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Note: This page contains sample records for the topic "axis radiographic hydrodynamic" from the National Library of EnergyBeta (NLEBeta).
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1

Dual Axis Radiographic Hydrodynamic Test Facility | National...  

National Nuclear Security Administration (NNSA)

Dual Axis Radiographic Hydrodynamic Test Facility | National Nuclear Security Administration People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

2

Dual Axis Radiographic Hydrodynamic Test Facility  

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

DARHT Facility: A critical component of stockpile stewardship DARHT Facility: A critical component of stockpile stewardship A new research frontier awaits! Our door is open and we thrive on mutually beneficial partnerships, collaborations that drive innovations and new technologies. April 12, 2012 Dominic Tafoya and Dave Honaberger prepare a refurbished DARHT (Dual Axis Radiographic Hydrotest Facility) 2nd axis accelerator cell for magnetic axis alignment measurements. Contact Group Leader Terry Priestley (505) 665-1330 Email Deputy Group Leader Tim Ferris (505) 665-2179 Email Hydrotests are critical in assessing nuclear weapons in nation's stockpile Dual Axis Radiographic Hydrodynamic Test facility 4:17 How DARHT Works The weapons programs at Los Alamos have one principal mission: ensure the safety, security, and effectiveness of nuclear weapons in our nation's

3

DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility  

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

DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT, supports a critical component of LANL's primary mission: to ensure the safety, security, and effectiveness of nuclear weapons in our nation's stockpile. Los Alamos scientists built DARHT, the world's most powerful x-ray machine, to analyze mockups of nuclear weapons. At the Los Alamos National Laboratory (LANL), the Dual-Axis Radiographic Hydrodynamic Test Facility, or DARHT, supports a critical component of LANL's primary mission: to ensure the safety, security, and effectiveness of nuclear weapons in our nation's stockpile. Los Alamos scientists built DARHT, the world's most powerful x-ray machine, to analyze mockups of nuclear weapons.

4

EIS-0228: Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility  

Broader source: Energy.gov [DOE]

This EIS evaluates the potential environmental impact of a proposal to construct and operate the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL)...

5

E-Print Network 3.0 - axis radiographic hydrodynamic Sample Search...  

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

or radiographs, not only the radius of the prosthesis head... prostheses Polyethylene wear Radiograph Polyethylene cup Linear wear Volumetric wear...

6

Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility  

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

88 88 Federal Register / Vol. 60, No. 199 / Monday, October 16, 1995 / Notices Education, National Assessment Governing Board, Suite 825, 800 North Capitol Street NW., Washington, DC, from 8:30 a.m. to 5 p.m. Roy Truby, Executive Director, National Assessment Governing Board. [FR Doc. 95-25557 Filed 10-13-95; 8:45 am] BILLING CODE 4000-01-M DEPARTMENT OF ENERGY Notice of Certification of the Radiological Condition of the Baker and Williams Warehouses Site, New York, NY, 1991-1993 AGENCY: Office of Environmental Management, Department of Energy (DOE). ACTION: Notice of certification. SUMMARY: The Department has completed remedial action to decontaminate warehouses (Buildings 513-519, 521-527, and 529-535 West 20th Street) in New York, New York, and the certification docket is available.

7

AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF  

SciTech Connect (OSTI)

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2014-11-15T23:59:59.000Z

8

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part III: Hydrodynamics and coupled modelling approaches  

Science Journals Connector (OSTI)

Abstract The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative configurations in this context. Vertical axis wind turbines (VAWTs) are one promising configuration, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess the technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This third article focuses on approaches to develop an efficient coupled model of dynamics (considering aerodynamics, hydrodynamics, structural and mooring line dynamics, and control dynamics) for floating VAWTs, as well as suitable ‘semi-analytical’ hydrodynamic models for this type of coupled dynamics models. Emphasis is also placed on utilising computationally efficient models and programming strategies. A comparison of the various forces acting on a floating VAWT with the three main floating support structure (spar, semi-submersible and tension-leg-platform) is also presented to highlight the relative dominant forces and hence importance of model accuracy representing these forces. Lastly a concise summary covering this series of articles is presented to give the reader an overview of this interdisciplinary research area. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu

2014-01-01T23:59:59.000Z

9

RF generation in the DARHT Axis-II beam dump  

SciTech Connect (OSTI)

We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

10

Behavior patterns of axis deer (Axis axis) in Texas  

E-Print Network [OSTI]

BEHAVIOR PATTERNS OF AXIS DEER (AXIS AXIS) IN TEXAS A Thesis by Eugene Robert Fuchs Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree MASTER OF SCIENCE August 1976 Major... Subject: Wildlife and Fisheries Sciences BEHAVIOR PATTERNS OF AXIS DEER (AXIS AXIS) IN TEXAS A Thesis by Eugene Robert Fuchs Approved as to style and content by: (Chairman of Comm ttee) Head of Department) Member ) ( ember August 1976 ABSTRACT...

Fuchs, Eugene Robert

2012-06-07T23:59:59.000Z

11

Vertical axis wind turbine  

SciTech Connect (OSTI)

Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with the axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of the vertical rotary axis.

Kato, Y.; Seki, K.; Shimizu, Y.

1981-01-27T23:59:59.000Z

12

Unusual Cause of Chest Pain on Radiograph  

E-Print Network [OSTI]

Chest Pain on Radiograph Mauro Gallitelli, MD* Pasquale Defor Correspondence: Mauro Gallitelli, MD, Hospital ‘‘SS.

Gallitelli, Mauro; De Chirico, Pasquale

2011-01-01T23:59:59.000Z

13

SCANNED DARHT.pub  

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

Dual Axis Radiographic Dual Axis Radiographic Hydrodynamic Test Facility DOE/IG-0599 May 2003 Schedule, Cost, and Technical Scope Details of Finding ....................................................................... 1 Recommendations and Comments ........................................... 5 Appendices 1. Objective, Scope, and Methodology ...................................... 7 2. Prior Audit Reports ................................................................. 9 DUAL AXIS RADIOGRAPHIC HYDRODYNAMIC TEST FACILITY TABLE OF CONTENTS Page 1 Background The Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is an experimental facility of the Stockpile Stewardship Program. The facility will provide high-speed, high-resolution flash radiographs to

14

Vertical axis wind turbine  

SciTech Connect (OSTI)

Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.

Kato, Y.; Seki, K.; Shimizu, Y.

1981-01-27T23:59:59.000Z

15

Chemical intensification of dental radiographs  

SciTech Connect (OSTI)

The potential applications of chemical intensification in dental radiography are explored. Three standard photographic intensifiers and three methods designed for radiographic use are evaluated. One of these methods is shown to be capable of reducing radiation dose to one half, without loss of diagnostic quality. Further work is necessary to achieve a system sufficiently practicable to deserve widespread use in routine clinical dental radiography.

Price, C.

1983-04-01T23:59:59.000Z

16

Design of radiographic enhancement systems. Final report  

SciTech Connect (OSTI)

Preliminary specifications and designs are given for two radiographic enhancement systems. The first system is a portable system designed to be carried with EOD teams to enhance the contrast of low-density, low-contrast radiographs made with existing EOD radiographic equipment. The second system contains both image-enhancement and improved radiographic equipment and is designed to be carried aboard commercial or military aircraft in an air-transportable pod. Expected production costs and equipment selection are included.

Hayford, D.T.

1986-09-01T23:59:59.000Z

17

RIS-M-2453 PAST RADIOGRAPHIC SYSTEMS  

E-Print Network [OSTI]

radiographic systems 2 3 Radiographic paper 2 4. Fast X-ray films 2 5. X-ray equipment 3 6. Image quality indicators 3 7. Objects examined 3 8. Radiographic image quality 8.1. Kodak fast systems 8.2. Agfa of fluorometallic intensifying screens toget- her with a special brand of X-ray film. Before accepting either

18

Food habits of axis deer (Axis axis) on the Coastal Plain, Calhoun County, Texas  

E-Print Network [OSTI]

FOOD HABITS OF AXIS DEER (Axis axis) ON THE COASTAL PLAIN, CALHOUN COUNTY, TEXAS A Thesis by JOHN CLARENCE SMITH Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 197l Major Subject: Wildlife Science FOOD HABITS OF AXIS DEER (Axi. s axis) ON THE COASTAL PLAIN, CALHOUN COUNTY, TEXAS A Thesis by JOHN CLARENCE SMITH Approved as to style and content by: (Chairman of Committee) ! (Head...

Smith, John Clarence

2012-06-07T23:59:59.000Z

19

Dynamics of a horizontal cylinder oscillating as a wave energy converter about an off-centred axis  

E-Print Network [OSTI]

The hydrodynamic properties of a horizontal cylinder which is free to pitch about an off-centred axis are studied and used to derive the equations of motion of a wave energy converter which extracts energy from incoming ...

Lucas, Jorge

2011-11-22T23:59:59.000Z

20

4 - Hydrodynamic Lubrication  

Science Journals Connector (OSTI)

Publisher Summary In this chapter the basic principles of hydrodynamic lubrication are discussed. The mechanisms of hydrodynamic film generation and the effects of operating variables such as velocity, temperature, load, design parameters, etc., on the performance of such films are outlined. These are explained using bearings commonly found in many engineering applications as examples. Secondary effects in hydrodynamic lubrication such as viscous heating, compressible and non-Newtonian lubricants, bearing-vibration and deformation are described and their influence on bearing-performance assessed. The complete separation of sliding surfaces by a liquid film under full hydrodynamic lubrication can allow bearings to operate indefinitely without any wear. Any liquid or gas can be used for this form of lubrication, provided that no chemical attack on the bearing occurs. The disadvantage of hydrodynamic lubrication is that a non-zero sliding or “squeeze” velocity is required before load capacity is obtained. Some damage to bearings during starting or stopping is inevitable because of this condition. Vibration induced by hydrodynamic instability may occur during operation at high speeds and this should always be carefully controlled. Despite these deficiencies, hydrodynamic lubrication is the preferred form of lubrication in most bearing systems.

