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Note: This page contains sample records for the topic "flow simulation assisted" 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.


1

Simulation-assisted inductive learning  

Science Conference Proceedings (OSTI)

Learning by induction can require a large number of training examples. We show the power of using a simulator to generate training data and test data in learning rules for an expert system. The induction program is RL, a simplified version of Meta-DENDRAL. The expert system is ABLE, a rule-based system that identifies and located errors in particle beam lines used in high energy physics. A simulator of beam lines allowed forming and testing rules on sufficient numbers of cases that ABLE's performance is demonstrably accurate and precise. 13 refs., 2 figs.

Buchanan, B.G.; Sullivan, J.; Cheng, Tze-Pin; Clearwater, S.H.

1988-01-01T23:59:59.000Z

2

Large Scale Simulation of Particulate Flows  

Science Conference Proceedings (OSTI)

Simulations of particles in fluid flows are of great interest to numerous industries using sedimentation, fluidization, lubricated transport, and hydraulic fracturing of hydrocarbon reservoirs. Simulating incompressible viscoelastic flows with millions ...

Ahmed H. Sameh; Vivek Sarin

1999-04-01T23:59:59.000Z

3

Computer-Simulation-Assisted Lean Manufacturing Training.  

E-Print Network (OSTI)

??This thesis assesses the potential of using computer simulation to aid existing lean manufacturing training methods such as lecture and live simulation. An investigation of… (more)

Wang, Luoding 1970-

2005-01-01T23:59:59.000Z

4

Social Choice in a Computer-Assisted Simulation  

Science Conference Proceedings (OSTI)

Pursuing a line of inquiry suggested by Crookall, Martin, Saunders, and Coote, the author applied, within the framework of design science, an optimal-design approach to incorporate into a computer-assisted simulation two innovative social choice processes: ... Keywords: GEO, affinity propagation, assessment of learning, business, bustling market, clustering algorithm, computer-assisted, continuous voting, periodic double auction, proposal voting, social choice

Precha Thavikulwat

2009-08-01T23:59:59.000Z

5

COMPUTER SIMULATION OF SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE  

E-Print Network (OSTI)

COMPUTER SIMULATION OF SINGLE-WELL STEAM ASSISTED GRAVITY DRAINAGE (SW-SAGD) TR 119 By Keith T of Sensitivity Analysis Cases 32 #12;v List of Figures Figure 1: Steam Assisted Gravity Drainage Concept: Recovery Factor vs. Time for All Cases (10 Years Production) 13 Figure 8: Cumulative Steam-Oil Ratio vs

6

LES algorithm for turbulent reactive flows simulation  

Science Conference Proceedings (OSTI)

The paper presents the development and implementation of a Large Eddy Simulation numerical algorithm for simulating turbulent reactive flows. The numerical algorithm is based on a 5 step modified Runge - Kutta numerical scheme with a dual time stepping ... Keywords: Runge - Kutta numerical scheme, large eddy simulation, linear eddy model

Ionut Porumbel; Cristian Cârl?nescu; Florin Gabriel Florean; Constantin Eusebiu Hritcu

2010-10-01T23:59:59.000Z

7

Flow-Assisted Flame Propagation Through a Porous Combustible in Microgravity  

E-Print Network (OSTI)

P.J. Pagni and T.G. Peterson, “Flame Spread Through PorousT. Niioka, ”Flow-Assisted Flame Propagation Through a PorousMarch 2002 Flow-Assisted Flame Propagation Through a Porous

Bar-Ilan, Amnon; Rich, David B; Rein, Guillermo; Fernandez-Pello, Carlos; Hanai, H.; Niioka, T.

2002-01-01T23:59:59.000Z

8

Assembly flow simulation of a radar  

Science Conference Proceedings (OSTI)

A discrete event simulation model has been developed to predict the assembly flow time of a new radar product. The simulation was the key tool employed to identify flow constraints. The radar, production facility, and equipment complement were designed, arranged, and selected to provide the most manufacturable assembly possible. A goal was to reduce the assembly and testing cycle time from twenty-six weeks to six weeks. A computer software simulation package (SLAM II) was utilized as the foundation a for simulating the assembly flow time. FORTRAN subroutines were incorporated into the software to deal with unique flow circumstances that were not accommodated by the software. Detailed information relating to the assembly operations was provided by a team selected from the engineering, manufacturing management, inspection, and production assembly staff. The simulation verified that it would be possible to achieve the cycle time goal of six weeks. Equipment and manpower constraints were identified during the simulation process and adjusted as required to achieve the flow with a given monthly production requirement. The simulation is being maintained as a planning tool to be used to identify constraints in the event that monthly output is increased. ``What-if`` studies have been conducted to identify the cost of reducing constraints caused by increases in output requirement.

Rutherford, W.C.; Biggs, P.M.

1993-10-01T23:59:59.000Z

9

Experimental calibration of a coupled reaction-flow simulator  

SciTech Connect

Two flow-through experiments in sandstone were conducted to assess the impact of artificial diagenesis (neogenesis) during steam-assisted oil recovery in a bitumen reservoir in NE-Alberta, Canada (Clearwater formation). The benchmark experiments were designed to calibrate and validate a reaction-flow simulator (REACTRAN). Because of the system's complexity, the simulator has to be validated in the laboratory before being used in field applications. In the second experiment, reported on here, the Impact of neogenesis on preserved core from the field was investigated. Salient features of the experiment are: fluid composition - brine, pH 9.5; injection time - 28 days; temperature - 246[degrees]C; sediment - bitumen extracted, immature, litharenite sand; permeability - 3 Darcies; system length - 90 cm; flow rate - 10.2 cc/h. The initial and rock composition were analyzed. We found: (1) small overall permeability reduction (8%), (2) the post-steam core remained unconsolidated; (3) the most reactive sand components are carbonates and the matrix of volcanic rock fragments; (4) many plagioclase grains were dissolved; (5) K-feldspar, smectite, and chlorite were formed. These results show promising agreement between REACTRAN predictions and the laboratory experiments. In the near future, such experimentally calibrated simulators may be effective in predicting beneficial and deleterious reactions that may occur during thermally-assisted oil recovery.

Mok, U.; Longstaffe, F.J. (Univ. of Western Ontario, London, Ontario (Canada)); Dudley, S. (Imperial Oil Res. Limited, Calgary, Alberta (Canada)) (and others)

1996-01-01T23:59:59.000Z

10

Simulation of air flow in the typical boiler windbox segments  

Science Conference Proceedings (OSTI)

Simulation of turbulent air flow distribution in CFBC furnace, wherein primary air is entrained through inlet duct system called windbox, is attempted through state of art CAD/CFD softwares. Establishment of flow in windbox channel, distributed plate ... Keywords: CFBC boiler, air flow, combustor geometry, distributed plate nozzles, multi-block grids, recirculation flow, simulation of flow, unequal air flow, windbox channel

C. Bhasker

2002-12-01T23:59:59.000Z

11

Modeling and Simulation of a Solar Assisted Desiccant Cooling System  

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

Modeling and Simulation of a Solar Assisted Desiccant Cooling System Modeling and Simulation of a Solar Assisted Desiccant Cooling System Speaker(s): Chadi Maalouf Date: December 2, 2004 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Peng Xu Increased living standards and high occupants comfort demands lead to a growth in air conditioning market. This results in high energy consumption and high CO2 emissions. For these reasons, the solar desiccant cooling system is proposed as an alternative to traditional air conditioning systems. This system comprises a desiccant wheel containing Lithium Chloride in tandem with a rotating heat exchanger and two humidifiers on both supply and return air. The required regeneration temperature for the desiccant wheel varies between 40oC and 70oC which makes possible the use

12

A macroscopic collisional model for debris-flows simulation  

Science Conference Proceedings (OSTI)

SCIDDICA S"4"c is the latest hexagonal release of a family of Cellular Automata models for the simulation of flow-type landslides. It is able to simulate the erosion of the regolith along the flow path, besides branching and re-joining events of the ... Keywords: Calibration, Cellular automata, Debris flows, Genetic algorithms, Modelling, Parallel processing, Sarno, Sensitivity analysis, Simulation

Donato D'Ambrosio; Giulio Iovine; William Spataro; Hideaki Miyamoto

2007-10-01T23:59:59.000Z

13

GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS  

E-Print Network (OSTI)

Simulation of Fluid Flow in Fractured Porous Media, Watergovern fluid flow in fractured porous media. These are (i)for Modeling Fluid and Heat Flow in fractured Porous Media,

Pruess, K.

2010-01-01T23:59:59.000Z

14

Adaptive LES Methodology for Turbulent Flow Simulations  

Science Conference Proceedings (OSTI)

Although turbulent flows are common in the world around us, a solution to the fundamental equations that govern turbulence still eludes the scientific community. Turbulence has often been called one of the last unsolved problem in classical physics, yet it is clear that the need to accurately predict the effect of turbulent flows impacts virtually every field of science and engineering. As an example, a critical step in making modern computational tools useful in designing aircraft is to be able to accurately predict the lift, drag, and other aerodynamic characteristics in numerical simulations in a reasonable amount of time. Simulations that take months to years to complete are much less useful to the design cycle. Much work has been done toward this goal (Lee-Rausch et al. 2003, Jameson 2003) and as cost effective accurate tools for simulating turbulent flows evolve, we will all benefit from new scientific and engineering breakthroughs. The problem of simulating high Reynolds number (Re) turbulent flows of engineering and scientific interest would have been solved with the advent of Direct Numerical Simulation (DNS) techniques if unlimited computing power, memory, and time could be applied to each particular problem. Yet, given the current and near future computational resources that exist and a reasonable limit on the amount of time an engineer or scientist can wait for a result, the DNS technique will not be useful for more than 'unit' problems for the foreseeable future (Moin & Kim 1997, Jimenez & Moin 1991). The high computational cost for the DNS of three dimensional turbulent flows results from the fact that they have eddies of significant energy in a range of scales from the characteristic length scale of the flow all the way down to the Kolmogorov length scale. The actual cost of doing a three dimensional DNS scales as Re{sup 9/4} due to the large disparity in scales that need to be fully resolved. State-of-the-art DNS calculations of isotropic turbulence have recently been completed at the Japanese Earth Simulator (Yokokawa et al. 2002, Kaneda et al. 2003) using a resolution of 40963 (approximately 10{sup 11}) grid points with a Taylor-scale Reynolds number of 1217 (Re {approx} 10{sup 6}). Impressive as these calculations are, performed on one of the world's fastest super computers, more brute computational power would be needed to simulate the flow over the fuselage of a commercial aircraft at cruising speed. Such a calculation would require on the order of 10{sup 16} grid points and would have a Reynolds number in the range of 108. Such a calculation would take several thousand years to simulate one minute of flight time on today's fastest super computers (Moin & Kim 1997). Even using state-of-the-art zonal approaches, which allow DNS calculations that resolve the necessary range of scales within predefined 'zones' in the flow domain, this calculation would take far too long for the result to be of engineering interest when it is finally obtained. Since computing power, memory, and time are all scarce resources, the problem of simulating turbulent flows has become one of how to abstract or simplify the complexity of the physics represented in the full Navier-Stokes (NS) equations in such a way that the 'important' physics of the problem is captured at a lower cost. To do this, a portion of the modes of the turbulent flow field needs to be approximated by a low order model that is cheaper than the full NS calculation. This model can then be used along with a numerical simulation of the 'important' modes of the problem that cannot be well represented by the model. The decision of what part of the physics to model and what kind of model to use has to be based on what physical properties are considered 'important' for the problem. It should be noted that 'nothing is free', so any use of a low order model will by definition lose some information about the original flow.

Oleg V. Vasilyev

2008-06-12T23:59:59.000Z

15

Computerized Games and Simulations in Computer-Assisted Language Learning: A Meta-Analysis of Research  

Science Conference Proceedings (OSTI)

This article explores research on the use of computerized games and simulations in language education. The author examined the psycholinguistic and sociocultural constructs proposed as a basis for the use of games and simulations in computer-assisted ... Keywords: CALL, MMORPG, MOO, computer-assisted language learning, computerized game, computerized simulation, effective language learning, gaming, meta-analysis, psycholinguistic construct, research, second language acquisition, simulation, sociocultural construct, theories of language acquisition, virtual world

Mark Peterson

2010-02-01T23:59:59.000Z

16

Incompressible and Anelastic Flow Simulations on Numerically Generated Grids  

Science Conference Proceedings (OSTI)

In the numerical simulation of incompressible and anelastic flows, it is necessary to solve an elliptic equation at each time step. When the boundaries of such flows are nonrectangular, it may be advantageous to solve the equations on a new, ...

R. D. Sharman; T. L. Keller; M. G. Wurtele

1988-05-01T23:59:59.000Z

17

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive...  

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

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive Transport Processes Associated with Carbon Sequestration PI Name: David Trebotich Institution: Lawrence Berkeley...

18

Design, construction and evaluation of a simulated geothermal flow system  

Science Conference Proceedings (OSTI)

A system was designed and built to simulate the flow from a geothermal well. The simulated flow will be used to power a Lysholm engine, the performance of which will then be evaluated for different simulated geothermal flows. Two main subjects are covered: 1) the design, construction and evaluation of the behavior of the system that simulates the geothermal flow; included in that topic is a discussion of the probable behavior of the Lysholm engine when it is put into operation, and 2) the investigation of the use of dynamic modeling techniques to determine whether they can provide a suitable means for predicting the behavior of the system.

Mackanic, J.C.

1980-07-28T23:59:59.000Z

19

ESS 2012 Peer Review - Flow-Assisted Zinc Anode Batteries for...  

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

6&91&>09-+&@C:40(:&O7B0& %.PQRR340(+;"""GS8P(+:S:75& FLOW-ASSISTED ZINC ANODE BATTERIES FOR GRID-SCALE ELECTRICITY STORAGE Prof. Sanjoy Banerjee, banerjee@che.ccny.cuny.e...

20

Using large eddy simulations to understand flow mixing | Argonne National  

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

large eddy simulations to understand flow mixing large eddy simulations to understand flow mixing March 4, 2013 Tweet EmailPrint In nuclear power plants, turbulent flow streams of different velocity and density mix rapidly at right angles in pipes. If those mixing flow streams are of different temperatures, thermal fluctuations result on the pipe wall. Such fluctuations can damage a pipe's structure and, ultimately, cause its failure. To better understand this phenomenon and to predict the effects, scientists have developed modeling methods known as large eddy simulations (LES). LES models only the energy-carrying large scales of motion, using a filtering mechanism to account for subgrid-scale motion. Thanks to recent advances in high-performance computing, the technique has become increasingly popular for simulating unsteady flows, allowing high fidelity

Note: This page contains sample records for the topic "flow simulation assisted" 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

Visualizing flow patterns in coupled geomechanical simulation using streamlines  

E-Print Network (OSTI)

Reservoir geomechanics is a production induced phenomena that is experienced in large number of fields around the world. Hydrocarbon production changes the pore pressure which in turn alters the in-situ stress state. For reservoirs that are either stress sensitive or where rock is soft and unconsolidated, stresses have appreciable effect on rock properties like porosity and permeability. Anisotropic and isotropic permeability changes affect flow direction and movement of flood front thereby influencing well performance and reservoir productivity. Coupling of geomechanical calculation with multi-phase flow calculation is needed to make prudent predictions about the reservoir production and recovery. The post processing tools provided with the simulators cannot monitor flood front movement and fail to capture important information like flow directionality and dominant phase in a flow. Geomechanical simulation is combined with streamline tracing to aid in better understanding of the reservoir dynamics through visualization of flow patterns in the reservoir. Streamline tracing is a proved reservoir engineering tool that is widely used by industry experts to capture information on flood movement, injector-producer relations and swept area. In the present research, we have incorporated total velocity streamlines and phase streamlines for coupled geomechanical simulation and compared the results with streamline tracing for conventional reservoir simulator to explain geomechanics behavior on reservoir flow processes in a more detailed and appealing manner. Industry standard simulators are used for coupled geomechanical simulation and conventional simulation and streamline tracing has been done through in-house tracing code. The research demonstrates the benefits and power of streamline tracing in visualizing flow patterns through work on two cases; first, a synthetic case for studying water injection in a five spot pattern and second, a SPE 9th comparative study. The research gives encouraging results by showing how geomechanics influences reservoir flow paths and reservoir dynamics through visualization of flow. The streamlines captures flow directionality, information regarding appearance and disappearance of gas phase and the connectivity between injector and producer.

Parihar, Prannay

2008-12-01T23:59:59.000Z

22

A CFD Model for Simulating Urban Flow and Dispersion  

Science Conference Proceedings (OSTI)

A three-dimensional computational fluid dynamics (CFD) model is developed to simulate urban flow and dispersion, to understand fluid dynamical processes therein, and to provide practical solutions to some emerging problems of urban air pollution. ...

Jong-Jin Baik; Jae-Jin Kim; Harindra J. S. Fernando

2003-11-01T23:59:59.000Z

23

Flow simulations using particles: bridging computer graphics and CFD  

Science Conference Proceedings (OSTI)

The simulation of the motion of interacting particles is a deceivingly simple, yet powerful and natural method for exploring and animating flows in physical systems as diverse as planetary dark accretion and sea waves, unsteady aerodynamics and nanofluidics.

Petros Koumoutsakos; Georges-Henri Cottet; Diego Rossinelli

2008-08-01T23:59:59.000Z

24

High Performance Flow Simulations on Graphics Processing Units  

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

High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar HostPoint of Contact: Michael Wetter...

25

Field Assisted Viscous Flow and Crystallization in a Sodium ...  

Science Conference Proceedings (OSTI)

The onset of viscous flow is accompanied by an equally abrupt transition in the ... A History of the Theories of Glass Structure: Can We Really Believe What is ... Mechanisms of the Conversion Reaction in FeF2 Cathodes Exposed to Li in High

26

Multiscale CFD simulations of entrained flow gasification  

E-Print Network (OSTI)

The design of entrained flow gasifiers and their operation has largely been an experience based enterprise. Most, if not all, industrial scale gasifiers were designed before it was practical to apply CFD models. Moreover, ...

Kumar, Mayank, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

27

Fast and informative flow simulation in a building by using fast...  

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

and informative flow simulation in a building by using fast fluid dynamics model on graphics processing unit Title Fast and informative flow simulation in a building by using...

28

CFD simulation of neutral ABL flows Xiaodong Zhang  

E-Print Network (OSTI)

in the atmosphere, prediction of wind load on structure, analysis of wind flow patterns in urban area flow field over different terrains employing Fluent 6.3 software. How accurate the simulation could.2 Problem analysis 18 3.3 User-defined wall functions 18 3.4 Results from different model settings 19 3

29

Numerical Simulation of Slope and Mountain Flows  

Science Conference Proceedings (OSTI)

Early descriptive models of mountain-valley circulations indicated that the mountain flow (i.e., the along-valley axis component out of the valley) is a true three-dimensional phenomenon. According to these descriptions, at night shallow-down ...

Richard T. McNider; Roger A. Pielke

1984-10-01T23:59:59.000Z

30

High Performance Flow Simulations on Graphics Processing Units  

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

High Performance Flow Simulations on Graphics Processing Units High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Michael Wetter Building design and operation often requires real-time or faster-than-real-time simulations for detailed information on air distributions. However, none of the current flow simulation techniques can satisfy this requirement. To solve this problem, a Fast Fluid Dynamics (FFD) model has been developed. The FFD can solve Navier-Stokes equations at a speed of 50 times faster than Computational Fluid Dynamics (CFD). In addition, the computing speed of the FFD program has been further enhanced up to 30 times by executing in parallel on a Graphics Processing Unit (GPU) instead of a Central Processing Unit (CPU). As a whole, the FFD on a GPU

31

NANOSECOND PULSE NONEQUILIBRIUM DISCHARGES FOR HIGH SPEED FLOW CONTROL AND PLASMA ASSISTED COMBUSTION  

E-Print Network (OSTI)

their poten tial for engineering applications such as plasma assisted combustion, highspeed flow con trol by RNSPD and compared with kinetic model ing. The results show that ignition in a uniform plasma occurs Engi neering from Moscow Institute of Physics and Technology and a Ph.D. in Chemical Physics from OSU

Shyy, Wei

32

Petascale Direct Numerical Simulations of Turbulent Channel Flow  

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

Petascale Petascale Direct Numerical Simulations of Turbulent Channel Flow MyoungKyu Lee mk@ices.utexas.edu Department of Mechanical Engineering University of Texas at Austin ESP Meeting May, 2013 M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 1 / 30 Contents Project Overview Performance Optimization Early Result Conclusion M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 2 / 30 Project Overview Project Title â—® Petascale Direct Numerical Simulations of Turbulent Channel Flow Goal â—® Expanding our understand of wall-bounded turbulence Personnel â—® P.I. : Robert Moser â—® Primary Developer : M.K.Lee â—® Software Engineering Support : Nicholas Malaya â—® Catalyst : Ramesh Balakrishnan M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 3 / 30 Turbulent

33

Flow simulation in industrial cyclone separator  

Science Conference Proceedings (OSTI)

The problem of ash settling on super-heater tube bank, due to improper velocity distribution, in the cyclone separator used at Circulating Fluidized Bed Combustion (CFBC) has been investigated by means of computational fluid dynamic techniques. With ... Keywords: CAD model, CFD - finite volume technique, Circulating fluidized bed combustion, Flow recirculation - geometry modification, Particle Trajectories, Partition plates, Pressure based algorithms, Pressure drop, Recycle cyclone collector, Structured multi-block grids

C. Bhasker

2010-02-01T23:59:59.000Z

34

Numerical and experimental investigations on vibration of simulated CANDU fuel bundles subjected to turbulent fluid flow.  

E-Print Network (OSTI)

??Vibration of simulated CANDU fuel bundles induced by coolant flow is investigated in this thesis through experiments and numerical simulations. Two simulated bundles and a… (more)

Zhang, Xuan

2011-01-01T23:59:59.000Z

35

High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

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

A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension. In this snapshot of the simulation, the stress on each suspended particle is shown color-coded with its specific value drawn on its surface. Suspended particles that have a stress value below a specific threshold value are shown in outline form in order to better view those particles that are carrying the majority of the stress in the system. This image and the software used to produce it was developed by Steven Satterfield, John Hagedorn, and John Kelso of the National Institute of Standards and Technology (NIST), and Marc Olano of NIST and the University of Maryland-Baltimore County. High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry

36

Simulation of Combustion and Thermal Flow in an Industrial Boiler  

E-Print Network (OSTI)

Industrial boilers that produce steam or electric power represent a crucial facility for overall plant operations. To make the boiler more efficient, less emission (cleaner) and less prone to tube rupture problems, it is important to understand the combustion and thermal flow behaviors inside the boiler. This study performs a detailed simulation of combustion and thermal flow behaviors inside an industrial boiler. The simulations are conducted using the commercial CFD package FLUENT. The 3-D Navier-Stokes equations and five species transport equations are solved with the eddy-breakup combustion model. The simulations are conducted in three stages. In the first stage, the entire boiler is simulated without considering the steam tubes. In the second stage, a complete intensive calculation is conducted to compute the flow and heat transfer across about 496 tubes. In the third stage, the results of the saturator/superheater sections are used to calculate the thermal flow in the chimney. The results provide insight into the detailed thermal-flow and combustion in the boiler and showing possible reasons for superheater tube rupture. The exhaust gas temperature is consistent with the actual results from the infrared thermograph inspection.

Saripalli, R.; Wang, T.; Day, B.

2005-01-01T23:59:59.000Z

37

Modeling and simulation to assist context aware system design  

Science Conference Proceedings (OSTI)

In this paper we present a modelling and visualization design approach for context-aware systems, specifically focusing on applications that support location tracking and that exhibit their behaviour as actuations in the deployment environment. The design ... Keywords: Context awareness, design tool, modelling, prototyping, simulation, test-bed, ubiquitous computing

Eleanor O'Neill; Owen Conlan; David Lewis

2011-01-01T23:59:59.000Z

38

Numerical simulation of low Mach number reacting flows  

Science Conference Proceedings (OSTI)

Using examples from active research areas in combustion andastrophysics, we demonstrate a computationally efficient numericalapproach for simulating multiscale low Mach number reacting flows. Themethod enables simulations that incorporate an unprecedented range oftemporal and spatial scales, while at the same time, allows an extremelyhigh degree of reaction fidelity. Sample applications demonstrate theefficiency of the approach with respect to a traditional time-explicitintegration method, and the utility of the methodology for studying theinteraction of turbulence with terrestrial and astrophysical flamestructures.

Bell, John B.; Aspden, Andrew J.; Day, Marcus S.; Lijewski,Michael J.

2007-06-20T23:59:59.000Z

39

Numerical Simulation of Katabatic Flow with Changing Slope Angle  

Science Conference Proceedings (OSTI)

A large eddy simulation (LES) model and the Advanced Regional Prediction System (ARPS) model, which does not resolve turbulent eddies, are used to study the effect of a slope angle decrease on the structure of katabatic slope flows. For a simple, ...

Craig M. Smith; Eric D. Skyllingstad

2005-11-01T23:59:59.000Z

40

MPSalsa 3D Simulations of Chemically Reacting Flows  

DOE Data Explorer (OSTI)

Many important scientific and engineering applications require a detailed analysis of complex systems with coupled fluid flow, thermal energy transfer, mass transfer and nonequilibrium chemical reactions. Currently, computer simulations of these complex reacting flow problems are limited to idealized systems in one or two spatial dimensions when coupled with a detailed, fundamental chemistry model. The goal of our research is to develop, analyze and implement advanced MP numerical algorithms that will allow high resolution 3D simulations with an equal emphasis on fluid flow and chemical kinetics modeling. In our research, we focus on the development of new, fully coupled, implicit solution strategies that are based on robust MP iterative solution methods (copied from http://www.cs.sandia.gov/CRF/MPSalsa/). These simulations are needed for scientific and technical areas such as: combustion research for transportation, atmospheric chemistry modeling for pollution studies, chemically reacting flow models for analysis and control of manufacturing processes, surface catalytic reactors for methane to methanol conversion and chemical vapor deposition (CVD) process modeling for production of advanced semiconductor materials (http://www.cs.sandia.gov/CRF/MPSalsa/).

This project website provides six QuickTime videos of these simulations, along with a small image gallery and slideshow animations. A list of related publications and conference presentations is also made available.

Note: This page contains sample records for the topic "flow simulation assisted" 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

Simulations of Turbulent Flows with Strong Shocks and Density Variations  

SciTech Connect

In this report, we present the research efforts made by our group at UCLA in the SciDAC project ���¢��������Simulations of turbulent flows with strong shocks and density variations���¢�������. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

Xiaolin Zhong

2012-12-13T23:59:59.000Z

42

Protected Loss of Flow Transient Simulation (Quicktime format, High  

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

Engineering Analysis > Videos Engineering Analysis > Videos Engineering Analysis: Protected Loss of Flow Transient Simulation Quicktime format Quicktime Format - High Bandwidth | Size: 25.94 MB | Bit Rate: 1148 kbps Keywords: flow transient, plot, EBR-II, SAS4A, SASSYS-1, passive safety, protected loss of flow, PLOF, shutdown heat removal test, SHRT-17, SHRT17 Elevation plot showing detailed top of core temperatures in experimental assembly XX09 during a protected loss of flow transient in EBR-II. Surrounding assemblies are depicted using fuel average temperatures. Results show excellent decay heat removal capability of sodium through natural circulation and exceptionally low transient temperatures with metallic fuel. :: Please wait until video loads completely :: Closed Captioning Transcript

43

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

44

Fladmark. Parallel simulation of multiphase/multicomponent flow models  

E-Print Network (OSTI)

Summary. The simulation of flow in porous media is a computationally demanding task. Thermodynamical equilibrium calculations and complex, heterogeneous geological structures normally gives a multiphysics/multidomain problem to solve. Thus, efficient solution methods are needed. The research simulator Athena is a 3D, multiphase, multicomponent, porous media flow simulator. A parallel version of the simulator was developed based on a non-overlapping domain decomposition strategy, where the domains are defined a-priori from e.g. geological data. Selected domains are refined with locally matching grids, giving a globally non-matching, unstructured grid. In addition to the space domain, novel algorithms for parallel processing in time based on a predictor-corrector strategy has been successfully implemented. We discuss how the domain decomposition framework can be used to include different physical and numerical models in selected sub-domains. Also we comment on how the two-level solver relates to multiphase upscaling techniques. Adding communication functionality enables the original serial version to run on each sub-domain in parallel. Motivated by the need for larger time steps, an implicit formulation of the mass transport equations has been formulated and implemented in the existing parallel framework. Further, as the Message Passing Interface (MPI) is used for communication, the simulator is highly portable. Through benchmark experiments, we test the new formulation on platforms ranging from commercial super-computers to heterogeneous networks of workstations. 1

Erlend Řian; Magne S. Espedal; I. Garrido; G. E. Fladmark

2004-01-01T23:59:59.000Z

45

BULK FLOW OF HALOS IN {Lambda}CDM SIMULATION  

Science Conference Proceedings (OSTI)

Analysis of the Pangu N-body simulation validates that the bulk flow of halos follows a Maxwellian distribution with variance that is consistent with the prediction of the linear theory of structure formation. We propose that the consistency between the observed bulk velocity and theories should be examined at the effective scale of the radius of a spherical top-hat window function yielding the same smoothed velocity variance in linear theory as the sample window function does. We compared some recently estimated bulk flows from observational samples with the prediction of the {Lambda}CDM model we used; some results deviate from expectation at a level of {approx}3{sigma}, but the discrepancy is not as severe as previously claimed. We show that bulk flow is only weakly correlated with the dipole of the internal mass distribution, that the alignment angle between the mass dipole and the bulk flow has a broad distribution peaked at {approx}30 Degree-Sign -50 Degree-Sign , and also that the bulk flow shows little dependence on the mass of the halos used in the estimation. In a simulation of box size 1 h {sup -1} Gpc, for a cell of radius 100 h {sup -1} Mpc the maximal bulk velocity is >500 km s{sup -1}; dipoles of the environmental mass outside the cell are not tightly aligned with the bulk flow, but are rather located randomly around it with separation angles {approx}20 Degree-Sign -40 Degree-Sign . In the fastest cell there is a slightly smaller number of low-mass halos; however, halos inside are clustered more strongly at scales {approx}> 20 h {sup -1} Mpc, which might be a significant feature since the correlation between bulk flow and halo clustering actually increases in significance beyond such scales.

Li Ming; Pan Jun; Feng Longlong; Kang Xi [Purple Mountain Observatory, 2 West Beijing Road, Nanjing 210008 (China); Gao Liang [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Jing Yipeng; Yang Xiaohu; Lin Weipeng; Zhao Donghai; Zhang Pengjie [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 200030 (China); Chi Xuebin; Shan Guihua; Wang Long, E-mail: jpan@bao.ac.cn [Supercomputing Center, Computer Network Information Center, Chinese Academy of Sciences, 4 Zhongguancun Nansijie, Haidian District, Beijing 100190 (China)

2012-12-20T23:59:59.000Z

46

Numerical simulation of water flow around a rigid fishing net  

E-Print Network (OSTI)

This paper is devoted to the simulation of the flow around and inside a rigid axisymmetric net. We describe first how experimental data have been obtained. We show in detail the modelization. The model is based on a Reynolds Averaged Navier-Stokes turbulence model penalized by a term based on the Brinkman law. At the out-boundary of the computational box, we have used a "ghost" boundary condition. We show that the corresponding variational problem has a solution. Then the numerical scheme is given and the paper finishes with numerical simulations compared with the experimental data.

Roger Lewandowski; Géraldine Pichot

2006-12-20T23:59:59.000Z

47

Wave–Mean Flow Feedback and the Persistence of Simulated Zonal Flow Vacillation  

Science Conference Proceedings (OSTI)

The structure of eddies forcing the vacillation of the southern midlatitude tropospheric zonal-mean zonal wind and the significance of wave–mean flow feedbacks on its persistence are assessed using a 100-yr 8-h dataset simulated by the ...

I. G. Watterson

2002-04-01T23:59:59.000Z

48

Mathematical Modeling And Simulation For Fluid Flow In Porous Media  

E-Print Network (OSTI)

Mathematical models have been widely used to understand, predict, or optimize many complex physical processes. In particular, simulation of environmental effects of air polution is extensive. Here we address the need for using similar models to understand the fate and transport of groundwater contaminants and to design in situ remediation strategies. Three basic problem areas must be addressed in the modeling and simulation of the flow of groundwater contamination. One must first obtain an effective model to describe the complex fluid/fluid and fluid/rock interactions that control the transport of contaminants in groundwater. This includes the problems of determining and modeling the various multiphase or chemically reactive aspects of the problems which govern the flow of fluids, obtaining accurate reservoir descriptions at various length scales, and modeling the effects of this heterogeneity in the reservoir simulators. Next, one must develop accurate discretization techniques that retain the important physical properties of the continuous models without introducing spurious phenomena related to the discretization errors. Finally, one should develop efficient numerical solution algorithms that utilize the potential of the emerging computing architectures. We will discuss recent advances in each of these three areas.

Richard Ewing

2001-01-01T23:59:59.000Z

49

Assessing continuum postulates in simulations of granular flow  

Science Conference Proceedings (OSTI)

Continuum mechanics relies on the fundamental notion of a mesoscopic volume"element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional Discrete-Element Method (DEM) simulations of different granular flows and show that an approximate"granular element" defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships betweenaverage variables.

Rycroft, Chris; Kamrin, Ken; Bazant, Martin

2008-08-26T23:59:59.000Z

50

PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport, and  

E-Print Network (OSTI)

PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport, and Multicomponent;COVER ILLUSTRATION: Results of PHAST simulation of the evolution of water chemistry in the Central 25 0 50 200 #12;PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport

51

The effect of water flow rate upon the environmentally-assisted cracking response of a low-alloy steel  

SciTech Connect

Effect of water flow rate on the environmentally-assisted cracking (EAC) response of a high-sulfur ferritic steel was studied at 243C. In contrast to earlier studies with compact-type specimens, this study employed relatively large tight semi-elliptical surface cracks tested under generally linear-elastic conditions. Flow velocities parallel to the crack as low as 1.68 {minus} 1.84 m/s were effective in mitigating EAC.

James, L.A.; Wire, G.L. [Westinghouse Electric Corp., West Mifflin, PA (United States). Bettis Atomic Power Lab.; Cullen, W.H. [Materials Engineering Associates, Lanham, MD (United States)

1994-09-01T23:59:59.000Z

52

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

53

Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas  

E-Print Network (OSTI)

for estimates of the oil and gas flow rate from the Macondoteam and carried out oil and gas flow simulations using theoil-gas system. The flow of oil and gas was simulated using

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

54

An unstructured finite volume simulator for multiphase flow through fractured-porous media  

E-Print Network (OSTI)

Modeling of multiphase flow in fractured media plays an integral role in management and performance prediction of oil and gas reserves. Geological characterization and nmultiphase flow simulations in fractured media are ...

Bajaj, Reena

2009-01-01T23:59:59.000Z

55

SIMULATING THE COOLING FLOW OF COOL-CORE CLUSTERS  

SciTech Connect

We carry out high-resolution adaptive mesh refinement simulations of a cool core cluster, resolving the flow from Mpc scales down to pc scales. We do not (yet) include any active galactic nucleus (AGN) heating, focusing instead on cooling in order to understand how gas reaches the supermassive black hole at the center of the cluster. We find that, as the gas cools, the cluster develops a very flat temperature profile, undergoing a cooling catastrophe only in the central 10-100 pc of the cluster. Outside of this region, the flow is smooth, with no local cooling instabilities, and naturally produces very little low-temperature gas (below a few keV), in agreement with observations. The gas cooling in the center of the cluster rapidly forms a thin accretion disk. The amount of cold gas produced at the very center grows rapidly until a reasonable estimate of the resulting AGN heating rate (assuming even a moderate accretion efficiency) would overwhelm cooling. We argue that this naturally produces a thermostat which links the cooling of gas out to 100 kpc with the cold gas accretion in the central 100 pc, potentially closing the loop between cooling and heating. Isotropic heat conduction does not affect the result significantly, but we show that including the potential well of the brightest cluster galaxy is necessary to obtain the correct result. Also, we found that the outcome is sensitive to resolution, requiring very high mass resolution to correctly reproduce the small transition radius.

Li Yuan; Bryan, Greg L. [Department of Astronomy, Pupin Physics Laboratories, Columbia University, New York, NY 10027 (United States)

2012-03-01T23:59:59.000Z

56

Development of kinetic model reduction framework and its application in realistic flow simulation.  

E-Print Network (OSTI)

??The main objective of this research is to develop a kinetic model reduction framework that enables incorporation of detailed chemistry with realistic flow simulation. Comprehensive… (more)

He, Kaiyuan, 1986-

2010-01-01T23:59:59.000Z

57

High Performance Computing Based Methods for Simulation and Optimisation of Flow Problems.  

