-07 (7.97%). The heat of fusion for all sets of the potentials considered is found to be underestimated by 50-75%, possibly because of the excluded he...

Boyarchenkov, A S; Nekrasov, K A; Kupryazhkin, A Ya

2011-01-01T23:59:59.000Z

295

Validating simulation tools for vehicle system studies using advanced control and testing procedure.  

DOE Green Energy (OSTI)

Hybrid electric vehicles (HEVs) offer the potential to increase propulsion system efficiency and decrease pollutant emissions relative to conventional vehicles. The US Department of Energy (DOE) and the auto industry are developing HEV technology as part of the Partnership for a New Generation of Vehicles (PNGV) program. Argonne National Laboratory (ANL) supports the DOE in this program by contributing to technical target setting and evaluating new technologies in a vehicle systems context. In this role, ANL has developed a unique set of interrelated tools and facilities to analyze, develop, and validate components and propulsion systems in a vehicle environment.

Pasquier, M.; Duoba, M.; Rousseau, A.

2001-09-12T23:59:59.000Z

296

Dynamic Network Forecasting using SimGrid Simulations Matthieu Imbert and Eddy Caron  

E-Print Network (OSTI)

exists. Currently, the most widely-used approach for data management for distributed grid computation capacities, the network equipment capacities (line-cards or back-plane capacity), the interactions bothDynamic Network Forecasting using SimGrid Simulations Matthieu Imbert and Eddy Caron Université de

297

DYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION  

E-Print Network (OSTI)

-tracing study of the heat flux distribution inside the steam receiver is used to spatially refine the modelDYNAMIC SIMULATION OF MONO-TUBE CAVITY RECEIVERS FOR DIRECT STEAM GENERATION José Zapata 1 , John dish has been in operation since 2010 with a mono-tube steam cavity receiver, the SG4 system

298

Simulant-material experimental investigation of flow dynamics in the CRBR Upper-Core Structure  

Science Conference Proceedings (OSTI)

The results of a simulant-material experimental investigation of flow dynamics in the Clinch River Breeder Reactor (CRBR) Upper Core Structure are described. The methodology used to design the experimental apparatus and select test conditions is detailed. Numerous comparisons between experimental data and SIMMER-II Code calculations are presented with both advantages and limitations of the SIMMER modeling features identified.

Wilhelm, D.; Starkovich, V.S.; Chapyak, E.J.

1982-09-01T23:59:59.000Z

299

A simulated annealing approach with probability matrix for semiconductor dynamic scheduling problem  

Science Conference Proceedings (OSTI)

The dynamic scheduling problem of semiconductor burn-in operations is studied in this paper. The burn-in oven is a batch-processing machine and the size of each job is independent of the oven's capacity. The processing time for each batch is represented ... Keywords: Deadlines, Heuristic, Simulated annealing, Total weighted completion time

Fuh-Der Chou; Hui-Mei Wang; Pei-Chann Chang

2008-11-01T23:59:59.000Z

300

Dynamic Modeling and Simulation of Hybrid Power Systems Based on Renewable Energy  

Science Conference Proceedings (OSTI)

This paper describes dynamic modeling and simulation results of a renewable energy based hybrid power system. The paper focuses on the combination of solar cell (SC), wind turbine (WT), fuel cell (FC) and ultra-capacitor (UC) systems for power generation. ... Keywords: fuel cell, hybrid power system, renewable energy, solar cell, ultra-capacitor, wind turbine

Teng-Fa Tsao; Po-Hung Chen; Hung-Cheng Chen

2009-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Research article: Fine grained sampling of residue characteristics using molecular dynamics simulation  

Science Conference Proceedings (OSTI)

In a fine-grained computational analysis of protein structure, we investigated the relationships between a residue's backbone conformations and its side-chain packing as well as conformations. To produce continuous distributions in high resolution, we ... Keywords: Backbone conformation, Dynameome, Molecular dynamics simulation, Ramachandran plot, Residue volume, Rotamer, Side-chain packing

Hyun Joo; Xiaotao Qu; Rosemarie Swanson; C. Michael McCallum; Jerry Tsai

2010-06-01T23:59:59.000Z

302

A Micro-Grid Simulator Tool (SGridSim) using Effective Node-to-Node Complex Impedance (EN2NCI) Models  

SciTech Connect

This paper presents a micro-grid simulator tool useful for implementing and testing multi-agent controllers (SGridSim). As a common engineering practice it is important to have a tool that simplifies the modeling of the salient features of a desired system. In electric micro-grids, these salient features are the voltage and power distributions within the micro-grid. Current simplified electric power grid simulator tools such as PowerWorld, PowerSim, Gridlab, etc, model only the power distribution features of a desired micro-grid. Other power grid simulators such as Simulink, Modelica, etc, use detailed modeling to accommodate the voltage distribution features. This paper presents a SGridSim micro-grid simulator tool that simplifies the modeling of both the voltage and power distribution features in a desired micro-grid. The SGridSim tool accomplishes this simplified modeling by using Effective Node-to-Node Complex Impedance (EN2NCI) models of components that typically make-up a micro-grid. The term EN2NCI models means that the impedance based components of a micro-grid are modeled as single impedances tied between their respective voltage nodes on the micro-grid. Hence the benefit of the presented SGridSim tool are 1) simulation of a micro-grid is performed strictly in the complex-domain; 2) faster simulation of a micro-grid by avoiding the simulation of detailed transients. An example micro-grid model was built using the SGridSim tool and tested to simulate both the voltage and power distribution features with a total absolute relative error of less than 6%.

Udhay Ravishankar; Milos manic

2013-08-01T23:59:59.000Z

303

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

DSM, RES-E, RES-CHP, district heating, bio- fuels, solarcorresponding E.g. missing district heating grid, in urbanHeating plus DHW) dh district heating connection is in

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

304

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

DHW (including solar thermal) Cooling DSM District heatingDSM, heating, cooling, DHW, solar thermal) an option 3technology for heating, cooling, DHW, solar thermal systems.

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

305

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

Schemes for sustainable energy systems”. InternationalPaths to promote Sustainable Energy Systems - The dynamicmoney - for promoting sustainable energy systems - be spent

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

306

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

energy in particular of fossil energy is not very popular (Moderate rise of fossil energy prices by approximately 1%assumed moderate energy price increase of fossil fuels will

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

307

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

promotion schemes, energy prices and strategies can beModerate rise of fossil energy prices by approximately 1%a large part of the energy price paid for district heating

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

308

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

of wood storage for wood heating systems, etc. E.g. comfort,gas district heating oil electricity wood chip s Figure 4.2:district heating. Wood LPG District heating Coal, coke Oil

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

309

Policy Strategies and Paths to promote Sustainable Energy Systems - The dynamic Invert Simulation Tool  

E-Print Network (OSTI)

of DSM subsidy (building insulation and window replacement)building stock is distinguished by a high insulation qualityconcerning buildings. Increasing this subsidy for insulation

Stadler, Michael; Kranzl, Lukas; Huber, Claus; Haas, Reinhard; Tsioliaridou, Elena

2006-01-01T23:59:59.000Z

310

Chaos and dynamical trends in barred galaxies: bridging the gap between N-body simulations and time-dependent analytical models  

E-Print Network (OSTI)

Self-consistent N-body simulations are an efficient tool to study galactic dynamics. However, it can be challenging to use them for the detailed study of individual trajectories (or ensembles of trajectories). Such orbital studies are important to shed light on global phase space properties, which are the underlying cause of observed structures. The potentials needed to describe self-consistent models are in this case time-dependent. For this reason, we aim to investigate the different dynamical properties (such as regular and chaotic motion) of a non-autonomous galactic system, whose time-dependent potential adequately mimics certain realistic trends arising from N-body barred galaxy simulations. We construct a fully time-dependent analytical model, which manages to capture and reproduce several features of an N-body simulation. We model the gravitational potentials of three components (disc, bar and dark matter halo), whose time-dependent parameters are derived from an N-body simulation. We start by studying the dynamical stability of its reduced time-independent 2-degrees of freedom model by charting the different islands of stability associated with certain orbital morphologies and detecting the chaotic and regular regions. We then turn our interest to the full 3-degrees of freedom time-dependent case, where we show a few representative trajectories which experience different typical dynamical behaviours, i.e., an interplay between regular and chaotic motion for different epochs. Finally, we focus on the study of the underlying global dynamical transitions of the time-dependent system in terms of estimating the relative total fraction of (un)stable motion of an ensemble of initial conditions taken from the simulation and evolved with the time-dependent potential. We find that, for such an ensemble, the fraction of regular motion increases with time.

T. Manos; Rubens E. G. Machado

2013-11-14T23:59:59.000Z

311

Particle dynamics in two-dimensional random energy landscapes - experiments and simulations  

E-Print Network (OSTI)

The dynamics of individual colloidal particles in random potential energy landscapes were investigated experimentally and by Monte Carlo simulations. The value of the potential at each point in the two-dimensional energy landscape follows a Gaussian distribution. The width of the distribution, and hence the degree of roughness of the energy landscape, was varied and its effect on the particle dynamics studied. This situation represents an example of Brownian dynamics in the presence of disorder. In the experiments, the energy landscapes were generated optically using a holographic set-up with a spatial light modulator, and the particle trajectories were followed by video microscopy. The dynamics are characterized using, e.g., the time-dependent diffusion coefficient, the mean squared displacement, the van Hove function and the non-Gaussian parameter. In both, experiments and simulations, the dynamics are initially diffusive, show an extended sub-diffusive regime at intermediate times before diffusive motion is recovered at very long times. The dependence of the long-time diffusion coefficient on the width of the Gaussian distribution agrees with theoretical predictions. Compared to the dynamics in a one-dimensional potential energy landscape, the localization at intermediate times is weaker and the diffusive regime at long times reached earlier, which is due to the possibility to avoid local maxima in two-dimensional energy landscapes.

Florian Evers; Christoph Zunke; Richard D. L. Hanes; Joerg Bewerunge; Imad Ladadwa; Andreas Heuer; Stefan U. Egelhaaf

2013-02-13T23:59:59.000Z

312

Numerical Simulation of Thunderstorm Outflow Dynamics. Part I: Outflow Sensitivity Experiments and Turbulence Dynamics  

Science Conference Proceedings (OSTI)

In this first paper of a two-part series, a two-dimensional numerical model is developed and used to investigate the dynamics of thunderstorm outflows. By focusing only on the outflow and using essentially inviscid equations and high spatial ...

Kelvin K. Droegemeier; Robert B. Wilhelmson

1987-04-01T23:59:59.000Z

313

A molecular dynamics simulation of the melting points and glass transition temperatures of myo-and neo-inositol  

E-Print Network (OSTI)

A molecular dynamics simulation of the melting points and glass transition temperatures of myo molecular potentials for atomistic simulation studies COMPASS H. Sun, J. Phys. Chem. B 102, 7338 1998 force field and molecular dynamics techniques. Our results show that the calculated heats of sublimation

de Gispert, Adrià

314

Molecular dynamics simulation of erosion and surface evolution of tungsten due to bombardment with deuterium and carbon in  

E-Print Network (OSTI)

Molecular dynamics simulation of erosion and surface evolution of tungsten due to bombardment Available online 24 May 2013 Keywords: Molecular dynamic simulation Carbon irradiation on tungsten t The behavior of tungsten as plasma facing material in fusion environment is investigated using molecular

Harilal, S. S.

315

A survey on automated dynamic malware-analysis techniques and tools  

Science Conference Proceedings (OSTI)

Anti-virus vendors are confronted with a multitude of potentially malicious samples today. Receiving thousands of new samples every day is not uncommon. The signatures that detect confirmed malicious threats are mainly still created manually, so it is ... Keywords: Dynamic analysis, malware

Manuel Egele; Theodoor Scholte; Engin Kirda; Christopher Kruegel

2012-02-01T23:59:59.000Z

316

Computational Particle Dynamic Simulations on Multicore Processors (CPDMu) Final Report â?? Phase I  

SciTech Connect

Statement of Problem - Department of Energy has many legacy codes for simulation of computational particle dynamics and computational fluid dynamics applications that are designed to run on sequential processors and are not easily parallelized. Emerging high-performance computing architectures employ massively parallel multicore architectures (e.g., graphics processing units) to increase throughput. Parallelization of legacy simulation codes is a high priority, to achieve compatibility, efficiency, accuracy, and extensibility. General Statement of Solution - A legacy simulation application designed for implementation on mainly-sequential processors has been represented as a graph G. Mathematical transformations, applied to G, produce a graph representation {und G} for a high-performance architecture. Key computational and data movement kernels of the application were analyzed/optimized for parallel execution using the mapping G {yields} {und G}, which can be performed semi-automatically. This approach is widely applicable to many types of high-performance computing systems, such as graphics processing units or clusters comprised of nodes that contain one or more such units. Phase I Accomplishments - Phase I research decomposed/profiled computational particle dynamics simulation code for rocket fuel combustion into low and high computational cost regions (respectively, mainly sequential and mainly parallel kernels), with analysis of space and time complexity. Using the research team's expertise in algorithm-to-architecture mappings, the high-cost kernels were transformed, parallelized, and implemented on Nvidia Fermi GPUs. Measured speedups (GPU with respect to single-core CPU) were approximately 20-32X for realistic model parameters, without final optimization. Error analysis showed no loss of computational accuracy. Commercial Applications and Other Benefits - The proposed research will constitute a breakthrough in solution of problems related to efficient parallel computation of particle and fluid dynamics simulations. These problems occur throughout DOE, military and commercial sectors: the potential payoff is high. We plan to license or sell the solution to contractors for military and domestic applications such as disaster simulation (aerodynamic and hydrodynamic), Government agencies (hydrological and environmental simulations), and medical applications (e.g., in tomographic image reconstruction). Keywords - High-performance Computing, Graphic Processing Unit, Fluid/Particle Simulation. Summary for Members of Congress - Department of Energy has many simulation codes that must compute faster, to be effective. The Phase I research parallelized particle/fluid simulations for rocket combustion, for high-performance computing systems.

Mark S. Schmalz

2011-07-24T23:59:59.000Z

317

Modeling the Forest or Modeling the Trees A Comparison of System Dynamics and Agent-Based Simulation  

E-Print Network (OSTI)

System Dynamics and Agent-based Simulation are two approaches that use computer simulation for investigating non-linear social and socio-economic systems with a focus on the understanding and qualitative prediction of a system’s behavior. Although the two schools have a broad overlap in research topics they have been relatively unnoticed by each other so far. This paper contributes to the cross-study of System Dynamics and Agent-Based Simulation. It uncovers and contrasts the primary conceptual predispositions underlying the two approaches. Moreover, ideas about how the approaches could be integrated are presented. Key words: System Dynamics, Agent-based Simulation

Nadine Schieritz; Peter M. Milling

2003-01-01T23:59:59.000Z

318

Dynamics Modeling and Loads Analysis of an Offshore Floating Wind Turbine  

SciTech Connect

This report describes the development, verification, and application of a comprehensive simulation tool for modeling coupled dynamic responses of offshore floating wind turbines.

Jonkman, J. M.

2007-12-01T23:59:59.000Z

319

A GAUSSIAN PROCESS BASED APPROACH FOR HANDLING UNCERTAINTY IN VEHICLE DYNAMICS SIMULATION  

E-Print Network (OSTI)

Advances in vehicle modeling and simulation in recent years have led to designs that are safer, easier to handle, and less sensitive to external factors. Yet, the potential of simulation is adversely impacted by its limited ability to predict vehicle dynamics in the presence of uncertainty. A commonly occurring source of uncertainty in vehicle dynamics is the road-tire friction interaction, typically represented through a spatially distributed stochastic friction coefficient. The importance of its variation becomes apparent on roads with ice patches, where if the stochastic attributes of the friction coefficient are correctly factored into real time dynamics simulation, robust control strategies could be designed to improve transportation safety. This work concentrates on correctly accounting in the nonlinear dynamics of a car model for the inherent uncertainty in friction coefficient distribution at the road/tire interface. The outcome of this effort is the ability to quantify the effect of input uncertainty on a vehicle’s trajectory and the associated escalation of risk in driving. By using a space dependent Gaussian ? Address all correspondence to this author.

Kyle Schmitt; Justin Madsen; Mihai Anitescu; Dan Negrut

2008-01-01T23:59:59.000Z

320

Review A New Tool for Epidemiology: The Usefulness of Dynamic-Agent Models in Understanding Place Effects on Health  

E-Print Network (OSTI)

A major focus of recent work on the spatial patterning of health has been the study of how features of residential environments or neighborhoods may affect health. Place effects on health emerge from complex interdependent processes in which individuals interact with each other and their environment and in which both individuals and environments adapt and change over time. Traditional epidemiologic study designs and statistical regression approaches are unable to examine these dynamic processes. These limitations have constrained the types of questions asked, the answers received, and the hypotheses and theoretical explanations that are developed. Agent-based models and other systems-dynamics models may help to address some of these challenges. Agent-based models are computer representations of systems consisting of heterogeneous microentities that can interact and change/adapt over time in response to other agents and features of the environment. Using these models, one can observe how macroscale dynamics emerge from microscale interactions and adaptations. A number of challenges and limitations exist for agent-based modeling. Nevertheless, use of these dynamic models may complement traditional epidemiologic analyses and yield additional insights into the processes involved and the interventions that may be most useful. computer simulation; environment and public health; epidemiologic methods; health behavior; models, theoretical; residence characteristics; systems theory

Amy H. Auchincloss; Ana V. Diez Roux

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Dynamic quantum clustering: a tool for visual exploration of structures in data  

SciTech Connect

A given set of data-points in some feature space may be associated with a Schroedinger equation whose potential is determined by the data. This is known to lead to good clustering solutions. Here we extend this approach into a full-fledged dynamical scheme using a time-dependent Schroedinger equation. Moreover, we approximate this Hamiltonian formalism by a truncated calculation within a set of Gaussian wave functions (coherent states) centered around the original points. This allows for analytic evaluation of the time evolution of all such states, opening up the possibility of exploration of relationships among data-points through observation of varying dynamical-distances among points and convergence of points into clusters. This formalism may be further supplemented by preprocessing, such as dimensional reduction through singular value decomposition or feature filtering.