Gwidon W. Stachowiak; Andrew W. Batchelor

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Vertical axis wind turbines  

DOE Patents [OSTI]

A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

Krivcov, Vladimir (Miass, RU); Krivospitski, Vladimir (Miass, RU); Maksimov, Vasili (Miass, RU); Halstead, Richard (Rohnert Park, CA); Grahov, Jurij (Miass, RU)

2011-03-08T23:59:59.000Z

22

4 Hydrodynamic Lubrication  

Science Journals Connector (OSTI)

Publisher Summary This chapter discusses the theory of hydrodynamic lubrication. The chapter demonstrates how a basic property of all liquids, such as viscosity, can be used to produce cheap, reliable bearings that operate with low friction and wear. The mechanisms of hydrodynamic film generation and the effects of operating variables such as velocity, temperature, load, design parameters, etc., on the performance of such films are outlined. This is explained using bearings commonly found in many engineering applications as examples. Secondary effects in hydrodynamic lubrication such as viscous heating, compressible and non-Newtonian lubricants, bearing vibration and deformation is described and their influence on bearing performance is assessed. Like many important scientific principles, chance observation played an important role in the recognition of hydrodynamic action as a basic mechanism of bearing lubrication. The complete separation of sliding surfaces by a liquid film under full hydrodynamic lubrication can allow bearings to operate indefinitely without any wear. Any liquid or gas can be used for this form of lubrication provided that no chemical attack of the bearing occurs. The disadvantage of hydrodynamic lubrication is that a non-zero sliding or “squeeze” velocity is required before load capacity is obtained.

1993-01-01T23:59:59.000Z

23

Radiation recommendation series: administratively required dental radiographs  

SciTech Connect (OSTI)

Administrative requirements for radiographs are found in many segments of the United States health care system. This document presents an FDA radiation recommendation on administratively required dental x-ray examinations. In general, such examinations are not requested to further the patient's dental health, but rather as a means of monitoring claims. However, the administrative use of radiographs that have been taken in the normal course of patient care is usually appropriate, as long as the patient's right to privacy is respected.

Not Available

1981-09-01T23:59:59.000Z

24

Hydrodynamics with Triangle Anomalies  

SciTech Connect (OSTI)

We consider the hydrodynamic regime of theories with quantum anomalies for global currents. We show that a hitherto discarded term in the conserved current is not only allowed by symmetries, but is in fact required by triangle anomalies and the second law of thermodynamics. This term leads to a number of new effects, one of which is chiral separation in a rotating fluid at nonzero chemical potential. The new kinetic coefficients can be expressed, in a unique fashion, through the anomaly coefficients and the equation of state. We briefly discuss the relevance of this new hydrodynamic term for physical situations, including heavy-ion collisions.

Son, Dam T. [Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195-1550 (United States); Surowka, Piotr [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States); Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

2009-11-06T23:59:59.000Z

25

Luminescence from hydrodynamic cavitation  

Science Journals Connector (OSTI)

...higher for monatomic gases than for more complicated...and polyatomic) gases, then the constituent...around 9000K for nitrogen and oxygen, and...ordinary diatomic gases. Only when the gas...hydrodynamic cavitation of water, containing dissolved...pressure. However, the solubility of xenon in water...

2011-01-01T23:59:59.000Z

26

Digital radiographic systems detect boiler tube cracks  

SciTech Connect (OSTI)

Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.

Walker, S. [EPRI, Charlotte, NC (United States)

2008-06-15T23:59:59.000Z

27

Vertical axis wind turbine acoustics  

E-Print Network [OSTI]

Vertical Axis Wind Turbine Acoustics Charlie Pearson Corpus Christi College Cambridge University Engineering Department A thesis submitted for the degree of Doctor of Philosophy September 2013 Declaration Described in this dissertation is work... quickly to changing wind conditions, small- scale vertical axis wind turbines (VAWTs) have been proposed as an efficient solution for deployment in built up areas, where the wind is more gusty in nature. If VAWTs are erected in built up areas...

Pearson, Charlie

2014-04-08T23:59:59.000Z

28

Three-dimensional Numerical Analysis on Blade Response of Vertical Axis Tidal Current Turbine Under Operational Condition  

SciTech Connect (OSTI)

Tidal power as a large-scale renewable source of energy has been receiving significant attention recently because of its advantages over the wind and other renewal energy sources. The technology used to harvest energy from tidal current is called a tidal current turbine. Though some of the principles of wind turbine design are applicable to tidal current turbines, the design of latter ones need additional considerations like cavitation damage, corrosion etc. for the long-term reliability of such turbines. Depending up on the orientation of axis, tidal current turbines can be classified as vertical axis turbines or horizontal axis turbines. Existing studies on the vertical axis tidal current turbine focus more on the hydrodynamic aspects of the turbine rather than the structural aspects. This paper summarizes our recent efforts to study the integrated hydrodynamic and structural aspects of the vertical axis tidal current turbines. After reviewing existing methods in modeling tidal current turbines, we developed a hybrid approach that combines discrete vortex method -finite element method that can simulate the integrated hydrodynamic and structural response of a vertical axis turbine. This hybrid method was initially employed to analyze a typical three-blade vertical axis turbine. The power coefficient was used to evaluate the hydrodynamic performance, and critical deflection was considered to evaluate the structural reliability. A sensitivity analysis was also conducted with various turbine height-to-radius ratios. The results indicate that both the power output and failure probability increase with the turbine height, suggesting a necessity for optimal design. An attempt to optimize a 3-blade vertical axis turbine design with hybrid method yielded a ratio of turbine height to radius (H/R) about 3.0 for reliable maximum power output.

Li, Ye; Karri, Naveen K.; Wang, Qi

2014-04-30T23:59:59.000Z

29

A Radiographic Technique With Heavy Ion Microbeams  

SciTech Connect (OSTI)

In this work, we introduce a new technique to perform densitometric and multielemental analysis of samples at the same time using a simple detector with heavy ion micro-beams. It consists in the simultaneous analysis of X-rays induced in the sample and in a secondary target arranged behind the specimen. The X-rays originated in the secondary target are attenuated when crossing the specimen producing a radiographic image with a monochromatic source.

Muscio, J. [ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); Somacal, H.; Burlon, A. A.; Debray, M. E.; Valda, A. A. [ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina); Kreiner, A. J. [U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina); ECyT, UNSAM, 1650 San Martin, Buenos Aires (Argentina); CONICET (Argentina); Kesque, J. M.; Minsky, D. M. [U.A. Fisica, Laboratorio TANDAR, CNEA, 1650 San Martin, Buenos Aires (Argentina)

2007-02-12T23:59:59.000Z

30

Video enhancement of dental radiographic films  

SciTech Connect (OSTI)

A prototype video image display system, a real-time analog enhancer (RAE), was compared to conventional viewing conditions with the use of nonscreen dental films. When medium optical density films were evaluated, there was no significant difference in the number of radiographic details detected. Conventional viewing conditions allowed perception of more details when dark films were evaluated; however, the RAE unit allowed the perception of more details when light films were viewed.

Van Dis, M.L.; Beck, F.M.; Miles, D.A. (Ohio State Univ., Columbus (USA))

1989-08-01T23:59:59.000Z

31

Two-axis angular effector  

DOE Patents [OSTI]

A new class of coplanar two-axis angular effectors. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation.

Vaughn, Mark R. (Albuquerque, NM); Robinett, III, Rush D. (Tijeras, NM); Phelan, John R. (Albuquerque, NM); Van Zuiden, Don M. (Albuquerque, NM)

1997-01-21T23:59:59.000Z

32

Computational Ship Hydrodynamics MOERI Propeller  

E-Print Network [OSTI]

Computational Ship Hydrodynamics MOERI Propeller This area of research is coordinated by the ship 5415 #12;Fluid-Structure Interaction MOERI Propeller 22 Associate force fluid to structure Associate hydrodynamics problems, like slamming and whipping. The code has recently been applied to wind turbine flows

Kusiak, Andrew

33

Stability of Solutions of Hydrodynamic Equations Describing the Scaling Limit of a Massive Piston in an  

E-Print Network [OSTI]

Stability of Solutions of Hydrodynamic Equations Describing the Scaling Limit of a Massive Piston of a system con- sisting of a massive piston immersed in an ideal gas of point particles in a box. We find of a system consisting of a piston of mass M moving parallel to the x-axis in a cube containing non

Chernov, Nikolai

34

Effects on the Physical Environment (Hydrodynamics, Sediment...  

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

Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water Quality) Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water...

35

Magnetic axis safety factor of finite $\\beta$ spheromaks and transition from spheromaks to toroidal magnetic bubbles  

E-Print Network [OSTI]

The value of the safety factor on the magnetic axis of a finite-beta spheromak is shown to be a function of beta in contrast to what was used in P. M. Bellan, Phys. Plasmas 9, 3050 (2002); this dependence on beta substantially reduces the gradient of the safety factor compared to the previous calculation. The method for generating finite-beta spheromak equilibria is extended to generate equilibria describing toroidal magnetic "bubbles" where the hydrodynamic pressure on the magnetic axis is less than on the toroid surface. This "anti-confinement" configuration can be considered an equilibrium with an inverted beta profile and is relevant to interplanetary magnetic clouds as these clouds have lower hydrodynamic pressure in their interior than on their surface.

Bellan, Paul M

2015-01-01T23:59:59.000Z

36

AXI LLC | Open Energy Information  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » AXI LLC Jump to: navigation, search Name AXI LLC Place Quincy, Massachusetts Zip 02169 Sector Biofuels Product Aims to make commercially feasible strains of algae for fuel production Coordinates 42.2363996°, -71.0200613° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.2363996,"lon":-71.0200613,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

37

Comparison of clinically projected and radiographically optimal implant fixture placement.  

E-Print Network [OSTI]

?? Potential dental implant site assessment is initially determined clinically. Subsequent radiographic assessment also provides information about the quantity of available bone. It was hypothesized… (more)

Vaughn, William Shane

2010-01-01T23:59:59.000Z

38

Radiographic apparatus for photographing entire jaws  

SciTech Connect (OSTI)

This disclosure relates to a dental radiographic apparatus for photographing the entire jaw designed to control the rotation of a rotary arm such that the film surface of a film holder mounted at one end of the rotary arm may rotate and move substantially at equal speed substantially equidistantly along the dental arch and that the X-ray beams irradiated upon the film surface from an X-ray generator mounted at the other end of the arm may fall on the dental arch at any point thereof at right angles with the arch. The apparatus makes it possible to obtain a very clear tomographic picture of a curved plane of the entire jaws, the picture being free of a double image of the teeth, partial change in enlargement ratio of the image obtained, and partial difference in the shade of the image obtained.

Nakano, K.

1985-01-22T23:59:59.000Z

39

Flexible helical-axis stellarator  

DOE Patents [OSTI]

An 1=1 helical winding which spirals about a conventional planar, circular central conductor of a helical-axis stellarator adds a significant degree of flexibility by making it possible to control the rotational transform profile and shear of the magnetic fields confining the plasma in a helical-axis stellarator. The toroidal central conductor links a plurality of toroidal field coils which are separately disposed to follow a helical path around the central conductor in phase with the helical path of the 1=1 winding. This coil configuration produces bean-shaped magnetic flux surfaces which rotate around the central circular conductor in the same manner as the toroidal field generating coils. The additional 1=1 winding provides flexible control of the magnetic field generated by the central conductor to prevent the formation of low-order resonances in the rotational transform profile which can produce break-up of the equilibrium magnetic surfaces. Further, this additional winding can deepen the magnetic well which together with the flexible control provides increased stability.

