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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

Multiscale Simulations for Polymeric Flow  

E-Print Network [OSTI]

Multiscale simulation methods have been developed based on the local stress sampling strategy and applied to three flow problems with different difficulty levels: (a) general flow problems of simple fluids, (b) parallel (one-dimensional) flow problems of polymeric liquids, and (c) general (two- or three-dimensional) flow problems of polymeric liquids. In our multiscale methods, the local stress of each fluid element is calculated directly by performing microscopic or mesoscopic simulations according to the local flow quantities instead of using any constitutive relations. For simple fluids (a), such as the Lenard-Jones liquid, a multiscale method combining MD and CFD simulations is developed based on the local equilibrium assumption without memories of the flow history. (b), the multiscale method is extended to take into account the memory effects that arise in hydrodynamic stress due to the slow relaxation of polymer-chain conformations. The memory of polymer dynamics on each fluid element is thus resolved by performing MD simulations in which cells are fixed at the mesh nodes of the CFD simulations.For general (two- or three-dimensional) flow problems of polymeric liquids (c), it is necessary to trace the history of microscopic information such as polymer-chain conformation, which carries the memories of past flow history, along the streamline of each fluid element. A Lagrangian-based CFD is thus implemented to correctly advect the polymer-chain conformation consistently with the flow. On each fluid element, coarse-grained polymer simulations are carried out to consider the dynamics of entangled polymer chains that show extremely slow relaxation compared to microscopic time scales.

Takahiro Murashima; Takashi Taniguchi; Ryoichi Yamamoto; Shugo Yasuda

2011-01-06T23:59:59.000Z

2

Numerical simulation of electrokinetically driven micro flows  

E-Print Network [OSTI]

Spectral element based numerical solvers are developed to simulate electrokinetically driven flows for micro-fluidic applications. Based on these numerical solvers, basic phenomena and devices for electrokinetic applications in micro and nano flows...

Hahm, Jungyoon

2005-11-01T23:59:59.000Z

3

Magnetic Design for the PediaFlow Ventricular Assist Device  

E-Print Network [OSTI]

. The magnetic design includes permanent-magnet (PM) passive bearings for radial support of the rotor for rotation. These components are closely coupled both geometrically and magnetically, and were thereforeMagnetic Design for the PediaFlow Ventricular Assist Device *Myounggyu D. Noh, James F. Antaki

Paden, Brad

4

Assembly flow simulation of a radar  

SciTech Connect (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

5

Flowing Liquid Crystal Simulating the Schwarzschild Metric  

E-Print Network [OSTI]

We show how to simulate the equatorial section of the Schwarzschild metric through a flowing liquid crystal in its nematic phase. Inside a liquid crystal in the nematic phase, a traveling light ray feels an effective metric, whose properties are linked to perpendicular and parallel refractive indexes, $n_o$ e $n_e$ respectively, of the rod-like molecule of the liquid crystal. As these indexes depend on the scalar order parameter of the liquid crystal, the Beris-Edwards hydrodynamic theory is used to connect the order parameter with the velocity of a liquid crystal flow at each point. This way we calculate a radial velocity profile that simulates the equatorial section of the Schwarzschild metric, in the region outside of Schwarzschild's radius, in the nematic phase of the liquid crystal. In our model, the higher flow velocity can be of the order of some meters per second.

Erms R. Pereira; Fernando Moraes

2010-11-21T23:59:59.000Z

6

Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT  

E-Print Network [OSTI]

Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT Yan Zhan, Foluso Ladeinde Stony Brook University thSep.21th , 2010 #12;OutlineOutline · Straight Pipe flowStraight Pipe flow · Curved pipe flow #12;OutlineOutline · Straight Pipe flowStraight Pipe flow · Curved pipe flow #12

McDonald, Kirk

7

Adaptive LES Methodology for Turbulent Flow Simulations  

SciTech Connect (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

8

CFD simulation of neutral ABL flows Xiaodong Zhang  

E-Print Network [OSTI]

Title: CFD simulation of neutral ABL flows Division: Aero-elastic Design ­ Wind Energy Division Risø flow field over different terrains employing Fluent 6.3 software. How accurate the simulation could.5 Comparison and conclusion 22 3.6 Closure 24 4 CFD Simulation of the Askervein Hill 24 4.1 Simulation

9

High Fidelity Simulation of Complex Suspension Flow for Practical...  

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

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...

10

Sediment Transport in Shallow Subcritical Flow Disturbed by Simulated Rainfall  

E-Print Network [OSTI]

TR-14 1968 Sediment Transport in Shallow Subcritical Flow Disturbed by Simulated Rainfall J.L. Machemehl Texas Water Resources Institute Texas A&M University ...

Machemehl, J. L.

11

Direct numerical simulation of turbulent reacting flows  

SciTech Connect (OSTI)

The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

12

REYNOLDS STRESS MODEL IMPLEMENTATION FOR HYPERSONIC FLOW SIMULATIONS  

E-Print Network [OSTI]

REYNOLDS STRESS MODEL IMPLEMENTATION FOR HYPERSONIC FLOW SIMULATIONS Arianna Bosco, PhD student, 52056 Aachen, Germany Abstract The simulation of hypersonic flows presents some difficulties due of the model is analyzed. 1 Introduction The aerodynamic design of hypersonic inlets is a criti- cal issue

13

MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS  

E-Print Network [OSTI]

MULTI­TARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS RALF HARTMANN # Abstract. Important quantities in aerodynamic flow simulations are the aerodynamic force coe subject classifications. 65N12,65N15,65N30 1. Introduction. In aerodynamic computations like compressible

Hartmann, Ralf

14

MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS  

E-Print Network [OSTI]

MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS RALF HARTMANN Abstract. Important quantities in aerodynamic flow simulations are the aerodynamic force coefficients including Navier-Stokes equations AMS subject classifications. 65N12,65N15,65N30 1. Introduction. In aerodynamic

Hartmann, Ralf

15

Tritium flow through a non-symmetrical source. Simulation of gas flow through an injection hole  

E-Print Network [OSTI]

Tritium flow through a non-symmetrical source. Simulation of gas flow through an injection hole of source in injection rarefaction parameter µ0 viscosity of tritium at T0 Pa s 2 #12;Ll = 5074.5 Lr = 5007

Sharipov, Felix

16

Large-eddy simulation of multiphase flows in complex combustors  

E-Print Network [OSTI]

Large-eddy simulation of multiphase flows in complex combustors S. V. Apte1 , K. Mahesh2 , F. Ham1 to accurately predict reacting multi-phase flows in practical combustors involving complex physical phenomena-turbine combustor geometries to evaluate the predictions made for multiphase, turbulent flow. 1 Introduction

Mahesh, Krishnan

17

Classical noise assists the flow of quantum energy by `momentum rejuvenation'  

E-Print Network [OSTI]

An important challenge in quantum science is to fully understand the efficiency of energy flow in networks. Here we present a simple and intuitive explanation for the intriguing observation that optimally efficient networks are not purely quantum, but are assisted by some interaction with a `noisy' classical environment. By considering the system's dynamics in both the site-basis and the momentum-basis, we show that the effect of classical noise is to sustain a broad momentum distribution, countering the depletion of high mobility terms which occurs as energy exits from the network. This picture predicts that the optimal level of classical noise is reciprocally related to the linear dimension of the lattice; our numerical simulations verify this prediction to high accuracy for regular 1D and 2D networks over a range of sizes up to thousands of sites. This insight leads to the discovery that dramatic further improvements in performance occur when a driving field targets noise at the low mobility components.

Ying Li; Filippo Caruso; Erik Gauger; Simon C. Benjamin

2014-06-13T23:59:59.000Z

18

Grid adaptation for functional outputs of compressible flow simulations  

E-Print Network [OSTI]

An error correction and grid adaptive method is presented for improving the accuracy of functional outputs of compressible flow simulations. The procedure is based on an adjoint formulation in which the estimated error in ...

Venditti, David Anthony, 1973-

2002-01-01T23:59:59.000Z

19

Extinction Characteristics of Catalyst-Assisted Combustion in a Stagnation-Point Flow Reactor  

E-Print Network [OSTI]

-NOx combustion as would be the case in the gas turbine application. In a premixed combustion mode, increasedExtinction Characteristics of Catalyst-Assisted Combustion in a Stagnation-Point Flow Reactor of detailed surface and gas- phase chemical kinetic models. Parametric studies are con- ducted to investigate

Im, Hong G.

20

Numerical simulation of flow separation control by oscillatory fluid injection  

E-Print Network [OSTI]

NUMERICAL SIMULATION OF FLOW SEPARATION CONTROL BY OSCILLATORY FLUID INJECTION A Dissertation by CELERINO RESENDIZ ROSAS Submitted to the O?ce of Graduate Studies of Texas A&M University in partial ful?llment of the requirements for the degree... of DOCTOR OF PHILOSOPHY May 2005 Major Subject: Aerospace Engineering NUMERICAL SIMULATION OF FLOW SEPARATION CONTROL BY OSCILLATORY FLUID INJECTION A Dissertation by CELERINO RESENDIZ ROSAS Submitted to Texas A&M University in partial ful...

Resendiz Rosas, Celerino

2005-08-29T23:59:59.000Z

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.


21

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

22

Fluid Flow Simulation in Fractured Reservoirs  

E-Print Network [OSTI]

The purpose of this study is to analyze fluid flow in fractured reservoirs. In most petroleum reservoirs, particularly carbonate reservoirs and some tight sands, natural fractures play a critical role in controlling fluid ...

Sarkar, Sudipta

2002-01-01T23:59:59.000Z

23

MATHEMATICAL MODELING AND SIMULATION FOR FLUID FLOW IN POROUS MEDIA  

E-Print Network [OSTI]

1 MATHEMATICAL MODELING AND SIMULATION FOR FLUID FLOW IN POROUS MEDIA Ewing, Richard Texas A is to understand the complex chemical, physical, and fluid flow processes occurring in an underground porous medium with one pass through these four steps. Once a computer code has been developed which gives concrete

Ewing, Richard E.

24

Submarine landslide flows simulation through centrifuge modelling  

E-Print Network [OSTI]

) ........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 2.7: Failure at Helsinki Harbour , Finland in 1936 (after Andresen and Bjerrum, 1967... ) ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Figure 2.18: Energy conversion for debris flows (modified after Iverson, 1997) .......................................................................................... 50 Figure 2.19: Schematic cross-section defini ng H...

Gue, Chang Shin

2012-05-08T23:59:59.000Z

25

Simulation of dust streaming in toroidal traps: Stationary flows  

SciTech Connect (OSTI)

Molecular-dynamic simulations were performed to study dust motion in a toroidal trap under the influence of the ion drag force driven by a Hall motion of the ions in E x B direction, gravity, inter-particle forces, and friction with the neutral gas. This article is focused on the inhomogeneous stationary streaming motion. Depending on the strength of friction, the spontaneous formation of a stationary shock or a spatial bifurcation into a fast flow and a slow vortex flow is observed. In the quiescent streaming region, the particle flow features a shell structure which undergoes a structural phase transition along the flow direction.

Reichstein, Torben; Piel, Alexander [IEAP, Christian-Albrechts-Universitaet, D-24098 Kiel (Germany)

2011-08-15T23:59:59.000Z

26

Resistive MHD Simulations of Laminar Round Jets with Application to Magnetic Nozzle Flows  

E-Print Network [OSTI]

of simulating magnetic nozzle flows and other plasmas that cannot be easily replicated in ground facilities....

Araya, Daniel

2012-02-14T23:59:59.000Z

27

FRAC-STIM: A Physics-Based Fracture Simulation, /reservoir Flow...  

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

FRAC-STIM: A Physics-Based Fracture Simulation, reservoir Flow and Heat Transport Simulator(aka FALCON) FRAC-STIM: A Physics-Based Fracture Simulation, reservoir Flow and Heat...

28

MPSalsa 3D Simulations of Chemically Reacting Flows  

DOE Data Explorer [Office of Scientific and Technical Information (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.

29

Advanced computational simulation of flow phenomena associated with orifice meters  

SciTech Connect (OSTI)

This paper presents and discusses results from a series of computational fluid dynamics (CFD) simulations of fluid flow phenomena associated with orifice meters. These simulations were performed using a new, state-of-the-art CFD code developed at Southwest Research Institute. This code is based on new techniques designed to take advantage of parallel computers to increase computational performance and fidelity of simulation results. This algorithm uses a domain decomposition strategy to create grid systems for very complex geometries composed of simpler geometric subregions, allowing for the accurate representation of the fluid flow domain. The domain decomposition technique maps naturally to parallel computer architectures. Here, the concept of message-passing is used to create a parallel algorithm, using the Parallel Virtual Machine (PVM) library. This code is then used to simulate the flow through an orifice meter run consisting of an orifice with a beta ratio of 0.5 and air flowing at a Reynolds number of 91,100. The work discussed in this paper is but the first step in developing a Virtual Metering Research Facility to support research, analysis, and formulation of new standards for metering.

Freitas, C.J. [Southwest Research Inst., San Antonio, TX (United States)

1995-12-31T23:59:59.000Z

30

A MONTE CARLO SIMULATION OF WATER FLOW IN VARIABLY ...  

E-Print Network [OSTI]

A Monte Carlo simulation method is employed to study groundwater flow in variably saturated fractal porous ... Richards' equation which is solved using a hybridized mixed finite element procedure. ... INTRODUCTION ... This conclusion has led to the development of stochastic models for the basic un- ... different soils.

1910-10-30T23:59:59.000Z

31

Simulation of salt migrations in density dependent groundwater flow  

E-Print Network [OSTI]

and uses a finite element method for the simulation of groundwater flow in the lateral (2D) direction (third dimension) a finite difference method is used in the simula- tions. Numerical experiments are done of this thesis is to investigate the possibilities of modelling salt migrations in density dependent groundwater

Vuik, Kees

32

Simulations of Turbulent Flows with Strong Shocks and Density Variations  

SciTech Connect (OSTI)

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.

Zhong, Xiaolin

2012-12-13T23:59:59.000Z

33

Numerical simulation of laminar flow in a curved duct  

SciTech Connect (OSTI)

This paper describes numerical simulations that were performed to study laminar flow through a square duct with a 900 bend. The purpose of this work was two fold. First, an improved understanding was desired of the flow physics involved in the generation of secondary vortical flows in three-dimensions. Second, adaptive gridding techniques for structured grids in three- dimensions were investigated for the purpose of determining their utility in low Reynolds number, incompressible flows. It was also of interest to validate the commercial computer code CFD-ACE. Velocity predictions for both non-adaptive and adaptive grids are compared with experimental data. Flow visualization was used to examine the characteristics of the flow though the curved duct in order to better understand the viscous flow physics of this problem. Generally, moderate agreement with the experimental data was found but shortcomings in the experiment were demonstrated. The adaptive grids did not produce the same level of accuracy as the non-adaptive grid with a factor of four more grid points.

Lopez, A.R.; Oberkampf, W.L.

1995-01-01T23:59:59.000Z

34

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations  

E-Print Network [OSTI]

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations J 2004) An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation

Brenner, Donald W.

35

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; Graldine Pichot

2006-12-20T23:59:59.000Z

36

Simulations of ductile flow in brittle material processing  

SciTech Connect (OSTI)

Research is continuing on the effects of thermal properties of the cutting tool and workpiece on the overall temperature distribution. Using an Eulerian finite element model, diamond and steel tools cutting aluminum have been simulated at various, speeds, and depths of cut. The relative magnitude of the thermal conductivity of the tool and the workpiece is believed to be a primary factor in the resulting temperature distribution in the workpiece. This effect is demonstrated in the change of maximum surface temperatures for diamond on aluminum vs. steel on aluminum. As a preliminary step toward the study of ductile flow in brittle materials, the relative thermal conductivities of diamond on polycarbonate is simulated. In this case, the maximum temperature shifts from the rake face of the tool to the surface of the machined workpiece, thus promoting ductile flow in the workpiece surface.

Luh, M.H.; Strenkowski, J.S.

1988-12-01T23:59:59.000Z

37

Computer Simulation of Reservoir Depletion and Oil Flow from the Macondo Well Following the Deepwater  

E-Print Network [OSTI]

Computer Simulation of Reservoir Depletion and Oil Flow from the Macondo Well Following, 2010, Computer simulation of reservoir depletion and oil flow from the Macondo well following. ..................................................................................12 Figures Figure 1. Oblique schematic view of the M56 oil reservoir

38

Implicit Large Eddy Simulation of Cavitation in Micro Channel Flows  

E-Print Network [OSTI]

We present a numerical method for Large Eddy Simulations (LES) of compressible two-phase flows. The method is validated for the flow in a micro channel with a step-like restriction. This setup is representative for typical cavitating multi-phase flows in fuel injectors and follows an experimental study of Iben et al., 2010. While a diesel-like test fuel was used in the experiment, we solve the compressible Navier-Stokes equations with a barotropic equation of state for water and vapor and a simple phase-change model based on equilibrium assumptions. Our LES resolve all wave dynamics in the compressible fluid and the turbulence production in shear layers.

Hickel, S; Schmidt, S J

2014-01-01T23:59:59.000Z

39

Numerical Simulation of Bubble Formation in Co-Flowing Mercury  

SciTech Connect (OSTI)

In this work, we present computational fluid dynamics (CFD) simulations of helium bubble formation and detachment at a submerged needle in stagnant and co-flowing mercury. Since mercury is opaque, visualization of internal gas bubbles was done with proton radiography (pRad) at the Los Alamos Neutron Science Center (LANSCE2). The acoustic waves emitted at the time of detachment and during subsequent oscillations of the bubble were recorded with a microphone. The Volume of Fluid (VOF) model was used to simulate the unsteady two-phase flow of gas injection in mercury. The VOF model is validated by comparing detailed bubble sizes and shapes at various stages of the bubble growth and detachment, with the experimental measurements at different gas flow rates and mercury velocities. The experimental and computational results show a two-stage bubble formation. The first stage involves growing bubble around the needle, and the second follows as the buoyancy overcomes wall adhesion. The comparison of predicted and measured bubble sizes and shapes at various stages of the bubble growth and detachment is in good agreement.

Abdou, Ashraf A [ORNL; Wendel, Mark W [ORNL; Felde, David K [ORNL; Riemer, Bernie [ORNL

2008-01-01T23:59:59.000Z

40

Simulation of High Density Pedestrian Flow: Microscopic Model  

E-Print Network [OSTI]

In recent years modelling crowd and evacuation dynamics has become very important, with increasing huge numbers of people gathering around the world for many reasons and events. The fact that our global population grows dramatically every year and the current public transport systems are able to transport large amounts of people, heightens the risk of crowd panic or crush. Pedestrian models are based on macroscopic or microscopic behaviour. In this paper, we are interested in developing models that can be used for evacuation control strategies. This model will be based on microscopic pedestrian simulation models, and its evolution and design requires a lot of information and data. The people stream will be simulated, based on mathematical models derived from empirical data about pedestrian flows. This model is developed from image data bases, so called empirical data, taken from a video camera or data obtained using human detectors. We consider the individuals as autonomous particles interacting through socia...

Dridi, Mohamed H

2015-01-01T23:59:59.000Z

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.


41

Multiscale Simulation Framework for Coupled Fluid Flow and Mechanical Deformation  

SciTech Connect (OSTI)

A multiscale linear-solver framework for the pressure equation associated with flow in highly heterogeneous porous formations was developed. The multiscale based approach is cast in a general algebraic form, which facilitates integration of the new scalable linear solver in existing flow simulators. The Algebraic Multiscale Solver (AMS) is employed as a preconditioner within a multi-stage strategy. The formulations investigated include the standard MultiScale Finite-Element (MSFE) andMultiScale Finite-Volume (MSFV) methods. The local-stage solvers include incomplete factorization and the so-called Correction Functions (CF) associated with the MSFV approach. Extensive testing of AMS, as an iterative linear solver, indicate excellent convergence rates and computational scalability. AMS compares favorably with advanced Algebraic MultiGrid (AMG) solvers for highly detailed three-dimensional heterogeneous models. Moreover, AMS is expected to be especially beneficial in solving time-dependent problems of coupled multiphase flow and transport in large-scale subsurface formations.

Tchelepi, Hamdi

2014-11-14T23:59:59.000Z

42

Error estimation and anisotropic mesh refinement for 3d laminar aerodynamic flow simulations  

E-Print Network [OSTI]

Error estimation and anisotropic mesh refinement for 3d laminar aerodynamic flow simulations Tobias Leichta,b , Ralf Hartmann,a,b aInstitute of Aerodynamics and Flow Technology, DLR (German Aerospace Center-dimensional laminar aerodynamic flow simulations. The optimal order symmetric interior penalty discontinuous Galerkin

Hartmann, Ralf

43

Large-eddy simulation of swirling particle-laden flows in a coaxial-jet combustor  

E-Print Network [OSTI]

Large-eddy simulation of swirling particle-laden flows in a coaxial-jet combustor S.V. Apte a,* , K 2003 Abstract Large-eddy simulation (LES) of particle-laden, swirling flow in a coaxial-jet combustor;cyclone combustors, and biomass gasifiers (Lefebvre, 1989). The physics of such flows is extremely complex

Apte, Sourabh V.

44

Hydrodynamical adaptive mesh refinement simulations of turbulent flows - II. Cosmological simulations of galaxy clusters  

E-Print Network [OSTI]

The development of turbulent gas flows in the intra-cluster medium and in the core of a galaxy cluster is studied by means of adaptive mesh refinement (AMR) cosmological simulations. A series of six runs was performed, employing identical simulation parameters but different criteria for triggering the mesh refinement. In particular, two different AMR strategies were followed, based on the regional variability of control variables of the flow and on the overdensity of subclumps, respectively. We show that both approaches, albeit with different results, are useful to get an improved resolution of the turbulent flow in the ICM. The vorticity is used as a diagnostic for turbulence, showing that the turbulent flow is not highly volume-filling but has a large area-covering factor, in agreement with previous theoretical expectations. The measured turbulent velocity in the cluster core is larger than 200 km/s, and the level of turbulent pressure contribution to the cluster hydrostatic equilibrium is increased by using the improved AMR criteria.

L. Iapichino; J. C. Niemeyer

2008-07-01T23:59:59.000Z

45

Simulation of Flow and Transport at the Micro (Pore) Scale  

SciTech Connect (OSTI)

An important problem in porous media involves the ability of micron and submicron-sized biological particles such as viruses or bacteria to move in groundwater systems through geologic media characterized by rock or mixed gravel, clay and sand materials. Current simulation capabilities require properly upscaled (continuum) models of colloidal filtration and adsorption to augment existing theories of fluid flow and chemical transport. Practical models typically address flow and transport behavior in aquifers over distances of 1 to 10 km where, for example, fluid momentum balance is governed by the simple Darcy's Law as a function of a pressure gradient, elevation gradient and a medium-dependent permeability parameter. In addition to fluid advection, there are multiple transport processes occurring in these systems including diffusion, dispersion and chemical interactions with solids or other aqueous chemical species. Particle transport is typically modeled in the same way as dissolved species, except that additional loss terms are incorporated to model particle filtration (physical interception), adsorption (chemical interception) and inactivation. Proper resolution of these processes at the porous medium continuum scale constitutes an important closure problem in subsurface science. We present a new simulation capability based on enabling technologies developed for microfluidics applications to model transport of colloidal-sized particles at the microscale, with relevance to the pore scale in geophysical subsurface systems. Particulate is represented by a bead-rod polymer model and is fully-coupled to a Newtonian solvent described by Navier-Stokes. Finite differences are used to discretize the interior of the domain; a Cartesian grid embedded boundary/volume-of-fluid method is used near boundaries and interfaces. This approach to complex geometry is amenable to direct simulation on grids obtained from surface extractions of tomographic image data. Short-range interactions are included in the particle model. This capability has been previously demonstrated on polymer flow in spatially-resolved packed bed (3D) and post array (2D) systems. We also discuss the advantages of this approach for the development of high-resolution adaptive algorithms for multiscale continuum-particle and mesoscale coarse-grained molecular dynamics models.

Trebotich, D; Miller, G H

2007-04-05T23:59:59.000Z

46

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

47

A multiple temperature kinetic model and its application to micro-scale gas flow simulations  

E-Print Network [OSTI]

A multiple temperature kinetic model and its application to micro-scale gas flow simulations model, micro-scale flows. 1. Introduction Gas flows can be classified according to the flow regimes_pku@yahoo.com.cn Abstract This paper presents a numerical approach to solve the multiple temperature kinetic model (MTKM

Xu, Kun

48

Automation cueing modulates cerebral blood flow and vigilance in a simulated air traffic control task  

E-Print Network [OSTI]

Automation cueing modulates cerebral blood flow and vigilance in a simulated air traffic control: Automation; vigilance; cerebral blood flow; mental workload; attentional resources. Automation cueing operator, depending on automation reliability. To assess these effects, transcranial Doppler sonography

Parasuraman, Raja

49

Large-Eddy Simulation of the Bachalo-Johnson Flow, with Shock...  

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

Travin, New Technologies and Services, Ltd. Large-Eddy Simulation of the Bachalo-Johnson Flow, with Shock-Induced Separation PI Name: Philippe Spalart PI Email:...

50

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

51

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...

Alfred, Dicman

2004-09-30T23:59:59.000Z

52

GPU accelerated flow solver for direct numerical simulation of turbulent flows  

SciTech Connect (OSTI)

Graphical processing units (GPUs), characterized by significant computing performance, are nowadays very appealing for the solution of computationally demanding tasks in a wide variety of scientific applications. However, to run on GPUs, existing codes need to be ported and optimized, a procedure which is not yet standardized and may require non trivial efforts, even to high-performance computing specialists. In the present paper we accurately describe the porting to CUDA (Compute Unified Device Architecture) of a finite-difference compressible NavierStokes solver, suitable for direct numerical simulation (DNS) of turbulent flows. Porting and validation processes are illustrated in detail, with emphasis on computational strategies and techniques that can be applied to overcome typical bottlenecks arising from the porting of common computational fluid dynamics solvers. We demonstrate that a careful optimization work is crucial to get the highest performance from GPU accelerators. The results show that the overall speedup of one NVIDIA Tesla S2070 GPU is approximately 22 compared with one AMD Opteron 2352 Barcelona chip and 11 compared with one Intel Xeon X5650 Westmere core. The potential of GPU devices in the simulation of unsteady three-dimensional turbulent flows is proved by performing a DNS of a spatially evolving compressible mixing layer.

Salvadore, Francesco [CASPUR via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR via dei Tizii 6/b, 00185 Rome (Italy); Bernardini, Matteo, E-mail: matteo.bernardini@uniroma1.it [Department of Mechanical and Aerospace Engineering, University of Rome La Sapienza via Eudossiana 18, 00184 Rome (Italy)] [Department of Mechanical and Aerospace Engineering, University of Rome La Sapienza via Eudossiana 18, 00184 Rome (Italy); Botti, Michela [CASPUR via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR via dei Tizii 6/b, 00185 Rome (Italy)

2013-02-15T23:59:59.000Z

53

High Fidelity Simulation of Complex Suspension Flow for Practical...  

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

designs of concrete are developed to meet these needs, it is important to measure and control flow properties to satisfy performance specifications. Failure to control the flow...

54

LATEX TikZposter Simulation of two-phase flow for  

E-Print Network [OSTI]

Aachen University Simulation of two-phase flow for direct steam-generating solar thermal power plantsLATEX TikZposter Simulation of two-phase flow for direct steam-generating solar thermal power University Concentrating solar thermal power plants Concentrating solar thermal power (CSP) plants

Ábrahám, Erika

55

The simulation of free surface flows with Computational Fluid Dynamics B. Godderidge1  

E-Print Network [OSTI]

1 The simulation of free surface flows with Computational Fluid Dynamics B. Godderidge1 A of these applications make their simulation with computational fluid dynamics particularly challenging. The successful Computational fluid dynamics is a powerful and versatile tool for the analysis of flow problems encountered

56

Friction dependence of shallow granular flows from discrete par-ticle simulations  

E-Print Network [OSTI]

Friction dependence of shallow granular flows from discrete par- ticle simulations Anthony Thornton relation for the macroscopic bed friction or basal roughness obtained from micro-scale discrete particle simulations of steady flows. We systematically vary the bed friction by changing the contact friction

Al Hanbali, Ahmad

57

Comparison of Numerical Techniques Used for Simulating Variable-Density Flow and Transport Experiments  

E-Print Network [OSTI]

Comparison of Numerical Techniques Used for Simulating Variable-Density Flow and Transport code by simulating two new variable-density-flow and transport experimental data sets. The experiments transport of a sinking groundwater plume and a rising groundwater plume. The numerical techniques used

Clement, Prabhakar

58

Simulation of Biological Flow and Transport in Complex Geometries using Embedded Boundary /  

E-Print Network [OSTI]

Simulation of Biological Flow and Transport in Complex Geometries using Embedded Boundary / Volume for modeling polymer fluids in irregular microscale geometries that enables long-time simulation of validation the constitutive behavior of polymer fluids. Complex flow environment geometries are represented on Cartesian grids

59

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based  

E-Print Network [OSTI]

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also

Le Roy, Robert J.