Weinstein, Marvin; /SLAC; Horn, David; /Tel Aviv U.

2009-10-17T23:59:59.000Z

322

Beam dynamics and wakefield simulations of the double grating accelerating structure  

Science Conference Proceedings (OSTI)

Laser-driven acceleration in dielectric structures can provide gradients on the order of GeV/m. The small transverse dimension and tiny feature sizes introduce challenges in design, fabrication, and simulation studies of these structures. In this paper we present the results of beam dynamic simulation and short range longitudinal wakefield simulation of the double grating structure. We show the linear trend of acceleration in a dielectric accelerator design and calculate the maximum achievable gradient equal to 0.47E{sub 0} where E0 is maximum electric field of the laser excitation. On the other hand, using wakefield simulations, we show that the loss factor of the structure with 400nm gap size will be 0.12GV/m for a 10fC, 100as electron bunch which is an order of magnitude less than expected gradient near damage threshold of the device.

Najafabadi, B. Montazeri; Byer, R. L.; Ng, C. K.; England, R. J.; Peralta, E. A.; Soong, K.; Noble, R.; Wu, Z. [Stanford University, Stanford, CA (United States); SLAC National Accelerator Laboratory, Menlo Park, CA (United States)

2012-12-21T23:59:59.000Z

323

Validation and verification of MCNP6 as a new simulation tool useful for medical applications  

Science Conference Proceedings (OSTI)

MCNP6, the latest and most advanced LANL transport code, representing a merger of MCNP5 and MCNPX has been Validated and Verified (V&V) against different experimental data and results by other codes relevant to medical applications. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.02 and LAQGSM03.03. We found that MCNP6 describes well data of interest for medical applications measured on both thin and thick targets and agrees very well with similar results obtained with other codes; MCNP6 may be a very useful tool for medical applications We plan to make MCNP6 available to the public via RSICC at Oak Ridge in the middle of 2011 but we are allowed to provide it to friendly US Beta-users outside LANL already now.

Mashnik, Stepan G [Los Alamos National Laboratory

2011-01-06T23:59:59.000Z

324

Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulations in radiation therapy  

SciTech Connect

Purpose: Severe artifacts in kilovoltage-CT simulation images caused by large metallic implants can significantly degrade the conspicuity and apparent CT Hounsfield number of targets and anatomic structures, jeopardize the confidence of anatomical segmentation, and introduce inaccuracies into the radiation therapy treatment planning process. This study evaluated the performance of the first commercial orthopedic metal artifact reduction function (O-MAR) for radiation therapy, and investigated its clinical applications in treatment planning. Methods: Both phantom and clinical data were used for the evaluation. The CIRS electron density phantom with known physical (and electron) density plugs and removable titanium implants was scanned on a Philips Brilliance Big Bore 16-slice CT simulator. The CT Hounsfield numbers of density plugs on both uncorrected and O-MAR corrected images were compared. Treatment planning accuracy was evaluated by comparing simulated dose distributions computed using the true density images, uncorrected images, and O-MAR corrected images. Ten CT image sets of patients with large hip implants were processed with the O-MAR function and evaluated by two radiation oncologists using a five-point score for overall image quality, anatomical conspicuity, and CT Hounsfield number accuracy. By utilizing the same structure contours delineated from the O-MAR corrected images, clinical IMRT treatment plans for five patients were computed on the uncorrected and O-MAR corrected images, respectively, and compared. Results: Results of the phantom study indicated that CT Hounsfield number accuracy and noise were improved on the O-MAR corrected images, especially for images with bilateral metal implants. The {gamma} pass rates of the simulated dose distributions computed on the uncorrected and O-MAR corrected images referenced to those of the true densities were higher than 99.9% (even when using 1% and 3 mm distance-to-agreement criterion), suggesting that dose distributions were clinically identical. In all patient cases, radiation oncologists rated O-MAR corrected images as higher quality. Formerly obscured critical structures were able to be visualized. The overall image quality and the conspicuity in critical organs were significantly improved compared with the uncorrected images: overall quality score (1.35 vs 3.25, P= 0.0022); bladder (2.15 vs 3.7, P= 0.0023); prostate and seminal vesicles/vagina (1.3 vs 3.275, P= 0.0020); rectum (2.8 vs 3.9, P= 0.0021). The noise levels of the selected ROIs were reduced from 93.7 to 38.2 HU. On most cases (8/10), the average CT Hounsfield numbers of the prostate/vagina on the O-MAR corrected images were closer to the referenced value (41.2 HU, an average measured from patients without metal implants) than those on the uncorrected images. High {gamma} pass rates of the five IMRT dose distribution pairs indicated that the dose distributions were not significantly affected by the CT image improvements. Conclusions: Overall, this study indicated that the O-MAR function can remarkably reduce metal artifacts and improve both CT Hounsfield number accuracy and target and critical structure visualization. Although there was no significant impact of the O-MAR algorithm on the calculated dose distributions, we suggest that O-MAR corrected images are more suitable for the entire treatment planning process by offering better anatomical structure visualization, improving radiation oncologists' confidence in target delineation, and by avoiding subjective density overrides of artifact regions on uncorrected images.

Li Hua; Noel, Camille; Chen, Haijian; Harold Li, H.; Low, Daniel; Moore, Kevin; Klahr, Paul; Michalski, Jeff; Gay, Hiram A.; Thorstad, Wade; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States); Department of Radiation Oncology, University of California San Diego, San Diego, California 92093 (United States); Philips Healthcare System, Cleveland, Ohio 44143 (United States); Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)

2012-12-15T23:59:59.000Z

325

PINO - a tool for simulating neutron spectra resulting from the 7Li(p,n) reaction  

E-Print Network (OSTI)

The 7Li(p,n) reaction in combination with a 3.7 MV Van de Graaff accelerator was routinely used at FZK to perform activation as well as time-of-flight measurements with neutrons in the keV-region. Planned new setups with much higher proton currents like SARAF and FRANZ and the availability of liquid-lithium target technology will trigger a renaissance of this method. A detailed understanding of the neutron spectrum is not only important during the planning phase of an experiment, but also during for the analysis of activation experiments. Therefore, the Monte-Carlo based program PINO (Protons In Neutrons Out) was developed, which allows the simulation of neutron spectra considering the geometry of the setup and the proton-energy distribution.

R. Reifarth; M. Heil; F. Käppeler; R. Plag

2013-10-06T23:59:59.000Z

326

Two-dimensional computational fluid dynamics and conduction simulations of heat transfer in window frames with internal cavities - Part 1: Cavities only  

E-Print Network (OSTI)

of heat fluxes from CFD and conduction simulations for theapproach to solve the conduction heat-transfer equation. TheFluid Dynamics and Conduction Simulations of Heat Transfer

Gustavsen, Arild; Kohler, Christian; Arasteh, Dariush; Curcija, Dragan

2003-01-01T23:59:59.000Z

327

Evaluation of System Level Modeling and Simulation Tools in Support of Savannah River Site Liquid Waste Process  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Savannah River Site Liquid Waste Process Savannah River Site Liquid Waste Process June 2009 Monica C. Regalbuto Office of Waste Processing DOE/EM Kevin G. Brown Vanderbilt University and CRESP David W. DePaoli Oak Ridge National Laboratory Candido Pereira Argonne National Laboratory John R. Shultz Office of Waste Processing DOE/EM Sahid C. Smith Office of Waste Processing DOE/EM External Technical Review for Evaluation of System Level Modeling and Simulation Tools in Support of Savannah River Site Liquid Waste Process June 2009 ACKNOWLEDGEMENTS The Review Team thanks Ms. Sonitza Blanco, Team Lead Planning and Coordination Waste Disposition Project U.S. Department of Energy Savannah River Operations Office and Mr. Pete Hill, Liquid Waste Planning Manager for Washington Savannah River Company, for their

328

External Technical Review for Evaluation of System Level Modeling and Simulation Tools in Support of Hanford Site Liquid Waste Process  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hanford Site Liquid Waste Process Hanford Site Liquid Waste Process September 2009 Monica C. Regalbuto Office of Waste Processing DOE/EM Kevin G. Brown Vanderbilt University and CRESP David W. DePaoli Oak Ridge National Laboratory Candido Pereira Argonne National Laboratory John R. Shultz Office of Waste Processing DOE/EM External Technical Review for Evaluation of System Level Modeling and Simulation Tools in Support of Hanford Site Liquid Waste Process September 2009 Acknowledgements The Review Team thanks Mr. Glyn Trenchard, Team Lead for Planning and Coordination Waste Disposition Project, U.S. Department of Energy--Office of River Protection, Mr. Paul Rutland, RPP System Planning Manager for Washington River Protection Solutions, and Mr. Ernie Lee,

329

Beam dynamics simulations and measurements at the Project X Test Facility  

Science Conference Proceedings (OSTI)

Project X, under study at Fermilab, is a multitask high-power superconducting RF proton beam facility, aiming to provide high intensity protons for rare processes experiments and nuclear physics at low energy, and simultaneously for the production of neutrinos, as well as muon beams in the long term. A beam test facility - former known as High Intensity Neutrino Source (HINS) - is under commissioning for testing critical components of the project, e.g. dynamics and diagnostics at low beam energies, broadband beam chopping, RF power generation and distribution. In this paper we describe the layout of the test facility and present beam dynamics simulations and measurements.

Gianfelice-Wendt, E.; Scarpine, V.E.; Webber, R.C.; /Fermilab

2011-03-01T23:59:59.000Z

330

Interactions between Ether Phospholipids and Cholesterol as Determined by Scattering and Molecular Dynamics Simulations  

SciTech Connect

Cholesterol and ether lipids are ubiquitous in mammalian cell membranes, and their interactions are crucial in ether lipid mediated cholesterol trafficking. We report on cholesterol s molecular interactions with ether lipids as determined using a combination of small-angle neutron and Xray scattering, and all-atom molecular dynamics (MD) simulations. A scattering density profile model for an ether lipid bilayer was developed using MD simulations, which was then used to simultaneously fit the different experimental scattering data. From analysis of the data the various bilayer structural parameters were obtained. Surface area constrained MD simulations were also performed to reproduce the experimental data. This iterative analysis approach resulted in good agreement between the experimental and simulated form factors. The molecular interactions taking place between cholesterol and ether lipids were then determined from the validated MD simulations. We found that in ether membranes cholesterol primarily hydrogen bonds with the lipid headgroup phosphate oxygen, while in their ester membrane counterparts cholesterol hydrogen bonds with the backbone ester carbonyls. This different mode of interaction between ether lipids and cholesterol induces cholesterol to reside closer to the bilayer surface, dehydrating the headgroup s phosphate moiety. Moreover, the three-dimensional lipid chain spatial density distribution around cholesterol indicates anisotropic chain packing, causing cholesterol to tilt. These insights lend a better understanding of ether lipid-mediated cholesterol trafficking and the roles that the different lipid species have in determining the structural and dynamical properties of membrane associated biomolecules.

Pan, Jianjun [ORNL; Cheng, Xiaolin [ORNL; Heberle, Frederick A [ORNL; Mostofian, Barmak [ORNL; Kucerka, Norbert [Canadian Neutron Beam Centre and Comelius University (Slovakia); Drazba, Paul [ORNL; Katsaras, John [ORNL

2012-01-01T23:59:59.000Z

331

An Event-Driven Hybrid Molecular Dynamics and Direct Simulation Monte Carlo Algorithm  

Science Conference Proceedings (OSTI)

A novel algorithm is developed for the simulation of polymer chains suspended in a solvent. The polymers are represented as chains of hard spheres tethered by square wells and interact with the solvent particles with hard core potentials. The algorithm uses event-driven molecular dynamics (MD) for the simulation of the polymer chain and the interactions between the chain beads and the surrounding solvent particles. The interactions between the solvent particles themselves are not treated deterministically as in event-driven algorithms, rather, the momentum and energy exchange in the solvent is determined stochastically using the Direct Simulation Monte Carlo (DSMC) method. The coupling between the solvent and the solute is consistently represented at the particle level, however, unlike full MD simulations of both the solvent and the solute, the spatial structure of the solvent is ignored. The algorithm is described in detail and applied to the study of the dynamics of a polymer chain tethered to a hard wall subjected to uniform shear. The algorithm closely reproduces full MD simulations with two orders of magnitude greater efficiency. Results do not confirm the existence of periodic (cycling) motion of the polymer chain.

Donev, A; Garcia, A L; Alder, B J

2007-07-30T23:59:59.000Z

332

Large-scale molecular dynamics simulations of shock-induced plasticity, phase transformations, and detonation  

SciTech Connect

Modern computers enable routine multimillion-atom molecular dynamics simulations of shock propagation in solids using realistic interatomic potentials, and offer a direct insight into the atomistic processes underlying plasticity, phase transformations, and the detonation of energetic materials. Past, present, and prospects for future simulations will be discussed in the context of prototypical systems for each of these three classes of problems. Initial samples ranging from perfect single crystals, to those with specific isolated defects, to full-fledged polycrystalline materials will be considered.

Germann, T. C. (Timothy C.)

2001-06-01T23:59:59.000Z

333

A new battery-charging method suggested by molecular dynamics simulations  

E-Print Network (OSTI)

Based on large-scale molecular dynamics simulations, we propose a new charging method that should be capable of charging a Lithium-ion battery in a fraction of the time needed when using traditional methods. This charging method uses an additional applied oscillatory electric field. Our simulation results show that this charging method offers a great reduction in the average intercalation time for Li+ ions, which dominates the charging time. The oscillating field not only increases the diffusion rate of Li+ ions in the electrolyte but, more importantly, also enhances intercalation by lowering the corresponding overall energy barrier.

Hamad, Ibrahim Abou; Wipf, D; Rikvold, P A; 10.1039/b920970k

2010-01-01T23:59:59.000Z

334

Energy of one-dimensional diatomic elastic granular gas: Theory and molecular dynamics Simulation  

E-Print Network (OSTI)

One-dimensional ideal diatomic gas is simulated through possible types of motion of a molecule. Energy of each type of its motion is calculated from theory and numerical method. Calculation of kinetic energy of an atom in translational-vibrational motion is not analytically simple, but it can be solved by numerical method of molecular dynamic simulation. This paper justifies that kinetic energy of a diatomic molecule can be determined by two different approaches. The first is the sum of kinetic energy of each atom and second is the sum of kinetic energy of translational motion and vibrational motion.

Khotimah, Siti Nurul; Widayani,; Waris, Abdul

2011-01-01T23:59:59.000Z

335

A Perspective on WAMS Analysis Tools for Tracking of Oscillatory Dynamics  

Science Conference Proceedings (OSTI)

Over roughly the past two decades, an architecture has evolved for using Wide Area Measurement Systems to monitor power-system oscillatory dynamics. This includes, but is not limited to, the use of Phasor Measurement Units and advanced signal processing algorithms. Today, this architecture is further evolving toward real-time operation applications. This paper provides a perspective upon these analysis approaches, and defines and clarifies analysis operations, interactions, and application conditions. An overview of WAMS analysis approaches is given along with several examples from the western North American Power System.

Hauer, John F.; Trudnowski, Daniel; DeSteese, John G.

2007-06-28T23:59:59.000Z

336

PICsIM - the INTEGRAL/IBIS/PICsIT Observation Simulation Tool for Prototype Software Evaluation  

E-Print Network (OSTI)

The INTEGRAL satellite is an observatory-class gamma-ray telescope due for launch in early 2002. It comprises two main instruments, one optimised for imaging (IBIS) and the other for spectroscopy (SPI). The PICsIT telescope is the high energy (150 keV - 10 MeV) plane of the IBIS imager and consists of 8 individual modules of 512 detection elements. The modules are arranged in a 4 x 2 pattern, while the pixels are in a 16 x 32 array. This layout, which includes a dead area equivalent to one pixel width between each module, together with the event selection procedure, which (in standard mode) does not allow the identification of coincidences between separate modules, leads to a non-uniformity of the background which is significantly different for single-site events and for multiple energy deposits. Other sources of background variations range from the separate low energy detector, situated immediately above the PICsIT plane, to the large mass of the SPI telescope at a short distance to one side. The algorithms for performing all the imaging and spectral deconvolution for PICsIT are currently being produced for delivery to the INTEGRAL Science Data Centre. In order to maximise the information which may be extracted from the PICsIT data, we have designed a prototyping environment which consists of a GUI to a highly structured and modular set of procedures which allows the easy simulation of observations from the data collection phase through to the final image production and analysis.