E-Print Network (OSTI)

??The thesis is concerned with the study of methods in high-performance computing for simulation and optimisation of flow problems that occur in the framework of… (more)

Bockelmann, Hendryk

2010-01-01T23:59:59.000Z

58

Three-Dimensional Numerical Simulations of Strongly Stratified Flow past Conical Orography  

Science Conference Proceedings (OSTI)

Results from a series of numerical simulations of three-dimensional stably stratified flows past conical orography with unit slope are presented and are compared directly with laboratory results from a stratified towing tank. The simulations are ...

S. B. Vosper

2000-11-01T23:59:59.000Z

59

Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark |  

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

Nek5000 Ready to Use after Simulations of Important Pipe Flow Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark January 29, 2013 - 1:42pm Addthis Velocity magnitude in MATiS-H spacer grid with swirl-type vanes. Velocity magnitude in MATiS-H spacer grid with swirl-type vanes. As part of the on-going Nek5000 validation efforts, a series of large eddy simulations (LES) have been performed for thermal stratification in a pipe. Results were in good agreement with the experiment and the simulation data has provided insight into the physics of the flow. An additional series of simulations of the OECD-NEA MATiS-H benchmark has also been completed using intermediate- fidelity modeling approaches, such as k-epsilon, k-omega shear stress transport, and ID detached eddy simulation, as well as one

60

Simulation of bilinear flow in single matrix block drainage  

E-Print Network (OSTI)

This thesis presents modeling of bilinear flow in tight gas wells and its behavior on single matrix block drainage. The objectives of this research are to: simulate a tight gas well using matrix block drainage under constant production pwf and with a constant production rate; be able to predict the behavior of matrix block drainage; study the effect of natural fracture(s) near a well; examine the matrix block drainage in a natural fracture network; and to validate a matrix block drainage model with a hydraulic fracture analytical solution. Two different production scenarios, constant pwf and constant rate, are assigned to a tight gas well in matrix block drainage. Matrix block drainage has two distinct permeabilities; a low permeability matrix serves as the tight gas reservoir with a high permeability streak surrounding the matrix. A well only produces from the high permeability fracture. Models were run with different sensitivity cases toward fracture half length, xf, and fracture permeability kf,. The fracture half-length reflects on a/b aspect ratio. The analytical solution for hydraulic fracture developed by Cinco-Ley and Guppy serves as the validation of matrix block drainage. Analysis on the flow regimes which occurred for different geometries and properties are provided. The log-log diagnostic plot of pseudo-pressure drop/gas rates and the log-log plot of dimensionless pressure derivatives and dimensionless reciprocal production rates are presented. Finally, an attempt to normalize the late time and early time of all geometries and properties is presented to obtain one analytical solution.

Branajaya, Romi Triaji

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Modeling and discretization errors in large eddy simulations of hydrodynamic and magnetohydrodynamic channel flows  

Science Conference Proceedings (OSTI)

We assess the performances of three different subgrid scale models in large eddy simulations (LES) of turbulent channel flows. Two regimes are considered: hydrodynamic and magnetohydrodynamic (i.e. in the presence of a uniform wall-normal magnetic field). ... Keywords: Channel flow, Finite-volume method, Hydrodynamic, Kinetic energy budget, Large eddy simulation, Magnetohydrodynamic, Spectral method

A. Viré; D. Krasnov; T. Boeck; B. Knaepen

2011-03-01T23:59:59.000Z

62

Large-eddy simulation of a plane reacting jet transversely injected into supersonic turbulent channel flow  

Science Conference Proceedings (OSTI)

A plane, chemically reacting jet of fuel injected through a narrow spanwise slot into supersonic and fully turbulent air flow in a channel with isothermal, parallel walls is investigated using a semi-implicit large-eddy simulation technique. It is based ... Keywords: high-order numerical schemes, infinitely fast chemistry, large-eddy simulation, plane jet in crossflow, supersonic turbulent channel flow

Ch. Schaupp; R. Friedrich

2010-12-01T23:59:59.000Z

63

UNSTEADY SIMULATION OF FLOW IN MICRO VERTICAL AXIS WIND TURBINE  

E-Print Network (OSTI)

Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle’s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied.

A. C. Bayeul-lainé; G. Bois

2013-01-01T23:59:59.000Z

64

Numerical simulation of turbulent flow in complex geometries used in power plants  

Science Conference Proceedings (OSTI)

Performance degradations or improvements of coal-fired power stations depend on effective functioning of pulveriser equipment and combustion efficiency of furnaces in boilers. The function of a pulveriser is to grind the lumped coal and transfer the ... Keywords: CFD, coal fired power station, flow simulation, geometrical modelling, grid generation, particle trajectories, pulveriser, roller mill, turbulent flow, two-phase flow

C. Bhasker

2002-02-01T23:59:59.000Z

65

On enhanced non-linear free surface flow simulations with a hybrid LBM-VOF model  

Science Conference Proceedings (OSTI)

In this paper, we present extensions, extensive validations and applications of our previously published hybrid volume-of-fluid-based (VOF) model for the simulation of free-surface flow problems. For the solution of the flow field, the lattice Boltzmann ... Keywords: Free surface, Lattice Boltzmann method, PLIC, Plunging breaker, Potential flow, Volume of fluid

Christian F. JaníEn; Stephan T. Grilli; Manfred Krafczyk

2013-01-01T23:59:59.000Z

66

Evaluation of numerical strategies for large eddy simulation of particulate two-phase recirculating flows  

Science Conference Proceedings (OSTI)

Predicting particle dispersion in recirculating two-phase flows is a key issue for reacting flows and a potential application of large eddy simulation (LES) methods. In this study, Euler/Euler and Euler/Lagrange LES approaches are compared in the bluff ... Keywords: Euler/Euler, Euler/Lagrange, LES, Particles, Two-phase recirculating flows

E. Riber; V. Moureau; M. García; T. Poinsot; O. Simonin

2009-01-01T23:59:59.000Z

67

A robust, colocated, implicit algorithm for direct numerical simulation of compressible, turbulent flows  

Science Conference Proceedings (OSTI)

A non-dissipative, robust, implicit algorithm is proposed for direct numerical and large-eddy simulation of compressible turbulent flows. The algorithm addresses the problems caused by low Mach numbers and under-resolved high Reynolds numbers. It colocates ... Keywords: All-Mach number, Compressible turbulence, Direct numerical simulation, Discrete energy conservation, Large-eddy simulation, Non-dissipative

Yucheng Hou; Krishnan Mahesh

2005-05-01T23:59:59.000Z

68

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

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

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry PI Name: William George PI Email: wgeorge@nist.gov Institution: National Institute of Standards and Technology Allocation Program: INCITE Allocation Hours at ALCF: 22 Million Year: 2012 Research Domain: Materials Science Flow properties of large-particle suspensions, such as concrete, cannot now be measured accurately in industrial settings. Flow simulations with many thousands of particles with a wide range of sizes and shapes in a non-Newtonian fluid matrix will enable the design of rheometers that will revolutionize the use of these instruments. The project's previous three-year INCITE award, granted in 2008, gave

69

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,with fluid and heat flow in fractured porous media arefluid and heat flow in porous media, heat pipe, reservoir simulation, fractured

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

70

Numerical Simulation of Liquid Metal Flows under the Influence of ...  

Science Conference Proceedings (OSTI)

A Coupled CFD-Thermodynamic-Kinetic Model to Simulate a Gas Stirred Ladle ... Exercise on Thermal and Thermosolutal Natural Convection in Liquid Alloys.

71

A survey of data resources for simulating patient flows in healthcare delivery systems  

Science Conference Proceedings (OSTI)

Modeling and simulation studies of patient flows in healthcare systems have been reported consistently in these Proceedings for over a decade. Our ongoing research in this area is motivated by our desire to develop models which will illuminate ...

K. Preston White, Jr.

2005-12-01T23:59:59.000Z

72

Simulation and visualization of fields and energy flows in electric circuits with idealized geometries  

E-Print Network (OSTI)

This thesis develops a method to simulate and visualize the fields and energy flows in electric circuits, using a simplified physical model based on an idealized geometry. The physical models combine and extend previously ...

Ohannessian, Mesrob I., 1981-

2005-01-01T23:59:59.000Z

73

Numerical Simulation of Nocturnal Drainage Flows in Idealized Valley–Tributary Systems  

Science Conference Proceedings (OSTI)

Numerical simulations of nocturnal drainage flow and transport in idealized valley–tributary systems are compared with the Atmospheric Science in Complex Terrain (ASCOT) meteorological field data and tracer studies from the Brush Creek valley of ...

Lance B. O’Steen

2000-11-01T23:59:59.000Z

74

Multiscale simulations of blood-flow: from a platelet to an artery  

Science Conference Proceedings (OSTI)

We review our recent advances on multiscale modeling of blood flow including blood rheology. We focus on the objectives, methods, computational complexity and overall methodology for simulations at the level of glycocalyx (visualization, parallel computing, task parallelism

Leopold Grinberg; Mingge Deng; Huan Lei; Joseph A. Insley; George Em Karniadakis

2012-07-01T23:59:59.000Z

75

Simulation of measuring bottom quark flow in heavy ion collisions using the CMS detector  

E-Print Network (OSTI)

In this thesis, I carried out a simulation study to characterize the measurement of bottom quark flow in relativistic Pb+Pb collisions using the Compact Muon Solenoid experiment. The Hydjet event generator is used to produce ...

Franke, Arthur James

2007-01-01T23:59:59.000Z

76

Explicit Filtering and Reconstruction Turbulence Modeling for Large-Eddy Simulation of Neutral Boundary Layer Flow  

Science Conference Proceedings (OSTI)

Standard turbulence closures for large-eddy simulations of atmospheric flow based on finite-difference or finite-volume codes use eddy-viscosity models and hence ignore the contribution of the resolved subfilter-scale stresses. These eddy-...

Fotini Katopodes Chow; Robert L. Street; Ming Xue; Joel H. Ferziger

2005-07-01T23:59:59.000Z

77

Simulations of Supercritical Flow around Points and Capes in a Coastal Atmosphere  

Science Conference Proceedings (OSTI)

Fully 3D nonlinear model simulations for supercritical flow along locations at the California coast, at Cape Mendocino, and Point Sur, are presented. The model results are objectively and subjectively verified against measurements from the ...

Michael Tjernström; Branko Grisogono

2000-01-01T23:59:59.000Z

78

Stratified Flow over Two-Dimensional Topography in Fluid of Infinite Depth: A Laboratory Simulation  

Science Conference Proceedings (OSTI)

This paper describes some laboratory experiments with two-dimensional stratified flow over isolated topography, in which a novel configuration simulating a radiating upper boundary condition is employed. Several experimental tests show that the ...

Peter G. Baines; Klaus P. Hoinka

1985-08-01T23:59:59.000Z

79

Direct Numerical Simulation Of Solidification Microstructures Affected By Fluid Flow  

E-Print Network (OSTI)

The effects of fluid flow on the solidification morphology of pure materials and solute microsegregation patterns of binary alloys are studied using a computational methodology based on a front tracking/finite difference method. A general single-field formulation is presented for the full coupling of phase change, fluid flow, heat and solute transport. This formulation accounts for interfacial rejection/absorption of latent heat and solute, interfacial anisotropies, discontinuities in material properties between the liquid and solid phases, shrinkage/expansion upon solidification and motion and deformation of the solid. Numerical results are presented for the two-dimensional dendritic solidification of pure succinonitrile and the solidification of globulitic grains of a Plutonium-Gallium alloy. For both problems, comparisons are made between solidification without fluid flow and solidification within a shear flow. Introduction Nearly all materials of engineering interest have, at som...

Damir Juric

1998-01-01T23:59:59.000Z

80

Towards multiscale simulation of moist flows with soundproof equations  

Science Conference Proceedings (OSTI)

This paper discusses incorporation of phase changes of the water substance that accompany moist atmospheric flows into the all-scale atmospheric model based on soundproof equations. Specific issue concerns developing a theoretical basis and ...

Marcin J. Kurowski; Wojciech W. Grabowski; Piotr K. Smolarkiewicz

Note: This page contains sample records for the topic "flow simulation assisted" 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.


81

Fictitious boundary and moving mesh methods for the numerical simulation of rigid particulate flows  

Science Conference Proceedings (OSTI)

In this paper, we investigate the numerical simulation of particulate flows using a new moving mesh method combined with the multigrid fictitious boundary method (FBM) [S. Turek, D.C. Wan, L.S. Rivkind, The fictitious boundary method for the implicit ... Keywords: ALE, FEM, Fictitious boundary, Moving mesh, Multigrid, Particulate flows

Decheng Wan; Stefan Turek

2007-03-01T23:59:59.000Z

82

Steam generators two phase flows numerical simulation with liquid and gas momentum equations  

E-Print Network (OSTI)

Steam generators two phase flows numerical simulation with liquid and gas momentum equations M dimensional two-phase (liquid and gas) flows. The main goal is to improve the mod- eling of kinetic imbalance between the phases. We present a method that solves the mix- ture (liquid-gas) mass and enthalpy equations

Paris-Sud XI, Université de

83

SPH Simulation of transition to turbulence for planar shear flow subjected to a streamwise magnetic field  

Science Conference Proceedings (OSTI)

Active flow control of electrically conducting fluids finds growing importance in the metallurgical industry. A magnetic field applied in the streamwise direction of electrically conducting fluid flow restrains the velocity fluctuations in the transverse ... Keywords: CFD, magnetohydrodynamics, simulation, smoothed particle hydrodynamics, turbulence control

Fangming Jiang; Mónica S. A. Oliveira; Antonio C. M. Sousa

2006-09-01T23:59:59.000Z

84

An energy preserving formulation for the simulation of multiphase turbulent flows  

Science Conference Proceedings (OSTI)

In this manuscript we propose an energy preserving formulation for the simulation of multiphase flows. The new formulation reduces the numerical diffusion with respect to previous formulations dealing with multiple phases, which makes this method to ... Keywords: Advection scheme, Multiphase flows, Turbulence

D. Fuster

2013-02-01T23:59:59.000Z

85

Accelerating moderately stiff chemical kinetics in reactive-flow simulations using GPUs  

Science Conference Proceedings (OSTI)

The chemical kinetics ODEs arising from operator-split reactive-flow simulations were solved on GPUs using explicit integration algorithms. Nonstiff chemical kinetics of a hydrogen oxidation mechanism (9 species and 38 irreversible reactions) were computed ... Keywords: CUDA, Chemical kinetics, GPU, Reactive-flow modeling, Stiff chemistry

Kyle E. Niemeyer, Chih-Jen Sung

2014-01-01T23:59:59.000Z

86

Numerical simulation of three-phase flow in heterogeneous porous media  

Science Conference Proceedings (OSTI)

We describe an efficient numerical simulator, based on an operator splitting technique, for three-phase flow in heterogeneous porous media that takes into account capillary forces, general relations for the relative permeability functions and variable ... Keywords: central difference scheme, mixed finite elements, non-classical waves, operator splitting, porous media, three-phase flow

Eduardo Abreu; Frederico Furtado; Felipe Pereira

2006-06-01T23:59:59.000Z

87

Numerical Simulations of the Effects of Seamounts and Vertical Resolution on Strong Ocean Flows  

Science Conference Proceedings (OSTI)

The effect of seamounts on Gulf Stream-like flow is examined using a quasi-geostrophic modal model that is spun-up from rest with idealized wind forcing. A flat-bottom simulation that resolves the flow with two vertical modes produces, on the ...

David Adamec

1988-02-01T23:59:59.000Z

88

AMG for linear systems in engine flow simulations  

Science Conference Proceedings (OSTI)

The performance of three fundamentally different AMG solvers for systems of linear equations in CFD simulations using SIMPLE and PISO algorithm is examined. The presented data is discussed with respect to computational aspects of the parallelisation. ...

Maximilian Emans

2009-09-01T23:59:59.000Z

89

Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple GPUs  

E-Print Network (OSTI)

8 Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple Compounds A Large-scale Simulation on CFD in Construction Industry Estimation of strong ground motion and manufacturing of plumbing products such as ceramic sanitary wares. In order to re-produce the complex

90

Hybrid atomistic-continuum method for the simulation of dense fluid flows  

Science Conference Proceedings (OSTI)

We present a hybrid atomistic-continuum method for multiscale simulations of dense fluids. In this method, the atomistic part is described using a molecular dynamics description, while the continuum flow is described by a finite volume discretization ... Keywords: Hybrid algorithms, Molecular dynamics, Multiscale simulation, Nanofluidics

Thomas Werder; Jens H. Walther; Petros Koumoutsakos

2005-05-01T23:59:59.000Z

91

Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation  

E-Print Network (OSTI)

Polymer melts represent the flow-history-dependent behavior. To clearly show this behavior, we have investigated flow behavior of an entangled polymer melt around two cylinders placed in tandem along the flow direction in a two dimensional periodic system. In this system, the polymer states around a cylinder in downstream side are different from the ones around another cylinder in upstream side because the former ones have a memory of a strain experienced when passing around the cylinder in upstream side but the latter ones do not have the memory. Therefore, the shear stress distributions around two cylinders are found to be different from each other. Moreover, we have found that the averaged flow velocity decreases accordingly with increasing the distance between two cylinders while the applied external force is constant. While this behavior is consistent with that of the Newtonian fluid, the flow-history-dependent behavior enhances the reduction of the flow resistance.

Takahiro Murashima; Takashi Taniguchi

2011-10-05T23:59:59.000Z

92

Numerical Simulation of Drainage Flow in Brush Creek, Colorado  

Science Conference Proceedings (OSTI)

One of the objectives of the Atmospheric Studies in Complex Terrain (ASCOT) program is to develop numerical models that can be used to aid in the understanding and prediction of flow patterns observed over complex terrain. As part of this program,...

John M. Leone Jr.; Robert L. Lee

1989-06-01T23:59:59.000Z

93

Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow  

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

Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. This picture highlights the root and tip vortex along with the turbulent structures in the wake of a deflected rudder through isosurface of instantaneous Q criterion colored by speed on a locally adapted unstructured finite element mesh with 1.2 billion elements. Michel Rasquin, Argonne National Laboratory Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF:

94

Design of Triple Swirler and Simulation of its Flow Field  

Science Conference Proceedings (OSTI)

This paper presents an analysis of triple swirler design essentials. UG software is used to establish the geometry model of the model combustor with a triple swirler. The grid calculation model is generated using tetrahedral unstructured meshing method. ... Keywords: gas turbine, combustor, numerical simulation, triple swirler

Wang Chengjun; Wu Zhengyu; Wang Dan-dan; Zhang Qunjie

2011-01-01T23:59:59.000Z

95

Magnetohydrodynamic lattice Boltzmann simulations of turbulence and rectangular jet flow  

E-Print Network (OSTI)

Magnetohydrodynamic (MHD) investigations of decaying isotropic turbulence and rectangular jets (RJ) are carried out. A novel MHD lattice Boltzmann scheme that combines multiple relaxation time (MRT) parameters for the velocity field with a single relaxation time (SRT) parameter for the Maxwell’s stress tensor is developed for this study. In the MHD homogeneous turbulence studies, the kinetic/magnetic energy and enstrophy decays, kinetic enstrophy evolution, and vorticity alignment with the strain-rate tensor are evaluated to assess the key physical MHD turbulence mechanisms. The magnetic and kinetic energies interact and exchange through the influence of the Lorentz force work. An initial random fluctuating magnetic field increases the vortex stretching and forward cascade mechanisms. A strong uniform mean magnetic field increases the anisotropy of the turbulent flow field and causes inverse cascading. In the RJ studies, an investigation into the MHD effects on velocity, instability, and the axis-switching phenomena is performed at various magnetic field strengths and Magnetic Reynolds Numbers. The magnetic field is found to decelerate the jet core, inhibit instability, and prevent axis-switching. The key physical mechanisms are: (i) the exchange of energy between kinetic and magnetic modes and (ii) the magnetic field effect on the vorticity evolution. From these studies, it is found that magnetic field influences momentum, vorticity, and energy evolution and the degree of modification depends on the field strength. This interaction changes vortex evolution, and alters turbulence processes and rectangular jet flow characteristics. Overall, this study provides more insight into the physics of MHD flows, which suggests possible applications of MHD Flow Control.

Riley, Benjamin Matthew

2007-05-01T23:59:59.000Z

96

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 ... Keywords: CO2 geological storage, Environmental remediation, Multi-phase flow, Nuclear waste geological disposal, Reactive transport, TOUGHREACT

Tianfu Xu; Nicolas Spycher; Eric Sonnenthal; Guoxiang Zhang; Liange Zheng; Karsten Pruess

2011-06-01T23:59:59.000Z

97

Modeling fluid flow through single fracture using experimental, stochastic, and simulation approaches  

E-Print Network (OSTI)

This research presents an approach to accurately simulate flow experiments through a fractured core using experimental, stochastic, and simulation techniques. Very often, a fracture is assumed as a set of smooth parallel plates separated by a constant width. However, the flow characteristics of an actual fracture surface are quite different, affected by tortuosity and the impact of surface roughness. Though several researchers have discussed the effect of friction on flow reduction, their efforts lack corroboration from experimental data and have not converged to form a unified methodology for studying flow on a rough fracture surface. In this study, an integrated methodology involving experimental, stochastic, and numerical simulations that incorporate the fracture roughness and the friction factor is shown to describe flow through single fractures more efficiently. Laboratory experiments were performed to support the study in quantifying the flow contributions from the matrix and the fracture. The results were used to modify the cubic law through reservoir simulations. Observations suggest that the fracture apertures need to be distributed to accurately model the experimental results. The methodology successfully modeled fractured core experiments, which were earlier not possible using the parallel plate approach. A gravity drainage experiment using an X-ray CT scan of a fractured core has also validated the methodology.

Alfred, Dicman

2003-12-01T23:59:59.000Z

98

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

99

CFD Simulation and Experimental Testing of Multiphase Flow Inside the MVP Electrical Submersible Pump  

E-Print Network (OSTI)

The MVP is a special type of Electrical Submersible Pumps (ESPs) manufactured by Baker Hughes, model no. G470, and is capable of handling multiphase flow up to 70% Gas Volume Fraction (GVF). Flows at high GVF cause conventional ESPs to surge. However, the special design of the impeller blades of the MVP ESP enables it to handle higher GVF. Dynamic behavior of the multiphase flow is studied experimentally and theoretically for this pump for the first time. In this work, a Computational Fluid Dynamics (CFD) simulation of an entire pump and detailed experimental analysis are performed. Meshing and CFD simulations are performed using the commercially available software ANSYS Fluent. An experimental facility has been designed and constructed to test the pump at different operating conditions. The pump is modeled and tested at two speeds; 3300 and 3600 rpm, using air-water mixtures with GVFs of 0, 5, 10, 25, 32 and 35%. The flow loop is controlled to produce different suction pressures up to 300psi. Pump pressure head is used to validate the CFD model for both single and two phase flows. Single phase CFD model was validated at 100 psi inlet pressure, while two phase models were validated at 200 psi inlet pressure. CFD simulations can predict the behavior of the pump at different speeds, flow rates, GVFs, and inlet pressures. Different diffuser designs are studied and simulated to improve the multistage pump performance. Enhanced diffuser designs increased the pump pressure head to up to 3.2%.

Rasmy Marsis, Emanuel 1983-

2012-12-01T23:59:59.000Z

100

A Novel Approach For the Simulation of Multiple Flow Mechanisms and Porosities in Shale Gas Reservoirs  

E-Print Network (OSTI)

The state of the art of modeling fluid flow in shale gas reservoirs is dominated by dual porosity models that divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control flow capacity. However, recent extensive microscopic studies reveal that there exist massive micro- and nano- pore systems in shale matrices. Because of this, the actual flow mechanisms in shale reservoirs are considerably more complex than can be simulated by the conventional dual porosity models and Darcy’s Law. Therefore, a model capturing multiple pore scales and flow can provide a better understanding of complex flow mechanisms occurring in these reservoirs. Through the use of a unique simulator, this research work establishes a micro-scale multiple-porosity model for fluid flow in shale reservoirs by capturing the dynamics occurring in three separate porosity systems: organic matter (mainly kerogen); inorganic matter; and natural fractures. Inorganic and organic portions of shale matrix are treated as sub-blocks with different attributes, such as wettability and pore structures. In the organic matter or kerogen, gas desorption and diffusion are the dominant physics. Since the flow regimes are sensitive to pore size, the effects of smaller pores (mainly nanopores and picopores) and larger pores (mainly micropores and nanopores) in kerogen are incorporated in the simulator. The separate inorganic sub-blocks mainly contribute to the ability to better model dynamic water behavior. The multiple porosity model is built upon a unique tool for simulating general multiple porosity systems in which several porosity systems may be tied to each other through arbitrary transfer functions and connectivities. This new model will allow us to better understand complex flow mechanisms and in turn to extend simulation to the reservoir scale including hydraulic fractures through upscaling techniques

Yan, Bicheng

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

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

102

Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow  

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

Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF: 40 Million Year: 2012 Research Domain: Engineering The use of fuel-and its accompanying costs-has become an increasing concern in many industries. Researchers are examining the issue of fuel reduction in commercial jet aircraft from the perspective of redesign. By redesigning the vertical tail of a commercial jet, they hope to reduce jet fuel use by 0.5%, resulting in annual savings of $300 million. Using -synthetic commercial jet aircraft, the team will perform a series

103

The Instability of Long's Stationary Solution and the Evolution toward Severe Downslope Windstorm Flow. Part I: Nested Grid Numerical Simulations  

Science Conference Proceedings (OSTI)

Through direct numerical simulation, the instability of Long's exact finite-amplitude steady-state solution to the problem of stratified flow over topography and the subsequent evolution towards severe downslope windstorm flow is investigated. ...

J. F. Scinocca; W. R. Peltier

1993-07-01T23:59:59.000Z

104

High-Resolution Large-Eddy Simulations of Scalar Transport in Atmospheric Boundary Layer Flow over Complex Terrain  

Science Conference Proceedings (OSTI)

This paper presents high-resolution numerical simulations of the atmospheric flow and concentration fields accompanying scalar transport and diffusion from a point source in complex terrain. Scalar dispersion is affected not only by mean flow, ...

Takenobu Michioka; Fotini Katopodes Chow

2008-12-01T23:59:59.000Z

105

SPECTRAL ANALYSIS OF UNSTEADY FLOW SIMULATION IN A SMALL VAWT  

E-Print Network (OSTI)

The vertical axis wind turbine studied in this paper combine two rotations: one rotating movement of each blade around its own axis and one rotating movement around turbine’s axis. The aim of this paper is to analyse the effect of this two combine movements on fields of pressure and on global forces on each blade with time. Preliminary calculations showed, for some initial blade stagger angles (angle between blade 1 and x axis), that flow is highly unsteady and sometimes hardly periodic. The main goal here is to present spectral analysis of unsteady results like temporal pressure on specific points in the domain and temporal forces on blades and to show the influence of the two combine movements for two different blade stagger angles for elliptic blades.

Annie-claude Bayeul-lainé; Sophie Simonet; Gérard Bois; Leconte P; Rapin M; Szechenyi E; Martin J

2013-01-01T23:59:59.000Z

106

Numerical simulation of laminar reacting flows with complex chemistry  

SciTech Connect

We present an adaptive algorithm for low Mach number reacting flows with complex chemistry. Our approach uses a form of the low Mach number equations that discretely conserves both mass and energy. The discretization methodology is based on a robust projection formulation that accommodates large density contrasts. The algorithm uses an operator-split treatment of stiff reaction terms and includes effects of differential diffusion. The basic computational approach is embedded in an adaptive projection framework that uses structured hierarchical grids with subcycling in time that preserves the discrete conservation properties of the underlying single-grid algorithm. We present numerical examples illustrating the performance of the method on both premixed and non-premixed flames.

Day, Marcus S.; Bell, John B.

1999-12-01T23:59:59.000Z

107

Conservative numerical simulation of multi-component transport in two-dimensional unsteady shallow water flow  

Science Conference Proceedings (OSTI)

An explicit finite volume model to simulate two-dimensional shallow water flow with multi-component transport is presented. The governing system of coupled conservation laws demands numerical techniques to avoid unrealistic values of the transported ... Keywords: ?-? model, 35L65, 65M06, 65M12, 76M12, 76M20, Coupled system, Multi-component transport, Reactive source terms, Shallow flow, Solute constraints, Turbulence, Variable domain, Well-balanced approach

J. Murillo; P. García-Navarro; J. Burguete

2009-08-01T23:59:59.000Z

108

Verification of software codes for simulation of unsteady flows in a gas centrifuge  

Science Conference Proceedings (OSTI)

A simple semi-analytical solution is proposed for the problem of an unsteady gas flow in a gas centrifuge. The circulation in the centrifuge is driven by a source/sink of energy and by an external force (deceleration/acceleration of the gas rotation) ... Keywords: mathematical simulation of unsteady flows in a gas centrifuge, numerical solution of gas dynamics equations, semi-analytical solution, verification of software codes

V. A. Abramov; S. V. Bogovalov; V. D. Borisevich; V. D. Borman; V. A. Kislov; I. V. Tronin; V. N. Tronin; S. V. Yupatov

2013-06-01T23:59:59.000Z

109

Augmented Lagrangian and penalty methods for the simulation of two-phase flows interacting with moving solids. Application to hydroplaning flows interacting with real tire tread patterns  

Science Conference Proceedings (OSTI)

The numerical simulation of the interaction between a free surface flow and a moving obstacle is considered for the analysis of hydroplaning flows. A new augmented Lagrangian method, coupled to fictitious domains and penalty methods, is proposed for ... Keywords: 1-fluid model, Augmented Lagrangian, Fictitious domain, Hydroplaning flows, Patterned tire, Penalty method, Volume of fluid

Stéphane Vincent; Arthur Sarthou; Jean-Paul Caltagirone; Fabien Sonilhac; Pierre Février; Christian Mignot; Grégoire Pianet

2011-02-01T23:59:59.000Z

110

Simulation of groundwater flow at the LBNL site using TOUGH2  

SciTech Connect

In the late 1980s, groundwater contamination was detected at the site of the Lawrence Berkeley National Laboratory (LBNL). A detailed investigation was conducted to locate the source and the extent of the contamination. Interim corrective measures were initiated where appropriate and required, typically directed towards removing the source of contamination, excavating contaminated soil, and limiting further spreading of contaminants. As the first step for predicting the fate of remaining contaminants, a three-dimensional transient groundwater flow model was developed for the complex hydrogeological situation. This flow model captured strong variations in thickness, slope, and hydrogeological properties of geologic units, representative of a mountainous groundwater system with accentuated morphology. The flow model accounts for strong seasonal fluctuations in the groundwater table. Other significant factors are local recharge from leaking underground storm drains and significant water re charge from steep hills located upstream. The strong heterogeneous rock properties were calibrated using the inverse simulator ITOUGH2. For validation purposes, the model was calibrated for a time period from 1994 to 1996, and then applied to a period from 1996 to 1998. Comparison of simulated and measured water levels demonstrated that the model accurately represents the complex flow situation, including the significant seasonal fluctuations in water table and flow rate. Paths of particles originating from contaminant plumes in the simulated transient flow fields were obtained to represent advective transport.

Zhou, Quanlin; Birkholzer, Jens T.; Javandel, Iraj; Jordan, Preston D.

2003-05-12T23:59:59.000Z

111

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

grain-specific heat for each model grid layer, are providedand heat flow is simulated using the 3-D TH model grid (

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

112

A Nocturnal Atmospheric Drainage Flow Simulation Investigating the Application of One-Dimensional Modeling and Current Turbulence Schemes  

Science Conference Proceedings (OSTI)

We developed a one-dimensional boundary layer model to simulate nocturnal atmospheric drainage flow on a simple forest-covered slope using canopy, soil and radiation parameterizations from previous studies along with turbulence simulation (from ...

Warren Heilman; Ronald Dobosy

1985-09-01T23:59:59.000Z

113

Simulation analysis of within-day flow fluctuation effects on trout below flaming Gorge Dam.  

DOE Green Energy (OSTI)

In addition to being renewable, hydropower has the advantage of allowing rapid load-following, in that the generation rate can easily be varied within a day to match the demand for power. However, the flow fluctuations that result from load-following can be controversial, in part because they may affect downstream fish populations. At Flaming Gorge Dam, located on the Green River in northeastern Utah, concern has been raised about whether flow fluctuations caused by the dam disrupt feeding at a tailwater trout fishery, as fish move in response to flow changes and as the flow changes alter the amount or timing of the invertebrate drift that trout feed on. Western Area Power Administration (Western), which controls power production on submonthly time scales, has made several operational changes to address concerns about flow fluctuation effects on fisheries. These changes include reducing the number of daily flow peaks from two to one and operating within a restricted range of flows. These changes significantly reduce the value of the power produced at Flaming Gorge Dam and put higher load-following pressure on other power plants. Consequently, Western has great interest in understanding what benefits these restrictions provide to the fishery and whether adjusting the restrictions could provide a better tradeoff between power and non-power concerns. Directly evaluating the effects of flow fluctuations on fish populations is unfortunately difficult. Effects are expected to be relatively small, so tightly controlled experiments with large sample sizes and long study durations would be needed to evaluate them. Such experiments would be extremely expensive and would be subject to the confounding effects of uncontrollable variations in factors such as runoff and weather. Computer simulation using individual-based models (IBMs) is an alternative study approach for ecological problems that are not amenable to analysis using field studies alone. An IBM simulates how a population responds to environmental changes by representing how the population's individuals interact with their environment and each other. IBMs represent key characteristics of both individual organisms (trout, in this case) and the environment, thus allowing controlled simulation experiments to analyze the effects of changes in the key variables. For the flow fluctuation problem at Flaming Gorge Dam, the key environmental variables are flow rates and invertebrate drift concentrations, and the most important processes involve how trout adapt to changes (over space and time) in growth potential and mortality risk. This report documents simulation analyses of flow fluctuation effects on trout populations. The analyses were conducted in a highly controlled fashion: an IBM was used to predict production (survival and growth) of trout populations under a variety of scenarios that differ only in the level or type of flow fluctuation.

Railsback, S. F.; Hayse, J. W.; LaGory, K. E.; Environmental Science Division; EPRI

2006-01-01T23:59:59.000Z

114

Development of the T+M coupled flow-geomechanical simulator to describe fracture propagation and coupled flow-thermal-geomechanical processes in tight/shale gas systems  

Science Conference Proceedings (OSTI)

We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, ... Keywords: Double porosity, Fracture propagation, Hydraulic fracturing, Poromechanics, Shale gas, Tensile failure

Jihoon Kim, George J. Moridis

2013-10-01T23:59:59.000Z

115

Free-surface flow simulations for discharge-based operation of hydraulic structure gates  

E-Print Network (OSTI)

We combine non-hydrostatic flow simulations of the free surface with a discharge model based on elementary gate flow equations for decision support in operation of hydraulic structure gates. A water level-based gate control used in most of today's general practice does not take into account the fact that gate operation scenarios producing similar total discharged volumes and similar water levels may have different local flow characteristics. Accurate and timely prediction of local flow conditions around hydraulic gates is important for several aspects of structure management: ecology, scour, flow-induced gate vibrations and waterway navigation. The modelling approach is described and tested for a multi-gate sluice structure regulating discharge from a river to the sea. The number of opened gates is varied and the discharge is stabilized with automated control by varying gate openings. The free-surface model was validated for discharge showing a correlation coefficient of 0.994 compared to experimental data. A...

Erdbrink, C D; Sloot, P M A

2012-01-01T23:59:59.000Z

116

Numerical simulation of transient gas flow during underbalanced drilling into a gas sand  

Science Conference Proceedings (OSTI)

Shallow gas drilling has long been recognized as a serious problem in offshore operations. Low fracture gradients and shallow casing do not permit shutting- in the well. Computer simulations of gas kicks during drilling require accurate description of the gas flow rate from the formation into the wellbore. The problem is complicated by the fact that during drilling into a gas sand the effective wellbore area exposed to flow is continually changing until the formation has been completely drilled. This paper describes a numerical model developed to calculate gas flow into the wellbore while drilling underbalanced into a gas sand. A two-dimensional finite difference model of transient flow from the reservoir has been coupled with a one-dimensional finite element model of two-phase flow in the wellbore.

Berg, K.A.; Skalle, P. (Dept. of Petroleum Engineering, Univ. of Trondheim (NO)); Podio, A.L. (Dept. of Petroleum Engineering, Univ. of Texas at Austin, Austin, TX (US))

1991-01-01T23:59:59.000Z

117

Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows  

SciTech Connect

Gas-particle flows in fluidized beds and riser reactors are inherently unstable, and they manifest fluctuations over a wide range of length and time scales. Two-fluid models for such flows reveal unstable modes whose length scale is as small as ten particle diameters. Yet, because of limited computational resources, gas-particle flows in large fluidized beds are invariably simulated by solving discretized versions of the two-fluid model equations over a coarse spatial grid. Such coarse-grid simulations do not resolve the small-scale spatial structures which are known to affect the macroscale flow structures both qualitatively and quantitatively. Thus there is a need to develop filtered two-fluid models which are suitable for coarse-grid simulations and capturing the effect of the small-scale structures through closures in terms of the filtered variables. The overall objective of the project is to develop validated closures for filtered two-fluid models for gas-particle flows, with the transport gasifier as a primary, motivating example. In this project, highly resolved three-dimensional simulations of a kinetic theory based two-fluid model for gas-particle flows have been performed and the statistical information on structures in the 100-1000 particle diameters length scale has been extracted. Based on these results, closures for filtered two-fluid models have been constructed. The filtered model equations and closures have been validated against experimental data and the results obtained in highly resolved simulations of gas-particle flows. The proposed project enables more accurate simulations of not only the transport gasifier, but also many other non-reacting and reacting gas-particle flows in a variety of chemical reactors. The results of this study are in the form of closures which can readily be incorporated into existing multi-phase flow codes such as MFIX (www.mfix.org). Therefore, the benefits of this study can be realized quickly. The training provided by this project has prepared a PhD student to enter research and development careers in DOE laboratories or chemicals/energy-related industries.