60

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a  

E-Print Network [OSTI]

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a , Rafik ABSI 2 abenzaoui@gmail.com Keywords: turbulent flows, heat transfer, forced convection, low Reynolds number model data for Re = 150. Introduction Turbulent flow with heat transfer mechanism is of great importance from

Paris-Sud XI, Université de

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

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 Abstract This work takes place in steam generators flow studies and we consider here steady state three words: Steam Generator, Two-phase Flow, Finite element Email address: Marc.Grandotto@cea.fr (M

Paris-Sud XI, Université de

62

Turbulence prediction in two- and three-dimensional bundle flows using Large Eddy Simulation  

E-Print Network [OSTI]

TURBULENCE PREDICTION IN TWO- AND THREE-DIMENSIONAL BUNDLE FLOWS USING LARGE EDDY SIMULATION A Thesis by WAEL ABDUL-HAMID IBRAHIM Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... Prediction in Two- and Three-Dimensional Bundle Flows Using Large Eddy Simulation. (May 1994) Wael Abdul-Hamid Ibrahim, B. S. Alexandria University Chair of Advisory Committee: Dr. Yassin A. Hassan Flow turbulence is a familiar phenomenon in everyday life...

Ibrahim, Wael Abdul-Hamid

1994-01-01T23:59:59.000Z

63

Bluff Body Flow Simulation Using a Vortex Element Method  

SciTech Connect (OSTI)

Heavy ground vehicles, especially those involved in long-haul freight transportation, consume a significant part of our nation's energy supply. it is therefore of utmost importance to improve their efficiency, both to reduce emissions and to decrease reliance on imported oil. At highway speeds, more than half of the power consumed by a typical semi truck goes into overcoming aerodynamic drag, a fraction which increases with speed and crosswind. Thanks to better tools and increased awareness, recent years have seen substantial aerodynamic improvements by the truck industry, such as tractor/trailer height matching, radiator area reduction, and swept fairings. However, there remains substantial room for improvement as understanding of turbulent fluid dynamics grows. The group's research effort focused on vortex particle methods, a novel approach for computational fluid dynamics (CFD). Where common CFD methods solve or model the Navier-Stokes equations on a grid which stretches from the truck surface outward, vortex particle methods solve the vorticity equation on a Lagrangian basis of smooth particles and do not require a grid. They worked to advance the state of the art in vortex particle methods, improving their ability to handle the complicated, high Reynolds number flow around heavy vehicles. Specific challenges that they have addressed include finding strategies to accurate capture vorticity generation and resultant forces at the truck wall, handling the aerodynamics of spinning bodies such as tires, application of the method to the GTS model, computation time reduction through improved integration methods, a closest point transform for particle method in complex geometrics, and work on large eddy simulation (LES) turbulence modeling.

Anthony Leonard; Phillippe Chatelain; Michael Rebel

2004-09-30T23:59:59.000Z

64

Numerical simulation of three-dimensional electrical flow through geomaterials  

E-Print Network [OSTI]

components in different arrangements (Mitchell 1993; Shang et al. 1995). These are very simple models and have been verified by experiments that consider only one-dimensional flow of current. In actual practice, current flow is three-dimensional around... the source. Methods do not exist to analyze three-dimensional current flow through circuit elements other than resistors. Thus, there is a need to develop methods to overcome these shortcomings. Electrical cone penetrometers have been used to convey...

Akhtar, Anwar Saeed

1998-01-01T23:59:59.000Z

65

High-Fidelity Simulation of Complex Suspension Flow for Practical...  

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

to develop a fundamental framework to understand important physical mechanisms that control the flow of such complex fluid systems. Results from this study will advance the...

66

Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating  

E-Print Network [OSTI]

Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification ...

Li, Xian-Xiang

67

Calculation of unsteady turbulent flow around obstacles using the large eddy simulation turbulence model  

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 prevalent turbulence model, Large Eddy Simulation (LES), to study the flow past rectangular cylinders. In an attempt to use...

Helton, Donald McLean

2002-01-01T23:59:59.000Z

68

Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation  

E-Print Network [OSTI]

Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation Bubbles)). The validation is performed for the case of laser-induced cavitation bubbles collapsing in an infinite medium

69

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

70

Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions  

E-Print Network [OSTI]

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.

Nikolai V. Priezjev

2012-08-27T23:59:59.000Z

71

Edge-based Meshless Methods for Compressible Flow Simulations  

E-Print Network [OSTI]

are obtained for airfoils in transonic flow. Lift and drag coefficients also compare well to the finite volume, including (1) the application of certain artificial diffusion schemes to meshless methods within an edge

Jameson, Antony

72

Simulated Surface-Induced Thrombin Generation in a Flow Field  

E-Print Network [OSTI]

A computational model of blood coagulation is presented with particular emphasis on the regulatory effects of blood flow, spatial distribution of tissue factor (TF), and the importance of the thrombomodulin-activated protein ...

Jordan, S.W.

73

Low level jet development during a numerically simulated return flow event  

E-Print Network [OSTI]

of the obstacle. This simulation shows that the structure of the lower tropospheric air flow during a period of return flow is complex. When mid-level westerlies are weak, mesoscale processes govern the development of low level jets. As the westerly winds increase...

Igau, Richard Charles

1994-01-01T23:59:59.000Z

74

Simple Models of Zero-Net Mass-Flux Jets for Flow Control Simulations  

E-Print Network [OSTI]

Simple Models of Zero-Net Mass-Flux Jets for Flow Control Simulations Reni Raju Dynaflow Inc for modeling the dynamics of zero- net mass-flux (ZNMF) actuators, the computational costs associated-flow model. 1. INTRODUCTION Zero-net mass-flux (ZNMF) actuators or "synthetic jets" have potential

Mittal, Rajat

75

Simulation of Nondifferentiable Models for Groundwater Flow and C. T. Kelleya  

E-Print Network [OSTI]

1 Simulation of Nondifferentiable Models for Groundwater Flow and Transport C. T. Kelleya K. R frequently in models for groundwater flow and species transport. The van Genuchten and Mualem PSK relations. INTRODUCTION Nonsmooth, even non-Lipschitz continuous, constitutive laws are not uncommon in models

76

Recent Advances in Computational Techniques for Simulation of Flow in Porous Media  

E-Print Network [OSTI]

are also addressed. Introduction Modeling porous media flow processes is required in many science and engineering applications. Oil recovery, environmental hydrology and groundwater flow are a few drivers in the development of porous media simulation tools. Nowadays high resolution models are constructed as a result

Coutinho, Alvaro L. G. A.

77

Level Set Based Simulations of Two-Phase Oil-Water Flows in Pipes  

E-Print Network [OSTI]

application is the lubricated pipelining of crude oil by the addition of water. We want to e?ciently transportLevel Set Based Simulations of Two-Phase Oil-Water Flows in Pipes Hyeseon Shim July 31, 2000 Abstract We simulate the axisymmetric pipeline transportation of oil and water numerically under

Soatto, Stefano

78

Investigation and Simulation of Three--Phase Flow in Porous Media  

E-Print Network [OSTI]

. The first simulator uses the coupled pressure--saturation formulation with a fixed set of primary variables. Contaminants such as petroleum products and other organic compounds which can dissolve in the groundwater in petroleum engineer­ ing where multiphase flow was examined and first numerical simulations had been

Cirpka, Olaf Arie

79

Statistical Error in Particle Simulations of Low Mach Number Flows  

E-Print Network [OSTI]

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. Expressions for the fluid velocity, density and temperature are derived ...

Hadjiconstantinou, Nicolas G.

80

Annual Simulated and Observed Flow Volumes for Guadalupe  

E-Print Network [OSTI]

is funded by the Regional Monitoring Program for Water Quality in San Francisco Estuary. We gratefully Segmentation In-Steam Gauges (Flow and SSC) and Model Set-up Calero Stn. San Jose Stn. Alamitos Stn. Guadalupe). Suspended sediment concentration (SSC) measurements have been taken on a 15-minute basis in Guadalupe River

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

Visualizing flow patterns in coupled geomechanical simulation using streamlines  

E-Print Network [OSTI]

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...

Parihar, Prannay

2009-05-15T23:59:59.000Z

82

Numerical simulation of fluid flow in porous/fractured media  

SciTech Connect (OSTI)

Theoretical models of fluid flow in porous/fractured media can help in the design of in situ fossil energy and mineral extraction technologies. Because of the complexity of these processes, numerical solutions are usually required. Sample calculations illustrate the capabilities of present day computer models.

Travis B.J.; Cook, T.L.

1981-01-01T23:59:59.000Z

83

Direct numerical simulation of turbulent TaylorCouette flow  

E-Print Network [OSTI]

the flow is characterized by the radius ratio, ? = R1/R2, where R1 and R2 are the radii ... vortices at the critical onset Taylor number Tc (defined as the Taylor number at which ... Beyond 5 105Tc these turbulent vortices became fragmented and lost .... employ a stiffly stable velocity-correction-type scheme with a third-order...

2007-08-23T23:59:59.000Z

84

Numerical Simulations of Dynamos Generated in Spherical Couette Flows  

E-Print Network [OSTI]

at generating a self-sustained magnetic field. No dynamo action occurs for axisymmetric flow while we always, Forest et al., 2002). No self-sustained magnetic fields were observed in the parameter regime where of ferromagnetic impellers, a self-sustained magnetic field has been observed in the Von K´arm´an Sodium (VKS

Boyer, Edmond

85

Multiscale Modeling and Simulation of Fluid Flows in Inelastic Media  

E-Print Network [OSTI]

in porous media (e.g. soil), Elasticity equations in heterogeneous media (concrete, asphalt), etc porous media s The Fluid-Structure interaction (FSI) problem at the microscale and numerical methods with computational solutions s Numerical upscaling of flow in deformable porous media #12;- p. 3/42 Why homogenize

Popov, Peter

86

Large Eddy Simulations of Jet Flow Interactions Within Rod Bundles  

E-Print Network [OSTI]

The present work investigates the turbulent jet flow mixing of downward impinging jets within a staggered rod bundle based on previous experimental work. The two inlet jets had Reynold's numbers of 11,160 and 6,250 and were chosen to coincide...

Salpeter, Nathaniel O.

2010-07-14T23:59:59.000Z

87

Mechanistic Foam Flow Simulation in Heterogeneous and Multidimensional Porous Media  

E-Print Network [OSTI]

-scale simulation is a vital component of the engineering and economic evaluation of any enhanced oil recovery (EOR Copyright 1997, Society of Petroleum Engineers, Inc. Received for review, April 24, 1997 Revised, July 23 generation, and foam propagation in rock formations. Efficient application and evaluation of candidates

Patzek, Tadeusz W.

88

A low diffusive Lagrange-remap scheme for the simulation of violent air-water free-surface flows.  

E-Print Network [OSTI]

. The evolution of the interfaces between phases and the consecutive complex dynamics need to be simulatedA low diffusive Lagrange-remap scheme for the simulation of violent air-water free-surface flows. Introduction Simulation of free surface flows knows an increasing interest as an essential predictive tool

Boyer, Edmond

89

Dispersion of swimming algae in laminar and turbulent channel flows: theory and simulations  

E-Print Network [OSTI]

Algal swimming is often biased by environmental cues, e.g. gravitational and viscous torques drive cells towards downwelling fluid (gyrotaxis). In view of biotechnological applications, it is important to understand how such biased swimming affects cell dispersion in a flow. Here, we study the dispersion of gyrotactic swimming algae in laminar and turbulent channel flows. By direct numerical simulation (DNS) of cell motion within upwelling and downwelling channel flows, we evaluate time-dependent measures of dispersion for increasing values of the flow Peclet (Reynolds) numbers, Pe (Re). Furthermore, we derive an analytical `swimming Taylor-Aris dispersion' theory, using flow-dependent transport parameters given by existing microscopic models. In the laminar regime, DNS results and analytical predictions compare very well, providing the first confirmation that cells' response to flow is best described by the generalized-Taylor-dispersion microscopic model. We predict that cells drift along a channel faster th...

Croze, O A; Ahmed, M; Bees, M A; Brandt, L

2012-01-01T23:59:59.000Z

90

Simulation of heavy oil reservoir performance using a non-Newtonian flow model  

E-Print Network [OSTI]

. This reduction of viscosity as a function of shear rate has a significant effect on rates and other parameters when simulating reservoir performance. The objective of this study is to compare the simulation results of Newtonian and non-Newtonian oils under...)ected to increasing shear rate, the viscosity decreases. This behavior implies that the oil viscosity varies as a function of not only pressure, but also shear rate. This behavior is important when simulating heavy-oil reservoir performance. To simulate the flow...

Narahara, Gene Masao

1983-01-01T23:59:59.000Z

91

Interpreting Velocities from Heat-Based Flow Sensors by NumericalSimulation  

SciTech Connect (OSTI)

We have carried out numerical simulations of three-dimensional non-isothermal flow around an in situ heat-based flow sensor to investigate how formation heterogeneities can affect the interpretation of ground water flow velocities from this instrument. The flow sensor operates by constant heating of a 0.75 m long, 5 cm diameter cylindrical probe, which contains 30 thermistors in contact with the formation. The temperature evolution at each thermistor can be inverted to obtain an estimate of the ground water flow velocity vector using the standard interpretive method, which assumes that the formation is homogeneous. Analysis of data from heat-based flow sensors installed in a sand aquifer at the Former Fort Ord Army Base near Monterey, California suggested an unexpected component of downward flow. The magnitudes of the vertical velocities were expected to be much less than the horizontal velocities at this site because the sensors were installed just above a clay aquitard. Numerical simulations were conducted to examine how differences in thermal conductivities may lead to spurious indications of vertical flow velocities. We found that a decrease in the thermal conductivity near the bottom of the sensor can perturb the temperature profiles along the instrument in such a manner that analyses assuming homogeneous thermal conductivity could indicate a vertical flow component even though flow is actually horizontal. This work demonstrates how modeling can be used to simulate instrument response to formation heterogeneity, and shows that caution must be used in interpreting data from such devices using overly simplistic assumptions.

Su, Grace W.; Freifeld, Barry M.; Oldenburg, Curtis M.; Jordan,Preston D.; Daley, Paul F.

2005-06-13T23:59:59.000Z

92

Simulation of three-dimensional shear flow around a nozzle-afterbody at high speeds  

SciTech Connect (OSTI)

In this paper, turbulent shear flows at supersonic and hypersonic speeds around a nozzle-afterbody are simulated. The three-dimensional, Reynolds-averaged Navier-Stokes equations are solved by a finite-volume and implicit method. The convective and the pressure terms are differenced by an upwind-biased algorithm. The effect of turbulence is incorporated by a modified Baldwin-Lomax eddy viscosity model. The success of the standard Baldwin-Lomax model for this flow type is shown by comparing it to a laminar case. These modifications made to the model are also shown to improve flow prediction when compared to the standard Baldwin-Lomax model. These modifications to the model reflect the effects of high compressibility, multiple walls, vortices near walls, and turbulent memory effects in the shear layer. This numerically simulated complex flowfield includes a supersonic duct flow, a hypersonic flow over an external double corner, a flow through a non-axisymmetric, internal-external nozzle, and a three-dimensional shear layer. The specific application is for the flow around the nozzle-afterbody of a generic hypersonic vehicle powered by a scramjet engine. The computed pressure distributions compared favorably with the experimentally obtained surface and off-surface flow surveys.

Baysal, O.; Hoffman, W.B. (Mechanical Engineering and Mechanics Dept., Old Dominion Univ., Norfolk, VA (United States))

1992-06-01T23:59:59.000Z

93

Flame-wall interaction simulation in a turbulent channel flow  

SciTech Connect (OSTI)

The interaction between turbulent premixed flames and channel walls is studied. Combustion is represented by a simple irreversible reaction with a large activation temperature. A low heat release assumption is used, but feedback to the flowfield can be allowed through viscosity changes. The effect of wall distance on local and global flame structure is investigated. Quenching distances and maximum wall heat fluxed computed in laminar cases are compared to DNS results. It is found that quenching distances decrease and maximum heat fluxes increase relative to laminar flame values, scaling with the turbulent strain rate. It is shown that these effects are due to large coherent structures which push flame elements towards the wall. The effect of wall strain in flame-wall interaction is studied in a stagnation line flow; this is used to explain the DNS results. The effects of the flame on the flow through viscosity changes is studied. It is also shown that remarkable flame events are produced by flame interaction with a horseshoe vortex: burned gases are pushed towards the wall at high speed and induce quenching and high wall heat flux while fresh gases are expelled from the wall region and form finger-like structures. Effects of the wall on flame surface density are investigated.

Bruneaux, G.; Akselvoll, K.; Poinsot, T.; Ferziger, J.H.

1996-10-01T23:59:59.000Z

94

Programs for Laser-AO Assisted Integral-Field Spectrometers on Ionized Flows  

E-Print Network [OSTI]

(starburst galaxies) or by gas accretion (Herbig-Haro object [HHO] flows and AGN). I introduce some-Haro Outflows HHO's are second only to supernova remnants as laboratories for study of non- planar astrophysical shocks. Ionization is entirely local in HHO shocks. Because only the component of motion perpendicular

Cecil, Gerald

95

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

E-Print Network [OSTI]

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...

Ryu, Sangsoo

2005-02-17T23:59:59.000Z

96

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

SciTech Connect (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

97

Measurement of two-phase flow at the core upper plenum interface under simulated reflood conditions  

SciTech Connect (OSTI)

Objectives of the Instrument Development Loop program were to simulate flows at the core/upper plenum interface during the reflood phase of a LOCA and to develop instruments for measuring mass-flows at this interface. A tie plate drag body was developed and tested successfully, and the data obtained were shown to be equivalent to pressure drops. The tie-plate drag body gave useful measurements in pure downflow, and the drag/turbine combination correlates with mass flow for high upflow. (DLC)

Thomas, D.G.; Combs, S.K.; Bagwell, M.E.

1980-01-01T23:59:59.000Z

98

Accurate direct Eulerian simulation of dynamic elastic-plastic flow  

SciTech Connect (OSTI)

The simulation of dynamic, large strain deformation is an important, difficult, and unsolved computational challenge. Existing Eulerian schemes for dynamic material response are plagued by unresolved issues. We present a new scheme for the first-order system of elasto-plasticity equations in the Eulerian frame. This system has an intrinsic constraint on the inverse deformation gradient. Standard Godunov schemes do not satisfy this constraint. The method of Flux Distributions (FD) was devised to discretely enforce such constraints for numerical schemes with cell-centered variables. We describe a Flux Distribution approach that enforces the inverse deformation gradient constraint. As this approach is new and novel, we do not yet have numerical results to validate our claims. This paper is the first installment of our program to develop this new method.

Kamm, James R [Los Alamos National Laboratory; Walter, John W [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

99

Plasma flow measurements in a simulated low earth orbit plasma  

SciTech Connect (OSTI)

The employment of large, higher power solar arrays for space operation has been considered, taking into account a utilization of high operating voltages. In connection with the consideration of such arrays, attention must be given to the fact that the ambient environment of space contains a tenuous low energy plasma which can interact with the high voltage array causing power 'leakage' and arcing. An investigation has been conducted with the aim to simulate the behavior of such an array in low-earth-orbit (LEO). During the experiments, local concentrations of the 'leakage' current were observed when the panel was at a high voltage. These concentrations could overload or damage a small area of cells in a large string. It was hypothesized that this effect was produced by electrostatic focusing of the particles by the sheath fields. To verify this experimentally, an end-effect Langmuir probe was employed. The obtained results are discussed.

Gabriel, S.B. (California Institute of Technology, Jet Propulsion Laboratory, Electrical Power and Propulsion Section, Pasadena, CA); Mccoy, J.E. (NASA, Johnson Space Center, Houston, TX); Carruth, M.R. Jr. (NASA, Marshall Space Flight Center, Huntsville, AL)

1982-01-01T23:59:59.000Z

100

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

SciTech Connect (OSTI)

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

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

Multidimensional Simulation of Plasma in Argon through a Shock in Hypersonic Flow  

E-Print Network [OSTI]

Multidimensional Simulation of Plasma in Argon through a Shock in Hypersonic Flow Amrita K. Lonkar in gases at hypersonic speeds. A plasma is composed of multiple species in thermo-chemical nonequlibrium major advancements in the field of hypersonics in the past quarter century. Rocket- powered launch

Alonso, Juan J.

102

Multidimensional Simulation of Plasma in Argon through a Shock in Hypersonic Flow  

E-Print Network [OSTI]

Multidimensional Simulation of Plasma in Argon through a Shock in Hypersonic Flow Amrita K. Lonkar in gases at hypersonic speeds. A plasma is composed of multiple species in thermo-chemical nonequlibrium of hypersonics in the past quarter century. Rocket- powered launch vehicles typically achieve hypersonic speeds

Alonso, Juan J.

103

Extracting the Acoustic pressure field from Large Eddy Simulation of confined reactive flows  

E-Print Network [OSTI]

and non-premixed open flames3,4 as well as in more complex cases such as gas turbine combustors must be large enough to include the sources of noise as well as part of the acoustic near field.6 VeryExtracting the Acoustic pressure field from Large Eddy Simulation of confined reactive flows Camilo

Nicoud, Franck

104

MULTIPHASE FLOW SIMULATION WITH VARIOUS BOUNDARY CONDITIONS Z. CHEN, R. E. EWING, and M. ESPEDAL  

E-Print Network [OSTI]

commonly used boundary conditions for groundwater hydrology and petroleum engineering problems can­ water hydrology and petroleum engineering is considered. The phase flow equations are given be incorporated into the pressure­saturation formu­ lation. INTRODUCTION In petroleum reservoir simulation

Ewing, Richard E.

105

Mathematical Modeling and Simulation for Applications of Fluid Flow in Porous Media \\Lambda  

E-Print Network [OSTI]

Mathematical Modeling and Simulation for Applications of Fluid Flow in Porous Media \\Lambda Richard descriptions at various length scales, modeling the effects of this heterogeneity of the porous medium a computer code has been developed which gives concrete quantitative results for the total model, this out

Ewing, Richard E.

106

Flow Simulations of a Rotating MidSized Rim Driven Wind Turbine  

E-Print Network [OSTI]

Flow Simulations of a Rotating MidSized Rim Driven Wind Turbine Bryan E. Kaiser1 , Andrew B: poroseva@unm.edu Introduction Conventional horizontal axis wind turbines (HAWTs) require harvesting. To overcome this limitation, small to midsized wind turbine designs capable of power

Maccabe, Barney

107

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 for studying the fate and transport of chemicals in soil. Large-scale field lysimeters are used to assess pesticide behaviour and radionuclide transport, and are assumed to represent natural field conditions better

Flury, Markus

108

3D MHD Free Surface Fluid Flow Simulation Based on Magnetic-Field Induction Equations  

E-Print Network [OSTI]

1 3D MHD Free Surface Fluid Flow Simulation Based on Magnetic-Field Induction Equations H.L. HUANG Huang@fusion.ucla.edu Abstract: The purpose of this paper is to present our recent efforts on 3D MHD-plane magnetic field configurations have shown that 3D MHD effects from a surface normal field gradient cause

California at Los Angeles, University of

109

Large Eddy Simulation Analysis of Flow Field Inside a High-g Combustor  

E-Print Network [OSTI]

Large Eddy Simulation Analysis of Flow Field Inside a High-g Combustor C. Heye , C. Lietz , J-compact combustors (UCC) are a technology for reducing the size of combustors. In these combustors the fuel and air results exhibit significant entrainment of fuel into recirculation zones inside the combustor, however

Raman, Venkat

110

A Coupled Approach for Plasma-Based Flow Control Simulations of Wing Sections  

E-Print Network [OSTI]

a role in momentum coupling, though as noted in Ref. 10 there is no significant heating of the airA Coupled Approach for Plasma-Based Flow Control Simulations of Wing Sections Datta V. Gaitonde Vehicles Directorate Kettering University Air Force Research Laboratory Flint, MI 48504 Wright

Roy, Subrata

111

Society of Petroleum Engineers Staggered In Time Coupling of Reservoir Flow Simulation and Geomechanical Defor-  

E-Print Network [OSTI]

Society of Petroleum Engineers SPE 51920 Staggered In Time Coupling of Reservoir Flow Simulation, The University of Texas at Austin Copyright 1999, Society of Petroleum Engineers, Inc. Thispaperwas by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented

Minkoff, Susan E.

112

Numerical simulations of gas-particle flows with combustion Julien NUSSBAUM  

E-Print Network [OSTI]

Numerical simulations of gas-particle flows with combustion Julien NUSSBAUM French-german Research. At the initial time, the mixture of gas-powder grains is contained in the combustion chamber, limited gas species. The pressure increases in the combustion chamber, while the front flame propagates

Paris-Sud XI, Université de

113

Cosmological MHD simulation of a cooling flow cluster  

E-Print Network [OSTI]

Various observations of magnetic fields in the Intra-Cluster Medium (ICM), most of the time restricted to cluster cores, point towards field strength of the order of a few microG (synchrotron radiation from radio relics and radio halos, inverse Compton radiation in X-rays and Faraday rotation measure of polarised background sources). Both the origin and the spatial structure of galaxy clusters magnetic fields are still under debate. In particular, the radial profile of the magnetic field, from the core of clusters to their outskirts, is of great importance for cosmic rays propagation within the Cosmic Web. In this letter, we highlight the importance of cooling processes in amplifying the magnetic field in the core of galaxy clusters up to one order of magnitude above the typical amplification obtained for a pure adiabatic evolution. We have performed a "zoom'' cosmological simulation of a 3 keV cluster, including dark matter and gas dynamics, atomic cooling, UV heating and star formation using the newly developed MHD solver in the AMR code RAMSES. Magnetic field amplification proceeds mainly through gravitational contraction. Shearing motions due to turbulence provide additional amplification in the outskirts of the cluster, while magnetic reconnection during mergers causes magnetic field dissipation in the core. Cooling processes have a strong impact on the magnetic field structure in the cluster. First, due to the sharp rise of the gas density in the centre, gravitational amplification is significantly amplified, when compared to the non--radiative run. Second, due to cooling processes, shearing motions are much stronger in the core than in the adiabatic case, leading to additional field amplification and no significant magnetic reconnection.

Y. Dubois; R. Teyssier

2008-03-31T23:59:59.000Z

114

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

SciTech Connect (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

115

Numerical simulations of aggregate breakup in bounded and unbounded turbulent flows  

E-Print Network [OSTI]

Breakup of small aggregates in fully developed turbulence is studied by means of direct numerical simulations in a series of typical bounded and unbounded flow configurations, such as a turbulent channel flow, a developing boundary layer and homogeneous isotropic turbulence. The simplest criterion for breakup is adopted, whereas aggregate breakup occurs when the local hydrodynamic stress $\\sigma\\sim \\varepsilon^{1/2}$, with $\\varepsilon$ being the energy dissipation at the position of the aggregate, overcomes a given threshold $\\sigma_\\mathrm{cr}$, which is characteristic for a given type of aggregates. Results show that the breakup rate decreases with increasing threshold. For small thresholds, it develops a universal scaling among the different flows. For high thresholds, the breakup rates show strong differences between the different flow configurations, highlighting the importance of non-universal mean-flow properties. To further assess the effects of flow inhomogeneity and turbulent fluctuations, theresults are compared with those obtained in a smooth stochastic flow. Furthermore, we discuss the limitations and applicability of a set of independent proxies.

Matthaus U. Babler; Luca Biferale; Luca Brandt; Ulrike Feudel; Ksenia Guseva; Alessandra S. Lanotte; Cristian Marchioli; Francesco Picano; Gaetano Sardina; Alfredo Soldati; Federico Toschi

2015-02-17T23:59:59.000Z

116

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

SciTech Connect (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 Laboratorys (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

117

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

SciTech Connect (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

118

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

SciTech Connect (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

119

Large-eddy simulation of turbulent cavitating flow in a micro channel  

SciTech Connect (OSTI)

Large-eddy simulations (LES) of cavitating flow of a Diesel-fuel-like fluid in a generic throttle geometry are presented. Two-phase regions are modeled by a parameter-free thermodynamic equilibrium mixture model, and compressibility of the liquid and the liquid-vapor mixture is taken into account. The Adaptive Local Deconvolution Method (ALDM), adapted for cavitating flows, is employed for discretizing the convective terms of the Navier-Stokes equations for the homogeneous mixture. ALDM is a finite-volume-based implicit LES approach that merges physically motivated turbulence modeling and numerical discretization. Validation of the numerical method is performed for a cavitating turbulent mixing layer. Comparisons with experimental data of the throttle flow at two different operating conditions are presented. The LES with the employed cavitation modeling predicts relevant flow and cavitation features accurately within the uncertainty range of the experiment. The turbulence structure of the flow is further analyzed with an emphasis on the interaction between cavitation and coherent motion, and on the statistically averaged-flow evolution.

Egerer, Christian P., E-mail: christian.egerer@aer.mw.tum.de; Hickel, Stefan; Schmidt, Steffen J.; Adams, Nikolaus A. [Institute of Aerodynamics and Fluid Mechanics, Technische Universitt Mnchen, Boltzmannstr. 15, 85748 Garching bei Mnchen (Germany)

2014-08-15T23:59:59.000Z

120

3D SPH Simulations of Shocks in Accretion Flows around black holes  

E-Print Network [OSTI]

We present the simulation of 3D time dependent flow of rotating ideal gas falling into a Schwarzschild black hole. It is shown that also in the 3D case steady shocks are formed in a wide range of parameters (initial angular momentum and thermal energy). We therefore highlight the stability of the phenomenon of shock formation in sub keplerian flows onto black holes, and reenforce the role of the shocks in the high luminosity emission from black hole candidates. The simulations have been performed using a parallelized code based on the Smoothed Particles Hydrodynamics method (SPH). We also discuss some properties of the shock problem that allow its use as a quantitative test of the accuracy of the used numerical method. This shows that the accuracy of SPH is acceptable although not excellent.