Harris, Jeffrey H. (Oak Ridge, TN); Hender, Timothy C. (Abingdon, GB2); Carreras, Benjamin A. (Oak Ridge, TN); Cantrell, Jack L. (Oak Ridge, TN); Morris, Robert N. (Oak Ridge, TN)

1988-01-01T23:59:59.000Z

40

Group-invariant solutions of hydrodynamics and radiation hydrodynamics  

SciTech Connect (OSTI)

Using the property of invariance under Lie groups of transformations, the equations of hydrodynamics are transformed from partial differential equations to ordinary differential equations, for which special analytic solutions can be found. These particular solutions can be used for (1) numerical benchmarks, (2) the basis for analytic models, and (3) insight into more general solutions. Additionally, group transformations can be used to construct new solutions from existing ones. A space-time projective group is used to generate complicated solutions from simpler solutions. Discussion of these procedures is presented along with examples of analytic of 1,2 and 3-D hydrodynamics.

Coggeshall, S.V.

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Development and Test Plans for a small Vertical Axis Turbine Designed and  

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

Development and Test Plans for a small Vertical Axis Turbine Designed and Development and Test Plans for a small Vertical Axis Turbine Designed and Built by the Russian State Rocket Center under Berkeley Lab auspices Speaker(s): Anthony Radspieler Jr. Glen Dahlbacka Joseph Rasson Date: March 4, 2010 - 12:00pm Location: 90-3122 Berkeley Lab Engineering Division teamed with Empire Magnetics, Rohnert Park and the Makeyev State Rocket Center under a DOE NNSA non-proliferation project to develop and test a series of small wind turbines of vertical axis design. Over the years, about 100 Russian scientists and engineers worked on the project and the hydrodynamic, aerodynamic and mechanical test facilities of the SRC were used. The objective was to create a highly manufacturable Darieus unit with a modest Tip Speed Ratio (quiet and low

42

E-Print Network 3.0 - age radiographic severity Sample Search...  

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

given radiograph... with the metaphysis is a good indicator of skeletal age. Once the atlas image that most resembles the radiograph... . When the physician is sure that the...

43

Hydrodynamic Description of Protein Folding  

Science Journals Connector (OSTI)

A hydrodynamic description of protein folding is proposed and illustrated with a lattice protein model, which has a free energy surface (FES) typical of proteins with two-state folding kinetics. The flows from the unfolded to the native state are concentrated in a limited region of the FES. The rest is occupied by a flow “vortex”, which does not lead to the native state. In contrast with intermediates that are associated with local minima, the vortex is not visible on the FES. The hydrodynamic interpretation thus provides new insights into the mechanism of protein folding and can be a useful complement to standard analyses.

Sergei F. Chekmarev; Andrey Yu. Palyanov; Martin Karplus

2008-01-11T23:59:59.000Z

44

A proposed benchmark for simulation in radiographic testing  

SciTech Connect (OSTI)

The purpose of this benchmark study is to compare simulation results predicted by various models of radiographic testing, in particular those that are capable of separately predicting primary and scatter radiation for specimens of arbitrary geometry.

Jaenisch, G.-R.; Deresch, A.; Bellon, C. [Federal Institute for Materials Research and Testing Unter den Eichen 87, 12205 Berlin (Germany); Schumm, A.; Guerin, P. [EDF R and D, 1 avenue du Général de Gaulle, 92141 Clamart (France)

2014-02-18T23:59:59.000Z

45

Helical axis stellarator with noninterlocking planar coils  

DOE Patents [OSTI]

A helical axis stellarator using only noninterlocking planar, non-circular coils, generates magnetic fields having a magnetic well and large rotational transform with resultant large equilibrium beta.

Reiman, Allan (Princeton, NJ); Boozer, Allen H. (Rocky Hill, NJ)

1987-01-01T23:59:59.000Z

46

Foundation of Hydrodynamics of Strongly Interacting Systems  

E-Print Network [OSTI]

Hydrodynamics and quantum mechanics have many elements in common, as the density field and velocity fields are common variables that can be constructed in both descriptions. Starting with the Schroedinger equation and the Klein-Gordon for a single particle in hydrodynamical form, we examine the basic assumptions under which a quantum system of particles interacting through their mean fields can be described by hydrodynamics.

Cheuk-Yin Wong

2014-04-03T23:59:59.000Z

47

Vertical Axis Wind Turbine Foundation parameter study  

SciTech Connect (OSTI)

The dynamic failure criterion governing the dimensions of prototype Vertical Axis Wind Turbine Foundations is treated as a variable parameter. The resulting change in foundation dimensions and costs is examined.

Lodde, P.F.

1980-07-01T23:59:59.000Z

48

Automatic 5-axis NC toolpath generation  

E-Print Network [OSTI]

Despite over a decade of research, automatic toolpath generation has remained an elusive goal for 5-axis NC machining. This thesis describes the theoretical and practical issues associated with generating collision free ...

Balasubramaniam, Mahadevan, 1976-

2001-01-01T23:59:59.000Z

49

Disruptive Innovation in Numerical Hydrodynamics  

SciTech Connect (OSTI)

We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.

Waltz, Jacob I. [Los Alamos National Laboratory

2012-09-06T23:59:59.000Z

50

Revisiting spherically symmetric relativistic hydrodynamics  

E-Print Network [OSTI]

In this paper we revise two classical examples of Relativistic Hydrodynamics in order to illustrate in detail the numerical methods commonly used in fluid dynamics, specifically those designed to deal with shocks, which are based on a finite volume approximation. The two cases we consider are the relativistic blast wave problem and the evolution of a Tolman-Oppenheimer-Volkoff star model, in spherical symmetry. In the first case we illustrate the implementation of relativistic Euler's equations on a fixed background space-time, whereas in the second case we also show how to couple the evolution of the fluid to the evolution of the space-time.

F. S. Guzman; F. D. Lora-Clavijo; M. D. Morales

2012-12-06T23:59:59.000Z

51

Sandia National Laboratories: Innovative Offshore Vertical-Axis...  

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

WindInnovative Offshore Vertical-Axis Wind Turbine Rotors Innovative Offshore Vertical-Axis Wind Turbine Rotors This project seeks to advance large offshore vertical-axis wind...

52

Hydrodynamic Modeling and the QGP Shear Viscosity  

E-Print Network [OSTI]

In this article, we will briefly review the recent progress on hydrodynamic modeling and the extraction of the quark-gluon plasma (QGP) specific shear viscosity with an emphasis on results obtained from the hybrid model VISHNU that couples viscous hydrodynamics for the macroscopic expansion of the QGP to the hadron cascade model for the microscopic evolution of the late hadronic stage.

Huichao Song

2012-07-10T23:59:59.000Z

53

RELIABLE RADIOGRAPHIC INSPECTION OF FLEXIBLE RISERS FOR THE OIL INDUSTRY  

SciTech Connect (OSTI)

Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.

Almeida, Romulo M.; Rebello, Joao Marcos A. [Department of Metallurgical and Materials Engineering COPPE/UFRJ-Federal University of Rio de Janeiro P.O. Box 68505 CEP 21941-972, Rio de Janeiro RJ (Brazil); Vaz, Murilo A. [Department of Ocean Engineering-COPPE/UFRJ (Brazil)

2010-02-22T23:59:59.000Z

54

Registration of Planar Film Radiographs with Computed Tomography  

E-Print Network [OSTI]

Registration of Planar Film Radiographs with Computed Tomography Lisa M. Gottesfeld Brown lisabHigh University Bethlehem, PA 18015 Abstract In this paper we describe a method to register Computed Tomography, high resolution, three dimensional, structural med- ical images, such as data from X-ray computed

Boult, Terrance E.

55

Hydrodynamic Testing Facilities Database | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamic Testing Facilities Database Hydrodynamic Testing Facilities Database (Redirected from Hydrodynamic Testing Facilities) Jump to: navigation, search Facility Operators By viewing Hydrodynamic Testing Facilities in the list accompanying the map, one will be provided with data on a range of test capabilities and services available at commercial, academic, and government facilities and offshore berths within the United States. Click on a thumbnail in the adjacent map in order to view a testing facility operator's profile page. This page will include in depth information about the testing facilities that each operator oversees. Click on this link, CSV ,to download all of the information on all hydrodynamic testing facilities. Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":5000,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

56

T-613: Microsoft Excel Axis Properties Remote Code Execution...  

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

3: Microsoft Excel Axis Properties Remote Code Execution Vulnerability T-613: Microsoft Excel Axis Properties Remote Code Execution Vulnerability May 2, 2011 - 7:42am Addthis...

57

Solasta aka The Eagle Axis | Open Energy Information  

Open Energy Info (EERE)

Eagle Axis Jump to: navigation, search Name: Solasta (aka The Eagle Axis) Place: Newton, Massachusetts Zip: 2458 Sector: Efficiency, Solar Product: Start-up planning to produce...

58

Effects on the Physical Environment (Hydrodynamics, and Water...  

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

Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web) Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web) Effects on the...

59

UCRL-CONF-212699 Hydrodynamic  

National Nuclear Security Administration (NNSA)

CONF-212699 CONF-212699 Hydrodynamic test problems B. Moran June 6, 2005 Five Lab Conference Vienna, Austria June 20, 2005 through June 24, 2005 Disclaimer This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United

60

Detonation waves in relativistic hydrodynamics  

Science Journals Connector (OSTI)

This paper is concerned with an algebraic study of the equations of detonation waves in relativistic hydrodynamics taking into account the pressure and the energy of thermal radiation. A new approach to shock and detonation wavefronts is outlined. The fluid under consideration is assumed to be perfect (nonviscous and nonconducting) and to obey the following equation of state: p=(?-1)? where p, ?, and ? are the pressure, the total energy density, and the adiabatic index, respectively. The solutions of the equations of detonation waves are reduced to the problem of finding physically acceptable roots of a quadratic polynomial ?(X) where X is the ratio ?/?0 of dynamical volumes behind and ahead of the detonation wave. The existence and the locations of zeros of this polynomial allow it to be shown that if the equation of state of the burnt fluid is known then the variables characterizing the unburnt fluid obey well-defined physical relations.

Mahdy Cissoko

1992-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Hydrodynamics of vibrated granular monolayer.  