Sankaran Sundaresan

2010-02-14T23:59:59.000Z

118

Short-circuit simulations help quantify wheeling flow  

SciTech Connect

During the late 1960s, three nuclear power plants were constructed in New England: Connecticut Yankee (590 MW, located in Haddam, Connecticut), Maine Yankee (870 MW located in Wiscasset, Maine), and Vermont Yankee (520 MW, located in Vernon, Vermont). Up to thirty-three New England utilities and municipalities participate in each. These units, called the Yankee units, are connected to the New England 345 kV transmission system. Built before the conception of the New England Power Pool (NEPOOL), these units rely on negotiated transmission agreements to implement the purchased power contracts. The Yankee Transmission Agreements were established to provide a mechanism for New England utilities, which provide the transmission wheeling services, to be adequately compensated for delivering the Yankee power. Under the agreements, the purchasing utilities (those utilities who purchase power from the nuclear plants) would pay into separate transmission funds based on their entitlement in the unit. The fund is then distributed among the transmitting utilities (those utilities providing the transmission wheeling services) based on the calculated use of their transmission systems. A methodology was established that could equal the units` life, offer flexibility to a changing system, and provide equitable results. This article describes how using commercially available software to automate simulations, perform the MW-miles calculation, and tabulate the results significantly reduces the time and computational effort to perform the wheeling calculations.

Scarfone, A.

1995-04-01T23:59:59.000Z

119

Flow simulation of the Component Development Integration Facility magnetohydrodynamic power train system  

DOE Green Energy (OSTI)

This report covers application of Argonne National Laboratory`s (ANL`s) computer codes to simulation and analysis of components of the magnetohydrodynamic (MHD) power train system at the Component Development and Integration Facility (CDIF). Major components of the system include a 50-MWt coal-fired, two-stage combustor and an MHD channel. The combustor, designed and built by TRW, includes a deswirl section between the first and the second-stage combustor and a converging nozzle following the second-stage combustor, which connects to the MHD channel. ANL used computer codes to simulate and analyze flow characteristics in various components of the MHD system. The first-stage swirl combustor was deemed a mature technology and, therefore, was not included in the computer simulation. Several versions of the ICOMFLO computer code were used for the deswirl section and second-stage combustor. The MGMHD code, upgraded with a slag current leakage submodel, was used for the MHD channel. Whenever possible data from the test facilities were used to aid in calibrating parameters in the computer code, to validate the computer code, or to set base-case operating conditions for computations with the computer code. Extensive sensitivity and parametric studies were done on cold-flow mixing in the second-stage combustor, reacting flow in the second-stage combustor and converging nozzle, and particle-laden flow in the deswirl zone of the first-stage combustor, the second-stage combustor, and the converging nozzle. These simulations with subsequent analysis were able to show clearly in flow patterns and various computable measures of performance a number of sensitive and problematical areas in the design of the power train. The simulations of upstream components also provided inlet parameter profiles for simulation of the MHD power generating channel. 86 figs., 18 tabs.

Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

1997-11-01T23:59:59.000Z

120

Reactive Flow Modeling of Liquid Explosives via ALE3D/Cheetah Simulations  

SciTech Connect

We carried out reactive flow simulations of liquid explosives such as nitromethane using the hydrodynamic code ALE3D coupled with equations of state and reaction kinetics modeled by the thermochemical code Cheetah. The simulation set-up was chosen to mimic cylinder experiments. For pure unconfined nitromethane we find that the failure diameter and detonation velocity dependence on charge diameter are in agreement with available experimental results. Such simulations are likely to be useful for determining detonability and failure behavior for a wide range of experimental conditions and explosive compounds.

Kuo, I W; Bastea, S; Fried, L E

2010-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

An efficient multigrid-FEM method for the simulation of solid-liquid two phase flows  

Science Conference Proceedings (OSTI)

An efficient multigrid-FEM method for the detailed simulation of solid-liquid two phase flows with large number of moving particles is presented. An explicit fictitious boundary method based on a FEM background grid which covers the whole computational ... Keywords: 65K99, 65M55, 65N55, Fictitious boundary method, Multigrid FEM, Solid-liquid two phase

Decheng Wan; Stefan Turek

2007-06-01T23:59:59.000Z

122

Algorithm for direct numerical simulation of emulsion flow through a granular material  

Science Conference Proceedings (OSTI)

A multipole-accelerated 3D boundary-integral algorithm capable of modelling an emulsion flow through a granular material by direct multiparticle-multidrop simulations in a periodic box is developed and tested. The particles form a random arrangement ... Keywords: Deformable drop, Emulsion, Granular material, Multipole

Alexander Z. Zinchenko; Robert H. Davis

2008-08-01T23:59:59.000Z

123

Numerical Simulation of Late Wintertime Local Flows in Kathmandu Valley, Nepal: Implication for Air Pollution Transport  

Science Conference Proceedings (OSTI)

Air pollution transport in the Kathmandu valley/basin has been investigated by numerical simulation of local flows and the observation of NO2 and SO2. The observation was performed at 22 sites with passive samplers from February to April 2001, ...

Ram P. Regmi; Toshihiro Kitada; Gakuji Kurata

2003-03-01T23:59:59.000Z

124

Simulations of transonic shock-tube flow with a model micro-cylinder in the driver  

Science Conference Proceedings (OSTI)

A unique hand-held needle-free powder injection system, using a transient shock-tube flow to deliver powder genes and drugs into human skin for a wide range of treatments, has been proposed. In the development of such devices, a strong non-linear phenomenon, ... Keywords: Laminar, Separation, Shock-tube, Simulation, Transition, Turbulence

Yi Liu; Mark A. F. Kendall

2007-02-01T23:59:59.000Z

125

Prediction and Analysis of Rotor Tip-Clearance Flows using Large-Eddy Simulation  

Science Conference Proceedings (OSTI)

In order to analyze the dynamics of rotor tip-clearance flow and determine the underlying mechanism for the tip-leakage cavitation, a newly developed large-eddy simulation (LES) solver which combines an immersed-boundary method with a generalized curvilinearstructured ...

Donghyun You; Meng Wang; Parviz Moin; Rajat Mittal

2004-06-01T23:59:59.000Z

126

Three-dimensional simulation of elastic capsules in shear flow by the penalty immersed boundary method  

Science Conference Proceedings (OSTI)

An improved penalty immersed boundary method (pIBM) has been proposed for simulation of flow-induced deformation of three-dimensional (3D) elastic capsules. The motion of the capsule membrane is described in the Lagrangian coordinates. The membrane deformation ... Keywords: Elastic capsule, Fluid-structure interaction, Penalty immersed boundary method, Red blood cell, Subdivision surface

Wei-Xi Huang; Cheong Bong Chang; Hyung Jin Sung

2012-04-01T23:59:59.000Z

127

Low-Level Jet Development during a Numerically Simulated Return Flow Event  

Science Conference Proceedings (OSTI)

The evolution of the southerly low-level jet (LLJ) during a return flow event is studied using output from the Penn State/NCAR Mesoscale Model (Version 4). Three geographically different southerly LLJs develop in the simulation: one over the ...

Richard C. Igau; John W. Nielsen-Gammon

1998-11-01T23:59:59.000Z

128

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

129

Simulation of water flow and solute transport in free-drainage lysimeters and field soils with  

E-Print Network (OSTI)

Simulation of water flow and solute transport in free-drainage lysimeters and field soils with heterogeneous structures H. M. ABDOU & M. FLURY Department of Crop and Soil Sciences, Center for Multiphase for studying the fate and transport of chemicals in soil. Large-scale field lysimeters are used to assess

Flury, Markus

130

Coupling geological and numerical models to simulate groundwater flow and contaminant transport in fractured media  

Science Conference Proceedings (OSTI)

A new modeling approach is presented to improve numerical simulations of groundwater flow and contaminant transport in fractured geological media. The approach couples geological and numerical models through an intermediate mesh generation phase. As ... Keywords: Fractures, Geomodel, Influence coefficient technique, Numerical modeling, Tetrahedra

Daniela Blessent; René Therrien; Kerry MacQuarrie

2009-09-01T23:59:59.000Z

131

Non-isothermal, compressible gas flow for the simulation of an enhanced gas recovery application  

Science Conference Proceedings (OSTI)

In this work, we present a framework for numerical modeling of CO"2 injection into porous media for enhanced gas recovery (EGR) from depleted reservoirs. Physically, we have to deal with non-isothermal, compressible gas flows resulting in a system of ... Keywords: Carbon dioxide sequestration, Enhanced gas recovery, Equation of state, Finite element method, Numerical simulation, Real gas behavior

N. BöTtcher; A. -K. Singh; O. Kolditz; R. Liedl

2012-12-01T23:59:59.000Z

132

Wind flow modeling and simulation over the Giza Plateau cultural heritage site in Egypt  

Science Conference Proceedings (OSTI)

In this article, the wind flow over one of the most important Egyptian historical heritage sites, the Giza Plateau, was investigated using the Computational Fluid Dynamics (CFD) state-of-the-art techniques. The present study addresses the influences ... Keywords: Cultural heritage, Giza Plateau, Great Sphinx, computational fluid dynamics, wind modeling and simulation, wind over heritage sites

Ashraf S. Hussein; Hisham El-Shishiny

2009-11-01T23:59:59.000Z

133

Stratospheric Flow during Two Recent Winters Simulated by a Mechanistic Model  

Science Conference Proceedings (OSTI)

The authors have used a spectral, primitive equation mechanistic model of the stratosphere and mesosphere to simulate observed stratospheric flow through the winters of 1991–92 and 1994–95 by forcing the model at 100 hPa with observed ...

Philip W. Mote; Peter A. Stott; Robert S. Harwood

1998-06-01T23:59:59.000Z

134

Large-Eddy Simulation of Flow over Two-Dimensional Obstacles: High Drag States and Mixing  

Science Conference Proceedings (OSTI)

A three-dimensional large-eddy simulation (LES) model was used to examine how stratified flow interacts with bottom obstacles in the coastal ocean. Bottom terrain representing a 2D ridge was modeled using a finite-volume approach with ridge ...

Eric D. Skyllingstad; Hemantha W. Wijesekera

2004-01-01T23:59:59.000Z

135

Numerical simulation of flow distribution for pebble bed high temperature gas cooled reactors  

E-Print Network (OSTI)

The premise of the work presented here is to use a common analytical tool, Computational Fluid dynamics (CFD), along with a difference turbulence models. Eddy viscosity models as well as state-of-the-art Large Eddy Simulation (LES) were used to study the flow past bluff bodies. A suitable CFD code (CFX5.6b) was selected and implemented. Simulation of turbulent transport for the gas through the gaps of the randomly distributed spherical fuel elements (pebbles) was performed. Although there are a number of numerical studies () on flows around spherical bodies, none of them use the necessary turbulence models that are required to simulate flow where strong separation exists. With the development of high performance computers built for applications that require high CPU time and memory; numerical simulation becomes one of the more effective approaches for such investigations and LES type of turbulence models can be used more effectively. Since there are objects that are touching each other in the present study, a special approach was applied at the stage of building computational domain. This is supposed to be a considerable improvement for CFD applications. Zero thickness was achieved between the pebbles in which fission reaction takes place. Since there is a strong pressure gradient as a result of high Reynolds Number on the computational domain, which strongly affects the boundary layer behavior, heat transfer in both laminar and turbulent flows varies noticeably. Therefore, noncircular curved flows as in the pebble-bed situatio n, in detailed local sense, is interesting to be investigated. Since a compromise is needed between accuracy of results and time/cost of effort in acquiring the results numerically, selection of turbulence model should be done carefully. Resolving all the scales of a turbulent flow is too costly, while employing highly empirical turbulence models to complex problems could give inaccurate simulation results. The Large Eddy Simulation (LES) method would achieve the requirements to obtain a reasonable result. In LES, the large scales in the flow are solved and the small scales are modeled. Eddy viscosity and Reynolds stress models were also be used to investigate the applicability of these models for this kind of flow past bluff bodies at high Re numbers.

Yesilyurt, Gokhan

2006-05-01T23:59:59.000Z

136

Hull/Mooring/Riser coupled motion simulations of thruster-assisted moored platforms  

E-Print Network (OSTI)

To reduce large motion responses of moored platforms in a harsh environment in deep waters, a thruster-assisted position mooring system can be applied. By applying the system, global dynamic responses can be improved in terms of the mooring line/riser top tensions, operational radii, and the top and bottom angle of the production risers. Kalman filtering as an optimum observer and estimator for stochastic disturbances is implemented in the developed control algorithm to filter out wave frequency responses. Investigation of the performance of thruster-assisted moored offshore platforms was conducted in terms of six-degree-of-freedom motions and mooring line/riser top tensions by means of a fully coupled hull/mooring/riser dynamic analysis program in the time domain and a spectral analysis. The two cases, motion analyses of a platform with thrusters and without thrusters, are extensively compared. The numerical examples illustrate that for deepwater position-keeping of platforms a thruster-assisted moored platform can be an effective solution compared to a conventionally moored platform.

Ryu, Sangsoo

2003-12-01T23:59:59.000Z

137

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

Science Conference Proceedings (OSTI)

This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC^3^D geomechanical ... Keywords: FLAC3D, Fluid flow, Geomechanics, Modeling, TOUGH

Jonny Rutqvist

2011-06-01T23:59:59.000Z

138

TOUGH+CO2: A multiphase fluid-flow simulator for CO2 geologic sequestration in saline aquifers  

Science Conference Proceedings (OSTI)

TOUGH+CO"2 is a new simulator for modeling of CO"2 geologic sequestration in saline aquifers. It is a member of TOUGH+, the successor to the TOUGH2 family of codes for multicomponent, multiphase fluid and heat flow simulation. The code accounts for heat ... Keywords: CO2 geologic sequestration, Modeling, Multiphase flow, Parallel computing, Saline aquifer, TOUGH+, TOUGH2

Keni Zhang; George Moridis; Karsten Pruess

2011-06-01T23:59:59.000Z

139

Adaptive and Efficient Computing for Subsurface Simulation within ParFlow  

SciTech Connect

This project is concerned with the PF.WRF model as a means to enable more accurate predictions of wind fluctuations and subsurface storage. As developed at LLNL, PF.WRF couples a groundwater (subsurface) and surface water flow model (ParFlow) to a mesoscale atmospheric model (WRF, Weather Research and Forecasting Model). It was developed as a unique tool to address coupled water balance and wind energy questions that occur across traditionally separated research regimes of the atmosphere, land surface, and subsurface. PF.WRF is capable of simulating fluid, mass, and energy transport processes in groundwater, vadose zone, root zone, and land surface systems, including overland flow, and allows for the WRF model to both directly drive and respond to surface and subsurface hydrologic processes and conditions. The current PF.WRF model is constrained to have uniform spatial gridding below the land surface and matching areal grids with the WRF model at the land surface. There are often cases where it is advantageous for land surface, overland flow and subsurface models to have finer gridding than their atmospheric counterparts. Finer vertical discretization is also advantageous near the land surface (to properly capture feedbacks) yet many applications have a large vertical extent. However, the surface flow is strongly dependent on topography leading to a need for greater lateral resolution in some regions and the subsurface flow is tightly coupled to the atmospheric model near the surface leading to a need for finer vertical resolution. In addition, the interactions (e.g. rain) will be highly variable in space and time across the problem domain so an adaptive scheme is preferred to a static strategy to efficiently use computing and memory resources. As a result, this project focussed on algorithmic research required for development of an adaptive simulation capability in the PF.WRF system and its subsequent use in an application problem in the Central Valley of California. This report documents schemes of use for a future implementation of an adaptive grid capability within the ParFlow subsurface flow simulator in PF.WRF. The methods describe specific handling of the coarse/fine boundaries within a cell-centered discretization of the nonlinear parabolic Richards equation model for variable saturated flow. In addition, we describe development of a spline fit and table lookup method implemented within ParFlow to enhance computational efficiency of variably saturated flow calculations.

Tiedeman, H; Woodward, C S

2010-11-16T23:59:59.000Z

140

Numerical simulation to determine the effects of incident wind shear and turbulence level on the flow around a building  

Science Conference Proceedings (OSTI)

The effects of incident shear and turbulence on flow around a cubical building are being investigated by a turbulent kinetic energy/dissipation model (TEMPEST). The numerical simulations demonstrate significant effects due to the differences in the incident flow. The addition of upstream turbulence and shear results in a reduced size of the cavity directly behind the building. The accuracy of numerical simulations is verified by comparing the predicted mean flow fields with the available wind-tunnel measurements of Castro and Robins (1977). Comparing the authors' results with experimental data, the authors show that the TEMPEST model can reasonably simulate the mean flow.

Zhang, Y.Q.; Huber, A.H.; Arya, S.P.S.; Snyder, W.H.

1992-01-01T23:59:59.000Z

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141

One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models  

DOE Green Energy (OSTI)

The activities described in this report do not constitute a continuum but rather a series of linked smaller investigations in the general area of one- and two-dimensional Stirling machine simulation. The initial impetus for these investigations was the development and construction of the Mechanical Engineering Test Rig (METR) under a grant awarded by NASA to Dr. Terry Simon at the Department of Mechanical Engineering, University of Minnesota. The purpose of the METR is to provide experimental data on oscillating turbulent flows in Stirling machine working fluid flow path components (heater, cooler, regenerator, etc.) with particular emphasis on laminar/turbulent flow transitions. Hence, the initial goals for the grant awarded by NASA were, broadly, to provide computer simulation backup for the design of the METR and to analyze the results produced. This was envisaged in two phases: First, to apply an existing one-dimensional Stirling machine simulation code to the METR and second, to adapt a two-dimensional fluid mechanics code which had been developed for simulating high Rayleigh number buoyant cavity flows to the METR. The key aspect of this latter component was the development of an appropriate turbulence model suitable for generalized application to Stirling simulation. A final-step was then to apply the two-dimensional code to an existing Stirling machine for which adequate experimental data exist. The work described herein was carried out over a period of three years on a part-time basis. Forty percent of the first year`s funding was provided as a match to the NASA funds by the Underground Space Center, University of Minnesota, which also made its computing facilities available to the project at no charge.

Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)

1990-08-01T23:59:59.000Z

142

CFD SIMULATION OF PROPOSED VALIDATION DATA FOR A FLOW PROBLEM RECONFIGURED TO ELIMINATE AN UNDESIRABLE FLOW INSTABILITY  

DOE Green Energy (OSTI)

The U. S. Department of Energy (DOE) is supporting the development of a next generation nuclear plant (NGNP), which will be based on a very high temperature reactor (VHTR) design. The VHTR is a single-phase helium-cooled reactor wherein the helium will be heated initially to 750 °C and later to temperatures approaching 1000 °C. The high temperatures are desired to increase reactor efficiency and to provide a heat source for the manufacture of hydrogen and other applications. While computational fluid dynamics (CFD) has not been used in the past to design or license nuclear reactors in the U. S., it is expected that CFD will be used in the design and safety analysis of forthcoming designs. This is partly because of the maturity of CFD and partly because detailed information is desired of the flow and heat transfer inside the reactor to avoid hot spots and other conditions that might compromise reactor safety. Numerical computations of turbulent flow should be validated against experimental data for flow conditions that contain some or all of the physics expected in the thermal fluid machinery of interest. To this end, a scaled model of a narrow slice of the lower plenum of the prismatic VHTR was constructed and installed in the Idaho National Laboratory’s (INL) matched index of refraction (MIR) test facility and data were taken. The data were then studied and compared to CFD calculations to help determine their suitability for validation data. One of the main findings was that the inlet data, which were measured and controlled by calibrated mass flow rotameters and were also measured using detailed stereo particle image velocimetry (PIV) showed considerable discrepancies in mass flow rate between the two methods. The other finding was that a randomly unstable recirculation zone occurs in the flow. This instability has a very significant effect on the flow field in the vicinity of the inlet jets. Because its time scale is long and because it is apparently a random instability, it was deemed undesirable for a validation data set. It was predicted using CFD that by eliminating the first of the four jets, the recirculation zone could be stabilized. The present paper reports detailed results for the three-jet case with comparisons to the four-jet data inasmuch as three-jet data are still unavailable. Hence, the present simulations are true or blind predictions.

Richard W. Johnson; Hugh M. McIlroy

2010-08-01T23:59:59.000Z

143

Simulation of hydrogen and hydrogen-assisted propane ignition in Pt catalyzed microchannel  

Science Conference Proceedings (OSTI)

This paper deals with self-ignition of catalytic microburners from ambient cold-start conditions. First, reaction kinetics for hydrogen combustion is validated with experimental results from the literature, followed by validation of a simplified pseudo-2D microburner model. The model is then used to study the self-ignition behavior of lean hydrogen/air mixtures in a Platinum-catalyzed microburner. Hydrogen combustion on Pt is a very fast reaction. During cold start ignition, hydrogen conversion reaches 100% within the first few seconds and the reactor dynamics are governed by the ''thermal inertia'' of the microburner wall structure. The self-ignition property of hydrogen can be used to provide the energy required for propane ignition. Two different modes of hydrogen-assisted propane ignition are considered: co-feed mode, where the microburner inlet consists of premixed hydrogen/propane/air mixtures; and sequential feed mode, where the inlet feed is switched from hydrogen/air to propane/air mixtures after the microburner reaches propane ignition temperature. We show that hydrogen-assisted ignition is equivalent to selectively preheating the inlet section of the microburner. The time to reach steady state is lower at higher equivalence ratio, lower wall thermal conductivity, and higher inlet velocity for both the ignition modes. The ignition times and propane emissions are compared. Although the sequential feed mode requires slightly higher amount of hydrogen, the propane emissions are at least an order of magnitude lower than the other ignition modes. (author)

Seshadri, Vikram; Kaisare, Niket S. [Department of Chemical Engineering, Indian Institute of Technology - Madras, Chennai 600 036 (India)

2010-11-15T23:59:59.000Z

144

Scalable DNS code for high Reynolds number channel flow simulation on BG/Q  

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

Scalable Scalable DNS code for high Reynolds number channel flow simulation on BG/Q MyoungKyu Lee mk@ices.utexas.edu Department of Mechanical Engineering University of Texas at Austin MiraCon Mar, 2013 M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 1 / 35 Contents Project Overview Performance Optimization Early Result Conclusion M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 2 / 35 Project Overview Project Title â—® Petascale Direct Numerical Simulations of Turbulent Channel Flow Goal â—® Expand our understand of wall-bounded turbulence Personnel â—® P.I. : Robert Moser â—® Primary Developer : M.K.Lee â—® Software Engineering Support : Nicholas Malaya â—® Catalyst : Ramesh Balakrishnan M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 3 / 35 Overlap Region Connection between near-wall

145

Particle-in-Cell Simulations of Relativistic Shear Flow Boundary Layer  

E-Print Network (OSTI)

Using 2.5-dimensional Particle-in-Cell simulations, we studied the kinetic physics of relativistic shear flows. We find efficient magnetic field generation and nonthermal particle acceleration at the shear boundary. Ordered flux tubes/sheets with alternating polarities and peak fields reaching equipartition values are generated and sustained by the free-energy of the shear flow. Nonthermal high-energy particles are accelerated by diffusive acceleration. A quasi-power-law tail truncated at low energies is achieved at strong shears. These results have important implications for the dissipation and radiation of relativistic jets.

Liang, Edison; Boettcher, Markus

2011-01-01T23:59:59.000Z

146

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

Science Conference Proceedings (OSTI)

The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.

Moridis, G.J.; Pruess (editor), K.

1992-11-01T23:59:59.000Z

147

Liquid-gas-solid flows with lattice Boltzmann: Simulation of floating bodies  

E-Print Network (OSTI)

This paper presents a model for the simulation of liquid-gas-solid flows by means of the lattice Boltzmann method. The approach is built upon previous works for the simulation of liquid-solid particle suspensions on the one hand, and on a liquid-gas free surface model on the other. We show how the two approaches can be unified by a novel set of dynamic cell conversion rules. For evaluation, we concentrate on the rotational stability of non-spherical rigid bodies floating on a plane water surface - a classical hydrostatic problem known from naval architecture. We show the consistency of our method in this kind of flows and obtain convergence towards the ideal solution for the measured heeling stability of a floating box.

Bogner, Simon

2012-01-01T23:59:59.000Z

148

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part I: Methodology, Verification, and Sensitivity Experiments  

Science Conference Proceedings (OSTI)

This paper investigates the steps necessary to achieve accurate simulations of flow over steep, mountainous terrain. Large-eddy simulations of flow in the Riviera Valley in the southern Swiss Alps are performed at horizontal resolutions as fine ...

Fotini Katopodes Chow; Andreas P. Weigel; Robert L. Street; Mathias W. Rotach; Ming Xue

2006-01-01T23:59:59.000Z

149

Simulation-assisted evaluation of potential energy savings: Application to an administrative building in France  

E-Print Network (OSTI)

The case study presented here falls within a project of feasibility studies to improve the energy efficiency, the carbon footprint and the environmental impacts of several administrative buildings in France. The first part of the paper briefly presents the data obtained during a classical audit and inspection procedure: the description of the building in term of design, the HVAC system characteristics, the occupancy and operating profiles and the control strategy applied. The second part of the paper gives the first results obtained using an evidence-based calibrated building energy simulation model to analyze the actual building global consumption but also analyze the local consumptions (heat pumps, air handling units, terminal units, lightings, pumps,...). The last part of the paper then demonstrates the possibilities given by the building energy simulation model to evaluate potential energy saving scenarios through different examples. The advantages and drawbacks of the applied methods and tools are also discussed.

Randaxhe, F.; Bertagnolio, S.; Lemort, V.

2012-01-01T23:59:59.000Z

150

Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique  

Science Conference Proceedings (OSTI)

Fluid particulate flows are common phenomena in nature and industry. Modeling of such flows at micro and macro levels as well establishing relationships between these approaches are needed to understand properties of the particulate matter. We propose a computational technique based on the direct numerical simulation of the particulate flows. The numerical method is based on the distributed Lagrange multiplier technique following the ideas of Glowinski et al. (1999). Each particle is explicitly resolved on an Eulerian grid as a separate domain, using solid volume fractions. The fluid equations are solved through the entire computational domain, however, Lagrange multiplier constrains are applied inside the particle domain such that the fluid within any volume associated with a solid particle moves as an incompressible rigid body. Mutual forces for the fluid-particle interactions are internal to the system. Particles interact with the fluid via fluid dynamic equations, resulting in implicit fluid-rigid-body coupling relations that produce realistic fluid flow around the particles (i.e., no-slip boundary conditions). The particle-particle interactions are implemented using explicit force-displacement interactions for frictional inelastic particles similar to the DEM method of Cundall et al. (1979) with some modifications using a volume of an overlapping region as an input to the contact forces. The method is flexible enough to handle arbitrary particle shapes and size distributions. A parallel implementation of the method is based on the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) library, which allows handling of large amounts of rigid particles and enables local grid refinement. Accuracy and convergence of the presented method has been tested against known solutions for a falling sphere as well as by examining fluid flows through stationary particle beds (periodic and cubic packing). To evaluate code performance and validate particle contact physics algorithm, we performed simulations of a representative experiment conducted at the University of California at Berkley for pebble flow through a narrow opening.

Kanarska, Y

2010-03-24T23:59:59.000Z

151

Simulation of water flow and retention in earthen-cover materials overlying uranium mill tailings  

SciTech Connect

The water retention characteristics of a multilayer earthen cover for uranium mill tailings were simulated under arid weather conditions common to Grand Junction, Colorado. The multilayer system described in this report consists of a layer of wet clay/gravel (radon barrier), which is separated from a surface covering of fill soil by a washed rock material used as a capillary barrier. The capillary barrier is designed to prevent the upward migration of water and salt from the tailings to the soil surface and subsequent loss of water from the wet clay. The flow model, UNSATV, described in this report uses hydraulic properties of the layered materials and historical climatic data for two years (1976 and 1979) to simulate long-term hydrologic response of the multilayer system. Application of this model to simulate the processes of infiltration, evaporation and drainage is described in detail. Simulations over a trial period of one relatively wet and two dry years indicated that the clay-gravel layer remained near saturation, and hence, that the layer was an effective radon barrier. Estimates show that the clay-gravel layer would not dry out (i.e., revert to drying dominated by isothermal vapor-flow conditions) for at least 20 years, provided that the modeled dry-climate period continues.

Simmons, C.S.; Gee, G.W.

1981-09-01T23:59:59.000Z

152

Performance characteristics of open-flow liquid desiccant solar collector/regenerator for solar cooling applications. Part 2. System simulation and performance measurements. Final report  

DOE Green Energy (OSTI)

This research focussed on the performance and system simulation of an open-flow liquid desiccant solar collector/regenerator.

Wood, B.D.; Siebe, D.A.; Applebaum, M.A.; Novak, K.S.; Ballew, L.M.

1983-11-01T23:59:59.000Z

153

A Gas-Kinetic Scheme For The Simulation Of Compressible Turbulent Flows  

E-Print Network (OSTI)

A gas-kinetic scheme for the continuum regime is applied to the simulation of turbu- lent compressible flow, by replacing the molecular relaxation time with a turbulent relaxation time in the BGK model. The turbulence dynamics is modelled on the basis of a standard, linear two-equation turbulence model. The hydrodynamic limit of the resulting turbulence model is linear in smooth flow and non-linear in the presence of stronger flow gradients. The non-linear correction terms in the numerical flux are weighed as a function of "rarefaction" - referred to turbulence dynamics and not to molecular dynamics, i.e. measured by the ratio of turbulence to mean flow scales of motion. Even though no assumptions on the nature of the turbulence have been made and a linear two-equation turbulence model is used, the turbulence gas-kinetic scheme seems able to correct the turbulent stress tensor in an effective way; on the basis of a number of turbulence modelling benchmark flow cases, characterized by strong shock - boundary l...

Righi, Marcello

2013-01-01T23:59:59.000Z

154

A Large-Eddy Simulation Study of Thermal Effects on Turbulent Flow and Dispersion in and above a Street Canyon  

Science Conference Proceedings (OSTI)

Thermal effects on turbulent flow and dispersion in and above an idealized street canyon with a street aspect ratio of 1 are numerically investigated using the parallelized large-eddy simulation model (“PALM”). Each of upwind building wall, street ...

Seung-Bu Park; Jong-Jin Baik; Siegfried Raasch; Marcus Oliver Letzel

2012-05-01T23:59:59.000Z

155

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

156

Impact of Surface Flux Formulations and Geostrophic Forcing on Large-Eddy Simulations of Diurnal Atmospheric Boundary Layer Flow  

Science Conference Proceedings (OSTI)

The impact of surface flux boundary conditions and geostrophic forcing on multiday evolution of flow in the atmospheric boundary layer (ABL) was assessed using large-eddy simulations (LES). The LES investigations included several combinations of ...

Vijayant Kumar; Gunilla Svensson; A. A. M. Holtslag; Charles Meneveau; Marc B. Parlange

2010-07-01T23:59:59.000Z

157

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

158

Transition and Equilibration of Neutral Atmospheric Boundary Layer Flow in One-Way Nested Large-Eddy Simulations Using the Weather Research and Forecasting Model  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting Model permits finescale large-eddy simulations (LES) to be nested within coarser simulations, an approach that can generate more accurate turbulence statistics and improve other aspects of simulated flows. ...

Jeff Mirocha; Gokhan Kirkil; Elie Bou-Zeid; Fotini Katopodes Chow; Branko Kosovi?

2013-03-01T23:59:59.000Z

159

Large-eddy simulations of turbulent flow for grid-to-rod fretting in nuclear reactors  

E-Print Network (OSTI)

The grid-to-rod fretting (GTRF) problem in pressurized water reactors is a flow-induced vibration problem that results in wear and failure of the fuel rods in nuclear assemblies. In order to understand the fluid dynamics of GTRF and to build an archival database of turbulence statistics for various configurations, implicit large-eddy simulations of time-dependent single-phase turbulent flow have been performed in 3x3 and 5x5 rod bundles with a single grid spacer. To assess the computational mesh and resolution requirements, a method for quantitative assessment of unstructured meshes with no-slip walls is described. The calculations have been carried out using Hydra-TH, a thermal-hydraulics code developed at Los Alamos for the Consortium for Advanced Simulation of Light water reactors, a United States Department of Energy Innovation Hub. Hydra-TH uses a second-order implicit incremental projection method to solve the single-phase incompressible Navier-Stokes equations. The simulations explicitly resolve the la...

Bakosi, J; Lowrie, R B; Pritchett-Sheats, L A; Nourgaliev, R R

2013-01-01T23:59:59.000Z

160

DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY  

SciTech Connect

The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.

Moses Bogere

2011-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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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161

COARSE-GRID SIMULATION OF REACTING AND NON-REACTING GAS-PARTICLE FLOWS  

SciTech Connect

Many processes involved in coal utilization involve handling of fine particles, their pneumatic transport, and their reactions in fluidized beds, spouted beds and circulating fluidized beds. One of the factors limiting our ability to simulate these processes is the hydrodynamics encountered in them. Two major issues that contribute to this limitation are lack of good and computationally expedient models for frictional interaction between particles, and models to capture the consequences of mesoscale structures that are ubiquitous in gas-solid flows. This project has focused on the development of these models through a combination of computer simulations and experiments. The principal goal of this project, funded under the ''DOE Vision 21 Virtual Demonstration Initiative'' is better simulation of circulating fluidized bed performance. The principal challenge funded through this cooperative agreement is to devise sound physical models for the rheological characteristics of the gas-particle mixtures and implement them in the open-domain CFD code MFIX. During the course of this project, we have made the following specific advances. (a) We have demonstrated unequivocally that sub-grid models are essential to capture, even qualitatively correctly, the macroscale flow structures in gas-particle flows in vertical risers. To this end, we developed sub-grid models of different levels of detail and exposed the sensitivity of the results obtained in coarse-grid simulations of gas-particle flow in a riser to the level of sophistication of the sub-grid models. (b) We have demonstrated that sub-grid model for the fluid-particle drag force is the most important additional feature and that the corrections for the granular phase viscosity and pressure are of secondary importance. We have also established that sub-grid models for dispersion of heat and mass are of secondary importance only. (c) We have brought forth the general character of the sub-grid model for the drag force. (d) We have performed for the first time in the literature a detailed analysis of the impact of unipolar electrostatic charges on gas-particle flow characteristics in a riser. (e) We have examined in detail the effect of wall friction and particle-particle contact (frictional) stresses on fluidization and defluidization behavior of particle assemblies, and brought forth their importance for stable operation of standpipes in a circulating fluidized bed circuit. (f) We have demonstrated that the general characteristics of contact stresses in particle assemblies and wall friction are similar for many different particles, establishing that a simple model framework can be widely applicable. (g) We have developed constitutive models for frictional regime, implemented them in MFIX and demonstrated the capability of simulating dense gas-solid flows in the frictional regime. (h) We have also performed detailed experiments to expose the nature of the stick-slip flows in silos, as a simple model system for under-aerated standpipes. All theoretical advances made in the study are implemented in MFIX and are available for public use.

Sankaran Sundaresan

2004-10-01T23:59:59.000Z

162

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

163

Implementation of variably saturated flow into PHREEQC for the simulation of biogeochemical reactions in the vadose zone  

Science Conference Proceedings (OSTI)

A software tool for the simulation of one-dimensional unsaturated flow and solute transport together with biogeochemical reactions in the vadose zone was developed by integrating a numerical solution of Richards' equation into the geochemical modelling ... Keywords: Cation exchange, Geochemical modelling, Hydraulic properties, Reactive transport, Surface complexation, Unsaturated flow

L. Wissmeier; D. A. Barry

2010-04-01T23:59:59.000Z

164

A second-order accurate immersed boundary method for fully resolved simulations of particle-laden flows  

Science Conference Proceedings (OSTI)

An immersed boundary method (IBM) with second-order spatial accuracy is presented for fully resolved simulations of incompressible viscous flows laden with rigid particles. The method is based on the computationally efficient direct-forcing method of ... Keywords: Finite-volume method, Grid locking, Immersed boundary method, Multidirect forcing scheme, Order of grid convergence, Particle-laden flow, Retraction distance

Wim-Paul Breugem

2012-05-01T23:59:59.000Z

165

A low numerical dissipation patch-based adaptive mesh refinement method for large-eddy simulation of compressible flows  

Science Conference Proceedings (OSTI)

We present a methodology for the large-eddy simulation of compressible flows with a low-numerical dissipation scheme and structured adaptive mesh refinement (SAMR). A description of a conservative, flux-based hybrid numerical method that uses both centered ... Keywords: Compressible flow, LES, Numerical methods, SAMR, Turbulence

C. Pantano; R. Deiterding; D. J. Hill; D. I. Pullin

2007-01-01T23:59:59.000Z

166

Application of automatic differentiation for the simulation of nonisothermal, multiphase flow in geothermal reservoirs  

DOE Green Energy (OSTI)

Simulation of nonisothermal, multiphase flow through fractured geothermal reservoirs involves the solution of a system of strongly nonlinear algebraic equations. The Newton-Raphson method used to solve such a nonlinear system of equations requires the evaluation of a Jacobian matrix. In this paper we discuss automatic differentiation (AD) as a method for analytically computing the Jacobian matrix of derivatives. Robustness and efficiency of the AD-generated derivative codes are compared with a conventional derivative computation approach based on first-order finite differences.