J. B. Stephen; L. Foschini

2001-01-09T23:59:59.000Z

337

Development of a carburizing and quenching simulation tool: Determination of heat transfer boundary conditions in salt  

Science Conference Proceedings (OSTI)

In the numerical simulation of the quenching of steel parts, it is desirable to limit the thermal problem to one of conduction in the solid part, with Newtonian cooling on the surface. This avoids the solution of highly transient, non-Boussinesq conjugate heat transfer problems which often involve mixed convection. Of course, the heat transfer coefficient h{sub 1} is in general a function of local surface temperature, and may depend strongly on the part geometry and other parameters. In order to obtain appropriate heat transfer coefficients for quenching thick rings in salt, we solve the conjugate heat transfer problem for representative geometries and determine the heat transfer coefficient from the calculated heat flux at the solid-fluid interface. This is done in a two-stage approach. First, we examine fully coupled solutions obtained from first principles without adjustable empirical parameters using an adaptive finite difference code applicable to simple shapes. The purpose of this part of the procedure is to gain insight into the physics of immersion, free convection and forced convection and to determine the most appropriate forms of the physical properties in the salt. Validation for simple shapes is accomplished by comparison with experimental data reported in the literature. Second, empirical modifications to physical properties and simplified governing equations are used to account for conduction-dominated heat transfer on initial contact and subsequent forced convection during immersion, based on results of the first calculations, so that a commercial finite-volume CFD code can be used to model complex shapes and flow in a quench tank. These results are compared with experimental data for thick rings quenched in salt, and used to calculate surface heat transfer coefficients as functions of temperature and location from the resulting heat flux at the part surface.

Shick, D. [Torrington Co., CT (United States); Walton, H. [Torrington Co., Rutherfordton, NC (United States); Chenoweth, D.R. [Sandia National Lab., Livermore, CA (United States)] [and others

1996-10-01T23:59:59.000Z

338

Bayesian uncertainty quantification and propagation in molecular dynamics simulations: A high performance computing framework  

Science Conference Proceedings (OSTI)

We present a Bayesian probabilistic framework for quantifying and propagating the uncertainties in the parameters of force fields employed in molecular dynamics (MD) simulations. We propose a highly parallel implementation of the transitional Markov chain Monte Carlo for populating the posterior probability distribution of the MD force-field parameters. Efficient scheduling algorithms are proposed to handle the MD model runs and to distribute the computations in clusters with heterogeneous architectures. Furthermore

Panagiotis Angelikopoulos; Costas Papadimitriou; Petros Koumoutsakos

2012-01-01T23:59:59.000Z

339

A Gaussian process-based approach for handling uncertainty in vehicle dynamics simulation.  

Science Conference Proceedings (OSTI)

Advances in vehicle modeling and simulation in recent years have led to designs that are safer, easier to handle, and less sensitive to external factors. Yet, the potential of simulation is adversely impacted by its limited ability to predict vehicle dynamics in the presence of uncertainty. A commonly occurring source of uncertainty in vehicle dynamics is the road-tire friction interaction, typically represented through a spatially distributed stochastic friction coefficient. The importance of its variation becomes apparent on roads with ice patches, where if the stochastic attributes of the friction coefficient are correctly factored into real time dynamics simulation, robust control strategies could be designed to improve transportation safety. This work concentrates on correctly accounting in the nonlinear dynamics of a car model for the inherent uncertainty in friction coefficient distribution at the road/tire interface. The outcome of this effort is the ability to quantify the effect of input uncertainty on a vehicle's trajectory and the associated escalation of risk in driving. By using a space-dependent Gaussian process, the statistical representation of the friction coefficient allows for consistent space dependence of randomness. The approach proposed allows for the incorporation of noise in the observed data and a nonzero mean for inhomogeneous distribution of the friction coefficient. Based on the statistical model considered, consistent friction coefficient sample distributions are generated over large spatial domains of interest. These samples are subsequently used to compute and characterize the statistics associated with the dynamics of a nonlinear vehicle model. The information concerning the state of the road and thus the friction coefficient is assumed available (measured) at a limited number of points by some sensing device that has a relatively homogeneous noise field (satellite picture or ground sensors, for instance). The methodology proposed can be modified to incorporate information that is sensed by each individual car as it advances along its trajectory.

Schmitt, K.; Madsen, J.; Anitescu, M.; Negrut, D.; Mathematics and Computer Science; Univ. of Wisconsin at Madison

2009-01-01T23:59:59.000Z

340

Finite Element Modelling and Molecular Dynamic Simulations of Carbon nanotubes/ Polymer Composites  

E-Print Network (OSTI)

Modeling of single-walled carbon nanotubes, multi-walled nanotubes and nanotube reinforced polymer composites using both the Finite Element method and the Molecular Dynamic simulation technique is presented. Nanotubes subjected to mechanical loading have been analyzed. Elastic moduli and thermal coefficient of expansion are calculated and their variation with diameter and length is investigated. In particular, the nanotubes are modeled using 3D elastic beam finite elements with six degrees of freedom at each node. The difficulty in modeling multi walled nanotubes is the van der Waal's forces between adjacent layers which are geometrically non linear in nature. These forces are modeled using truss elements. The nanotube-polymer interface in a nano-composite is modeled on a similar basis. While performing the molecular dynamic simulations, the geometric optimization is performed initially to obtain the minimized configuration and then the desired temperature is attained by rescaling the velocities of carbon atoms in the nanotube. Results show that the Young's modulus increases with tube diameter in molecular mechanics whereas decreases in molecular dynamics since the inter-atomic potential due to chemical reactions between the atoms is taken into consideration in molecular dynamics unlike in molecular mechanics.

Gaddamanugu, Dhatri

2009-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
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341

A molecular dynamics simulation of DNA damage induction by ionizing radiation  

E-Print Network (OSTI)

We present a multi-scale simulation of early stage of DNA damages by the indirect action of hydroxyl ($^\\bullet$OH) free radicals generated by electrons and protons. The computational method comprises of interfacing the Geant4-DNA Monte Carlo with the ReaxFF molecular dynamics software. A clustering method was employed to map the coordinates of $^\\bullet$OH-radicals extracted from the ionization track-structures onto nano-meter simulation voxels filled with DNA and water molecules. The molecular dynamics simulation provides the time evolution and chemical reactions in individual simulation voxels as well as the energy-landscape accounted for the DNA-$^\\bullet$OH chemical reaction that is essential for the first principle enumeration of hydrogen abstractions, chemical bond breaks, and DNA-lesions induced by collection of ions in clusters less than the critical dimension which is approximately 2-3 \\AA. We show that the formation of broken bonds leads to DNA base and backbone damages that collectively propagate ...

Abolfath, Ramin M; Chen, Zhe J; Nath, Ravinder

2013-01-01T23:59:59.000Z

342

Dissipative Particle Dynamics Simulation of Pore-Scale Multiphase Fluid Flow  

Science Conference Proceedings (OSTI)

Multiphase fluid flow through porous media involves complex fluid dynamics, and it is difficult to model such complex behavior, on the pore scale, using grid-based continuum models. In this paper, the application of dissipative particle dynamics (DPD), a relatively new mesoscale method, to the simulation of pore-scale multiphase fluid flows under a variety of flow conditions is described. We demonstrate that the conventional DPD method using purely repulsive conservative (nondissipative) particle-particle interactions is capable of modeling single-phase flow fields in saturated porous media. In order to simulate unsaturated multiphase flow through porous media, we applied a modified model for the conservative particle-particle interactions that combines short-range repulsive and long-range attractive interactions. This form for the conservative particle-particle interactions allows the behavior of multiphase systems consisting of gases, liquids, and solids to be simulated. We also demonstrated that the flow of both wetting and nonwetting fluids through porous media can be simulated by controlling the ratios between the fluid-fluid and fluid-solid (fluid-wall) interparticle interaction strengths.

Paul Meakin; Hai Huang; Moubin Liu

2007-04-01T23:59:59.000Z

343

A multi-scale approach to molecular dynamics simulations of shock waves  

DOE Green Energy (OSTI)

Study of the propagation of shock waves in condensed matter has led to new discoveries ranging from new metastable states of carbon [1] to the metallic conductivity of hydrogen in Jupiter, [2] but progress in understanding the microscopic details of shocked materials has been extremely difficult. Complications can include the unexpected formation of metastable states of matter that determine the structure, instabilities, and time-evolution of the shock wave. [1,3] The formation of these metastable states can depend on the time-dependent thermodynamic pathway that the material follows behind the shock front. Furthermore, the states of matter observed in the shock wave can depend on the timescale on which observation is made. [4,1] Significant progress in understanding these microscopic details has been made through molecular dynamics simulations using the popular non-equilibrium molecular dynamics (NEMD) approach to atomistic simulation of shock compression. [5] The NEMD method involves creating a shock at one edge of a large system by assigning some atoms at the edge a fixed velocity. The shock propagates across the computational cell to the opposite side. The computational work required by NEMD scales at least quadratically in the evolution time because larger systems are needed for longer simulations to prevent the shock wave from reflecting from the edge of the computational cell and propagating back into the cell. When quantum mechanical methods with poor scaling of computational effort with system size are employed, this approach to shock simulations rapidly becomes impossible.

Reed, E J; Fried, L E; Manaa, M R; Joannopoulos, J D

2004-09-03T23:59:59.000Z

344

Molecular dynamics simulations of swift heavy ion induced defect recovery in SiC  

SciTech Connect

Swift heavy ions induce a high density of electronic excitations that can cause the formation of amorphous ion tracks in insulators. No ion tracks have been observed in the semiconductor SiC, but recent experimental work suggests that irradiation damaged SiC can undergo defect recovery under swift heavy ion irradiation. It is believed that local heating of the lattice due to the electronic energy deposition can anneal, and thereby recover, some of the disordered structure. We simulate the local heating due to the ions by the inelastic thermal spike model and perform molecular dynamics simulations of dierent model damage states to study the defect recovery on an atomistic level. We find significant recovery of point defects and a disordered layer, as well as recrystallization at the amorphous-to-crystalline interface of an amorphous layer. The simulation results support the swift heavy ion annealing hypothesis.Swift heavy ions induce a high density of electronic excitations that can cause the formation of amorphous ion tracks in insulators. No ion tracks have been observed in the semiconductor SiC, but recent experimental work suggests that irradiation damaged SiC can undergo defect recovery under swift heavy ion irradiation. It is believed that local heating of the lattice due to the electronic energy deposition can anneal, and thereby recover, some of the disordered structure. We simulate the local heating due to the ions by the inelastic thermal spike model and perform molecular dynamics simulations of dierent model damage states to study the defect recovery on an atomistic level. We find significant recovery of point defects and a disordered layer, as well as recrystallization at the amorphous-to-crystalline interface of an amorphous layer. The simulation results support the swift heavy ion annealing hypothesis.

Backman, Marie [University of Tennessee, Knoxville (UTK); Toulemonde, Marcel [CEA-CNRS-ENSICAEN-University of Caen, FRANCE; Pakarinen, Olli H [University of Helsinki; Juslin, Niklas [University of Tennessee, Knoxville (UTK); Djurabekova, Flyura [University of Helsinki; Nordlund, Kai [University of Helsinki; Debelle, Aurelien [Universite Paris Sud, Orsay, France; Weber, William J [ORNL

2013-01-01T23:59:59.000Z

345

Defect microstructural evolution in ion irradiated metallic nanofoils: Kinetic Monte Carlo simulation versus cluster dynamics modeling and in situ transmission electron microscopy experiments  

SciTech Connect

Understanding materials degradation under intense irradiation is important for the development of next generation nuclear power plants. Here we demonstrate that defect microstructural evolution in molybdenum nanofoils in situ irradiated and observed on a transmission electron microscope can be reproduced with high fidelity using an object kinetic Monte Carlo (OKMC) simulation technique. Main characteristics of defect evolution predicted by OKMC, namely, defect density and size distribution as functions of foil thickness, ion fluence and flux, are in excellent agreement with those obtained from the in situ experiments and from previous continuum-based cluster dynamics modeling. The combination of advanced in situ experiments and high performance computer simulation/modeling is a unique tool to validate physical assumptions/mechanisms regarding materials response to irradiation, and to achieve the predictive power for materials stability and safety in nuclear facilities.

Xu Donghua; Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Li Meimei [Division of Nuclear Engineering, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Kirk, Marquis A. [Division of Materials Science, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2012-09-03T23:59:59.000Z

346

Integrated dynamic and simulation model on coupled closed-loop workstation capacity controls in a multi-workstation production system  

Science Conference Proceedings (OSTI)

In this paper, a dynamic model coupled with a simulation model is introduced to control a multi-workstation production system such that a given performance measure is achieved. In particular, we consider closed loop capacity controls for regulating WIP ...

Tao Wu; Leyuan Shi; Benjamin Quirt; N. A. Duffie

2008-12-01T23:59:59.000Z

347

Detailed Simulations of Atmospheric Flow and Dispersion in Downtown Manhattan: An Application of Five Computational Fluid Dynamics Models  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD) model simulations of urban boundary layers have improved in speed and accuracy so that they are useful in assisting in planning emergency response activities related to releases of chemical or biological agents ...

Steven R. Hanna; Michael J. Brown; Fernando E. Camelli; Stevens T. Chan; William J. Coirier; Sura Kim; Olav R. Hansen; Alan H. Huber; R. Michael Reynolds

2006-12-01T23:59:59.000Z

348

simulations  

E-Print Network (OSTI)

Part 1 of this two-part paper describes the analysis and 2D finite element (FE) simulations for a capacitive incremental position sensor for nanopositioning of microactuator systems with a displacement range of 100 µm or more. Two related concepts for a capacitive incremental position sensor are presented. In an incremental capacitance measurement mode (ICMM), the periodic change in capacitance is measured to determine the relative displacement between two periodic geometries S1 and S2 with a gap distance of ?1 µm. In a constant capacitance measurement mode (CCMM), the distance between S1 and S2 is controlled to keep the capacitance between S1 and S2 constant. Analysis and 2D finite element simulations show that the signal-to-noise ratio for CCMM can be>300 × over ICMM and with less nonlinearity of the position sensor signal. This means that CCMM will perform better in accurate quadrature incremental position detection. A comparison with measurements shows that the 2D finite element simulation method is a useful tool that realistically predicts the capacitance versus displacement for different combinations of periodic geometries. (Some figures in this article are in colour only in the electronic version) 1.

A A Kuijpers; G J M Krijnen; R J Wiegerink; T S J Lammerink; M Elwenspoek

2006-01-01T23:59:59.000Z

349

Simulating dislocation loop internal dynamics and collective diffusion using stochastic differential equations  

Science Conference Proceedings (OSTI)

Nanoscale prismatic loops are modeled via a partial stochastic differential equation that describes an overdamped continuum elastic string, with a view to describing both the internal and collective dynamics of the loop as a function of temperature. Within the framework of the Langevin equation, expressions are derived that relate the empirical parameters of the model, the friction per unit length, and the elastic stiffness per unit length, to observables that can be obtained directly via molecular-dynamics simulations of interstitial or vacancy prismatic loop mobility. The resulting expressions naturally exhibit the properties that the collective diffusion coefficient of the loop (i) scales inversely with the square root of the number of interstitials, a feature that has been observed in both atomistic simulation and in situ TEM investigations of loop mobility, and (ii) the collective diffusion coefficient is not at all dependent on the internal interactions within the loop, thus qualitatively rationalizing past simulation results showing that the characteristic migration energy barrier is comparable to that of a single interstitial, and cluster migration is a result of individual (but correlated) interstitial activity.

Derlet, P. M.; Gilbert, M. R.; Dudarev, S. L. [Condensed Matter Theory Group, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); EURATOM/CCFE Fusion Association, Culham Centre for Fusion Energy, Oxfordshire OX14 3DB (United Kingdom)

2011-10-01T23:59:59.000Z

350

Urban Networks Simulation Tools  

Science Conference Proceedings (OSTI)

Utilities that serve customers using networked secondary, or low-voltage, systems require that technologies be able to model the system and perform load flow and other circuit analyses on both the primary and the networked secondary. Utilities can use commercially available load flow products to model their radial systems, but many older products are unable to accurately model and perform analyses on meshed secondary network systems sourced from multiple primary feeders. Consequently, many utilities are ...

2010-03-31T23:59:59.000Z

351

Simulation model and the dynamics of relative poverty rates in the presence of some social benefits in Romania  

Science Conference Proceedings (OSTI)

This paper presents some simulations of the relative poverty rates values in the presence of some social benefits in the income of persons / households considered in the Household Budget Survey carried out by the National Institute of Statistics of Romania ... Keywords: dynamics, indicators, relative poverty, simulation model, social benefits

Cristina Stroe; Andreea Cambir; Cornelia Barti; Eva Militaru; Silvia Cojanu; Eliza Lungu; Codruta Dragoiu; Isadora Lazar

2011-07-01T23:59:59.000Z

352

Abstract--A stochastic dynamic programming hydrothermal dispatch model to simulate a bid-based market is  

E-Print Network (OSTI)

on dynamic programming that optimizes and validates the bid prices strategies for each power plant in a hydro-thermal, and simulating them as if they were a single power plant. In a hydro-thermal system as the one simulated several plants. Emphasis is given to hydro reservoir modeling and to the assessment of their market power

Catholic University of Chile (Universidad Católica de Chile)

353

Development of dynamic models of reactive distillation columns for simulation and determination of control  

E-Print Network (OSTI)

Dynamic models of a reactive distillation column have been developed and implemented in this work. A model describing the steady state behavior of the system has been built in a first step. The results from this steady state model have been compared to data provided from an industrial collaborator and the reconciled model formed the basis for the development of a dynamic model. Four controlled and four manipulated variables have been determined in a subsequent step and step tests for the manipulated variables were simulated. The data generated by the step responses was used for fitting transfer functions between the manipulated and the controlled variables. RGA analysis was performed to find the optimal pairing for controller design. Feedback controllers of PID type were designed between the paired variables found from RGA and the controllers were implemented on the column model. Both servo and regulatory problems have been considered and tested.