G. Gerardi; D. Molteni; V. Teresi

2005-01-25T23:59:59.000Z

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

All-optical cavity-based simulator of noise-assisted transport  

E-Print Network [OSTI]

Recent theoretical and experimental efforts have shown the remarkable and counter-intuitive role of noise in enhancing the transport efficiency of complex systems. Here, we realize simple, scalable, and controllable optical fiber cavity networks that allow us to simulate the performance of transport networks for different conditions of interference, dephasing and disorder. In particular, we experimentally demonstrate that the transport efficiency reaches a maximum when varying the external dephasing noise, i.e. a bell-like shape behavior that had been predicted only theoretically. These optical platforms are very promising simulators of transport phenomena, and could be used, in particular, to design and test optimal topologies of artificial light-harvesting structures for future solar energy technologies.

Viciani, Silvia; Bellini, Marco; Caruso, Filippo

2015-01-01T23:59:59.000Z

122

An implicit centered finite-difference simulation for free surface flows in a rocking tank  

E-Print Network [OSTI]

include the liquid movement in closed containers such as tank trucks on highways and railroads, liquid fuel tanks in space vehicles' and contained liquid cargo in oceangoing vessels. Interest in this particular fluid phenomenon has grown consider...AN IMPLICIT CENTERED FINITE-DIFFERENCE SIMULATION FOR FREE SURFACE FLOWS IN A ROCKING TANK A Thesis by WILLIAM EDWARD JOBST Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree...

Jobst, William Edward

1982-01-01T23:59:59.000Z

123

Rheological properties of soft-glassy flows from hydro-kinetic simulations  

E-Print Network [OSTI]

Based on numerical simulations of a lattice kinetic model for soft-glassy materials, we characterize the global rheology of a dense emulsion-like system, under three representative load conditions: Couette flow, time-oscillating Strain and Kolmogorov flow. It is found that in all cases the rheology is described by a Herschel-Bulkley (HB) relation, $\\sigma = {\\sigma}_{Y} + A S^{\\beta}$, with the yield stress ${\\sigma}_{Y}$ largely independent of the loading scenario. A proper rescaling of the HB parameters permits to describe heterogeneous flows with space-dependent stresses, based on the notion of cooperativity, as recently proposed to characterize the degree of non-locality of stress relaxation phenomena in soft-glassy materials.

R. Benzi; M. Bernaschi; M. Sbragaglia; S. Succi

2014-02-28T23:59:59.000Z

124

Theory and simulations of the scaling of magnetic reconnection with symmetric shear flow  

SciTech Connect (OSTI)

The scaling of magnetic reconnection in the presence of an oppositely directed sub-Alfvenic shear flow parallel to the reconnecting magnetic field is studied using analytical scaling arguments and two-dimensional two-fluid numerical simulations of collisionless (Hall) reconnection. Previous studies noted that the reconnection rate falls and the current sheet tilts with increasing flow speed, but no quantitative theory was presented. This study presents a physical model of the effect of shear flow on reconnection, resulting in expressions for the scaling of properties such as the reconnection rate, outflow speed, and thickness and length of the dissipation region, which are verified numerically. Differences between Hall and Sweet-Parker reconnection are pointed out. The tilting of the current sheet is explained physically and a quantitative prediction is presented and verified.

Cassak, P. A. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2011-07-15T23:59:59.000Z

125

Simulated effects of climate change on the Death Valley regional ground-water flow system, Nevada and California  

SciTech Connect (OSTI)

The US Geological Survey, in cooperation with the US Department of Energy, is evaluating the geologic and hydrologic characteristics of the Death Valley regional flow system as part of the Yucca Mountain Project. As part of the hydrologic investigation, regional, three-dimensional conceptual and numerical ground-water-flow models have been developed to assess the potential effects of past and future climates on the regional flow system. A simulation that is based on climatic conditions 21,000 years ago was evaluated by comparing the simulated results to observation of paleodischarge sites. Following acceptable simulation of a past climate, a possible future ground-water-flow system, with climatic conditions that represent a doubling of atmospheric carbon dioxide, was simulated. The steady-state simulations were based on the present-day, steady-state, regional ground-water-flow model. The finite-difference model consisted of 163 rows, 153 columns, and 3 layers and was simulated using MODFLOWP. Climate changes were implemented in the regional ground-water-flow model by changing the distribution of ground-water recharge. Global-scale, average-annual, simulated precipitation for both past- and future-climate conditions developed elsewhere were resampled to the model-grid resolution. A polynomial function that represents the Maxey-Eakin method for estimating recharge from precipitation was used to develop recharge distributions for simulation.

D`Agnese, F.A.; O`Brien, G.M.; Faunt, C.C.; San Juan, C.A.

1999-04-01T23:59:59.000Z

126

Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique  

SciTech Connect (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

127

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

SciTech Connect (OSTI)

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

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

2005-06-01T23:59:59.000Z

128

Simulation of Coupled Processes of Flow, Transport, and Storage of CO2 in Saline Aquifers  

SciTech Connect (OSTI)

This report is the final scientific one for the award DE- FE0000988 entitled Simulation of Coupled Processes of Flow, Transport, and Storage of CO2 in Saline Aquifers. The work has been divided into six tasks. In task, Development of a Three-Phase Non-Isothermal CO2 Flow Module, we developed a fluid property module for brine-CO2 mixtures designed to handle all possible phase combinations of aqueous phase, sub-critical liquid and gaseous CO2, supercritical CO2, and solid salt. The thermodynamic and thermophysical properties of brine-CO2 mixtures (density, viscosity, and specific enthalpy of fluid phases; partitioning of mass components among the different phases) use the same correlations as an earlier fluid property module that does not distinguish between gaseous and liquid CO2-rich phases. We verified the fluid property module using two leakage scenarios, one that involves CO2 migration up a blind fault and subsequent accumulation in a secondary parasitic reservoir at shallower depth, and another investigating leakage of CO2 from a deep storage reservoir along a vertical fault zone. In task, Development of a Rock Mechanical Module, we developed a massively parallel reservoir simulator for modeling THM processes in porous media brine aquifers. We derived, from the fundamental equations describing deformation of porous elastic media, a momentum conservation equation relating mean stress, pressure, and temperature, and incorporated it alongside the mass and energy conservation equations from the TOUGH2 formulation, the starting point for the simulator. In addition, rock properties, namely permeability and porosity, are functions of effective stress and other variables that are obtained from the literature. We verified the simulator formulation and numerical implementation using analytical solutions and example problems from the literature. For the former, we matched a one-dimensional consolidation problem and a two-dimensional simulation of the Mandel-Cryer effect. For the latter, we obtained a good match of temperature and gas saturation profiles, and surface uplift, after injection of hot fluid into a model of a caldera structure. In task, Incorporation of Geochemical Reactions of Selected Important Species, we developed a novel mathematical model of THMC processes in porous and fractured saline aquifers, simulating geo-chemical reactions associated with CO2 sequestration in saline aquifers. Two computational frameworks, sequentially coupled and fully coupled, were used to simulate the reactions and transport. We verified capabilities of the THMC model to treat complex THMC processes during CO2 sequestration by analytical solutions and we constructed reactive transport models to analyze the THMC process quantitatively. Three of these are 1D reactive transport under chemical equilibrium, a batch reaction model with equilibrium chemical reactions, and a THMC model with CO2 dissolution. In task Study of Instability in CO2 Dissolution-Diffusion-Convection Processes, We reviewed literature related to the study of density driven convective flows and on the instability of CO2 dissolution-diffusion-convection processes. We ran simulations that model the density-driven flow instability that would occur during CO2 sequestration. CO2 diffused through the top of the system and dissolved in the aqueous phase there, increasing its density. Density fingers formed along the top boundary, and coalesced into a few prominent ones, causing convective flow that forced the fluid to the system bottom. These simulations were in two and three dimensions. We ran additional simulations of convective mixing with density contrast caused by variable dissolved CO2 concentration in saline water, modeled after laboratory experiments in which supercritical CO2 was circulated in the headspace above a brine saturated packed sand in a pressure vessel. As CO2 dissolved into the upper part of the saturated sand, liquid phase density increases causing instability and setting off convective mixing. We obtained good agreement

Wu, Yu-Shu; Chen, Zizhong; Kazemi, Hossein; Yin, Xiaolong; Pruess, Karsten; Oldenburg, Curt; Winterfeld, Philip; Zhang, Ronglei

2014-09-30T23:59:59.000Z

129

Three-dimensional Simulation of Magnetized Cloud Fragmentation Induced by Nonlinear Flows and Ambipolar Diffusion  

E-Print Network [OSTI]

We demonstrate that the formation of collapsing cores in subcritical clouds is accelerated by nonlinear flows, by performing three-dimensional non-ideal MHD simulations. An initial random supersonic (and trans-Alfvenic) turbulent-like flow is input into a self-gravitating gas layer that is threaded by a uniform magnetic field (perpendicular to the layer) such that the initial mass-to-flux ratio is subcritical. Magnetic ambipolar diffusion occurs very rapidly initially due to the sharp gradients introduced by the turbulent flow. It subsequently occurs more slowly in the traditional near-quasistatic manner, but in regions of greater mean density than present in the initial state. The overall timescale for runaway growth of the first core(s) is several times, 10^6 yr, even though previous studies have found a timescale of several times, 10^7 yr when starting with linear perturbations and similar physical parameters. Large-scale supersonic flows exist in the cloud and provide an observationally testable distinguishing characteristic from core formation due to linear initial perturbations. However, the nonlinear flows have decayed sufficiently that the relative infall motions onto the first core are subsonic, as in the case of starting from linear initial perturbations. The ion infall motions are very similar to those of neutrals; however, they lag the neutral infall in directions perpendicular to the mean magnetic field direction and lead the neutral infall in the direction parallel to the mean magnetic field.

Takahiro Kudoh; Shantanu Basu

2008-04-27T23:59:59.000Z

130

A simulation code to assist designing space missions of the Airwatch type  

E-Print Network [OSTI]

The design of an Airwatch type space mission can greatly benefit from a flexible simulation code for establishing the values of the main parameters of the experiment. We present here a code written for this purpose. The cosmic ray primary spectrum at very high energies, the atmosphere modelling, the fluorescence yield, the photon propagation and the detector response are taken into account in order to optimize the fundamental design parameters of the experiment, namely orbit height, field of view, mirror radius, number of pixels of the focal plane, threshold of photo-detection. The optimization criterion will be to maximize counting rates versus mission cost, which imposes limits both on weight and power consumption. Preliminary results on signals with changing energy and zenith angle of incident particles are shown.

T. Montaruli; R. Bellotti; F. Cafagna; M. Circella; C. N. De Marzo; P. Lipari

1998-10-06T23:59:59.000Z

131

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

E-Print Network [OSTI]

simulation of reservoir depletion and oil flow from themodel included the oil reservoir and the well with a toppressures of the deep oil reservoir, to a two-phase oil-gas

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

132

General Relativistic Hydrodynamic Simulation of Accretion Flow from a Stellar Tidal Disruption  

E-Print Network [OSTI]

We study how the matter dispersed when a supermassive black hole tidally disrupts a star joins an accretion flow. Combining a relativistic hydrodynamic simulation of the stellar disruption with a relativistic hydrodynamics simulation of the tidal debris motion, we track such a system until ~80% of the stellar mass bound to the black hole has settled into an accretion flow. Shocks near the stellar pericenter and also near the apocenter of the most tightly-bound debris dissipate orbital energy, but only enough to make the characteristic radius comparable to the semi-major axis of the most-bound material, not the tidal radius as previously thought. The outer shocks are caused by post-Newtonian effects, both on the stellar orbit during its disruption and on the tidal forces. Accumulation of mass into the accretion flow is non-monotonic and slow, requiring ~3--10x the orbital period of the most tightly-bound tidal streams, while the inflow time for most of the mass may be comparable to or longer than the mass accu...

Shiokawa, Hotaka; Cheng, Roseanne M; Piran, Tsvi; Noble, Scott C

2015-01-01T23:59:59.000Z

133

A Unified Multi-Scale Model for Pore-Scale Flow Simulations in Soils  

SciTech Connect (OSTI)

Pore-scale simulations have received increasing interest in subsurface sciences to provide mechanistic insights into the macroscopic phenomena of water flow and reactive transport processes. The application of the pore scale simulations to soils and sediments is, however, challenged because of the characterization limitation that often only allows partial resolution of pore structure and geometry. A significant proportion of the pore space in soils and sediments is below the spatial resolution, forming a mixed media of pore and porous domains. Here we reported a unified multi-scale model (UMSM) that can be used to simulate water flow and transport in mixed media of pore and porous domains under both saturated and unsaturated conditions. The approach modifies the classic Navier-Stokes equation by adding a Darcy term to describe fluid momentum and uses a generalized mass balance equation for saturated and unsaturated conditions. By properly defining physical parameters, the UMSM can be applied in both pore and porous domains. This paper describes the set of equations for the UMSM, a series of validation cases under saturated or unsaturated conditions, and a real soil case for the application of the approach.

Yang, Xiaofan; Liu, Chongxuan; Shang, Jianying; Fang, Yilin; Bailey, Vanessa L.

2014-01-30T23:59:59.000Z

134

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

SciTech Connect (OSTI)

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

135

2-D Hypersonic Non-equilibrium Flow Simulation using r-p Adaptive Time-Implicit Discontinuous Galerkin Method  

E-Print Network [OSTI]

2-D Hypersonic Non-equilibrium Flow Simulation using r-p Adaptive Time-Implicit Discontinuous Aerospace Sciences Meeting #12;1 American Institute of Aeronautics and Astronautics 2-D Hypersonic Non Galerkin (DG) methods to 2-D hypersonic flow problems. Previous applications of DG method were limited

Roy, Subrata

136

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

DOE Data Explorer [Office of Scientific and Technical Information (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.

137

TOUGH2: A general-purpose numerical simulator for multiphase nonisothermal flows  

SciTech Connect (OSTI)

Numerical simulators for multiphase fluid and heat flows in permeable media have been under development at Lawrence Berkeley Laboratory for more than 10 yr. Real geofluids contain noncondensible gases and dissolved solids in addition to water, and the desire to model such `compositional` systems led to the development of a flexible multicomponent, multiphase simulation architecture known as MULKOM. The design of MULKOM was based on the recognition that the mass-and energy-balance equations for multiphase fluid and heat flows in multicomponent systems have the same mathematical form, regardless of the number and nature of fluid components and phases present. Application of MULKOM to different fluid mixtures, such as water and air, or water, oil, and gas, is possible by means of appropriate `equation-of-state` (EOS) modules, which provide all thermophysical and transport parameters of the fluid mixture and the permeable medium as a function of a suitable set of primary thermodynamic variables. Investigations of thermal and hydrologic effects from emplacement of heat-generating nuclear wastes into partially water-saturated formations prompted the development and release of a specialized version of MULKOM for nonisothermal flow of water and air, named TOUGH. TOUGH is an acronym for `transport of unsaturated groundwater and heat` and is also an allusion to the tuff formations at Yucca Mountain, Nevada. The TOUGH2 code is intended to supersede TOUGH. It offers all the capabilities of TOUGH and includes a considerably more general subset of MULKOM modules with added capabilities. The paper briefly describes the simulation methodology and user features.

Pruess, K. [Lawrence Berkeley Lab., CA (United States)

1991-06-01T23:59:59.000Z

138

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

SciTech Connect (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

139

Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics Processing Unit  

E-Print Network [OSTI]

Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics solve Navier-Stokes equations and other transportation equations for energy and species at a speed of 50 it in parallel on a Graphics Processing Unit (GPU). This study validated the FFD on the GPU by simulating

Chen, Qingyan "Yan"

140

Model simulation and experiments of flow and mass transport through a nano-material gas filter  

SciTech Connect (OSTI)

A computational model for evaluating the performance of nano-material packed-bed filters was developed. The porous effects of the momentum and mass transport within the filter bed were simulated. For the momentum transport, an extended Ergun-type model was employed and the energy loss (pressure drop) along the packed-bed was simulated and compared with measurement. For the mass transport, a bulk dsorption model was developed to study the adsorption process (breakthrough behavior). Various types of porous materials and gas flows were tested in the filter system where the mathematical models used in the porous substrate were implemented and validated by comparing with experimental data and analytical solutions under similar conditions. Good agreements were obtained between experiments and model predictions.

Yang, Xiaofan; Zheng, Zhongquan C.; Winecki, Slawomir; Eckels, Steve

2013-11-01T23:59:59.000Z

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141

Two-dimensional modeling of sodium boiling in a simulated LMFBR loss-of-flow test  

SciTech Connect (OSTI)

Loss-of-flow (LOF) accidents are of major importance in LMFBR safety. Tests have been performed to simulate the simultaneous failure of all primary pumps and reactor shutdown systems in a 37-pin electrically heated test bundle installed in the KNS sodium boiling loop at the Institute of Reactor Development, Karlsruhe. The tests simulated LOF conditions of the German prototype LMFBR, the SNR 300. The main objectives of these tests were to characterize the transient boiling development to cladding dryout and to provide data for validation of sodium boiling codes. One particular LOF test, designated L22, at full power was selected as a benchmark exercise for comparison of several codes at the Eleventh Meeting of the Liquid Metal Boiling Working Group (LMBWG) held in Grenoble, France, in October 1984. In this paper, the results of the calculations performed at ORNL with the two-dimensional (2-D) boiling code THORAX are presented.

Rose, S.D.

1984-01-01T23:59:59.000Z

142

Complete Numerical Simulation of Subcooled Flow Boiling in the Presence of Thermal and Chemical Interactions  

SciTech Connect (OSTI)

At present, guidelines for fuel cycle designs to prevent axial offset anomalies (AOA) in pressurized water reactor (PWR) cores are based on empirical data from several operating reactors. Although the guidelines provide an ad-hoc solution to the problem, a unified approach based on simultaneous modeling of thermal-hydraulics, chemical, and nuclear interactions with vapor generation at the fuel cladding surface does not exist. As a result, the fuel designs are overly constrained with a resulting economic penalty. The objective of present project is to develop a numerical simulation model supported by laboratory experiments that can be used for fuel cycle design with respect to thermal duty of the fuel to avoid economic penalty, as well as, AOA. At first, two-dimensional numerical simulation of the growth and departure of a bubble in pool boiling with chemical interaction is considered. A finite difference scheme is used to solve the equations governing conservation of mass, momentum, energy, and species concentration. The Level Set method is used to capture the evolving liquid-vapor interface. A dilute aqueous boron solution is considered in the simulation. From numerical simulations, the dynamic change in concentration distribution of boron during the bubble growth shows that the precipitation of boron can occur near the advancing and receding liquid-vapor interface when the ambient boron concentration level is 3,000 ppm by weight. Secondly, a complete three-dimensional numerical simulation of inception, growth and departure of a single bubble subjected to forced flow parallel to the heater surface was developed. Experiments on a flat plate heater with water and with boron dissolved in the water were carried out. The heater was made out of well-polished silicon wafer. Numbers of nucleation sites and their locations were well controlled. Bubble dynamics in great details on an isolated nucleation site were obtained while varying the wall superheat, liquid subcooling and flow velocity parametrically. Concentration variation of boron near the liquid-vapor interface was detected successfully with a newly developed miniature concentration sensor. The measured concentration variations at different radial locations from the center of cavity have the same trend as given by the numerical simulations. The deposition of boron was found near the nucleation site on the heater surface, which validates the numerical simulation. Subcooled flow boiling experiments at three pressures were performed on a nine-rod bundle with water and with boron dissolved in the water. The test runs were conducted with a wide range of mass fluxes (186 to 2800 kg/m2s) and heat fluxes (1.0 to 30.0 W/ cm2). Not only the variables required to develop mechanistic models for subcooled flow boiling were measured, but also the crud formation during boiling and its effect on the heat transfer process were investigated. (B204)

V.K. Dhir

2003-04-28T23:59:59.000Z

143

RAFT: A simulator for ReActive Flow and Transport of groundwater contaminants  

SciTech Connect (OSTI)

This report documents the use of the simulator RAFT for the ReActive flow and Transport of groundwater contaminants. RAFT can be used as a predictive tool in the design and analysis of laboratory and field experiments or it can be used for the estimation of model/process parameters from experiments. RAFT simulates the reactive transport of groundwater contaminants in one, two-, or three-dimensions and it can model user specified source/link configurations and arbitrary injection strategies. A suite of solvers for transport, reactions and regression are employed so that a combination of numerical methods best suited for a problem can be chosen. User specified coupled equilibrium and kinetic reaction systems can be incorporated into RAFT. RAFT is integrated with a symbolic computational language MAPLE, to automate code generation for arbitrary reaction systems. RAFT is expected to be used as a simulator for engineering design for field experiments in groundwater remediation including bioremediation, reactive barriers and redox manipulation. As an integrated tool with both the predictive ability and the ability to analyze experimental data, RAFT can help in the development of remediation technologies, from laboratory to field.

Chilakapati, A.

1995-07-01T23:59:59.000Z

144

Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors  

SciTech Connect (OSTI)

Because of the diversity of physical phenomena occuring in boiling, flashing, and bubble collapse, and of the length and time scales of LWR systems, it is imperative that the models have the following features: Both vapor and liquid phases (and noncondensible phases, if present) must be treated as compressible. Models must be mathematically and numerically well-posed. The models methodology must be multi-scale. A fundamental derivation of the multiphase governing equation system, that should be used as a basis for advanced multiphase modeling in LWR coolant systems, is given in the Appendix using the ensemble averaging method. The remainder of this work focuses specifically on the compressible, well-posed, and multi-scale requirements of advanced simulation methods for these LWR coolant systems, because without these are the most fundamental aspects, without which widespread advancement cannot be claimed. Because of the expense of developing multiple special-purpose codes and the inherent inability to couple information from the multiple, separate length- and time-scales, efforts within CASL should be focused toward development of a multi-scale approaches to solve those multiphase flow problems relevant to LWR design and safety analysis. Efforts should be aimed at developing well-designed unified physical/mathematical and high-resolution numerical models for compressible, all-speed multiphase flows spanning: (1) Well-posed general mixture level (true multiphase) models for fast transient situations and safety analysis, (2) DNS (Direct Numerical Simulation)-like models to resolve interface level phenmena like flashing and boiling flows, and critical heat flux determination (necessarily including conjugate heat transfer), and (3) Multi-scale methods to resolve both (1) and (2) automatically, depending upon specified mesh resolution, and to couple different flow models (single-phase, multiphase with several velocities and pressures, multiphase with single velocity and pressure, etc.) A unified, multi-scale approach is advocated to extend the necessary foundations and build the capability to simultaneously solve the fluid dynamic interface problems (interface resolution) as well as multiphase mixtures (homogenization).

R. A. Berry

2010-11-01T23:59:59.000Z

145

Simulation of conjugate driven cavity flow using a Chebyshev-Multidomain method  

SciTech Connect (OSTI)

The driven cavity problem with a temperature gradient is solved as a conjugate problem and compared with the nonconjugate case. Solid-fluid interface conditions are developed for the Chebyshev-Multidomain method which is used to simulate the coupled system. Steady-state solutions are examined at M = 0.3 for a square-cavity at Re = 350 and Re = 3,200 and for a cylindrical cavity at Re = 350. The results show that there are at least slight conjugate effects under most conditions but these effects are generally confined to the solution of the temperature distribution. Transient solutions at Re = 10{sup 4} show effects on the velocity field due to the chaotic nature of the flow.

Huckaby, E.D.; Catton, I.

1999-07-01T23:59:59.000Z

146

Inflow turbulence generation for eddy-resolving simulations of turbomachinery flows  

E-Print Network [OSTI]

A simple variant of recycling and rescaling method to generate inflow turbulence using unstructured grid CFD codes is presented. The method has been validated on large eddy simulation of spatially developing flat plate turbulent boundary layer. The proposed rescaling algorithm is based on the momentum thickness which is more robust and essentially obviates the need of finding the edge of the turbulent boundary layer in unstructured grid codes. Extension of this algorithm to hybrid RANS/LES type of approaches and for wall-bounded turbomachinery flows is also discussed. Results from annular diffuser with different inflow boundary layer characteristics is presented as an example application to show the utility of such an algorithm.

Arolla, Sunil K

2014-01-01T23:59:59.000Z

147

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

SciTech Connect (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

148

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

SciTech Connect (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

149

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

SciTech Connect (OSTI)

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

150

Thickness-based adaptive mesh refinement methods for multi-phase flow simulations with thin regions  

SciTech Connect (OSTI)

In numerical simulations of multi-scale, multi-phase flows, grid refinement is required to resolve regions with small scales. A notable example is liquid-jet atomization and subsequent droplet dynamics. It is essential to characterize the detailed flow physics with variable length scales with high fidelity, in order to elucidate the underlying mechanisms. In this paper, two thickness-based mesh refinement schemes are developed based on distance- and topology-oriented criteria for thin regions with confining wall/plane of symmetry and in any situation, respectively. Both techniques are implemented in a general framework with a volume-of-fluid formulation and an adaptive-mesh-refinement capability. The distance-oriented technique compares against a critical value, the ratio of an interfacial cell size to the distance between the mass center of the cell and a reference plane. The topology-oriented technique is developed from digital topology theories to handle more general conditions. The requirement for interfacial mesh refinement can be detected swiftly, without the need of thickness information, equation solving, variable averaging or mesh repairing. The mesh refinement level increases smoothly on demand in thin regions. The schemes have been verified and validated against several benchmark cases to demonstrate their effectiveness and robustness. These include the dynamics of colliding droplets, droplet motions in a microchannel, and atomization of liquid impinging jets. Overall, the thickness-based refinement technique provides highly adaptive meshes for problems with thin regions in an efficient and fully automatic manner.

Chen, Xiaodong [The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Vigor, E-mail: vigor.yang@aerospace.gatech.edu [School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150 (United States)

2014-07-15T23:59:59.000Z

151

Three-Dimensional Simulation of Forebay and Turbine Intakes Flows for the Bonneville Project  

SciTech Connect (OSTI)

Natural resource applications of computational fluid dynamics (CFD) models are becoming more frequent with the advances in computational power and the availability of commercial meshing software and verified CFD solver applications. The Bonneville Lock and Dam Project, constructed and operated by the U. S. Army Corps of Engineers, is the westernmost dam on the Columbia River, and is located about 40 miles upstream of Portland, Oregon. A set of 3D CFD models have been developed for the Bonneville Project forebay and turbine intakes; the CFD models provide a tool to predict the impact of proposed changes in operational rules both for the overall river flow patterns and near the turbine intakes. These models also offer rapid insight into the performance of proposed or existing hydraulic structures. The creation of a computational domain for Bonneville was complex and required the use of many software tools to integrate the diverse data sources that described the river and powerhouse geometry into a single computational domain. Once the computational mesh was created, flows were simulated by solving the Reynolds-averaged Navier-Stokes (RANS) equations together with a two-equation (k-epsilon) turbulence model. The model was validated using velocity data measured in reduced scale physical models and in the field.

Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Ebner, Laurie L.

2002-12-31T23:59:59.000Z

152

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

SciTech Connect (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

153

Numerical simulation of the flow field and the lifting forces in the bristle tip region of a brush seal  

E-Print Network [OSTI]

The complicated fluid flow at the tip of a typical bristle within a brush seal is simulated. A numerical model is developed to compute the three-dimensional details in the bristle tip region. Experimental and numerical leakage data are correlated...

Phung, Anh Ngoc

1995-01-01T23:59:59.000Z

154

Reduced-Order Models of Zero-Net Mass-Flux Jets for Large-Scale Flow Control Simulations  

E-Print Network [OSTI]

Reduced-Order Models of Zero-Net Mass-Flux Jets for Large-Scale Flow Control Simulations Reni Raju computational tools are well suited for modeling the dynamics of zero-net mass-flux actuators, the computational vorticity, (s-1 ) I. Introduction ERO-net mass-flux (ZNMF) actuators or "synthetic jets" have potential

Mittal, Rajat

155

Massive first-principles simulation provides insight into flame anchoring in a hydrogen-rich jet in cross-flow.  

E-Print Network [OSTI]

in cross-flow. When gas turbine designers want to use gasified biomass for stationary power generation is far more reactive than the methane that is the traditional gas turbine fuel. This reactivity leads Science Simulations Provide New Insights to Aid Hydrogen Gas Turbine Development NREL Highlights SCIENCE

156

Lattice Boltzmann method and gas-kinetic BGK scheme in the low-Mach number viscous flow simulations  

E-Print Network [OSTI]

and collisions process. On the other hand, the gas-kinetic BGK scheme is a finite volume scheme, where the timeLattice Boltzmann method and gas-kinetic BGK scheme in the low-Mach number viscous flow simulations method (LBM) and the gas-kinetic BGK scheme are based on the numerical discretization of the Boltzmann

Xu, Kun

157

Control-volume method for numerical simulation of two-phase immiscible flow in two-and  

E-Print Network [OSTI]

Hydrology: Groundwater hydrology; 3210 Mathematical Geophysics: Modeling; 3230 Mathematical Geophysics. This concept, which is often referred to as the discrete-fracture model, has a significant effect. Introduction [2] There is wide interest in the numerical simulation of multiphase flow in fractured

Firoozabadi, Abbas

158

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

SciTech Connect (OSTI)

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

159

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

SciTech Connect (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

160

Investigation of basic processes in a lithium Lorentz force accelerator through plasma flow simulation  

E-Print Network [OSTI]

". Presently Assistant Professor, Physics Department, Whitworth College, WA. Chief Scientist at the Electric such as robotic and piloted exploration of the moon, mars and the outer planets, had been shown[6

Choueiri, Edgar

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.


161

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

162

Evaluation of a CFD-model for simulation of simplified flow conditioners  

SciTech Connect (OSTI)

Perforated plate flow conditioners are used to generate a fully developed turbulent flow profile upstream of an orifice meter. It is very time-consuming to measure the effect of a flow conditioner for different upstream flow profiles. Therefore a project is initiated to evaluate the performance of a computational fluid computer code for this purpose. If the code correctly predicts the flow characteristics downstream of more complex flow conditioners. In this study a k-{var_epsilon} CFD-model was used to predict the flow downstream of obstruction plates having one large or nine small holes. Both mean velocity, turbulent kinetic energy, k, and the dissipation rate of turbulent kinetic energy, {var_epsilon}, were calculated and compared against measured data. The results indicate that it is possible to predict the mean velocity well and that the accuracy of the predicted k and {var_epsilon} depends on the complexity of the flow.