SciTech Connect (OSTI)

We investigate the long-standing puzzle of phase separation in a granular monolayer vibrated from below. Although this system is three dimensional, an interesting dynamics occurs mostly in the horizontal plane, perpendicular to the direction of vibration. Experiments [Olafsen and Urbach, Phys. Rev. Lett. 81 4369 (1998)] demonstrated that for a high amplitude of vibration the system is in the gaslike phase, but when the amplitude becomes smaller than a certain threshold, a phase separation occurs: A solidlike dense condensate of particles forms in the center of the system, surrounded by particles in the gaslike phase. We explain theoretically the experimentally observed coexistence of dilute and dense phases, employing Navier-Stokes granular hydrodynamics. We show that the phase separation is associated with a negative compressibility of granular gas.

Khain, E.; Aranson, I. S. (Materials Science Division); (Oakland Univ.)

2011-01-01T23:59:59.000Z

62

Axis Technologies Group Inc | Open Energy Information  

Open Energy Info (EERE)

Axis Technologies Group Inc Axis Technologies Group Inc Jump to: navigation, search Name Axis Technologies Group, Inc Place Lincoln, Nebraska Zip 68522 Product Designs, manufactures, and markets energy-saving and daylight harvesting electronic dimming ballasts for the commercial lighting industry. Coordinates 47.829403°, -118.419202° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":47.829403,"lon":-118.419202,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

63

Enclosed, off-axis solar concentrator  

DOE Patents [OSTI]

A solar concentrator including a housing having receiving wall, a reflecting wall and at least two end walls, the receiving, reflecting and end walls defining a three-dimensional volume having an inlet, wherein a vertical axis of the housing is generally perpendicular to the inlet, a receiver mounted on the receiving wall of the housing, the receiver including at least one photovoltaic cell, wherein a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, at least one clip disposed on the reflecting wall an optical element received within the three-dimensional volume, the optical element including at least one tab, the tab being engaged by the clip to align the optical element with the receiver, and a window received over the inlet to enclose the housing.

Benitez, Pablo; Grip, Robert E; Minano, Juan C; Narayanan, Authi A; Plesniak, Adam; Schwartz, Joel A

2013-11-26T23:59:59.000Z

64

Non abelian hydrodynamics and heavy ion collisions  

SciTech Connect (OSTI)

The goal of the relativistic heavy ion collisions (RHIC) program is to create a state of matter where color degrees of freedom are deconfined. The dynamics of matter in this state, in spite of the complexities of quantum chromodynamics, is largely determined by the conservation laws of energy momentum and color currents. Therefore it is possible to describe its main features in hydrodynamic terms, the very short color neutralization time notwithstanding. In this lecture we shall give a simple derivation of the hydrodynamics of a color charged fluid, by generalizing the usual derivation of hydrodynamics from kinetic theory to the non abelian case.

Calzetta, E. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina)

2014-01-14T23:59:59.000Z

65

A low order model for vertical axis wind turbines  

E-Print Network [OSTI]

A new computational model for initial sizing and performance prediction of vertical axis wind turbines

Drela, Mark

66

Hydrodynamic properties of carbon nanotubes  

Science Journals Connector (OSTI)

We study water flowing past an array of single walled carbon nanotubes using nonequilibrium molecular dynamics simulations. For carbon nanotubes mounted with a tube spacing of 16.4×16.4 nm and diameters of 1.25 and 2.50 nm, respectively, we find drag coefficients in reasonable agreement with the macroscopic, Stokes-Oseen solution. The slip length is -0.11 nm for the 1.25 nm carbon nanotube, and 0.49 for the 2.50 nm tube for a flow speed of 50 m/s, respectively, and 0.28 nm for the 2.50 nm tube at 200 m/s. A slanted flow configuration with a stream- and spanwise velocity component of 100 ms-1 recovers the two-dimensional results, but exhibits a significant 88 nm slip along the axis of the tube. These results indicate that slip depends on the particular flow configuration.

J. H. Walther; T. Werder; R. L. Jaffe; P. Koumoutsakos

2004-06-04T23:59:59.000Z

67

Hydrodynamic Testing Facilities Database | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamic Testing Facilities Database Hydrodynamic Testing Facilities Database Jump to: navigation, search Facility Operators By viewing Hydrodynamic Testing Facilities in the list accompanying the map, one will be provided with data on a range of test capabilities and services available at commercial, academic, and government facilities and offshore berths within the United States. Click on a thumbnail in the adjacent map in order to view a testing facility operator's profile page. This page will include in depth information about the testing facilities that each operator oversees. Click on this link, CSV ,to download all of the information on all hydrodynamic testing facilities. Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":5000,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

68

Vortex lines and transitions in superfluid hydrodynamics  

Science Journals Connector (OSTI)

...Preface to Vortices, dislocations, and line singularities in partial differential equations...Leslie and J. R. Ockendon. Vortex lines and transitions in superfluid hydrodynamics...nature and the motion of qunatized vortex lines. This paper illustrates the transitions...

1997-01-01T23:59:59.000Z

69

A benchmark concept for simulation in radiographic testing  

SciTech Connect (OSTI)

The new standard ISO 17636–2:2013 “NDT of welds: Radiographic testing - Part 2: X- and gamma ray techniques with digital detectors” describes a complex procedure for film replacement by phosphor imaging plates and digital detector arrays. RT modeling software should consider these detector types, X-ray film, and the standard requirements for image quality. Practitioners expect the same visibility of image quality indicators (IQI) in the simulated radiographs as in the experimental exposures. The proposed benchmark test is based on the comparison of experimental radiographs taken at BAM with modeled ones of participants. The experimental setup and the determination of the equivalent penetrameter sensitivity (EPS) as described in the procedure of ASTM E 746 are used for quantitative evaluation of the achievable contrast sensitivity for step hole IQIs as considered in Annex B of ISO 17636–2. System classification data for Computed Radiography (CR) and film systems will be provided by BAM according to ISO 11699–1 for selected film systems and according to ASTM E 2446 for selected CR systems. The classification of films and digital detectors is based on the measurement of the dose response function, the basic spatial resolution (SR{sub b}) of the image, and the measured image noise, which depends on the detector efficiency, the quantum statistics, and the detector fixed pattern noise.

Ewert, U.; Deresch, A.; Bellon, C.; Jaenisch, G.-R. [Federal Institute for Materials Research and Testing Unter den Eichen 87, 12205 Berlin (Germany)

2014-02-18T23:59:59.000Z

70

Compliance of Michigan dentists with radiographic safety recommendations  

SciTech Connect (OSTI)

We surveyed a random sample of 398 Michigan dentists in private practice to determine their compliance with the American Dental Association Council's recommendations for radiographic equipment and techniques. The response rate was 67% of the questionnaires delivered successfully. The majority of dentists use only D-speed film (73%) and round collimation of the x-ray beam (90%). Only 5% have an x-ray machine equipped with a rectangular collimator and 18% have at least one machine with a pointed cone. Leaded apron use is almost universal, but only 49% of the dentists use cervical collars in addition to the apron. The majority of dentists surveyed do not comply with the American Dental Association Council's recommendations on film speed, collimation, and use of leaded cervical collar. Using effective dose equivalents determined by Gibbs et al. for a variety of radiographic techniques, we estimate that an eight-fold reduction in radiation dose could be achieved without eliminating a single radiograph if all dentists used E-speed film and collimation of the beam to the size of the film.

Nakfoor, C.A.; Brooks, S.L. (University of Michigan School of Dentistry, Ann Arbor (United States))

1992-04-01T23:59:59.000Z

71

Proton Radiography at LANL | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

present state-of-the-art hydrotest facility is the Dual-Axis Radiographic Hydrodynamic Test facility, or DARHT. Recently completed at Los Alamos, DARHT is expected to be the...

72

Development and Verification of a Computational Fluid Dynamics Model of a Horizontal-Axis Tidal Current Turbine  

SciTech Connect (OSTI)

This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.

Lawson, M. J.; Li, Y.; Sale, D. C.

2011-10-01T23:59:59.000Z

73

High payload six-axis load sensor  

DOE Patents [OSTI]

A repairable high-payload six-axis load sensor includes a table, a base, and at least three shear-pin load transducers removably mounted between the table and the base. Removable mounting permits easy replacement of damaged shear pins. Preferably, the shear-pin load transducers are responsive to shear forces imparted along the two axes perpendicular to an axis of minimum sensitivity characteristic of the transducer. Responsive to an applied shear force, each shear-pin load transducer can produce an electrical signal proportional to the reaction force. The load sensor can further include a structure for receiving the proportional electrical signals and computing the applied load corresponding to the proportional electrical signals. The computed load can be expressed in terms of a three-dimensional XYZ Cartesian coordinate system.

Jansen, John F. (Knoxville, TN); Lind, Randall F. (Knoxville, TN)

2003-01-01T23:59:59.000Z

74

70template.factsheets.indd  

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

DARHT DARHT Dual-Axis Radiographic Hydrodynamic Test Facility At the Los Alamos National Laboratory (LANL), the Dual-Axis Radiographic Hydrodynamic Test Facility, or DARHT, supports a critical component of LANL's primary mission: to ensure the safety, security, and effectiveness of nuclear weapons in our na- tion's stockpile. Los Alamos scientists built DARHT, the world's most powerful x-ray machine, to analyze mockups of nuclear

75

Space variations in axis height of the jet stream core  

E-Print Network [OSTI]

height of the jet axis relative to the height of the jet maximum for slow vs. fast cases. 13 Mean height of the jet axis relative to the height at the trough. 13 Mean height of the jet axis relative to the height at the ridge. 15 Mean height... of the jet axis relative to the height at the jet maximum, when the maximum is near a trough. 15 Mean height of the jet axis relative to the height at the minimum, when the minimum is near a ridge. 17 Mean height of the jet axis relative to the height...

Leutwyler, Cooke Hearon

1965-01-01T23:59:59.000Z

76

Effect of eliminating administrative radiographs on patient exposure and accuracy of provisional treatment plans  

SciTech Connect (OSTI)

Published reports and recommendations suggest that radiographs are often ordered because of administrative policies during the screening and selection of patients for dental school clinics. This study examined the prescription of radiographs for two groups of patients: those who were radiographically examined according to an administrative policy and those whose radiographic needs were determined by a clinical examination. The provisional treatment needs assessment based on the screening examination was compared to the final treatment plan based on a complete diagnostic workup for both groups of patients to assess the effect of a change in school policy. Clinicians ordered half the number of panoramic radiographs as would have been ordered by administrative policy. There was no significant difference in the agreement between the provisional and final treatment plans under the two policies. These results suggest that dental schools can comply with federal recommendations against administrative radiographs without compromising patient selection.

Kantor, M.L.; Slome, B.A.

1987-12-01T23:59:59.000Z

77

Multi-axis Capability for Powered Ankle-Foot Prostheses  

Science Journals Connector (OSTI)

In this chapter, the concept of a multi-axis powered ankle-foot prosthesis is introduced. The feasibility of this ... proposed cable-driven mechanism for the multi-axis powered ankle-foot prosthesis is capable of...