Chakrabarty, Arnab

2004-12-01T23:59:59.000Z

354

Visualization of parallel molecular dynamics simulation on a remote visualization platform  

SciTech Connect

Visualization requires high performance computers. In order to use these shared high performance computers located at national centers, the authors need an environment for remote visualization. Remote visualization is a special process that uses computing resources and data that are physically distributed over long distances. In their experimental environment, a parallel raytracer is designed for the rendering task. It allows one to efficiently visualize molecular dynamics simulations represented by three dimensional ball-and-stick models. Different issues encountered in creating their platform are discussed, such as I/O, load balancing, and data distribution.

Lee, T.Y.; Raghavendra, C.S. [Washington State Univ., Pullman, WA (United States); Nicholas, J.B. [Pacific Northwest Lab., Richland, WA (United States). Molecular Science Research Center

1994-09-01T23:59:59.000Z

355

A Simulation Environment for the Dynamic Evaluation of Disaster Preparedness Policies  

E-Print Network (OSTI)

, PhD; Chris Barrett, PhD r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r D and interventions in the days following disasters. Author Affiliation: Network Dynamics and Simulation Science

Swarup, Samarth

356

A simulation model of Rio Grande wild turkey dynamics in the Edwards Plateau of Texas  

E-Print Network (OSTI)

I investigated the effect of precipitation and predator abundance on Rio Grande wild turkey (Meleagris gallopavo; RGWT) in Texas. My results suggested that RGWT production was strongly correlated with cumulative winter precipitation over the range of the RGWT in Texas. However, I found no evidence that predator abundance influenced RGWT production, although spatial-asynchrony of predator populations at multiple spatial scales might have masked broad-scale effects. Using the results of these analyses, as well as empirical data derived from the literature and from field studies in the southern Edwards Plateau, I developed a stochastic, density-dependent, sex- and agespecific simulation model of wild turkey population dynamics. I used the model to evaluate the effect of alternative harvest management strategies on turkey populations. Sensitivity analysis of the model suggested that shape of the density-dependence relationship, clutch size, hatchability, juvenile sex ratio, poult survival, juvenile survival, and nonbreeding hen mortality most strongly influenced model outcome. Of these, density-dependence, sex ratio, and juvenile survival were least understood and merit further research. My evaluation of fall hen harvest suggested that current rates do not pose a threat to turkey populations. Moreover, it appears that hen harvest can be extended to other portions of the RGWT range without reducing turkey abundance, assuming that population dynamics and harvest rates are similar to those in the current fall harvest zone. Finally, simulation of alternative hen harvest rates suggested that rates ?5% of the fall hen population resulted in significant declines in the simulated population after 25 years, and rates ?15% resulted in significant risk of extinction to the simulated population.

Schwertner, Thomas Wayne

2003-05-01T23:59:59.000Z

357

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

Updated ModEn object-oriented simulation, energy simulation, controls, energy audit, energy-saving, energy performance, dynamic simulation, research, education, heating, air...

358

Cell dynamics simulation of droplet and bridge formation within striped nano-capillaries  

E-Print Network (OSTI)

The kinetics of droplet and bridge formation within striped nano-capillaries is studied when the wetting film grows via interface-limited growth. The phenomenological time-dependent Ginzburg-Landau (TDGL)-type model with thermal noise is used and numerically solved using the cell dynamics method. The model is two-dimensional and consists of undersaturated vapor confined within a nano-capillary made of two infinitely wide flat substrates. The surface of the substrate is chemically heterogeneous with a single stripe of lyophilic domain that exerts long-range attractive potential to the vapor molecule. The dynamics of nucleation and subsequent growth of droplet and bridge can be simulated and visualized. In particular, the evolution of the morphology from droplet or bump to bridge is clearly identified. Crucial role played by the substrate potential on the morphology of bridge of nanoscopic size is clarified. Nearly temperature-independent evolution of capillary condensation is predicted when the interface-limited growth dominates. In addition, it is shown that the dynamics of capillary condensation follows the scenario of capillary condensation proposed by Everett and Haynes three decades ago.

Masao Iwamatsu

2007-08-13T23:59:59.000Z

359

Dynamics  

NLE Websites -- All DOE Office Websites (Extended Search)

Hydration Hydration Water on Rutile Studied by Backscattering Neutron Spectroscopy and Molecular Dynamics Simulation E. Mamontov,* ,† D. J. Wesolowski, ‡ L. Vlcek, § P. T. Cummings, §,| J. Rosenqvist, ‡ W. Wang, ⊥ and D. R. Cole ‡ Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6473, Chemical Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, Department of Chemical Engineering, Vanderbilt UniVersity, NashVille, Tennessee 37235-1604, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6496, and EnVironmental Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6036 ReceiVed: December 20, 2007; ReVised Manuscript ReceiVed: June 4, 2008 The high energy resolution, coupled with the wide dynamic range, of the new backscattering

360

Equation of state of dense plasmas by ab initio simulations: Bridging the gap between quantum molecular dynamics and orbital-free molecular dynamics at high temperature  

SciTech Connect

The applicability of quantum molecular dynamics to the calculation of the equation of state of a dense plasma is limited at high temperature by computational cost. Orbital-free molecular dynamics, based on the Thomas-Fermi semiclassical approximation and possibly on a gradient correction, is the only simulation method currently available at high temperature. We show in the case of a dense boron plasma that the two approaches give pressures differing by a few percent even at temperatures as high as a few tens of electron-volts. We indicate how the pressures obtained by orbital-free molecular dynamics can be corrected in order to appear as a limit of the quantum molecular dynamics results as temperature increases. We thus obtain a method to calculate the equation of state of a dense plasma up to high temperatures where quantum molecular dynamics cannot be directly implemented.

Danel, J.-F.; Kazandjian, L.; Zerah, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

2012-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

How trehalose protects DNA in the dry state: a molecular dynamics simulation  

E-Print Network (OSTI)

Molecular dynamics simulations were conducted on a system consisting of a decamer DNA solvated by trehalose and water (molecular ratio= 1:2), to mimic a relatively dry state for the DNA molecule. Simulations were performed at two different temperatures, 300 K and 450 K. The B-form DNA structure was shown to be stable at both temperatures. The analysis of hydrogen bonds between trehalose/water and DNA revealed that trehalose and backbone DNA formed the largest number of hydrogen bonds and thus constituted the major effect of structural protection for DNA. The number of hydrogen bonds formed by each OH group of trehalose with the backbone DNA was compared. Different types of trehalose-DNA interactions were analyzed, with no prevalent pattern recognized. Diffusion constants for trehalose and water were also calculated, suggesting a glassy/viscose state of the simulation system. It is believed that trehalose protects DNA in the dry state through the network of hydrogen bonds built by the sugars, which reduces the structural fluctuations of DNA and prevents its denaturation.

Fu, Xuebing

2008-08-01T23:59:59.000Z

362

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion–solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, C.; Xue, J. M.; Zhang, Y.; Morris, J. R.; Zhu, Zh.; Gao, Yanfei; Wang, Y. G.; Yan, S.; Weber, William

2012-01-01T23:59:59.000Z

363

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (< {approx} 25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, Chune [Peking University; Xue, Jianming [Peking University; Zhang, Yanwen [ORNL; Morris, James R [ORNL; Zhu, Zihua [Pacific Northwest National Laboratory (PNNL); Gao, Yuan [Peking University; Wang, Yugang [Peking University; Yan, Sha [Peking University; Weber, William J [ORNL

2012-01-01T23:59:59.000Z

364

A Finite Element-Multibody Dynamics Co-simulation Methodology Applied to FAST  

E-Print Network (OSTI)

A co-simulation methodology is explored whereby a finite element code and a multi-body dynamics code featuring flexible cantilevered beams can be coupled and interactively executed. The floating frame of reference formulation is used to develop the equations of motion. The floating frame is fixed at the blade root. Such a formulation results in ordinary differential equations without added algebraic constraints. A variety of loose coupling and tight coupling schemes are examined for this problem. To synchronize the coupling variables, a Gauss-Seidel type iterative algorithm is used. The resulting fixed-point iterations are accelerated using Aitken’s adaptive relaxation technique. The methodology is evaluated for FAST, a wind turbine aeroelastic simulation code developed by NREL. As with FAST, many multi-body codes which can model flexibility employ modal methods. A proposed addition for FAST to simulate flexible effects using a finite element method module offers a potential to include a variety of non-linearities and also provides possibilities for using a high-fidelity aerodynamics module. The coupling schemes are compared and their applicability and limitations for different scenarios are pointed out. Results validating the approach are provided.

Suryakumar, Vishvas Samuel

2013-05-01T23:59:59.000Z

365

Molecular dynamics simulations of ion range profiles for heavy ions in light targets  

SciTech Connect

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (<25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Lan, Chune; Xue, Jianming; Zhang, Yanwen; Morris, James R.; Zhu, Zihua; Gao, Yuan; Wang, Yugang; Yan, Sha; Weber, William J.

2012-09-01T23:59:59.000Z

366

Molecular Dynamics Simulation of the Transport Properties of Molten Transuranic Chloride Salts  

E-Print Network (OSTI)

The Accelerator Research Laboratory at Texas A&M is proposing a design for accelerator-driven subcritical fission in molten salt (ADSMS), a system that destroys the transuranic elements in used nuclear fuel. The transuranics (TRU) are the most enduring hazard of nuclear power. TRU contain high radiotoxicity and have half-lives of a thousand to a million years. The ADSMS core is fueled by a homogeneous chloride-based molten salt mixture containing TRUCl3 and NaCl. Certain thermodynamic properties are critical to modeling both the neutronics and heat transfer of an ADSMS system. There is a lack of experimental data on the density, heat capacity, electrical and thermal conductivities, and viscosity of TRUCl3 salt systems. Molecular dynamics simulations using a polarizable ion model (PIM) are employed to determine the density and heat capacity of these melts as a function of temperature. Green-Kubo methods are implemented to calculate the electrical conductivity, thermal conductivity, and viscosity of the salt using the outputs of the simulations. Results for pure molten salt systems are compared to experimental data when possible to validate the potentials used. Here I discuss chloride salt systems of interest, their calculated properties, and possible sources of error for our simulations.

Baty, Austin Alan

2013-05-01T23:59:59.000Z

367

Driving Down HB-LED Costs: Implementation of Process Simulation Tools and Temperature Control Methods of High Yield MOCVD Growth  

SciTech Connect

The overall objective of this multi-faceted program is to develop epitaxial growth systems that meet a goal of 75% (4X) cost reduction in the epitaxy phase of HB-LED manufacture. A 75% reduction in yielded epitaxy cost is necessary in order to achieve the cost goals for widespread penetration of HB-LEDâ??s into back-lighting units (BLU) for LCD panels and ultimately for solid-state lighting (SSL). To do this, the program will address significant improvements in overall equipment Cost of Ownership, or CoO. CoO is a model that includes all costs associated with the epitaxy portion of production. These aspects include cost of yield, capital cost, operational costs, and maintenance costs. We divide the program into three phases where later phases will incorporate the gains of prior phases. Phase one activities are enabling technologies. In collaboration with Sandia National Laboratories we develop a Fluent-compatible chemistry predictive model and a set of mid-infrared and near-ultraviolet pyrometer monitoring tools. Where previously the modeling of the reactor dynamics were studied within FLUENT alone, here, FLUENT and Chemkin are integrated into a comprehensive model of fluid dynamics and the most advanced transport equations developed for Chemkin. Specifically, the Chemkin model offered the key reaction terms for gas-phase nucleation, a key consideration in the optimization of the MOCVD process. This new predictive model is used to design new MOCVD reactors with optimized growth conditions and the newly developed pyrometers are used monitor and control the MOCVD process temperature to within 0.5°C run-to-run and within each wafer. This portion of the grant is in collaboration with partners at Sandia National Laboratories. Phase two activities are continuous improvement projects which extend the current reactor platform along the lines of improved operational efficiency, improved systems control for throughput, and carrier modifications for increased yield. Programmatically, improvements made in Phase I are applied to developments of Phase II when applicable. Phase three is the culmination of the individual tasks from both phases one and two applied to proposed production platforms. We selectively combine previously demonstrated tasks and other options to develop a high-volume production-worthy MOCVD system demonstrating >3x throughput, 1.3x capital efficiency, and 0.7x cost of ownership. In a parallel demonstration we validate the concept of an improved, larger deposition system which utilizes the predictive modeling of chemistry-based flow analysis and extensions of the improvements demonstrated on the current platforms. This validation includes the build and testing of a prototype version of the hardware and demonstration of 69% reduction in the cost of ownership. Also, in this phase we present a stand-alone project to develop a high-temperature system which improves source efficiency by 30% while concurrently increasing growth rate by 1.3x. The material quality is held to the same material quality specifications of our existing baseline processes. The merits of other line item tasks in phase three are discussed for inclusion on next-generation platforms.

William Quinn

2012-04-30T23:59:59.000Z

368

Simulating soil C dynamics with EPIC: Model description and testing against long-term data  

SciTech Connect

Soil carbon sequestration (SCS) has emerged as a technology with significant potential to help stabilize atmospheric CO2 concentrations and thus reduce the threat of global warming. Methods and models are needed to evaluate and recommend SCS practices based on their effects on carbon dynamics and environmental quality. EPIC (Environment Policy Integrated Climate) is a widely used and tested model for simulating many agroecosystem processes including plant growth, crop yield, tillage, wind and water erosion, runoff, soil density, and leaching. Here we describe new C and N modules developed in EPIC built on concepts from the Century model to connect the simulation of soil C dynamics to crop management, tillage methods, and erosion processes. The added C and N routines interact directly with soil moisture, temperature, erosion, tillage, soil density, leaching, and translocation functions in EPIC. Equations were also added to describe the effects of soil texture on soil C stabilization. Lignin concentration is modeled as a sigmoidal function of plant age. EPIC was tested against data from a Conservation Reserve Program (CRP) 6-yr experiment at five sites in three U.S. Great Plains states and a 61-y long-term agronomic experiment in Canada. Mean Square Deviations (MSD) calculated for CRP sites were less than 0.01 kg C2 m2, except for one site where it reached 0.025 kg2 C2 m. MSD values in the 61-y experiment ranged between 0.047 and 0.077 kg C2 m2. In conclusion, the version of the EPIC model presented and tested here contains the necessary algorithms to simulate SCS and improve understanding of the interactions among soil erosion, C dynamics, and tillage. A strength of the model as tested is its ability to explain the variability in crop production, C inputs and SOC and N cycling over a wised range soil, cropping and climatic conditions over periods from 6 to 61 years. For example, at the Breton site over 61 years, EPIC accounted for 69% of the variability in grain yields, 89 % of the variability in C inputs and 91 % of the variability in SOC content in the top 15 cm. Continued development is be needed is in understanding why it overpredicts at low SOC and underpredicts at high SOC. Possibilities now exit to connect the C and N cycling parts of EPIC to algorithms to describe denitrification as driven by C metabolism and oxygen availability.

Izaurralde, R Cesar C.; Williams, Jimmy R.; Mcgill, William B.; Rosenberg, Norman J.; Quiroga Jakas, Maria C.

2006-01-01T23:59:59.000Z

369

Effects of confinement on water structure and dynamics and on proton transport: a molecular simulation study  

E-Print Network (OSTI)

Classical molecular dynamics (MD) simulations are performed to study structural and dynamic properties of water confined within graphite surfaces. The surfaces are separated at distances varying between 7 and 14.5 Å and the water density is held constant at 1g/cc. Results at 298 K show the formation of a well-ordered structure constituted by water layers parallel to the graphite surfaces. The water molecules in the layers in contact with the surface have a tendency to orient their dipole parallel to the surface. Such ice-like structures may have different structural and dynamic properties than those of ice. The calculated mean square displacement reveals that the mobilities of the confined water at a separation of 8 Å become similar to that of low-temperature water (213 K) at the same density, although the structures of water are very different. The temperature at which the mobility of water confined at the separation of 7 Å would become similar to that of bulk low-temperature water was found to be 373K. With respect to the dynamics of confined water, a significant blue shift is observed in the intermolecular vibrational modes associated with the O×××O×××O bending and O×××O stretching of molecules linked by hydrogen bonds. The analysis of the geometry of water clusters confined between two graphite surfaces has been performed using ab initio methods. The ab initio calculations yield two preferential orientations of water molecules which are; 1) one O-H bond points to the surface and the other is parallel; 2) both O-H bonds are parallel to the surface. These orientations agree with those found in our MD simulation results. The calculated energy barriers for proton transfer of the confined H3O+-(H2O) complexes between two graphite model surfaces suggest that the confinement enhances the proton transfer at the separation 6-14.5 Å. When the confinement is high, at a separation of 4 Å, the barrier energies are extremely large. The confinement does not enhance proton transfer when the H3O+-(H2O) complexes are located further from the surfaces by more than 8 Å. As a result, the barrier energies start to increase at the separation of 20 Å.

Hirunsit, Pussana

2007-05-01T23:59:59.000Z

370

Ultrapdeep water blowouts: COMASim dynamic kill simulator validation and best practices recommendations  

E-Print Network (OSTI)

The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world's hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water. While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company's exploration planning and technology suite. To further the development of blowout prevention and control, COMASim Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements. The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim's strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.