Erdal, A. [Statoil/K-LAB, Haugesund (Norway); Torbergsen, L.E.; Rimestad, S.; Krogstad, P.A. [Norwegian Inst. of Technology, Trondheim (Norway)

1995-12-31T23:59:59.000Z

163

LARGE EDDY SIMULATION AND MEASUREMENTS IN A TURBULENT ROTOR-STATOR FLOW  

E-Print Network [OSTI]

). The flow has significant industrial applications, such as internal gas- turbine flows and computer hard model is based on Spectral Vanishing Viscosity (SVV). The key particularity of this model

Paris-Sud XI, Université de

164

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

E-Print Network [OSTI]

ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus Yanping Zhou Jingyi..., especially for those who ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 show some interest about high-efficiency systems like VRF, it becomes of interest to compare the VRF to other systems and evaluate VRF?s performance...

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

2006-01-01T23:59:59.000Z

165

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

SciTech Connect (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

166

Comparative Analysis of Natural Convection Flows Simulated by both the Conservation and Incompressible Forms of the Navier-Stokes Equations in a Differentially-Heated Square Cavity  

SciTech Connect (OSTI)

This report illustrates a comparative study to analyze the physical differences between numerical simulations obtained with both the conservation and incompressible forms of the Navier-Stokes equations for natural convection flows in simple geometries. The purpose of this study is to quantify how the incompressible flow assumption (which is based upon constant density advection, divergence-free flow, and the Boussinesq gravitational body force approximation) differs from the conservation form (which only assumes that the fluid is a continuum) when solving flows driven by gravity acting upon density variations resulting from local temperature gradients. Driving this study is the common use of the incompressible flow assumption in fluid flow simulations for nuclear power applications in natural convection flows subjected to a high heat flux (large temperature differences). A series of simulations were conducted on two-dimensional, differentially-heated rectangular geometries and modeled with both hydrodynamic formulations. From these simulations, the selected characterization parameters of maximum Nusselt number, average Nusselt number, and normalized pressure reduction were calculated. Comparisons of these parameters were made with available benchmark solutions for air with the ideal gas assumption at both low and high heat fluxes. Additionally, we generated body force, velocity, and divergence of velocity distributions to provide a basis for further analysis. The simulations and analysis were then extended to include helium at the Very High Temperature gas-cooled Reactor (VHTR) normal operating conditions. Our results show that the consequences of incorporating the incompressible flow assumption in high heat flux situations may lead to unrepresentative results. The results question the use of the incompressible flow assumption for simulating fluid flow in an operating nuclear reactor, where large temperature variations are present. The results show that the use of the incompressible flow assumption with the Boussinesq gravitational body force approximation should be restricted to flows where the density change of a fluid particle along a pathline is negligible.

Richard C. Martineau; Ray A. Berry; Aurlia Esteve; Kurt D. Hamman; Dana A. Knoll; Ryosuke Park; William Taitano

2009-01-01T23:59:59.000Z

167

Consistent modeling of hypersonic nonequilibrium flows using direct simulation Monte Carlo.  

E-Print Network [OSTI]

??Hypersonic flows involve strong thermal and chemical nonequilibrium due to steep gradients in gas properties in the shock layer, wake, and next to vehicle surfaces. (more)

Zhang, Chonglin

2013-01-01T23:59:59.000Z

168

A NEW PEMFC FLOW FIELD PLATE OPTIMIZATION COMPARISON - ANSYS FLUENT FUEL-CELL SIMULATION.  

E-Print Network [OSTI]

??The performance of a new cathode flow field plate located on a PEM fuel cell was compared to an industry standard and optimal serpentine design (more)

Soueidan, Ahmed Yassin

2012-01-01T23:59:59.000Z

169

Flume studies of sediment transportation in shallow flow with simulated rainfall  

E-Print Network [OSTI]

force exerted on a particle by flowing water, which according to Newton, was equal to Trr V 2 where s is a shape factor (0. 79 for spheres), g is the specific weight s of the particle, r is its radius, and V is the critical bottom velocity. cr... water pipe flow . Turbulent flow can be visualized as being divided into sheets of fluid having one velocity. These sheets are traversed by eddies, and in this manner the flow tends to establish a condition of equilibrium by a mixing process...

Nail, Frank Mitchell

2012-06-07T23:59:59.000Z

170

Simulating Electron Transport and Synchrotron Emission in Radio Galaxies: Shock Acceleration and Synchrotron Aging in Three-Dimensional Flows  

E-Print Network [OSTI]

We present the first three-dimensional MHD radio galaxy simulations that explicitly model transport of relativistic electrons, including diffusive acceleration at shocks as well as radiative and adiabatic cooling in smooth flows. We discuss three simulations of light Mach 8 jets, designed to explore the effects of shock acceleration and radiative aging on the nonthermal particle populations that give rise to synchrotron and inverse-Compton radiations. We also conduct detailed synthetic radio observations of our simulated objects. We have gained several key insights from this approach: 1. The jet head in these multidimensional simulations is extremely complex. The classical jet termination shock is often absent, but motions of the jet terminus spin a ``shock-web complex'' within the backflowing jet material of the head. 2. Understanding the spectral distribution of energetic electrons in these simulations relies partly upon understanding the shock-web complex, for it can give rise to distributions that confound interpretation in terms of the standard model for radiative aging of radio galaxies. 3. The magnetic field outside of the jet itself becomes very intermittent and filamentary in these simulations, yet adiabatic expansion causes most of the cocoon volume to be occupied by field strengths considerably diminished below the nominal jet value. Thus population aging rates vary considerably from point to point.

I. L. Tregillis; T. W. Jones; Dongsu Ryu

2001-04-18T23:59:59.000Z

171

Simulation assisted design of a gallium phosphide np photovoltaic junction Charles R. Allen, Jong-Hyeok Jeon , Jerry M. Woodall  

E-Print Network [OSTI]

University, 1205 W State Street, West Lafayette, IN, USA a r t i c l e i n f o Article history: Received 27 February 2010 Keywords: Gallium phosphide Solar cell Multi-junction CPV Simulation a b s t r a c with measurements of the dark and light response. The light current was measured under an illumination of air mass

Woodall, Jerry M.

172

FullSWOF: A software for overland flow simulation / FullSWOF : un logiciel pour la simulation du ruissellement  

E-Print Network [OSTI]

Overland flow on agricultural fields may have some undesirable effects such as soil erosion, flood and pollutant transport. To better understand this phenomenon and limit its consequences, we developed a code using state-of-the-art numerical methods: FullSWOF (Full Shallow Water equations for Overland Flow), an object oriented code written in C++. It has been made open-source and can be downloaded from http://www.univ-orleans.fr/mapmo/soft/FullSWOF/. The model is based on the classical system of Shallow Water (SW) (or Saint-Venant system). Numerical difficulties come from the numerous dry/wet transitions and the highly-variable topography encountered inside a field. It includes runon and rainfall inputs, infiltration (modified Green-Ampt equation), friction (Darcy-Weisbach and Manning formulas). First we present the numerical method for the resolution of the Shallow Water equations integrated in FullSWOF_2D (the two-dimension version). This method is based on hydrostatic reconstruction scheme, coupled with a ...

Delestre, Olivier; Darboux, Frdric; Du, Mingxuan; James, Francois; Laguerre, Christian; Lucas, Carine; Planchon, Olivier

2012-01-01T23:59:59.000Z

173

Numerical Simulation of Flow Field Inside a Squeeze Film Damper and the Study of the Effect of Cavitation on the Pressure Distribution  

E-Print Network [OSTI]

of SFDs can be expensive and time consuming. The current work simulates the flow field inside the dynamically deforming annular gap of a SFD using the commercial computational fluid dynamics (CFD) code Fluent and compares the results to the experimental...

Khandare, Milind Nandkumar

2012-02-14T23:59:59.000Z

174

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...

Yan, Bicheng

2013-07-15T23:59:59.000Z

175

Multiphase flow and Encapsulation simulations using the moment of fluid method 1  

E-Print Network [OSTI]

, spray cooling, icing, combustion and agricultural irrigation. The instability of the interface, mass exist for the accurate and effi- cient computation of multiphase flows. First, the density and viscosity

Sussman, Mark

176

A front-tracking method for the simulation of three-phase flow in porous media  

E-Print Network [OSTI]

, the simultaneous flow of oil, water, and gas in the reservoir. Practical examples include primary production below bubble point and with movable water, waterfloods in the presence of free gas, gas floods, and water

177

ITR/ACS: Simulation Flows with Dynamic Interfaces on MultiTeraflop Computers  

E-Print Network [OSTI]

, chemical, marine, materials, wind engineering sciences. These include largeamplitude vibrations such flexible aerodynamic components high aspect ratio wings blades; flows mixtures slurries; wind biofluids with elastic vessels; and materials phase transition problems. We particularly interested modeling

Antaki, James F.

178

PANS method of turbulence: simulation of high and low Reynolds number flows past a circular cylinder  

E-Print Network [OSTI]

cylinder are performed at ReD 140,000 and ReD 3900 using the PANS model. The high Reynolds number PANS results are compared with experimental results from Cantwell and Coles, Large Eddy Simulation results from Breuer, and Detached Eddy Simulation results...

Lakshmipathy, Sunil

2006-04-12T23:59:59.000Z

179

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

SciTech Connect (OSTI)

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

180

PROBABILISTIC SIMULATION OF SUBSURFACE FLUID FLOW: A STUDY USING A NUMERICAL SCHEME  

SciTech Connect (OSTI)

There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.

Buscheck, Timothy Eric

1980-03-01T23:59:59.000Z

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.


181

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

SciTech Connect (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

182

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 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...

Blake, Sarah Anne

2009-05-15T23:59:59.000Z

183

BREATH Version 1.1, Coupled flow and energy transport in porous media: Simulator description and user guide  

SciTech Connect (OSTI)

This document describes the BREATH computer code, including the mathematical and numerical formulation for the simulator, usage description, and sample input files with corresponding output files. The BREATH computer code is designed to simulate one-dimensional flow of a liquid phase and dispersive transport of the corresponding vapor species, coupled with energy transfer, in a heterogeneous porous medium. The BREATH simulator has been developed for use in auxiliary analyses which are a part of the Nuclear Regulatory Commission Iterative Performance Assessment program. The simulator was developed in response to the observation from Total System Performance Assessments by both the Nuclear Regulatory Commission and the US Department of Energy that total-system performance at the Yucca Mountain site in Nevada is highly sensitive to the infiltration rate. Accordingly, this first version of the code is primarily intended to simulate processes important to infiltration and evaporation in climatic and hydrologic near-surface environments representative of the Yucca Mountain site. The simulation model assumes that there is an immobile solid phase, a mobile liquid phase, and an optional infinitely mobile gas phase. The liquid may have an associated vapor species, assumed to be in equilibrium with the liquid phase. The vapor phase may only move via diffusion within the gas phase. Energy may be transported in the form of enthalpy, thermal conduction, and latent heat. The temperature range is assumed to be between 0 and 100{degree}C. Available boundary conditions include six liquid-phase conditions, four vapor-species conditions, and three energy conditions, all of which may be applied independently to either end of the domain. Meteorological conditions may also be input, thereby providing additional control over boundary fluxes. Boundary conditions may be updated as often as desired.

Stothoff, S.A.

1995-07-01T23:59:59.000Z

184

Numerical simulation of material and energy flow in an e-beam melt furnace  

SciTech Connect (OSTI)

A numerical analysis is made of the material and energy flow in an electron-beam furnace. Energy from an electron beam vaporizes metal confined in a water-cooled crucible. At the beam impact site a. recirculating liquid metal pool is surrounded by a shell of its own solid. A Galerkin finite element method is modified to solve for the flow and temperature fields along with interface locations. The deforming mesh is parameterized using spines that pivot and stretch as the interfaces move. Results are given for an aluminum vaporizer in which parametric variations are made in the e-beam power and liquid viscosity. The calculations reveal the importance of the coupling between the free boundaries and the flow and energy fields.

Westerberg, K.W.; McClelland, M.A. [Lawrence Livermore National Lab., CA (United States); Finlayson, B.A. [Washington Univ., Seattle, WA (United States). Dept. of Chemical Engineering

1993-12-01T23:59:59.000Z

185

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

SciTech Connect (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{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

186

A splitting method for numerical simulation of free surface flows of incompressible fluids with surface tension  

E-Print Network [OSTI]

with surface tension Kirill D. Nikitin Maxim A. Olshanskii Kirill M. Terekhov Yuri V. Vassilevski§ Abstract to surface tension forces. The method splits one time step into a semi-Lagrangian treatment of the surface models a free surface flow of viscous incompressible fluid subject to surface tension forces. Further

Olshanskii, Maxim A.

187

Theoretical and Numerical Simulation of Non-Newtonian Fluid Flow in Propped Fractures  

E-Print Network [OSTI]

the original gel. The residual gel exhibits a higher yield stress, and is difficult to remove after fracture closure. But non-Newtonian fluid has complicated rheological equation and its flow behavior in porous media is difficult to be described and modeled...

Ouyang, Liangchen

2013-12-10T23:59:59.000Z

188

Direct numerical simulation of a reacting turbulent channel flow with thermo-chemical ablation  

E-Print Network [OSTI]

species; 2) pyrolysis of the composite material resin (series of chemical reactions arising and multicompo- nent physics, multi-phase flow dynamics, thermo-structural mechanics of composite materials attack. Graphite and carbon-carbon composites are widely used because they offer excellent thermo

Nicoud, Franck

189

Numerical simulation of flow of shear-thinning fluids in corrugated channels  

E-Print Network [OSTI]

is subjected to a periodic increase and decrease in cross-section area. Such conditions are frequently observed in the flow of blood through blood vessels, movement of lubricating oils through the ground during the oil extraction process, in the process...

Aiyalur Shankaran, Rohit

2009-05-15T23:59:59.000Z

190

Numerical simulation of flow of shear-thinning fluids in corrugated channels  

E-Print Network [OSTI]

is subjected to a periodic increase and decrease in cross-section area. Such conditions are frequently observed in the flow of blood through blood vessels, movement of lubricating oils through the ground during the oil extraction process, in the process...

Aiyalur Shankaran, Rohit

2008-10-10T23:59:59.000Z

191

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

E-Print Network [OSTI]

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...

Rasmy Marsis, Emanuel 1983-

2012-08-16T23:59:59.000Z

192

A PARALLEL DYNAMIC-MESH LAGRANGIAN METHOD FOR SIMULATION OF FLOWS WITH DYNAMIC INTERFACES  

E-Print Network [OSTI]

abound in the aerospace, automotive, biomedical, chemical, marine, materials, and wind engineering ratio wings and blades; flows of mixtures and slurries; wind-induced deformation of towers, antennas for such problems, since interfaces are naturally represented and propagated. However, the material description

Antaki, James F.

193

ITR/ACS: Simulation of Flows with Dynamic Interfaces on Multi-Teraflop Computers  

E-Print Network [OSTI]

, materials, and wind engineering sciences. These include large-amplitude vibrations of such flexible aerodynamic components as high aspect ratio wings and blades; flows of mixtures and slurries; wind; interaction of biofluids with elastic vessels; and materials phase transition problems. We are particularly

Antaki, James F.

194

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

SciTech Connect (OSTI)

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

195

Gusty, gaseous flows of FIRE: galactic winds in cosmological simulations with explicit stellar feedback  

E-Print Network [OSTI]

We present an analysis of the galaxy-scale gaseous outflows from the FIRE (Feedback in Realistic Environments) simulations. This suite of hydrodynamic cosmological zoom simulations provides a sample of halos where star-forming giant molecular clouds are resolved to z=0, and features an explicit stellar feedback model on small scales. In this work, we focus on quantifying the gas mass ejected out of galaxies in winds and how this material travels through the halo. We correlate these quantities to star formation in galaxies throughout cosmic history. Our simulations reveal that a significant portion of every galaxy's evolution, particularly at high redshift, is dominated by bursts of star formation, which are followed by powerful gusts of galactic outflow that sweep up a large fraction of gas in the interstellar medium and send it through the circumgalactic medium. The dynamical effect of these outflows can significantly limit the amount of star formation within the affected galaxy. At low redshift, however, su...

Muratov, Alexander L; Faucher-Giguere, Claude-Andre; Hopkins, Philip F; Quataert, Eliot; Murray, Norman

2015-01-01T23:59:59.000Z

196

Simulations of Zonal Flow Damping and Electron Bernstein Waves in Helical Systems  

SciTech Connect (OSTI)

This work is divided into two different lines of research. The first one is devoted to the gyrokinetic simulations of ITG linear instabilities and ZF-GAM damping in multiple-helicity magnetic field configurations. The multiple helicity terms are required to study inward-shifted scenarios in LHD and are responsible for the improvement of the neoclassical helical ripple transport. It is thought that they also enhance the residual ZF in these inward shifted scenarios, thus reducing also the anomalous transport. These studies are to be the starting point of full non-linear simulations. In the second part, numerical simulations of Electron Bernstein Waves (EBW) are performed in order to justify the experimentally observed increase of the stored energy in the Compact Helical System (CHS) in NIFS, when EC waves are launched into a comparatively over-dense plasma. Calculations of ray-tracing, mode-conversion and power deposition of OXB converted waves are presented.

Ferrando i Margalet, S.; Yoshimura, Y.; Suzuki, C.; Shimizu, A. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Sugama, H.; Watanabe, T.-H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Graduate University for Advanced Studies (Sokendai), Toki, Gifu, 509-5292 (Japan)

2006-11-30T23:59:59.000Z

197

On the simulation of shock-driven material mixing in high-Re flows (u)  

SciTech Connect (OSTI)

Implicit large eddy simulation proposes to effectively rely on the use of subgrid modeling and filtering provided implicitly by physics capturing numerics. Extensive work has demonstrated that predictive simulations of turbulent velocity fields are possible using a class of high resolution, non-oscillatory finite-volume (NFV) numerical algorithms. Truncation terms associated with NFV methods implicitly provide subgrid models capable of emulating the physical dynamics of the unresolved turbulent velocity fluctuations by themselves. The extension of the approach to the substantially more difficult problem of under-resolved material mixing by an under-resolved velocity field has not yet been investigated numerically, nor are there any theories as to when the methodology may be expected to be successful. Progress in addressing these issues in studies of shock-driven scalar mixing driven by Ritchmyer-Meshkov instabilities will be reported in the context of ongoing simulations of shock-tube laboratory experiments.

Grinstein, Fernando F [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

198

Wake Flow Simulations for a Mid-Sized Rim Driven Wind Turbine  

SciTech Connect (OSTI)

The onshore land where wind farms with conventional wind turbines can be places is limited by various factors including a requirement for relatively high wind speed for turbines' efficient operations. Where such a requirement cannot be met, mid-and small-sized turbines can be a solution. In the current paper simulations for near and for wakes behind a mid-sized Rim Driven Wind Turbine developed by Keuka Energy LLC is analyzed. The purposes of this study is to better understand the wake structure for more efficient wind farm planning. Simulations are conducted with the commercial CFD software STARCCM+

Rob O. Hovsapian; Various

2014-06-01T23:59:59.000Z

199

Extraction of diffuse correlation spectroscopy flow index by integration of Nth-order linear model with Monte Carlo simulation  

SciTech Connect (OSTI)

Conventional semi-infinite solution for extracting blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements may cause errors in estimation of BFI (?D{sub B}) in tissues with small volume and large curvature. We proposed an algorithm integrating Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in tissue for the extraction of ?D{sub B}. The volume and geometry of the measured tissue were incorporated in the Monte Carlo simulation, which overcome the semi-infinite restrictions. The algorithm was tested using computer simulations on four tissue models with varied volumes/geometries and applied on an in vivo stroke model of mouse. Computer simulations shows that the high-order (N???5) linear algorithm was more accurate in extracting ?D{sub B} (errors?simulations, demonstrating the robustness of the linear algorithm. DCS with the high-order linear algorithm shows the potential for the inter-subject comparison and longitudinal monitoring of absolute BFI in a variety of tissues/organs with different volumes/geometries.

Shang, Yu; Lin, Yu; Yu, Guoqiang, E-mail: guoqiang.yu@uky.edu [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States); Li, Ting [Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States); State Key Laboratory for Electronic Thin Film and Integrated Device, University of Electronic Science and Technology of China, Chengdu 610054 (China); Chen, Lei; Toborek, Michal [Department of Neurosurgery, University of Kentucky, Lexington, Kentucky 40536 (United States)

2014-05-12T23:59:59.000Z

200

SIMULATION OF CROSS FLOW PAST A TUBE BANK EMPLOYING AN ADAPTIVE PARALLEL / VECTOR FINITE ELEMENT PROCEDURE  

E-Print Network [OSTI]

Engenharia Civil, COPPE Comissão Nacional de Energia Nuclear Universidade Federal do Rio de Janeiro 21945­970 ­ Rio de Janeiro ­ RJ ­ Brasil 21945­910 ­ Rio de Janeiro ­ RJ ­ Brasil SUMMARY The numerical simulation

Coutinho, Alvaro L. G. A.

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

Measurement and modelling of high-resolution flow-velocity data under simulated rainfall on a  

E-Print Network [OSTI]

solves the Saint- Venant equations in 2D, MAHLERAN uses a 1D kinematic wave in the slope direction 0022 in revised form 5 July 2007; accepted 23 July 2007 KEYWORDS Rainfall-simulation; Water erosion; Erosion algorithm that is close in principle to the diffusion-wave equation in 2D. The Darcy­ Weisbach friction

202

High-Performance Reactive Fluid Flow Simulations Using Adaptive Mesh Refinement on Thousands of Processors  

E-Print Network [OSTI]

Thermonuclear Flashes at the University of Chicago. FLASH is a modular, adaptive mesh, parallel simulation code to thermonuclear reactions in supernovae and novae. The FLASH code was designed to study thermonuclear flashes Thermonuclear Flashes, The University of Chicago, Chicago, IL 60637 2 Center for Applied Scientific Computing

Rhoads, James

203

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

E-Print Network [OSTI]

?....................................................................................26 V CFD MODELLING ...................................................................................28 V.1 Computational Fluid Dynamics (CFD) ..........................................28 V.2 The History.... Hassan The premise of the work presented here is to use a common analytical tool, Computational Fluid Dynamics (CFD), along with different turbulence models. Eddy viscosity models as well as state-of-the-art Large Eddy Simulation (LES) were...

Yesilyurt, Gokhan

2004-09-30T23:59:59.000Z

204

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

E-Print Network [OSTI]

and kitchen fittings. Facing the increasing demands for saving energy and water, TOTO has always targeted schemes and port the code to the GPU platforms to accelerate the large scale computations for real** Tokyo Institute of Technology, Department of energy sciences Numerical simulation of air

Furui, Sadaoki

205

Comparative evaluation of network flow programming and conventional reservoir system simulation models  

E-Print Network [OSTI]

ANALYSIS MODELS Operating river/reservoir systems in an optimal manner is an important and com- plex area of water resources planning and management. Reservoir system operation involves: allocating storage capacity and water resources between multiple... broad array of analysis capabilities, have been developed over the past several decades to support planning studies and management decisions. Reservoir system analysis models can be categorized as (I) simulation models, (2) optimization models...

Yerramreddy, Anilkumar

1993-01-01T23:59:59.000Z

206

Lattice-Boltzmann Simulations of Multiphase Flows in Gas-Diffusion-Layer (GDL) of a PEM Fuel Cell  

SciTech Connect (OSTI)

Improved power density and freeze-thaw durability in automotive applications of Proton Exchange Membrane Fuel Cells (PEMFCs) requires effective water management at the membrane. This is controlled by a porous hydrophobic gas-diffusion-layer (GDL) inserted between the membrane catalyst layer and the gas reactant channels. The GDL distributes the incoming gaseous reactants on the catalyst surface and removes excess water by capillary action. There is, however, limited understanding of the multiphase, multi-component transport of liquid water, vapor and gaseous reactants within these porous materials. This is due primarily to the challenges of in-situ diagnostics for such thin (200 -? 300 {microns}), optically opaque (graphite) materials. Transport is typically analyzed by fitting Darcy's Law type expressions for permeability, in conjunction with capillary pressure relations based on formulations derived for media such as soils. Therefore, there is significant interest in developing predictive models for transport in GDLs and related porous media. Such models could be applied to analyze and optimize systems based on the interactions between cell design, materials, and operating conditions, and could also be applied to evaluating material design concepts. Recently, the Lattice Boltzmann Method (LBM) has emerged as an effective tool in modeling multiphase flows in general, and flows through porous media in particular. This method is based on the solution of a discrete form of the well-known Boltzmann Transport Equation (BTE) for molecular distribution, tailored to recover the continuum Navier-Stokes flow. The kinetic theory basis of the method allows simple implementation of molecular forces responsible for liquid-gas phase separation and capillary effects. The solution advances by a streaming and collision type algorithm that makes it suitable to implement for domains with complex boundaries. We have developed both single and multiphase LB models and applied them to simulate flow through porous GDL materials. We will present an overview of the methods as implemented, verification studies for both microstructure reconstruction and transport simulations, and application to single- and two-phase transport in GDL structures. The applications studies are designed to both improve understanding of transport within a given structure, and to investigate possible routes for improving material properties through microstructure design.

Shiladitya Mukherjeea; J. Vernon Cole; Kunal Jainb; Ashok Gidwania

2008-11-01T23:59:59.000Z

207

On numerical simulation of flow, heat transfer and combustion processes in tangentially-fired furnace  

SciTech Connect (OSTI)

In this work, an Eulerian/Lagrangian approach has been employed to investigate numerically flow characteristics, heat transfer and combustion processes inside corner-fired power plant boiler furnace. To avoid pseudo-diffusion that is significant in modeling tangentially-fired furnaces, some attempts have been made at improving the finite-difference scheme. Comparisons have been made between standard {kappa}-{epsilon} model and RNG {kappa}-{epsilon} model. Some new developments on turbulent diffusion of particles are taken into account in an attempt to improve computational accuracy. Finally, temperature deviation is studied numerically so as to gain deeper insight into tangentially fired furnace.

Sun, P.; Fan, J.; Cen, K.

1999-07-01T23:59:59.000Z

208

Identification of whistling ability of a single hole orifice from an incompressible flow simulation  

SciTech Connect (OSTI)

Pure tone noise from orifices in pipe result from vortex shedding with lock-in. Acoustic amplification at the orifice is coupled to resonant condition to create self-sustained oscillations. One key feature of this phenomenon is hence the ability of an orifice to amplify acoustic waves in a given range of frequencies. Here a numerical investigation of the linear response of an orifice is undertaken, with the support of experimental data for validation. The study deals with a sharp edge orifice. Its diameter equals to 0.015 m and its thickness to 0.005 m. The pipe diameter is 0.030 m. An air flow with a Mach number 0.026 and a Reynolds number 18000 in the main pipe is present. At such a low Mach number; the fluid behavior can reasonably be described as locally incompressible. The incompressible Unsteady Reynolds Averaged Navier-Stokes (URANS) equations are solved with the help of a finite volume fluid mechanics software. The orifice is submitted to an average flow velocity, with superimposed small harmonic perturbations. The harmonic response of the orifice is the difference between the upstream and downstream pressures, and a straightforward calculation brings out the acoustic impedance of the orifice. Comparison with experiments shows that the main physical features of the whistling phenomenon are reasonably reproduced. (authors)

Lacombe, Romain; Moussou, Pierre [LaMSID - UMR EDF/CNRS/CEA, DEN-DM2S, 8193 EDF R et D, 1 avenue du General de Gaulle, 92141 Clamart Cedex (France); Auregan, Yves [Universite du Maine, Le Mans, (France)

2012-07-01T23:59:59.000Z

209

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

SciTech Connect (OSTI)

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

210

MOLECULAR-KINETIC SIMULATIONS OF ESCAPE FROM THE EX-PLANET AND EXOPLANETS: CRITERION FOR TRANSONIC FLOW  

SciTech Connect (OSTI)

The equations of gas dynamics are extensively used to describe atmospheric loss from solar system bodies and exoplanets even though the boundary conditions at infinity are not uniquely defined. Using molecular-kinetic simulations that correctly treat the transition from the continuum to the rarefied region, we confirm that the energy-limited escape approximation is valid when adiabatic expansion is the dominant cooling process. However, this does not imply that the outflow goes sonic. Rather large escape rates and concomitant adiabatic cooling can produce atmospheres with subsonic flow that are highly extended. Since this affects the heating rate of the upper atmosphere and the interaction with external fields and plasmas, we give a criterion for estimating when the outflow goes transonic in the continuum region. This is applied to early terrestrial atmospheres, exoplanet atmospheres, and the atmosphere of the ex-planet, Pluto, all of which have large escape rates.

Johnson, Robert E.; Volkov, Alexey N.; Erwin, Justin T. [Engineering Physics, University of Virginia, Charlottesville, VA 22904-4745 (United States)

2013-05-01T23:59:59.000Z

211

Analysis of turbulent transport and mixing in transitional Rayleigh/Taylor unstable flow using direct numerical simulation data  

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

Data from a 1152X760X1280 direct numerical simulation (DNS) [N. J. Mueschke and O. Schilling, Phys. Fluids 21, 014106 (2009)] of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipation and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. These results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.