Evandro M. Ficanha; Mohammad Rastgaar; Kenton R. Kaufman

2014-01-01T23:59:59.000Z

78

Vertical axis wind turbine with continuous blade angle adjustment  

E-Print Network [OSTI]

The author presents a concept for a vertical axis wind turbine that utilizes each blade's entire rotational cycle for power generation. Each blade has its own vertical axis of rotation and is constrained to rotate at the ...

Weiss, Samuel Bruce

2010-01-01T23:59:59.000Z

79

E-Print Network 3.0 - ap radiographs including Sample Search...  

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

Information Sciences 5 Eccentricity Error Correction for Automated Estimation of Polyethylene Wear after Total Hip Arthroplasty Summary: in an anteroposterior (AP) radiograph....

80

Dental radiographic exposure normalization program (DENT). The experience in Nassau County, NY  

SciTech Connect (OSTI)

A Federally sponsored program for reducing unnecessary exposures from dental radiographic procedures is monitored over four years. The results are encouraging.

Goren, A.D.; Sciubba, J.J.; Moskowitz, G.W.; Mehta, S.; Theesfeld, R.L.

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Colorado State University Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamics Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Colorado State University Address Daryl B. Simons Building, Engineering Research Center, 1320 Campus Delivery Place Fort Collins, Colorado Zip 80523 Phone number (970) 491-8394 Website http://www.hydraulicslab.engr. Coordinates 40.575727216126°, -105.0833302192° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.575727216126,"lon":-105.0833302192,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

82

University of Maine Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamics Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of Maine Address 208 Boardman Hall Place Orono, Maine Zip 04469 Sector Hydro Phone number (207) 581-2129 Website http://gradcatalog.umaine.edu/ Coordinates 44.9024546°, -68.6638413° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.9024546,"lon":-68.6638413,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

83

University of Michigan Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamics Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of Michigan Address 1085 South University Avenue Place Ann Arbor, Michigan Zip 48109 Sector Hydro Phone number (734) 764-9432 Website http://www.engin.umich.edu/dep Coordinates 42.2757556°, -83.7362041° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.2757556,"lon":-83.7362041,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

84

Pennsylvania State University Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

State University Hydrodynamics State University Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Pennsylvania State University Address Applied Research Laboratory, Garfield Thomas Water Tunnel, PO Box 30 Place State College, Pennsylvania Zip 16804 Sector Hydro Phone number (814) 865-1741 Website http://www.arl.psu.edu/facilit Coordinates 40.7919761°, -77.8608811° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.7919761,"lon":-77.8608811,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

85

Oregon State University Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Oregon State University Hydrodynamics Oregon State University Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Oregon State University Address O.H. Hinsdale Wave Research Laboratory, 220 Owen Hall Place Corvallis, Oregon Zip 97331 Sector Hydro Phone number (541) 737-3631 Website http://wave.oregonstate.edu Coordinates 44.5642722°, -123.2785942° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.5642722,"lon":-123.2785942,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

86

University of Minnesota Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamics Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of Minnesota Address St. Anthony Falls Laboratory, 2 Third Avenue SE Place Minneapolis, MN Zip 55414 Sector Hydro Phone number (612) 624-4363 Website http://www.safl.umn.edu/ Coordinates 44.9824832°, -93.2550859° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.9824832,"lon":-93.2550859,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

87

Sandia National Laboratories Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Laboratories Hydrodynamics Laboratories Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Sandia National Laboratories Address P.O. Box 5800 Place Albuquerque, NM Zip 87185 Sector Hydro Website http://www.sandia.gov/vqsec/SO Coordinates 34.9799999°, -106.52° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":34.9799999,"lon":-106.52,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

88

Massachusetts Institute of Technology Hydrodynamics | Open Energy  

Open Energy Info (EERE)

Massachusetts Institute of Technology Hydrodynamics Massachusetts Institute of Technology Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Massachusetts Institute of Technology Address 77 Massachusetts Avenue Place Cambridge, Massachusetts Zip 02139 Sector Hydro Phone number (617) 254-4348 Website http://web.mit.edu/towtank/www Coordinates 42.3597807°, -71.0936091° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.3597807,"lon":-71.0936091,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

89

Experimental research on tidal current vertical axis turbine with variable-pitch blades  

Science Journals Connector (OSTI)

Abstract Due to the limited storage and ever-increasing dependence on fossil fuel, the world is in the phase of shifting toward renewable energy. Tidal current energy is one of the most predictable forms of renewable energy, which is harnessed by utilizing a tidal current turbine. To study the performance of the tidal current turbine relating to the ability of energy absorption and exchanging, experimental tests play an important role which can not only validate the numerical results but also provide a reference for the prototype design. In this study, a series of experiments related to vertical-axis turbines (VAT) were carried out at Harbin Engineering University and a large quantity of experimental data to study the hydrodynamic performance of turbines was presented. Based on the different techniques used to control the pitch mechanism, the experiments can be classified as the cycloid type controllable-pitch, spring-control pitch and passive variable-pitch VAT experiment. The influences of the different parameters on the hydrodynamic performance of turbines were discussed. Finally, some control strategies for the blade for different turbines were given.

Fengmei Jing; Qihu Sheng; Liang Zhang

2014-01-01T23:59:59.000Z

90

Ship capsizing analysis using advanced hydrodynamic modelling  

Science Journals Connector (OSTI)

...hydrodynamic forces due to radiation and di raction is based...nonlinear dependence of the radiation/di raction forces...switching between the radiation coe cients (see x 5...viding us with the software Simbel, and R. Pereira...International Convention for the Safety of Life at Sea, 1974...

2000-01-01T23:59:59.000Z

91

(Non)-Dissipative Hydrodynamics on Embedded Surfaces  

E-Print Network [OSTI]

We construct the theory of dissipative hydrodynamics of uncharged fluids living on embedded space-time surfaces to first order in a derivative expansion in the case of codimension-1 surfaces (including fluid membranes) and the theory of non-dissipative hydrodynamics to second order in a derivative expansion in the case of codimension higher than one under the assumption of no angular momenta in transverse directions to the surface. This construction includes the elastic degrees of freedom, and hence the corresponding transport coefficients, that take into account transverse fluctuations of the geometry where the fluid lives. Requiring the second law of thermodynamics to be satisfied leads us to conclude that in the case of codimension-1 surfaces the stress-energy tensor is characterized by 2 hydrodynamic and 1 elastic independent transport coefficient to first order in the expansion while for codimension higher than one, and for non-dissipative flows, the stress-energy tensor is characterized by 7 hydrodynamic and 3 elastic independent transport coefficients to second order in the expansion. Furthermore, the constraints imposed between the stress-energy tensor, the bending moment and the entropy current of the fluid by these extra non-dissipative contributions are fully captured by equilibrium partition functions. This analysis constrains the Young modulus which can be measured from gravity by elastically perturbing black branes.

Jay Armas

2014-09-17T23:59:59.000Z

92

HYDRODYNAMIC ISSUES IN PAMS MANDREL TARGET FABRICATION  

SciTech Connect (OSTI)

OAK-B135 Imperfections in PAMS mandrels critically govern the quality of final ICF targets. Imperfections in the mandrels can have a wide range of origins. Here, they present observations of 3 types of imperfections, and data to support the proposal that hydrodynamic factors during the curing of the mandrel are potential causes of these imperfections.

McQUILLAN,B.W; PAGUIO,R; SUBRAMANIAN,P; TAKAGI,M; ZEBIB,A

2003-09-01T23:59:59.000Z

93

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

Johnson, Kenneth C. (201 W. California Ave. #705, Sunnyvale, CA 94086)

1992-01-01T23:59:59.000Z

94

Vertical axis wind turbine control strategy  

SciTech Connect (OSTI)

Early expensive in automatic operation of the Sandia 17-m vertical axis research wind turbine (VAWT) has demonstrated the need for a systematic study of control algorithms. To this end, a computer model has been developed that uses actual wind time series and turbine performance data to calculate the power produced by the Sandia 17-m VAWT operating in automatic control. The model has been used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long-term energy production. An attempt has been made to generalize these results from local site and turbine characteristics to obtain general guidelines for control algorithm design.

McNerney, G.M.

1981-08-01T23:59:59.000Z

95

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion. 16 figs.

Johnson, K.C.

1992-12-08T23:59:59.000Z

96

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

Johnson, Kenneth C. (201 W. California Ave., #401, Sunnyvale, CA 94086)

1990-01-01T23:59:59.000Z

97

A comparison of on-axis and off-axis heliostat alignment strategies  

SciTech Connect (OSTI)

Heliostat installation and alignment costs will be an important element in future solar power tower projects. The predicted annual performances of on- and-off axis strategies are compared for 95 m{sup 2} flat-glass heliostats and an external, molten-salt receiver. Actual approaches to heliostat alignment that have been used in the past are briefly discussed, and relative strengths and limitations are noted. The optimal approach can vary with the application.

Jones, S.A.

1996-03-01T23:59:59.000Z

98

LANL | Physics | Hydrodynamic Material Instabilities at extremes  

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

Understanding hydrodynamic material instabilities at extremes Understanding hydrodynamic material instabilities at extremes The National Nuclear Security Administration science-based stockpile stewardship program funds research that will improve critical physics-based dynamic materials models. Los Alamos National Laboratory and Lawrence Livermore National Laboratory, as nuclear weapon design laboratories, are mandated to predict the reliability and durability of the nuclear weapons stockpile. This is done using state-of-the-art supercomputers and computer codes. It is also important to have state-of-the-art physics models in these codes. Los Alamos has theory experts in dynamic materials, thus creating powerful working groups when combined with experimental experts in Physics Division and elsewhere. Key to the science-based stockpile stewardship program is making

99

E-Print Network 3.0 - axis factoring method Sample Search Results  

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

Once this is done, we can call the setup method to properly initialize the axis... On: color values start end moveBy scaleFactor minValue maxValue AbstractAxis AxisAxisDecorator...

100

Quantum Control of Molecular Gas Hydrodynamics  

E-Print Network [OSTI]

We demonstrate that strong impulsive gas heating or heating suppression at standard temperature and pressure can occur from coherent rotational excitation or de-excitation of molecular gases using a sequence of non-ionizing laser pulses. For the case of excitation, subsequent collisional decoherence of the ensemble leads to gas heating significantly exceeding that from plasma absorption under the same laser focusing conditions. In both cases, the macroscopic hydrodynamics of the gas can be finely controlled with ~40 fs temporal sensitivity.