Noynaert, Samuel F.

2004-12-01T23:59:59.000Z

371

RPM-SIM Simulator: A Comparison of Simulated Versus Recorded Data (Preprint)  

Science Conference Proceedings (OSTI)

This paper compares simulated versus recorded data for the RPM-SIM simulator, developed at the National Renewable Energy Laboratory's National Wind Technology Center. The simulator was used to study the system dynamics of a wind/diesel hybrid power system. We also provide information on newly developed simulator modules that will be released. The simulator performed extremely well, demonstrating flexibility in making modifications and including specialized modules required for problem solving. We also outline several possible applications for this tool.

Bialasiewicz, J.T.; Muljadi, E.; Nix, G.; Drouilhet, S.

2001-07-25T23:59:59.000Z

372

A structurally complex and dynamic reservoir description for reservoir simulation, Kuparuk River Field, Alaska  

SciTech Connect

The Kupanuk River Field is a structurally complex giant oil field adjacent to the Prudhoe Bay Field on Alaska`s North Slope. Oil is reservoired within two Early Cretaceous shallow marine sandstone formations, separated stratigraphically by an erosionally truncated marine silt/shale. Subjected to several phases of tectonism, this highly compartmentalized reservoir has been developed on regular 160 acre direct line drive patterns. An integrated team of geoscientists and engineers from BP Exploration (Alaska) Inc. and ARCO Alaska Inc. is presently quantifying the benefits of infill drilling at Kuparuk, and identifying the best locations for well placement. The two primary reservoir characteristics believed to impact the effectiveness of infill drilling are large-scale reservoir heterogeneity, and reservoir comparmentation due to faulting. Multiple thin pay zones within the two reservoir intervals are isolated laterally by faults with magnitudes greater than pay zone thickness. A process and tools designed to construct and maintain a structurally complex reservoir description, shared by the geoscientists and reservoir engineers, are described. Cross-discipline integration is aided by the use of Tech*Logic`s IREX 3-D reservoir modeling and visualization application. The unique architecture of the IREX model allows for representation of very complex structural geometries, and facilitates iteration between reservoir description and simulation, along the seismic to simulation continuum. Modifications to the reservoir description are guided by well-level history matching within the constraints of all available geoscience information. The techniques described will be of particular interest to those working on reservoir description and simulation of structurally complex fields.

Walsh, T.P. [Alaska Petrotechnical Services Inc., Anchorage, AK (United States); Leander, M.H.; Wilcox, T.C. [BP Exploration (Alaska) Inc., Anchorage, AK (United States)] [and others

1995-08-01T23:59:59.000Z

373

An efficient algorithm for blade loss simulations applied to a high-order rotor dynamics problem  

E-Print Network (OSTI)

In this thesis, a novel approach is presented for blade loss simulation of an aircraft gas turbine rotor mounted on rolling element bearings with squeeze film dampers, seal rub and enclosed in a flexible housing. The modal truncation augmentation (MTA) method provides an efficient tool for modeling this large order system with localized nonlinearities in the ball bearings. The gas turbine engine, which is composed of the power turbine and gas generator rotors, is modeled with 38 lumped masses. A nonlinear angular contact bearing model is employed, which has ball and race degrees of freedom and uses a modified Hertzian contact force between the races and balls and for the seal rub. This combines a dry contact force and viscous damping force. A flexible housing with seal rub is also included whose modal description is imported from ANSYS. Prediction of the maximum contact load and the corresponding stress on an elliptical contact area between the races and balls is made during the blade loss simulations. A finite-element based squeeze film damper (SFD), which determines the pressure profile of the oil film and calculates damper forces for any type of whirl orbit is utilized in the simulation. The new approach is shown to provide efficient and accurate predictions of whirl amplitudes, maximum contact load and stress in the bearings, transmissibility, thermal growths, maximum and minimum damper pressures and the amount of unbalanced force for incipient oil film cavitation. It requires about 4 times less computational time than the traditional approaches and has an error of less than 5 %.

Parthasarathy, Nikhil Kaushik

2003-12-01T23:59:59.000Z

374

A simple and effective Verlet-type algorithm for simulating Langevin dynamics  

E-Print Network (OSTI)

We present a revision to the well known Stormer-Verlet algorithm for simulating second order differential equations. The revision addresses the inclusion of linear friction with associated stochastic noise, and we analytically demonstrate that the new algorithm correctly reproduces diffusive behavior of a particle in a flat potential. For a harmonic oscillator, our algorithm provides the exact Boltzmann distribution for any value of damping, frequency, and time step for both underdamped and over damped behavior within the usual the stability limit of the Verlet algorithm. Given the structure and simplicity of the method we conclude this approach can trivially be adapted for contemporary applications, including molecular dynamics with extensions such as molecular constraints.

Grønbech-Jensen, Niels

2013-01-01T23:59:59.000Z

375

A simple and effective Verlet-type algorithm for simulating Langevin dynamics  

E-Print Network (OSTI)

We present a revision to the well known Stormer-Verlet algorithm for simulating second order differential equations. The revision addresses the inclusion of linear friction with associated stochastic noise, and we analytically demonstrate that the new algorithm correctly reproduces diffusive behavior of a particle in a flat potential. For a harmonic oscillator, our algorithm provides the exact Boltzmann distribution for any value of damping, frequency, and time step for both underdamped and over damped behavior within the usual the stability limit of the Verlet algorithm. Given the structure and simplicity of the method we conclude this approach can trivially be adapted for contemporary applications, including molecular dynamics with extensions such as molecular constraints.

Niels Grønbech-Jensen; Oded Farago

2012-12-06T23:59:59.000Z

376

Dynamic Monte Carlo simulation of coupled transport through a narrow multiply-occupied pore  

E-Print Network (OSTI)

Dynamic Monte Carlo simulations are used to study coupled transport (co-transport) through sub-nanometer-diameter pores. In this classic Hodgkin-Keynes mechanism, an ion species uses the large flux of an abundant ion species to move against its concentration gradient. The efficiency of co-transport is examined for various pore parameters so that synthetic nanopores can be engineered to maximize this effect. In general, the pore must be narrow enough that ions cannot pass each other and the charge of the pore large enough to attract many ions so that they exchange momentum. Co-transport efficiency increases as pore length increases, but even very short pores exhibit co-transport, in contradiction to the usual perception that long pores are necessary. The parameter ranges where co-transport occurs is consistent with current and near-future synthetic nanopore geometry parameters, suggesting that co-transport of ions may be a new application of nanopores.

Dezs? Boda; Éva Csányi; Dirk Gillespie; Tamás Kristóf

2013-10-08T23:59:59.000Z

377

High-precision molecular dynamics simulation of UO2-PuO2: pair potentials comparison  

E-Print Network (OSTI)

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the rigid ions approximation using high-performance graphics processors (GPU). In the first article we assess 10 most relevant interatomic sets of pair potentials (SPP) by reproduction of solid phase properties of uranium dioxide (UO2) - temperature dependences of the lattice constant, bulk modulus, enthalpy and heat capacity. Measurements were performed with 1K accuracy in a wide temperature range from 300K up to melting point. The best results are demonstrated by two recent SPPs MOX-07 and Yakub-09, which both had been fitted to the recommended thermal expansion in the range of temperatures 300-3100K. Compared with them, the widely used SPPs Basak-03 and Morelon-03 reproduce the experimental data noticeably worse at temperatures above 2500K.

Potashnikov, S I; Nekrasov, K A; Kupryazhkin, A Ya

2011-01-01T23:59:59.000Z

378

Molecular dynamics simulation of interaction of H with vacancy in W  

DOE Green Energy (OSTI)

Molecular dynamics simulations were performed to investigate the interaction between H and vacancy in W using an analytical bond-order potential to describe the interactions between W-W, W-H and H-H. The most stable configuration for H in W is the tetrahedron interstitial site. We calculated the binding energies of an H and a vacancy to an H-vacancy cluster (HnVm) in W, respectively, where n and m ranged from 0 to 10. The binding energy was almost unchanged. The binding energy of a vacancy to H-vacancy cluster is about 0.4eV, which is higher than the binding energy of an H to H-vacancy cluster. Vacancy is much easier to binding with H-vacancy cluster than H. And H is easier to stay in the tetrahedron interstitial site or octahedron interstitial site in bcc W.

Li, Xiaochun; Gao, Fei; Lu, Guang-Hong

2009-09-15T23:59:59.000Z

379

Computational fluid dynamics applications to improve crop production systems  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD), numerical analysis and simulation tools of fluid flow processes have emerged from the development stage and become nowadays a robust design tool. It is widely used to study various transport phenomena which involve ... Keywords: Decision support tools, Greenhouse, Harvesting machines, Sprayers, Tillage

T. Bartzanas; M. Kacira; H. Zhu; S. Karmakar; E. Tamimi; N. Katsoulas; In Bok Lee; C. Kittas

2013-04-01T23:59:59.000Z

380

A combined Event-Driven/Time-Driven molecular dynamics algorithm for the simulation of shock waves in rarefied gases  

Science Conference Proceedings (OSTI)

A novel combined Event-Driven/Time-Driven (ED/TD) algorithm to speed-up the Molecular Dynamics simulation of rarefied gases using realistic spherically symmetric soft potentials is presented. Due to the low density regime, the proposed method correctly ... Keywords: 47.11.Mn, 47.40.Ki, 47.45.-n, 47.61.Cb, Event-Driven MD, Molecular Dynamics, Non-continuum effects, Shock Waves

Paolo Valentini; Thomas E. Schwartzentruber

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Plant-wide dynamic simulation of an IGCC plant with CO2 capture  

Science Conference Proceedings (OSTI)

To eliminate the harmful effects of greenhouse gases, especially that of CO2, future coalfired power plants need to consider the option for CO2 capture. The loss in efficiency for CO2 capture is less in an Integrated Gasification Combined Cycle (IGCC) plant compared to other conventional coal combustion processes. However, no IGCC plant with CO2 capture currently exists in the world. Therefore, it is important to consider the operability and controllability issues of such a plant before it is commercially built. With this objective in mind, a detailed plant-wide dynamic simulation of an IGCC plant with CO2 capture has been developed. The plant considers a General Electric Energy (GEE)-type downflow radiant-only gasifier followed by a quench section. A two-stage water gas shift (WGS) reaction is considered for conversion of about 96 mol% of CO to CO2. A two-stage acid gas removal (AGR) process based on a physical solvent is simulated for selective capture of H2S and CO2. The clean syngas is sent to a gas turbine (GT) followed by a heat recovery steam generator (HRSG). The steady state results are validated with data from a commercial gasifier. A 5 % ramp increase in the flowrate of coal is introduced to study the system dynamics. To control the conversion of CO at a desired level in the WGS reactors, the steam/CO ratio is manipulated. This strategy is found to be efficient for this operating condition. In the absence of an efficient control strategy in the AGR process, the environmental emissions exceeded the limits by a great extent.

Bhattacharyya, D.; Turton, R.; Zitney, S.

2009-01-01T23:59:59.000Z

382

A comparison of crystalline and molten structures of zirconolite (CaZrTi?O?), a potential plutonium wasteform medium, by molecular dynamics simulation and topological analysis  

E-Print Network (OSTI)

Molecular dynamics simulations of the ceramic compound zirconolite (CaZrTi?O?), a potential crystalline wasteform host for plutonium, were carried out for ideal and experimental crystalline forms and a simulated molten ...

Rich, Sarah Celeste

2008-01-01T23:59:59.000Z

383

Evaluation of a CCSM3 Simulation with a Finite Volume Dynamical Core for the Atmosphere at 1° Latitude × 1.25° Longitude Resolution  

Science Conference Proceedings (OSTI)

A simulation of the present-day climate by the Community Climate System Model version 3 (CCSM3) that uses a Finite Volume (FV) numerical method for solving the equations governing the atmospheric dynamics is presented. The simulation is compared ...

G. Bala; R. B. Rood; A. Mirin; J. McClean; Krishna Achutarao; D. Bader; P. Gleckler; R. Neale; P. Rasch

2008-04-01T23:59:59.000Z

384

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

Australia A B C D L P S Tool Applications Free Recently Updated AWDABPT building temperature simulation, thermal performance Software has been updated. BEAVER energy simulation,...

385

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

Netherlands B H Tool Applications Free Recently Updated Building Energy Modelling and Simulation: Self-Learning Modules energy simulation, buildings, courseware, self-learning,...

386

Dynamical response of the "GGG" rotor to test the Equivalence Principle: theory, simulation and experiment. Part I: the normal modes  

E-Print Network (OSTI)

Recent theoretical work suggests that violation of the Equivalence Principle might be revealed in a measurement of the fractional differential acceleration $\\eta$ between two test bodies -of different composition, falling in the gravitational field of a source mass- if the measurement is made to the level of $\\eta\\simeq 10^{-13}$ or better. This being within the reach of ground based experiments, gives them a new impetus. However, while slowly rotating torsion balances in ground laboratories are close to reaching this level, only an experiment performed in low orbit around the Earth is likely to provide a much better accuracy. We report on the progress made with the "Galileo Galilei on the Ground" (GGG) experiment, which aims to compete with torsion balances using an instrument design also capable of being converted into a much higher sensitivity space test. In the present and following paper (Part I and Part II), we demonstrate that the dynamical response of the GGG differential accelerometer set into supercritical rotation -in particular its normal modes (Part I) and rejection of common mode effects (Part II)- can be predicted by means of a simple but effective model that embodies all the relevant physics. Analytical solutions are obtained under special limits, which provide the theoretical understanding. A simulation environment is set up, obtaining quantitative agreement with the available experimental data on the frequencies of the normal modes, and on the whirling behavior. This is a needed and reliable tool for controlling and separating perturbative effects from the expected signal, as well as for planning the optimization of the apparatus.

G. L. Comandi; M. L. Chiofalo; R. Toncelli; D. Bramanti; E. Polacco; A. M. Nobili

2006-01-18T23:59:59.000Z

387

The use of dynamic adaptive chemistry in combustion simulation of gasoline surrogate fuels  

Science Conference Proceedings (OSTI)

A computationally efficient dynamic adaptive chemistry (DAC) scheme is described that permits on-the-fly mechanism reduction during reactive flow calculations. The scheme reduces a globally valid full mechanism to a locally, instantaneously applicable smaller mechanism. Previously we demonstrated its applicability to homogeneous charge compression ignition (HCCI) problems with n-heptane [L. Liang, J.G. Stevens, J.T. Farrell, Proc. Combust. Inst. 32 (2009) 527-534]. In this work we demonstrate the broader utility of the DAC scheme through the simulation of HCCI and shock tube ignition delay times (IDT) for three gasoline surrogates, including two- and three-component blends of primary reference fuels (PRF) and toluene reference fuels (TRF). Both a detailed 1099-species mechanism and a skeletal 150-species mechanism are investigated as the full mechanism to explore the impact of fuel complexity on the DAC scheme. For all conditions studied, pressure and key species profiles calculated using the DAC scheme are in excellent agreement with the results obtained using the full mechanisms. For the HCCI calculations using the 1099- and 150-species mechanisms, the DAC scheme achieves 70- and 15-fold CPU time reductions, respectively. For the IDT problems, corresponding speed-up factors of 10 and two are obtained. Practical guidance is provided for choosing the search-initiating species set, selecting the threshold, and implementing the DAC scheme in a computational fluid dynamics (CFD) framework. (author)

Liang, Long; Raman, Sumathy; Farrell, John T. [Corporate Strategic Research Laboratories, ExxonMobil Research and Engineering Company, 1545 Route 22 East, Annandale, NJ 08801 (United States); Stevens, John G. [Corporate Strategic Research Laboratories, ExxonMobil Research and Engineering Company, 1545 Route 22 East, Annandale, NJ 08801 (United States); Department of Mathematical Sciences, Montclair State University, Montclair, NJ 07043 (United States)

2009-07-15T23:59:59.000Z

388

Experiment and Simulation of Dynamic Voltage Regulation in Multiple Distributed Energy Resources Systems  

Science Conference Proceedings (OSTI)

Distributed energy (DE) resources are power sources located near load centers and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide reactive power (along with active power) locally for dynamic voltage regulation. In this paper, a synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Developed voltage control schemes for the inverter and the synchronous condenser are presented. Experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously although the dynamic response of the inverter is much faster than the synchronous condenser. In a system with multiple DEs performing local voltage regulation, the interaction between the DEs is studied. The simulation results show the relationship between the voltages in the system and the reactive power required for the voltage regulation. Also, integrated voltage regulation (multiple DEs performing voltage regulation) can increase the voltage regulation capability of DEs and reduce the capital and operating costs.

Xu, Yan [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL; Rizy, D Tom [ORNL

2007-01-01T23:59:59.000Z

389

Molecular Dynamics Simulation of Tri-n-Butyl-Phophate Liquid: A Force Field Comparative Study  

SciTech Connect

Molecular dynamics (MD) simulations were conducted to compare the performance of four force fields in predicting thermophysical properties of tri-n-butyl-phosphate (TBP) in the liquid phase. The intramolecular force parameters used were from the Assisted Model Building with Energy Refinement (AMBER) force field model. The van der Waals parameters were based on either the AMBER or the Optimized Potential for Liquid Simulation (OPLS) force fields. The atomic partial charges were either assigned by performing quantum chemistry calculations or utilized previously published data, and were scaled to approximate the average experimental value of the electric dipole moment. Canonical ensemble computations based on the aforementioned parameters were performed near the atmospheric pressure and temperature to obtain the electric dipole moment, mass density, and self-diffusion coefficient. In addition, the microscopic structure of the liquid was characterized via pair correlation functions between selected atoms. It has been demonstrated that the electric dipole moment can be approximated within 1% of the average experimental value by virtue of scaled atomic partial charges. The liquid mass density can be predicted within 0.5-1% of its experimentally determined value when using the corresponding charge scaling. However, in all cases the predicted self- diffusion coefficient is significantly smaller than a commonly quoted experimental measurement; this result is qualified by the fact that the uncertainty of the experimental value was not available.