Kim, Jong G.; Finsterle, Stefan

2002-01-08T23:59:59.000Z

167

Prediction of effects of hydraulic fracturing using reservoir and well flow simulation  

Science Conference Proceedings (OSTI)

This paper presents a method to predict and evaluate effects of hydraulic fracturing jobs by using reservoir and well flow numerical simulation. The concept of the method i5 that steam production rate at the operating well head pressure is predicted with different fracture conditions which would be attained by the hydraulic fracturing jobs. Then, the effects of the hydraulic fracturing is evaluated by comparing the predicted steam production rate and that before the hydraulic fracturing. This course of analysis will suggest how large fracture should be created by the fracturing job to attain large enough increase in steam production at the operating condition and the best scheme of the hydraulic fracturing job.

Mineyuki Hanano; Tayuki Kondo

1992-01-01T23:59:59.000Z

168

Long-Term Simulations of Thermally Driven Flows and Orographic Convection at Convection-Parameterizing and Cloud-Resolving Resolutions  

Science Conference Proceedings (OSTI)

The purpose of this paper is to validate the representation of topographic flows and moist convection over the European Alps in a convection-parameterizing simulation (CPM; ?x = 6.6 km) and two cloud-resolving simulations (CRM; ?x = 1.1 and 2.2 km)...

Wolfgang Langhans; Juerg Schmidli; Oliver Fuhrer; Susanne Bieri; Christoph Schär

2013-06-01T23:59:59.000Z

169

Massively parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada  

E-Print Network (OSTI)

flows of multiphase, multicomponents in porous and fracturedmultiphase flow and multicomponent transport in porous and

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.

2001-01-01T23:59:59.000Z

170

Energy Simulation of Integrated Multiple-Zone Variable Refrigerant Flow System  

Science Conference Proceedings (OSTI)

We developed a detailed steady-state system model, to simulate the performance of an integrated five-zone variable refrigerant flow (VRF)heat pump system. The system is multi-functional, capable of space cooling, space heating, combined space cooling and water heating, and dedicated water heating. Methods were developed to map the VRF performance in each mode, based on the abundant data produced by the equipment system model. The performance maps were used in TRNSYS annual energy simulations. Using TRNSYS, we have successfully setup and run cases for a multiple-split, VRF heat pump and dehumidifier combination in 5-zone houses in 5 climates that control indoor dry-bulb temperature and relative humidity. We compared the calculated energy consumptions for the VRF heat pump against that of a baseline central air source heat pump, coupled with electric water heating and the standalone dehumidifiers. In addition, we investigated multiple control scenarios for the VRF heat pump, i.e. on/off control, variable indoor air flow rate, and using different zone temperature setting schedules, etc. The energy savings for the multiple scenarios were assessed.

Shen, Bo [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

2013-01-01T23:59:59.000Z

171

CFD Simulation of 3D Flow field in a Gas Centrifuge  

SciTech Connect

A CFD method was used to study the whole flow field in a gas centrifuge. In this paper, the VSM (Vector Splitting Method) of the FVM (Finite Volume Method) was used to solve the 3D Navier-Stokes equations. An implicit second-order upwind scheme was adopted. The numerical simulation was successfully performed on a parallel cluster computer and a convergence result was obtained. The simulation shows that: in the withdrawal chamber, a strong detached shock wave is formed in front of the scoop; as the radial position increases, the shock becomes stronger and the distance to scoop front surface is smaller. An oblique shock forms in the clearance between the scoop and the centrifuge wall; behind the shock-wave, the radially-inward motion of gas is induced because of the imbalance of the pressure gradient and the centrifugal force. In the separation chamber, a countercurrent is introduced. This indicates that CFD method can be used to study the complex three-dimensional flow field of gas centrifuges. (authors)

Dongjun Jiang; Shi Zeng [Tsinghua University, Beijing, 100084 (China)

2006-07-01T23:59:59.000Z

172

Numerical simulations of turbulent flow fields caused by spraying of water on large releases of hydrogen fluoride  

Science Conference Proceedings (OSTI)

The effectiveness of water sprays in absorbing HF releases was recently demonstrated in extended laboratory and field tests. In this paper, computer simulations are presented of the Hawk, Nevada Test Site, series of field tests. The model used, HFSPRAY, is a Eulerean/Lagrangian model which simulates the momentum, mass and energy interactions between a water spray and a turbulent plume of HF in air; the model can predict the flow velocities, temperature, water vapor, and HF concentration fields in two-dimensional large- geometries for spraying in any direction, (i.e., down-flow, inclined-down-flow, up-flow, and co-current horizontal flow). The model was validated against recent data on spraying of water on large releases of HF. 17 refs., 11 figs., 4 tabs.

Fthenakis, V.M. (Brookhaven National Lab., Upton, NY (United States)); Schatz, K.W. (Mobil Research and Development Corp., Princeton, NJ (United States))

1991-05-01T23:59:59.000Z

173

Three dimensional hysdrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic flow through porous media  

E-Print Network (OSTI)

We report the results of a study of multiphase flow in porous media. A Darcy's law for steady multiphase flow was investigated for both binary and ternary amphiphilic flow. Linear flux-forcing relationships satisfying Onsager reciprocity were shown to be a good approximation of the simulation data. The dependence of the relative permeability coefficients on water saturation was investigated and showed good qualitative agreement with experimental data. Non-steady state invasion flows were investigated, with particular interest in the asymptotic residual oil saturation. The addition of surfactant to the invasive fluid was shown to significantly reduce the residual oil saturation.

Peter J. Love; Jean-Bernard Maillet; Peter V. Coveney

2001-09-25T23:59:59.000Z

174

TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow  

DOE Green Energy (OSTI)

TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.

Pruess, K.

1991-05-01T23:59:59.000Z

175

Effects of mesh density and flow conditioning in simulating 7-pin wire wrapped fuel pins.  

Science Conference Proceedings (OSTI)

In response to the goals outlined by the U.S. Department of Energy's Global Nuclear Energy Partnership program, Argonne National Laboratory has initiated an effort to create an integrated multi-physics multi-resolution thermal hydraulic simulation tool package for the evaluation of nuclear power plant design and safety. As part of this effort, the applicability of a variety of thermal hydraulic analysis methods for the prediction of heat transfer and fluid dynamics in the wire-wrapped fuel-rod bundles found in a fast reactor core is being evaluated. The work described herein provides an initial assessment of the capabilities of the general purpose commercial computational fluid dynamics code Star-CD for the prediction of fluid dynamic characteristics in a wire wrapped fast reactor fuel assembly. A 7-pin wire wrapped fuel rod assembly based on the dimensions of fuel elements in the concept Advanced Burner Test Reactor [1] was simulated for different mesh densities and domain configurations. A model considering a single axial span of the wire wrapped fuel assembly was initially used to assess mesh resolution effects. The influence of the inflow/outflow boundary conditions on the predicted flow fields in the single-span model were then investigated through comparisons with the central span region of models which included 3 and 5 spans. The change in grid refinement had minimal impact on the inter-channel exchange within the assembly resulting in roughly a 5 percent maximum difference. The central span of the 3-span and 5-span cases exhibits much higher velocities than the single span case,, with the largest deviation (15 to 20 percent) occurring furthest away from the wire spacer grids in the higher velocity regions. However, the differences between predicted flow fields in the 3-span and 5-span models are minimal.

Smith, J. G.; Babin, B. R.; Pointer, W. D.; Fischer, P. F. (Mathematics and Computer Science); ( NE); (Kansas State Univ.)

2008-01-01T23:59:59.000Z

176

Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report  

SciTech Connect

The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNS databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is outlined as follows. Section 2 shows an assessment of numerical algorithms that are best suited for the numerical simulation of compressible flows involving turbulence and shock phenomena. Sections 3 and 4 deal with the canonical shock-turbulence interaction problem, from the DNS and LES perspectives, respectively. Section 5 considers the shock-turbulence inter-action in spherical geometry, in particular, the interaction of a converging shock with isotropic turbulence as well as the problem of the blast wave. Section 6 describes the study of shock-accelerated mixing through planar and spherical Richtmyer-Meshkov mixing as well as the shock-curtain interaction problem In section 7 we acknowledge the different interactions between Stanford and other institutions participating in this SciDAC project, as well as several external collaborations made possible through it. Section 8 presents a list of publications and presentations that have been generated during the course of this SciDAC project. Finally, section 9 concludes this report with the list of personnel at Stanford University funded by this SciDAC project.

Sanjiva Lele

2012-10-01T23:59:59.000Z

177

The impact of climate, CO2, nitrogen deposition and land use change on simulated contemporary global river flow  

SciTech Connect

We investigated how climate, rising atmospheric CO2 concentration, increasing anthropogenic nitrogen deposition and land use change influenced continental river flow over the period 1948-2004 using the Community Land Model version 4 (CLM4) with coupled river transfer model (RTM), a global river routing scheme. The model results indicate that the global mean river flow shows significant decreasing trend and climate forcing likely functions as the dominant controller of the downward trend during the study period. Nitrogen deposition and land use change account for about 5% and 2.5% of the decrease in simulated global scale river flow, respectively, while atmospheric CO2 accounts for an upward trend. However, the relative role of each driving factor is heterogeneous across regions in our simulations. The trend in river flow for the Amazon River basin is primarily explained by CO2, while land use change accounts for 27.4% of the downward trend in river flow for the Yangtze rive basin. Our simulations suggest that to better understand the trends of river flow, it is not only necessary to take into account the climate, but also to consider atmospheric composition, carbon-nitrogen interaction and land use change, particularly for regional scales.

Shi, Xiaoying [ORNL; Mao, Jiafu [ORNL; Thornton, Peter E [ORNL; Hoffman, Forrest M [ORNL; Post, Wilfred M [ORNL

2011-01-01T23:59:59.000Z

178

High-Resolution Simulations of Gas-Solids Jet Penetration Into a High Density Riser Flow  

SciTech Connect

High-resolution simulations of a gas-solids jet in a 0.3 m diameter and 15.9 m tall circulating fluidized bed (CFB) riser were conducted with the open source software-MFIX. In the numerical simulations, both gas and solids injected through a 1.6 cm diameter radial-directed tube 4.3 m above the bottom distributor were tracked as tracers, which enable the analysis of the characteristics of a two-phase jet. Two jetting gas velocities of 16.6 and 37.2 m/s were studied with the other operating conditions fixed. Reasonable flow hydrodynamics with respect to overall pressure drop, voidage, and solids velocity distributions were predicted. Due to the different dynamic responses of gas and particles to the crossflow, a significant separation of gas and solids within the jet region was predicted for both cases. In addition, the jet characteristics based on tracer concentration and tracer mass fraction profiles at different downstream levels are discussed. Overall, the numerical predictions compare favorably to the experimental measurements made at NETL.

Li, Tingwen

2011-05-01T23:59:59.000Z

179

General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes  

Science Conference Proceedings (OSTI)

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H to cylindrical radius R ratio of |H/R| {approx} 0.2-1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally-dominated ({phi}-directed) and poloidally-dominated (R-z directed) magnetic fields. Firstly, for toroidal field models and BHs with high enough |a/M|, coherent large-scale (i.e. >> H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Secondly, for poloidal field models, poloidal magnetic flux readily accretes through the disk from large radii and builds-up to a natural saturation point near the BH. While models with |H/R| {approx} 1 and |a/M| {le} 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non-axisymmetric 'magnetically choked accretion flow' (MCAF) within which the standard linear magneto-rotational instability is suppressed. The condition of a highly-magnetized state over most of the horizon is optimal for the Blandford-Znajek mechanism that generates persistent relativistic jets with and 100% efficiency for |a/M| {approx}> 0.9. A magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface forms between the compressed inflow and bulging jet magnetosphere, which drives a new jet-disk oscillation (JDO) type of quasi-periodic oscillation (QPO) mechanism. The high-frequency QPO has spherical harmonic |m| = 1 mode period of {tau} {approx} 70GM/c{sup 3} for a/M {approx} 0.9 with coherence quality factors Q {approx}> 10. Overall, our models are qualitatively distinct from most prior MHD simulations (typically, |H/R| << 1 and poloidal flux is limited by initial conditions), so they should prove useful for testing accretion-jet theories and measuring a/M in systems such as SgrA* and M87.

McKinney, Jonathan C.; Tchekhovskoy, Alexander; Blandford, Roger D.

2012-04-26T23:59:59.000Z

180

Simulating atmosphere flow for wind energy applications with WRF-LES  

SciTech Connect

Forecasts of available wind energy resources at high spatial resolution enable users to site wind turbines in optimal locations, to forecast available resources for integration into power grids, to schedule maintenance on wind energy facilities, and to define design criteria for next-generation turbines. This array of research needs implies that an appropriate forecasting tool must be able to account for mesoscale processes like frontal passages, surface-atmosphere interactions inducing local-scale circulations, and the microscale effects of atmospheric stability such as breaking Kelvin-Helmholtz billows. This range of scales and processes demands a mesoscale model with large-eddy simulation (LES) capabilities which can also account for varying atmospheric stability. Numerical weather prediction models, such as the Weather and Research Forecasting model (WRF), excel at predicting synoptic and mesoscale phenomena. With grid spacings of less than 1 km (as is often required for wind energy applications), however, the limits of WRF's subfilter scale (SFS) turbulence parameterizations are exposed, and fundamental problems arise, associated with modeling the scales of motion between those which LES can represent and those for which large-scale PBL parameterizations apply. To address these issues, we have implemented significant modifications to the ARW core of the Weather Research and Forecasting model, including the Nonlinear Backscatter model with Anisotropy (NBA) SFS model following Kosovic (1997) and an explicit filtering and reconstruction technique to compute the Resolvable Subfilter-Scale (RSFS) stresses (following Chow et al, 2005).We are also modifying WRF's terrain-following coordinate system by implementing an immersed boundary method (IBM) approach to account for the effects of complex terrain. Companion papers presenting idealized simulations with NBA-RSFS-WRF (Mirocha et al.) and IBM-WRF (K. A. Lundquist et al.) are also presented. Observations of flow through the Altamont Pass (Northern California) wind farm are available for validation of the WRF modeling tool for wind energy applications. In this presentation, we use these data to evaluate simulations using the NBA-RSFS-WRF tool in multiple configurations. We vary nesting capabilities, multiple levels of RSFS reconstruction, SFS turbulence models (the new NBA turbulence model versus existing WRF SFS turbulence models) to illustrate the capabilities of the modeling tool and to prioritize recommendations for operational uses. Nested simulations which capture both significant mesoscale processes as well as local-scale stable boundary layer effects are required to effectively predict available wind resources at turbine height.

Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B; Lundquist, K A

2008-01-14T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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.


181

Large-eddy simulations of air flow and turbulence within and around low aspect ratio cylindrical open-top chambers  

Science Conference Proceedings (OSTI)

The flow around cylindrical open-top chambers (OTCs) with aspect ratios (i.e., height-to-diameter ratios) much less than unity is investigated using a large-eddy simulation (LES) model. The solid structures are represented using the immersed ...

Philip Cunningham; Rodman R. Linn; Eunmo Koo; Cathy J. Wilson

182

Numerical Simulations of Upstream Blocking, Columnar Disturbances, and Bores in Stably Stratified Shear Flows over an Obstacle  

Science Conference Proceedings (OSTI)

A two-dimensional, nonhydrostatic, elastic numerical model has been used to study the generation of gravity waves for a stably stratified shear flow over an obstacle. When a low-level wind shear is included in the simulation, we find that the ...

Chaing Chen; James W. Rottman; Steven E. Koch

1994-11-01T23:59:59.000Z

183

Assessment of the IVA3 code for multifield flow simulation. Formal report  

Science Conference Proceedings (OSTI)

This report presents an assessment of the IVA3 computer code for multifield flow simulation, as applied to the premixing phase of a hypothetical steam explosion in a water-cooled power reactor. The first section of this report reviews the derivation of the basic partial differential equations of multifield modeling, with reference to standard practices in the multiphase flow literature. Basic underlying assumptions and approximations are highlighted, and comparison is made between IVA3 and other codes in current use. Although Kolev`s derivation of these equations is outside the mainstream of the multiphase literature, the basic partial differential equations are in fact nearly equivalent to those in other codes. In the second section, the assumptions and approximations required to pass from generic differential equations to a specific working form are detailed. Some modest improvements to the IVA3 model are suggested. In Section 3, the finite difference approximations to the differential equations are described. The discretization strategy is discussed with reference to numerical stability, accuracy, and the role of various physical phenomena - material convection, sonic propagation, viscous stress, and interfacial exchanges - in the choice of discrete approximations. There is also cause for concern about the approximations of time evolution in some heat transfer terms, which might be adversely affecting numerical accuracy. The fourth section documents the numerical solution method used in IVA3. An explanation for erratic behavior sometimes observed in the first outer iteration is suggested, along with possible remedies. Finally, six recommendations for future assessment and improvement of the IVA3 model and code are made.

Stewart, H.B.

1995-07-01T23:59:59.000Z

184

Efficient kinetic schemes for steady and unsteady flow simulations on unstructured meshes  

Science Conference Proceedings (OSTI)

This paper presents efficient second-order kinetic schemes on unstructured meshes for both compressible unsteady and incompressible steady flows. For compressible unsteady flows, a time-dependent gas distribution function with a discontinuous particle ... Keywords: Compressible unsteady flows, Efficient second-order kinetic schemes, Incompressible steady flows, Unstructured meshes

Guoxi Ni; Song Jiang; Kun Xu

2008-03-01T23:59:59.000Z

185

COARSE-GRID SIMULATION OF REACTING AND NON-REACTING GAS-PARTICLE FLOWS  

SciTech Connect

The principal goal of this project, funded under the ''DOE Vision 21 Virtual Demonstration Initiative'' is virtual demonstration of circulating fluidized bed performance. We had proposed a ''virtual demonstration tool'', which is based on the open-domain CFD code MFIX. The principal challenge funded through this grant is to devise and implement in this CFD code sound physical models for the rheological characteristics of the gas-particle mixtures. Within the past year, which was the third year of the project, we have made the following specific advances. (a) We have completed a study of the impact of sub-grid models of different levels of detail on the results obtained in coarse-grid simulations of gas-particle flow. (b) We have also completed a study of a model problem to understand the effect of wall friction, which was proved in our earlier work to be very important for stable operation of standpipes in a circulating fluidized bed circuit. These are described in a greater detail in this report.

Sankaran Sundaresan

2004-03-01T23:59:59.000Z

186

Fully Nonlinear Edge Gyrokinetic Simulations of Kinetic Geodesic-Acoustic Modes and Boundary Flows  

Science Conference Proceedings (OSTI)

We present edge gyrokinetic neoclassical simulations of tokamak plasmas using the fully nonlinear (full-f) continuum code TEMPEST. A nonlinear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson Equation. We demonstrate the following: (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high-q (tokamak safety factor), and are necessary to explain both the damping observed in our TEMPEST q-scans and experimental measurements of the scaling of the GAM amplitude with edge q{sub 95} in the absence of obvious evidence that there is a strong q dependence of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation, and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and flow characteristics qualitatively like those observed in experiments.

Xu, X Q; Belli, E; Bodi, K; Candy, J; Chang, C S; Cohen, B I; Cohen, R H; Colella, P; Dimits, A M; Dorr, M R; Gao, Z; Hittinger, J A; Ko, S; Krasheninnikov, S; McKee, G R; Nevins, W M; Rognlien, T D; Snyder, P B; Suh, J; Umansky, M V

2008-09-18T23:59:59.000Z

187

ESS 2012 Peer Review - Flow-Assisted Zinc Anode Batteries for Grid-Scale Electricity Storage - Sanjoy Banerjee, CUNY Energy Institute  

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

GRID-CONNECTED SYSTEM! GRID-CONNECTED SYSTEM! !"#$%&'()* !"#$%&'()* The CUNY EI is developing and testing hardware/software systems for peak shaving applications in commercial and industrial buildings 30KWH DEMONSTRATION !"#$%&'()*+&,-./01&2134/5& 6/57+340-4/3&809-+&6/5-+6&:%-0;/& 0/68:'?&@+/0;1&A+3<484/& & '()*+&B(CC&9/&(+4/;0-4/6&B(4%&D+E F )*+& (+&F"G!& G""H&=1:C/3& I&J"K&=7C859(:&@L:(/+:1& I&M"K&@+/0;1&@L:(/+:1& & =755/0:(-C(N/6&91&>09-+&@C/:40(:&O7B/0& %.PQRR340(+;"""GS8/P(+:S:75& FLOW-ASSISTED ZINC ANODE BATTERIES FOR GRID-SCALE ELECTRICITY STORAGE !

188

Step-flow anisotropy of the m-plane GaN (1100) grown under nitrogen-rich conditions by plasma-assisted molecular beam epitaxy  

Science Conference Proceedings (OSTI)

The homoepitaxial growth of m-plane (1100) GaN was investigated by plasma-assisted molecular beam epitaxy under nitrogen-rich conditions. The surface morphologies as a function of sample miscut were studied, providing evidence for a strong growth anisotropy that is a consequence of the anisotropy of Ga adatom diffusion barriers on the m-plane surface recently calculated ab initio[Lymperakis and Neugebauer, Phys. Rev. B 79, 241308(R) (2009)]. We found that substrate miscut toward [0001] implies a step flow toward while substrate miscut toward [0001] causes formation of atomic steps either perpendicular or parallel to the [0001] direction, under N-rich conditions at 730 deg C. We describe the growth conditions for achieving atomically flat m-plane GaN layers with parallel atomic steps.

Sawicka, Marta; Siekacz, Marcin; Skierbiszewski, Czeslaw [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); TopGaN Ltd., Sokolowska 29/37, PL-01-142 Warszawa (Poland); Turski, Henryk; Krysko, Marcin; DziePcielewski, Igor; Grzegory, Izabella [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); Smalc-Koziorowska, Julita [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, PL-01-142 Warszawa (Poland); TopGaN Ltd., Sokolowska 29/37, PL-01-142 Warszawa (Poland); Warsaw University of Technology, Faculty of Material Science and Engineering, Woloska 141, PL-02-507 Warszawa (Poland)

2011-06-15T23:59:59.000Z

189

Direct numerical simulations of multiphase flow with applications to basaltic volcanism and planetary evolution  

E-Print Network (OSTI)

Multiphase flows are an essential component of natural systems: They affect the explosivity of volcanic eruptions, shape the landscape of terrestrial planets, and govern subsurface flow in hydrocarbon reservoirs. Advancing ...

Suckale, Jenny

2011-01-01T23:59:59.000Z

190

A High-Resolution Numerical Simulation of the Wind Flow in the Ross Island Region, Antarctica  

Science Conference Proceedings (OSTI)

A detailed description of the characteristics of the three-dimensional wind flow for the Ross Island region of Antarctica is presented. This region of Antarctica has complex topographic features, and the wind flow is dependent on the topography ...

Mark W. Seefeldt; Gregory J. Tripoli; Charles R. Stearns

2003-02-01T23:59:59.000Z

191

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

192

Finite element lattice Boltzmann simulations of free surface flow in a concentric cylinder  

Science Conference Proceedings (OSTI)

The annular centrifugal contactor is a compact mixer/centrifuge device designed for liquid-liquid extraction operations in processes for recycling nuclear fuel. The flow in the annulus of a centrifugal contactor is similar to the Taylor vortex flow with ... Keywords: Concentric cylinder, Finite element method, Free surface flow, Lattice Boltzmann method

Kent E. Wardle; Taehun Lee

2013-01-01T23:59:59.000Z

193

Compressible Shear Flow Transition and Turbulence: Enhancement of GKM Numerical Scheme and Simulation/Analysis of Pressure Effects on Flow Stabilization  

E-Print Network (OSTI)

Despite significant advancements in the understanding of fluid flows, combustion and material technologies, hypersonic flight still presents numerous technological challenges. In hypersonic vehicles turbulence is critical in controlling heat generation in the boundary layer, mixing inside the combustor, generation of acoustic noise, and mass flow in the intake. The study of turbulence in highly compressible flows is challenging compared to incompressible due to a drastic change in the behavior of pressure and a relaxation of the incompressibility constraint. In addition fluid flow inside a flight vehicle is complicated by wall-effects, heat generation and complex boundary conditions. Homogeneous shear flow contains most of the relevant physics of boundary and mixing layers without the aforementioned complicating effects. In this work we aim to understand and characterize the role of pressure, velocity-pressure interaction, velocity-thermodynamics interaction in the late-stage transition-to-turbulence regime in a high speed shear dominated flow by studying the evolution of perturbations in in a high Mach number homogeneous shear flow. We use a modal-analysis based approach towards understanding the statistical behavior of turbulence. Individual Fourier waves constituting the initial flow field are studied in isolation and in combination to understand collective statistical behavior. We demonstrate proof of concept of novel acoustic based strategies for controlling the onset of turbulence. Towards this goal we perform direct numerical simulations (DNS) in three studies: (a) development and evaluation of gas kinetic based numerical tool for DNS of compressible turbulence, and perform detailed evaluation of the efficacy of different interpolation schemes in capturing solenoidal and dilatational quantities, (b) modal investigation in the behavior of pressure and isolation of linear, non-linear, inertial and pressure actions, and (c) modal investigation in the possible acoustic based control strategies in homogeneously sheared compressible flows. The findings help to understand the manifestation of the effects of compressibility on transition and turbulence via the velocity-pressure interactions and the action of individual waves. The present study helps towards the design of control mechanisms for compressible turbulence and the development of physically consistent pressure strain correlation models.

Kumar, Gaurav 1984-

2012-12-01T23:59:59.000Z

194

Modified simulated annealing technique based optimal power flow with FACTS devices  

Science Conference Proceedings (OSTI)

Simulated annealing is a probabilistic method for finding the global minimum of a cost function that may possess several local minima. In this paper, a Modified Simulated Annealing (MSA) technique is proposed to minimise the generation cost in Optimal ...

Subrata Majumdar; Ajoy Kumar Chakraborty; P. K. Chattopadhyay; Tulika Bhattacharjee

2012-07-01T23:59:59.000Z

195

Multi-dimensional computation of compressible reacting flows through porous media to apply to Internal Combustion Engine simulation  

Science Conference Proceedings (OSTI)

In this work, a new multi-dimensional Finite Volume (FV) solver of partial differential equations (PDEs) for compressible and reacting flows through porous media has been developed. The solver makes use of a pseudo-staggered arrangement, in order to ... Keywords: CFD, Computational fluid dynamics, DPF, Diesel exhaust after-treatment simulation, Diesel particulate filters, ICE, Internal combustion engines, Numerical methods, Porous media solver

F. Piscaglia; A. Montorfano; A. Onorati

2010-10-01T23:59:59.000Z

196

Sources of Uncertainty and Error in the Simulation of Flow in Porous Media  

E-Print Network (OSTI)

of Petroelum Engineers, 2001. SPE Reservoir Simulation Symposium held in Houston, Texas, 11-14 Feb. [7

New York at Stoney Brook, State University of

197

Simulation of the Gas Flow in a Peirce-Smith Converter  

Science Conference Proceedings (OSTI)

ChemSheet as a Simulation Platform for Pyrometallurgical Processes ... Recent Developments in FactSage Thermochemical Software and Databases.

198

A new computational paradigm in multiscale simulations: application to brain blood flow  

Science Conference Proceedings (OSTI)

Interfacing atomistic-based with continuum-based simulation codes is now required in many multiscale physical and biological systems. We present the computational advances that have enabled the first multiscale simulation on 190,740 processors by coupling ... Keywords: cerebrovascular circulation, continuum-atomistic simulations, coupled solvers, multi-scale modeling

Leopold Grinberg; Joseph A. Insley; Vitali Morozov; Michael E. Papka; George Em Karniadakis; Dmitry Fedosov; Kalyan Kumaran

2011-11-01T23:59:59.000Z

199

Computational fluid dynamics simulation of the air/suppressant flow in an uncluttered F18 engine nacelle  

DOE Green Energy (OSTI)

For the purposes of designing improved Halon-alternative fire suppression strategies for aircraft applications, Computational Fluid Dynamics (CFD) simulations of the air flow, suppressant transport, and air-suppressant mixing within an uncluttered F18 engine nacelle were performed. The release of inert gases from a Solid Propellant Gas Generator (SPGG) was analyzed at two different injection locations in order to understand the effect of injection position on the flow patterns and the mixing of air and suppression agent. An uncluttered engine nacelle was simulated to provide insight into the global flow features as well as to promote comparisons with previous nacelle fire tests and recent water tunnel tests which included little or no clutter. Oxygen concentration levels, fuel/air residence times that would exist if a small fuel leak were present, velocity contours, and streamline patterns are presented inside the engine nacelle. The numerical results show the influence of the gent release location on regions of potential flame extinction due to oxygen inerting and high flame strain. The occurrence of inflow through the exhaust ducts on the aft end of the nacelle is also predicted. As expected, the predicted oxygen concentration levels were consistently higher than the measured levels since a fire was not modeled in this analysis. Despite differences in the conditions of these simulations and the experiments, good agreement was obtained between the CFD predictions and the experimental measurements.

Lopez, A.R.; Gritzo, L.A.; Hassan, B.

1997-06-01T23:59:59.000Z

200

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-duration (life-time) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured Solar atmosphere.

Swadesh M. Mahajan; Nana L. Shatashvili; Solomon V. Mikeladze; Ketevan I. Sigua

2005-02-17T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

An unstructured finite volume simulator for multiphase flow through fractured-porous media.  

E-Print Network (OSTI)

??Modeling of multiphase flow in fractured media plays an integral role in management and performance prediction of oil and gas reserves. Geological characterization and nmultiphase… (more)

Bajaj, Reena

2009-01-01T23:59:59.000Z

202

On some problems in the simulation of flow and transport through porous media.  

E-Print Network (OSTI)

??The dynamic solution of multiphase flow through porous media is of special interest to several fields of science and engineering, such as petroleum, geology and… (more)

Thomas, Sunil George

2009-01-01T23:59:59.000Z

203

Acceleration of plasma flows in the closed magnetic fields: Simulation and analysis  

Science Conference Proceedings (OSTI)

Within the framework of a two-fluid description, possible pathways for the generation of fast flows (dynamical as well as steady) in the closed magnetic fields are established. It is shown that a primary plasma flow (locally sub-Alfvenic) is accelerated while interacting with ambient arcade-like closed field structures. The time scale for creating reasonably fast flows (> or approx. 100 km/s) is dictated by the initial ion skin depth, while the amplification of the flow depends on local plasma {beta}. It is shown that distances over which the flows become 'fast' are {approx}0.01R{sub 0} from the interaction surface (R{sub 0} being a characteristic length of the system); later, the fast flow localizes (with dimensions or approx. 500 km/s) of the accelerated flow and the modification of the field structure are independent of the time duration (lifetime) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured stellar atmospheres; their relevance to the solar wind is also obvious.

Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Plasma Physics Department, Tbilisi State University, Tbilisi 0128 and Georgia Abdus Salam International Centre for Theoretical Physics, 34014 Trieste (Italy); Andronikashvili Institute of Physics, Georgian Academy of Sciences, Tbilisi 0177 (Georgia)

2006-06-15T23:59:59.000Z

204

Simulation and modeling of flow field around a horizontal axis wind turbine (HAWT) using RANS method.  

E-Print Network (OSTI)

??The principal objective of the proposed CFD analysis is to investigate the flow field around a horizontal axis wind turbine rotor and calculate the turbine's… (more)

Sargsyan, Armen.

2010-01-01T23:59:59.000Z

205

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-d...

Mahajan, S M; Mikeladze, S V; Sigua, K I; Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I.

2005-01-01T23:59:59.000Z

206

Multi-scale finite-volume method for elliptic problems in subsurface flow simulation  

Science Conference Proceedings (OSTI)

In this paper we present a multi-scale finite-volume (MSFV) method to solve elliptic problems with many spatial scales arising from flow in porous media. The method efficiently captures the effects of small scales on a coarse grid, is conservative, and ... Keywords: finite-volume, multi-scale physics, subsurface flow, upscaling

P. Jenny; S. H. Lee; H. A. Tchelepi

2003-05-01T23:59:59.000Z

207

Simulating Field-Scale Moisture Flow Using a Combined Power-Averaging and Tensorial Connectivity-Tortuosity Approach  

SciTech Connect

Various stochastic methods have been developed over the past two decades to estimate effective unsaturated hydraulic properties. We develop in this paper an alternative practical approach to estimate three-dimensional effective unsaturated hydraulic conductivity via a combined power-averaging and tensorial connectivity-tortuosity (PA-TCT) model. An application of the new approach to data collected at a field injection site suggests that the PA-TCT model provides 1) a reasonable framework for upscaling core-scale measurements and 2) an accurate simulation of moisture flow in a heterogeneous vadose zone. The heterogeneous media at the injection site is composed of multiple geologic units, each of which is represented by an anisotropic equivalent homogeneous medium (EHM). The directional effective hydraulic conductivity for each anisotropic EHM was determined by upscaling the laboratory-measured hydraulic properties with the combined PA-TCT approach. A larger difference between the power values in the horizontal and vertical directions indicates a larger macroscopic anisotropy in unsaturated hydraulic conductivity. A moment analysis was used to quantify the center of mass and the spread of the moisture content difference. Numerical simulations showed that, if the flow domain were treated as being isotropic, the vertical migration was significantly overestimated while the lateral movement was underestimated when compared to observations. To the contrary, if the media was treated as perfectly stratified, the lateral moisture movement was considerably overestimated while the vertical movement was underestimated. However, when the flow domain was modeled as being mildly anisotropic with the PA-TCT based parameters, the model can successfully predict the moisture flow and the simulated plume matched the observed moisture plume the best.

Zhang, Z. F.; Khaleel, Raziuddin

2010-09-02T23:59:59.000Z

208

Simulation of power flow in magnetically insulated convolutes for pulsed modular accelerators  

Science Conference Proceedings (OSTI)

Two distinct simulation approaches for magnetic insulation are developed which can be used to address the question of nonsimultaneity. First, a two-dimensional model for a two-module system is simulated using a fully electromagnetic, two-dimensional, time-dependent particle code. Next, a nonlinear equivalent circuit approach is used to compare with the direct simulation for the two module case. The latter approach is then extended to a more interesting three-dimensional geometry with several MITL modules.

Seidel, D. B.; Goplen, B. C.; VanDevender, J. P.

1980-01-01T23:59:59.000Z

209

Aeroelastic instabilities simulations on turbofan HP compressorblisk at surge-like reversed flow conditions.  

E-Print Network (OSTI)

?? This paper presents the work done at the High Pressure Compressor design division of Safran Snecma to simulate the flutter behaviour of a compressor… (more)

Murray, Raphael

2013-01-01T23:59:59.000Z

210

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

211

An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation  

Science Conference Proceedings (OSTI)

The scale-dependence of geochemical reaction rates hinders their use in continuum scale models intended for the interpretation and prediction of chemical fate and transport in subsurface environments such as those considered for geologic sequestration of CO{sub 2}. Processes that take place at the pore scale, especially those involving mass transport limitations to reactive surfaces, may contribute to the discrepancy commonly observed between laboratory-determined and continuum-scale or field rates. Here, the dependence of mineral dissolution rates on the pore structure of the porous media is investigated by means of pore scale modeling of flow and multicomponent reactive transport. The pore scale model is comprised of high performance simulation tools and algorithms for incompressible flow and conservative transport combined with a general-purpose multicomponent geochemical reaction code. The model performs direct numerical simulation of reactive transport based on an operator-splitting approach to coupling transport and reactions. The approach is validated with a Poiseuille flow single-pore experiment and verified with an equivalent 1D continuum-scale model of a capillary tube packed with calcite spheres. Using the case of calcite dissolution as an example, the high resolution model is used to demonstrate that non-uniformity in the flow field at the pore scale has the effect of decreasing the overall reactivity of the system, even when systems with identical reactive surface area are considered. The effect becomes more pronounced as the heterogeneity of the reactive grain packing increases, particularly where the flow slows sufficiently such that the solution approaches equilibrium locally and the average rate becomes transport-limited.

Rafa, S. Molins; Trebotich, D.; Steefel, C. I.; Shen, C.