Schilling, Oleg [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mueschke, Nicholas J. [Texas A and M Univ., College Station, TX (United States)

2010-10-18T23:59:59.000Z

212

Selective large-eddy simulation of hypersonic flows. Procedure to activate the filtering in unresolved regions only  

E-Print Network [OSTI]

A new method for the localization of the regions where the turbulent fluctuations are unresolved is applied to the large-eddy simulation (LES) of a compressible turbulent jet with an initial Mach number equal to 5. The localization method used is called selective LES and is based on the exploitation of a scalar probe function f which represents the magnitude of the stretching-tilting term of the vorticity equation normalized with the enstrophy (Tordella et al. 2007). For a fully developed turbulent field of fluctuations, statistical analysis shows that the probability that f is larger than 2 is almost zero, and, for any given threshold, it is larger if the flow is under-resolved. By computing the spatial field of f in each instantaneous realization of the simulation it is possible to locate the regions where the magnitude of the normalized vortical stretching-tilting is anomalously high. The sub-grid model is then introduced into the governing equations in such regions only. The results of the selective LES s...

Tordella, D; Massaglia, S; Mignone, A

2012-01-01T23:59:59.000Z

213

Multiphase flow simulations of a moving fluidized bed regenerator in a carbon capture unit  

SciTech Connect (OSTI)

To accelerate the commercialization and deployment of carbon capture technologies, computational fuid dynamics (CFD)-based tools may be used to model and analyze the performance of carbon cap-ture devices. This work presents multiphase CFD-based ow simulations for the regenerator|a device responsible for extracting CO2 from CO2-loaded sorbent particles before the particles are recycled. The use of solid particle sorbents in this design is a departure from previously reported systems, where aque-ous sorbents are employed. Another new feature is the inclusion of a series of perforated plates along the regenerator height. The in uence of these plates on sorbent distribution is examined for varying sorbent holdup, uidizing gas velocity, and particle size. The residence time distribution of sorbents is also measured to classify the low regime as plug ow or well-mixed ow. The purpose of this work is to better understand the sorbent ow characteristics before reaction kinetics of CO2 desorption can be implemented.

Sarkar, Avik; Pan, Wenxiao; Suh, Dong-Myung; Huckaby, E. D.; Sun, Xin

2014-10-01T23:59:59.000Z

214

NUMERICAL FLOW AND TRANSPORT SIMULATIONS SUPPORTING THE SALTSTONE FACILITY PERFORMANCE ASSESSMENT  

SciTech Connect (OSTI)

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

215

[1] Mihalef et al, "Atrioventricular blood flow simulation based on patient-specific data," in Proceed-ings of FIMH 2009, 2009.  

E-Print Network [OSTI]

suffers a heart attack or any other heart abnormality, the way in which blood moves through the heart of abnormal hearts, including those that suf- fered from heart attacks or have blood clots. Run simulation specific computational flow modeling of the left heart via combination of magnetic resonance imaging

216

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...

Vijaykumar, Anand

2011-02-22T23:59:59.000Z

217

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 (OSTI)

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

218

DSMC and Navier-Stokes simulations are performed as part of a code validation effort for hypersonic flows.  

E-Print Network [OSTI]

for hypersonic flows. The flowfield examined herein is the Mach 11, laminar flow over a 25 deg - 55 deg blunted methods for hypersonic separated flows. Excellent agreement is found between the DSMC and Navier, and optimization of hypersonic flight systems, primarily due to the difficulties of repro- ducing high flight

Roy, Chris

219

Simulation of steady-state and transient sodium boiling experiments in a seven-pin bundle under flow rundown conditions by using BODYFIT-1FE code  

SciTech Connect (OSTI)

A seven-pin rod bundle under flow rundown conditions was simulated by using the computer code BODYFIT-1FE (BOunDarY-FITted Coordinate System - 1 phase, Fully-Elliptic). In this code, the complicated rod bundle configuration is first transformed into rectangular geometry with uniform meshes. The transformed governing equations for all the thermal-hydraulic variables are then solved. The results of the simulation are presented here. All the predicted values agree favorably with the measured data. 7 refs., 20 figs.

Chen, B.C.J.; Sha, W.T.

1981-01-01T23:59:59.000Z

220

Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system  

E-Print Network [OSTI]

DEALING WITH BIG CIRCULATION FLOW RATE, SMALL TEMPERATURE DIFFERENCE BASED ON VERIFIED DYNAMIC MODEL SIMULATIONS OF A HOT WATER DISTRICT HEATING SYSTEM Li Lian Zhong, Senior Sales Consultant, Danfoss Automatic Controls Management (Shanghai...) Co.,Ltd, Anshan, China ABSTRACT Dynamic models of an indirect hot water district heating system were developed based on the first principle of thermodynamics. The ideal model was verified by using measured operational data. The ideal...

Zhong, L.

2014-01-01T23:59:59.000Z

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.


221

Numerical simulation of the fluid flow and heat transfer processes during scavenging in a two-stroke engine under steady-state conditions  

SciTech Connect (OSTI)

A numerical simulation of the scavenging process in a two-stroke flat-piston model engine has been developed. Air enters the cylinder circumferentially, inducting a three-dimensional turbulent swirling flow. The problem was modeled as a steady-state axisymmetric flow through a cylinder with uniform wall temperature. The steady-state regime was simulated by assuming the piston head fixed at the bottom dead center. The calculation was performed employing the {kappa}-{epsilon} model of turbulence. A comparison of the results obtained for the flow field with available experimental data showed very good agreement, and a comparison with an available numerical solution revealed superior results. The effects of the Reynolds number, inlet port angles, and engine geometry on the flow and in-cylinder heat transfer characteristics were investigated. The Nusselt number substantially increases with larger Reynolds numbers and a smaller bore-to-stroke ratio. It is shown that the positioning of the exhaust value(s) is the main parameter to control the scavenging process.

Castro Gouveia, M. de; Reis Parise, J.A. dos; Nieckele, A.O. (Pontificia Univ. Catolica, Rio de Janeiro (Brazil))

1992-05-01T23:59:59.000Z

222

Global Evaluation of the ISBA-TRIP Continental Hydrological System. Part II: Uncertainties in River Routing Simulation Related to Flow  

E-Print Network [OSTI]

the entire globe. RRMs have been introduced into earth system models (ESMs) to convert the runoff simulated

Boyer, Edmond

223

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

SciTech Connect (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

224

Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor  

SciTech Connect (OSTI)

A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m{sup 3}/hr.

Polzin, Kurt A.; Godfroy, Thomas J. [NASA Marshall Space Flight Center Propulsion Research and Technology Applications Branch/ER24, MSFC, AL 35812 (United States)

2008-01-21T23:59:59.000Z

225

A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations  

E-Print Network [OSTI]

with ¢¡¤£¦¥§ ¨¡© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning management for the evaluation of the Yucca Mountain site as a repository for nuclear wastes. In this context of developing a 3D flow model of the Yucca Mountain site, involving computational grids of to blocks

Elmroth, Erik

226

A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat Flow Simulations  

E-Print Network [OSTI]

6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid of Energy's civilian nuclear waste management for the evaluation of the Yucca Mountain site as a repository is currently in charge of developing a 3D flow model of the Yucca Mountain site, involving computational grids

Elmroth, Erik

227

Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California  

SciTech Connect (OSTI)

Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35{degrees}N., long 115{degrees}W and lat 38{degrees}N., long 118{degrees}W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system.

D`Agnese, F.A.; Faunt, C.C.; Turner, A.K.; Hill, M.C.

1997-12-31T23:59:59.000Z

228

A one-way coupled, EulerLagrangian simulation of bubble coalescence in a turbulent pipe flow  

E-Print Network [OSTI]

modifies the speed of sound in the bubbly mixture, which has implications for marine acoustic signatures. Gas­liquid flow at microgravity conditions ­ I. Dispersed bubble and slug flow. Int. J. Multiphase- ical in many heat transfer problems where liquid water contacting a hot surface boils and the resulting

Mahesh, Krishnan

229

Researchers at Lancaster University are using the supercomputing capability of the Hartree Centre to accurately simulate the flow of  

E-Print Network [OSTI]

industry, there is great interest in in stabilising flows through oil reservoirs to enhance extraction. However, efficiently modelling oil flow in reservoirs can be complex and time consuming due reservoirs with the subsequent enhancement of oil extraction processes. www.stfc.ac.uk/hartree "Despite

Zharkova, Valentina V.

230

Numerical Investigations of Magnetohydrodynamic Hypersonic Flows.  

E-Print Network [OSTI]

??Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow are presented for both laminar and turbulent flow over a cylinder and flow entering a scramjet inlet. ANSYS (more)

Guarendi, Andrew N

2013-01-01T23:59:59.000Z

231

Computational fluid dynamics assessment: Volume 1, Computer simulations of the METC (Morgantown Energy Technology Center) entrained-flow gasifier: Final report  

SciTech Connect (OSTI)

An assessment of the theoretical and numerical aspects of the computer code, PCGC-2, is made; and the results of the application of this code to the Morgantown Energy Technology Center (METC) advanced gasification facility entrained-flow reactor, ''the gasifier,'' are presented. PCGC-2 is a code suitable for simulating pulverized coal combustion or gasification under axisymmetric (two-dimensional) flow conditions. The governing equations for the gas and particulate phase have been reviewed. The numerical procedure and the related programming difficulties have been elucidated. A single-particle model similar to the one used in PCGC-2 has been developed, programmed, and applied to some simple situations in order to gain insight to the physics of coal particle heat-up, devolatilization, and char oxidation processes. PCGC-2 was applied to the METC entrained-flow gasifier to study numerically the flash pyrolysis of coal, and gasification of coal with steam or carbon dioxide. The results from the simulations are compared with measurements. The gas and particle residence times, particle temperature, and mass component history were also calculated and the results were analyzed. The results provide useful information for understanding the fundamentals of coal gasification and for assessment of experimental results performed using the reactor considered. 69 refs., 35 figs., 23 tabs.

Celik, I.; Chattree, M.

1988-07-01T23:59:59.000Z

232

An approach for simulation of paraffin deposition in pipelines as a function of flow characteristics with a reference to Teesside oil pipeline  

SciTech Connect (OSTI)

Paraffin deposition is experienced in pipelines during transportation of oil when the oil temperature is cooled below its paraffin deposition temperature. The formed paraffin crystals in the bulk flow are believed to be transported by molecular, brownian diffusion and shear dispersion. Gravity settling mechanism in previous work in the authors` laboratory has been shown to contribute to the total paraffin deposition, however, to a lesser extent than the above mentioned mechanisms. The work done here demonstrates that the paraffin deposition by molecular diffusion mechanism is a dominant one. This is in agreement with other previous studies done on the paraffin deposition. In this study, however, experimental design was made to quantify this statement. The paraffin concentration gradient (dc/dr) is the driving force of the molecular diffusion mechanism (where r is the pipeline radius). In pipelines the cooling rate is one of many factors that affect the paraffin deposition profile. Equipment was designed to simulate the flow characteristics at pipeline pressure. A three dimensional model was developed for paraffin deposition rates at various flow regimes. The developed experimental approach and the designed equipment for simulating the pipeline conditions are presented in this paper.

Hamouda, A.A.; Davidsen, S.

1995-11-01T23:59:59.000Z

233

A shallow water model for the numerical simulation of overland flow on surfaces with ridges and furrows  

E-Print Network [OSTI]

induces problems at watershed scale for soil conservation (decrease of soil thickness by erosion, nutrient (drinking water) and sustainability of aquatic ecosystems (chemical pollution). These troubles can be prevented by watershed management. Improving watershed management in relationships with overland flow

234

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...

Haghshenas, Arash

2013-04-24T23:59:59.000Z

235

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

E-Print Network [OSTI]

of Electric Power Industry, Chiba, Japan FOTINI KATOPODES CHOW Department of Civil and Environmental to the choice of numerical simulation parameters than is typically needed for mean wind field predictions. Large-eddy simulation is used in a mesoscale setting, providing modeling advantages through the use of robust turbulence

Chow, Fotini Katopodes

236

IEEE PES WM Panel on Modeling, Simulation and Applications of FACTS Controllers in Angle and Voltage Stability Studies, Singapore, Jan. 2000 Power Flow and Transient Stability Models of FACTS Controllers  

E-Print Network [OSTI]

, the Static Syn- chronous Source Series Compensator SSSC, and the Uni edPower FlowController UPFC appropriateIEEE PES WM Panel on Modeling, Simulation and Applications of FACTS Controllers in Angle and Voltage Stability Studies, Singapore, Jan. 2000 Power Flow and Transient Stability Models of FACTS

Cañizares, Claudio A.

237

In this project, we deal with the simulation and the optimisation of flows when uncertainties exist in the models and/or the data. We only consider non intrusive methods so that existing CFD softwares  

E-Print Network [OSTI]

with the thermodynamical models for dense organic gas flows used in some energy production devices. It is knownSummary In this project, we deal with the simulation and the optimisation of flows when arising from the study of energy generators for renewable sources. The three task will be done in parallel

Abgrall, Rémi

238

Three-Dimensional Characteristics of Post-CHF Behaviour Within a Rod Bundle for Loss-of-Flow Simulation: Experimental and Three-Fluid Porous Media Numerical Analyses  

SciTech Connect (OSTI)

The investigation of three-dimensional transient propagations of dry-out fronts within a nuclear fuel rod bundle is performed, based on experimental and numerical simulations. The spreading of Critical Heat Flux (CHF) fronts across a bundle, caused by sudden decrease of coolant mass flow rate followed by delayed gradual decrease of power generation is predicted, and the locus of dry patches is shown. Simultaneous occurrence of CHF and re-wet multi-fronts in here-analysed flow transient has not been detected so obvious as in power transient, previously analysed. Due to a possible building of a vapour zone, the CHF front spatial propagation has to be carefully analysed in transient conditions. (authors)

Stosic, Zoran V. [Framatome ANP GmbH, PO Box 3220, Erlangen, 91050 (Germany); Stevanovic, Vladimir D. [University of Belgrade, Kraljice Marije 16, 11000 Belgrade, Serbia and Montenegro (Yugoslavia); Tadashi Iguchi [Japan Atomic Energy Research Institute, Tokai-mura 319-1195 (Japan)

2002-07-01T23:59:59.000Z

239

Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation  

SciTech Connect (OSTI)

The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

Perin, A.; Casas-Cubillos, J.; Pezzetti, M. [CERN, CH-1211 Geneva 23 (Switzerland); Almeida, M. [Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte (Brazil)

2014-01-29T23:59:59.000Z

240

Simulation of the influence high-frequency (2 MHz) capacitive gas discharge and magnetic field on the plasma sheath near a surface in hypersonic gas flow  

SciTech Connect (OSTI)

The plasma sheath near the surface of a hypersonic aircraft formed under associative ionization behind the shock front shields the transmission and reception of radio signals. Using two-dimensional kinetic particle-in-cell simulations, we consider the change in plasma-sheath parameters near a flat surface in a hypersonic flow under the action of electrical and magnetic fields. The combined action of a high-frequency 2-MHz capacitive discharge, a constant voltage, and a magnetic field on the plasma sheath allows the local electron density to be reduced manyfold.

Schweigert, I. V., E-mail: ischweig@itam.nsc.ru [Russian Academy of Sciences, Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch (Russian Federation)

2012-08-15T23:59:59.000Z

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

Numerical simulation of two-phase flow in discrete fractures using Rayleigh-Ritz finite element method  

E-Print Network [OSTI]

Spontaneous imbibition plays a very important role in the displacement mechanism of non-wetting fluid in naturally fractured reservoirs. We developed a new 2D two-phase finite element numerical model, as available commercial simulators cannot...

Kaul, Sandeep P.

2004-09-30T23:59:59.000Z

242

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

243

Towards practical implementation of computational solution of the Kinematic -wave Model for simulating traffic-flow scenarios  

E-Print Network [OSTI]

The Kinematic-wave model is one of the models proposed to simulate vehicular traffic. It has not received widespread use because of poor understanding of associated interface conditions and early use of incorrect numerical schemes used. This thesis...

Kumar, Nishant

2004-11-15T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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

245

Low Speed Virtual Wind Tunnel Simulation For Educational Studies In Introducing Computational Fluid Dynamics And Flow Visualization  

E-Print Network [OSTI]

............................................................................................................... 25 3.2.4. Starting FlowLab ...................................................................................................................... 26 3.2.5. Geometry Settings... OF THE PROGRAMMING....................................................................... 52 v List of Figures FIGURE 2.1 ? COST AND TIME RELATIONSHIP WITH RESPECT TO CFD AND WIND TUNNELS............................. 5 FIGURE 2.2 - BOEING 777 DESIGN...

Yang, Cher-Chiang

2008-05-05T23:59:59.000Z

246

Simulation of fluid flow mechanisms in high permeability zones (Super-K) in a giant naturally fractured carbonate reservoir  

E-Print Network [OSTI]

and fractures were treated as two systems. Reservoir management practices and decisions should be very carefully reviewed and executed in this dual continuum reservoir based on the results of this work. Studying this dual media flow behavior is vital for better...

Abu-Hassoun, Amer H.

2009-05-15T23:59:59.000Z

247

Development and verification of a numerical simulator to calculate the bottom hole flowing pressures in multiphase systems  

E-Print Network [OSTI]

the Middle East, but there were some wells located in offshore Louisiana. There was a wide range Of variation in the variables for each well, some of these were: flow rates, gas/oil ratios, total depths, tubing sizes, fluid Compositions, and water cuts...

Rasool, Syed Ahmed

1994-01-01T23:59:59.000Z

248

Numerical Simulation of Flow and Heat Transfer in Internal Multi-Pass Cooling Channel within Gas Turbine Blade  

E-Print Network [OSTI]

four-pass channel with two different inlet settings. The main flowing channel was rectangular channel (AR=2:1) with hydraulic diameter (Dh ) equals to 2/3 inch (16.9 mm). The first and fourth channel were set as different aspect ratio (AR=2:1; AR=1...

Chu, Hung-Chieh 1979-

2012-11-16T23:59:59.000Z

249

Using Stochastic Discounted Cash Flow and Real Option Monte Carlo Simulation to Analyse the Impacts of Contingent Taxes on  

E-Print Network [OSTI]

on the economics of their projects. This paper examines the valuation of a multi-phase copper-gold project to government, smelters and refineries, creditors and equity. Non-linear cash flows have a curved or `kinked of a copper-gold project. An analysis of the recent Mongolian windfall tax illustrates how tax changes affect

250

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanical Deformation/Fracture Generation Simulator  

Broader source: Energy.gov [DOE]

This research will develop a fully coupled, fully implicit approach for EGS stimulation and reservoir simulation. Solve all governing equations simultaneously in fully implicit way. Enable massively parallel performance and scalability. Apply state of the art nonlinear PDE solvers: Jacobian Free Newton Krylov (JFNK) method.

251

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

E-Print Network [OSTI]

The impact of climate, CO2, nitrogen deposition and land use change on simulated contemporary., 38, L08704, doi:10.1029/ 2011GL046773. 1. Introduction [2] Climate change and human activities and Fung [2008] found that climate and land use change play more important roles than the stomatal closure

Hoffman, Forrest M.

252

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.

253

USERS GUIDE of TOUGH2-EGS-MP: A Massively Parallel Simulator with Coupled Geomechanics for Fluid and Heat Flow in Enhanced Geothermal Systems VERSION 1.0  

SciTech Connect (OSTI)

TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.

Xiong, Yi [Colorado School of Mines; Fakcharoenphol, Perapon [Colorado School of Mines; Wang, Shihao [Colorado School of Mines; Winterfeld, Philip H. [Colorado School of Mines; Zhang, Keni [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines

2013-12-01T23:59:59.000Z

254

Multigrid and Krylov Solvers for Large Scale Finite Element Groundwater Flow Simulations on Distributed Memory Parallel Platforms  

SciTech Connect (OSTI)

In this report we present parallel solvers for large linear systems arising from the finite-element discretization of the three-dimensional steady-state groundwater flow problem. Our solvers are based on multigrid and Krylov subspace methods. The parallel implementation is based on a domain decomposition strategy with explicit message passing using NX and MPI libraries. We have tested our parallel implementations on the Intel Paragon XP/S 150 supercomputer using up to 1024 parallel processors and on other parallel platforms such as SGI/Power Challenge Array, Cray/SGI Origin 2000, Convex Exemplar SPP-1200, and IBM SP using up to 64 processors. We show that multigrid can be a scalable algorithm on distributed memory machines. We demonstrate the effectiveness of parallel multigrid based solvers by solving problems requiring more than 70 million nodes in less than a minute. This is more than 25 times faster than the diagonal preconditioned conjugate gradient method which is one of the more popular methods for large sparse linear systems. Our results also show that multigrid as a stand alone solver works best for problems with smooth coefficients, but for rough coefficients it is best used as a preconditioner for a Krylov subspace method such as the conjugate gradient method. We show that even for extremely heterogeneous systems the multigrid pre-conditioned conjugate gradient method is at least 10 times faster than the diagonally preconditioned conjugate gradient method.

Mahinthakumar, K.

1997-01-01T23:59:59.000Z

255

A Simulator with Numerical Upscaling for the Analysis of Coupled Multiphase Flow and Geomechanics in Heterogeneous and Deformable Porous and Fractured Media  

E-Print Network [OSTI]

multi-dimensional rock deformation. A coupled flow and geomechanics model considers flow physics and rock physics simultaneously by cou-pling different types of partial differential equations through primary variables. A number of coupled flow...

Yang, Daegil

2013-07-15T23:59:59.000Z

256

Technology Assistance Program | Partnerships | ORNL  

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

Assistance Program SHARE Technology Assistance Program Electronics Research Assistance is available for small business licensees of ORNL technologies to leverage ORNL's expertise...

257

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.

258

Methane-assisted combustion synthesis of nanocomposite tin dioxide materials  

E-Print Network [OSTI]

Methane-assisted combustion synthesis of nanocomposite tin dioxide materials S.D. Bakrania *, C and flow conditions using methane as a supplemental fuel. The experiments were carried out at atmospheric-phase precursor for metal additives. In the methane-assisted (MA) system, the inert carrier gas was replaced

Wooldridge, Margaret S.

259

Cooling Flows or Heating Flows?  

E-Print Network [OSTI]

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.

James Binney

2003-10-08T23:59:59.000Z

260

ARC-HEATED GAS FLOW EXPERIMENTS FOR HYPERSONIC PROPULSION  

E-Print Network [OSTI]

was extensively developed for the purpose of eventually performing experiments simulating scramjet engine flow

Texas at Arlington, University of

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

E-Print Network 3.0 - assist device lvad Sample Search Results  

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

2006 Society for Industrial and Applied Mathematics Vol. 67, No. 1, pp. 164193 Summary: -LG-RA-08 Modeling of Pulsatile Ventricular Assist Devices Simulation of the interaction...

262

E-Print Network 3.0 - assisted laparoscopic radical Sample Search...  

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

TRAINING Bricelis... , a virtual reality laparoscopic surgery simulator that includes a brand new educational component, to assist... together, makes of LAPAROS an advanced...

263

Assistance Focus: Africa (Brochure)  

SciTech Connect (OSTI)

The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

Not Available

2014-12-01T23:59:59.000Z

264

DOE Technical Assistance Program  

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

support - Design assistance - Commissioning * Keeps business processes simple * Leverages green building initiatives 26 | TAP Webinar eere.energy.gov 26 Typical Efficiency Measures...

265

DOE Technical Assistance Program  

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

Provide SEP & EECBG recipients with resources needed to swiftly implement successful and sustainable clean energy programs. Objectives: To provide proactive assistance, technical...

266

Radiological Assistance Program  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

To establish Department of Energy (DOE) policy, procedures, authorities, and responsibilities for its Radiological Assistance Program. Canceled by DOE O 153.1.

1992-04-10T23:59:59.000Z

267

DOE Technical Assistance Program  

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

eere.energy.gov What is TAP? DOE's Technical Assistance Program (TAP) supports the Energy Efficiency and Conservation Block Grant Program (EECBG), the State Energy Program...

268

Brownfield Assistance Program (Delaware)  

Broader source: Energy.gov [DOE]

The Brownfield Assistance Program, administrated by the Delaware Economic Development Office (DEDO) and funded from Delaware Strategic Fund, provides matching grants to owners and developers to...

269

Monica Sasse Executive Assistant  

E-Print Network [OSTI]

Swenson, Natalie Bryant, Allie Rowe Student Recruiting Sadie Johnson, Susie DeMoss Deb Dewall Assistant Institute Diane Meyer Pre-award Services Engineering Research Institute Engineering '("#)*(+#,)!-$.)/010

Vaswani, Namrata

270

Employee and Family Assistance  

E-Print Network [OSTI]

Human Solutions is available to help you anytime of the day or week, in English and in French. Toll free English: 1-800-663-1142 Toll free French: 1-866-398-9505 TTY (Hearing assistance) 1 Assistance Program (EFAP) provides confidential, professional counselling for a broad range of personal

Seldin, Jonathan P.

271

Improving parameter estimation and water table depth simulation in a land surface model using GRACE water storage and estimated base flow data  

E-Print Network [OSTI]

40, doi:10.1175/2008JHM993.1. Szilagyi, J. (2004), Heuristicsimulations of base flow [Szilagyi, 2004]. Although the

Lo, Min-Hui; Famiglietti, James S; Yeh, P. J.-F.; Syed, T. H

2010-01-01T23:59:59.000Z

272

TMVOC, simulator for multiple volatile organic chemicals  

SciTech Connect (OSTI)

TMVOC is a numerical simulator for three-phase non-isothermal flow of water, soil gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. It is an extension of the TOUGH2 general-purpose simulation program developed at the Lawrence Berkeley National Laboratory. TMVOC is designed for applications to contamination problems that involve hydrocarbon fuel or organic solvent spills in saturated and unsaturated zones. It can model contaminant behavior under ''natural'' environmental conditions, as well as for engineered systems, such as soil vapor extraction, groundwater pumping, or steam-assisted source remediation. TMVOC is upwards compatible with T2VOC (Falta et al., 1995) and can be initialized from T2VOC-style initial conditions. The main enhancements in TMVOC relative to T2VOC are as follows: a multicomponent mixture of volatile organic chemicals can be modeled; any and all combinations of the three phases water-oil-gas are treated; several non-condensible gases may be present; diffusion is treated in all phases in a manner that is fully coupled with phase partitioning. This paper gives a brief summary of the methodology used in TMVOC as well as highlighting some implementation issues. Simulation of a NAPL spill and subsequent remediation is discussed for a 2-D vertical section of a saturated-unsaturated flow problem.

Pruess, Karsten; Battistelli, Alfredo

2003-03-25T23:59:59.000Z

273

Mexico Small Business Assistance fest  

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

celebrate success at New Mexico Small Business Assistance fest April 4, 2011 LOS ALAMOS, New Mexico, April 4, 2011-The New Mexico Small Business Assistance (NMSBA) program is...

274

Weatherization Assistance Program Technical Assistance Center  

SciTech Connect (OSTI)

The following is a synopsis of the major achievements attributed to the operation of the Weatherization Assistance Program Technical Assistance Center (WAPTAC) by the National Association for State Community Services Programs (NASCSP). During the past five years, the WAPTAC has developed into the premier source for information related to operating the Weatherization Assistance Program (WAP) at the state and local levels. The services provide through WAPTAC include both virtual technical support as well as hands-on training and instruction in classroom and in the field. The WAPTAC achieved several important milestones during its operation including the establishment of a national Weatherization Day now celebrated in most states, the implementation of a comprehensive Public Information Campaign (PIC) to raise the awareness of the Program among policy makers and the public, the training of more than 150 new state managers and staff as they assume their duties in state offices around the country, and the creation and support of a major virtual information source on the Internet being accessed by thousands of staff each month. The Weatherization Assistance Program Technical Assistance Center serves the Department of Energy's (DOE) Office of Weatherization and Intergovernmental Program as a valuable training and technical assistance resource for the network of 54 direct state grantees (50 states, District of Columbia and three Native American tribes) and the network of 900 local subgrantees (comprised of community action agencies, units of local government, and other non-profit organizations). The services provided through WAPTAC focus on standardizing and improving the daily management of the WAP. Staff continually identify policies changes and best practices to help the network improve its effectiveness and enhance the benefits of the Program for the customers who receive service and the federal and private investors. The operations of WAPTAC are separated into six distinct areas: (1) Orientation for New WAP State Directors and Staff; (2) Pollution Occurrence Insurance Project; (3) Public Information Campaign; (4) State Management Training Project; (5) System for Integrating and Reviewing Technologies and Techniques; and (6) WAPTAC Services.

Robert Adams

2009-01-07T23:59:59.000Z

275

Chris Sexton Assistant Director  

E-Print Network [OSTI]

Peter Armstrong Infrastructure Stewart Harris Application Support Martin Rapier Network Group Unix Group Barraclough Business Support Peter Armstrong Performance Space Reuben Grocock Assistant Director Business Julia Harrison Programme and Projects Unit Pablo Stern Reporting & Management Information Phillip

Martin, Stephen John

276

Assisting Difficult Calving  

E-Print Network [OSTI]

Calving difficulty is frequently caused by disproportionate size--the calf is too big for the birth canal. This publication discusses the stages of labor, how to assist in delivery and what to do after the delivery of a calf....

Faries Jr., Floron C.