Cui, Shengting [ORNL; de Almeida, Valmor F [ORNL; Hay, Benjamin [ORNL; Ye, Xianggui [ORNL; Khomami, Bamin [ORNL

2012-01-01T23:59:59.000Z

390

Dynamic Modeling and Simulation Based Analysis of an Ammonia Borane (AB) Reactor System for Hydrogen Storage  

DOE Green Energy (OSTI)

Research on ammonia borane (AB, NH3BH3) has shown it to be a promising material for chemical hydrogen storage in PEM fuel cell applications. AB was selected by DOE’s Hydrogen Storage Engineering Center of Excellence (HSECoE) as the initial chemical hydride of study because of its high hydrogen storage capacity (up to 19.6% by weight for the release of three molar equivalents of hydrogen gas) and its stability under typical ambient conditions. A model of a bead reactor system which includes feed and product tanks, hot and cold augers, a ballast tank/reactor, a H2 burner and a radiator was developed to study AB system performance in an automotive application and estimate the energy, mass, and volume requirements for this off-board regenerable hydrogen storage material. Preliminary system simulation results for a start-up case and for a transient drive cycle indicate appropriate trends in the reactor system dynamics. A new controller was developed and validated in simulation for a couple of H2 demand cases.

Devarakonda, Maruthi N.; Holladay, Jamelyn D.; Brooks, Kriston P.; Rassat, Scot D.; Herling, Darrell R.

2010-10-02T23:59:59.000Z

391

Non-Fourier heat conduction in a single-walled carbon nanotube: Classical molecular dynamics simulations  

SciTech Connect

Nonstationary heat conduction in a single-walled carbon nanotube was investigated by applying a local heat pulse with duration of subpicoseconds. The investigation was based on classical molecular dynamics simulations, where the heat pulse was generated as coherent fluctuations by connecting a thermostat to the local cell for a short duration. The heat conduction through the nanotube was observed in terms of spatiotemporal temperature profiles. Results of the simulations exhibit non-Fourier heat conduction where a distinct amount of heat is transported in a wavelike form. The geometry of carbon nanotubes allows us to observe such a phenomenon in the actual scale of the material. The resulting spatiotemporal profile was compared with the available macroscopic equations, the so-called non-Fourier heat conduction equations, in order to investigate the applicability of the phenomenological models to a quasi-one-dimensional system. The conventional hyperbolic diffusion equation fails to predict the heat conduction due to the lack of local diffusion. It is shown that this can be remedied by adopting a model with dual relaxation time. Further modal analyses using wavelet transformations reveal a significant contribution of the optical phonon modes to the observed wavelike heat conduction. The result suggests that, in carbon nanotubes with finite length where the long-wavelength acoustic phonons behave ballistically, even optical phonons can play a major role in the non-Fourier heat conduction.

Shiomi, Junichiro; Maruyama, Shigeo [Department of Mechanical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2006-05-15T23:59:59.000Z

392

Building Energy Software Tools Directory: TAS  

NLE Websites -- All DOE Office Websites (Extended Search)

TAS TAS TAS logo Tas is an industry-leading building modelling and simulation tool. Capable of performing fast dynamic thermal simulation for the worldÂ’s largest and most complex buildings, Tas allows designers to accurately predict energy consumption, CO2 emissions, operating costs and occupant comfort. Tas is a complete solution for the thermal simulation of a building and a comprehensive tool for modelling plant and systems using itÂ’s graphical and component based analysis. Tas is a powerful design tool in the optimisation of a buildings environmental, energy and comfort performance. Tas can import gbXML, INP, and IDF files from 3rd party programs. There are also customisable report generation facilities. The Tas suite allows full automation available through visual basic. This

393

NREL: Wind Research - Offshore Design Tools and Methods  

NLE Websites -- All DOE Office Websites (Extended Search)

Design Tools and Methods Design Tools and Methods Graphic of a modular depiction of the FAST tool, which includes aerodynamics, hydrodynamics, control and electrical system dynamics, and structural dynamics modules. NREL's CAE Tool, FAST, and its Sub-Modules Illustration of wind turbines in various environments including land-based, shallow water (0-30m), transitional depth (30-60m), and deep water floating (greater than 60m). FAST has the capability of modeling a wide range of offshore wind system configurations including shallow water, transitional depth, and floating systems. With DOE's support, NREL has developed and maintains a robust, open-source, modular computer-aided engineering (CAE) tool, known as FAST. It has state-of-the-art capabilities for full dynamic system simulation over a

394

WiMsh: a simple and efficient tool for simulating IEEE 802.16 wireless mesh networks in ns-2  

Science Conference Proceedings (OSTI)

Wireless mesh networks (WMNs) are two-tier wireless multihop networks. The top tier is made of wireless routers, which provide access to the wireless clients in the bottom tier. One technology for enabling multi-hop communication in the top tier is IEEE ... Keywords: IEEE 802.16, network simulator 2, simulation, wireless mesh networks

Claudio Cicconetti; Ian F. Akyildiz; Luciano Lenzini

2009-03-01T23:59:59.000Z

395

Numerical simulation of four-field extended magnetohydrodynamics in dynamically adaptive curvilinear coordinates via Newton-Krylov-Schwarz  

Science Conference Proceedings (OSTI)

Numerical simulations of the four-field extended magnetohydrodynamics (MHD) equations with hyper-resistivity terms present a difficult challenge because of demanding spatial resolution requirements. A time-dependent sequence of r-refinement adaptive ... Keywords: Dynamically adaptive grid, Equidistribution principle, MHD, Magnetic reconnection, Monge-Ampère equation, Monge-Kantorovich optimization, NKS, Structured grid, r-Refinement

Xuefei Yuan; Stephen C. Jardin; David E. Keyes

2012-07-01T23:59:59.000Z

396

Simulation of shock-induced melting of Ni using molecular dynamics coupled to a two-temperature model  

E-Print Network (OSTI)

Simulation of shock-induced melting of Ni using molecular dynamics coupled to a two-temperature and electron-phonon coupling, Pmelt and Tmelt change. For a given pressure, the temperature behind the shock conduction and electron-phonon coupling. The decrease in the temperature behind the shock front is enhanced

Zhigilei, Leonid V.

397

Molecular Dynamics Simulation of Phase-Change of Water inside a SWNT Shigeo Maruyama, Tatsuto Kimura and Yasuhiro Igarashi  

E-Print Network (OSTI)

, Bunkyo-ku, Tokyo 113-8656, Japan The phase change of liquid water to ice crystal inside a singleMolecular Dynamics Simulation of Phase-Change of Water inside a SWNT Shigeo Maruyama, Tatsuto, the carbon atoms were cooled at the constant heat-removal rate. The phase change phenomena with various rates

Maruyama, Shigeo

398

Modular Modeling System (MMS): A Code for the Dynamic Simulation of Fossil and Nuclear Power Plants, Volume 2: Programmer's Manual  

Science Conference Proceedings (OSTI)

Now complete and fully documented, the MMS code is available for the dynamic simulation of both fossil-fired and nuclear power plants. The broad range of applications, from troubleshooting new designs to analysis of startup tests, has made this easy-to use code a utility standard since its first-stage release in 1983.

1987-05-01T23:59:59.000Z

399

Modular Modeling System (MMS): A Code for the Dynamic Simulation of Fossil and Nuclear Power Plants, Volume 1: Theory Manual  

Science Conference Proceedings (OSTI)

Now complete and fully documented, the MMS code is available for the dynamic simulation of both fossil-fired and nuclear power plants. The broad range of applications, from troubleshooting new designs to analysis of startup tests, has made this easy-to use code a utility standard since its first-stage release in 1983.

1987-04-01T23:59:59.000Z

400

Benchmark of the IMPACT Code for High Intensity Beam Dynamics Simulation  

E-Print Network (OSTI)

of Beam Dynamics in the SNS Linac," Nuclear Instruments andto study beam dynamics in the SNS linac, the J-PARC linac

Qiang, J.; Ryne, R.D.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Modified Nose-Hoover thermostat for solid state for constant temperature molecular dynamics simulation  

SciTech Connect

Nose-Hoover (NH) thermostat methods incorporated with molecular dynamics (MD) simulation have been widely used to simulate the instantaneous system temperature and feedback energy in a canonical ensemble. The method simply relates the kinetic energy to the system temperature via the particles' momenta based on the ideal gas law. However, when used in a tightly bound system such as solids, the method may suffer from deriving a lower system temperature and potentially inducing early breaking of atomic bonds at relatively high temperature due to the neglect of the effect of the potential energy of atoms based on solid state physics. In this paper, a modified NH thermostat method is proposed for solid system. The method takes into account the contribution of phonons by virtue of the vibrational energy of lattice and the zero-point energy, derived based on the Debye theory. Proof of the equivalence of the method and the canonical ensemble is first made. The modified NH thermostat is tested on different gold nanocrystals to characterize their melting point and constant volume specific heat, and also their size and temperature dependence. Results show that the modified NH method can give much more comparable results to both the literature experimental and theoretical data than the standard NH. Most importantly, the present model is the only one, among the six thermostat algorithms under comparison, that can accurately reproduce the experimental data and also the T{sup 3}-law at temperature below the Debye temperature, where the specific heat of a solid at constant volume is proportional to the cube of temperature.

Chen, Wen-Hwa, E-mail: whchen@pme.nthu.edu.tw [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); National Applied Research Laboratories, Taipei 10622, Taiwan, ROC (China); Wu, Chun-Hung [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Cheng, Hsien-Chie [Department of Aerospace and Systems Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

2011-07-10T23:59:59.000Z

402

Development of a Modelling and Simulation Method Comparison and Selection Framework for Health Services Management  

E-Print Network (OSTI)

were car- ried out with local and national level health care man- agers to investigate their responses in depth. At the end of the project (after iterative revision of the tool), the national level health care manager at the NHS Institute of Innovation... and modelling in aerospace and the military Distributed Simulation, Discrete Event Simulation, System Dynamics, Real Time Simulation, Monte Carlo Simulation, Agent Based Simulation, War Gaming, Hybrid Simulation, Inverse Simulation, Petri-net, Markovian Model...

Jun, Gyuchan T; Morris, Zoe; Eldabi, Tillal; Harper, Paul; Naseer, Aisha; Patel, Brijesh; Clarkson, John P

2011-05-19T23:59:59.000Z

403

Development Plan for the Fuel Cycle Simulator  

Science Conference Proceedings (OSTI)

The Fuel Cycle Simulator (FCS) project was initiated late in FY-10 as the activity to develop a next generation fuel cycle dynamic analysis tool for achieving the Systems Analysis Campaign 'Grand Challenge.' This challenge, as documented in the Campaign Implementation Plan, is to: 'Develop a fuel cycle simulator as part of a suite of tools to support decision-making, communication, and education, that synthesizes and visually explains the multiple attributes of potential fuel cycles.'

Brent Dixon

2011-09-01T23:59:59.000Z

404

Comment on “Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop”  

SciTech Connect

In this paper, the authors comment on several mistakes made in a journal paper "Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop" published on Environmental Scienece & Technology, based on field measurements from Great Lakes Bioenergy Research Center, Carbon Sequestration in Terrestrial Ecosystems, and published literature. Our comment has led to the development of another version of SWAT to include better process based description of radiation use efficiency and root-shoot growth.

Zhang, Xuesong; Izaurralde, Roberto C.; Arnold, J. G.; Sammons, N. B.; Manowitz, David H.; Thomson, Allison M.; Williams, J.R.

2011-07-01T23:59:59.000Z

405

A comparative study of Lotka-Volterra and system dynamics models for simulation of technology industry dynamics  

E-Print Network (OSTI)

Scholars have developed a range of qualitative and quantitative models for generalizing the dynamics of technological innovation and identifying patterns of competition between rivals. This thesis compares two predominant ...

Ünver, Hakk? Özgür

2008-01-01T23:59:59.000Z

406

Molecular dynamics simulation of montmorillonite and mechanical and thermodynamic properties calculations  

E-Print Network (OSTI)

Nanocomposites refer to the materials in which the defining characteristic size of inclusions is in the order of 10-100nm. There are several types of nanoparticle inclusions with different structures: metal clusters, fullerenes particles and molybdenum selenide, Our research focus is on polymer nanocomposites with inorganic clay particles as inclusions, in particular we used sodium montmorillonite polymer nanocomposite. In our study, modeling and simulations of sodium montmorillonite (Na+-MMT) is currently being investigated as an inorganic nanocomposite material. Na+-MMT clay consists of platelets, one nanometer thick with large lateral dimensions, which can be used to achieve efficient reinforcement of polymer matrices. This nanocomposite has different applications such as a binder of animal feed, a plasticizing agent in cement, brick and ceramic, and a thickener and stabilizer of latex and rubber adhesives. In this study, sodium montmorillonite called Na+-MMT structure is built with the bulk system and the layered system which includes from 1 to 12 layers by using Crystal Builder of Cerius2. An isothermal and isobaric ensemble is used for calculation of thermodynamic properties such as specific heat capacities and isothermal expansion coefficients of Na+-MMT. A canonical ensemble which holds a fixed temperature, volume and number of molecules is used for defining exfoliation kinetics of layered structures and surface formation energies for Na+-MMT layered structures are calculated by using a canonical ensemble. Mechanical properties are used to help characterize and identify the Na+-MMT structure. Several elastic properties such as compliance and stiffness matrices, Young's, shear, and bulk modulus, volume compressibility, Poisson's ratios, Lamé constants, and velocities of sound are calculated in specified directions. Another calculation method is the Vienna Ab-initio Simulation Package (VASP). VASP is a complex package for performing ab-initio quantum-mechanical calculations and molecular dynamic (MD) simulations using pseudopotentials and a plane wave basis set. Cut off energy is optimized for the unit cell of Na+-MMT by using different cut off energy values. Experimental and theoretical cell parameters are compared by using cell shape and volume optimization and root mean square (RMS) coordinate difference is calculated for variation of cell parameters. Cell shape and volume optimization are done for calculating optimum expansion or compression constant.

Atilhan, Selma

2007-05-01T23:59:59.000Z

407

Computational fluid dynamics (CFD) simulations of aerosol in a u-shaped steam generator tube  

E-Print Network (OSTI)

To quantify primary side aerosol retention, an Eulerian/Lagrangian approach was used to investigate aerosol transport in a compressible, turbulent, adiabatic, internal, wall-bounded flow. The ARTIST experimental project (Phase I) served as the physical model replicated for numerical simulation. Realizable k-? and standard k-? turbulence models were selected from the computational fluid dynamics (CFD) code, FLUENT, to provide the Eulerian description of the gaseous phase. Flow field simulation results exhibited: a) onset of weak secondary flow accelerated at bend entrance towards the inner wall; b) flow separation zone development on the convex wall that persisted from the point of onset; c) centrifugal force concentrated high velocity flow in the direction of the concave wall; d) formation of vortices throughout the flow domain resulted from rotational (Dean-type) flow; e) weakened secondary flow assisted the formation of twin vortices in the outflow cross section; and f) perturbations induced by the bend influenced flow recovery several pipe diameters upstream of the bend. These observations were consistent with those of previous investigators. The Lagrangian discrete random walk model, with and without turbulent dispersion, simulated the dispersed phase behavior, incorrectly. Accurate deposition predictions in wall-bounded flow require modification of the Eddy Impaction Model (EIM). Thus, to circumvent shortcomings of the EIM, the Lagrangian time scale was changed to a wall function and the root-mean-square (RMS) fluctuating velocities were modified to account for the strong anisotropic nature of flow in the immediate vicinity of the wall (boundary layer). Subsequent computed trajectories suggest a precision that ranges from 0.1% to 0.7%, statistical sampling error. The aerodynamic mass median diameter (AMMD) at the inlet (5.5 ?m) was consistent with the ARTIST experimental findings. The geometric standard deviation (GSD) varied depending on the scenario evaluated but ranged from 1.61 to 3.2. At the outlet, the computed AMMD (1.9 ?m) had GSD between 1.12 and 2.76. Decontamination factors (DF), computed based on deposition from trajectory calculations, were just over 3.5 for the bend and 4.4 at the outlet. Computed DFs were consistent with expert elicitation cited in NUREG-1150 for aerosol retention in steam generators.

Longmire, Pamela

2007-05-01T23:59:59.000Z

408

Predicting Long-Term Performance of Photovoltaic Arrays Using Short-Term Test Data and an Annual Simulation Tool: Preprint (Revised)  

DOE Green Energy (OSTI)

We present a method of analysis for predicting annual performance of an in-situ photovoltaic (PV) array using short-term test data and an annual simulation tool. The method involves fitting data from a family of I-V curves (depicting current versus voltage) taken from a short-term test (1 to 3 day) of a PV array to a set of polynomial functions. These functions are used to predict the array's behaviour under a wide range of temperatures and irradiances. TRNSYS, driven by TMY2 weather data, is used to simulate the array's behaviour under typical weather conditions. We demonstrate this method by using results from a nominal 630-W array.

Barker, G.; Norton, P.