2012-02-01T23:59:59.000Z

212

Effect of Turbulence Models and Spatial Resolution on Resolved Velocity Structure and Momentum Fluxes in Large-Eddy Simulations of Neutral Boundary Layer Flow  

Science Conference Proceedings (OSTI)

This paper demonstrates the importance of high-quality subfilter-scale turbulence models in large-eddy simulations by evaluating the resolved-scale flow features that result from various closure models. The Advanced Regional Prediction System (...

Francis L. Ludwig; Fotini Katopodes Chow; Robert L. Street

2009-06-01T23:59:59.000Z

213

Modeling and Simulation of Pore Scale Multiphase Fluid Flow and Reactive Transport in Fractured and Porous Media  

Science Conference Proceedings (OSTI)

In the subsurface fluids play a critical role by transporting dissolved minerals, colloids and contaminants (sometimes over long distances), by mediating dissolution and precipitation processes and enabling chemical transformations in solution and at mineral surfaces. Although the complex geometries of fracture apertures, fracture networks and pore spaces may make it difficult to accurately predict fluid flow in saturated (single-phase) subsurface systems, well developed methods are available. The simulation of multiphase fluid flow in the subsurface is much more challenging because of the large density and/or viscosity ratios found in important applications (water/air in the vadose zone, water/oil, water/gas, gas/oil and water/oil/gas in oil reservoirs, water/air/non-aqueous phase liquids (NAPL) in contaminated vadose zone systems and gas/molten rock in volcanic systems, for example). In addition, the complex behavior of fluid-fluid-solid contact lines, and its impact on dynamic contact angles, must also be taken into account, and coupled with the fluid flow. Pore network models and simple statistical physics based models such as the invasion percolation and diffusion-limited aggregation models have been used quite extensively. However, these models for multiphase fluid flow are based on simplified models for pore space geometries and simplified physics. Other methods such a lattice Boltzmann and lattice gas models, molecular dynamics, Monte Carlo methods, and particle methods such as dissipative particle dynamics and smoothed particle hydrodynamics are based more firmly on first principles, and they do not require simplified pore and/or fracture geometries. However, they are less (in some cases very much less) computationally efficient that pore network and statistical physics models. Recently a combination of continuum computation fluid dynamics, fluid-fluid interface tracking or capturing and simple models for the dependence of contact angles on fluid velocity at the contact line has been used to simulate multiphase fluid flow in fracture apertures, fracture networks and pore spaces. Fundamental conservation principles - conservation of momentum, and conservation of mass (or conservation of volume for incompressible fluids) and conservation of energy, as well as symmetries (Galilean invariance and isotropy) are central to the physics of fluids and the models used to simulate them. In molecular and mesoscale models observance of these conservation principles and symmetries at the microscopic level leads to macroscopic fluid dynamics that can be represented by the Navier Stokes equation. The remarkable fact that the flow of all simpe fluids, irrespective of their chemical nature, can be described by the Navier-Stokes equation is a result of these conservation principles and symmetries acting on the molecular level.

Paul Meakin; Alexandre Tartakovsky

2009-07-01T23:59:59.000Z

214

Spectral element/smoothed profile method for turbulent flow simulations of waterjet propulsion systems  

E-Print Network (OSTI)

We have developed fast numerical algorithms [1] for flows with complex moving domains, e.g. propellers in free-space and impellers in waterjets, by combining the smoothed profile method (SPM, [2, 3, 4]) with the spectral ...

Luo, Xian

215

The Interaction of Katabatic Flow and Mountain Waves. Part I: Observations and Idealized Simulations  

Science Conference Proceedings (OSTI)

The mutual interaction of katabatic flow in the nocturnal boundary layer (NBL) and topographically forced gravity waves is investigated. Due to the nonlinear nature of these phenomena, analysis focuses on information obtained from the 1993 ...

Gregory S. Poulos; James E. Bossert; Thomas B. McKee; Roger A. Pielke

2000-06-01T23:59:59.000Z

216

Numerical Simulation of Boundary Layer Structure and Cross-Equatorial Flow in the Eastern Pacific  

Science Conference Proceedings (OSTI)

Recent observations from spaceborne microwave sensors have revealed detailed structure of the surface flow over the equatorial eastern Pacific in the boreal fall season. A marked acceleration of surface wind across the northern sea surface ...

R. Justin Small; Shang-Ping Xie; Yuqing Wang; Steven K. Esbensen; Dean Vickers

2005-06-01T23:59:59.000Z

217

Mesoscale Simulation of Supercritical, Subcritical, and Transcritical Flow along Coastal Topography  

Science Conference Proceedings (OSTI)

A mesoscale atmospheric model is used to address the characteristics of stratified flow bounded by a side wall along a varying coastline. Initial Froude number values are varied through alteration of marine inversion strength, permitting ...

Stephen D. Burk; Tracy Haack; R. M. Samelson

1999-08-01T23:59:59.000Z

218

Flow over Heated Terrain. Part I: Linear Theory and Idealized Numerical Simulations  

Science Conference Proceedings (OSTI)

The flow past heated topography is examined with both linear and nonlinear models. It is first shown that the forcing of an obstacle with horizontally homogenous surface heating can be approximated by the forcing of an obstacle with surface ...

N. Andrew Crook; Donna F. Tucker

2005-09-01T23:59:59.000Z

219

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

in Porous Media," SAND84-2057, Sandia National Laboratories,and Field Comparison of the Sandia . Waste-Isolation FlowNUREG/CR-3316, SAND83- 1154, Sandia National Laboratories,

Moridis, G.J.

2010-01-01T23:59:59.000Z

220

Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model  

Science Conference Proceedings (OSTI)

During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical ...

K. Shankar Rao; Richard M. Eckman; Rayford P. Hosker Jr.

1989-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Modeling, Analysis and Simulation of Multiscale Preferential Flow - 8/05-8/10 - Final Report  

SciTech Connect

The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

Ralph Showalter; Malgorzata Peszynska

2012-07-03T23:59:59.000Z

222

Original article: Numerical simulation of two-phase flow in deformable porous media: Application to carbon dioxide storage in the subsurface  

Science Conference Proceedings (OSTI)

In this paper, conceptual modeling as well as numerical simulation of two-phase flow in deep, deformable geological formations induced by CO"2 injection are presented. The conceptual approach is based on balance equations for mass, momentum and energy ... Keywords: Carbon capture storage (CCS), Heat transport, OpenGeoSys (OGS), Porous media, Two-phase flow consolidation

O. Kolditz; S. Bauer; N. BöTtcher; D. Elsworth; U. -J. GöRke; C. -I. Mcdermott; C. -H. Park; A. K. Singh; J. Taron; W. Wang

2012-06-01T23:59:59.000Z

223

Two-Phase Flow Simulations In a Natural Rock Fracture using the VOF Method  

Science Conference Proceedings (OSTI)

Standard models of two-phase flow in porous media have been shown to exhibit several shortcomings that might be partially overcome with a recently developed model based on thermodynamic principles (Hassanizadeh and Gray, 1990). This alternative two-phase flow model contains a set of new and non-standard parameters, including specific interfacial area. By incorporating interfacial area production, destruction, and propagation into functional relationships that describe the capillary pressure and saturation, a more physical model has been developed. Niessner and Hassanizadeh (2008) have examined this model numerically and have shown that the model captures saturation hysteresis with drainage/imbibition cycles. Several static experimental studies have been performed to examine the validity of this new thermodynamically based approach; these allow the determination of static parameters of the model. To date, no experimental studies have obtained information about the dynamic parameters required for the model. A new experimental porous flow cell has been constructed using stereolithography to study two-phase flow phenomena (Crandall et al. 2008). A novel image analysis tool was developed for an examination of the evolution of flow patterns during displacement experiments (Crandall et al. 2009). This analysis tool enables the direct quantification of interfacial area between fluids by matching known geometrical properties of the constructed flow cell with locations identified as interfaces from images of flowing fluids. Numerous images were obtained from two-phase experiments within the flow cell. The dynamic evolution of the fluid distribution and the fluid-fluid interface locations were determined by analyzing these images. In this paper, we give a brief introduction to the thermodynamically based two-phase flow model, review the properties of the stereolithography flow cell, and show how the image analysis procedure has been used to obtain dynamic parameters for the numerical model. These parameters include production/destruction of interfacial area as a function of saturation and capillary pressure. Our preliminary results for primary drainage in porous media show that the specific interfacial area increased linearly with increasing gas saturation until breakthrough of the displacing gas into the exit manifold occurred.

Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H., Bromhal, Grant

2010-01-01T23:59:59.000Z

224

Simulations for Complex Fluid Flow Problems from Berkeley Lab's Center for Computational Sciences and Engineering (CCSE)  

DOE Data Explorer (OSTI)

The Center for Computational Sciences and Engineering (CCSE) develops and applies advanced computational methodologies to solve large-scale scientific and engineering problems arising in the Department of Energy (DOE) mission areas involving energy, environmental, and industrial technology. The primary focus is in the application of structured-grid finite difference methods on adaptive grid hierarchies for compressible, incompressible, and low Mach number flows. The diverse range of scientific applications that drive the research typically involve a large range of spatial and temporal scales (e.g. turbulent reacting flows) and require the use of extremely large computing hardware, such as the 153,000-core computer, Hopper, at NERSC. The CCSE approach to these problems centers on the development and application of advanced algorithms that exploit known separations in scale; for many of the application areas this results in algorithms are several orders of magnitude more efficient than traditional simulation approaches.

225

Experiments and Simulations on Coastal Flows in the Presence of a Topographic Slope  

Science Conference Proceedings (OSTI)

The evolution of a barotropic coastal current in the presence of a bottom ramp-shaped topography is studied by means of laboratory experiments and numerical simulations. The experiments are performed in a rectangular rotating tank filled with ...

L. Zavala Sansón; R. Serravall; G. F. Carnevale; G. J. F. van Heijst

2005-11-01T23:59:59.000Z

226

Large Eddy Simulation of Turbulent Flow in a Marine Convective Boundary Layer with Snow  

Science Conference Proceedings (OSTI)

A large eddy simulation (LES) model, with ice phase included, has been used to study the marine convective boundary layer filled with snow. Extensions to Moeng's LES model include the diagnosis of cloud ice mixing ratio, snow precipitation, and ...

Guan-Shu Rao; Ernest M. Agee

1996-01-01T23:59:59.000Z

227

Investigating the Applicability of Error Correction Ensembles of Satellite Rainfall Products in River Flow Simulations  

Science Conference Proceedings (OSTI)

This study uses a stochastic ensemble-based representation of satellite rainfall error to predict the propagation in flood simulation of three quasi-global-scale satellite rainfall products across a range of basin scales. The study is conducted on ...

Viviana Maggioni; Humberto J. Vergara; Emmanouil N. Anagnostou; Jonathan J. Gourley; Yang Hong; Dimitrios Stampoulis

2013-08-01T23:59:59.000Z

228

Regional Climate Simulations over North America: Interaction of Local Processes with Improved Large-Scale Flow  

Science Conference Proceedings (OSTI)

The reasons for biases in regional climate simulations were investigated in an attempt to discern whether they arise from deficiencies in the model parameterizations or are due to dynamical problems. Using the Regional Atmospheric Modeling System ...

Gonzalo Miguez-Macho; Georgiy L. Stenchikov; Alan Robock

2005-04-01T23:59:59.000Z

229

The Conservation of Potential vorticity along Lagrangian Trajectories in Simulations of Eddy-Driven Flows  

Science Conference Proceedings (OSTI)

The purpose of this note is to investigate the use of Lagrangian potential vorticity conservation as a numerically independent method for checking a posteriori the dynamical consistency of an eddy-resolving GCM simulation. This is performed for a ...

Bach Lien Hua

1994-02-01T23:59:59.000Z

230

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

SciTech Connect

This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC{sup 3D} geomechanical simulator. The most significant new TOUGH-FLAC development in the past few years is a revised architecture, enabling a more rigorous and tight coupling procedure with improved computational efficiency. The applications presented in this paper are related to modeling of crustal deformations caused by deep underground fluid movements and pressure changes as a result of both industrial activities (the In Salah CO{sub 2} Storage Project and the Geysers Geothermal Field) and natural events (the 1960s Matsushiro Earthquake Swarm). Finally, the paper provides some perspectives on the future of TOUGH-FLAC in light of its applicability to practical problems and the need for high-performance computing capabilities for field-scale problems, such as industrial-scale CO{sub 2} storage and enhanced geothermal systems. It is concluded that despite some limitations to fully adapting a commercial code such as FLAC{sup 3D} for some specialized research and computational needs, TOUGH-FLAC is likely to remain a pragmatic simulation approach, with an increasing number of users in both academia and industry.

Rutqvist, J.

2010-06-01T23:59:59.000Z

231

A preliminary evaluation of the performance of wind tunnel and numerical modeling simulations of the wind flow over a wind farm  

SciTech Connect

This report is an analysis of physical and numerical model simulations of the wind flow over complex terrain. The specific area to which these models were applied is a wind farm in the Altamont Pass area of California. The physical model results were obtained from wind tunnel flow simulations, and the numerical model used was the optimizing version of the NOABL model. The goals of this analysis were (1) to evaluate the relative performance of the two models and (2) to uncover any clues that would point toward improvement of the wind tunnel modeling. The performances of the models were gauged by comparing model simulations to wind observations taken over the modeled area.

Barnard, J.C.; Wegley, H.L.

1987-01-01T23:59:59.000Z

232

Using Adaptive Agent-Based Simulation Models to Assist Planners in Policy: The Case of Rent Control  

E-Print Network (OSTI)

: 2 Computer simulation modeling for policy development in planning has had difficulty gaining a consistent foothold. Reasons for this include bad experiences with large-scale, comprehensive models (e.g., Forrester, 1969) and the lack of theory that one can quantify (Batty, 1994). Batty (1994) has suggested that new types of computational models, based on the tenets of complexity theory (Bernard, under revision) may prove useful. One type of complexity theory model is an "adaptive agent based model" in which the actions, interactions, and adaptations of many autonomous, heterogeneous "agents" (households, firms, etc.) produce emergent, systemwide behavior. One can examine this emergent behavior using commonly employed metrics, but one can also garner a richer, more intuitive understanding of how the individual behavior of the agents self-organize to produce the entire system. Using this type of modeling for small-scale planning problems can both inform planning theorists and improve ...

Robert N. Bernard

1999-01-01T23:59:59.000Z

233

Simulation Analysis of Within-Day Flow Fluctuation Effects on Trout below Flaming Gorge Dam  

Science Conference Proceedings (OSTI)

This report demonstrates the use of an individual-based model for studying the impact of river flow fluctuations resulting from hydroelectric project operation on a tailwater trout fishery. The study was conducted at the Flaming Gorge Hydroelectric Project on the Green River in Utah.

2006-04-20T23:59:59.000Z

234

Numerical simulation of fluid flow and heat transfer in a water heater  

Science Conference Proceedings (OSTI)

Energy consumption represents a major concern, considering the limited resources and latest targets for lower emissions of carbon dioxide. Therefore design of electric heating elements for household and industry are more and more subject to optimization, ... Keywords: electric heating, finite elements, fluid flow, heat transfer

Mircea Nicoar?; Aurel R?du??; Lauren?iu Roland Cucuruz; Cosmin Locovei

2010-04-01T23:59:59.000Z

235

Numerical Simulation of Flow Field in Diesel Centrifugal Gas-Oil Separator Basing on CFD  

Science Conference Proceedings (OSTI)

Aiming at the low efficiency problem of the traditional gas-oil separator, this paper put forward a centrifugal gas-oil separator. In order to identify out the interior fluid field character of centrifugal gas-oil separator, RANS equation, RNG k-e model ... Keywords: Diesel, Centrifugal Gas-oil Separator, Flow Field, Separation Efficiency

Zhiguo Zhao

2012-07-01T23:59:59.000Z

236

An efficient correction procedure via reconstruction for simulation of viscous flow on moving and deforming domains  

Science Conference Proceedings (OSTI)

In this paper, we report the development of a new parallel solver using the Correction Procedure via Reconstruction (CPR) for viscous flows on moving and deforming grids. By employing an accurate treatment of flux derivatives for moving and deforming ... Keywords: Correction procedure via reconstruction, Moving and deforming grids, Parallel Navier-Stokes solver, Quadrilateral element, Unstructured grid

Chunlei Liang, Koji Miyaji, Bin Zhang

2014-01-01T23:59:59.000Z

237

An accurate tangential forcedisplacement model for granular-flow simulations: Contacting spheres with  

E-Print Network (OSTI)

is consistent with the elasto-plastic normal force­displacement (NFD) model presented in [ASME Journal-Quoc). URL: http://www.mae.ufl.edu/~vql. 1 Now with Parametric Technology Corp. (PTC), Needham, MA. 2 Now of the flow, play a crucial role. It has been amply demonstrated in [6] that an accurate tangential force

Vu-Quoc, Loc

238

A screening model for simulating DNAPL flow and transport in porous media: theoretical development  

Science Conference Proceedings (OSTI)

In the last two decades there has been an increased awareness of the contamination of groundwater due to the presence of denser-than-water nonaqueous phase liquids (DNAPLs). Numerous theoretical, experimental and numerical investigations have been conducted ... Keywords: Contaminant transport, Multiphase flow, Screening model

Clinton S. Willson; James W. Weaver; Randall J. Charbeneau

2006-01-01T23:59:59.000Z

239

Towards accelerating smoothed particle hydrodynamics simulations for free-surface flows on multi-GPU clusters  

Science Conference Proceedings (OSTI)

Starting from the single graphics processing unit (GPU) version of the Smoothed Particle Hydrodynamics (SPH) code DualSPHysics, a multi-GPU SPH program is developed for free-surface flows. The approach is based on a spatial decomposition technique, whereby ... Keywords: CUDA, Computational fluid dynamics, GPU, Graphics processing unit, Molecular dynamics, Multi-GPU, SPH, Smoothed particle hydrodynamics

Daniel Valdez-Balderas, José M. Domínguez, Benedict D. Rogers, Alejandro J. C. Crespo

2013-11-01T23:59:59.000Z

240

Numerical Simulation of Flow around a Tall Isolated Seamount. Part I: Problem Formulation and Model Accuracy  

Science Conference Proceedings (OSTI)

A sigma coordinate ocean circulation model is employed to study flow trapped to a tall seamount in a periodic f-plane channel. In Part I, errors arising from the pressure gradient formulation in the steep topography/strong stratification limit ...

Aike Beckmann; Dale B. Haidvogel

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Evaluations of emitter clogging in drip irrigation by two-phase flow simulations and laboratory experiments  

Science Conference Proceedings (OSTI)

Emitter clogging will affect greatly the irrigation efficiency and the running cost of a drip irrigation system. If there is an effective method to predict the emitter clogging, the lost will be reduced to a minimum. A solid-liquid two-phase turbulent ... Keywords: Clogging, Computational fluid dynamics, Drip emitters, Drip irrigation, Two-phase flow

Wei Qingsong; Lu Gang; Liu Jie; Shi Yusheng; Dong Wenchu; Huang Shuhuai

2008-10-01T23:59:59.000Z

242

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

DOE Green Energy (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

2010-08-01T23:59:59.000Z

243

Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests  

SciTech Connect

Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative to volcanic-rock units is exemplified by the large difference in their estimated maximum hydraulic conductivity; 4,000 and 400 feet per day, respectively. Simulated minimum estimates of hydraulic conductivity are inexact and represent the lower detection limit of the method. Minimum thicknesses of lithologic intervals also were defined for comparing AnalyzeHOLE results to hydraulic properties in regional ground-water flow models.

Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

2010-02-12T23:59:59.000Z

244

Flow around a Complex Building: Experimental and Large-Eddy Simulation Comparisons  

Science Conference Proceedings (OSTI)

A field program to study atmospheric releases around a complex building was performed in the summers of 1999 and 2000. The focus of this paper is to compare field data with a large-eddy simulation (LES) code to assess the ability of the LES ...

Ronald Calhoun; Frank Gouveia; Joseph Shinn; Stevens Chan; Dave Stevens; Robert Lee; John Leone

2005-05-01T23:59:59.000Z

245

Development of Java multi-threaded simulation for chemical reacting flow of ethanol  

Science Conference Proceedings (OSTI)

Multi-threading in Java enhances computational performance and facilitates the development of parallel software. To obtain high performance on multi-core systems, this study develops a multi-threaded simulation code using Java for the chemical reacting ... Keywords: Benchmark, Chemical reaction, Computational fluid dynamics, Ethanol detonation, Java, Multi-thread

E. Yamada; T. Shimada; A. K. Hayashi

2012-12-01T23:59:59.000Z

246

A new domain decomposition method with overlapping patches for ultrascale simulations: Application to biological flows  

Science Conference Proceedings (OSTI)

We address the failure in scalability of large-scale parallel simulations that are based on (semi-)implicit time-stepping and hence on the solution of linear systems on thousands of processors. We develop a general algorithmic framework based on domain ... Keywords: Arterial network, CFD, Multi-domain decomposition, Petaflop computing, Scalability, Spectral element method

L. Grinberg; G. E. Karniadakis

2010-08-01T23:59:59.000Z

247

Multiphase flow reconstruction in oil pipelines by capacitance tomography using simulated annealing  

E-Print Network (OSTI)

simulated annealing (SA) algorithm is applied to reconstruct permittivity images of real two-phase gas- oil such as mixing or stirring vessels, fluidized bed reactors, separator tanks and pipelines carrying multiphase in a cylindrical configuration close to the electrodes in order to improve resolution in the calculation

Martin, Roland

248

Intergrated 3-D Ground-Penetrating Radar,Outcrop,and Boreholoe Data Applied to Reservoir Characterization and Flow Simulation.  

Science Conference Proceedings (OSTI)

Existing reservoir models are based on 2-D outcrop;3-D aspects are inferred from correlation between wells,and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we initiated a multidimensional characterization of reservoir analogs in the Cretaceous Ferron Sandstone in Utah.The study was conducted at two sites(Corbula Gulch Coyote Basin); results from both sites are contained in this report. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of potential reservoir flow units, barriers and baffles at the outcrop. High resolution 2-D and 3-D ground penetrating radar(GPR) images extend these reservoir characteristics into 3-D to allow development of realistic 3-D reservoir models. Models use geometric information from the mapping and the GPR data, petrophysical data from surface and cliff-face outcrops, lab analyses of outcrop and core samples, and petrography. The measurements are all integrated into a single coordinate system using GPS and laser mapping of the main sedimentologic features and boundaries. The final step is analysis of results of 3-D fluid flow modeling to demonstrate applicability of our reservoir analog studies to well siting and reservoir engineering for maximization of hydrocarbon production. The main goals of this project are achieved. These are the construction of a deterministic 3-D reservoir analog model from a variety of geophysical and geologic measurements at the field sites, integrating these into comprehensive petrophysical models, and flow simulation through these models. This unique approach represents a significant advance in characterization and use of reservoir analogs. To data,the team has presented five papers at GSA and AAPG meetings produced a technical manual, and completed 15 technical papers. The latter are the main content of this final report. In addition,the project became part of 5 PhD dissertations, 3 MS theses,and two senior undergraduate research projects.

McMechan et al.

2001-08-31T23:59:59.000Z

249

Numerical simulation of single-phase and multiphase non-Darcy flow in porous and fractured reservoirs  

E-Print Network (OSTI)

well tests, multiphase flow, porous and fracturedin modeling multiphase flow in porous and fractured media,”description of multiphase flow through porous media: S w + S

Wu, Yu-Shu

2000-01-01T23:59:59.000Z

250

Simulations of Groundwater Flow and Radionuclide Transport in the Vadose and Saturated Zones beneath Area G, Los Alamos National Laboratory  

Science Conference Proceedings (OSTI)

Numerical simulations are used to predict the migration of radionuclides from the disposal units at Material Disposal Area G through the vadose zone and into the main aquifer in support of a radiological performance assessment and composite analysis for the site. The calculations are performed with the finite element code, FEHM. The transport of nuclides through the vadose zone is computed using a three-dimensional model that describes the complex mesa top geology of the site. The model incorporates the positions and inventories of thirty-four disposal pits and four shaft fields located at Area G as well as those of proposed future pits and shafts. Only three nuclides, C-14, Tc-99, and I-129, proved to be of concern for the groundwater pathway over a 10,000-year period. The spatial and temporal flux of these three nuclides from the vadose zone is applied as a source term for the three-dimensional saturated zone model of the main aquifer that underlies the site. The movement of these nuclides in the aquifer to a downstream location is calculated, and aquifer concentrations are converted to doses. Doses related to aquifer concentrations are six or more orders of magnitude lower than allowable Department of Energy performance objectives for low-level radioactive waste sites. Numerical studies were used to better understand vadose-zone flow through the dry mesa-top environment at Area G. These studies helped define the final model used to model flow and transport through the vadose zone. The study of transient percolation indicates that a steady flow vadose-zone model is adequate for computing contaminant flux to the aquifer. The fracture flow studies and the investigation of the effect of basalt and pumice properties helped us define appropriate hydrologic properties for the modeling. Finally, the evaporation study helped to justify low infiltration rates.

Kay H. Birdsell; Kathleen M. Bower; Andrew V. Wolfsberg; Wendy E. Soll; Terry A. Cherry; Tade W. Orr

1999-07-01T23:59:59.000Z

251

LDRD final report: Physical simulation of nonisothermal multiphase multicomponent flow in porous media  

Science Conference Proceedings (OSTI)

This document reports on the accomplishments of a laboratory-directed research and development (LDRD) project whose objective was to initiate a research program for developing a fundamental understanding of multiphase multicomponent subsurface transport in heterogeneous porous media and to develop parallel processing computational tools for numerical simulation of such problems. The main achievement of this project was the successful development of a general-purpose, unstructured grid, multiphase thermal simulator for subsurface transport in heterogeneous porous media implemented for use on massively parallel (MP) computers via message-passing and domain decomposition techniques. The numerical platform provides an excellent base for new and continuing project development in areas of current interest to SNL and the DOE complex including, subsurface nuclear waste disposal and cleanup, groundwater availability and contamination studies, fuel-spill transport for accident analysis, and DNAPL transport and remediation.

Martinez, M.J.; Hopkins, P.L.; Shadid, J.N.

1997-07-01T23:59:59.000Z

252

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

253

Direct Numerical Simulation of Surfactant-Stabilized Emulsions Morphology and Shear Viscosity in Starting Shear Flow  

SciTech Connect

A 3D lattice Boltzmann model for two-phase flow with amphiphilic surfactant was used to investigate the evolution of emulsion morphology and shear stress in starting shear flow. The interfacial contributions were analyzed for low and high volume fractions and varying surfactant activity. A transient viscoelastic contribution to the emulsion rheology under constant strain rate conditions was attributed to the interfacial stress. For droplet volume fractions below 0.3 and an average capillary number of about 0.25, highly elliptical droplets formed. Consistent with affine deformation models, gradual elongation of the droplets increased the shear stress at early times and reduced it at later times. Lower interfacial tension with increased surfactant activity counterbalanced the effect of increased interfacial area, and the net shear stress did not change significantly. For higher volume fractions, co-continuous phases with a complex topology were formed. The surfactant decreased the interfacial shear stress due mainly to advection of surfactant to higher curvature areas. Our results are in qualitative agreement with experimental data for polymer blends in terms of transient interfacial stresses and limited enhancement of the emulsion viscosity at larger volume fractions where the phases are co-continuous.

Roar Skartlien; Espen Sollum; Andreas Akselsen; Paul Meakin

2012-07-01T23:59:59.000Z

254

Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus  

E-Print Network (OSTI)

As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, the variable air volume (VAV) system and the fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air conditioning (HVAC) systems. Our objective is to examine the energy consumption of the VRF system applied to office buildings and make suggestions for evaluating and making decisions on HVAC systems in the early stages of building design. Simulation results show that the energy-saving potential of the VRF system is expected to achieve 22.2 percent and 11.7 percent, compared to the VAV system and the FPFA system, respectively. An energy-usage breakdown of electricity end-users in various systems is also presented.

Zhou, Y.; Wu, J.; Wang, R.; Shiochi, S.

2006-01-01T23:59:59.000Z

255

Environmentally Assisted Cracking Laboratory - Nuclear Engineering...  

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

internal components are studied in simulated light water reactor (LWR) environments. Two hot-cell test facilities are used to develop experimental data on the irradiation assisted...

256

NUMERICAL FLOW AND TRANSPORT SIMULATIONS SUPPORTING THE SALTSTONE FACILITY PERFORMANCE ASSESSMENT  

SciTech Connect

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

Flach, G.

2009-02-28T23:59:59.000Z

257

Numerical Simulation of the Flow Field in 3D Eccentric Annular and 2D Centered Labyrinth Seals for Comparison with Experimental LDA Data  

E-Print Network (OSTI)

The flow field in an annular seal is simulated for synchronous circular whirl orbits with 60Hz whirl frequency and a clearance/radius ratio of 0.0154 using the Fluent Computational Fluid Dynamics (CFD) code. Fluent's Moving Reference Frame model (MRF) is used to render the flow quasi-steady by making transformations to a rotating frame. The computed flow fields for velocity, pressure and shear stress measurements are compared with the experimental data of Winslow, Thames and Cusano. The CFD predictions are found to be in good agreement with the experimental results. The present CFD methodology can be extended to other whirl frequencies and clearances. The dynamic wall pressure distributions in an annular seal for non-circular whirl orbits were obtained using CFD. The simulations were performed using a time dependant solver utilizing Fluent's Dynamic Mesh model and User Defined Functions (UDFs). The wall pressure distributions obtained from the simulations are compared with data of Cusano. The CFD simulations over predicted the pressure field when compared to experimental results however the general trends in pressure contours are similar. The flow fields for varying rotor eccentricities are also studied by performing coordinate transformations and rendering the flow quasi-steady at set eccentricities using Fluent's MRF model. The computed velocity and pressure fields are compared with the time dependant solution obtained using Fluent's Dynamic Mesh model and UDFs for the same eccentricity. Good agreement in the velocity fields is obtained; however the pressure fields require further investigation. 2D Labyrinth seal simulations were performed for comparisons with experimental LDA data from Johnson. The velocity fields match the experimental LDA data to a fair degree of extent; however, Fluent simulations under predicted the secondary recirculation zones in Labyrinth Backward Swirl (LBS) case.

Vijaykumar, Anand

2010-12-01T23:59:59.000Z

258

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

E-Print Network (OSTI)

multiphase fluid flow, heat transfer, and deformation in fractured porousmultiphase fluid flow, heat transfer and deformation in porousmultiphase flow of brine and gas through saline media. Transport in Porous

Rutqvist, J.

2011-01-01T23:59:59.000Z

259

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

fluid flow and heat-transfer processes. The physicalcoupled fluid-flow and heat-transfer processes has proven toin which flow and heat transfer processes along drifts are

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

260

Numerical simulation of single-phase and multiphase non-Darcy flow in porous and fractured reservoirs  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow of single-phase and multi-phase fluids in porous and fractured media.

Wu, Yu-Shu

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Large-Eddy Simulation of Flow and Pollutant Transport in Street Canyons of Different Building-Height-to-Street-Width Ratios  

Science Conference Proceedings (OSTI)

This study employs a large-eddy simulation technique to investigate the flow, turbulence structure, and pollutant transport in street canyons of building-height-to-street-width (aspect) ratios of 0.5, 1.0, and 2.0 at a Reynolds number of 12 000 ...

Chun-Ho Liu; Mary C. Barth; Dennis Y. C. Leung

2004-10-01T23:59:59.000Z

262

Large-Eddy Simulations of Air Flow and Turbulence within and around Low-Aspect-Ratio Cylindrical Open-Top Chambers  

Science Conference Proceedings (OSTI)

The flow around cylindrical open-top chambers (OTCs) with aspect ratios (i.e., height-to-diameter ratios) much less than unity is investigated using a large-eddy simulation (LES) model. The solid structures are represented using the immersed ...

Philip Cunningham; Rodman R. Linn; Eunmo Koo; Cathy J. Wilson

2013-08-01T23:59:59.000Z

263

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

264

Numerical simulation of the air flow field in a laboratory fume hood using the CFD-ACE(TM) computational fluid dynamics code  

E-Print Network (OSTI)

The purpose of this research was the numerical simulation of the air flow field within a standard laboratory fume hood using the k-6 turbulence model. The study investigated the flow field at different sash openings. The results of the computation realized information on the hood entry losses and other design parameters that are of interest to the users, designers and owners of fume hoods. After the specification of the problem and generation of the mesh, the modeled hood was simulated using CFD-ACE TM , a commercial computational fluid dynamics software package. The code is based on the finite volume method. In defining the grid, due care was exercised in maintaining the cell aspect ratio and grid orthogonality within the recommended limits. The air flow patterns at full open sash compared favorably with experimental results. The results at lowered sash revealed air flow characteristics and slot volume flows that were not reported in previously published literature on fume hoods. These results along with smaller hood entry losses confirmed the better performance of fume hoods at sash openings that are less than half open. Further, comparison between the computed volume flow rates and published design data was favorable.

D'Sousa, Cedric Benedict

1997-01-01T23:59:59.000Z

265

The TOUGH codes - a family of simulation tools for multiphase flow and transport processes in permeable media  

E-Print Network (OSTI)

Multiphase Tracer Transport in Heterogeneous Fractured PorousMultiphase Flow and Multicomponent Transport in Porous and

Pruess, Karsten

2003-01-01T23:59:59.000Z

266

NETL: Discrete Fracture Reservoir Simulation Software  

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

Discrete Fracture Reservoir Simulation FRACGENNFFLOW Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, a fractured reservoir modeling software developed by the...

267

Numerical Simulation of Inter-basin Groundwater Flow into Northern Yucca Flat, Nevada National Security Site, Using the Death Valley Regional Flow System Model  

SciTech Connect

Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.

Pohlmann Karl,Ye Ming

2012-03-01T23:59:59.000Z

268

Overseas Assistance  

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

Vienna U.S. Vienna Vienna, Austria Other Information U.S. Dept. of State U.S. Dept. of Energy IAEA NRC Overseas Assistance The United States encourages U.S. citizens to take...

269

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

1985) for fluid and heat flow in fractured porous media. Theflows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

270

Near-Term Effects of the Lower Atmosphere in Simulated Northwest Flow Snowfall Forced over the Southern Appalachians  

Science Conference Proceedings (OSTI)

Northwest flow snowfall (NWFS) impacts the southern Appalachian Mountains after the upper-level trough has departed from the region, when moist northwesterly flow near the ground is lifted after encountering the mountains. Snowfall associated with ...

Douglas K. Miller

2012-10-01T23:59:59.000Z

271

Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas  

E-Print Network (OSTI)

Reservoir Flow of Carbon Dioxide and Variable Salinityproduction, geologic carbon dioxide sequestration, nucleardeveloped for geologic carbon dioxide sequestration studies,

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

272

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part II: Flow Structure and Heat Budgets  

Science Conference Proceedings (OSTI)

This paper analyzes the three-dimensional flow structure and the heat budget in a typical medium-sized and steep Alpine valley—the Riviera Valley in southern Switzerland. Aircraft measurements from the Mesoscale Alpine Programme (MAP)-Riviera ...

Andreas P. Weigel; Fotini K. Chow; Mathias W. Rotach; Robert L. Street; Ming Xue

2006-01-01T23:59:59.000Z

273

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.fluid flow, mass transport, and heat-transfer processes through porous and fractured media.

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

274

House Simulation Protocols Report  

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

Building America's House Simulation Protocols report is designed to assist researchers in tracking the progress of multiyear, whole-building energy reduction against research goals for new and...

275

Numerical Simulation Of Gas-Droplet Flow Around A Nozzle In A Cylindrical Chamber Using A Lagrangian Model Based On A Multigrid Navier-Stokes Solver  

E-Print Network (OSTI)

A numerical simulation of an upward directed, 2-- dimensional, turbulent gas--droplet flow around an axisymmetric nozzle in a cylindrical chamber was made. We use a Lagrangian method, where trajectories of many droplets are calculated from the equations of motion along with the continuity and momentum equations of fluid. Strong coupling effects between the two phases are dealt with. Special algorithms were introduced for particle tracking and interpolation of the fluid flow data at the particle location on the numerical grid, which use multigrid structure for improvement of the speed of droplet trajectory calculation. The Lagrangian solver for the calculation of the trajectory and particle momentum source term was parallelised on a workstation cluster using a host--node programming model. The resulting droplet and fluid velocities at different cross sections of the cylindrical chamber are reported and compared with measurements. 2. INTRODUCTION In many engineering flow situations par...