2006-12-20T23:59:59.000Z

277

FINANCIAL ASSISTANT Binghamton University  

E-Print Network [OSTI]

of purchases, assigning general ledger accounts to employee labor records as well as purchase orders and workFINANCIAL ASSISTANT Binghamton University Physical Facilities - Finance & Resources Job Description purchasing functionality, accounts payable and receivable functionality and our employee labor distribution

Suzuki, Masatsugu

278

9003: Biorefinery Assistance Program  

Broader source: Energy.gov [DOE]

Breakout Session 1DBuilding Market Confidence and Understanding I: Integrated Biorefinery (Lessons Learned and Best Practices) 9003: Biorefinery Assistance Program Chris Cassidy, National Business Renewable Energy Advisor, U.S. Department of Agriculture

279

An Efficient, Semi-implicit Pressure-based Scheme Employing a High-resolution Finitie Element Method for Simulating Transient and Steady, Inviscid and Viscous, Compressible Flows on Unstructured Grids  

SciTech Connect (OSTI)

A new semi-implicit pressure-based Computational Fluid Dynamics (CFD) scheme for simulating a wide range of transient and steady, inviscid and viscous compressible flow on unstructured finite elements is presented here. This new CFD scheme, termed the PCICEFEM (Pressure-Corrected ICE-Finite Element Method) scheme, is composed of three computational phases, an explicit predictor, an elliptic pressure Poisson solution, and a semiimplicit pressure-correction of the flow variables. The PCICE-FEM scheme is capable of second-order temporal accuracy by incorporating a combination of a time-weighted form of the two-step Taylor-Galerkin Finite Element Method scheme as an explicit predictor for the balance of momentum equations and the finite element form of a time-weighted trapezoid rule method for the semi-implicit form of the governing hydrodynamic equations. Second-order spatial accuracy is accomplished by linear unstructured finite element discretization. The PCICE-FEM scheme employs Flux-Corrected Transport as a high-resolution filter for shock capturing. The scheme is capable of simulating flows from the nearly incompressible to the high supersonic flow regimes. The PCICE-FEM scheme represents an advancement in mass-momentum coupled, pressurebased schemes. The governing hydrodynamic equations for this scheme are the conservative form of the balance of momentum equations (Navier-Stokes), mass conservation equation, and total energy equation. An operator splitting process is performed along explicit and implicit operators of the semi-implicit governing equations to render the PCICE-FEM scheme in the class of predictor-corrector schemes. The complete set of semi-implicit governing equations in the PCICE-FEM scheme are cast in this form, an explicit predictor phase and a semi-implicit pressure-correction phase with the elliptic pressure Poisson solution coupling the predictor-corrector phases. The result of this predictor-corrector formulation is that the pressure Poisson equation in the PCICE-FEM scheme is provided with sufficient internal energy information to avoid iteration. The ability of the PCICE-FEM scheme to accurately and efficiently simulate a wide variety of inviscid and viscous compressible flows is demonstrated here.

Richard C. Martineau; Ray A. Berry

2003-04-01T23:59:59.000Z

280

Measurement of two-phase flow at the core/upper plenum interface for a PWR geometry under simulated reflood conditions  

SciTech Connect (OSTI)

The Instrument Development Loop (IDL) Program is part of the International 2D/3D Refill and Reflood Experimental and Analytical Research Program. Among the objectives of the International Program are: the study of the steam binding effect during reflood flow distribution (chimney effect) in a heated core; and the study of flow hydrodynamics in the core, downcomer and upper plenum during refill and reflood. Three experimental facilities were used in these studies: a one-bundle air/water loop, a three-bundle air/water loop, and a one-bundle steam/water loop. The loops represent full-scale vertical sections of the UPTF, extending from spray nozzles to the top of the upper plenum and including a short length of dummy fuel rods, upper end boxes, core support plate and control rod guide tubes. Three flow regimes were identified and studied: (1) all liquid down; (2) countercurrent flow in which gas (or vapor) goes up and liquid goes both up and down; and (3) cocurrent flow in which both gas (or vapor) and liquid go up.

Thomas, D.G.; Combs, S.K.

1983-08-01T23:59:59.000Z

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.


281

Technical Assistance to Developers  

SciTech Connect (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

282

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

SciTech Connect (OSTI)

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 Companys 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

283

Flow and transport simulations using T2CG1, a package of conjugate gradient solvers for the TOUGH2 family of codes  

SciTech Connect (OSTI)

This report discusses the details of modifications made to the TOUGH2 family of codes to complement its direct solver which significantly increases the size of problems solved by the TOUGH2 code. With this modification, the TOUGH2 system is being tested in multiphase, multicomponent fluid and heat flow problems related to vadose zone hydrology, nuclear waste disposal, and environmental remediation.

Moridis, G.; Pruess, K.

1995-04-01T23:59:59.000Z

284

Previous Technical Assistance | Department of Energy  

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

Technical assistance provided to WGAWIEB by the Electricity Market Studies Group of LBNL and The Regulatory Assistance Project (RAP); and More limited technical assistance...

285

Anantha Aiyyer Assistant Professor  

E-Print Network [OSTI]

radiant energy over earth's surface Graphics source: Georgia Tech. Univ. 12 Solar energy received at any or rainfall amount is broken. Thus, even in a relatively cold climate, we can expect a heat wave or a record4/13/2011 1 Anantha Aiyyer Assistant Professor Marine, Earth and Atmospheric Sciences 1 Climate

Parker, Matthew D. Brown

286

Office of Security Assistance  

Broader source: Energy.gov [DOE]

The Office of Security Assistance manages the Technology Deployment Program to improve the security posture of the Department of Energy and the protection of its assets and facilities through the deployment of new safeguards and security technologies and development of advanced technologies that reduce operating costs, save protective force lives, and improve security effectiveness.

287

John Wright Assistant Professor  

E-Print Network [OSTI]

John Wright Assistant Professor Department of Electrical Engineering Columbia University Zhang and John Wright, "Efficient Point-to-Subspace Query with Application to Robust Face Recognition", submitted to SIAM Journal on Imaging Science, 2013. John Wright, Arvind Ganesh, Kerui Min and Yi Ma

Shepard, Kenneth

288

Medical Robots Surgical Assistants  

E-Print Network [OSTI]

1 Medical Robots Surgical Assistants Efficacy of Procedure Accuracy Longevity Invasiveness Augment human capabilities Enabling new procedures Time under anaesthetic #12;2 Surgical Robots) Sensei (Hansen Medical) Autonomous Surgical Robots Robodoc.com #12;3 Guided Surgical Robots Makosurgical

Pulfrey, David L.

289

About Technical Assistance  

Broader source: Energy.gov [DOE]

As technologies proceed along the development pipeline, most face major hurdles as they attempt to enter commercial markets. Our Technical Assistance program helps lower a range of institutional barriers to prepare innovative, energy-efficient technologies and energy management systems for full commercial deployment. These projects and activities address barriers that are not technical, Technology Readiness Level 9.

290

Electrocapturing flow cell  

DOE Patents [OSTI]

A flow cell for electrophoretically-assisted capturing analytes from a flow. The flow cell includes a specimen chamber, a first membrane, a second membrane, a first electrode chamber, and a second electrode chamber. The specimen chamber may have a sample inlet and a sample outlet. A first portion of the first membrane may be coupled to a first portion of the specimen chamber. A first portion of the second membrane may be coupled to a second portion of the specimen chamber. The first electrode chamber may be configured to accept a charge. A portion of the first electrode chamber may be coupled to a second portion of the first membrane. A second electrode chamber may be configured to accept an opposite charge. A portion of the second electrode chamber may be coupled to a second portion of the second membrane.

Morozov, Victor (Manassas, VA)

2011-04-05T23:59:59.000Z

291

Electromagnetically Induced Flows Michiel de Reus  

E-Print Network [OSTI]

Electromagnetically Induced Flows in Water Michiel de Reus 8 maart 2013 () Electromagnetically Conclusion and future research () Electromagnetically Induced Flows 2 / 56 #12;1 Introduction 2 Maxwell Navier Stokes equations 5 Simulations 6 Conclusion and future research () Electromagnetically Induced

Vuik, Kees

292

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]

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...

D'Sousa, Cedric Benedict

1997-01-01T23:59:59.000Z

293

Cotton flow  

E-Print Network [OSTI]

Using the conformally invariant Cotton tensor, we define a geometric flow, the "Cotton flow", which is exclusive to three dimensions. This flow tends to evolve the initial metrics into conformally flat ones, and is somewhat orthogonal to the Yamabe flow, the latter being a flow within a conformal class. We define an entropy functional, and study the flow of nine homogeneous spaces both numerically and analytically. In particular, we show that the arbitrarily deformed homogeneous 3-sphere flows into the round 3-sphere. Two of the nine homogeneous geometries, which are degenerated by the Ricci flow, are left intact by the Cotton flow.

Ali Ulas Ozgur Kisisel; Ozgur Sarioglu; Bayram Tekin

2008-06-17T23:59:59.000Z

294

Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs  

Broader source: Energy.gov [DOE]

Project objectives: Improve image resolution for microseismicimaging and time-lapse active seismic imaging; Enhance the prediction of fluid flow and temperature distributions and stress changes by coupling fracture flow simulations with reservoir flow simulations; and integrating imaging into modeling.

295

Carbon Tetrachloride Flow and Transport in the Subsurface of the 216-Z-18 Crib and 216-Z-1A Tile Field at the Hanford Site: Multifluid Flow Simulations and Conceptual Model Update  

SciTech Connect (OSTI)

Carbon tetrachloride (CT) was discharged to the 216-Z-9, Z-1A, and Z-18 waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the conceptual model of how CT is distributed in the Hanford 200 West Area subsurface through use of numerical flow and transport modeling. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy.

Oostrom, Mart; Rockhold, Mark L.; Thorne, Paul D.; Last, George V.; Truex, Michael J.

2006-10-31T23:59:59.000Z

296

Laser-assisted electrochemistry  

SciTech Connect (OSTI)

The effect of laser irradiation on electrodeposition processes has been investigated. These studies demonstrated that the addition of laser irradiation to an electroplating process can dramatically enhance plating rates and current efficiencies, as well as improve the morphology of the resultant electrodeposit. During the course of these investigations, the mechanism for the laser enhancement of electrodeposition processes was determined. Experimental evidence was obtained to show that laser irradiation of the substrate results in increased metal ion concentrations at the surface of the electrode due to a laser-induced Soret effect. The laser-induced Soret effect has important implications for laser-assisted electrochemical processing. The increase in the surface concentration of ions allows efficient electrodeposition from dilute solutions. As such, laser- assisted electrodeposition may develop into an environmentally conscious manufacturing process by reducing waste and limiting worker exposure to toxic chemicals.

Glenn, D.F.

1995-05-01T23:59:59.000Z

297

Weatherization Assistance Program: Spurring Innovation, Increasing...  

Energy Savers [EERE]

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

298

Energy Department Announces Technical Assistance Opportunity...  

Energy Savers [EERE]

Announces Technical Assistance Opportunity for Tribal Clean Energy Deployment Energy Department Announces Technical Assistance Opportunity for Tribal Clean Energy Deployment...

299

Electrically-Assisted Diesel Particulate Filter Regeneration...  

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

More Documents & Publications Substrate Studies of an Electrically-Assisted Diesel Particulate Filter Electrically-Assisted Diesel Particulate Filter Regeneration...

300

Weatherization Assistance Program  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment of Dept.| DepartmentVolvoWaterWeatherization Assistance Program

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

Fluid Flow Modeling in Fractures  

E-Print Network [OSTI]

In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...

Sarkar, Sudipta

2004-01-01T23:59:59.000Z

302

Lagrangian methods for ballistic impact simulations/  

E-Print Network [OSTI]

This thesis explores various Lagrangian methods for simulating ballistic impact with the ultimate goal of finding a universal, robust and scalable computational framework to assist in the design of armor systems. An overview ...

Tupek, Michael Ronne

2010-01-01T23:59:59.000Z

303

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Nanophoton Raman 11 Raman Spectroscopy $150 $175 Newport Solar Simulator Solar Simulator $150 $175 Nicolet $175 CM Furnace Furnace $65 $120 CNT Furnace Furnace $65 $120 Desert Cryo Probe Station Probe Station will be added depending on your funding instrument or agreement. #12;Lead Furnace Furnace $65 $120 Lindberg 1

Braun, Paul

304

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

$175 Newport Solar Simulator Solar Simulator $120 $175 Nicolet Nexus 670 FTIR Fourier Transform $175 CM Furnace Furnace $65 $120 CNT Furnace Furnace $65 $120 E-beam Evaporator 1 Electron Beam Point Probe Four point probe $0 $175 Lead Furnace Furnace $65 $120 Laser and Spectroscopy Facility Micro

Braun, Paul

305

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Newport Solar Simulator Solar Simulator $20 $50 Nicolet Nexus 670 FTIR Fourier Transform Infrared Deposition $20 $50 Ball Bonder Ball Bonder $20 $50 Cleanroom Cleanroom $20 $50 CM Furnace Furnace $15 $45 CNT Furnace Furnace $15 $45 E-beam Evaporator 1 Electron Beam Evaporation $20 $50 E-beam Evaporator 2 Electron

Braun, Paul

306

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Nanophoton Raman 11 Raman Spectroscopy $12 $37 Newport Solar Simulator Solar Simulator $12 $37 Nicolet Nexus Layer Deposition $70 $115 Ball Bonder Ball Bonder $70 $115 Cleanroom Cleanroom $70 $115 CM Furnace Furnace $30 $75 CNT Furnace Furnace $30 $75 Desert Cryo Probe Station Probe Station $70 $115 E

Braun, Paul

307

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Nanophoton Raman 11 Raman Spectroscopy $12 $37 Newport Solar Simulator Solar Simulator $12 $37 Nicolet Nexus Cleanroom Cleanroom $13 $38 CM Furnace Furnace $5 $30 CNT Furnace Furnace $5 $30 Desert Cryo Probe Station Facility Micro & Nano-Fabrication Facility #12;Jandel 4 Point Probe Four point probe $0 $38 Lead Furnace

Braun, Paul

308

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Nanophoton Raman 11 Raman Spectroscopy $12 $37 Newport Solar Simulator Solar Simulator $12 $37 Nicolet Nexus Deposition $20 $50 Ball Bonder Ball Bonder $20 $50 Cleanroom Cleanroom $20 $50 CM Furnace Furnace $15 $45 CNT Furnace Furnace $15 $45 Desert Cryo Probe Station Probe Station $20 $50 E-beam Evaporator 1 Electron Beam

Braun, Paul

309

Instrument Technique Staff Assisted &  

E-Print Network [OSTI]

Newport Solar Simulator Solar Simulator $70 $115 Nicolet Nexus 670 FTIR Fourier Transform Infrared CM Furnace Furnace $30 $75 CNT Furnace Furnace $30 $75 E-beam Evaporator 1 Electron Beam Evaporation point probe $0 $115 Lead Furnace Furnace $30 $75 Laser and Spectroscopy Facility Micro & Nano

Braun, Paul

310

In Vitro Evaluation of Multiobjective Hemodynamic Control of a Heart-Assist Pump  

E-Print Network [OSTI]

In Vitro Evaluation of Multiobjective Hemodynamic Control of a Heart-Assist Pump KWAN-WOONG GWAK§ Ventricular assist devices now clinically used for treatment of end-stage heart failure require responsive simulator using a HeartQuest centrifugal blood pump (CF4b, MedQuest Products, Salt Lake City, UT). To avoid

Paden, Brad

311

Non-thermal plasma-assisted NOx reduction over Na-Y zeolites...  

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

investigated in the non-thermal plasma assisted NOx reduction reaction using a simulated diesel engine exhaust gas mixture. The acid sites were formed by NH4+ ion exchange and...

312

Improved Steam Assisted Gravity Drainage (SAGD) Performance with Solvent as Steam Additive  

E-Print Network [OSTI]

Steam Assisted Gravity Drainage (SAGD) is used widely as a thermal recovery technique in Canada to produce a very viscous bitumen formation. The main research objectives of this simulation and experimental study are to investigate oil recovery...

Li, Weiqiang

2011-02-22T23:59:59.000Z

313

Impact assisted segmented cutterhead  

DOE Patents [OSTI]

An impact assisted segmented cutterhead device is provided for cutting various surfaces from coal to granite. The device comprises a plurality of cutting bit segments deployed in side by side relationship to form a continuous cutting face and a plurality of impactors individually associated with respective cutting bit segments. An impactor rod of each impactor connects that impactor to the corresponding cutting bit segment. A plurality of shock mounts dampening the vibration from the associated impactor. Mounting brackets are used in mounting the cutterhead to a base machine.

Morrell, Roger J. (Bloomington, MN); Larson, David A. (Minneapolis, MN); Ruzzi, Peter L. (Eagan, MN)

1992-01-01T23:59:59.000Z

314

Obtaining Disaster Assistance  

E-Print Network [OSTI]

? call TTY: 1-800-462-7585). You also may apply online at www.fema.gov (by clicking on ?Online Individual As- sistance Center?). FEMA does not accept applications through the mail; nor can they be completed at Disaster Recovery Centers (unless a Center...). If FEMA determines you are not eligible for assistance, you will receive a letter explaining why you were denied and how to appeal. Appeals must be made in writing and mailed within 60 days of FEMA?s decision. If you have insurance, you should contact...

Cavanagh, Joyce

2008-09-24T23:59:59.000Z

315

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

SciTech Connect (OSTI)

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

316

Expert assistants for design  

SciTech Connect (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

317

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

E-Print Network [OSTI]

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

Hoenninger, Corbett Reed

2001-01-01T23:59:59.000Z

318

Numerical simulation of ground-water flow in the Culebra dolomite at the Waste Isolation Pilot Plant (WIPP) site: Second interim report  

SciTech Connect (OSTI)

This hydrogeologic modeling study has been performed as part of the regional hydrologic characterization of the Waste Isolation Pilot Plant (WIPP) Site in southeastern New Mexico. The study resulted in an estimation of the transmissivity distrubution, hydraulic potentials, flow field, and fluid densities in the Culebra Dolomite Member of the Permian Rustler Formation at the WIPP site. The three-dimensional finite-difference code SWIFT-II was employed for the numerical modeling, using variable-fluid-density and a single-porosity formulation. The modeled area includes and extends beyond the WIPP controlled zone (Zone 3). The work performed consisted of modeling the hydrogeology of the Culebra using two approaches: (1) steady-state modeling to develop the best estimate of the undisturbed head distribution, i.e., of the situation before sinking if the WIPP shafts, which began in 1981; and (2) superimposed transient modeling of local hydrologic responses to excavation of the three WIPP shafts at the center of the WIPP site, as well as to various well tests. Boundary conditions (prescribed constant fluid pressures and densities) were estimated using hydraulic-head and fluid-density data obtained from about 40 wells at and near the WIPP site. The transient modeling used the calculated steady-state freshwater heads as initial conditions. 107 refs., 112 figs., 22 tabs.

LaVenue, A.M.; Haug, A.; Kelley, V.A.

1988-03-01T23:59:59.000Z

319

Transportation Economic Assistance Program (Wisconsin)  

Broader source: Energy.gov [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...

320

DOE and NREL Technical Assistance  

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

assistance to Greensburg, Kansas, in the following areas. MASTER PLAN FOR REBUILDING GREEN * Completed detailed studies on renewable energy sources, cost-effective energy...

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

New Mexico Small Business Assistance  

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

May 31, 2012 Program of Los Alamos, Sandia national laboratories LOS ALAMOS, NEW MEXICO, May 31, 2012-The New Mexico Small Business Assistance (NMSBA) program, a...

322

CFD analysis of laminar oscillating flows  

SciTech Connect (OSTI)

This paper describes a numerical simulations of oscillating flow in a constricted duct and compares the results with experimental and theoretical data. The numerical simulations were performed using the computational fluid dynamics (CFD) code CFX4.2. The numerical model simulates an experimental oscillating flow facility that was designed to test the properties and characteristics of oscillating flow in tapered ducts, also known as jet pumps. Jet pumps are useful devices in thermoacoustic machinery because they produce a secondary pressure that can counteract an unwanted effect called streaming, and significantly enhance engine efficiency. The simulations revealed that CFX could accurately model velocity, shear stress and pressure variations in laminar oscillating flow. The numerical results were compared to experimental data and theoretical predictions with varying success. The least accurate numerical results were obtained when laminar flow approached transition to turbulent flow.

Booten, C. W. Charles W.); Konecni, S. (Snezana); Smith, B. L. (Barton L.); Martin, R. A. (Richard A.)

2001-01-01T23:59:59.000Z

323

Strategy for quantum algorithm design assisted by machine learning  

E-Print Network [OSTI]

We propose a method for quantum algorithm design assisted by machine learning. The method uses a quantum-classical hybrid simulator, where a "quantum student" is being taught by a "classical teacher." In other words, in our method, the learning system is supposed to evolve into a quantum algorithm for a given problem assisted by classical main-feedback system. Our method is applicable to design quantum oracle-based algorithm. As a case study, we chose an oracle decision problem, called a Deutsch-Jozsa problem. We showed by using Monte-Carlo simulations that our simulator can faithfully learn quantum algorithm to solve the problem for given oracle. Remarkably, learning time is proportional to the square root of the total number of parameters instead of the exponential dependance found in the classical machine learning based method.

Jeongho Bang; Junghee Ryu; Seokwon Yoo; Marcin Pawlowski; Jinhyoung Lee

2014-07-17T23:59:59.000Z

324

Mathematical and experimental modelling of heat pump assisted microwave drying  

SciTech Connect (OSTI)

Drying is one of the most energy intensive operations in industry and agriculture. In the quest to increase drying efficiency and product quality, new technologies and methods are constantly being sought. Of these technologies, heat pump assisted drying and microwave drying have proved to be the most promising contenders. In order to achieve a better understanding and provide a computer design tool for heat pump assisted convective and microwave drying, both mathematical modelling and experimental investigations of heat pump assisted microwave dryers have been undertaken in this study. A mathematical model has been developed to predict the steady-state performance of a heat pump assisted continuous microwave dryer, with emphasis on the simulation of heat and mass transfer processes in the evaporator and drying chamber. The model is intend to serve as a design tool in the study of heat pump dryers. To achieve the optimum design, the influences of the key design and operating parameters, as well as the comparison of different drying configurations, have been examined. Based on investigation results, several methods have been proposed to improve the performance of heat pump assisted microwave drying, such as the use of a recuperator. To validate the above mathematical model, extensive drying tests using foam rubber as the test material have been conducted on a prototype heat pump assisted microwave dryer. The prototype heat pump input power was 5 kW with a maximum microwave input power of 10 kW. The experimental performance data confirmed the veracity of the simulation model. The experimental results on drying test materials indicate that with careful design heat pump assisted microwave drying is comparable to convective drying in energy consumption while with a much higher drying speed.

Xiguo Jia (Univ. of Queensland (Australia))

1993-01-01T23:59:59.000Z

325

Steady-state domain wall motion driven by adiabatic spin-transfer torque with assistance of microwave field  

SciTech Connect (OSTI)

We have studied the current-induced displacement of a 180 Bloch wall by means of micromagnetic simulation and analytical approach. It is found that the adiabatic spin-transfer torque can sustain a steady-state domain wall (DW) motion in the direction opposite to that of the electron flow without Walker Breakdown when a transverse microwave field is applied. This kind of motion is very sensitive to the microwave frequency and can be resonantly enhanced by exciting the domain wall thickness oscillation mode. A one-dimensional analytical model was established to account for the microwave-assisted wall motion. These findings may be helpful for reducing the critical spin-polarized current density and designing DW-based spintronic devices.

Wang, Xi-guang; Guo, Guang-hua, E-mail: guogh@mail.csu.edu.cn; Nie, Yao-zhuang; Xia, Qing-lin; Tang, Wei [School of Physics and Electronics, Central South University, Changsha 410083 (China)] [School of Physics and Electronics, Central South University, Changsha 410083 (China); Wang, D. [Department of Physics, National University of Defense Technology, Changsha 410073 (China)] [Department of Physics, National University of Defense Technology, Changsha 410073 (China); Zeng, Zhong-ming [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China)] [Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123 (China)

2013-12-23T23:59:59.000Z

326

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

327

Status of the ground water flow model for the UMTRA Project, Shiprock, New Mexico, site  

SciTech Connect (OSTI)

A two-dimensional numerical model was constructed for the alluvial aquifer in the area of the Uranium Mill Tailings Remedial Action (UMTRA) Project Shiprock, New Mexico, site. This model was used to investigate the effects of various hydrologic parameters on the evolution of the ground water flow field. Results of the model are useful for defining uncertainties in the site conceptual model and suggesting data collection efforts to reduce these uncertainties. The computer code MODFLOW was used to simulate the two-dimensional flow of ground water in the alluvium. The escarpment was represented as a no-flow boundary. The San Juan River was represented with the MODFLOW river package. A uniform hydraulic conductivity distribution with the value estimated by the UMTRA Project Technical Assistance Contractor (TAC) and a uniform recharge distribution was used. Infiltration from the flowing artesian well was represented using the well package. The ground water flow model was calibrated to ground water levels observed in April 1993. Inspection of hydrographs shows that these levels are representative of typical conditions at the site.

Not Available

1995-01-01T23:59:59.000Z

328

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and...

329

Reservoir management using streamline simulation  

E-Print Network [OSTI]

of information and sparsity of data. Quantifying this uncertainty in terms of reservoir performance forecast poses a major reservoir management challenge. One solution to this problem is flow simulation of a large number of these plausible reservoir descriptions...

Choudhary, Manoj Kumar

2000-01-01T23:59:59.000Z

330

GRADUATE COLLEGE TERMINATION OF GRADUATE ASSISTANT  

E-Print Network [OSTI]

GRADUATE COLLEGE TERMINATION OF GRADUATE ASSISTANT Policy Information & Directions for GA Termination 1. Once appointed, graduate assistants may not have their tuition/fees revoked standards, the Termination of Graduate Assistant form may be used to terminate a GA appointment

Cho, Hokwon

331

Help Desk Assistance | Department of Energy  

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

Online Learning Catalog Help Desk Assistance Help Desk Assistance Welcome to HelpDesk Assistance Online at Online Learning Center (OLC) Whether you're looking to discover new...

332

WANTED: Undergraduate Research Assistant Betelgeuse's Molecular Inventory  

E-Print Network [OSTI]

WANTED: Undergraduate Research Assistant Betelgeuse's Molecular Inventory GHRS Pre-COSTAR LSA G140L Assistant Opportunity We are seeking an undergraduate research assistant to help make an inventory

Harper, Graham

333

Acting Interns, Assessing When Graduating Medical Students Call for Help, a Simulated Capstone Experience  

E-Print Network [OSTI]

will commonly call for help, often for assistance withMedical Students Call for Help, a Simulated Capstonedeveloped Capstone courses to help prepare medical students

Wald, D; Peet, A

2014-01-01T23:59:59.000Z

334

Visualization of groundwater flow using line integral convolution  

E-Print Network [OSTI]

for the simulation of groundwater flow and transport models. INTRODUCTION Nowadays, 3D numerical simulationsVisualization of groundwater flow using line integral convolution J?RG GOTTHARDT & CAROLA BL?MER of groundwater flow and transport problems become more and more common. At the same time the need for adequate

Andrzejak, Artur

335

Small Business Environmental Assistance Program (Florida)  

Broader source: Energy.gov [DOE]

Through the Small Business Environmental Assistance Program (SBEAP), the Department of Environmental Protection provides technical and regulatory assistance to small businesses. Although SBEAP is...

336

Federal Energy Management Program (FEMP) Technical Assistance...  

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

(FEMP) Technical Assistance Request Portal User Guide Federal Energy Management Program (FEMP) Technical Assistance Request Portal User Guide Document explains how to navigate the...

337

Rural Enterprise Assistance Project's Loan Program (Nebraska)  

Broader source: Energy.gov [DOE]

The Rural Enterprise Assistance Project (REAP) offers four services: financing (micro loans), business training, technical assistance, and networking. REAP's Loan Program focuses on providing...

338

Electrically-Assisted Diesel Particulate Filter Regeneration...  

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

Evaluation pm041lance2011p.pdf More Documents & Publications Electrically-Assisted Diesel Particulate Filter Regeneration Substrate Studies of an Electrically-Assisted Diesel...

339

Monitoring Plan for Weatherization Assistance Program, State...  

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

Monitoring Plan for Weatherization Assistance Program, State Energy Program and Energy Efficiency and Conservation Block Grants Monitoring Plan for Weatherization Assistance...

340

Workshop on hypersonic flow  

SciTech Connect (OSTI)

An overview is given of research activity on the application of computational fluid dynamics (CDF) for hypersonic propulsion systems. After the initial consideration of the highly integrated nature of air-breathing hypersonic engines and airframe, attention is directed toward computations carried out for the components of the engine. A generic inlet configuration is considered in order to demonstrate the highly three dimensional viscous flow behavior occurring within rectangular inlets. Reacting flow computations for simple jet injection as well as for more complex combustion chambers are then discussed in order to show the capability of viscous finite rate chemical reaction computer simulations. Finally, the nozzle flow fields are demonstrated, showing the existence of complex shear layers and shock structure in the exhaust plume. The general issues associated with code validation as well as the specific issue associated with the use of CFD for design are discussed. A prognosis for the success of CFD in the design of future propulsion systems is offered.

Povinelli, L.A.

1990-01-01T23:59:59.000Z

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

Simulation of geothermal subsidence  

SciTech Connect (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

342

Flow chamber  

DOE Patents [OSTI]

A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

Morozov, Victor (Manassas, VA)

2011-01-18T23:59:59.000Z

343

Geological flows  

E-Print Network [OSTI]

In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

Yu. N. Bratkov

2008-11-19T23:59:59.000Z

344

Engineering Organization Chart Assistant Dean  

E-Print Network [OSTI]

Engineering Organization Chart Fall `12 Assistant Dean Outreach & Recruiting Matthew Cavalli and Geological Engineering Joseph Hartman Chair, Petroleum Engineering Steve Benson Chair, Electrical Engineering Forrest Ames (interim) Chair, Mechanical Engineering Matthew Cavalli Chair, Chemical Engineering Mike Mann

Delene, David J.