Zahedpour, Sina; Milchberg, Howard

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Cornell University Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

University Hydrodynamics University Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Cornell University Address DeFrees Hydraulics Laboratory, School of Civil and Environmental Engineering, 2B20 Hollister Place Ithaca, New York Zip 14853 Sector Hydro Phone number (607) 255-5140 Website http://www.cee.cornell.edu/abo Coordinates 42.4467049°, -76.4830579° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.4467049,"lon":-76.4830579,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

102

Event Rates for Off Axis NuMI Experiments  

E-Print Network [OSTI]

Neutrino interaction rates for experiments placed off axis in the NuMI beam are calculated. Primary proton beam energy is 120 GeV and four locations at 810 km from target and 6, 12, 30 and 40 km off axis are considered. This report is part of the Joint FNAL/BNL Future Long Baseline Neutrino Oscillation Experiment Study.

B. Viren

2006-08-25T23:59:59.000Z

103

Radiographic Technique for Densitometric Studies Using Heavy Ion Microbeams  

SciTech Connect (OSTI)

Different analytical techniques are typically used to perform multi-elemental and densitometric analysis by means of particle beams with micrometric space resolution. Usually, those analyses are respectively performed by PIXE and STIM. Traditionally, to characterize the trace element concentrations in a specimen two different experiments are required with differences in setups and types of detectors employed, as well as in the necessary ion current intensities. In this work, we discuss the latest results in the development of a new technique that synthesizes both analyses in just a single one, by means of heavy ion induced x-ray emission. This technique, implemented for the first time at the Tandar Laboratory, employs a second target in addition to the sample under study. The multi-elemental information of the specimen is provided by its PIXE signal and its densitometric information is supplied by the PIXE signal of the secondary target, which is placed immediately behind the sample under analysis. These PIXE signals are produced and acquired during the same experiment, allowing the analysis of both features (composition and density) at the same time. The X-rays originated in the secondary target are attenuated when traversing the specimen in the direction of the detector and consequently a radiographic image of the specimen is obtained. In this case, the characteristic X-rays of the secondary target act like a monochromatic secondary source. In the present work, a method to estimate the thickness of specimens is introduced and compared with estimations performed by the STIM method.

Muscio, J. [Escuela de Ciencia y Tecnologia-Universidad Nacional de San Martin (UNSAM) (Argentina); Somacal, H.; Burlon, A. A.; Debray, M. E.; Valda, A. A. [Escuela de Ciencia y Tecnologia-Universidad Nacional de San Martin (UNSAM) (Argentina); Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA) (Argentina); Kreiner, A. J. [Escuela de Ciencia y Tecnologia-Universidad Nacional de San Martin (UNSAM) (Argentina); Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA) (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Kesque, J. M.; Minsky, D. M. [Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA) (Argentina); Davidson, M.; Davidson, J. [Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA) (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

2007-10-26T23:59:59.000Z

104

Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors  

SciTech Connect (OSTI)

This report describes the adaptation of a wind turbine performance code for use in the development of a general use design code and optimization method for stall-regulated horizontal-axis hydrokinetic turbine rotors. This rotor optimization code couples a modern genetic algorithm and blade-element momentum performance code in a user-friendly graphical user interface (GUI) that allows for rapid and intuitive design of optimal stall-regulated rotors. This optimization method calculates the optimal chord, twist, and hydrofoil distributions which maximize the hydrodynamic efficiency and ensure that the rotor produces an ideal power curve and avoids cavitation. Optimizing a rotor for maximum efficiency does not necessarily create a turbine with the lowest cost of energy, but maximizing the efficiency is an excellent criterion to use as a first pass in the design process. To test the capabilities of this optimization method, two conceptual rotors were designed which successfully met the design objectives.

Sale, D.; Jonkman, J.; Musial, W.

2009-08-01T23:59:59.000Z

105

E-Print Network 3.0 - advanced radiographic capability Sample...  

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

Science 3 Exhaustive matching of dental x-rays 1 Journal of the Canadian Society of Forensic Science, 41(3), 2008 Summary: ) radiograph with a marked region of interest (ROI), we...

106

Structural Design of a Horizontal-Axis Tidal Current Turbine Composite Blade  

SciTech Connect (OSTI)

This paper describes the structural design of a tidal composite blade. The structural design is preceded by two steps: hydrodynamic design and determination of extreme loads. The hydrodynamic design provides the chord and twist distributions along the blade length that result in optimal performance of the tidal turbine over its lifetime. The extreme loads, i.e. the extreme flap and edgewise loads that the blade would likely encounter over its lifetime, are associated with extreme tidal flow conditions and are obtained using a computational fluid dynamics (CFD) software. Given the blade external shape and the extreme loads, we use a laminate-theory-based structural design to determine the optimal layout of composite laminas such that the ultimate-strength and buckling-resistance criteria are satisfied at all points in the blade. The structural design approach allows for arbitrary specification of the chord, twist, and airfoil geometry along the blade and an arbitrary number of shear webs. In addition, certain fabrication criteria are imposed, for example, each composite laminate must be an integral multiple of its constituent ply thickness. In the present effort, the structural design uses only static extreme loads; dynamic-loads-based fatigue design will be addressed in the future. Following the blade design, we compute the distributed structural properties, i.e. flap stiffness, edgewise stiffness, torsion stiffness, mass, moments of inertia, elastic-axis offset, and center-of-mass offset along the blade. Such properties are required by hydro-elastic codes to model the tidal current turbine and to perform modal, stability, loads, and response analyses.

Bir, G. S.; Lawson, M. J.; Li, Y.

2011-10-01T23:59:59.000Z

107

3-Axis Magnetic Sensor Hybrid The Honeywell HMC2003 is a high sensitivity, three-axis magnetic sensor hybrid  

E-Print Network [OSTI]

3-Axis Magnetic Sensor Hybrid HMC2003 The Honeywell HMC2003 is a high sensitivity, three-axis magnetic sensor hybrid assembly used to measure low magnetic field strengths. Honeywell's most sensitive product excellence and performance by introducing innovative solid-state magnetic sensor solutions

Kleinfeld, David

108

13.024 Numerical Marine Hydrodynamics, Spring 2003  

E-Print Network [OSTI]

Introduction to numerical methods: interpolation, differentiation, integration, systems of linear equations. Solution of differential equations by numerical integration, partial differential equations of inviscid hydrodynamics: ...

Milgram, Jerome H.

109

Hydrodynamic experiment provides key data for Stockpile Stewardship  

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

predictively model and assess weapon performance in the absence of full-scale underground nuclear testing," said Webster. Los Alamos hydrodynamic experiment provides key data for...

110

Fast Lattice Boltzmann Solver for Relativistic Hydrodynamics  

SciTech Connect (OSTI)

A lattice Boltzmann formulation for relativistic fluids is presented and numerically validated through quantitative comparison with recent hydrodynamic simulations of relativistic fluids. In order to illustrate its capability to handle complex geometries, the scheme is also applied to the case of a three-dimensional relativistic shock wave, generated by a supernova explosion, impacting on a massive interstellar cloud. This formulation opens up the possibility of exporting the proven advantages of lattice Boltzmann methods, namely, computational efficiency and easy handling of complex geometries, to the context of (mildly) relativistic fluid dynamics at large, from quark-gluon plasmas up to supernovae with relativistic outflows.

Mendoza, M.; Herrmann, H. J. [ETH Zuerich, Computational Physics for Engineering Materials, Institute for Building Materials, Schafmattstrasse 6, HIF, CH-8093 Zuerich (Switzerland); Boghosian, B. M. [Department of Mathematics, Tufts University, Bromfield-Pearson, Medford, Massachusetts 02155 (United States); Succi, S. [Istituto per le Applicazioni del Calcolo C.N.R., Via dei Taurini, 19 00185, Rome (Italy) and Freiburg Institute for Advanced Studies, Albertstrasse, 19, D-79104, Freiburg (Germany)

2010-07-02T23:59:59.000Z

111

Hydrodynamic and Spectral Simulations of HMXB Winds  

E-Print Network [OSTI]

We describe preliminary results of a global model of the radiatively-driven photoionized wind and accretion flow of the high-mass X-ray binary Vela X-1. The full model combines FLASH hydrodynamic calculations, XSTAR photoionization calculations, HULLAC atomic data, and Monte Carlo radiation transport. We present maps of the density, temperature, velocity, and ionization parameter from a FLASH two-dimensional time-dependent simulation of Vela X-1, as well as maps of the emissivity distributions of the X-ray emission lines.

Christopher W. Mauche; Duane A. Liedahl; Shizuka Akiyama; Tomasz Plewa

2007-04-02T23:59:59.000Z

112

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

113

MHK Technologies/Vertical Axis Venturi System | Open Energy Information  

Open Energy Info (EERE)

Axis Venturi System Axis Venturi System < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage 275px Technology Profile Primary Organization Warrior Girl Corporation Technology Resource Click here Current Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description The proprietary venturi system uses two venturies one on the upstream side of the vertical axis turbine to force the water flow into the turbine and one at the downstream side of the turbine which creates a lower pressure region that pulls the water through the turbine The vertical axis orientation of the turbine is believed by the company to allow for efficiency gains

114

Curvature gouge detection and prevention in 5-axis CNC machining.  

E-Print Network [OSTI]

??Five-axis CNC machining presents high efficiency and unparallel flexibility in the machining of complex curved surfaces. However, generation of gouge-free CNC tool path and cutter… (more)

Wang, Yin Jack

2010-01-01T23:59:59.000Z

115

A hybrid type small 5-axis CNC milling machine  

E-Print Network [OSTI]

5-axis CNC milling machines are important in a number of industries ranging from aerospace to consumer-die-mold machining because they can deliver high machining accuracy with a spindle tilting capacity. Most of these ...

Son, Seung-Kil, 1964-

2002-01-01T23:59:59.000Z

116

Center of pressure calculations for a bent-axis vehicle  

SciTech Connect (OSTI)

Bent-axis maneuvering vehicles provide a unique type of control for a variety of supersonic and hypersonic missions. Unfortunately, large hinge moments, incomplete pitching moment predictions, and a misunderstanding of corresponding center of pressure calculations have prevented their application. A procedure is presented for the efficient design of bent-axis vehicles given an adequate understanding of origins of pitching moment effects. In particular,sources of pitching moment contributions will be described including not only normal force, but inviscid axial force and viscous effects as well. Off-centerline center of pressure effects are first reviewed for symmetric hypersonic sphere-cone configurations. Next the effects of the bent-axis geometry are considered where axial force, acting on the deflected tail section, can generate significant pitching moment components. The unique relationship between hinge moments and pitching moments for the bent-axis class of vehicles is discussed. 15 refs.

Rutledge, W.H.; Polansky, G.F.