Thomas Frank; Ingvelde Schulze

1994-01-01T23:59:59.000Z

276

Potential Impacts of Leakage from Black Rock Reservoir on the Hanford Site Unconfined Aquifer: Initial Hypothetical Simulations of Flow and Contaminant Transport  

Science Conference Proceedings (OSTI)

Initial scoping calculations of the unconfined aquifer at the Hanford Site were carried out for the U.S. Bureau of Reclamation (USBR) to investigate the potential impacts on the Hanford unconfined aquifer that would result from leakage from the proposed Black Rock Reservoir to the west. Although impacts on groundwater flow and contaminant transport were quantified based on numerical simulation results, the investigation represented a qualitative assessment of the potential lateral recharge that could result in adverse effects on the aquifer. Because the magnitude of the potential leakage is unknown, hypothetical bounding calculations were performed. When a quantitative analysis of the magnitude of the potential recharge from Black Rock Reservoir is obtained, the hydrologic impacts analysis will be revisited. The analysis presented in this report represents initial bounding calculations. A maximum lateral recharge (i.e., upland flux) was determined in the first part of this study by executing steady-state flow simulations that raised the water table no higher than the elevation attained in the Central Plateau during the Hanford operational period. This metric was selected because it assumed a maximum remobilization of contaminants that existed under previous fully saturated conditions. Three steady-state flow fields were then used to analyze impacts to transient contaminant transport: a maximum recharge (27,000 acre-ft/yr), a no additional flux (365 acre-ft/yr), and an intermediate recharge case (16,000 acre-ft/yr). The transport behavior of four radionuclides was assessed for a 300 year simulation period with the three flow fields. The four radionuclides are tritium, iodine-129, technetium-99, and uranium-238. Transient flow and transport simulations were used to establish hypothetical concentration distributions in the subsurface. Using the simulated concentration distributions in 2005 as initial conditions for steady-state flow runs, simulations were executed to investigate the relative effects on contaminant transport from the increased upland fluxes. Contaminant plumes were analyzed for 1) peak concentrations and arrival times at downstream points of compliance, 2) the area of the aquifer contaminated at or above the drinking water standard (DWS), and 3) the total activity remaining in the domain at the end of the simulation. In addition to this analysis, unit source release simulations from a hypothetical tracer were executed to determine relative travel times from the Central Plateau. The results of this study showed that increases in the lateral recharge had limited impact on regional flow directions but accelerated contaminant transport. Although contaminant concentrations may have initially increased for the more mobile contaminants (tritium, technetium-99, and iodine-129), the accelerated transport caused dilution and a more rapid decline in concentrations relative to the Base Case (no additional flux). For the low-mobility uranium-238, higher lateral recharge caused increases in concentration, but these concentrations never approached the DWS. In this preliminary investigation, contaminant concentrations did not exceed the DWS study metric. With the increases in upland fluxes, more mass was transported out of the aquifer, and concentrations were diluted with respect to the base case where no additional flux was considered.

Freedman, Vicky L.

2008-01-30T23:59:59.000Z

277

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

or chemical species in a multiphase porous medium system canand radiation in a multiphase, multicomponent, porous mediummultiphase flow, multicomponent transport, and heat transfer in porous

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

278

Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas  

E-Print Network (OSTI)

the viscosity of crude oil systems, J. Pet. Tech. (Sep. ),gases released from the BP oil well blowout, Natureof reservoir depletion and oil flow from the Macondo well

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

279

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

Flow, Transport, and Heat Transfer in Porous and Fracturedtransport, and heat transfer in porous and fracturedflow, chemical transport, and heat transfer in rock. These

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

280

Assisted fusion  

E-Print Network (OSTI)

A model of nuclear fusion consisting of a wave packet impinging into a well located between square one dimensional barriers is treated analytically. The wave function inside the well is calculated exactly for the assisted tunneling induced by a perturbation mimicking a constant electric field with arbitrary time dependence. Conditions are found for the enhancement of fusion.

German Kälbermann

2009-10-19T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Numerical Simulation of Gas/Solid Flow in a Novel Annular Spouted Bed with Multiple Gas Nozzles  

Science Conference Proceedings (OSTI)

A novel annular spouted bed with multiple gas nozzles, has been proposed for dryness, pyrolysis, and gasification of coal particulates. It consists of two homocentric upright cylinders with some annularly located spouting gas nozzles between inner and ... Keywords: gas/solid flow, CFD, Eulerian multiphase model, kinetic theory of granular flow, annular spouted bed

Gong Xi-wu; Hu Guo-xin; Zhou Hai-jiang; Shi Qian

2009-10-01T23:59:59.000Z

282

A ghost fluid, level set methodology for simulating multiphase electrohydrodynamic flows with application to liquid fuel injection  

Science Conference Proceedings (OSTI)

In this paper, we present the development of a sharp numerical scheme for multiphase electrohydrodynamic (EHD) flows for a high electric Reynolds number regime. The electric potential Poisson equation contains EHD interface boundary conditions, which ... Keywords: Conservative level set, DNS, Electrohydrodynamics, Ghost fluid method, Multiphase flow, Primary atomization

B. P. Van Poppel; O. Desjardins; J. W. Daily

2010-10-01T23:59:59.000Z

283

Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain  

E-Print Network (OSTI)

mesoscale simulations for wind energy applications, in Fallin Proceedings of the American Wind Energy Association WindWorkshop, American Wind Energy Association, Washington, DC,

Lundquist, Katherine Ann

2010-01-01T23:59:59.000Z

284

FINANCIAL ASSISTANCE  

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

FINANCIAL ASSISTANCE FINANCIAL ASSISTANCE FUNDING OPPORTUNITY ANNOUNCEMENT U.S. Department of Energy and Government of India U.S.-India Joint Clean Energy Research and Development Center Funding Opportunity Number: DE-FOA-0000506 Announcement Type: Initial CFDA Number: 81.087 Issue Date: May 16, 2011 Question Due Date: No later than July 25, 2011 Application Due Date: August 16, 2011 Submit Application to the following e-mail addresses: JCERDC@HQ.DOE.GOV (US) and JCERDC@INDOUSSTF.ORG (India) 2 TABLE OF CONTENTS PART I - FUNDING OPPORTUNITY DESCRIPTION A. Summary B. Joint Clean Energy Research and Development Center C. Center Structure & Governance D. Role of Consortia E. DOE Funding F. Government of India Funding G. Team Arrangements

285

Interactions between Gravity Waves and Planetary-Scale Flow Simulated by the GFDL “SKYHI” General Circulation Model  

Science Conference Proceedings (OSTI)

In order to study interactions between gravity waves and planetary flow in the middle atmosphere, a 3° latitude by 3.6° longitude version of the 40-level GFDL “SKYHI” general circulation model is analyzed using bihourly sampled output data.

S. Miyahara; Y. Hayashi; J. D. Mahlman

1986-09-01T23:59:59.000Z

286

A locally conservative variational multiscale method for the simulation of porous media flow with multiscale source terms  

E-Print Network (OSTI)

Multiscale phenomena are ubiquitous to flow and transport in porous media. They manifest themselves through at least the following three facets: (1) effective parameters in the governing equations are scale dependent; (2) ...

Dub, Francois-Xavier

2008-01-01T23:59:59.000Z

287

Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas  

E-Print Network (OSTI)

released from the BP oil well blowout, Nature Geoscience, 4:for the Deepwater Horizon /Macondo Well oil spill. Flow Ratecolumn of oil and gas in the well, it would imply the

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

288

A Transient Numerical Simulation of Perched Ground-Water Flow at the Test Reactor Area, Idaho National Engineering and Environmental Laboratory, Idaho, 1952-94  

SciTech Connect

Studies of flow through the unsaturated zone and perched ground-water zones above the Snake River Plain aquifer are part of the overall assessment of ground-water flow and determination of the fate and transport of contaminants in the subsurface at the Idaho National Engineering and Environmental Laboratory (INEEL). These studies include definition of the hydrologic controls on the formation of perched ground-water zones and description of the transport and fate of wastewater constituents as they moved through the unsaturated zone. The definition of hydrologic controls requires stratigraphic correlation of basalt flows and sedimentary interbeds within the saturated zone, analysis of hydraulic properties of unsaturated-zone rocks, numerical modeling of the formation of perched ground-water zones, and batch and column experiments to determine rock-water geochemical processes. This report describes the development of a transient numerical simulation that was used to evaluate a conceptual model of flow through perched ground-water zones beneath wastewater infiltration ponds at the Test Reactor Area (TRA).

B. R. Orr (USGS)

1999-11-01T23:59:59.000Z

289

Hydrogen Assisted Cracking  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking (EAC): Laboratory Research and Field Experiences: Hydrogen Assisted Cracking Program Organizers: Suresh Divi, TIMET

290

A four-equation two-phase flow model for sodium boiling simulation of LMFBR fuel assemblies  

E-Print Network (OSTI)

A three-dimensional numerical model for the simulation of sodium boiling transients has been developed. The model uses mixture mass and energy equations, while employing a separate momentum equation for each phase. Thermal ...

Schor, Andrei L.

1982-01-01T23:59:59.000Z

291

The Meridional Flow of Source-Driven Abyssal Currents in a Stratified Basin with Topography. Part II: Numerical Simulation  

Science Conference Proceedings (OSTI)

A numerical simulation is described for source-driven abyssal currents in a 3660 km × 3660 km stratified Northern Hemisphere basin with zonally varying topography. The model is the two-layer quasigeostrophic equations, describing the overlying ...

Gordon E. Swaters

2006-03-01T23:59:59.000Z

292

Evaluation of Turbulence Closure Models for Large-Eddy Simulation over Complex Terrain: Flow over Askervein Hill  

Science Conference Proceedings (OSTI)

The evaluation of turbulence closure models for large-eddy simulation (LES) has primarily been performed over flat terrain, where comparisons with theory and observations are simplified. The authors have previously developed improved closure ...

Fotini Katopodes Chow; Robert L. Street

2009-05-01T23:59:59.000Z

293

Variable Density Flow Modeling for Simulation Framework for Regional Geologic CO{sub 2} Storage Along Arches Province of Midwestern United States  

SciTech Connect

The Arches Province in the Midwestern U.S. has been identified as a major area for carbon dioxide (CO{sub 2}) storage applications because of the intersection of Mt. Simon sandstone reservoir thickness and permeability. To better understand large-scale CO{sub 2} storage infrastructure requirements in the Arches Province, variable density scoping level modeling was completed. Three main tasks were completed for the variable density modeling: Single-phase, variable density groundwater flow modeling; Scoping level multi-phase simulations; and Preliminary basin-scale multi-phase simulations. The variable density modeling task was successful in evaluating appropriate input data for the Arches Province numerical simulations. Data from the geocellular model developed earlier in the project were translated into preliminary numerical models. These models were calibrated to observed conditions in the Mt. Simon, suggesting a suitable geologic depiction of the system. The initial models were used to assess boundary conditions, calibrate to reservoir conditions, examine grid dimensions, evaluate upscaling items, and develop regional storage field scenarios. The task also provided practical information on items related to CO{sub 2} storage applications in the Arches Province such as pressure buildup estimates, well spacing limitations, and injection field arrangements. The Arches Simulation project is a three-year effort and part of the United States Department of Energy (U.S. DOE)/National Energy Technology Laboratory (NETL) program on innovative and advanced technologies and protocols for monitoring/verification/accounting (MVA), simulation, and risk assessment of CO{sub 2} sequestration in geologic formations. The overall objective of the project is to develop a simulation framework for regional geologic CO{sub 2} storage infrastructure along the Arches Province of the Midwestern U.S.

Joel Sminchak

2011-09-30T23:59:59.000Z

294

Financial Assistance Certification Financial Assistance Qualification Standards  

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

Financial Assistance Certification Financial Assistance Certification Financial Assistance Qualification Standards Financial assistance award and administration in DOE is performed primarily by contract specialists. The Office of Personnel Management qualification standards for GS- 1 102 contract specialists are relevant but not fully sufficient for performing financial assistance duties. Contract specialists performing financial assistance in addition to, or in place of, acquisition duties must also meet the certification requirements established by the Financial Assistance Career Development (FACD) program. The FACD Program is built upon the skills acquired by the contract specialists in the performance of their acquisition duties and the training provided under the Contracting/Purchasing certification program.

295

Simulation: Thermodynamic  

E-Print Network (OSTI)

(by selectively reflecting), so system energy stays constant. -- Heat is generated by viscous action corresponds to vortex generation in similar fluid mechanical situations. But the high flow speed#12; ' & $ % Coupling Continuum to Molecular Dynamics Simulation: Reflecting Particle Method

Li, Ju

296

Markov Random Field Models for High-Dimensional Parameters in Simulations of Fluid Flow in Porous Media  

E-Print Network (OSTI)

is injected along with the water at the input wells and its concentration is recorded over time at the uptake on the solution to the forward problem, i.e. determining the flow of water when the physical characteristics. It is this inverse problem that we address in this paper. A review of the inverse problem can be found in Yeh (1986

West, Mike

297

Markov Random Field Models for HighDimensional Parameters in Simulations of Fluid Flow in Porous Media  

E-Print Network (OSTI)

is injected along with the water at the input wells and its concentration is recorded over time at the uptake on the solution to the forward problem, i.e. determining the flow of water when the physical characteristics. It is this inverse problem that we address in this paper. A review of the inverse problem can be found in Yeh (1986

West, Mike

298

Numerical simulation of unsteady flow in centrifugal pump impeller at off-design condition by hybrid RANS/LES approaches  

Science Conference Proceedings (OSTI)

A new kind of hybrid RANS/LES turbulence modeling method - SST based SAS model is first time used for studying the stall phenomena in a centrifugal pump impeller at off-design condition in present paper. The previous reported “two channel” ... Keywords: centrifugal impeller, flow visualization, hybrid RANS/LES, off-design condition

Wei Zhang; Yunchao Yu; Hongxun Chen

2009-08-01T23:59:59.000Z

299

Advanced Simulation Capability for Environmental Management  

Multi-Process High Performance Computing Simulator Modular simulation capability for barrier and waste form degradation, multiphase flow and reactive ...

300

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

Note: This page contains sample records for the topic "flow simulation assisted" 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

Dynamics and energetics of the cloudy boundary layer in simulations of off-ice flow in the marginal ice zone  

E-Print Network (OSTI)

kinetic energy even in the present case where very strong surface heat fluxes occur. Ice-phase. Inclusion of the ice phase significantly affected the radiative budget as compared to purely liquid clouds, illustrating the importance of ice-phase­radiative couplings for accurate simulations of arctic clouds

Harrington, Jerry Y.

302

Quasi-Lagrangian Large Eddy Simulations of Cross-Equatorial Flow in the East Pacific Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Using a large eddy simulation (LES), the atmospheric boundary layer (ABL) is numerically modeled along 95°W from 8°S to 4°N during boreal autumn, and compared to observations from the East Pacific Investigation of Climate Processes in the Coupled ...

S. P. de Szoeke; C. S. Bretherton

2004-08-01T23:59:59.000Z

303

Turbine blade platform film cooling with simulated stator-rotor purge flow with varied seal width and upstream wake with vortex  

E-Print Network (OSTI)

The turbine blade platform can be protected from hot mainstream gases by injecting cooler air through the gap between stator and rotor. The effectiveness of this film cooling method depends on the geometry of the slot, the quantity of injected air, and the secondary flows near the platform. The purpose of this study was to measure the effect of the upstream vane or stator on this type of platform cooling, as well as the effect of changes in the width of the gap. Film cooling effectiveness distributions were obtained on a turbine blade platform within a linear cascade with upstream slot injection. The width of the slot was varied as well as the mass flow rate of the injected coolant. Obstacles were placed upstream to model the effect of the upstream vane. The coolant was injected through an advanced labyrinth seal to simulate purge flow through a stator-rotor seal. The width of the opening of this seal was varied to simulate the effect of misalignment. Stationary rods were placed upstream of the cascade in four phase locations to model the unsteady wake formed at the trailing edge of the upstream vane. Delta wings were also placed in four positions to create a vortex similar to the passage vortex at the exit of the vane. The film cooling effectiveness distributions were measured using pressure-sensitive paint (PSP). Reducing the width of the slot was found to decrease the area of coolant coverage, although the film cooling effectiveness close to the slot was slightly increased. The unsteady wake was found to have a trivial effect on platform cooling, while the passage vortex from the upstream vane may significantly reduce the film cooling effectiveness.

Blake, Sarah Anne

2007-05-01T23:59:59.000Z

304

A TOUGH2 equation-of-state module for the simulation of two-phase flow of air, water, and a miscible gelling liquid  

SciTech Connect

The injection of grout into the subsurface can be used to encapsulate contaminated regions of an aquifer, or to form underground barriers for the isolation of contaminant sources and to prevent the spreading of existing plumes. This requires identifying grouts, or barrier fluids, which when injected into the subsurface exhibit a large increase in viscosity and eventually solidify, sealing the permeable zones in the aquifer. Simulation and modeling analysis are indispensable tools for designing the injection and predicting the performance of the barrier. In order to model flow and transport in such systems, the thermophysical properties of the fluid mixtures have to be provided, and the governing mass- and energy-balance equations for multiphase flow in porous media have to be solved numerically. The equation-of-state module EOS11 described herein is an extension of the EOS7 module of the TOUGH2 code for flow of saline water and air. In the modeling approach, the chemical grout is treated as a miscible fluid the viscosity of which is a function of time and concentration of the gelling agent in the pore water. If a certain high viscosity is reached and the movement of the grout plume ceases, the gel is assumed to solidify, leading to a new porous medium with changed soil characteristics, i.e. reduced porosity and permeability, increased capillary strength for a given water content, and changed initial saturation distribution.

Finsterle, S.; Moridis, G.J.; Pruess, K. [Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.

1994-05-01T23:59:59.000Z

305

Visualization of Fluid Flow  

Science Conference Proceedings (OSTI)

... Goujon and J. Devaney, Large Scale Simulations of Single and Multi- Component Flow in Porous Media in Proceedings of SPIE: The International ...

2010-12-15T23:59:59.000Z

306

Advanced Manufacturing Office: Technical Assistance  

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

Assistance on Twitter Bookmark Advanced Manufacturing Office: Technical Assistance on Google Bookmark Advanced Manufacturing Office: Technical Assistance on Delicious Rank...

307

Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at {radical}(s{sub NN})=200 GeV  

Science Conference Proceedings (OSTI)

Using the (2+1)-dimensional viscous hydrodynamic code vish2+1[H. Song and U. Heinz, Phys. Lett. B 658, 279 (2008); H. Song and U. Heinz, Phys. Rev. C 77, 064901 (2008); H. Song, Ph. D. thesis, The Ohio State University, 2009], we present systematic studies of the dependence of pion and proton transverse-momentum spectra and their elliptic flow in 200A GeV Au+Au collisions on the parameters of the hydrodynamic model (thermalization time, initial entropy density distribution, decoupling temperature, equation of state, and specific shear viscosity {eta}/s). We identify a tension between the slope of the proton spectra, which (within hydrodynamic simulations that assume a constant shear viscosity to entropy density ratio) prefer larger {eta}/s values, and the slope of the p{sub T} dependence of charged hadron elliptic flow, which prefers smaller values of {eta}/s. Changing other model parameters does not appear to permit dissolution of this tension.

Shen Chun; Heinz, Ulrich; Huovinen, Pasi; Song, Huichao [Department of Physics, Ohio State University, Columbus, Ohio 43210-1117 (United States); Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt am Main (Germany); Department of Physics, Ohio State University, Columbus, Ohio 43210-1117 (United States) and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS70R0319, Berkeley, California 94720 (United States)

2010-11-15T23:59:59.000Z

308

Flow instabilities in the core and the coolant circuit of advances low-boiling light water reacto: classification of causes and development of simulator for the future analysis  

E-Print Network (OSTI)

The coolant flow instability, apparent in the coolant mass flow fluctuations in the separate parallel heating channels and also in a closed loop of the primary circuit under some operating conditions, is observed in the core fuel assemblies of light water reactors. In some ways this phenomenon is identical with the fluctuations in the once-through steam generators pipes, and changes of the coolant mass flows and length of flow patterns are initiating this phenomenon. The parameters at the core output and the secondary circuit parameters have influence on each other. These parameter changes have significant influences on the operating processes, operating and control algorithms, operating and control system design, and reliability of the operating power plant's machines and equipment. Changes of heating surface temperatures, displacement borders of the flow patterns, and critical heat flux entail changes of the coolant flow parameters, finally causing changes of the initial primary system parameters due to closed loop system feedback. In turn, these cause over-circuit instability in the reactor. Core power generation changes are carried out by means of influencing the nuclear fission process through changing the multiplication factor. Additionally, these local side-to-side power irregularities in sub-zones may appear due to the influence of various hydrodynamic instabilities. The local side-to-side power in these sub-zones may differ significantly from each other. The aforesaid arguments are correct for the both light water reactor types. But, as is shown by our investigations and operational practice of low-boiling reactors, behavior of the core-circuit hydrodynamic system is significantly different from its behavior in the boiling or pressurized reactors with pumping circulation. The coolant flow regimes in typical reactors are defined through pump operating regimes and are not adjustable inside a certain power range. The objective of this thesis is to understand more precisely the influence and the nature of these phenomena. After analyzing the problem from different points of view and showing the necessity of its comprehensive understanding, we present recommendations for engineering solutions and plans for further investigations. We will try to determine limits of their reliable practical application with modern low-to-medium power reactor design and investigate this dynamic system behavior. Finally, it is necessary to take into consideration not separate phenomena, but their complex influence on the whole primary system (i.e. a kind of macro-system is examined without being separated into its individual elements). But, the analysis of every phenomenon is fulfilled separately and a process of formation of a block-scheme, consisting of several sub-systems, is given in this thesis. The final block-scheme is presented as a simulator model, taking into consideration design components chosen for the analysis of system dynamics as the first step of model development.

Rezvyi, Aleksey

2002-01-01T23:59:59.000Z

309

Section K: ENERGY ASSISTANCE  

U.S. Energy Information Administration (EIA)

Children (AFDC), Temporary Assistance for Needy Families (TANF), Supplemental Security Income (SSI),

310

Financial Assistance | Department of Energy  

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

Assistance Assistance Financial Assistance Memo from Deputy Secretary Poneman to DOE Contractor or Financial Assistance Recipient (March 4, 2013) Financial Assistance Regulations Department of Energy Financial Assistance Regulation, 10 CFR 600 New Restrictions on Lobbying, 10 CFR Part 601 Epidemiology & Other Health Studies, 10 CFR Part 602 Technology Investment Agreements, 10 CFR 603 Office of Science Financial Assistance Program, 10 CFR Part 605 Financial Assistance Policy and Guidance Department of Energy Financial Assistance Letters Active Financial Assistance Letters Archived Financial Assistance Letters Department of Energy Guide to Financial Assistance Merit Review Guide for Financial Assistance and Unsolicited Proposals Financial Assistance Forms and Information for Applicants and Recipients

311

ARM - Instrument - assist  

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

govInstrumentsassist govInstrumentsassist Documentation ASSIST : Instrument Mentor Monthly Summary (IMMS) reports ASSIST : Data Quality Assessment (DQA) reports ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST) Instrument Categories Radiometric The Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST), like the AERI, measures infrared spectral zenith radiance at high spectral resolution. Output Datastreams assistch1 : Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST): channel 1 data assistch2 : Atmospheric Sounder Spectrometer for Infrared Spectral Technology (ASSIST): channel 2 data

312

Center Scientists Assist Mexico  

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

Center Scientists Assist Mexico The U.S. Agency for International Development (USAID) has approved funds for LBL to provide technical assistance to Mexico's Comisi-n Nacional de...

313

Environmentally Assisted Cracking: Nuclear  

Science Conference Proceedings (OSTI)

About this Symposium. Meeting, Materials Science & Technology 2014. Symposium, Environmentally Assisted Cracking: Nuclear. Sponsorship. Organizer(s) ...

314

Network Electricity Use Associated with Wireless Personal Digital Assistants  

E-Print Network (OSTI)

Network Electricity Use Associated with Wireless Personal Digital Assistants Jonathan Koomey1 the widely cited claim that the network electricity use associated with a wireless personal digital assistant PDA is equal to the electricity consumed by a refrigerator. It compiles estimates of the data flows

Kammen, Daniel M.

315

A filtered mass density function approach for modeling separated two-phase flows for LES II: Simulation of a droplet laden  

E-Print Network (OSTI)

and evaporation/reaction of dilute particulate­gas two-phase flows is extremely impor- tant in many natural the importance of variations in composition space in the phase-coupling terms. � 2008 Elsevier Ltd. All rights reserved. Keywords: Two-phase flow; FDF methods; Temporal mixing layer; LES; Droplet gas flow 1

DesJardin, Paul E.

316

Technical Assistance | Department of Energy  

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

Resources Technical Assistance Technical Assistance Education and Training Energy Resource Library Funding Opportunities Military Initiative Newsletter Roundtables START Program...

317

Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide  

Science Conference Proceedings (OSTI)

The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na{sub 2}O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks.

DH Bacon; MD White; BP McGrail

2000-03-07T23:59:59.000Z

318

Office of Security Assistance  

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

Security Security Home Sub Offices › Security Policy › Security Assistance › Departmental Personnel Security Mission & Functions › Security Policy › Security Assistance › Departmental Personnel Security Human Reliability Program (HRP) Guidance Documents Security Technology Information Archive (STIA) Related Links › DOE › DOE CIO › NNSA › DOE CFO › NTC › S&S PIR Contact Us HSS Logo Director's Perspective Welcome to the Office of Security Assistance Samuel N. Callahan, Director Mission and Functions The Office of Health, Safety, and Security (HSS) created the Office of Security Assistance Program to provide timely technical assistance and system support to field and Headquarters elements to enhance site security programs, upon request. The program is comprised of technologists and subject matter experts from all security disciplines including Program Management, Protection Program Operations, Information Security, Materials Control and Accountability, and Personnel Security. HSS is committed to building a security assistance program to serve the interests of the Department based upon the needs of our customers - with emphasis on customer-focus and meeting multi-disciplinary security needs. In Fiscal Year 2007, HSS performed extensive assistance activities at the request of DOE/NNSA program offices and field sites. The activities ranged from special and routine site survey assistance, physical and technical security inspections in support of the Office of Intelligence, Vulnerability Assessment and Design Basis Threat (DBT) implementation assistance, third-party, adversary support, and DBT implementation and planning validation activities associated with the Site Assistance Visits and Technology Assistance Visits. The security assistance provided to our customers included technical expertise tailored to augment site capabilities in critical fields.

319

Graduate Research Assistant Program  

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

Students Graduate Program Graduate Research Assistant Program Point your career towards LANL: work with the best minds on the planet in an inclusive environment that is rich in...

320

Assistant Secretary for Procurement and Assistance Management,  

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

This Personal Property Letter (PPL) is issued by the Deputy Assistant Secretary for Procurement and Assistance Management, to provide assistance in the implementation of the property clause of the Department of Energy Acquisition Regulations. CITATION Public Law purpose of this initial ~PL, Number to provide guidance concerni:ng the. transfer Energy (DOE) personal property identified as necessary for economic development and located at DOE sites and facilities that are undergoing reconfiguration or . .closure, or are expected to be scheduled for termination or other significant transition due to the downsizing of the Department's nuclear weapons production mission. Back~ound. Section 3155 of Public Law 103-160, the National Defense Authorization Act for Fiscal Year 1994,

Note: This page contains sample records for the topic "flow simulation assisted" 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

Virtual assistant: an artificial agent for enhancing content acquisition: how ambient media elicit information from humans  

Science Conference Proceedings (OSTI)

In this paper, we propose a novel framework "Virtual Assistant" for enhancing content potentially procured by ambient media. The Virtual Assistant is an artificial agent simulating a human assistant shown in TV programs and prompts users to provide feedback ... Keywords: ambient media, artificial agent, content acquisition

Motoyuki Ozeki; Shunichi Maeda; Kanako Obata; Yuichi Nakamura

2008-10-01T23:59:59.000Z

322

Effect of radial transport on compressor tip clearance flow structures and enhancement of stable flow range  

E-Print Network (OSTI)

The relation between tip clearance flow structure and axial compressor stall is interrogated via numerical simulations, to determine how casing treatment can result in improved flow range. Both geometry changes and flow ...

Nolan, Sean Patrick Rock

2005-01-01T23:59:59.000Z

323

FEDERAL ASSISTANCE BUDGET INFORMATION (CONSTRUCTION) | Department...  

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

FEDERAL ASSISTANCE BUDGET INFORMATION (CONSTRUCTION) FEDERAL ASSISTANCE BUDGET INFORMATION (CONSTRUCTION) Form provides information on the federal assistance budget for...

324

Lee-Vortex Formation in Free-Slip Stratified Flow over Ridges. Part I: Comparison of Weakly Nonlinear Inviscid Theory and Fully Nonlinear Viscous Simulations  

Science Conference Proceedings (OSTI)

The formation of lee wakes and vortices is explored in the context of stratified flow with uniform basic-state wind and stability past elongated free-slip ridges.

C. C. Epifanio; D. R. Durran

2002-04-01T23:59:59.000Z

325

Lattice Boltzmann modeling of microchannel flow in slip flow regime  

Science Conference Proceedings (OSTI)

We present the lattice Boltzmann equation (LBE) with multiple relaxation times (MRT) to simulate pressure-driven gaseous flow in a long microchannel. We obtain analytic solutions of the MRT-LBE with various boundary conditions for the incompressible ... Keywords: Gas flow through microchannel, Lattice Boltzmann equation with multiple relaxation times, Slip flow

Frederik Verhaeghe; Li-Shi Luo; Bart Blanpain

2009-01-01T23:59:59.000Z

326

Assistance | Department of Energy  

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

Assistance Assistance Assistance Federal Technical Capability Program (FTCP) The Federal Technical Capability Panel (Panel) is responsible for overseeing the overall implementation of the Federal Technical Capability Program. Headquarters and field elements are responsible for implementing specific activities within the program. Some activities addressing technical capability functions apply complex-wide; for example, the Department's Policies, Orders, and Standards, which promulgate requirements and guidelines for the administration of technical training. Other mechanisms vary from site to site or between program offices. Federal Line Management Oversight of Department of Energy Nuclear Facilities This Guide provides U.S. Department of Energy (DOE) line management

327

Office of Acquisition and Assistance  

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

and Assistance Home U.S. Department of Energy - Chicago Office spacer spacer Functions Organization Requirements for Financial Assistance Awards Information for Small Businesses...

328

Technical Assistance | Department of Energy  

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

Technical Assistance Technical Assistance Technical Assistance Photo courtesy of Dennis Schroeder, NREL 18022 Photo courtesy of Dennis Schroeder, NREL 18022 The U.S. Department of Energy offers technical assistance supporting energy efficiency and renewable energy. This technical assistance can include direct advice on issues or goals, tools and maps, and training. Some select technical assistance offerings are listed below. For States and Communities The State and Local Solution Center provides states and communities with resources addressing strategic energy planning, policy, financing, data management, and technologies to help them implement successful energy efficiency and renewable energy projects. The Weatherization Assistance Program Technical Assistance Center provides

329

NGFAST: a simulation model for rapid assessment of impacts of natural gas pipeline breaks and flow reductions at U.S. state borders and import points  

Science Conference Proceedings (OSTI)

This paper describes NGfast, the new simulation and impact-analysis tool developed by Argonne National Laboratory for rapid, first-stage assessments of impacts of major pipeline breaks. The methodology, calculation logic, and main assumptions are discussed. ...

Edgar C. Portante; Brian A. Craig; Stephen M. Folga

2007-12-01T23:59:59.000Z

330

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

Amarnath, M. Blatt, Variable refrigerant flow: where, why,simulation in the variable refrigerant flow air-conditioningsimulation of the variable refrigerant flow air conditioning

Hong, Tainzhen

2010-01-01T23:59:59.000Z

331

HYDROGEN ASSISTED DIESEL COMBUSTION.  

E-Print Network (OSTI)

??In this study, the effect of hydrogen assisted diesel combustion on conventional and advanced combustion modes was investigated on a DDC/VM Motori 2.5L, 4-cylinder, turbocharged,… (more)

Lilik, Gregory

2008-01-01T23:59:59.000Z

332

Low income energy assistance  

Science Conference Proceedings (OSTI)

States are limited in their ability to manage their heating assistance programs because they normally receive funds from the Low Income Home Energy Assistance Program after the heating season has begun and after they have decided on the benefits to be provided to eligible participants. In addition, the Department of Health and Human Services does not have enough flexibility to respond to unanticipated energy cost increases that can occur as a result of unusually severe weather or fuel price increases. HHS and the states could better manage the program if (1) it were forward funded so the states would know exactly how much federal assistance they would receive before they begin handling applications for heating assistance and (2) HHS had some discretion in how funds are allocated to the states to enable it to react to unanticipated energy-related circumstances.

Not Available

1990-10-01T23:59:59.000Z

333

Compiler assisted masking  

Science Conference Proceedings (OSTI)

Differential Power Analysis (DPA) attacks find a statistical correlation between the power consumption of a cryptographic device and intermediate values within the computation. Randomization via (Boolean) masking of intermediate values breaks this statistical ... Keywords: DPA, compiler assisted cryptography, masking

Andrew Moss; Elisabeth Oswald; Dan Page; Michael Tunstall

2012-09-01T23:59:59.000Z

334

Comparison of In-Canopy Flux Footprints between Large-Eddy Simulation and the Lagrangian Simulation  

Science Conference Proceedings (OSTI)

Flux footprints for neutral shear-driven canopy flows are evaluated using large-eddy simulation (LES) and a Lagrangian stochastic (LS) model. The Lagrangian stochastic model is driven by flow statistics derived from the large-eddy simulation. LES ...

T. V. Prabha; M. Y. Leclerc; D. Baldocchi

2008-08-01T23:59:59.000Z

335

Automotive soiling simulation based on massive particle tracing  

Science Conference Proceedings (OSTI)

In the automotive industry Lattice-Boltzmann type flow solvers like PowerFlow from Exa Corporation are becoming increasingly important. In contrast to the traditional finite volume approach PowerFlow utilizes a hierachical cartesian grid for flow simulation. ...

Stefan Roettger; Martin Schulz; Wolf Bartelheimer; Thomas Ertl

2001-05-01T23:59:59.000Z

336

THE APPLICATION OF A STATISTICAL DOWNSCALING PROCESS TO DERIVE 21{sup ST} CENTURY RIVER FLOW PREDICTIONS USING A GLOBAL CLIMATE SIMULATION  

SciTech Connect

The ability of water managers to maintain adequate supplies in coming decades depends, in part, on future weather conditions, as climate change has the potential to alter river flows from their current values, possibly rendering them unable to meet demand. Reliable climate projections are therefore critical to predicting the future water supply for the United States. These projections cannot be provided solely by global climate models (GCMs), however, as their resolution is too coarse to resolve the small-scale climate changes that can affect hydrology, and hence water supply, at regional to local scales. A process is needed to ‘downscale’ the GCM results to the smaller scales and feed this into a surface hydrology model to help determine the ability of rivers to provide adequate flow to meet future needs. We apply a statistical downscaling to GCM projections of precipitation and temperature through the use of a scaling method. This technique involves the correction of the cumulative distribution functions (CDFs) of the GCM-derived temperature and precipitation results for the 20{sup th} century, and the application of the same correction to 21{sup st} century GCM projections. This is done for three meteorological stations located within the Coosa River basin in northern Georgia, and is used to calculate future river flow statistics for the upper Coosa River. Results are compared to the historical Coosa River flow upstream from Georgia Power Company’s Hammond coal-fired power plant and to flows calculated with the original, unscaled GCM results to determine the impact of potential changes in meteorology on future flows.

Werth, D.; Chen, K. F.

2013-08-22T23:59:59.000Z

337

A Dynamic hp-Adaptive Discontinuous Galerkin Method for Shallow-Water Flows on the Sphere with Application to a Global Tsunami Simulation  

Science Conference Proceedings (OSTI)

A discontinuous Galerkin model solving the shallow-water equations on the sphere is presented. It captures the dynamically varying key aspects of the flows by having the advantageous ability to locally modify the mesh as well as the order of ...

Sébastien Blaise; Amik St-Cyr

2012-03-01T23:59:59.000Z

338

Numerical simulation of three-dimensional breaking waves on a gravel slope using a two-phase flow Navier-Stokes model  

Science Conference Proceedings (OSTI)

Wave breaking is mainly a three-dimensional flow problem characterized by wave energy dissipation due to turbulence. The understanding of the wave breaking mechanism on a beach is essential in studying coastal processes. The complexity of the wave-induced ... Keywords: CFD, Porous medium, Two phase, VOF, Wave breaking

P. Higuera; M. Del Jesus; J. L. Lara; I. J. Losada; Y. Guanche; G. Barajas

2013-07-01T23:59:59.000Z

339

Technical Assistance | Department of Energy  

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

Assistance Assistance Technical Assistance Best practice-based technical assistance is provided through a combination of OE staff, and nationally-recognized experts at the Lawrence Berkeley National Laboratory, the Regulatory Assistance Project, the National Council on Electricity Policy, the National Council of State Legislatures, and the National Governors Association, and others. With these entities, the expert technical assistance is provided on an as-requested basis to State public utility commissions, State legislatures, regional State associations, regional transmission organizations/independent system operators, Federal officials, Governors' offices, State energy offices, and sometimes individual electric utilities. Technical Assistance on EPA Rules Implementation to States and the Utility

340

Ngfast : a simulation model for rapid assessment of impacts of natural gas pipeline breaks and flow reductions at U. S. state borders and import points.  