2003-11-01T23:59:59.000Z

409

Molecular dynamics simulations of H{sub 2} adsorption in tetramethyl ammonium lithium phthalocyanine crystalline structures.  

DOE Green Energy (OSTI)

Tetramethyl ammonium lithium phthalocyanine is explored as a potential material for storage of molecular hydrogen. Density functional theory calculations are used to investigate the molecular structure and the dimer conformation. Additional scans performed to determine the interactions of a H{sub 2} molecule located at various distances from the molecular sites are used to generate a simple force field including dipole-induced-dipole interactions. This force field is employed in molecular dynamics simulations to calculate adsorption isotherms at various pressures. The regions of strongest adsorption are quantified as functions of temperature, pressure, and separation between molecules in the adsorbent phase, and compared to the regions of strongest binding energy as given by the proposed force field. It is found that the total adsorption could not be predicted only from the spatial distribution of the strongest binding energies; the available volume is the other contributing factor even if the volume includes regions of much lower binding energy. The results suggest that the complex anion is primarily involved in the adsorption process with molecular hydrogen, whereas the cation serves to provide access for hydrogen adsorption in both sides of the anion molecular plane, and spacing between the planes.

Lamonte, K.; Gomez Gualdron, D.; Scanlon, L. G.; Sandi, G.; Feld, W.; Balbuena, P. B.; Chemical Sciences and Engineering Division; Texas A& M Univ.; Wright-Patterson Air Force Base; Wright State Univ.

2008-11-01T23:59:59.000Z

410

Molecular-dynamics simulation of clustering processes in sea-ice floes  

E-Print Network (OSTI)

In seasonally ice-covered seas and along the margins of perennial ice pack, i.e. in regions with medium ice concentrations, the ice cover typically consists of separate floes interacting with each other by inelastic collisions. In this paper, hitherto unexplored analogies between this type of ice cover and two-dimensional granular gases are used to formulate a model of ice dynamics at the floe level. The model consists of: (i) momentum equations for floe motion between collisions, formulated in the form of a Stokes-flow problem, with floe-size dependent time constant and equilibrium velocity, and (ii) hard-disk collision model. The numerical algorithm developed is suitable for simulating particle-laden flow of $N$ disk-shaped floes with arbitrary size distribution. The model is applied to study clustering phenomena in sea ice with power-law floe-size distribution. In particular, the influence of the average ice concentration $\\bar{A}$ on the formation and characteristics of clusters is analyzed in detail. The...

Herman, Agnieszka

2011-01-01T23:59:59.000Z

411

Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.  

Science Conference Proceedings (OSTI)

Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

Meixner, Tom (University of Arizona, Tucson, AZ); Tidwell, Vincent Carroll; Oelsner, Gretchen (University of Arizona, Tucson, AZ); Brooks, Paul (University of Arizona, Tucson, AZ); Roach, Jesse D.

2008-08-01T23:59:59.000Z

412

Project Description This project is intended to provide the powertrain and vehicle modeling and simulation tools needed  

E-Print Network (OSTI)

and compared with the more standard parallel and Prius planetary arrangements in terms of system efficiency and electric operation of the actuators in the CVT. Modeling of the Prius planetary and Civic single in the drivelines and to validate the simulation results for the hybrids, especially the PHEVs. 2004 Prius PHEV, 3 k

California at Davis, University of

413

Agni: Coupling Model Analysis Tools and High-Performance Subsurface Flow and Transport Simulators for Risk and Performance Assessments  

Science Conference Proceedings (OSTI)

Agni is open source /community /multi platform framework for model-based analyses (SA, UQ, PE, RA, DS). Agni can be applied independently from other Advanced Simulation Capability for Environmental Management (ASCEM) modules. Agni will be available as Mercurial repository (hg clone https://akuna.labworks.org/hg/Platform) including source code, manual, test and verification examples.

Vesselinov, Velimir V. [Los Alamos National Laboratory; Pau, George [LBNL; Finsterle, Stefan [LBNL

2012-06-28T23:59:59.000Z

414

Development and simulation of a cylindrical cusped-field thruster and a diagnostics tool for plasma-materials interactions  

E-Print Network (OSTI)

A low power, Hall-effect type plasma thruster known as the MIT-Cylindrical Cusped- Field Thruster (MIT-CCFT) has been developed and simulated using a fully-kinetic plasma model, the Plasma Thruster particle-in-cell (PTpic) ...

Pang, Anthony

2013-01-01T23:59:59.000Z

415

Force-field development and molecular dynamics simulations of ferrocene-peptide conjugates as a scaffold for hydrogenase mimics.  

Science Conference Proceedings (OSTI)

The increasing importance of hydrogenase enzymes in the new energy research field has led us to examine the structure and dynamics of potential hydrogenase mimics, based on a ferrocene-peptide scaffold, using molecular dynamics (MD) simulations. To enable this MD study, a molecular mechanics force field for ferrocene-bearing peptides was developed and implemented in the CHARMM simulation package, thus extending the usefulness of the package into peptide-bioorganometallic chemistry. Using the automated frequency-matching method (AFMM), optimized intramolecular force-field parameters were generated through quantum chemical reference normal modes. The partial charges for ferrocene were derived by fitting point charges to quantum-chemically computed electrostatic potentials. The force field was tested against experimental X-ray crystal structures of dipeptide derivatives of ferrocene-1,1{prime}-dicarboxylic acid. The calculations reproduce accurately the molecular geometries, including the characteristic C2-symmetrical intramolecular hydrogen-bonding pattern, that were stable over 0.1{micro}s MD simulations. The crystal packing properties of ferrocene-1-(D)alanine-(D)proline{prime}-1-(D)alanine-(D)proline were also accurately reproduced. The lattice parameters of this crystal were conserved during a 0.1 s MD simulation and match the experimental values almost exactly. Simulations of the peptides in dichloromethane are also in good agreement with experimental NMR and circular dichroism (CD) data in solution. The developed force field was used to perform MD simulations on novel, as yet unsynthesized peptide fragments that surround the active site of [Ni-Fe] hydrogenase. The results of this simulation lead us to propose an improved design for synthetic peptide-based hydrogenase models. The presented MD simulation results of metallocenes thereby provide a convincing validation of our proposal to use ferrocene-peptides as minimal enzyme mimics.

De Hatten, Xavier [University of Bordeaux; Cournia, Zoe [Yale University; Smith, Jeremy C [ORNL; Metzler-Nolte, Nils [University of Bochum, Germany

2007-08-01T23:59:59.000Z

416

Force-field development and molecular dynamics simulations of ferrocene-peptide conjugates as a scaffold for hydrogenase mimics  

Science Conference Proceedings (OSTI)

The increasing importance of hydrogenase enzymes in the new energy research field has led us to examine the structure and dynamics of potential hydrogenase mimics, based on a ferrocene-peptide scaffold, using molecular dynamics (MD) simulations. To enable this MD study, a molecular mechanics force field for ferrocene-bearing peptides was developed and implemented in the CHARMM simulation package, thus extending the usefulness of the package into peptide-bioorganometallic chemistry. Using the automated frequency-matching method (AFMM), optimized intramolecular force-field parameters were generated through quantum chemical reference normal modes. The partial charges for ferrocene were derived by fitting point charges to quantum-chemically computed electrostatic potentials. The force field was tested against experimental X-ray crystal structures of dipeptide derivatives of ferrocene-1,1'-dicarboxylic acid. The calculations reproduce accurately the molecular geometries, including the characteristic C{sub 2}-symmetrical intramolecular hydrogen-bonding pattern, that were stable over 0.1 {micro}s MD simulations. The crystal packing properties of ferrocene-1-(D)alanine-(D)proline-1'-(D)alanine-(D)proline were also accurately reproduced. The lattice parameters of this crystal were conserved during a 0.1 {micro}s MD simulation and match the experimental values almost exactly. Simulations of the peptides in dichloromethane are also in good agreement with experimental NMR and circular dichroism (CD) data in solution. The developed force field was used to perform MD simulations on novel, as yet unsynthesized peptide fragments that surround the active site of [Ni-Fe] hydrogenase. The results of this simulation lead us to propose an improved design for synthetic peptide-based hydrogenase models. The presented MD simulation results of metallocenes thereby provide a convincing validation of our proposal to use ferrocene-peptides as minimal enzyme mimics.

De Hatten, Xavier [University of Bordeaux; Cournia, Zoe [Yale University; Smith, Jeremy C [ORNL; Huc, I [University of Bochum, Germany; Metzler-Nolte, Nils [University of Bochum, Germany

2007-08-01T23:59:59.000Z

417

Adaptive-boost molecular dynamics simulation of carbon diffusion in iron  

E-Print Network (OSTI)

We have developed an accelerated molecular dynamics (MD) method to model atomic-scale rare events. In this method, a smooth histogram of collective variables is first estimated by canonical ensemble molecular dynamics ...

Ishii, Akio

418

Influence of Electrification on Microphysical and Dynamical Processes in a Numerically Simulated Thunderstorm  

Science Conference Proceedings (OSTI)

A new three-dimensional dynamics and electrification coupled model is developed to investigate the influence of electrification on microphysical and dynamical processes in thunderstorms. This model includes a four-class ice microphysics scheme, ...

Anping Sun; Hye-Yeong Chun; Jong-Jin Baik; Muhong Yan

2002-11-01T23:59:59.000Z

419

Improving Health Care Management Through the Use of Dynamic Simulation Modeling and Health Information Systems  

Science Conference Proceedings (OSTI)

To better understand the performance of hospital operations in response to IT-enabled improvement, this paper reports the results of a system dynamics model designed to improve core medical processes. Utilizing system dynamics modeling and emerging Health ... Keywords: Health Information Systems, Heath Care, Hospital Management, Process Improvement, System Dynamics

Daniel Goldsmith; Michael Siegel

2012-01-01T23:59:59.000Z

420

Dissipative particle dynamics simulation of fluid motion through an unsaturated fracture and fracture junction  

Science Conference Proceedings (OSTI)

Multiphase fluid motion in unsaturated fractures and fracture networks involves complicated fluid dynamics, which is difficult to model using grid-based continuum methods. In this paper, the application of dissipative particle dynamics (DPD), a relatively ... Keywords: Dissipative particle dynamics (DPD), Fracture, Fracture flow, Smoothed particle hydrodynamics (SPH), Weight functions

Moubin Liu; Paul Meakin; Hai Huang

2007-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Building Energy Software Tools Directory: NewQUICK  

NLE Websites -- All DOE Office Websites (Extended Search)

NewQUICK NewQUICK NewQUICK logo. Thermal design and simulation tool capable of calculating loads and energy consumption. NewQuick can predict hourly air temperatures and relative humidities, which makes it a valuable tool in the passive design of building envelopes. Complete load and energy analysis of a building can further be executed in order to design an efficient air-conditioning system (HVAC). The simulation tool executes dynamic thermal calculations for realistic 'real life' temperature and load predictions. The building model integrates natural ventilation, internal load (convective and radiative), occupant load and evaporative cooling models. The simulation tool includes the modelling of external shading devices, interior mass, direct solar heat gains and ground contact surfaces.

422

Advanced beam-dynamics simulation tools for the RIA driver linac, Part I: Low energy beam transport and radiofrequency quadrupole  

E-Print Network (OSTI)

version of PARMTEQ on the NERSC computing facility, readyimplementation will be at NERSC (National Energy Researchcomputer version, later at NERSC. Modify space-charge for

2003-01-01T23:59:59.000Z

423

The Interaction of Radiative and Dynamical Processes during a Simulated Sudden Stratospheric Warming  

Science Conference Proceedings (OSTI)

An analysis of a spontaneous sudden stratospheric warming that occurred during a 2-year integration of the Langley Research Center Atmospheric Simulation Model is presented. The simulated warming resembles observed “wave 1&rdquo warmings in the ...

R. B. Pierce; W. T. Blackshear; W. L. Grose; R. E. Turner; T. D. Fairlie

1993-12-01T23:59:59.000Z

424

System implementation issues of dynamic discrete disaster decision simulation system (D4S2): phase I  

Science Conference Proceedings (OSTI)

Simulation has many advantages in modeling complex systems to facilitate decision making. In this research, an integrated computer system will be developed which incorporates an agent-based discrete event simulator, a geographic information system, a ...

Shengnan Wu; Larry J. Shuman; Bopaya Bidanda; Matthew Kelley; Bryan Lawson; Ken Sochats; Carey D. Balaban

2007-12-01T23:59:59.000Z

425

Simulating past and future dynamics of natural ecosystems in the United States. Global Biogeochemical Cycles 17(2)1045  

E-Print Network (OSTI)

[1] Simulations of potential vegetation distribution, natural fire frequency, carbon pools, and fluxes are presented for two DGVMs (Dynamic Global Vegetation Models) from the second phase of the Vegetation/Ecosystem Modeling and Analysis Project. Results link vegetation dynamics to biogeochemical cycling for the conterminous United States. Two climate change scenarios were used: a moderately warm scenario from the Hadley Climate Centre and a warmer scenario from the Canadian Climate Center. Both include sulfate aerosols and assume a gradual CO2 increase. Both DGVMs simulate a reduction of southwestern desert areas, a westward expansion of eastern deciduous forests, and the expansion of forests in the western part of the Pacific Northwest and in north-central California. Both DGVMs predict an increase in total biomass burnt in the next century, with a more pronounced increase under the Canadian scenario. Under the Hadley scenario, both DGVMs simulate increases in total carbon stocks. Under the Canadian scenario, both DGVMs simulate a decrease in live vegetation carbon. We identify similarities in model behavior due to the climate forcing and explain differences by the different structure of the models and their different sensitivity to

Dominique Bachelet; Ronald P. Neilson; Thomas Hickler; Raymond J. Drapek; James M. Lenihan; Martin T. Sykes; Benjamin Smith; Stephen Sitch; Kirsten Thonicke

2003-01-01T23:59:59.000Z

426

DOI: 10.1017/S1464793103006419 Printed in the United Kingdom Vegetation dynamicssimulating responses to climatic change  

E-Print Network (OSTI)

A modelling approach to simulating vegetation dynamics is described, incorporating critical processes of carbon sequestration, growth, mortality and distribution. The model has been developed to investigate the responses of vegetation to environmental change, at time scales from days to centuries and from the local to the global scale. The model is outlined and subsequent tests, against independent data sources, are relatively successful, from the small scale to the global scale. Tests against eddy covariance observations of carbon exchange by vegetation indicated significant differences between measured and simulated net ecosystem production (NEP). NEP is the net of large fluxes due to gross primary production and respiration, which are not directly measured and so there is some uncertainty in explaining differences between observations and simulations. In addition it was noted that closer agreement of fluxes was achieved for natural, or long-lived managed vegetation than for recently managed vegetation. The discrepancies appear to be most closely related to respiratory carbon losses from the soil, but this area needs further exploration. The differences do not scale up to the global scale, where simulated and measured global net biome production were similar, indicating that fluxes measured at the managed observed sites are not typical globally. The model (the Sheffield Dynamic Global Vegetation Model, SDGVM) has been applied to contemporary

F. I. Woodward; M. R. Lomas

2003-01-01T23:59:59.000Z

427

Vehicle Technologies Office: Software Tools  

NLE Websites -- All DOE Office Websites (Extended Search)

Software Tools Software Tools Several software programs are available, either for free or for a nominal charge, that can assist fleet managers and technology developers in assessing the potential impacts of implementing new technologies. Autonomie Autonomie is a Plug-and-Play Powertrain and Vehicle Model Architecture and Development Environment to support the rapid evaluation of new powertrain/propulsion technologies for improving fuel economy through virtual design and analysis in a math-based simulation environment. Developed in partnership with General Motors, Autonomie is an open architecture to support the rapid integration and analysis of powertrain/propulsion systems and technologies for rapid technology sorting and evaluation of fuel economy improvement under dynamic/transient testing conditions. The capability to sort technologies rapidly in a virtual design environment results in faster improvements in real-world fuel consumption by reducing the time necessary to develop and bring new technologies onto our roads.

428

Numerical Simulation of Squeeze Film Dampers and Study of the Effect of Central Groove on the Dynamic Pressure Distribution  

E-Print Network (OSTI)

Squeeze film dampers are used in the high speed turbo machinery industry and aerospace industries as a means to reduce vibration amplitude, to provide damping, to improve dynamic stability of the rotor bearing system and to isolate structural components. The effects of cavitation included in previous studies were not effective. The effect of different design parameters were not studied thoroughly as experimental investigation of squeeze film dampers is very expensive. Few of them used numerical investigation but the methods they used are either time consuming or complicated. The present study investigated the feasibility of applying a steady state solver, which is computationally less expensive, for analyzing flow field inside the squeeze film dampers. The behavior of dynamic pressure profiles at different operating conditions, and the effect of a central groove on dynamic pressure profiles were also studied. Simulation results of a 3D case which is similar to the one experimentally studied by Delgado were used to establish if the moving reference frame (MRF) model in Fluent 12.1 can be used. A steady state solver in an absolute frame of reference was used to produce whirling motion of the rotor in this study. The inlet pressure of 31kpa and the whirling speed of 50 and 100Hz were used as boundary conditions. The mixture model with three percent dissolved air in lubricant is used to model multiphase flow. Singhal cavitation model is used to model cavitation. The simulations (50,000 iterations) were run until steady state solutions were reached. The results closely agreed with those obtained experimentally by San Andrés and Delgado. Numerical simulations of three-dimensional cases with an additional central groove on the squeeze film land were also performed to predict the effect of central groove on dynamic pressure profiles. Addition central groove reduces the pressures and forces generated by squeeze film damper.