1992-01-01T23:59:59.000Z

117

Relativistic hydrodynamics with quantum hadrodynamics equation of state  

Science Journals Connector (OSTI)

We derive the equation of state of the quantum hydrodynamics Lagrangian in a classical approach. The obtained equation of state is then used as input in a relativistic hydrodynamical numerical routine. Rapidity and transverse momentum distributions are calculated and compared with experimental data on heavy ion collisions obtained at the Brookhaven National Laboratory Alternating Gradient Synchrotron and the CERN Super Proton Synchrotron.

D. P. Menezes; F. S. Navarra; M. Nielsen; U. Ornik

1993-06-01T23:59:59.000Z

118

Suspended sediment and hydrodynamics above mildly sloped long wave ripples  

E-Print Network [OSTI]

Suspended sediment and hydrodynamics above mildly sloped long wave ripples Yeon S. Chang of suspended sediment and the associated hydrodynamics over mildly sloped long wave ripples on the inner shelf m. The vertical and temporal structures of the suspended sediment concentration (SSC) are consistent

Kirby, James T.

119

Hydrodynamics of three-dimensional stacked hexatic liquid crystals  

Science Journals Connector (OSTI)

The hydrodynamic equations for three-dimensional stacked hexatic liquid crystals, i.e., for hexatic-B and its tilted analogs, smectic-F and smectic-I, are presented. Differences and similarities to the hydrodynamics of smectic-A and smectic-C are discussed and the role of the additional variable characterizing the bond orientational order is elucidated.

H. Pleiner and H. R. Brand

1984-02-01T23:59:59.000Z

120

Green's functions and hydrodynamics for isotopic binary diffusion  

E-Print Network [OSTI]

We study classical binary fluid mixtures in which densities vary on very short time (ps) and length (nm) scales, such that hydrodynamics does not apply. In a pure fluid with a localized heat pulse the breakdown of hydrodynamics was overcome using Green's functions which connect the initial densities to those at later times. Numerically it appeared that for long times the results from the Green's functions would approach hydrodynamics. In this paper we extend the Green's functions theory to binary mixtures. For the case of isothermal isobaric mutual diffusion in isotopic binary mixtures and ideal binary mixtures, which is easier to handle than heat conduction yet still non-trivial, we show analytically that in the Green's function approach one recovers hydrodynamic behaviour at long time scales provided the system reaches local equilibrium at long times. This is a first step toward giving the Green's function theory a firmer basis because it can for this case be considered as an extension of hydrodynamics.

R. van Zon; E. G. D. Cohen

2005-08-10T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Hydrodynamical random walker with chemotactic memory  

E-Print Network [OSTI]

A three-dimensional hydrodynamical model for a micro random walker is combined with the idea of chemotactic signaling network of E. coli. Diffusion exponents, orientational correlation functions and their dependence on the geometrical and dynamical parameters of the system are analyzed numerically. Because of the chemotactic memory, the walker shows superdiffusing displacements in all directions with the largest diffusion exponent for a direction along the food gradient. Mean square displacements and orientational correlation functions show that the chemotactic memory washes out all the signatures due to the geometrical asymmetry of the walker and statistical properties are asymmetric only with respect to the direction of food gradient. For different values of the memory time, the Chemotactic index (CI) is also calculated.

H. Mohammady; B. Esckandariun; A. Najafi

2014-10-01T23:59:59.000Z

122

On some hydrodynamical aspects of quantum mechanics  

E-Print Network [OSTI]

In this note we first set up an analogy between spin and vorticity of a perfect 2d-fluid flow, based on the Borel-Weil contruction of the irreducible unitary representations of SU(2), and looking at the Madelung-Bohm velocity attached to the ensuing spin wave functions. We also show that, in the framework of finite dimensional geometric quantum mechanics, the Schr\\"odinger velocity field on projective Hilbert space is divergence-free (being Killing with respect to the Fubini-Study metric) and fulfils the stationary Euler equation, with pressure proportional to the Hamiltonian uncertainty (squared). We explicitly compute the pressure gradient of this "Schr\\"odinger fluid" and determine its critical points. Its vorticity is also calculated and shown to depend on the spacings of the energy levels. These results follow from hydrodynamical properties of Killing vector fields valid in any (finite dimensional) Riemannian manifold, of possible independent interest.

Mauro Spera

2009-02-04T23:59:59.000Z

123

An Owner's Guide to Smoothed Particle Hydrodynamics  

E-Print Network [OSTI]

We present a practical guide to Smoothed Particle Hydrodynamics (\\SPH) and its application to astrophysical problems. Although remarkably robust, \\SPH\\ must be used with care if the results are to be meaningful since the accuracy of \\SPH\\ is sensitive to the arrangement of the particles and the form of the smoothing kernel. In particular, the initial conditions for any \\SPH\\ simulation must consist of particles in dynamic equilibrium. We describe some of the numerical difficulties that may be encountered when using \\SPH, and how these may be overcome. Through our experience in using \\SPH\\ code to model convective stars, galaxy clusters and large scale structure problems we have developed many diagnostic tests. We give these here as an aid to rapid identification of errors, together with a list of basic prerequisites for the most efficient implementation of \\SPH.

T. J. Martin; F. R. Pearce; P. A. Thomas

1993-10-13T23:59:59.000Z

124

Hydrodynamical random walker with chemotactic memory  

E-Print Network [OSTI]

A three-dimensional hydrodynamical model for a micro random walker is combined with the idea of chemotactic signaling network of E. coli. Diffusion exponents, orientational correlation functions and their dependence on the geometrical and dynamical parameters of the system are analyzed numerically. Because of the chemotactic memory, the walker shows superdiffusing displacements in all directions with the largest diffusion exponent for a direction along the food gradient. Mean square displacements and orientational correlation functions show that the chemotactic memory washes out all the signatures due to the geometrical asymmetry of the walker and statistical properties are asymmetric only with respect to the direction of food gradient. For different values of the memory time, the Chemotactic index (CI) is also calculated.

Mohammady, H; Najafi, A

2014-01-01T23:59:59.000Z

125

Impacts of Raindrop Fall Velocity and Axis Ratio Errors on Dual-Polarization Radar Rainfall Estimation  

Science Journals Connector (OSTI)

Motivated by the field observations of fall velocity and axis ratio deviations from predicted terminal velocity and equilibrium axis ratio values, the combined effects of raindrop fall velocity and axis ratio deviations on dual-polarization radar ...

Bin Pei; Firat Y. Testik; Mekonnen Gebremichael

2014-10-01T23:59:59.000Z

126

Three fluid hydrodynamics of spin-1 Bose-Einstein condensates  

E-Print Network [OSTI]

We study excitations of the spin-1 Bose gas at finite temperatures and in the presence of a not so strong magnetic field, or equivalently, when the gas sample is partially polarized. Motivated by the success of two-fluid hydrodynamics of scalar superfluids we develop a three-fluid hydrodynamic description to treat the low frequency and long wavelength excitations of the spin-1 Bose gas. We derive the coupled linear hydrodynamic equations of the three sounds and evaluate them numerically in a self-consistent mean field approximation valid for the dilute gas at the intermediate and critical temperature regions. In this latter region we identify the critical mode.

Gergely Szirmai; Peter Szepfalusy

2011-12-14T23:59:59.000Z

127

Three fluid hydrodynamics of spin-1 Bose-Einstein condensates  

E-Print Network [OSTI]

We study excitations of the spin-1 Bose gas at finite temperatures and in the presence of a not so strong magnetic field, or equivalently, when the gas sample is partially polarized. Motivated by the success of two-fluid hydrodynamics of scalar superfluids we develop a three-fluid hydrodynamic description to treat the low frequency and long wavelength excitations of the spin-1 Bose gas. We derive the coupled linear hydrodynamic equations of the three sounds and evaluate them numerically in a self-consistent mean field approximation valid for the dilute gas at the intermediate and critical temperature regions. In this latter region we identify the critical mode.

Szirmai, Gergely

2011-01-01T23:59:59.000Z

128

Z-Axis Tipper Electromagnetics | Open Energy Information  

Open Energy Info (EERE)

Z-Axis Tipper Electromagnetics Z-Axis Tipper Electromagnetics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Z-Axis Tipper Electromagnetics Details Activities (2) Areas (2) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Magnetotelluric Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Cost Information Low-End Estimate (USD): 4,827.00482,700 centUSD 4.827 kUSD 0.00483 MUSD 4.827e-6 TUSD / mile Median Estimate (USD): 6,206.14620,614 centUSD 6.206 kUSD 0.00621 MUSD 6.20614e-6 TUSD / mile High-End Estimate (USD): 17,239.291,723,929 centUSD 17.239 kUSD 0.0172 MUSD 1.723929e-5 TUSD / mile Dictionary.png

129

T-613: Microsoft Excel Axis Properties Remote Code Execution Vulnerability  

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

613: Microsoft Excel Axis Properties Remote Code Execution 613: Microsoft Excel Axis Properties Remote Code Execution Vulnerability T-613: Microsoft Excel Axis Properties Remote Code Execution Vulnerability May 2, 2011 - 7:42am Addthis PROBLEM: Microsoft Excel is prone to a remote code-execution vulnerability because the applications fail to sufficiently validate user-supplied input. PLATFORM: Microsoft Excel (2002-2010) ABSTRACT: Microsoft Excel is prone to a remote code-execution vulnerability because the applications fails to sufficiently validate user-supplied input. Attackers can exploit this issue by enticing an unsuspecting user to open a specially crafted Excel file. Successful exploits can allow attackers to execute arbitrary code with the privileges of the user running the application. Failed exploit attempts will result in a denial-of-service

130

MHK Technologies/Horizontal Axis Logarithmic Spiral Turbine | Open Energy  

Open Energy Info (EERE)

Horizontal Axis Logarithmic Spiral Turbine Horizontal Axis Logarithmic Spiral Turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Technology Profile Primary Organization Golden Turbines LLC Technology Resource Click here Current Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description A Horizontal axis Water turbine following the logarithmic spiral to generate clean electric energy from slow moving currents like rivers or ocean currents and with least impact on marine life and the environment because it doesn t require a damn or building huge structures Technology Dimensions Device Testing Date Submitted 36:09.5 << Return to the MHK database homepage

131

Four-axis micro measuring systems performance verification  

Science Journals Connector (OSTI)

Abstract This article describes the performance verification of 3D optical measuring instruments integrating a rotational axis using an artifact. The goal is the performance verification of four-axis measuring systems for the full 3D acquisition of micro-geometric parts. This type of measurement has many potential applications, such as in micro-tool, micro-mold, or micro-device manufacturing. The artifact is as simple as possible to reduce manufacturing costs, ensure easy calibration, comply with the ISO 10360 standard and consider all volumetric error contributions. The artifact may be useful to both measuring system manufacturers and users to provide a measurement traceability path.