Science Conference Proceedings (OSTI)

This paper describes NGfast, the new simulation and impact-analysis tool developed by Argonne National Laboratory for rapid, first-stage assessments of impacts of major pipeline breaks. The methodology, calculation logic, and main assumptions are discussed. The concepts presented are most useful to state and national energy agencies tasked as first responders to such emergencies. Within minutes of the occurrence of a break, NGfast can generate an HTML-formatted report to support briefing materials for state and federal emergency responders. Sample partial results of a simulation of a real system in the United States are presented.

Portante, E. C.; Craig, B. A.; Folga, S.M.

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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.


341

Technical Assistance to Developers  

DOE Green Energy (OSTI)

This task supports the allowance of technical assistance to fuel-cell component and system developers as directed by the DOE. This task includes testing of novel materials and participation in the further development and validation of single cell test protocols. This task also covers technical assistance to DOE Working Groups, the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Driving Research and Innovation for Vehicle efficiency and Energy sustainability (U.S. Drive) Fuel Cell Technology Team. Assistance includes technical validation of new fuel cell materials and methods, single cell fuel cell testing to support the development of targets and test protocols, and regular advisory participation in other working groups and reviews. This assistance is made available to PEM fuel cell developers by request and DOE Approval. The objectives are to: (1) Support technically, as directed by DOE, fuel cell component and system developers; (2) Assess fuel cell materials and components and give feedback to developers; (3) Assist the DOE Durability Working Group with the development of various new material durability Testing protocols; and (4) Provide support to the U.S. Council for Automotive Research (USCAR) and the USCAR/DOE Fuel Cell Technology Team. FY2012 specific technical objectives are: (1) Evaluate novel MPL materials; (2) Develop of startup/ shutdown protocol; (3) Test the impact of hydrophobic treatment on graphite bi-polar plates; (4) Perform complete diagnostics on metal bi-polar plates for corrosion; and (5) Participate and lead efforts in the DOE Working Groups.

Rockward, Tommy [Los Alamos National Laboratory; Borup, Rodney L. [Los Alamos National Laboratory; Garzon, Fernando H. [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Spernjak, Dusan [Los Alamos National Laboratory

2012-07-17T23:59:59.000Z

342

DOE Technical Assistance Program  

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

Retrieving Customer Usage Data from Utilities Retrieving Customer Usage Data from Utilities The Parker Ranch installation in Hawaii Collection of Customer Data for Better Buildings Guidelines For Retrieving Customer Usage Data from Utility Keith Freischlag and Curtis Framel Southwest Energy Efficiency Project DOE Technical Assistance Program Team 4 - Program & Project Development & Implementation December 16, 2010 Guidelines for Retrieving Customer Usage Data from Utilities Webinar Overview * Technical Assistance Program (TAP) * Discussion of Identifying Utility Stakeholders * Discussion of Procuring Customer Usage Data * Suggestions to Streamline Data Collection Processes * Overview of Data Reporting Requirements * Q&A Guidelines for Retrieving Customer Usage Data from Utilities * Questions and discussion after presentation

343

Flow interference in bluff body wakes  

Science Conference Proceedings (OSTI)

This paper presents a two-dimensional numerical simulation of fluid flow around a couple of identical circular cylinders aligned, respectively, along and orthogonal to the main-flow direction, at several distances. A lattice-Boltzmann method (LB) is ...

Rodrigo Surmas; Luís Orlando Emerich Dos Santos; Paulo Cesar Philippi

2003-06-01T23:59:59.000Z

344

Regional Drainage Flows in the Pacific Northwest  

Science Conference Proceedings (OSTI)

An analysis of regional drainage flows in the Pacific Northwest is presented using results from a network of surface observations and a series of simulations carried out with a nested mesoscale model. The flows, which occur regularly in ...

J. C. Doran; S. Zhong

1994-06-01T23:59:59.000Z

345

Turbulent Channel Flows on a Rotating Earth  

Science Conference Proceedings (OSTI)

This paper deals with flow in a rectilinear channel on a rotating earth. The flow is directed perpendicular to the background planetary vorticity; both an analytical theory and numerical simulations are employed. The analytical approach assumes ...

Robert A. Handler; Richard P. Mied; Gloria J. Lindemann; Thomas E. Evans

2009-04-01T23:59:59.000Z

346

Two-phase flow studies  

DOE Green Energy (OSTI)

The two-phase flow program is directed at understanding the hydrodynamics of two-phase flows. The two-phase flow regime is characterized by a series of flow patterns that are designated as bubble, slug, churn, and annular flow. Churn flow has received very little scientific attention. This lack of attention cannot be justified because calculations predict that the churn flow pattern will exist over a substantial portion of the two-phase flow zone in producing geothermal wells. The University of Houston is experimentally investigating the dynamics of churn flow and is measuring the holdup over the full range of flow space for which churn flow exists. These experiments are being conducted in an air/water vertical two-phase flow loop. Brown University has constructed and is operating a unique two-phase flow research facility specifically designed to address flow problems of relevance to the geothermal industry. An important feature of the facility is that it is dedicated to two-phase flow of a single substance (including evaporation and condensation) as opposed to the case of a two-component two-phase flow. This facility can be operated with horizontal or vertical test sections of constant diameter or with step changes in diameter to simulate a geothermal well profile.

Hanold, R.J.

1983-12-01T23:59:59.000Z

347

Technology Assistance Program | Partnerships | ORNL  

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

Technology Assistance Program Technology Assistance Program Licensing Staff Search For Technologies Available Technologies Licensing Opportunity Announcements Partnerships Home | Connect with ORNL | For Industry | Partnerships | Technology Licensing | Technology Assistance Program SHARE Technology Assistance Program Electronics Research Assistance is available for small business licensees of ORNL technologies to leverage ORNL's expertise and capabilities to accelerate the commercialization of licensed technologies. The Technology Assistance Program (TAP) provides funds for ORNL science & technology staff members to consult with licensees, performing work on the company's behalf that may include such activities as the following. Production of sample materials for evaluation

348

Multiphase Flow Modeling Research  

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

Science Science Chris Guenther, Director Computational Science Division RUA Spring Meeting, Morgantown, WV March 2013 2 NETL's Multiphase Flow Science Team * The Multiphase Flow Science Team develops physics-based simulation models to conduct applied scientific research. - Development of new theory - Extensive on-site and collaborative V&V efforts and testing - Engages in technology transfer - Applies the models to industrial scale problems. 3 Why is Multiphase Flow Science Needed? * Industry is increasingly relying on multiphase technologies to produce clean and affordable energy with carbon capture. * Unfortunately, the presence of a solid phase reduces the operating capacity of a typical energy device from its original design on average by 40% [1].

349

Financial Assistance Level III 1 ACQUISITION CERTIFICATION - FINANCIAL ASSISTANCE  

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

Financial Assistance Level III 1 Financial Assistance Level III 1 ACQUISITION CERTIFICATION - FINANCIAL ASSISTANCE LEVEL III PART A - EMPLOYEE INFORMATION Name (Last, First, Middle initial)_____________________________________________ Email Address____________________________________________________________ Phone___________________________________________________________________ Agency Name ____________________________________________________________ Agency Address__________________________________________________________ Title, Series, Grade________________________________________________________ Education: Please specify degree and major: Degree: Associates: __; Bachelors __; Masters: __; Doctorate: __ Major: PART B - CERTIFICATION REQUIREMENTS

350

Knowledge Assisted Visualization: Knowledge-assisted visualization of seismic data  

Science Conference Proceedings (OSTI)

We present novel techniques for knowledge-assisted annotation and computer-assisted interpretation of seismic data for oil and gas exploration. We describe the existing procedure for oil and gas search which consists of manually extracting information ... Keywords: 2D textures, 3D textures, Illustrative visualization, Knowledge-assisted visualization, Rapid interpretation, Seismic interpretation

Daniel Patel; Řyvind Sture; Helwig Hauser; Christopher Giertsen; M. Eduard Gröller

2009-10-01T23:59:59.000Z

351

Characterizing two-phase flow relative permeabilities in chemical flooding using a pore-scale network model  

E-Print Network (OSTI)

simultaneous flow of multiphase fluids in a porous medium byin porous media-pore network models and multiphase flow,simulating multiphase flow and transport processes in porous

Liu, Qingjie; Shen, Pingping; Wu, Yu-Shu

2008-01-01T23:59:59.000Z

352

Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop  

SciTech Connect

The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

McCulloch, R.W.; MacPherson, R.E.

1983-03-01T23:59:59.000Z

353

Assistive Technology | Department of Energy  

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

The DOE Headquarters Accommodation Program was established to provide reasonable computer and related telecommunications accommodations to assist employees with disabilities....

354

Low income home energy assistance  

Science Conference Proceedings (OSTI)

The Low Income Home Energy Assistance Program provides eligible households with assistance for home energy costs. Assistance is available to (1) help families pay heating and cooling costs, (2) prevent energy cutoff in crisis situations, and (3) help families make their homes more energy efficient. This report provides background information on the program in preparation for the program's reauthorization in 1990.

Not Available

1990-10-01T23:59:59.000Z

355

Gina Pearson Assistant Administrator  

Gasoline and Diesel Fuel Update (EIA)

Gina Pearson Gina Pearson Assistant Administrator for Communications Duties Gina Pearson is the Assistant Administrator (AA) for Communications, and in this capacity provides leadership and direction to conduct the U.S. Energy Information Administration's comprehensive communications program for diverse external customer groups and agency employees. The AA for Communications is responsible for Agency communications policies and standards, the www.eia.gov website, press and media rela- tions, marketing and outreach services, energy education and literacy efforts, and the Agency's employee intranet site. Biography Since 2006, Gina Pearson has played a leadership role in the U.S. Energy Information Administration's (EIA) strategy and operations for commu- nicating information and data to Federal, State and local agencies; the

356

Chemically-Assisted Pulsed Laser-Ramjet  

SciTech Connect

A preliminary study of a chemically-assisted pulsed laser-ramjet was conducted, in which chemical propellant such as a gaseous hydrogen/air mixture was utilized and detonated with a focused laser beam in order to obtain a higher impulse compared to the case only using lasers. CFD analysis of internal conical-nozzle flows and experimental measurements including impulse measurement were conducted to evaluate effects of chemical reaction on thrust performance improvement. From the results, a significant improvement in the thrust performances was confirmed with addition of a small amount of hydrogen to propellant air, or in chemically-augmented operation.

Horisawa, Hideyuki; Kaneko, Tomoki; Tamada, Kazunobu [Department of Aeronautics and Astronautics, Tokai University, Hiratsuka, Kanagawa, 259-1292 (Japan)

2010-10-13T23:59:59.000Z

357

Plant analyzer development for high-speed interactive simulation of BWR plant transients  

SciTech Connect

Advanced modeling techniques have been combined with modern, special-purpose peripheral minicomputer technology to develop a plant analyzer which provides realistic and accurate predictions of plant transients and severe off-normal events in nuclear power plants through on-line simulations at speeds of approximately 10 times faster than actual process speeds. The new simulation technology serves not only for carrying out routinely and efficiently safety analyses, optimizations of emergency procedures and design changes, parametric studies for obtaining safety margins and for generic training but also for assisting plant operations. Five modeling principles are presented which serve to achieve high-speed simulation of neutron kinetics, thermal conduction, nonhomogeneous and nonequilibrium two-phase flow coolant dynamics, steam line acoustical effects, and the dynamics of the balance of plant and containment systems, control systems and plant protection systems. 21 refs.

Wulff, W.; Cheng, H.S.; Mallen, A.N.

1986-01-01T23:59:59.000Z

358

Development and validation of a radial inflow turbine model for simulation of the SNL S-CO2 split-flow loop.  

SciTech Connect

A one-dimensional model for a radial inflow turbine has been developed for super-critical carbon dioxide (S-CO{sub 2}) Brayton cycle applications. The model accounts for the main phenomena present in the volute, nozzle, and impeller of a single-stage turbine. These phenomena include internal losses due to friction, blade loading, and angle of incidence and parasitic losses due to windage and blade-housing leakage. The model has been added as a component to the G-PASS plant systems code. The model was developed to support the analysis of S-CO{sub 2} cycles in conjunction with small-scale loop experiments. Such loops operate at less than a MWt thermal input. Their size permits components to be reconfigured in new arrangements relatively easily and economically. However, the small thermal input combined with the properties of carbon dioxide lead to turbomachines with impeller diameters of only one to two inches. At these sizes the dominant phenomena differ from those in larger more typical machines. There is almost no treatment in the literature of turbomachines at these sizes. The present work therefore is aimed at developing turbomachine models that support the task of S-CO{sub 2} cycle analysis using small-scale tests. Model predictions were compared against data from an experiment performed for Sandia National Laboratories in the split-flow Brayton cycle loop currently located at Barber-Nichols Inc. The split-flow loop incorporates two turbo-alternator-compressor (TAC) units each incorporating a radial inflow turbine and a radial flow compressor on a common shaft. The predicted thermodynamic conditions at the outlet of the turbine on the main compressor shaft were compared with measured values at different shaft speeds. Two modifications to the original model were needed to better match the experiment data. First, a representation of the heat loss from the volute downstream of the sensed inlet temperature was added. Second, an empirical multiplicative factor was applied to the Euler head and another to the head loss to bring the predicted outlet pressure into better agreement with the experiment. These changes also brought the overall efficiency of the turbine into agreement with values cited by Barber Nichols for small turbines. More generally, the quality of measurement set data can in the future be improved by additional steps taken in the design and operation of the experimental apparatus. First, a thermocouple mounted at the nozzle inlet would provide a better indication of temperature at this key point. Second, heat losses from the turbine should be measured directly. Allowing the impeller to free wheel at inlet conditions and measuring the temperature drop between inlet and outlet would provide a more accurate measure of heat loss. Finally, the enthalpy change during operation is more accurately obtained by measuring the torque on the stator using strain gauges rather than by measuring pressure and temperature at inlet and outlet to infer thermodynamic states.

Vilim, R. B. (Nuclear Engineering Division)

2012-07-31T23:59:59.000Z

359

Technical Assistance | Department of Energy  

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

Technical Assistance Technical Assistance Technical Assistance The DOE Office of Indian Energy and the Office of Energy Efficiency and Renewable Energy Tribal Energy Program provide federally recognized Indian Tribes, bands, nations, tribal energy resource development organizations, and other organized groups and communities-including Alaska Native villages or regional and village corporations-with technical assistance designed to advance renewable energy and energy efficiency projects. Technical assistance is typically limited to 40 hours and may include, but is not limited to, the following priority areas: Strategic energy planning Grantee support Transmission/interconnection Project development Finance Lease agreements DOE's National Renewable Energy Laboratory and Sandia National

360

Technical Assistance | Department of Energy  

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

Technical Assistance Technical Assistance Technical Assistance The Technical Assistance program is managed through the Center for Sustainable Soil and Groundwater Solutions at SRNL. The Technical Assistance program provides teams of nationally recognized experts from across the complex to support both DOE's smaller sites, such as Paducah, Portsmouth, Pinellas, Ashtabula, Fernald, Mound and Kansas City Plant, and larger sites such as Oak Ridge, Los Alamos, Lawrence Livermore and Savannah River. Solutions that reduce technical risk and uncertainty Focus on science and engineering issues and strategic implementation of remedial systems Independent reviews facilitate regulatory and stakeholder acceptance of solutions. Contacts Karen Skubal karen.skubal@em.doe.gov (301) 903-6524 Justin Marble

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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

Low energy ion beam assisted deposition of a spin valve  

Science Conference Proceedings (OSTI)

The spin dependent electron transport in giant magnetoresistive (GMR) multilayers is significantly affected by the atomic scale structure of their interfaces. Devices with atomically flat and chemically sharp interfaces are preferred for magnetic sensor and memory applications. Recent atomic simulations of the atom-by-atom assembly of these devices indicate that near optimal interfacial structures can be created using low energy, ion assisted vapor deposition techniques with ion energies in the 5-10 eV range. A recently developed biased target ion beam deposition system has been used to experimentally test this hypothesis. Prototypical Ta/NiFe/Co/Cu/Co/FeMn/Cu spin valve structures were first grown using (simultaneous) argon ion assistance during deposition of the Co/Cu/Co trilayer part of the spin valve multilayer. Assisting ion energies of around 10 eV resulted in structures with a 30% higher magnetoresistance ratio and significantly reduced coupling field compared to samples grown with no ion assistance or with ion energies above 15 eV. These results are consistent with the atomistic simulation predictions. Other promising ion assistance schemes identified by the simulations were then used to deposit the Ta, NiFe, FeMn, and the top copper layer. A near optimal strategy was identified that resulted in the further improvement of the GMR ratio.

Quan, J. J.; Wolf, S. A.; Wadley, H. N. G. [Department of Materials Science and Engineering, School of Engineering and Applied Science, University of Virginia, Charlottesville, Virginia 22903 (United States)

2007-04-01T23:59:59.000Z

362

Weatherization and Intergovernmental Program: Technical Assistance  

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

Technical Assistance Technical Assistance Site Map Printable Version Share this resource Send a link to Weatherization and Intergovernmental Program: Technical Assistance to someone by E-mail Share Weatherization and Intergovernmental Program: Technical Assistance on Facebook Tweet about Weatherization and Intergovernmental Program: Technical Assistance on Twitter Bookmark Weatherization and Intergovernmental Program: Technical Assistance on Google Bookmark Weatherization and Intergovernmental Program: Technical Assistance on Delicious Rank Weatherization and Intergovernmental Program: Technical Assistance on Digg Find More places to share Weatherization and Intergovernmental Program: Technical Assistance on AddThis.com... Quick Links Solution Center Weatherization Assistance Program Technical Assistance Center

363

Simulations of the Neutral-beam-induced Rotation, Radial Electric Field, and Flow Shearing Rate in Next-step Burning Plasmas  

SciTech Connect

Toroidal rotation of plasmas in present tokamaks is beneficial for increasing the stability to wall-induced MHD and appears to reduce the anomalous transport associated with micro-turbulence. This paper calculates the toroidal rotation expected from neutral-beam injection in the proposed FIRE and ITER-FEAT tokamak reactors. Self-consistent burning plasmas for these tokamaks have been constructed using the TRANSP plasma analysis code. Neutral-beam injection has been proposed for FIRE and ITER-FEAT. The neutral-beam-induced torques are computed, and assumptions for the anomalous transport of toroidal angular momentum are used to calculate the toroidal rotation profiles. The central Mach numbers are about 3-8%. The ratio of the rotation speed to the Alfvin speed is less than 1%. Assuming neoclassical poloidal rotation and force balance, the radial electric field and flow shearing rate are calculated. Peak shearing rates near the outboard edge are in the 10-100 krad/s range.

R.V. Budny

2002-08-13T23:59:59.000Z

364

Security Assistance | Department of Energy  

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

Security Assistance Security Assistance Security Assistance Welcome to Security Assistance Samuel N. Callahan, Director Mission and Functions The Office of Health, Safety, and Security (HSS) created the Office of Security Assistance Program to provide timely technical assistance and system support to field and Headquarters elements to enhance site security programs, upon request. The program is comprised of technologists and subject matter experts from all security disciplines including Program Management, Protection Program Operations, Information Security, Materials Control and Accountability, and Personnel Security. HSS is committed to building a security assistance program to serve the interests of the Department based upon the needs of our customers - with emphasis on customer-focus and meeting multi-disciplinary security needs. In Fiscal

365

Available Technologies:EnergyPlus: Energy Simulation Software ...  

EnergyPlus is a building energy simulation program for modeling building heating, cooling, lighting, ventilating, and other energy flows

366

NREL: Technology Transfer - Commercialization Assistance Program  

National Renewable Energy Laboratory Technology Transfer Commercialization Assistance Program. The NREL Commercialization Assistance Program (NCAP) helps emerging ...

367

Weatherization Assistance Program: Spurring Innovation, Increasing...  

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

Weatherization Assistance Program: Spurring Innovation, Increasing Home Energy Efficiency Weatherization Assistance Program: Spurring Innovation, Increasing Home Energy Efficiency...

368

Expert assistants for design  

Science Conference Proceedings (OSTI)

Two expert programs currently under development at the Los Alamos National Laboratory, PROCON and the Designer's Apprentice, are briefly described. Both codes define interface to simulations that provide a wide variety of information about the performance of complex devices. (BCS)

Aldridge, J.; Cerutti, J.; Draisin, W.; Steuerwalt, M.

1986-01-01T23:59:59.000Z

369

Development of A Microwave Assisted Particulate Filter Regeneration System  

DOE Green Energy (OSTI)

The need for active regeneration of diesel particulate filters and the advantages of microwave assisted regeneration are discussed. The current study has multiple objectives, which include developing a microwave assisted particulate filter regeneration system for future generation light-duty diesel applications, including PNGV type applications. A variable power 2.0 kW microwave system and a tuned waveguide were employed. Cavity geometry is being optimized with the aid of computational modeling and temperature measurements during microwave heating. A wall-flow ceramic-fiber filter with superior thermal shock resistance, high filtration efficiency, and high soot capacity was used. The microwave assisted particulate filter regeneration system has operated for more than 100 hours in an engine test-cell with a 5.9-liter diesel engine with automated split exhaust flow and by-pass flow capabilities. Filter regeneration was demonstrated using soot loads up to 10 g/liter and engine exhaust at idling flow rates as the oxygen source. A parametric study to determine the optimal combination of soot loading, oxidant flow rate, microwave power and heating time is underway. Preliminary experimental results are reported.

Popuri, Sriram

2001-08-05T23:59:59.000Z

370

An Assistant Interface to Design and Produce a Pop-Up Card  

Science Conference Proceedings (OSTI)

This article describes an assistant interface to design and produce pop-up cards. A pop-up card is a piece of folded paper from which a three-dimensional structure pops up when opened. The authors propose an interface to assist the user in the design ... Keywords: 3-D Graphics, Computer Graphics, Geometric Simulation, Graphical User Interface, Modeling

Sosuke Okamura; Takeo Igarashi

2010-07-01T23:59:59.000Z

371

Reserve's Deputy Assistant Secretary  

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

5, First Quarter, 2012 5, First Quarter, 2012 www.fossil.energy.gov/news/energytoday.html HigHligHts inside 2 Energy Security for the Nation A Column from the Strategic Petroleum Reserve's Deputy Assistant Secretary 3 SPR Completes Drawdown An Inside Look at the Strategic Petroleum Reserve's Operations 6 International Efforts in Clean Energy Fossil Energy Staff Participate in International Organizations to Share Energy Efforts 7 Methane Hydrate Technology Tested International Efforts to Test Technologies in Alaska's North Slope 8 Secretary of Energy Achievement Awards Two NETL Teams Recognized for Significant Environmental Efforts Researchers at the National Energy Technology Laboratory (NETL) are em- ploying conventional technology normally associated with medical proce-

372

Environmental Policy and Assistance  

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

Environmental Protection, Sustainability Support & Corporate Safety Analysis HS-20 Home Mission & Functions » Office of Nuclear Safety, Quality Assurance & Environment » Sustainability Support » Environmental Policy & Assistance » Corporate Safety Programs » Analysis Program Contacts What's New? Sustainability Support Environment Corporate Safety Programs Analysis Environment Environmental Policy Environmental Guidance Environmental Reports Environmental Management System Radiation Protection Environmental Compliance Environmental Justice Environmental Training Environmental Tools Search Our Documents Topics & Resources Air Analytical Services Program CERCLA Cultural & Natural Resources DOE Comments on Rulemakings Federal Environmental Laws

373

Employee Assistance Program  

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

Resources Resources AAP/ EEO Working at LBNL Benefits Lab Information International Researchers & Scholars Office Visitors and Affiliates Contact Us forward Berkeley Lab Staff/ Guests Only forward HR Staff Only forward HR A-Z Benefits at Berkeley Lab Search the HR website: Search UC At Your Service My Accounts image (At Your Service Web Site) UPAY 850 Benefits Change form Benefits Forms and Publications Benefits Orientations Benefit Plan Contacts Calendar of Events: July | August COBRA Information Disability Leave of Absence/FMLA Employee Assistance Programs Employee Self Service Family Member Eligibility Verification UC Retirement Savings Program (Fidelity) Health Care Facilitator Program Employee Discounts and Programs Making Benefit Changes Payroll Information Postdoc Benefits

374

Transportation Economic Assistance Program (Wisconsin)  

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

The Transportation Economic Assistance Program provides state grants to private business and local governments to improve transportation to projects improving economic conditions and creating or...

375

New Mexico Small Business Assistance  

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

Business Assistance Program (NMSBA) helps small businesses in New Mexico access cutting-edge technologies, solve technical issues, and gain knowledge from technical experts at Los...

376

A viscosity counteracting approach in the lattice Boltzmann BGK model for low viscosity flow: Preliminary verification  

Science Conference Proceedings (OSTI)

Due to numerical instability, the lattice Boltzmann model (LBM) with the Bhatnagar-Gross-Krook (BGK) collision operator has some limitations in the simulation of low viscosity flows. In this paper, we propose a viscosity counteracting approach for simulating ... Keywords: Couette flow, Lattice Boltzmann BGK model, Lid-driven cavity flow, Poiseuille flow, Taylor-Green vortex flow, Verification, Viscosity counteracting

Yongguang Cheng; Hui Zhang

2011-06-01T23:59:59.000Z

377

Advanced wellbore thermal simulator GEOTEMP2 research report  

DOE Green Energy (OSTI)

The development of the GEOTEMP2 wellbore thermal simulator is described. The major technical features include a general purpose air and mist drilling simulator and a two-phase steam flow simulator that can model either injection or production.

Mitchell, R.F.

1982-02-01T23:59:59.000Z

378

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

E-Print Network (OSTI)

governing fluid flow through fractured porous media consistSIMULATION OF FLUID FLOW IN FRACTURED POROUS MEDIA T . N .ABSTRACT Fluid flow in fractured porous media can be

Witherspoon, P.A.

2010-01-01T23:59:59.000Z

379

Knowledge Assisted Visualization Knowledge-assisted visualization of seismic data  

E-Print Network (OSTI)

exploration. We describe the existing procedure for oil and gas search which consists of manually extracting for knowledge-assisted annotation and computer-assisted interpretation of seismic data for oil and gas. Introduction Whether we like it or not the world is dependent on energy. Oil and gas accounts for around 64

380

Laser Assisted Emittance Exchange  

Science Conference Proceedings (OSTI)

We describe here the laser assisted emittance exchange (LAEE) technique. A laser operating in the transverse mode (TEM10 or TEM01) is used to interact with the electron beam in a dispersive region and to initiate the transverse-to-longitudinal emittance exchange. It is shown that with the LAEE one can generate an electron beam with ultralow transverse emittance, which allows one to significantly bring down the size of an X-ray free electron laser (FEL) and greatly extend the availability of these light sources. The technique can also be used to enhance the performances of X-ray FELs in storage rings. The timing and energy jitter problems for the standard emittance exchange and LAEE techniques are also discussed.

Xiang, Dao; /SLAC

2012-06-11T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Nursing Simulation: A Review of the Past 40 Years  

Science Conference Proceedings (OSTI)

Simulation, in its many forms, has been a part of nursing education and practice for many years. The use of games, computer-assisted instruction, standardized patients, virtual reality, and low-fidelity to high-fidelity mannequins have appeared in the ... Keywords: anatomical models, computer-assisted instruction, health care education, high-fidelity patient simulation, low-fidelity patient simulation, nursing education, nursing practice, nursing research, objective structured clinical experience, partial task trainers, standardized patients, virtual reality

Wendy M. Nehring; Felissa R. Lashley

2009-08-01T23:59:59.000Z

382

Weatherization and Intergovernmental Program: Weatherization Assistance  

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

Weatherization Assistance Program to someone by E-mail Weatherization Assistance Program to someone by E-mail Share Weatherization and Intergovernmental Program: Weatherization Assistance Program on Facebook Tweet about Weatherization and Intergovernmental Program: Weatherization Assistance Program on Twitter Bookmark Weatherization and Intergovernmental Program: Weatherization Assistance Program on Google Bookmark Weatherization and Intergovernmental Program: Weatherization Assistance Program on Delicious Rank Weatherization and Intergovernmental Program: Weatherization Assistance Program on Digg Find More places to share Weatherization and Intergovernmental Program: Weatherization Assistance Program on AddThis.com... Plans, Implementation, & Results Weatherization Assistance Program Weatherization Services

383

A Bicycle Electric Assist Unit  

E-Print Network (OSTI)

The BEAU is an electric-assist bicycle system that is completely self-contained within the rear wheel. The purpose of approaching a electric-assist bicycle in this manner is two-fold: simplifying the device and opening the ...

Petron, Arthur J

2010-01-01T23:59:59.000Z

384

Simulation of geothermal subsidence  

DOE Green Energy (OSTI)

The results of an assessment of existing mathematical models for subsidence simulation and prediction are summarized. The following subjects are discussed: the prediction process, physical processes of geothermal subsidence, computational models for reservoir flow, computational models for deformation, proficiency assessment, and real and idealized case studies. (MHR)

Miller, I.; Dershowitz, W.; Jones, K.; Myer, L.; Roman, K.; Schauer, M.

1980-03-01T23:59:59.000Z

385

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

386

Contacts for the Assistant General Counsel for Procurement and Financial Assistance  

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

Joseph A. Lenhard, Assistant General Counsel for Procurement & Financial Assistance 202-586-0321 joseph.lenhard@hq.doe.gov

387

Submarine landslide flows simulation through centrifuge modelling  

E-Print Network (OSTI)

2012 “Do not go where the path may lead, go instead where there is no path and leave a trail” - Ralph Waldo Emerson “If I have seen further than others, it is by standing upon the shoulders of giants” - Isaac Newton... . Chang Shin GUE January 2012 iv TABLE OF CONTENTS ABSTRACT ...................................................................................................................i   ACKNOWLEDGMENTS...

Gue, Chang Shin

2012-05-08T23:59:59.000Z

388

Simulations of magnetorheological suspensions in Poiseuille flow  

Science Conference Proceedings (OSTI)

fluid composed of silica gel particles in paraffin oil, in- side a rectangular ... sphere i at the origin of a spherical coordinate system due to sphere j, located at (

389

Fluid Flow and Solidification Simulation of Plutonium  

Science Conference Proceedings (OSTI)

Unalloyed plutonium, which passes through six solid-solid phase transitions as it cools ... Additional complications are the expansion of molten plutonium upon ...

390

Daytime Boundary Layer Evolution over Mountainous Terrain. Part II: Numerical Studies of Upslope Flow Duration  

Science Conference Proceedings (OSTI)

Numerical simulators of upslope flow forming on the lee side of a heated mountain ridge showed this flow to be a transient phenomenon, in agreement with observations. The simulations, performed with a two-dimensional, dry version of the cloud ...

Robert M. Banta

1986-06-01T23:59:59.000Z

391

Job Training Assistance Programs (Tennessee) | Department of...  

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

Sites Power Marketing Administration Other Agencies You are here Home Savings Job Training Assistance Programs (Tennessee) Job Training Assistance Programs (Tennessee)...

392

Energy Efficiency (Policy Assistance) | Department of Energy  

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

Energy Efficiency (Policy Assistance) Energy Efficiency (Policy Assistance) INTRODUCTION The Office of Electricity Delivery and Energy Reliability (OE) is committed to helping...

393

Employee Assistance Program | Brookhaven National Laboratory  

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

Employee Assistance Program Brookhaven's Employee Assistance Program (EAP) is a free confidential service available to help all BNL employees and their family members solve...

394

Renewable Energy Project Assistance | Department of Energy  

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

Technologies Renewable Energy Renewable Energy Project Assistance Renewable Energy Project Assistance October 7, 2013 - 9:41am Addthis The Federal Energy Management Program...

395

Renewable Energy Project Assistance | Department of Energy  

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

Project Assistance Renewable Energy Project Assistance October 7, 2013 - 9:41am Addthis The Federal Energy Management Program (FEMP) provides ongoing renewable energy project...

396

Employee Assistance Self-ID Form  

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

Request for Assistance During an Emergency Employee Self Identification This form is to be used by persons who expect that they will need assistance during an emergency. The...

397

Hydrogen-assisted catalytic ignition characteristics of different fuels  

SciTech Connect

Hydrogen-assisted catalytic ignition characteristics of methane (CH{sub 4}), n-butane (n-C{sub 4}H{sub 10}) and dimethyl ether (DME) were studied experimentally in a Pt-coated monolith catalytic reactor. It is concluded that DME has the lowest catalytic ignition temperature and the least required H{sub 2} flow, while CH{sub 4} has the highest catalytic ignition temperature and the highest required H{sub 2} flow among the three fuels. (author)

Zhong, Bei-Jing; Yang, Fan [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); Yang, Qing-Tao [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China); China Aerodynamics Research and Development Center, Mianyang 621000 (China)

2010-10-15T23:59:59.000Z

398

Performance characteristics of gravity-assisted, potassium heat pipes  

SciTech Connect

Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated and problems with surface wetting are discussed. A comparison between entrainment limits for smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.

Prenger, F.C.; Keddy, E.S.; Sena, J.T.

1985-01-01T23:59:59.000Z

399

UZ Flow Models and Submodels  

SciTech Connect

The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

Y. Wu

2004-11-01T23:59:59.000Z

400

THE DETONATION MECHANISM OF THE PULSATIONALLY ASSISTED GRAVITATIONALLY CONFINED DETONATION MODEL OF Type Ia SUPERNOVAE  

Science Conference Proceedings (OSTI)

We describe the detonation mechanism composing the 'pulsationally assisted' gravitationally confined detonation (GCD) model of Type Ia supernovae. This model is analogous to the previous GCD model reported in Jordan et al.; however, the chosen initial conditions produce a substantively different detonation mechanism, resulting from a larger energy release during the deflagration phase. The resulting final kinetic energy and {sup 56}Ni yields conform better to observational values than is the case for the 'classical' GCD models. In the present class of models, the ignition of a deflagration phase leads to a rising, burning plume of ash. The ash breaks out of the surface of the white dwarf, flows laterally around the star, and converges on the collision region at the antipodal point from where it broke out. The amount of energy released during the deflagration phase is enough to cause the star to rapidly expand, so that when the ash reaches the antipodal point, the surface density is too low to initiate a detonation. Instead, as the ash flows into the collision region (while mixing with surface fuel), the star reaches its maximally expanded state and then contracts. The stellar contraction acts to increase the density of the star, including the density in the collision region. This both raises the temperature and density of the fuel-ash mixture in the collision region and ultimately leads to thermodynamic conditions that are necessary for the Zel'dovich gradient mechanism to produce a detonation. We demonstrate feasibility of this scenario with three three-dimensional (3D), full star simulations of this model using the FLASH code. We characterized the simulations by the energy released during the deflagration phase, which ranged from 38% to 78% of the white dwarf's binding energy. We show that the necessary conditions for detonation are achieved in all three of the models.

Jordan, G. C. IV; Graziani, C.; Weide, K.; Norris, J.; Hudson, R.; Lamb, D. Q. [Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States); Fisher, R. T. [Department of Physics, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02740 (United States); Townsley, D. M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Meakin, C. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Reid, L. B. [NTEC Environmental Technology, Subiaco WA 6008 (Australia)

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Onset Mechanism of Strain-Rate-Induced Flow Stress Upturn  

E-Print Network (OSTI)

The strain-rate response of flow stress in a plastically deforming crystal is formulated through a stress-sensitive dislocation mobility model that can be evaluated by atomistic simulation. For the flow stress of a model ...

Fan, Yue

402

Collision Rates of Cloud Droplets in Turbulent Flow  

Science Conference Proceedings (OSTI)

Direct numerical simulations of an evolving turbulent flow field have been performed to explore how turbulence affects the motion and collisions of cloud droplets. Large numbers of droplets are tracked through the flow field and their positions, ...

Charmaine N. Franklin; Paul A. Vaillancourt; M. K. Yau; Peter Bartello

2005-07-01T23:59:59.000Z

403

Tankathon-A Process Plant Simulation  

E-Print Network (OSTI)

Tankathon is a simulation of a process plant in a computer generated environment. Interaction and control in three dimensional control systems are studied. The simulated "process" consists of seven tanks containing a "liquid" flowing from tanks to tanks. The goal of the "plant manager", the user, is to keep the tanks from draining or overflowing. The user can interact with valves in the pipes connecting the tanks in order to regulate the liquid flow and check the flow rate.

Kai-Mikael Jää-Aro

1992-01-01T23:59:59.000Z

404

Direct numerical simulation of evaporating droplets  

Science Conference Proceedings (OSTI)

A model for the three-dimensional direct numerical simulation of evaporating, deforming droplets in incompressible flow is presented. It is based on the volume-of-fluid method and is therefore capable of capturing very strong deformations. The evaporation ... Keywords: DNS, Deformed droplets, Evaporation, Multiphase flow, Stefan flow, VOF

Jan Schlottke; Bernhard Weigand

2008-05-01T23:59:59.000Z

405

Modeling & Simulation  

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

Modeling & Simulation Modeling & Simulation Research into alternative forms of energy, especially energy security, is one of the major national security imperatives of this...

406

A numerical study of flow-structure interactions with application to flow past a pair of cylinders  

E-Print Network (OSTI)

Flow-structure interaction is a generic problem for many engineering applications, such as flow--induced oscillations of marine risers and cables. In this thesis a Direct Numerical Simulation (DNS) approach based on ...