Boppa, Praneetha

2011-08-01T23:59:59.000Z

429

Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines  

Science Conference Proceedings (OSTI)

This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

2011-10-01T23:59:59.000Z

430

On the Application of the Dynamic Smagorinsky Model to Large-Eddy Simulations of the Cloud-Topped Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

In this paper the dynamic Smagorinsky model originally developed for engineering flows is adapted for simulations of the cloud-topped atmospheric boundary layer in which an anelastic form of the governing equations is used. The adapted model ...

M. P. Kirkpatrick; A. S. Ackerman; D. E. Stevens; N. N. Mansour

2006-02-01T23:59:59.000Z

431

STRUCTURAL VALIDATION OF SYSTEM DYNAMICS AND AGENT-BASED SIMULATION MODELS  

E-Print Network (OSTI)

, population dynamics, energy systems, and urban planning. The usefulness of these models is predicated be opened in the bank; efficiency of the oil refinery can be enhanced under the recommended actions including global warming, population dynamics, energy systems, and urban planning simply defy a face

Tesfatsion, Leigh

432

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-Print Network (OSTI)

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic conditions with turbine models covering the range of scales important for wind plant dynamics to help address the impacts that upwind turbines have on turbines in their wake and give greater insight into overall wind

433

Modeling and simulation of new configuration of dynamic voltage restorer for power quality improvement  

Science Conference Proceedings (OSTI)

The dynamic voltage restorer (DVR) is a custom device that is used to maintain the voltage at the load terminals from various power quality problems from a disturbed incoming supply. In this paper, a novel control strategy is described for mitigation ... Keywords: custom device, dynamic voltage restorer (DVR), power quality, sags, sensitive loads, swells

Rosli Omar; Nasrudin Abdul Rahim

2011-04-01T23:59:59.000Z

434

Nonequilibrium molecular dynamics simulation of shear viscosity by a uniform momentum source-and-sink scheme  

Science Conference Proceedings (OSTI)

A uniform momentum source-and-sink scheme of nonequilibrium molecular dynamics (NEMD) is developed to calculate the shear viscosity of fluids in this paper. The uniform momentum source and sink are realized by momentum exchanges of individual atoms in ... Keywords: Molecular fluid, Nonequilibrium molecular dynamics, Shear viscosity, Uniform source-and-sink scheme

Bing-Yang Cao; Ruo-Yu Dong

2012-06-01T23:59:59.000Z

435

Dynamics of a Myoglobin Mutant Enzyme: 2D IR Vibrational Echo Experiments and Simulations  

E-Print Network (OSTI)

and A3 substates. The equilibrium protein dynamics for the two distinct substates of the Mb double for both of the substates are analyzed using the center line slope (CLS) method to obtain the frequency on the electronic ground state potential energy surface. Therefore, it is useful to study protein dynamics

Fayer, Michael D.

436

Molecular Dynamics Simulation of Solidification in Cu50Zr50 Alloy  

Science Conference Proceedings (OSTI)

Next, MD simulation of melting B2 phase surrounded by liquid was .... Thermochemical Models and Phase Equilibria of Urania Rare Earth Fluorite Phases.

437

Implied Dynamic Feedback of 3D IR Radiative Transfer on Simulated...  

NLE Websites -- All DOE Office Websites (Extended Search)

of 3D IR Radiative Transfer on Simulated Cloud Fields D. B. Mechem and Y. L. Kogan Cooperative Institute for Mesoscale Meteorological Studies University of Oklahoma Norman,...

438

Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation  

SciTech Connect

Utility Systems Efficiencies, Inc. was tasked by Lawrence Berkeley National Laboratory (LBNL) to conduct dynamic simulation studies of the three U.S. interconnections (Eastern, Western, and Texas). The simulations were prepared in support of LBNL's project for the Federal Energy Regulatory Commission to study frequency-response-related issues that must be addressed to operate the power system reliably with large amounts of variable renewable generation. The objective of the simulation studies of each interconnection was to assess the effects of different amounts of wind generation on frequency behavior of each interconnection following a sudden loss of generation. The scenarios created to study these effects considered an operating circumstance in which system load is at or close to its minimum. The event studied was the sudden loss of the largest amount of generation recorded within each interconnection. The simulations calculated the impact of this event on interconnection frequency for three levels of wind generation. In addition to varying the amount of wind generation, the simulations varied the amount of operating reserves between a high level representative of current operating practices and a low level representative of the minimum required by present operating rules.

Mackin, Peter; Daschmans, R.; Williams, B.; Haney, B.; Hung, R.; Ellis, J.

2010-12-20T23:59:59.000Z

439

Dynamic Simulation Studies of the Frequency Response of the Three U.S. Interconnections with Increased Wind Generation  

SciTech Connect

Utility Systems Efficiencies, Inc. was tasked by Lawrence Berkeley National Laboratory (LBNL) to conduct dynamic simulation studies of the three U.S. interconnections (Eastern, Western, and Texas). The simulations were prepared in support of LBNL's project for the Federal Energy Regulatory Commission to study frequency-response-related issues that must be addressed to operate the power system reliably with large amounts of variable renewable generation. The objective of the simulation studies of each interconnection was to assess the effects of different amounts of wind generation on frequency behavior of each interconnection following a sudden loss of generation. The scenarios created to study these effects considered an operating circumstance in which system load is at or close to its minimum. The event studied was the sudden loss of the largest amount of generation recorded within each interconnection. The simulations calculated the impact of this event on interconnection frequency for three levels of wind generation. In addition to varying the amount of wind generation, the simulations varied the amount of operating reserves between a high level representative of current operating practices and a low level representative of the minimum required by present operating rules.

Mackin, Peter; Daschmans, R.; Williams, B.; Haney, B.; Hung, R.; Ellis, J.

2010-12-20T23:59:59.000Z

440

A localised subgrid scale model for fluid dynamical simulations in astrophysics II: Application to type Ia supernovae  

E-Print Network (OSTI)

The dynamics of the explosive burning process is highly sensitive to the flame speed model in numerical simulations of type Ia supernovae. Based upon the hypothesis that the effective flame speed is determined by the unresolved turbulent velocity fluctuations, we employ a new subgrid scale model which includes a localised treatment of the energy transfer through the turbulence cascade in combination with semi-statistical closures for the dissipation and non-local transport of turbulence energy. In addition, subgrid scale buoyancy effects are included. In the limit of negligible energy transfer and transport, the dynamical model reduces to the Sharp-Wheeler relation. According to our findings, the Sharp-Wheeler relation is insuffcient to account for the complicated turbulent dynamics of flames in thermonuclear supernovae. The application of a co-moving grid technique enables us to achieve very high spatial resolution in the burning region. Turbulence is produced mostly at the flame surface and in the interior ash regions. Consequently, there is a pronounced anisotropy in the vicinity of the flame fronts. The localised subgrid scale model predicts significantly enhanced energy generation and less unburnt carbon and oxygen at low velocities compared to earlier simulations.

W. Schmidt; J. C. Niemeyer; W. Hillebrandt; F. K. Roepke

2006-01-23T23:59:59.000Z

Note: This page contains sample records for the topic "dynamic simulation tool" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Life Cycle of Numerically Simulated Shallow Cumulus Clouds. Part II: Mixing Dynamics  

Science Conference Proceedings (OSTI)

This paper is the second in a two-part series in which life cycles of six numerically simulated shallow cumulus clouds are systematically examined. The six clouds, selected from a single realization of a large-eddy simulation, grow as a series of ...

Ming Zhao; Philip H. Austin

2005-05-01T23:59:59.000Z

442

Simulated annealing procedure for on-line control with process dynamics  

Science Conference Proceedings (OSTI)

We study the problem of economic design for a control policy where the sampling interval (m) and control limit (d) are determined by minimizing the expected total quality costs. In this article, we propose a simulated annealing scheme applicable ... Keywords: ARIMA process, Taguchi's method, control policy, expected quality cost, simulated annealing

Shihyu Chou; Min-Chiang Wang

2007-08-01T23:59:59.000Z

443

Building Energy Software Tools Directory : Weather Tool  

NLE Websites -- All DOE Office Websites (Extended Search)

Weather Tool Back to Tool Screenshot for Weather Tool. Screenshot for Weather Tool. Screenshot for Weather...

444

Dynamic simulations of pathways downstream of ERBB-family: exploration of parameter space and effects of its variation on network behavior  

Science Conference Proceedings (OSTI)

The signaling-network immediately downstream of the ErbB-family is very important in BC and other cancers, especially considering treatment of the excess of function of dominant onco-proteins with oncoprotein inhibitors. We studied and implemented dynamic ... Keywords: ErbB-family, dynamic simulations, onco-protein inhibitors, oncogene mutations, parameter space, signaling-networks, systems biology

Lorenzo Tortolina; Nicoletta Castagnino; Cristina De Ambrosi; Raffaele Pesenti; Franco Patrone; Alberto Ballestrero; Eva Moran; Alessio Nencioni; Silvio Parodi

2010-09-01T23:59:59.000Z

445

Molecular dynamics simulation of complex molecules at interfaces: dendritic surfactants in clay and amyloid peptides near lipid bilayers  

E-Print Network (OSTI)

We apply a molecular dynamics (MD) simulation technique to complex molecules at interfaces. Partitioning of dendritic surfactants into clay gallery and Ab protein behavior near hydrated lipids are chosen for the purpose. Using a full atomistic model of dendritic surfactants, the confinement force profiles featuring oscillatory fashion at moderate layer separation of 10 to 25 Å were observed. Integration of the confinement forces led to free energy profiles, which, in turn, were used to determine the final morphology of the nanocomposite. From the free energy profiles, smaller and linear surfactants (G1 and G2L) are expected to intercalate into the clay comfortably, while larger surfactants (G2 and G3) are expected to form frustrated intercalated structures due to the location and depth of the free energy minima. This would agree with the previous observations. As primary steps to understand the Ab protein behavior under biological conditions, simulations of bulk water and hydrated lipids were performed and the results were compared with the literature. Hydrated lipids were simulated using a full atomistic model of lipids (dipalmitoylphosphatidylcholine) and water with a cvff force-field and it was found that structural properties such as the molecular head group area and membrane thickness were accurately produced with MD simulation. Systems of the protein Ab(1-42) in bulk water were simulated and some secondary structural change, with loss of part of the a-helical structure, occurred during the 1 ns of simulation time at 323K. The fragment Ab(31-42) with b-sheet conformation was also simulated in bulk water, and the extended b-sheet structure became a bent structure. Simulations of Ab(1- 42) or Ab(31-42) near lipid bilayers have been performed to investigate the structural property changes under biological conditions. The different nature of structural change was observed from the simulations of the protein or fragment in water and near lipid bilayers due to the different solvent environment. The protein has close contacts with the membrane surface. It was impossible to observe the conformational change to b-sheet and protein entrance into the lipid bilayer within 1 ns simulations.

Han, Kunwoo

2006-08-01T23:59:59.000Z

446

Gulf Stream Simulations and the Dynamics of Ring and Meander Processes  

Science Conference Proceedings (OSTI)

We present here a regional, eddy resolving, numerical study of the dynamics of Gulf Stream Meander and Ring (GSMR) interaction processes. We initialize the Harvard quasi-geostrophic open-boundary model with realistic meander and ring locations as ...

Allan R. Robinson; Michael A. Spall; Nadia Pinardi

1988-12-01T23:59:59.000Z

447

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the application of high performance computing to accelerate the development of hypergolic propulsion systems for tactical missiles. Computational fluid dynamics is employed to model the chemically reacting flow within a system's ...

M. Nusca; C.-C. Chen; M. McQuaid

2007-06-01T23:59:59.000Z

448

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the development and application of high performance computing for the acceleration of tactical missile hypergolic propulsion system development. Computational fluid dynamics is employed to model the chemically reacting flow within ...

Michael J. Nusca; Michael J. McQuaid

2006-06-01T23:59:59.000Z

449

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the development and application of high performance computing for the acceleration of tactical missile hypergolic propulsion system development. Computational fluid dynamics (CFD) is employed to model the chemically reacting flow ...

Michael J. Nusca; Michael J. McQuaid

2005-06-01T23:59:59.000Z

450

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the application of high performance computing to accelerate the development of hypergolic propulsion systems for tactical missiles. Computational fluid dynamics is employed to model the chemically reacting flow within a system’s ...

Michael J. Nusca; Chiung-Chu Chen; Michael J. McQuaid

2008-07-01T23:59:59.000Z

451

Dynamics of Sheared Convective Boundary Layer Entrainment. Part I: Methodological Background and Large-Eddy Simulations  

Science Conference Proceedings (OSTI)

The reported study examines the dynamics of entrainment and its effects on the evolution of the dry atmospheric convective boundary layer (CBL) when wind shear is present. The sheared CBL can be studied by means of direct measurements in the ...

Robert J. Conzemius; Evgeni Fedorovich

2006-04-01T23:59:59.000Z

452

Computational Fluid Dynamic Simulations of Plume Dispersion in Urban Oklahoma City  

Science Conference Proceedings (OSTI)

A 3D computational fluid dynamics study using Reynolds-averaged Navier–Stokes modeling was conducted and validated with field data from the Joint Urban 2003 dispersion study in Oklahoma City, Oklahoma. The modeled flow field indicated that the ...

Julia E. Flaherty; David Stock; Brian Lamb

2007-12-01T23:59:59.000Z

453

Simulating Competition and Coexistence between Plant Functional Types in a Dynamic Vegetation Model  

Science Conference Proceedings (OSTI)

The global distribution of vegetation is broadly determined by climate, and where bioclimatic parameters are favorable for several plant functional types (PFTs), by the competition between them. Most current dynamic global vegetation models (...

Vivek K. Arora; George J. Boer

2006-05-01T23:59:59.000Z

454

Structure and Dynamics of N, N-diethyl-N-methylammonium Triflate Ionic Liquid, Neat and with Water, from Molecular Dynamics Simulations  

DOE Green Energy (OSTI)

We investigated by means of molecular dynamics simulations the properties (structure, thermodynamics, ion transport, and dynamics) of the protic ionic liquid N,N-diethyl-N-methyl-ammonium triflate (dema:Tfl) and of selected aqueous mixtures of dema:Tfl. This ionic liquid, a good candidate for a water-free proton exchange membrane, is shown to exhibit high ion mobility and conductivity. For bulk melts in the temperature range of 303-453K, both liquid densities and enthalpies of vaporization are found to decrease roughly linearly with increasing temperature. The radial distribution functions reveal a significant long-range structural correlation. The ammonium cations [dema]+ are found to diffuse slightly faster than the triflate anions [Tfl]-, and both types of ions exhibit enhanced mobility at higher temperatures, leading to higher ionic conductivity of these ionic liquids. Analysis of the dynamics of ion pairing clearly points to the existence of long-lived contact ion pairs in this ionic liquid. We also examined the effects of water on the ionic properties of dema:Tfl-water mixtures. From the structural analysis it was found that water molecules tend to replace counter ions in the coordination shell and hydrogen bond to both ions, thus weakening their mutual association. As water concentration increases, water molecules start to connect with each other and eventually form a large network that percolates through the system. It is also found that water has a strong influence on the ion dynamics in the mixtures. As the concentration of water increases, both translational and rotational motion of [dema]+ and [Tfl]- are significantly enhanced. As a result, higher ionic conductivity is observed with increased hydration level. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Chang, Tsun-Mei; Dang, Liem X.; Devanathan, Ramaswami; Dupuis, Michel

2010-12-09T23:59:59.000Z

455

Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures  

E-Print Network (OSTI)

Early maturation processes in coal. Part 2: Reactive dynamics simulations using the ReaxFF reactive force field on Morwell Brown coal structures Elodie Salmon a , Adri C.T. van Duin b , François Lorant Brown coal using the ReaxFF reactive force field. We find that these reactive MD simulations

Goddard III, William A.

456

Neighbor List Collision-Driven Molecular Dynamics Simulation for Nonspherical Particles. I. Algorithmic Details II. Applications to Ellipses and Ellipsoids  

E-Print Network (OSTI)

In the first part of a series of two papers, we present in considerable detail a collision-driven molecular dynamics algorithm for a system of nonspherical particles, within a parallelepiped simulation domain, under both periodic or hard-wall boundary conditions. The algorithm extends previous event-driven molecular dynamics algorithms for spheres. We present a novel partial-update near-neighbor list (NNL) algorithm that is superior to previous algorithms at high densities, without compromising the correctness of the algorithm. This efficiency of the algorithm is further increased for systems of very aspherical particles by using bounding sphere complexes (BSC). In the second part of this series of papers we apply the algorithm presented in the first part of this series of papers to systems of hard ellipses and ellipsoids. The theoretical machinery needed to treat such particles, including the overlap potentials, is developed in full detail. We describe an algorithm for predicting the time of collision for tw...

Donev, A; Stillinger, F H; Donev, Aleksandar; Torquato, Salvatore; Stillinger, Frank H.

2004-01-01T23:59:59.000Z

457

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

Chile C Tool Applications Free Recently Updated Cepenergy Management Software for Buildings Energy management, energy efficiency, energy evaluation, energy simulation, energy...

458

Building Energy Software Tools Directory: Tools by Country -...  

NLE Websites -- All DOE Office Websites (Extended Search)

Denmark B I T Tool Applications Free Recently Updated Be06 energy performance, building regulations, house, office, commercial and institutional BSim building simulation, energy,...