345

Assistant Professor Cropping Systems Specialist  

E-Print Network [OSTI]

Assistant Professor Cropping Systems Specialist Department of Plant and Soil Sciences POSITION DESCRIPTION The Department of Plant and Soil Sciences, Oklahoma State University is seeking, implementing, and evaluating educational programs to meet the needs of producers for improving existing

Veiga, Pedro Manuel Barbosa

346

Flow Split Venturi, Axially-Rotated Valve  

SciTech Connect (OSTI)

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)

2000-02-22T23:59:59.000Z

347

UZ Flow Models and Submodels  

SciTech Connect (OSTI)

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

348

Environmentally assisted cracking in light water reactors  

SciTech Connect (OSTI)

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995. Topics that have been investigated include fatigue of carbon and low-alloy steel used in reactor piping and pressure vessels, EAC of Alloy 600 and 690, and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS. Fatigue tests were conducted on ferritic steels in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in simulated LWR environments. Effects of fluoride-ion contamination on susceptibility to intergranular cracking of high- and commercial- purity Type 304 SS specimens from control-tensile tests at 288 degrees Centigrade. Microchemical changes in the specimens were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials.

Chopra, O.K.; Chung, H.M.; Gruber, E.E. [and others

1996-07-01T23:59:59.000Z

349

Stress-Assisted Corrosion in Boiler Tubes  

SciTech Connect (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

350

A study of surfactant-assisted waterflooding  

SciTech Connect (OSTI)

In surfactant-assisted waterflooding, a surfactant slug is injected into a reservoir, followed by a brine spacer, followed by second surfactant slug. The charge on the surfactant in the first slug has opposite sign to that in the second slug. When the two slugs mix in the reservoir, a precipitate or coacervate is formed which plugs the permeable region of the reservoir. Subsequently injected water or brine is forced through the low permeability region of the reservoir, increasing sweep efficiency of the waterflood, compared to a waterflood not using surfactants. In this part of the work, two major tasks are performed. First, core floods are performed with oil present to demonstrate the improvement in incremental oil production, as well as permeability modification. Second, a reservoir simulation model will be proposed to further delineate the optimum strategy for implementation of the surfactant-assisted waterflooding, as well as indicate the reservoir types for which it would be most effective. Surfactants utilized were sodium dodecyl sulfate and dodecyl pyridinium chloride. 44 refs., 17 figs., 3 tabs.

Scamehorn, J.F.; Harwell, J.H.

1990-09-01T23:59:59.000Z

351

Technical Assistance Application Energy Partnership Program  

E-Print Network [OSTI]

, public care facility or special district. 2. Project Description Type of assistance needed: Energy audit

352

Feedback control of flow separation using synthetic jets  

E-Print Network [OSTI]

The primary goal of this research is to assess the effect of synthetic jets on flow separation and provide a feedback control strategy for flow separation using synthetic jets. The feedback control synthesis is conducted based upon CFD simulation...

Kim, Kihwan

2006-04-12T23:59:59.000Z

353

Characterizing Flow in Oil Reservoir Rock Using Smooth Particle Hydrodynamics  

E-Print Network [OSTI]

In this paper, a 3D Smooth Particle Hydrodynamics (SPH) simulator for modeling grain scale fluid flow in porous rock is presented. The versatility of the SPH method has driven its use in increasingly complex areas of flow ...

Holmes, David W.

354

Numerical Simulation of Condensation in Transonic Flows  

E-Print Network [OSTI]

set of governing equations . . . . . . . . . . . . . . . . . . 21 2.3.8 Speed of sound equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3.1 Gas-liquid mixtures of the liquid phase . . . . . . . . . . . . . . . . . . . . . 14 2.3.4 Alternative derivation of Hill's Method

Twente, Universiteit

355

NUMERICAL SIMULATION OF INCOMPRESSIBLE FLOWS IN ...  

E-Print Network [OSTI]

u, v and w respectively, and f, g, h, q are functions depending on the solutions at .... and letting A, B, C, D, E, F and U be the corresponding matrices with entries.

356

Spiridon A. Reveliotis Assistant Professor  

E-Print Network [OSTI]

and Simulation, (A. Gheorghe, Ed.), Romanian Acad. Publ. House (1991). 2. Tzafestas, S., Kapsiotis, G

Reveliotis, Spiridon "Spyros"

357

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

358

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

359

Simulation of Radon Transport in Geothermal Reservoirs  

SciTech Connect (OSTI)

Numerical simulation of radon transport is a useful adjunct in the study of radon as an in situ tracer of hydrodynamic and thermodynamic numerical model has been developed to assist in the interpretation of field experiments. The model simulates transient response of radon concentration in wellhead geofluid as a function of prevailing reservoir conditions. The radon simulation model has been used to simulate radon concentration response during production drawdown and two flowrate transient tests in vapor-dominated systems. Comparison of model simulation with experimental data from field tests provides insight in the analysis of reservoir phenomena such as propagation of boiling fronts, and estimates of reservoir properties of porosity and permeability thickness.

Semprini, Lewis; Kruger, Paul

1983-12-15T23:59:59.000Z

360

Simulation- Assisted Audit of an Air Conditioned Office Building  

E-Print Network [OSTI]

Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 performances of the installation. Finally, some significant retrofit opportunities are proposed. BUILDING DESCRIPTION Building design The considered building is an existing... Conference for Enhanced Building Operations, Berlin, Germany, October 20-22, 2008 In nominal heating conditions (outdoor : -10?C/RH 90%; indoor : 20?C/RH50%), with ?t = 30 K, this gives a sensible power demand of: g1843g4662g3046,g3041g3042g3040 =g343623...

Bertagnolio, S.; Lebrun, J.; Hannay, J.; Silva, C. A.

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.


361

Gas Kinetic Scheme for Continuum and Near-Continuum Hypersonic Flows  

E-Print Network [OSTI]

Gas Kinetic Scheme for Continuum and Near-Continuum Hypersonic Flows Wei Liao and Li-Shi Luo Old for the near-continuum flows. The gas-kinetic schemes are validated with simulations of the hypersonic flow thickness, modeling and simulation of complex hypersonic flows become very challenging for computational

Luo, Li-Shi

362

Adiabatic thermal Child-Langmuir flow  

E-Print Network [OSTI]

A simulation model is presented for the verification of the recently developed steady-state one-dimensional adiabatic thermal Child-Langmuir flow theory. In this theory, a self-consistent Poisson equation is developed ...

Mok, Rachel V. (Rachel Verla)

2013-01-01T23:59:59.000Z

363

A survey of air flow models for multizone structures  

SciTech Connect (OSTI)

Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 50 multizone air flow models, all developed since 1966, two of which are still under development. All these programs use similar flow equations for crack flow but differ in the versatility to describe the full range of flow phenomena and the algorithm provided for solving the set of nonlinear equations. This literature review was found that newer models are able to describe and simulate the ventilation systems and interrelation of mechanical and natural ventilation. 27 refs., 2 figs., 1 tab.

Feustel, H.E.; Dieris, J.

1991-03-01T23:59:59.000Z

364

Deashing of coal liquids by sonically assisted filtration  

SciTech Connect (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

365

START Program for Renewable Energy Project Development Assistance...  

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

Program for Renewable Energy Project Development Assistance START Program for Renewable Energy Project Development Assistance The Strategic Technical Assistance Response Team...

366

State and Regional Policy Assistance - Program Activities | Department...  

Office of Environmental Management (EM)

Technical assistance provided to WGAWIEB by the Electricity Market Studies Group of LBNL and The Regulatory Assistance Project (RAP); and More limited technical assistance...

367

Office of the Assistant General Counsel Electricity & Fossil...  

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

Policy Office of the Assistant General Counsel Electricity & Fossil Energy Office of the Assistant General Counsel Electricity & Fossil Energy The Office of the Assistant...

368

LANL, Sandia celebrate success at New Mexico Small Business Assistance...  

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

success at NM Small Business Assistance fest LANL, Sandia celebrate success at New Mexico Small Business Assistance fest The New Mexico Small Business Assistance (NMSBA)...

369

Laura M. Grabowski Assistant Professor  

E-Print Network [OSTI]

" Advisor: Dr. Richard Fowler MASTER OF ARTS May 1983 Communications/Theatre Bowling Green State University Committee Chair BACHELOR OF ARTS June 1980 Major: French; Minor: Dance Bowling Green State University Department of Theatre Bowling Green State University, Bowling Green, Ohio Graduate Teaching Assistant August

Grabowski, Laura M. - Department of Computer Science, University of Texas

370

Assistant Director, Prospect Management Description  

E-Print Network [OSTI]

and to the Prospect Management Data Wranglers to assist their efforts in improving the quality of Prospect Management Management Enter and monitor prospect assignments and new prospect records requests. Monitor data quality of all functions and systems related to prospect management, including software applications, industry

Portman, Douglas

371

Assistant Secretary Hoffman Discusses Grid Modernization with...  

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

Assistant Secretary Hoffman Discusses Grid Modernization with the New York Times and E&E TV Assistant Secretary Hoffman Discusses Grid Modernization with the New York Times and E&E...

372

Energy Technical Assistance: Industrial Processes Program  

E-Print Network [OSTI]

The Energy Technical Assistance Division of Texas Engineering Extension Service (TEEX) has implemented an energy conservation program to assist small industry in using energy more efficiently. This full time service, an outgrowth of the Texas A...

McClure, J. D.

1980-01-01T23:59:59.000Z

373

Grounded Situation Models for Situated Conversational Assistants  

E-Print Network [OSTI]

A Situated Conversational Assistant (SCA) is a system with sensing, acting and speech synthesis/recognition abilities, which engages in physically situated natural language conversation with human partners and assists them ...

Mavridis, Nikolaos

2007-01-01T23:59:59.000Z

374

Numerical simulation of three-dimensional combined convective radiative heat transfer in rectangular channels  

E-Print Network [OSTI]

This dissertation presents a numerical simulation of three-dimensional flow and heat transfer in a channel with a backward-facing step. Flow was considered to be steady, incompressible, and laminar. The flow medium was treated to be radiatively...

Ko, Min Seok

2009-05-15T23:59:59.000Z

375

PERFORMANCE OF FULLY-COUPLED DOMAIN DECOMPOSITION PRECONDITIONERS for FINITE ELEMENT TRANSPORT / REACTION SIMULATIONS1  

E-Print Network [OSTI]

element simulation of strongly coupled fluid flow, heat transfer, and mass transfer with non methods, stabilized finite element methods. 1. INTRODUCTION Modern computational fluid dynamics flows with unstructured mesh finite element methods. These flow problems are characterized by both

Tuminaro, Ray S.

376

Obtaining Disaster Assistance for Public Infrastructure  

E-Print Network [OSTI]

?s Divi- sion of Emergency Management. FEMA will communicate with local governments about the process of ap- plying under its Public Assistance Program. The information also is found on the FEMA Web site http://www.fema.gov/rrr/pa/. Eligible applicants... Public Assistance pro- gram, the FEMA Hazard Mitigation Grant Program (HMGP), and other aid programs. USDA Rural Development assistance for water infrastructure may be available through Emer- gency Community Water Assistance Grants. http://www.usda.gov...

Taylor, Greg

2005-10-10T23:59:59.000Z

377

Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons...  

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

Ferromagnetic Amorphous Ribbons: A Multimodal Characterization and Thermal Model Study. Laser Assisted Crystallization of Ferromagnetic Amorphous Ribbons: A Multimodal...

378

Radiological Assistance Program | National Nuclear Security Administra...  

National Nuclear Security Administration (NNSA)

Federal Radiological Monitoring and Assessment Center Emergency Response Accident Response Group Radiation Emergency Assistance Center Training Site National Atmospheric Release...

379

(Preview Draft) Chapter 4. Accumulating the Flows  

E-Print Network [OSTI]

't take long because you only needed to update the stock very dec as a combination of stocks and flows and then simulated on the computer. The simulation results are generated adopted for this example. CO2 in the atmosphere is a stock measured in Gigatons of Carbon, abbreviated GTC

Ford, Andrew

380

Graduate Assistant Stipend Enhancement Project Proposal Type  

E-Print Network [OSTI]

1 Graduate Assistant Stipend Enhancement Project Proposal Type The Graduate Assistant Stipend Strategic Plan. Goals The Graduate Assistant Stipend Enhancement project consists of two programs: the Great. Fundamentally, the project seeks to increase the number of graduate students who receive assistantships

Karonis, Nicholas T.

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

START Renewable Energy Project Development Assistance  

Broader source: Energy.gov [DOE]

The DOE Office of Indian Energy is now accepting applications for the third round of the Strategic Technical Assistance Response Team (START) Renewable Energy Project Development Assistance Program to provide Tribes with technical assistance with furthering the development of community- and commercial-scale renewable energy projects. Applications are due May 1, 2015, and up to five projects will be selected in June 2015.

382

Statistical Assistant Research Data Centre, Queens University  

E-Print Network [OSTI]

JOB OFFER Statistical Assistant Research Data Centre, Queens University Position: Statistical Assistant at the RDC, Queens University Classification: Statistics Canada term part-time CR-04 Salary: $ 44, etc.) - Provide basic assistance on the use of the computer network and statistical software

Graham, Nick

383

WARREN RESIDENTIAL LIFE RESIDENT ASSISTANT POSITION DESCRIPTION  

E-Print Network [OSTI]

WARREN RESIDENTIAL LIFE RESIDENT ASSISTANT POSITION DESCRIPTION The position of Resident Assistant for students living within the Warren College residential community. Resident Assistant's (RA's) are principle members of the Warren Residential Life staff. In accordance with the University of California's Personnel

Russell, Lynn

384

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

385

The Effect of High Rotational Speed on the Performance of Straight-through Labyrinth Seals for Compressible and Incompressible Flow  

E-Print Network [OSTI]

The leakage flow through straight through labyrinth seals with tooth on stator was investigated by performing CFD simulations .ANSYS Fluent is used to simulate the fluid flow through straight through Labyrinth seals. The effect of seal geometry...

Obidigbo, Ekene R.

2012-07-16T23:59:59.000Z

386

Building Technologies Office: EnergyPlus Energy Simulation Software  

Energy Savers [EERE]

modular systems and plant integrated with heat balance-based zone simulation, multizone air flow, thermal comfort, water use, natural ventilation, and photovoltaic systems. Read...

387

Modeling-Computer Simulations At Long Valley Caldera Geothermal...  

Open Energy Info (EERE)

Modeling-Computer Simulations Activity Date - 2003 Usefulness not indicated DOE-funding Unknown Notes Several fluid-flow models presented regarding the Long Valley Caldera....

388

Electrically-Assisted Turbocharger Development for Performance and Emissions  

SciTech Connect (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

389

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

390

Computer Assisted Parallel Program Generation  

E-Print Network [OSTI]

Parallel computation is widely employed in scientific researches, engineering activities and product development. Parallel program writing itself is not always a simple task depending on problems solved. Large-scale scientific computing, huge data analyses and precise visualizations, for example, would require parallel computations, and the parallel computing needs the parallelization techniques. In this Chapter a parallel program generation support is discussed, and a computer-assisted parallel program generation system P-NCAS is introduced. Computer assisted problem solving is one of key methods to promote innovations in science and engineering, and contributes to enrich our society and our life toward a programming-free environment in computing science. Problem solving environments (PSE) research activities had started to enhance the programming power in 1970's. The P-NCAS is one of the PSEs; The PSE concept provides an integrated human-friendly computational software and hardware system to solve a target ...

Kawata, Shigeo

2015-01-01T23:59:59.000Z

391

assisted reproductive technology: Topics by E-print Network  

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

consumer information. Referral Date: Consumer's Name: Date of Birth Assistive Technology Assessment Computer Skills Assessment Assistive TechnologyComputer...

392

assisted reproduction technology: Topics by E-print Network  

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

consumer information. Referral Date: Consumer's Name: Date of Birth Assistive Technology Assessment Computer Skills Assessment Assistive TechnologyComputer...

393

assisted reproduction technologies: Topics by E-print Network  

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

consumer information. Referral Date: Consumer's Name: Date of Birth Assistive Technology Assessment Computer Skills Assessment Assistive TechnologyComputer...

394

Simulation of LMFBR  

SciTech Connect (OSTI)

The title of this session is taken to imply the system-wide thermohydraulic simulation of liquid metal fast breeder reactors (LMFBR). One is interested in predicting the temperatures, pressures, and the coolant flow rates throughout the entire plant including the reactor core, the primary and secondary sodium heat transport circuits, the steam generating system as well as other auxiliary circuits. Such a simulation is needed for (1) scoping studies (i.e., in the pre-design phase of a plant), (2) detailed design development, (3) the safety analysis (post-design development phase), and (4) the operator training and plant operation. This session emphasizes the simulation of LMFBRs for only two key categories of transients: operational disturbances or events and the post-shutdown heat removal.

Agrawal, A.K.

1982-01-01T23:59:59.000Z

395

Federal Renewable Energy Screening Assistant  

SciTech Connect (OSTI)

The Federal Renewable Energy Screening Assistant is a software tool to be used by energy auditors to prioritize future studies of potentially cost-effective renewable energy applications at federal facilities. This paper describes the structure and function of the tool, gives an inventory of renewable energy technologies represented in the tool, and briefly describes the algorithms used to rank opportunities by the savings-to-investment ratio.

Shelpuk, B [Natural Energy Resources Unlimited, Evergreen, CO (United States); Walker, A [National Renewable Energy Lab., Golden, CO (United States)

1994-10-01T23:59:59.000Z

396

ARM Assists Lilac Phenology Network  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)Productssondeadjustsondeadjust Documentation DataProductswsicloudwsicloudsummarygifAOS3 ARM Assists Lilac

397

Technical Assistance | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustionImprovement Award Secretary's ImprovementSNL for theServices » WasteTechnical Assistance

398

Magnetic Amplifier for Power Flow Control  

SciTech Connect (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. ORNLs 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 ORNLs device could serve as a low-cost alternative that is equally adept at regulating power flow.

None

2012-02-24T23:59:59.000Z

399

(Preview Draft) Chapter 5. Water Flows in the Mono Basin  

E-Print Network [OSTI]

of people began a campaign to save a dying lake, taking on not only the City of Los Angeles, but the entire a modeling point of view, Mono Lake is well suited to demonstrate the power of stock and flow modeling. We will be simulating the flows and accumulation of water, so the stock and flow concepts will be easy to understand

Ford, Andrew

400

A general-purpose, geochemical reservoir simulator  

SciTech Connect (OSTI)

A geochemical simulator for the analysis of coupled reaction and transport processes is presented. The simulator is based on the numerical solution of the equations of coupled multi-phase fluid flow, species transport, energy balance and rock/fluid reactions. It also accounts for the effects of grain growth/dissolution and the alteration of porosity and permeability due to mineral reactions. The simulator can be used to analyze core floods, single-well scenarios and multiple production/injection well systems on the reservoir scale. Additionally, the simulator provides two flow options: the Darcy law for fluid flow in porous media and the Brinkman law that subsumes both free and porous medium flows. The simulator was tested using core acidizing data and results were in good agreement with laboratory observations. The simulator was applied to analyze matrix acidizing treatments for a horizontal well. The evolution of the skin factor was predicted and the optimal volume of acid required to remove the near-wellbore damage was determined. Reactive fluid infiltration was shown to lead to reaction-front fingering under certain conditions. Viscosity contrast in multiphase flow could also result in viscous fingering. Examples in this study also address these nonlinear fingering phenomena. A waterflood on the reservoir scale was analyzed and simulation results show that scale formation during waterfloods can occur far beyond injection wells. Two cases of waste disposal by deep well injection were evaluated and our simulation results were consistent with field measured data.

Liu, X.; Ortoleva, P.

1996-12-31T23:59:59.000Z

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
to obtain the most current and comprehensive results.


401

Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes  

E-Print Network [OSTI]

Laminar, two-dimensional, constant-property numerical simulations of flat tube heat exchanger devices operating in flow regimes in which self-sustained oscillations occur were performed. The unsteady flow regimes were transition flow regimes...

Fullerton, Tracy

2012-02-14T23:59:59.000Z

402

SFTEL: Flow Cell | EMSL  

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

Flow Cell EMSL's Subsurface Flow and Transport Experimental Laboratory offers several meter-scale flow cells and columns for research in saturated and unsaturated porous media....

403

Parallel-Flow-Shear Driven Low-Frequency Plasma Instability  

SciTech Connect (OSTI)

Full three dimensional Particle-in-Cell (PIC) simulations are performed in order to investigate effects of field-aligned (parallel) ion flow shears on low-frequency plasma instabilities. It is shown that the parallel ion flow velocity shear can induce the ion-acoustic instability, even when the ion flow velocity is so small that the instability can not take place. Simulation results are consistent with the analysis based on the local theory.

Ishiguro, Seiji [Theory and Computer Simulation Center, National Institute for Fusion Science, Toki-shi, Gifu 509-5292 (Japan); Matsumoto, Noriaki; Kaneko, Toshiro; Hatakeyama, Rikizo [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan)

2004-12-01T23:59:59.000Z

404

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

405

Assistance  

Broader source: Energy.gov [DOE]

The Department of Energy (DOE) assurance systems are designed to meet the needs and unique risks of each DOE site or activity, include methods to perform rigorous self-assessments, conduct feedback...

406

Dexterity optimization by port placement in robot-assisted minimally invasive surgery  

E-Print Network [OSTI]

Dexterity optimization by port placement in robot-assisted minimally invasive surgery Shaun Selha1 port triplets ranked according to tool dexterity and endoscopic view quality at each surgical site involved in a procedure. A computer simulation allows the surgeon to select from among the proposed port

Dupont, Pierre

407

Cost-Effective Multi-Mode Offloading with peer-assisted communications  

E-Print Network [OSTI]

cost in terms of financial settlement, energy consump- tion, and user satisfaction. Our simulationsCost-Effective Multi-Mode Offloading with peer-assisted communications Ioannis Komnios a, , Fani caused by the ongoing explosive growth in mobile data traffic. In this paper, we propose Cost

Gorinsky, Sergey

408

Jet quenching and elliptic flow  

E-Print Network [OSTI]

In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. Assuming that the deposited energy quickly thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP fluid. Explicit simulation of Au+Au collision with and without a quenching jet indicate that elliptic flow is greatly reduced in a jet event. The result can be used to identify the jet events in heavy ion collisions.

A. K. Chaudhuri

2007-08-29T23:59:59.000Z

409

ICAS2002 CONGRESS SIMULATION TECHNIQUES IN HYPERSONIC  

E-Print Network [OSTI]

ICAS2002 CONGRESS SIMULATION TECHNIQUES IN HYPERSONIC AEROTHERMODYNAMICS Vladimir V. Riabov Rivier College, Nashua, New Hampshire 03060, USA Keywords: hypersonic non-equilibrium rarefied-gas flows, aero- & thermodynamic coefficients Abstract Hypersonic viscous flows near simple-shape bodies (wedge, cone, disk, plate

Riabov, Vladimir V.

410

Assistive Technology | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles » Alternative FuelNewsWashington AutoYourAppliance andAssistive

411

Financial Assistance | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles »Exchange Visitors ProgramEnergy Fall intoAssistance Financial

412

Gas-Kinetic Scheme for Continuum and Near-Continuum Hypersonic Flows  

E-Print Network [OSTI]

Gas-Kinetic Scheme for Continuum and Near-Continuum Hypersonic Flows Wei Liao and Li-Shi Luo Old. The gas-kinetic schemes are validated with simulations of the hypersonic flow past a hollow flare at Mach and simulation of complex hypersonic flows become very challenging for computa- tional fluid dynamics (CFD) [1

Xu, Kun

413

Subgrid-scale model for the temperature fluctuations in reacting hypersonic turbulent flows  

E-Print Network [OSTI]

Subgrid-scale model for the temperature fluctuations in reacting hypersonic turbulent flows M. Pino fluctuations for use in large-eddy simulations of turbulent, reacting hypersonic flows. The proposed model uses, a greater understand- ing of turbulent hypersonic flows is needed. Direct numerical simulations DNS

Martín, Pino

414

Quantum Simulation  

E-Print Network [OSTI]

Simulating quantum mechanics is known to be a difficult computational problem, especially when dealing with large systems. However, this difficulty may be overcome by using some controllable quantum system to study another less controllable or accessible quantum system, i.e., quantum simulation. Quantum simulation promises to have applications in the study of many problems in, e.g., condensed-matter physics, high-energy physics, atomic physics, quantum chemistry and cosmology. Quantum simulation could be implemented using quantum computers, but also with simpler, analog devices that would require less control, and therefore, would be easier to construct. A number of quantum systems such as neutral atoms, ions, polar molecules, electrons in semiconductors, superconducting circuits, nuclear spins and photons have been proposed as quantum simulators. This review outlines the main theoretical and experimental aspects of quantum simulation and emphasizes some of the challenges and promises of this fast-growing field.

I. M. Georgescu; S. Ashhab; Franco Nori

2014-03-13T23:59:59.000Z

415

Intelligent interface for design and simulation  

SciTech Connect (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

416

Flow enhancement in nanotubes of different materials and lengths  

SciTech Connect (OSTI)

The high water flow rates observed in carbon nanotubes (CNTs) have previously been attributed to the unfavorable energetic interaction between the liquid and the graphitic walls of the CNTs. This paper reports molecular dynamics simulations of water flow in carbon, boron nitride, and silicon carbide nanotubes that show the effect of the solid-liquid interactions on the fluid flow. Alongside an analytical model, these results show that the flow enhancement depends on the tube's geometric characteristics and the solid-liquid interactions.

Ritos, Konstantinos, E-mail: konstantinos.ritos@strath.ac.uk [James Weir Fluids Lab, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)] [James Weir Fluids Lab, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Mattia, Davide [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom)] [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom); Calabr, Francesco [DIEI, Universit di Cassino e del Lazio Meridionale, 03043 Cassino (Italy)] [DIEI, Universit di Cassino e del Lazio Meridionale, 03043 Cassino (Italy); Reese, Jason M. [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)] [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

2014-01-07T23:59:59.000Z

417

Assistance Focus: Asia/Pacific Region (Brochure)  

SciTech Connect (OSTI)

The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to governments in the Asia/Pacific region, including the benefits of that assistance.

Not Available

2015-01-01T23:59:59.000Z

418

Assistance Focus: Latin America/Caribbean (Brochure)  

SciTech Connect (OSTI)

The Clean Energy Solutions Center Ask an Expert service connects governments seeking policy information and advice with one of more than 30 global policy experts who can provide reliable and unbiased quick-response advice and information. The service is available at no cost to government agency representatives from any country and the technical institutes assisting them. This publication presents summaries of assistance provided to African governments, including the benefits of that assistance.

Not Available

2015-01-01T23:59:59.000Z

419

EV Project: Solar-Assisted Charging Demo  

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

Melissa Lapsa 2014 DOE Vehicle Technologies Office Review Presentation EV Project - Solar- Assisted Charging Demo VSS138 2014 U.S. DOE Hydrogen Program and Vehicle Technologies...

420

Energy Innovation Assistance Program (EIAP) (Quebec, Canada)  

Broader source: Energy.gov [DOE]

The Energy innovation assistance program (PAIE) aims to encourage the development of new technologies or innovative processes focusing on energy efficiency or emerging energy sources by financially...

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

EPA Indian Environmental General Assistance Program  

Broader source: Energy.gov [DOE]

The U.S. Environmental Protection Agency (EPA) is seeking grant proposals for the Indian Environmental General Assistance Program (GAP) for FY 2016 work plan program development activities.

422

USDA- Repowering Assistance Biorefinery Program (Federal)  

Broader source: Energy.gov [DOE]

The Repowering Assistance Program provides payments to eligible biorefineries to replace fossil fuels used to produce heat or power to operate the biorefineries with renewable biomass....

423

Radiological Assistance Program | National Nuclear Security Administra...  

National Nuclear Security Administration (NNSA)

(trained personnel and equipment) to evaluate, assess, advise, isotopically identify, search for, and assist in the mitigation of actual or perceived nuclear or radiological...

424

American Recovery and Reinvestment Act, Financial Assistance...  

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

- ARRAAttachment3.rtf FOIA Frequently Requested Documents: DE-EE0002884 Recovery Act - Integrated Algal Biorefinery (IABR) Financial Assistance Funding Opportunity Announcement...

425

Electricity Policy Technical Assistance Program | Department...  

Energy Savers [EERE]

Program Electricity Policy Technical Assistance Program Overview Since 2003, the U.S. Department of Energy's Office of Electricity Delivery and Energy Reliability (OE) has been...

426

Weatherization Assistance Program (WAP) Closeout Frequently Asked...  

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

Program (WAP) Closeout Frequently Asked Questions Weatherization Assistance Program (WAP) Closeout Frequently Asked Questions This document provides a list of frequently asked...

427

Research Assistant (Econometrics Specialist) -Centro de Estudios Puertorriqueos Job Title: Research Assistant (Econometrics Specialist)  

E-Print Network [OSTI]

Research Assistant (Econometrics Specialist) - Centro de Estudios Puertorriqueos Job Title: Research Assistant (Econometrics Specialist) Centro de Estudios Puertorriqueos Job ID: 10155 Location related field is preferred. Training in econometrics and experience in applying econometrics are required

Qiu, Weigang

428

A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California  

SciTech Connect (OSTI)

This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

2006-05-16T23:59:59.000Z

429

Precision electron flow measurements in a disk transmission line.  