Papaioannou, Georgios (Georgios Vasilios), 1975-

2004-01-01T23:59:59.000Z

407

Modeling and Dynamic Simulation of Electric Power Steering System of Automobile Using Bond Graph Technique  

Science Conference Proceedings (OSTI)

Electric Power Steering (EPS) systems have many merits over traditional hydraulic power steering systems in fuel economy, variable assist capabilities and favorable road feeling by virtue of adjustment assist characteristic with adopting assist motor ... Keywords: electric power steering system, bond graph, modeling, simulation

Lin-an Wang; Qiang Li; Xiao-juan Liang

2010-04-01T23:59:59.000Z

408

Stress-Assisted Corrosion in Boiler Tubes  

Science Conference Proceedings (OSTI)

A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

Preet M Singh; Steven J Pawel

2006-05-27T23:59:59.000Z

409

The MIT Design Advisor : simple and rapid energy simulation of early-stage building designs  

E-Print Network (OSTI)

Simulation tools, when applied early in the design process, can considerably reduce the energy demand of newly constructed buildings. For a simulation tool to assist with design, it must be easy to use, provide feedback ...

Urban, Bryan J. (Bryan James)

2007-01-01T23:59:59.000Z

410

Towards improved methods for determining porous media multiphase flow functions.  

E-Print Network (OSTI)

??The mathematical modeling and simulation of the flow of fluid through porous media are important in many areas. Relative permeability and capillary pressure functions are… (more)

Xue, Song

2004-01-01T23:59:59.000Z

411

Modeling and Simulation of a Solar Assisted Desiccant Cooling...  

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

system comprises a desiccant wheel containing Lithium Chloride in tandem with a rotating heat exchanger and two humidifiers on both supply and return air. The required...

412

An Experimentally Assisted Numerical Simulation of Metal Forming ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Advances in Hydroelectric Turbine Manufacturing and Repair. Presentation ...

413

Orographic Clouds in Terrain-Blocked Flows: An Idealized Modeling Study  

Science Conference Proceedings (OSTI)

Idealized numerical simulations of moist strongly stratified flow over topography are used to study the processes that control orographic clouds in terrain-blocked flows as a joint function of the nondimensional flow parameter Nh/U, the ...

Joseph Galewsky

2008-11-01T23:59:59.000Z

414

Geothermal direct-heat utilization assistance  

DOE Green Energy (OSTI)

Progress on technical assistance, R D activities, technology transfer, and geothermal progress monitoring is summarized.

Not Available

1992-12-01T23:59:59.000Z

415

Stochastic algorithms for the analysis of numerical flame simulations  

Science Conference Proceedings (OSTI)

Recent progress in simulation methodologies and high-performance parallel computers have made it is possible to perform detailed simulations of multidimensional reacting flow phenomena using comprehensive kinetics mechanisms. As simulations become larger ... Keywords: computational diagnostics, particle tracking, reacting flows, stochastic

J. B. Bell; M. S. Day; J. F. Grcar; M. J. Lijewski

2005-01-01T23:59:59.000Z

416

Weatherization Assistance Program | Open Energy Information  

Open Energy Info (EERE)

Weatherization Assistance Program Weatherization Assistance Program Jump to: navigation, search Name Weatherization Assistance Program Place Washington, DC Website http://http://www1.eere.energy References Weatherization Assistance Program[1] Information About Partnership with NREL Partnership with NREL Yes Partnership Type Test & Evaluation Partner Partnering Center within NREL Electricity Resources & Building Systems Integration LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! Weatherization Assistance Program is a company located in Washington, DC. References ↑ "Weatherization Assistance Program" Retrieved from "http://en.openei.org/w/index.php?title=Weatherization_Assistance_Program&oldid=381735" Categories: Clean Energy Organizations

417

Weatherization and Intergovernmental Program: Weatherization Assistance  

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

Weatherization Assistance Program Allocation Formula to someone by E-mail Share Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on Facebook Tweet about Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on Twitter Bookmark Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on Google Bookmark Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on Delicious Rank Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on Digg Find More places to share Weatherization and Intergovernmental Program: Weatherization Assistance Program Allocation Formula on

418

Alternative Fuels Data Center: Project Assistance  

Alternative Fuels and Advanced Vehicles Data Center (EERE)

About About Printable Version Share this resource Send a link to Alternative Fuels Data Center: Project Assistance to someone by E-mail Share Alternative Fuels Data Center: Project Assistance on Facebook Tweet about Alternative Fuels Data Center: Project Assistance on Twitter Bookmark Alternative Fuels Data Center: Project Assistance on Google Bookmark Alternative Fuels Data Center: Project Assistance on Delicious Rank Alternative Fuels Data Center: Project Assistance on Digg Find More places to share Alternative Fuels Data Center: Project Assistance on AddThis.com... More in this section... Project Assistance News & Features Spanish Resources Contacts Project Assistance Through a nationwide network of local coalitions, Clean Cities provides project assistance to help stakeholders in the public and private sectors

419

The simol modeling language for simulation and (re-)configuration  

Science Conference Proceedings (OSTI)

From automotive and up to telecommunication industry, configuration and simulation are used for solving complex problems connected to the ever growing number of components, which have to work together. To assist these needs, many tools are nowadays available. ...

Iulia Nica; Franz Wotawa

2012-01-01T23:59:59.000Z

420

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

Turbulent Turbulent Flow with Implicit LES L.G. Margolin 1 Proceedings of the Joint Russian-American Five Laboratory Conference on Computational Mathematics/Physics 19-23 June, 2005 Vienna, Austria 1 Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, len@lanl.gov 1 Abstract Implicit large eddy simulation (ILES) is a methodology for modeling high Reynolds' num- ber flows that combines computational efficiency and ease of implementation with predictive calculations and flexible application. Although ILES has been used for more than fifteen years, it is only recently that significant effort has gone into providing a physical rationale that speaks to its capabilities and its limitations. In this talk, we will present new theoret- ical results aimed toward building a justification and discuss some remaining gaps in our understanding and our practical

Note: This page contains sample records for the topic "flow simulation assisted" 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

flow_loop.indd  

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

FLOW ASSURANCE TEST LOOP FLOW ASSURANCE TEST LOOP Objective O ver a decade ago, RMOTC began cooperatively building a full-scale facility to test new fl ow assurance technology, mainly in the areas of hydrates and paraffi ns. Today, RMOTC's test facility consists of fi ve individual loop sections, including chilling and heated pipe-in-pipe water sections, bare lines, and a mixing section. The facility was designed to represent typical deepwater production systems in order to simulate full-scale tests and apply the results to fl ow assurance fi eld applications and technology. The current facility design consists of a 6" x 3,600 maximum allowable operating pressure test pipeline in fi ve separate loops. The test loops begin and ter- minate at a central location just north

422

Implicit Large Eddy Simulation  

National Nuclear Security Administration (NNSA)

Implicit Implicit Large Eddy Simulation (ILES) for High Reynolds Number Flows Len Margolin Applied Physics Division Los Alamos National Laboratory Collaborators: 1. Bill Rider (LANL) 2. Piotr Smolarkiewicz (NCAR) 3. Andrzej Wysogrodski (NCAR) 4. Fernando Grinstein (NRL) len@lanl.gov 1 Implicit Large Eddy Simulation Outline: * What is ILES? * What are its advantages? * Historical perspective * Why does it work? * Some examples len@lanl.gov 2 What is ILES ILES is the direct application of a fluid solver to a high Reynolds number fluid flow with no explicit turbulence model. · The truncation terms of the algorithm serve as an effective model of the effects of the unresolved scales. · Fluid solvers based on Nonoscillatory Finite Volume (NFV) approximations work effectively for ILES. · Fluid solvers based on pseudospectral methods, leapfrog methods, advective form methods, etc. do not work

423

Community Assistance | Department of Energy  

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

Community Assistance Community Assistance Community Assistance For more than 50 years, DOE and its predecessor agencies produced materials to manufacture nuclear weapons and conduct activities for the Manhattan Engineer District. To accommodate these activities, more than 20,000 facilities throughout the country were built, a large contractor work force was established, and communities were transformed. President George H.W. Bush's announcement of the first unilateral nuclear weapons reduction agreement on September 27, 1991, signaled the end of the Cold War and dramatically reduced the need for further nuclear weapons production. DOE is committed to alleviating the negative impact of its changing mission on its contractor work force, who were instrumental in accomplishing

424

Fluid Flow Within Fractured Porous Media  

Science Conference Proceedings (OSTI)

Fractures provide preferential flow paths to subterranean fluid flows. In reservoir scale modeling of geologic flows fractures must be approximated by fairly simple formulations. Often this is accomplished by assuming fractures are parallel plates subjected to an applied pressure gradient. This is known as the cubic law. An induced fracture in Berea sandstone has been digitized to perform numerical flow simulations. A commercially available computational fluid dynamics software package has been used to solve the flow through this model. Single phase flows have been compared to experimental works in the literature to evaluate the accuracy with which this model can be applied. Common methods of fracture geometry classification are also calculated and compared to experimentally obtained values. Flow through regions of the fracture where the upper and lower fracture walls meet (zero aperture) are shown to induce a strong channeling effect on the flow. This model is expanded to include a domain of surrounding porous media through which the flow can travel. The inclusion of a realistic permeability in this media shows that the regions of small and zero apertures contribute to the greatest pressure losses over the fracture length and flow through the porous media is most prevalent in these regions. The flow through the fracture is shown to be the largest contributor to the net flow through the media. From this work, a novel flow relationship is proposed for flow through fractured media.

Crandall, D.M.; Ahmadi, G. (Clarkson Univ., Potsdam, NY); Smith, D.H.; Bromhal, G.S.

2006-10-01T23:59:59.000Z

425

FLOW GATING  

DOE Patents (OSTI)

BS>This invention is a fast gating system for eiectronic flipflop circuits. Diodes connect the output of one circuit to the input of another, and the voltage supply for the receiving flip-flop has two alternate levels. When the supply is at its upper level, no current can flow through the diodes, but when the supply is at its lower level, current can flow to set the receiving flip- flop to the same state as that of the circuit to which it is connected. (AEC)

Poppelbaum, W.J.

1962-12-01T23:59:59.000Z

426

Thomas D. Williams Assistant Administrator  

Gasoline and Diesel Fuel Update (EIA)

Thomas D. Williams Thomas D. Williams Assistant Administrator for Resource and Tecnology Management Duties Thomas D. Williams is the Assistant Administrator for Resource & Technology Management. He provides leadership and direction to oversee the management and operation of EIA's employee services, information technology policy and operations, and integrated planning, budget, procurement, evaluation and project management activity. Biography Thom is a career member of the Senior Executive Service with more than 27 years of professional experience in developing, linking, and implementing successful strategic, financial, human capital, operational, technology, and administrative policies and plans for federal research, science, engineering, and regulatory programs.

427

Medical Assisting Medical Assistants perform routine administrative and clinical tasks to keep the offices of physi-  

E-Print Network (OSTI)

Medical Assisting Medical Assistants perform routine administrative and clinical tasks to keep. Medical assis- patients for x-rays, take electrocardiograms, remove sutures, and change dressings. Medical Description: Medical Assisting Associate of Applied Science (4 semesters after prerequisites are complet

Crone, Elizabeth

428

Comparison of engine simulation software for development of control system  

Science Conference Proceedings (OSTI)

Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine ...

KinYip Chan, Andrzej Ordys, Konstantin Volkov, Olga Duran

2013-01-01T23:59:59.000Z

429

LEDSGP/assistance | Open Energy Information  

Open Energy Info (EERE)

assistance assistance < LEDSGP Jump to: navigation, search LEDSGP Logo.png Advancing climate-resilient low emission development around the world Home About Tools Expert Assistance Events Publications Join Us Expert Assistance Finance Transport Meet the Experts Assistance Provided Expert Assistance on LEDS We provide no-cost expert assistance on LEDS-related finance and waste, and we will soon be providing no-cost expert assistance on transport and analysis activities. In addition, our partners at the Clean Energy Solutions Center, provide no-cost clean energy policy assistance. Powered by OpenEI ledsgp.org is built on the same platform as the popular Wikipedia site. Like Wikipedia, it is a "wiki" or website developed collaboratively by a community of users. Thanks to our unique relationship with OpenEI.org, you

430

Network Simulation  

SciTech Connect

A detailed introduction to the design, implementation and use of network simulation tools is presented. The requirements and issues faced in the design of simulators for wired and wireless networks are discussed. Abstractions such as packet- and fluid-level network models are covered. Several existing simulations are given as examples, with details and rationales regarding design decisions presented. Issues regarding performance and scalability are discussed in detail, describing how one can utilize distributed simulation methods to increase the scale and performance of a simulation environment. Finally, a case study of two simulation tools is presented that have been developed using distributed simulation techniques. This text is essential to any student, researcher or network architect desiring a detailed understanding of how network simulation tools are designed, implemented, and used.

Fujimoto, Richard [ORNL; Perumalla, Kalyan S [ORNL; Riley, George F. [Georgia Institute of Technology

2006-01-01T23:59:59.000Z

431

Flow cytometer  

DOE Patents (OSTI)

A Faraday cage enclosing the flow chamber of a cytometer and ground planes associated with each field deflection plate in concert therewith inhibit electric fields from varying the charge on designated events/droplets and further concentrates and increases forces applied to a charged event passing therethrough for accurate focus thereof while concomitantly inhibiting a potential shock hazard.

van den Engh, Ger (Seattle, WA)

1995-01-01T23:59:59.000Z

432

Flow cytometer  

DOE Patents (OSTI)

A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.

Van den Engh, G.

1995-11-07T23:59:59.000Z

433

Radiological Assistance Program | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Assistance Program | National Nuclear Security Administration Assistance Program | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Radiological Assistance Program Home > About Us > Our Programs > Emergency Response > Responding to Emergencies > First Responders > Radiological Assistance Program Radiological Assistance Program RAP Logo NNSA's Radiological Assistance Program (RAP) is the nation's

434

Office of Enforcement - Regulatory Assistance Reviews  

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

Regulatory Assistance Reviews Regulatory Assistance Reviews Office of Enforcement and Oversight (formerly Program Reviews) Enforcement Regulatory Assistance Reviews evaluate contractor programs for identifying, evaluating, reporting and correcting noncompliances. The objective of these reviews is to work collaboratively with sites to identify areas where program effectiveness can be improved and ensure that noncompliances are being proactively self-identified. 2013 Office of Security Enforcement Regulatory Assistance Review of Battelle at the Pacific Northwest National Laboratory, July 18, 2013 Office of Worker Safety and Health Enforcement Regulatory Assistance Review of L ATA Environmental Services of Kentucky, LLC at the Paducah Gaseous Diffusion Plant, February 11, 2013 Office of Security Enforcement Regulatory Assistance Review of

435

Radiological Assistance Program | National Nuclear Security Administration  

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

Assistance Program | National Nuclear Security Administration Assistance Program | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Radiological Assistance Program Home > About Us > Our Programs > Emergency Response > Responding to Emergencies > First Responders > Radiological Assistance Program Radiological Assistance Program RAP Logo NNSA's Radiological Assistance Program (RAP) is the nation's

436

STABLE HEATING OF CLUSTER COOLING FLOWS BY COSMIC-RAY STREAMING  

SciTech Connect

We study heating of cool cores in galaxy clusters by cosmic-ray (CR) streaming using numerical simulations. In this model, CRs are injected by the central active galactic nucleus (AGN) and move outward with Alfven waves. The waves are excited by the streaming itself and become nonlinear. If magnetic fields are large enough, CRs can prevail in and heat the entire core because of a large Alfven velocity. We find that the CR streaming can stably heat both high- and low-temperature clusters for a long time without the assistance of thermal conduction, and it can prevent the development of massive cooling flows. If there is even a minor contribution from thermal conduction, the heating can be stabilized further. We discuss the reason for the stability and indicate that the CR pressure is insensitive to changes in the intracluster medium (ICM) and that the density dependence of the heating term is similar to that of radiative cooling.

Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Ohira, Yutaka, E-mail: fujita@vega.ess.sci.osaka-u.ac.jp [Theory Centre, Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan)

2011-09-10T23:59:59.000Z

437

Combined Phase Field – Lattice Boltzmann Simulation of Dendritic ...  

Science Conference Proceedings (OSTI)

Presentation Title, Combined Phase Field – Lattice Boltzmann Simulation of Dendritic Solidification with Fluid Flow and Solid Particle Motion. Author(s), Dmitry ...

438

EnergyPlus: Energy Simulation Software for Buildings - Energy ...  

EnergyPlus is a building energy simulation program for modeling building heating, cooling, lighting, ventilating, and other energy flows. While it is based on the ...

439

Lattice splitting under intermittent flows  

E-Print Network (OSTI)

We study the splitting of regular square lattices subject to stochastic intermittent flows. By extensive Monte Carlo simulations we reveal how the time span until the occurence of a splitting depends on various flow patterns imposed on the lattices. Increasing the flow fluctuation frequencies shortens this time span which reaches a minimum before rising again due to inertia effects incorporated in the model. The size of the largest connected component after the splitting is rather independent of the flow fluctuations but sligthly decreases with the link capacities. Our results are relevant for assessing the robustness of real-life systems, such as electric power grids with a large share of renewable energy sources including wind turbines and photovoltaic systems.

Schläpfer, Markus

2010-01-01T23:59:59.000Z

440

Resolution Requirements for the Simulation of Deep Moist Convection  

Science Conference Proceedings (OSTI)

The spatial resolution appropriate for the simulation of deep moist convection is addressed from a turbulence perspective. To provide a clear theoretical framework for the problem, techniques for simulating turbulent flows are reviewed, and the ...

George H. Bryan; John C. Wyngaard; J. Michael Fritsch

2003-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "flow simulation assisted" 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

Loop simulation capability for sodium-cooled systems  

E-Print Network (OSTI)

A one-dimensional loop simulation capability has been implemented in the thermal-hydraulic analysis code, THERMIT-4E. This code had been used to simulate and investigate flow in test sections of experimental sodium loops ...

Adekugbe, Oluwole A.

1984-01-01T23:59:59.000Z

442

Deashing of coal liquids by sonically assisted filtration  

Science Conference Proceedings (OSTI)

This project seeks to improve the effectiveness and reduce the cost of coal liquefaction by novel applications of sonic and ultrasonic energy. The specific purpose of this project is to develop and improve means for the economical removal of dispersed solid particles of ash, unreacted coal, and spent catalyst from direct and indirect coal liquefaction resids by using sonic or ultrasonic waves. Product streams containing solids are generated in both direct and indirect coal liquefaction processes. Direct coal liquefaction processes generate liquid products which contain solids including coal-originated mineral matter, unreacted coal, and spent dispersed catalyst. The removal of these solids from a product stream is one of the most difficult problems in direct coal liquefaction processes. On this report, results are discussed for sonically assisted crossflow filtration of V-1067 resid, diluted with No. 2 fuel oil, and sonically assisted batch filtrations of solids concentrates from continuous cross-flow filtration experiments.

Slomka, B.J.

1994-10-01T23:59:59.000Z

443

DOE Hydrogen Analysis Repository: FLOW Model  

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

FLOW Model FLOW Model Project Summary Full Title: Chemical Engineering Process Simulation Platform - FLOW Project ID: 131 Principal Investigator: Juan Ferrada Brief Description: FLOW is a steady-state chemical process simulator. Modules have been developed for supply chain calculations, micro-economic calculations, and other calculations. Purpose Simulate steady-state chemical processes to support hydrogen infrastructure and transition analysis. Performer Principal Investigator: Juan Ferrada Organization: Oak Ridge National Laboratory (ORNL) Address: Bethel Valley 1, Bldg 5700, N217 Oak Ridge, TN 37831-6166 Telephone: 865-574-4998 Email: ferradajj@ornl.gov Sponsor(s) Name: Fred Joseck Organization: DOE Hydrogen Program Telephone: 202-586-7932 Email: Fred.Joseck@ee.doe.gov

444

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

445

State and Regional Policy Assistance | Department of Energy  

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

Assistance State and Regional Policy Assistance Mission The Office of Electricity Delivery and Energy Reliability (OE)'s mission with State and Regional Policy Assistance is to...

446

Clean Cities: Clean Cities Technical Assistance (Tiger Teams...  

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

Technical Assistance (Tiger Teams) Clean Cities offers technical assistance for eligible projects through the Clean Cities Technical Assistance Project, also known as Tiger Teams....

447

Guide to Financial Assistance | Department of Energy  

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

Guide to Financial Assistance Guide to Financial Assistance Guide to Financial Assistance Guide to Financial Assistance The Guide to Financial Assistance is a reference document that provides a compilation of non-regulatory information and guidance related to the implementation of existing statutory and regulatory requirements. Regulatory requirements are contained in the DOE Financial Assistance Rules, 10 CFR Part 600 and applicable program rules. Each year DOE obligates nearly $2 billion on financial assistance actions in the form of grants and cooperative agreements to states, local and tribal governments, universities, non-profit organizations, for-profit organizations, and individuals. This guidance is intended to help DOE staff carry out its financial assistance activities. Information contained herein is intended to be

448

Contractor Employee Assistance at DOE Contractor Sites  

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

Worker Safety and Health Assistance Worker Safety and Health Assistance Home Mission and Functions Voluntary Protection Program Employee Assistance Program for DOE Contractor and Subcontractor Workers Technical Assistance Rulemaking Human Reliability Program Technical Assistance Rulemaking Health and Safety HSS Logo Contractor Employee Assistance at DOE Contractor Sites Employee Assistance Program For DOE Contractor and Subcontractor Workers The DOE Employee Assistance Program (EAP) for DOE contractor and subcontractor workers complements the DOE medical and psychological evaluations and surveillance program. The EAP provides contractor workers who are experiencing personal problems with an opportunity to receive appropriate treatment and support. The goal of the EAP is to provide a conduit through which the individual can resolve personal and workplace problems. The HSS EAP Manager aids the DOE contracting organizations to maintain a healthy and productive workforce.

449

FEMP Renewable Energy Project Assistance Application  

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

Renewable Energy Project Assistance Application Renewable Energy Project Assistance Application Please complete electronically Request Date: _________________________________________________________________________________________ Federal Agency: _______________________________________________________________________________________ Federal Agency Contact Person Name: ______________________________________________________________________ Phone: ______________________________________________________________________________________________ E-mail: ______________________________________________________________________________________________ Project Name: ________________________________________________________________________________________ Project Location: City _________________________________________ State ___________ Zip Code __________________

450

Guide to Financial Assistance | Department of Energy  

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

Guide to Financial Assistance Guide to Financial Assistance Guide to Financial Assistance Guide to Financial Assistance The Guide to Financial Assistance is a reference document that provides a compilation of non-regulatory information and guidance related to the implementation of existing statutory and regulatory requirements. Regulatory requirements are contained in the DOE Financial Assistance Rules, 10 CFR Part 600 and applicable program rules. Each year DOE obligates nearly $2 billion on financial assistance actions in the form of grants and cooperative agreements to states, local and tribal governments, universities, non-profit organizations, for-profit organizations, and individuals. This guidance is intended to help DOE staff carry out its financial assistance activities. Information contained herein is intended to be

451

An Intelligent Teaching Assistant System for Logic  

Science Conference Proceedings (OSTI)

This paper presents the Logic-ITA, an Intelligent Teaching Assistant system for the teaching/learning of propositional logic. Intelligent Teaching Assistant Systems are dedicated both to learners and teachers. The system embeds three tools: the Logic ...

Leanna Lesta; Kalina Yacef

2002-06-01T23:59:59.000Z

452

Radiation Emergency Assistance Center / Training Site | National...  

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

Radiation Emergency Assistance Center Training Site | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

453

Numerical Simulation of Sudden Stratospheric Warmings  

Science Conference Proceedings (OSTI)

A mechanistic, quasi-geostrophic, semi-spectral model with a self-consistent calculation of the mean zonal flow fields is used to numerically simulate sudden stratospheric warmings generated by a single zonal harmonic (m) planetary wave. The ...

Mark R. Schoeberl; Darrell F. Strobel

1980-01-01T23:59:59.000Z

454

Transportation Analysis, Modeling, and Simulation (TAMS) Application  

E-Print Network (OSTI)

Transportation Analysis, Modeling, and Simulation (TAMS) Application Center for Transportation Passenger Flows Supply Chain Efficiency Transportation: Energy Environment Safety Security Vehicle Technologies T he Center for Transportation Analysis (CTA) TAMS application is a web-based tool that supports

455

Numerical Simulation of Macrosegregation Formation during ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

456

THE DOE GUIDE TO FINANCIAL ASSISTANCE  

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

2.8 Noncompetitive Financial Assistance ................................................................................................................ 46 2.8 Noncompetitive Financial Assistance ................................................................................................................ 46 CHAPTER 3 - AWARD .............................................................................................................................................. 48 3.1 Assistance Agreement form/Terms and Conditions ........................................................................................... 48 3.2 Pre-Award Costs (05/2013) ................................................................................................................................. 49 3.3 Budget and Project Periods (05/2013) ................................................................................................................ 50

457

Evaluation of TANK Water Heater Simulation Model as Embedded in HWSim  

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

TANK Water Heater Simulation Model as Embedded in HWSim TANK Water Heater Simulation Model as Embedded in HWSim Title Evaluation of TANK Water Heater Simulation Model as Embedded in HWSim Publication Type Report LBNL Report Number LBNL-5092E Year of Publication 2010 Authors Lutz, James D. Document Number LBNL-5092E Pagination 11 Date Published December 22 Publisher Lawrence Berkeley National Laboratory City Berkeley ISBN Number LBNL-5092E Abstract This report evaluates the hot water temperatures and flow rates as calculated by the combined HWSim and TANK simulation models. Notes This work was sponsored by the Gas Technology Institute (GTI) which is funded by the California Energy Commission, Public Interest Energy Research (PIER) Program, under Residential Water Heating Program Contract No. 500-08-060. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State, and Community Programs, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

458

Development of an S-Saltcake Simulant Using Crossflow Filtration as a Validation Technique  

SciTech Connect

In the past several years, cross-flow filtration has been studied extensively in a bench-scale system at Pacific Northwest National Laboratory (PNNL) using both actual tank waste from the Hanford site and waste simulants. One challenge when creating a waste simulant is duplicating the filtration behaviour of real waste, in particular when the waste composition is not known with certainty. Using a systematic approach to filtration testing, it has been found that the solid components that dominate the filtration behaviour can be identified. This approach was used to develop a waste simulant for S-Saltcake tank waste. The analysis of filtration data assists in screening solid components when the chemical composition and structure of a metal is not known. This is well-illustrated in this study during the search for the appropriate chromium phase. After the likely components were identified, the solids were combined with a supernate that is representative of the real waste and the filtration performance was verified against real waste data. A secondary benefit of this approach is the construction of a database of filtration performance for various solid species that can be used to quickly develop waste simulants in the future.

Schonewill, Philip P.; Daniel, Richard C.; Russell, Renee L.; Shimskey, Rick W.; Burns, Carolyn A.; Billing, Justin M.; Rapko, Brian M.; Peterson, Reid A.

2012-11-02T23:59:59.000Z

459

Electrically-Assisted Turbocharger Development for Performance and Emissions  

DOE Green Energy (OSTI)

Turbocharger transient lag inherently imposes a tradeoff between a robust engine response to transient load shifts and exhaust emissions. By itself, a well matched turbocharger for an engine has limited flexibility in improving this transient response. Electrically-assisted turbocharging has been seen as an attractive option to improve response and lower transient emissions. This paper presents the results of a multi-year joint CRADA between DDC and ORNL. Virtual lab diesel simulation models characterized the performance improvement potential of an electrically assisted turbocharger technology. Operating requirements to reduce transient duration between load shift time by up to 50% were determined. A turbomachine has been conceptualized with an integrated motor-generator, providing transient burst boost plus energy recovery capability. Numerous electric motor designs were considered, and a prototype motor was developed, fabricated, and is undergoing tests. Power controls have been designed and fabricated.

Bailey, Milton

2000-08-20T23:59:59.000Z

460

DOE and NREL Technical Assistance  

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

NREL provided technical assistance to NREL provided technical assistance to Greensburg, Kansas, in the following areas. MASTER PLAN FOR REBUILDING GREEN * Completed detailed studies on renewable energy sources, cost-effective energy options, and potential integrated energy solutions * Worked with federal, state, and local agencies; city leaders and residents; energy consultants; and others to further the town's vision of becoming an affordable sustainable community. HIGH-PERFORMANCE BUILDINGS * Set aggressive energy efficiency goals for all new homes to use 30%-40% less energy than before the tornado, new city buildings to achieve LEED ® Platinum, and other commercial and public buildings to be designed to LEED Platinum or Gold. COMMUNITY WIND ENERGY * Conducted detailed computer modeling and

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461

New Mexico Small Business Assistance  

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

Business Assistance Program (NMSBA) helps small businesses in New Mexico access cutting-edge technologies, solve technical issues, and gain knowledge from technical experts at Los Alamos and Sandia National Laboratories (SNL). This assistance is provided at no cost to the small businesses. In 2012, the State of New Mexico, along with LANL and SNL, invested $4.5M helping 349 companies in 27 counties solve their technical challenges through NMSBA. Economic Impact of the Small Businesses related to NMSBA Small Business Jobs Created/Retained 2,874 Average Salary $38,647 Increased Revenue $145.2M Decreased Operating Costs $72.6M New Funding/Financing Received $52.3M

462

A multi-feedzone wellbore simulator  

DOE Green Energy (OSTI)

A multi-feedzone wellbore simulator has been developed. This computer code is quite general as it enables one to compute downhole conditions in wells with an arbitrary number of feedzones during discharge or injection. The simulator is applied to flowing pressure and temperature surveys from various wells in Mexico, Iceland and Kenya. It is demonstrated that such a model can be used to estimate flow rates and enthalpies of individual feedzones.

Bjornsson, G.; Bodvarsson, G.S.

1987-06-01T23:59:59.000Z

463

Validation of a Geothermal Simulator  

DOE Green Energy (OSTI)

A geothermal simulator, TETRAD, is validated against the Stanford Geothermal Problem Set. The governing equations, formulation, and solution technique employed by TETRAD are first outlined. Each problem in the Stanford Problem Set is then discussed in detail, and results from the simulations are presented. The results obtained using TETRAD are compared against several other geothermal simulators. Favorable comparison between results indicates that TETRAD is capable of solving the highly non-linear equations describing the flow of mass and energy in porous media. This validation exercise allows for the use of TETRAD in studying geothermal problems with a high degree of confidence.

Shook, G.M.; Faulder, D.D.

1991-10-01T23:59:59.000Z

464

Avestar® - Simulators  

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...

465

Magnetic Amplifier for Power Flow Control  

Science Conference Proceedings (OSTI)

GENI Project: ORNL is developing an electromagnet-based, amplifier-like device that will allow for complete control over the flow of power within the electric grid. To date, complete control of power flow within the grid has been prohibitively expensive. ORNL’s controller could provide a reliable, cost-effective solution to this problem. The team is combining two types of pre-existing technologies to assist in flow control, culminating in a prototype iron-based magnetic amplifier. Ordinarily, such a device would require expensive superconductive wire, but the magnetic iron core of ORNL’s device could serve as a low-cost alternative that is equally adept at regulating power flow.

None

2012-02-24T23:59:59.000Z

466

How to assess the acceptability and credibility of simulation results  

Science Conference Proceedings (OSTI)

The purpose of this paper is to present a comprehensive life cycle of a simulation study and guide the simulationist in conducting 10 processes, 10 phases, and 13 credibility assessment stages of the life cycle. The guidelines assist the simulation practitioners ...

O. Balci

1989-10-01T23:59:59.000Z

467

NFFLOW: A reservoir simulator incorporating explicit fractures (SPE 153890)  

SciTech Connect

NFFLOW is a research code that quickly and inexpensively simulates flow in moderately fractured reservoirs. It explicitly recognizes fractures separately from rock matrix. In NFFLOW fracture flow is proportional to the pressure gradient along the fracture, and flow in the rock matrix is determined by Darcy’s Law. The two flow mechanisms are coupled through the pressure gradient between a fracture and its adjacent rock matrix. Presented is a promising change to NFFLOW that allows for flow across a rock matrix block.

Boyle, E.J.; Sams, W.N.

2012-01-01T23:59:59.000Z

468

Small Business Pollution Prevention Assistance Account Loan Program...  

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

Small Business Pollution Prevention Assistance Account Loan Program Small Business Pollution Prevention Assistance Account Loan Program Eligibility Commercial Industrial Savings...

469

Anaheim Public Utilities - Small Business Energy Management Assistance...  

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

Anaheim Public Utilities - Small Business Energy Management Assistance Program Anaheim Public Utilities - Small Business Energy Management Assistance Program Eligibility Commercial...

470

Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

471

Intelligent interface for design and simulation  

Science Conference Proceedings (OSTI)

We are developing a system composed of intelligent interfaces, expert systems, and databases that uses artificial intelligence techniques to simplify the use of large simulation codes and to help design complicated physical devices. The simulation codes are used in analyzing and designing weapons, and the devices are themselves parts of weapon systems. From a designer's point of view, the simulation process is the same no matter what is being simulated. In the course of developing two intelligent interfaces for the design of nuclear weapons, we have found that data-driven programming is a useful technique for implementing an open-ended user interface to assist the designer. We discuss the simulation process as it is done now and as it could be done with intelligent interfaces. We then discuss the use of data-driven programming in a database environment to support an interface for an arbitrary number of simulation codes. 3 figs.

Draisin, W.; Peter, E.

1986-01-01T23:59:59.000Z

472

Characterization of the Weatherization Assistance Program network. Weatherization Assistance Program  

Science Conference Proceedings (OSTI)

The Characterization of the Weatherization Assistance Program (WAP) Network was designed to describe the national network of State and local agencies that provide WAP services to qualifying low-income households. The objective of this study was to profile the current WAP network. To achieve the objective, two national surveys were conducted: one survey collected data from 49 State WAP agencies (including the coterminous 48 States and the District of Columbia), and the second survey collected data from 920 (or 81 percent) of the local WAP agencies.

Mihlmester, P.E.; Koehler, W.C. Jr.; Beyer, M.A. [Aspen Systems Corp., Oak Ridge, TN (United States). Applied Management Sciences Div.; Brown, M.A. [Oak Ridge National Lab., TN (United States); Beschen, D.A. Jr. [Department of Energy, Washington, DC (United States). Office of Weatherization Assistance Programs

1992-02-01T23:59:59.000Z

473

Interpreting Horizontal Well Flow Profiles and Optimizing Well Performance by Downhole Temperature and Pressure Data  

E-Print Network (OSTI)

Horizontal well temperature and pressure distributions can be measured by production logging or downhole permanent sensors, such as fiber optic distributed temperature sensors (DTS). Correct interpretation of temperature and pressure data can be used to obtain downhole flow conditions, which is key information to control and optimize horizontal well production. However, the fluid flow in the reservoir is often multiphase and complex, which makes temperature and pressure interpretation very difficult. In addition, the continuous measurement provides transient temperature behavior which increases the complexity of the problem. To interpret these measured data correctly, a comprehensive model is required. In this study, an interpretation model is developed to predict flow profile of a horizontal well from downhole temperature and pressure measurement. The model consists of a wellbore model and a reservoir model. The reservoir model can handle transient, multiphase flow and it includes a flow model and a thermal model. The calculation of the reservoir flow model is based on the streamline simulation and the calculation of reservoir thermal model is based on the finite difference method. The reservoir thermal model includes thermal expansion and viscous dissipation heating which can reflect small temperature changes caused by pressure difference. We combine the reservoir model with a horizontal well flow and temperature model as the forward model. Based on this forward model, by making the forward calculated temperature and pressure match the observed data, we can inverse temperature and pressure data to downhole flow rate profiles. Two commonly used inversion methods, Levenberg- Marquardt method and Marcov chain Monte Carlo method, are discussed in the study. Field applications illustrate the feasibility of using this model to interpret the field measured data and assist production optimization. The reservoir model also reveals the relationship between temperature behavior and reservoir permeability characteristic. The measured temperature information can help us to characterize a reservoir when the reservoir modeling is done only with limited information. The transient temperature information can be used in horizontal well optimization by controlling the flow rate until favorite temperature distribution is achieved. With temperature feedback and inflow control valves (ICVs), we developed a procedure of using DTS data to optimize horizontal well performance. The synthetic examples show that this method is useful at a certain level of temperature resolution and data noise.

Li, Zhuoyi

2010-12-01T23:59:59.000Z

474

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

475

Improved Fluid Flow Measurements: Feedwater Flow  

Science Conference Proceedings (OSTI)

This report describes the combined results of a utility survey and site visits concerning feedwater flow measurement in fossil-fueled power plants. In addition, a summary is provided of the technologies available to measure the volumetric feedwater flow rate in plants. This volumetric flow rate can be converted to a mass flow rate by knowing the pressure and temperature of the flow media. Velocity meters, differential pressure meters, and other closed-conduit flowmeters are discussed along with ...

2012-11-28T23:59:59.000Z