SciTech Connect (OSTI)

An analytic model for electron flow in a system driving a fixed inductive load is described and evaluated with particle in cell simulations. The simple model allows determining the impedance profile for a magnetically insulated transmission line given the minimum gap desired, and the lumped inductance inside the transition to the minimum gap. The model allows specifying the relative electron flow along the power flow direction, including cases where the fractional electron flow decreases in the power flow direction. The electrons are able to return to the cathode because they gain energy from the temporally rising magnetic field. The simulations were done with small cell size to reduce numerical heating. An experiment to compare electron flow to the simulations was done. The measured electron flow is {approx}33% of the value from the simulations. The discrepancy is assumed to be due to a reversed electric field at the cathode because of the inductive load and falling electron drift velocity in the power flow direction. The simulations constrain the cathode electric field to zero, which gives the highest possible electron flow.

Clark, Waylon T.; Pelock, Michael D.; Martin, Jeremy Paul; Jackson, Daniel Peter Jr.; Savage, Mark Edward; Stoltzfus, Brian Scott; Mendel, Clifford Will, Jr.; Pointon, Timothy David

2008-01-01T23:59:59.000Z

430

Health Resources Employee Assistance Program  

E-Print Network [OSTI]

Generation of Cognitive Behavior (Playing Chess, etc.) · Involvement of Entire Perceptual-Cognitive System Busters Stressed at work? Stressed at home? Did you know that stress is now the #1 reason behind sickness and flow of your breath. This calms the body. · Imagine an energy bubble, like a balloon, around you

Fraden, Seth

431

K. A. Thole^ Assistant Professor.  

E-Print Network [OSTI]

- tained by increasing turbine inlet temperatures. One such blade cooling technique is film-cooling whereby compressor bleed air is exhausted through the turbine blade surface through cooling holes. These holes at the Entrance to a Film-Cooling Hole Understanding the complex flow ofjets issuing into a crossflow from

Thole, Karen A.

432

Flow reversal power limit for the HFBR  

SciTech Connect (OSTI)

The High Flux Beam Reactor (HFBR) undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Uncertainties about the afterheat removal capability during the flow reversal has limited the reactor operating power to 30 MW. An experimental and analytical program to address these uncertainties is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW.

Cheng, Lap Y.; Tichler, P.R.

1995-10-01T23:59:59.000Z

433

E-Print Network 3.0 - assistant editor stamatios Sample Search...  

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

Information Summary: Assistant Jose Cano Facilities Assistant Jackie Trang Electronic Media Editor Many Smith Graduate Admissions... Personnel Assistant Facilities Gershwin...

434

Site-Scale Saturated Zone Flow Model  

SciTech Connect (OSTI)

The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca Mountain using FEHM V 2.20 are being carried out in the model report, ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The velocity fields are calculated by the flow model, described herein, independent of the transport processes, and are then used as inputs to the transport model. Justification for this abstraction is presented in the model report, ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021 (BSC 2003 [164870]).

G. Zyvoloski

2003-12-17T23:59:59.000Z

435

Separation of particles from gaseous fluid flows  

SciTech Connect (OSTI)

In a gas washer and similar separator devices which utilize stationary wall means to deflect a gas flow and to subject the same to centrifugal force for continuously separating out foreign particulate matter which is collected on or adjacent the stationary wall means, the invention provides spirally curved laminae constituting the stationary wall means and co-operating to define passage means, at least a part of which has a cross-section which first narrows and then widens in the direction of fluid flow and which is also curved spirally first in one and then in the opposite direction. Nozzle means may be arranged to feed moisture into the fluid flow to assist wet separation, and by electrically insulating conductive laminae from one another, the invention may also be used as an electrostatic precipitator.

Paul, E.; Reither, K.

1980-12-16T23:59:59.000Z

436

Chemically assisted mechanical refrigeration process  

DOE Patents [OSTI]

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Vobach, A.R.

1987-11-24T23:59:59.000Z

437

Chemically assisted mechanical refrigeration process  

DOE Patents [OSTI]

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Vobach, A.R.

1987-06-23T23:59:59.000Z

438

Dr. Krisellen Maloney Assistant Dean for  

E-Print Network [OSTI]

Instructional Designer Heather Williams Instructional Designer Rocio Chavez Multimedia Specialist Joel Juarez Assistant IV (3 pm ­ 12 pm) Alexandra Williams Library Services Assistant III Student Supervisor Paul Scholarly Resources Librarian Jeff McAdams Charles Wu Reference Librarian Jacob Sherman Seth Gamini Haluwana

Dodla, Ramana

439

Instructions for use JICA's Assistance in Health  

E-Print Network [OSTI]

and clinical care eg, strengthen health systems including the development of human resources, facilitiesInstructions for use #12;1 JICA's Assistance in Health Ryuji MATSUNAGA International Cooperation's Assistance in Health Example of JICA Programme/Projects 2 #12;An Overview of Japan's ODA 3 #12;Japan's ODA

Tsunogai, Urumu

440

Assistant or Associate Professor in Sedimentology  

E-Print Network [OSTI]

Assistant or Associate Professor in Sedimentology The Department of Earth Sciences (DES), Mineral for a tenure-track Assistant or Associate Professor position in Sedimentology to begin in July 2015. We seek an innovative individual with excellent teaching and research skills in sedimentology. Expertise in Precambrian

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

Consulting Assistance on Economic Discussion Papers  

E-Print Network [OSTI]

Consulting Assistance on Economic Reform II Discussion Papers The objectives of the Consulting Assistance on Economic Reform (CAER II) project are to contribute to broad-based and sustainable economic, Bureau for Global Programs, Field Support and Research, Center for Economic Growth and Agricultural

442

Renewable Energy Project Development Assistance (Fact Sheet)  

SciTech Connect (OSTI)

This fact sheet provides information on the Tribes selected to receive assistance from the U.S. Department of Energy Office of Indian Energy 2013 Strategic Technical Assistance Response Team (START) Program, which provides technical expertise to support the development of next-generation energy projects on tribal lands.

Not Available

2013-07-01T23:59:59.000Z

443

An Integrated Modeling Analysis of Unsaturated Flow Patterns in Fractured Rock  

E-Print Network [OSTI]

study, heat flow simulations use a 3-D thermal model grid (model grid, which is used for gas flow and ambient heat-flowgrid showing a smaller model domain, used for modeling gas and heat

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson, Gudmundur S.

2008-01-01T23:59:59.000Z

444

Analyzing flow patterns in unsaturated fractured rock of Yucca Mountain using an integrated modeling approach  

E-Print Network [OSTI]

heat flow simulations use the 3-D thermal model grid (Figuremodel grid, which is used for gas flow and ambient heat flowgrid showing a smaller model domain, used for modeling gas and heat

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson, Gudmundur S.

2008-01-01T23:59:59.000Z

445

E-Print Network 3.0 - air-cooled low-flow torch Sample Search...  

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

22 Electrical discharges in theElectrical discharges in the Reverse Vortex FlowReverse Vortex Flow Summary: Numerical Simulation for 3.5kW Microwave Plasma Stabilization with...

446

Slide 2 What is the Office of Employee Assistance Services? The Office of Employee Assistance Services incorporates several employee services  

E-Print Network [OSTI]

Slide 2 What is the Office of Employee Assistance Services? The Office of Employee Assistance Development Slide 3 Why does FSU have an Office of Employee Assistance Services? The Office of Employee need it. Slide 4 How can the Office of Employee Assistance Services help me? The "Employee Assistance

Weston, Ken

447

Flow focusing in unsaturated fracture networks: A numerical investigation  

SciTech Connect (OSTI)

A numerical modeling study is presented to investigate flow-focusing phenomena in a large-scale fracture network, constructed using field data collected from the unsaturated zone of Yucca Mountain, Nevada, the proposed repository site for high-level nuclear waste. The two-dimensional fracture network for an area of 100 m x 150 m contains more than 20,000 fractures. Steady-state unsaturated flow in the fracture network is investigated for different boundary conditions and rock properties. Simulation results indicate that flow paths are generally vertical, and that horizontal fractures mainly provide pathways between neighboring vertical paths. In addition to fracture properties, flow-focusing phenomena are also affected by rock-matrix permeability, with lower matrix permeability leading to a high degree of flow focusing. The simulation results further indicate that the average spacing between flow paths in a layered system tends to increase and flow tends to becomes more focused, with depth.

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

2003-04-17T23:59:59.000Z

448

Low volume flow meter  

DOE Patents [OSTI]

The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

Meixler, Lewis D. (East Windsor, NJ)

1993-01-01T23:59:59.000Z

449

Well correction factors for three-dimensional reservoir simulation  

E-Print Network [OSTI]

of Advisory Committee: Dr. W. D. Von Gonten A three-dimensional reservoir simulation model does not calculate the correct bottomhole flowing pressure, p f, for a partially penetrating well. The simulator well cell pressure must be corrected ro obtain... an accurate value for p f. Simulation model results have wf' been used in this part to develop a new inflow equation relating cell pressure to actual bottomhole flowing pressure for a partially penetrating well. Based on the new inflow equation, an equation...

Fjerstad, Paul Albert

1985-01-01T23:59:59.000Z

450

Pacific Adaptation Strategy Assistance Program Dynamical Seasonal Forecasting  

E-Print Network [OSTI]

Pacific Adaptation Strategy Assistance Program Dynamical Seasonal Forecasting Seasonal Prediction · POAMA · Issues for future Outline #12;Pacific Adaptation Strategy Assistance Program Major source Adaptation Strategy Assistance Program El Nino Mean State · Easterlies westward surface current upwelling

Lim, Eun-pa

451

FLIGHT SIMULATION FOR THE DEVELOPMENT OF AN EXPERIMENTAL UAV Eric N. Johnson* and Sumit Mishra  

E-Print Network [OSTI]

FLIGHT SIMULATION FOR THE DEVELOPMENT OF AN EXPERIMENTAL UAV Eric N. Johnson* and Sumit Mishra. _____________ * Lockheed Martin Assistant Professor of Avionics Integration, Member AIAA. E-mail: Eric.Johnson

Johnson, Eric N.

452

Oxygen-assisted multipass cutting of carbon fiber reinforced plastics with ultra-short laser pulses  

SciTech Connect (OSTI)

Deep multipass cutting of bidirectional and unidirectional carbon fiber reinforced plastics (CFRP) with picosecond laser pulses was investigated in different static atmospheres as well as with the assistance of an oxygen or nitrogen gas flow. The ablation rate was determined as a function of the kerf depth and the resulting heat affected zone was measured. An assisting oxygen gas flow is found to significantly increase the cutting productivity, but only in deep kerfs where the diminished evaporative ablation due to the reduced laser fluence reaching the bottom of the kerf does not dominate the contribution of reactive etching anymore. Oxygen-supported cutting was shown to also solve the problem that occurs when cutting the CFRP parallel to the fiber orientation where a strong deformation and widening of the kerf, which temporarily slows down the process speed, is revealed to be typical for processing in standard air atmospheres.

Kononenko, T. V.; Komlenok, M. S.; Konov, V. I. [Natural Sciences Center, General Physics Institute, Vavilov str. 38, 119991 Moscow (Russian Federation); National Research Nuclear University, MEPhI, Kashirskoye shosse 31, 115409 Moscow (Russian Federation); Freitag, C. [Universitt Stuttgart, Institut fr Strahlwerkzeuge (IFSW), Pfaffenwaldring 43, 70569 Stuttgart (Germany); GSaME Graduate School of Excellence Advanced Manufacturing Engineering, Nobelstrasse 12, 70569 Stuttgart (Germany); Onuseit, V.; Weber, R.; Graf, T. [Universitt Stuttgart, Institut fr Strahlwerkzeuge (IFSW), Pfaffenwaldring 43, 70569 Stuttgart (Germany)

2014-03-14T23:59:59.000Z

453

Propeller Flow Meter  

E-Print Network [OSTI]

Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....

Enciso, Juan; Santistevan, Dean; Hla, Aung K.

2007-10-01T23:59:59.000Z

454

Dispersed flow film boiling  

E-Print Network [OSTI]

Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

Yoder, Graydon L.

1980-01-01T23:59:59.000Z

455

Bacteria in shear flow  

E-Print Network [OSTI]

Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

Marcos, Ph.D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

456

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator aka FALCON: Fracturing and Liquid CONservation Robert K....

457

A correction function method to solve incompressible fluid flows to high accuracy with immersed geometries  

E-Print Network [OSTI]

Numerical simulations of incompressible viscous flows in realistic configurations are increasingly important in many scientific and engineering fields. In Aeronautics, for instance, relatively cheap numerical computations ...

Marques, Alexandre Noll

2012-01-01T23:59:59.000Z

458

START Program for Renewable Energy Project Development Assistance...  

Office of Environmental Management (EM)

START Program for Renewable Energy Project Development Assistance - Round Three Application START Program for Renewable Energy Project Development Assistance - Round Three...

459

EERE Assistant Secretary and BETO Director Confirmed Speakers...  

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

EERE Assistant Secretary and BETO Director Confirmed Speakers for Algae Biomass Summit EERE Assistant Secretary and BETO Director Confirmed Speakers for Algae Biomass Summit...

460

Technical Assistance Resources for State, Local, and Tribal Energy...  

Energy Savers [EERE]

& Local Solution Center Technical Assistance Resources for State, Local, and Tribal Energy Programs Technical Assistance Resources for State, Local, and Tribal Energy Programs...

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.


461

Load Expansion of Stoichiometric HCCI Using Spark Assist and...  

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

of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Load Expansion of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation Presentation given at...

462

Effective Community-Wide Policy Technical Assistance: The NREL...  

Open Energy Info (EERE)

Wide Policy Technical Assistance: The NRELDOE Approach Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Effective Community-Wide Policy Technical Assistance: The NREL...

463

Assistant Secretary Cathy Zoi and Senior Advisor Matt Rogers...  

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

Assistant Secretary Cathy Zoi and Senior Advisor Matt Rogers to Participate in Platts Energy Reporter Roundtable Assistant Secretary Cathy Zoi and Senior Advisor Matt Rogers to...

464

Assistance Program, State Energy Program, Energy Efficiency and...  

Energy Savers [EERE]

Assistance Program, State Energy Program, Energy Efficiency and Conservation Block Grants Assistance Program, State Energy Program, Energy Efficiency and Conservation Block Grants...

465

Office of the Assistant General Counsel for Legislation, Regulation...  

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

Office of the Assistant General Counsel for Legislation, Regulation and Energy Efficiency Office of the Assistant General Counsel for Legislation, Regulation and Energy...

466

Contacts for the Assistant General Counsel for Legislation, Regulation...  

Energy Savers [EERE]

Legislation, Regulation, and Energy Efficiency Contacts for the Assistant General Counsel for Legislation, Regulation, and Energy Efficiency Office of the Assistant General Counsel...

467

Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel...  

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

Assisted Diesel Combustion in a Common Rail Turbodiesel Engine P-3 Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel Engine P-3 Gregory Lilik, Jos Martn...

468

Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel...  

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

Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel Engine Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel Engine This study measured the effects of...

469

Office of the Assistant General Counsel for Technology Transfer...  

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

Technology Transfer & Intellectual Property Office of the Assistant General Counsel for Technology Transfer & Intellectual Property The Office of the Assistant General Counsel for...

470

Energy Savings Performance Contract Project Assistance for Agencies...  

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

Savings Performance Contract Project Assistance for Agencies Energy Savings Performance Contract Project Assistance for Agencies Fact sheet details an overview of Federal Energy...

471

Catalyst-Assisted Production of Olefins from Natural Gas Liquids...  

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

Catalyst-Assisted Production of Olefins from Natural Gas Liquids: Prototype Development and Full-Scale Testing, April 2013 Catalyst-Assisted Production of Olefins from Natural Gas...

472

Electric Markets Technical Assistance Program: FY1999 Grant Descriptio...  

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

Markets Technical Assistance Program: FY1999 Grant Descriptions and Contact Information Electric Markets Technical Assistance Program: FY1999 Grant Descriptions and Contact...

473

START Program for Renewable Energy Project Development Assistance...  

Energy Savers [EERE]

Program for Renewable Energy Project Development Assistance Non-Disclosure Agreement START Program for Renewable Energy Project Development Assistance Non-Disclosure Agreement...

474

Recovery Act: State Assistance for Recovery Act Related Electricity...  

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

Center Recovery Act Recovery Act: State Assistance for Recovery Act Related Electricity Policies Recovery Act: State Assistance for Recovery Act Related Electricity...

475

assisted distal gastrectomy: Topics by E-print Network  

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

of Vermont USA 5. 112000-12312004: Graduate Research Assistant, Department of Civil Engineering, University of Vermont, Vermont, USA III Jacobs, Laurence J. 83 ASSISTED...

476

Fossil Energy Acting Assistant Secretary Recognized at Black...  

Energy Savers [EERE]

the Year Awards February 19, 2013 - 8:54am Addthis Director Dot Harris presents Chris Smith, Principal Deputy Assistant Secretary and Acting Assistant Secretary of Fossil Energy,...

477

USDA Seeks Applications for Grants to Assist Rural Communities...  

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

Seeks Applications for Grants to Assist Rural Communities with Extremely High Energy Costs USDA Seeks Applications for Grants to Assist Rural Communities with Extremely High Energy...

478

U.S. Department of Energy Weatherization Assistance Program Homes...  

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

S. Department of Energy Weatherization Assistance Program Homes Weatherized By State through 06302010 (Calendar Year) U.S. Department of Energy Weatherization Assistance Program...

479

H2-Assisted NOx Traps: Test Cell Results Vehicle Installations...  

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

H2-Assisted NOx Traps: Test Cell Results Vehicle Installations H2-Assisted NOx Traps: Test Cell Results Vehicle Installations 2003 DEER Conference Presentation: ArvinMeritor...

480

Carbon dioxide-assisted fabrication of highly uniform submicron...  

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

dioxide-assisted fabrication of highly uniform submicron-sized colloidal carbon spheres via hydrothermal carbonization Carbon dioxide-assisted fabrication of highly uniform...

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.


481

Sandia National Laboratories: New Mexico Small Business Assistance...  

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

ClimateECEnergyNew Mexico Small Business Assistance (NMSBA) Program Collaborations Recognized New Mexico Small Business Assistance (NMSBA) Program Collaborations Recognized EFRC...

482

New Mexico Small Business Assistance Program recognized by U...  

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

NM Small Business assistance program recognized New Mexico Small Business Assistance Program recognized by U.S. Department of Commerce Receives the 2012 Manufacturing Advocate of...

483

Relationship Between Soil Moisture Storage and Deep Percolation and Subsurface Return Flow  

E-Print Network [OSTI]

A simulation study was performed to analyze the relationship between the volume of moisture stored in a soil profile and the rate of percolation and subsurface return flow. The simulation study was derived on the basis of the Richards equation...

Nieber, J. L.

484

Multiphase flow calculation software  

DOE Patents [OSTI]

Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

Fincke, James R. (Idaho Falls, ID)

2003-04-15T23:59:59.000Z

485

Flow Partitioning in Fully Saturated Soil Aggregates  

SciTech Connect (OSTI)

Microbes play an important role in facilitating organic matter decomposition in soils, which is a major component of the global carbon cycle. Microbial dynamics are intimately coupled to environmental transport processes, which control access to labile organic matter and other nutrients that are needed for the growth and maintenance of microorganisms. Transport of soluble nutrients in the soil system is arguably most strongly impacted by preferential flow pathways in the soil. Since the physical structure of soils can be characterized as being formed from constituent micro aggregates which contain internal porosity, one pressing question is the partitioning of the flow among the inter-aggregate and intra-aggregate pores and how this may impact overall solute transport within heterogeneous soil structures. The answer to this question is particularly important in evaluating assumptions to be used in developing upscaled simulations based on highly-resolved mechanistic models. We constructed a number of diverse multi-aggregate structures with different packing ratios by stacking micro-aggregates containing internal pores and varying the size and shape of inter-aggregate pore spacing between them. We then performed pore-scale flow simulations using computational fluid dynamics methods to determine the flow patterns in these aggregate-of-aggregates structures and computed the partitioning of the flow through intra- and inter-aggregate pores as a function of the spacing between the aggregates. The results of these numerical experiments demonstrate that soluble nutrients are largely transported via flows through inter-aggregate pores. Although this result is consistent with intuition, we have also been able to quantify the relative flow capacity of the two domains under various conditions. For example, in our simulations, the flow capacity through the aggregates (intra-aggregate flow) was less than 2% of the total flow when the spacing between the aggregates was larger than 18 micron. Inter-aggregate pores continued to be the dominant flow pathways even at much smaller spacing; intra-aggregate flow was less than 10% of the total flow when the inter- and intra-aggregate pore sizes were comparable. Such studies are making it possible to identify which model upscaling assumptions are realistic and what computational methods are required for detailed numerical investigation of microbial carbon cycling dynamics in soil systems.

Yang, Xiaofan; Richmond, Marshall C.; Scheibe, Timothy D.; Perkins, William A.; Resat, Haluk

2014-03-30T23:59:59.000Z

486

Real-time state estimation of laboratory flows  

E-Print Network [OSTI]

In this project, we use a real time computer model to simulate a differentially heated laboratory annulus. The laboratory annulus allows us to study chaotic flows typical of the atmosphere. Our objective is to bring the ...

Stransky, Scott (Scott M.)

2007-01-01T23:59:59.000Z

487

Optimized Cross-Slot Flow Geometry for Microfluidic Extensional Rheometry  

E-Print Network [OSTI]

A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. ...

Haward, Simon J.

488

Friction and the oscillatory motion of granular flows  

E-Print Network [OSTI]

This contribution reports on numerical simulations of 2D granular flows on erodible beds. The broad aim is to investigate whether simple flows of model granular matter exhibits spontaneous oscillatory motion in generic flow conditions, and in this case, whether the frictional properties of the contacts between grains may affect the existence or the characteristics of this oscillatory motion. The analysis of different series of simulations show that the flow develops an oscillatory motion with a well-defined frequency which increases like the inverse of the velocity's square root. We show that the oscillation is essentially a surface phenomena. The amplitude of the oscillation is higher for lower volume fractions, and can thus be related to the flow velocity and grains friction properties. The study of the influence of the periodic geometry of the simulation cell shows no significant effect. These results are discussed in relation to sonic sands.

Lydie Staron

2012-11-26T23:59:59.000Z

489

Flow Distances on Open Flow Networks  

E-Print Network [OSTI]

Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...

Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

2015-01-01T23:59:59.000Z

490

Proximal bodies in hypersonic flow  

SciTech Connect (OSTI)

Hypersonic flows involving two or more bodies travelling in close proximity to one another are encountered in several important situations, both natural and man-made. The present work seeks to investigate one aspect of the resulting flow problem by exploring the forces experienced by a secondary body when it is within the domain of influence of a primary body travelling at hypersonic speeds. An analytical methodology based on the blast wave analogy is developed and used to predict the secondary force coefficients for simple geometries in both two and three dimensions. When the secondary body is entirely inside the primary shocked region, the nature of the lateral force coefficient is found to depend strongly on the relative size of the two bodies. For two spheres, the methodology predicts that the secondary body will experience an exclusively attractive lateral force if the secondary diameter is larger than one-sixth the primary diameter. The analytical results are compared with those from numerical simulations and reasonable agreement is observed if an appropriate normalization for the lateral displacement is used. Results from a series of experiments in the T5 hypervelocity shock tunnel are also presented and compared with perfect-gas numerical simulations, with good agreement. A new force-measurement technique for short-duration hypersonic facilities, enabling the experimental simulation of the proximal bodies problem, is described. This technique provides two independent means of measurement, and the agreement observed between the two gives a further degree of confidence in the results obtained.

Deiterding, Ralf [ORNL; Laurence, Stuart J [California Institute of Technology, Pasadena; Hornung, Hans G [California Institute of Technology, Pasadena

2007-01-01T23:59:59.000Z

491

Spectro-polarimetric simulations of the solar limb: absorption-emission FeI $6301.5\\mathrm{\\AA}$ and $6302.5\\mathrm{\\AA}$ line profiles and torsional flows in the intergranular magnetic flux concentrations  

E-Print Network [OSTI]

Using radiative magneto-hydrodynamic simulations of the magnetised solar photosphere and detailed spectro-polarimetric diagnostics with the FeI $6301.5\\mathrm{\\AA}$ and $6302.5\\mathrm{\\AA}$ photospheric lines in the local thermodynamic equilibrium approximation, we model active solar granulation as if it was observed at the solar limb. We analyse general properties of the radiation across the solar limb, such as the continuum and the line core limb darkening and the granulation contrast. We demonstrate the presence of profiles with both emission and absorption features at the simulated solar limb, and pure emission profiles above the limb. These profiles are associated with the regions of strong linear polarisation of the emergent radiation, indicating the influence of the intergranular magnetic fields on the line formation. We analyse physical origins of the emission wings in the Stokes profiles at the limb, and demonstrate that these features are produced by localised heating and torsional motions in the in...

Shelyag, S

2015-01-01T23:59:59.000Z

492

Trivializing maps, the Wilson flow and the HMC algorithm  

E-Print Network [OSTI]

In lattice gauge theory, there exist field transformations that map the theory to the trivial one, where the basic field variables are completely decoupled from one another. Such maps can be constructed systematically by integrating certain flow equations in field space. The construction is worked out in some detail and it is proposed to combine the Wilson flow (which generates approximately trivializing maps for the Wilson gauge action) with the HMC simulation algorithm in order to improve the efficiency of lattice QCD simulations.

Martin Lscher

2009-12-03T23:59:59.000Z

493

Student Success Center Graduate Teaching Assistant ORGANIZATION  

E-Print Network [OSTI]

POSITION: Student Success Center Graduate Teaching Assistant ORGANIZATION: The College of Agricultural Sciences and Natural Resources (CASNR) Student Success Center is a part of CASNR's Academic Programs Office and supports student learning, development, and achievement by providing tools

Veiga, Pedro Manuel Barbosa

494

MATTHEW WRIGHT Assistant Professor, Department of Government  

E-Print Network [OSTI]

MATTHEW WRIGHT Assistant Professor, Department of Government School of Public-REVIEWED (Forth.) Reeskens, T., & Wright, M. "Host Country Patriotism Among European Studies. (Forth.) Citrin, J., Levy, M., & Wright, M. "Multicultural Policy

Lansky, Joshua

495

CC: Security, Residential Life Evacuation Assistance Form  

E-Print Network [OSTI]

CC: Security, Residential Life Evacuation Assistance Form Voluntary Self-Identification If you have will be kept confidential and used only by Environmental Health and Safety, Residential Life (if applicable

Mahon, Bradford Z.

496

ARRA Proposed Award: Energy Technology Assistance Program  

E-Print Network [OSTI]

ARRA Proposed Award: Energy Technology Assistance Program Statewide Program ­ covering Greater Sub contractors: California Lighting Technology Center California Labor Management Cooperation multiplier) Partnering Clean Energy Workforce Training Programs: Sacramento Employment Training Agency

497

Assistance to States on Electric Industry Issues  

SciTech Connect (OSTI)

This project seeks to educate state policymakers through a coordinated approach involving state legislatures, regulators, energy officials, and governors staffs. NCSLs activities in this project focus on educating state legislators. Major components of this proposal include technical assistance to state legislatures, briefing papers, coordination with the National Council on Electricity Policy, information assistance, coordination and outreach, meetings, and a set of transmission-related activities.

Glen Andersen

2010-10-25T23:59:59.000Z

498

Gas flow in barred potentials  

E-Print Network [OSTI]

We use a Cartesian grid to simulate the flow of gas in a barred Galactic potential and investigate the effects of varying the sound speed in the gas and the resolution of the grid. For all sound speeds and resolutions, streamlines closely follow closed orbits at large and small radii. At intermediate radii shocks arise and the streamlines shift between two families of closed orbits. The point at which the shocks appear and the streamlines shift between orbit families depends strongly on sound speed and resolution. For sufficiently large values of these two parameters, the transfer happens at the cusped orbit as hypothesised by Binney et al. over two decades ago. For sufficiently high resolutions the flow downstream of the shocks becomes unsteady. If this unsteadiness is physical, as appears to be the case, it provides a promising explanation for the asymmetry in the observed distribution of CO.

Sormani, Mattia C; Magorrian, John

2015-01-01T23:59:59.000Z

499

Environmentally assisted cracking of LWR materials  

SciTech Connect (OSTI)

Research on environmentally assisted cracking (EAC) of light water reactor materials has focused on (a) fatigue initiation in pressure vessel and piping steels, (b) crack growth in cast duplex and austenitic stainless steels (SSs), (c) irradiation-assisted stress corrosion cracking (IASCC) of austenitic SSs, and (d) EAC in high- nickel alloys. The effect of strain rate during different portions of the loading cycle on fatigue life of carbon and low-alloy steels in 289{degree}C water was determined. Crack growth studies on wrought and cast SSs have been completed. The effect of dissolved-oxygen concentration in high-purity water on IASCC of irradiated Type 304 SS was investigated and trace elements in the steel that increase susceptibility to intergranular cracking were identified. Preliminary results were obtained on crack growth rates of high-nickel alloys in water that contains a wide range of dissolved oxygen and hydrogen concentrations at 289 and 320{degree}C. The program on Environmentally Assisted Cracking of Light Water Reactor Materials is currently focused on four tasks: fatigue initiation in pressure vessel and piping steels, fatigue and environmentally assisted crack growth in cast duplex and austenitic SS, irradiation-assisted stress corrosion cracking of austenitic SSs, and environmentally assisted crack growth in high-nickel alloys. Measurements of corrosion-fatigue crack growth rates (CGRs) of wrought and cast stainless steels has been essentially completed. Recent progress in these areas is outlined in the following sections.

Chopra, O.K.; Chung, H.M.; Kassner, T.F.; Shack, W.J.

1995-12-01T23:59:59.000Z

500

Portable wastewater flow meter  

DOE Patents [OSTI]

A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

1999-02-02T23:59:59.000Z