Giovanni Moroni; Stefano Petrò; Wahyudin P. Syam

2014-01-01T23:59:59.000Z

132

Property:Hydrodynamic Testing Facility Type | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamic Testing Facility Type Hydrodynamic Testing Facility Type Jump to: navigation, search Property Name Hydrodynamic Testing Facility Type Property Type Page Pages using the property "Hydrodynamic Testing Facility Type" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + Flume + 10-ft Wave Flume Facility + Flume + 11-ft Wave Flume Facility + Flume + 2 2-ft Flume Facility + Flume + 3 3-ft Wave Flume Facility + Flume + 5 5-ft Wave Flume Facility + Flume + 6 6-ft Wave Flume Facility + Flume + A Alden Large Flume + Flume + Alden Small Flume + Flume + Alden Tow Tank + Tow Tank + Alden Wave Basin + Wave Basin + B Breakwater Research Facility + Wave Basin + Bucknell Hydraulic Flume + Flume + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + Tunnel +

133

Bulk viscosity and cavitation in boost-invariant hydrodynamic expansion  

E-Print Network [OSTI]

We solve second order relativistic hydrodynamics equations for a boost-invariant 1+1-dimensional expanding fluid with an equation of state taken from lattice calculations of the thermodynamics of strongly coupled quark-gluon ...

Rajagopal, Krishna

134

Foundation of Hydrodynamics for Systems with Strong Interactions  

E-Print Network [OSTI]

For a dense and strongly interacting system, such as a nucleus or a strongly-coupled quark-gluon plasma, the foundation of hydrodynamics can be better found in the quantum description of constituents moving in the strong mean fields generated by all other particles. Using the result that the Schroedinger equation and the Klein-Gordon equation can be written in hydrodynamical forms, we find that the probability currents of the many-body system in the mean-field description obey a hydrodynamical equation with stress tensors arising from many contributions: quantum effects, mean-field interactions, and thermal fluctuations. The influence of various contributions to the hydrodynamical motion is expected to vary with the temperature, as the quantum and mean-field stress tensors playing more important roles at low and moderate temperatures.

Cheuk-Yin Wong

2010-11-30T23:59:59.000Z

135

Simulation of Wave Effect on Ship Hydrodynamics by RANSE  

Science Journals Connector (OSTI)

The application of advanced numerical methods based on the solution of RANSE and VOF equations on the prediction of ship hydrodynamics is presented. The test cases selected ... restrained and free oblique motions...

Qiuxin Gao; Dracos Vassalos

2011-01-01T23:59:59.000Z

136

Hydrodynamic analysis of mooring lines based on optical tracking experiments  

E-Print Network [OSTI]

of mooring lines on the global motions of a moored offshore platform. In the present study, an experimental investigation of the hydrodynamic characteristics of various mooring elements is implemented through free and forced oscillation tests. Since no direct...

Yang, Woo Seuk

2009-05-15T23:59:59.000Z

137

13.012 Hydrodynamics for Ocean Engineering, Fall 2002  

E-Print Network [OSTI]

Development of the fundamental equations of fluid mechanics and their simplifications for several areas of marine hydrodynamics. Application of these principles to the solution of ocean engineering problems. Topics include ...

Techet, Alexandra Hughes

138

Second-Order Accurate Method for Solving Radiation-Hydrodynamics  

E-Print Network [OSTI]

Second-order discretization for radiation-hydrodynamics is currently an area of great interest. Second-order methods used to solve the respective single-physics problems often differ fundamentally, making it difficult to combine them in a second...

Edwards, Jarrod Douglas

2013-11-12T23:59:59.000Z

139

Follow-up on the Los Alamos National Laboratory Hydrodynamic...  

Office of Environmental Management (EM)

Follow-up on the Los Alamos National Laboratory Hydrodynamic Test Program DOEIG-0930 December 2014 U.S. Department of Energy Office of Inspector General Office of Audits and...

140

Commutators in Quantum Hydrodynamics for Interacting Bose Systems  

Science Journals Connector (OSTI)

It is shown that the curl of the velocity operator in the second quantized version of quantum hydrodynamics for interacting Bose systems is equal to zero, thus resolving the apparent discrepancies between various existing formulations.

Robert Fanelli and R. E. Struzynski

1969-06-05T23:59:59.000Z

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


141

Hydrodynamics of He3 in Anisotropic A Phase  

Science Journals Connector (OSTI)

The hydrodynamic theory of mass transport in A-He3 is derived from that phase's broken symmetries and thermodynamics. First, second, and fourth sound as well as orbit waves are obtained as the normal modes.

Robert Graham

1974-12-09T23:59:59.000Z

142

An implicit Smooth Particle Hydrodynamic code  

SciTech Connect (OSTI)

An implicit version of the Smooth Particle Hydrodynamic (SPH) code SPHINX has been written and is working. In conjunction with the SPHINX code the new implicit code models fluids and solids under a wide range of conditions. SPH codes are Lagrangian, meshless and use particles to model the fluids and solids. The implicit code makes use of the Krylov iterative techniques for solving large linear-systems and a Newton-Raphson method for non-linear corrections. It uses numerical derivatives to construct the Jacobian matrix. It uses sparse techniques to save on memory storage and to reduce the amount of computation. It is believed that this is the first implicit SPH code to use Newton-Krylov techniques, and is also the first implicit SPH code to model solids. A description of SPH and the techniques used in the implicit code are presented. Then, the results of a number of tests cases are discussed, which include a shock tube problem, a Rayleigh-Taylor problem, a breaking dam problem, and a single jet of gas problem. The results are shown to be in very good agreement with analytic solutions, experimental results, and the explicit SPHINX code. In the case of the single jet of gas case it has been demonstrated that the implicit code can do a problem in much shorter time than the explicit code. The problem was, however, very unphysical, but it does demonstrate the potential of the implicit code. It is a first step toward a useful implicit SPH code.

Charles E. Knapp

2000-04-01T23:59:59.000Z

143

RADIOGRAPHIC IMAGING BELOW A VOLCANIC CRATER FLOOR WITH COSMIC-RAY MUONS  

E-Print Network [OSTI]

horizontally-arriving cosmic ray muon with energy of 1 TeV can penetrate 2.6 km of water. Thus, cosmic-ray muon that uncertainty on the shape and amplitude of the energy spectrum of the muon source is within a few percentRADIOGRAPHIC IMAGING BELOW A VOLCANIC CRATER FLOOR WITH COSMIC-RAY MUONS HIROYUKI K.M. TANAKA

Aoki, Yosuke

144

A Simplified Morphing Blade for Horizontal Axis Wind Turbines  

E-Print Network [OSTI]

A Simplified Morphing Blade for Horizontal Axis Wind Turbines Weijun WANG , St´ephane CARO, Fouad salinas@hotmail.com The aim of designing wind turbine blades is to improve the power capture ability by adjusting the twist of the blade's root and tip. To evaluate the performance of wind turbine blades

Recanati, Catherine

145

E-Print Network 3.0 - axis wind turbines Sample Search Results  

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

turbines Search Powered by Explorit Topic List Advanced Search Sample search results for: axis wind turbines...

146

E-Print Network 3.0 - axis wind turbine Sample Search Results  

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

turbine Search Powered by Explorit Topic List Advanced Search Sample search results for: axis wind turbine...

147

Audit Report: IG-0599 | Department of Energy  

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

9 9 Audit Report: IG-0599 May 22, 2003 Dual Axis Radiographic Hydrodynamic Test Facility The Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is an experimental facility of the Stockpile Stewardship Program. The facility will provide high-speed, high-resolution flash radiographs to diagnose the results of hydrodynamic tests and dynamic experiments. Construction of DARHT began in 1988. Since that time, the project has undergone several baseline changes impacting different technical aspects of the project. Original plans called for the development of two single-pulse axes with similar capabilities at a cost of $30 million. In 1998, the scope was changed to expand the capability of the second axis while at the same time increasing the cost to $270 million. The following photograph shows DARHT's

148

EIS-0228: Record of Decision | Department of Energy  

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

28: Record of Decision 28: Record of Decision EIS-0228: Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility The Department of Energy (DOE) is issuing this Record of Decision (ROD) regarding the DOE's proposed Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL) in northern New Mexico. DOE has decided to complete and operate the DARHT facility at LANL while implementing a program to conduct most tests inside steel containment vessels, with containment to be phased in over ten years. DOE/EIS-0228, Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility, 60 FR 53588 (October 1995) More Documents & Publications EIS-0183: Record of Decision EIS-0380: Mitigation Action Plan Annual Report Audit Report: IG-0599

149

EIS-0228: Record of Decision | Department of Energy  

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

8: Record of Decision 8: Record of Decision EIS-0228: Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility The Department of Energy (DOE) is issuing this Record of Decision (ROD) regarding the DOE's proposed Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL) in northern New Mexico. DOE has decided to complete and operate the DARHT facility at LANL while implementing a program to conduct most tests inside steel containment vessels, with containment to be phased in over ten years. DOE/EIS-0228, Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility, 60 FR 53588 (October 1995) More Documents & Publications EIS-0183: Record of Decision EIS-0380: Mitigation Action Plan Annual Report Audit Report: IG-0699

150

Further development of a versatile computer-assisted learning program for dental education with an exemplifying application on how to logically arrange and mount periapical and bitewing radiographs  

Science Journals Connector (OSTI)

To develop interactive computer-assisted learning software for teaching dental students to logically arrange periapical and bitewing radiographs.

Hideyuki Tanimoto; Hans-Göran Gröndahl; Kerstin Gröndahl; Yoshinori Arai

2006-12-01T23:59:59.000Z

151

Serotonin, tryptophan metabolism and the brain-gut-microbiome axis  

Science Journals Connector (OSTI)

Abstract The brain-gut axis is a bidirectional communication system between the central nervous system and the gastrointestinal tract. Serotonin functions as a key neurotransmitter at both terminals of this network. Accumulating evidence points to a critical role for the gut microbiome in regulating normal functioning of this axis. In particular, it is becoming clear that the microbial influence on tryptophan metabolism and the serotonergic system may be an important node in such regulation. There is also substantial overlap between behaviours influenced by the gut microbiota and those which rely on intact serotonergic neurotransmission. The developing serotonergic system may be vulnerable to differential microbial colonisation patterns prior to the emergence of a stable adult-like gut microbiota. At the other extreme of life, the decreased diversity and stability of the gut microbiota may dictate serotonin-related health problems in the elderly. The mechanisms underpinning this crosstalk require further elaboration but may be related to the ability of the gut microbiota to control host tryptophan metabolism along the kynurenine pathway, thereby simultaneously reducing the fraction available for serotonin synthesis and increasing the production of neuroactive metabolites. The enzymes of this pathway are immune and stress-responsive, both systems which buttress the brain-gut axis. In addition, there are neural processes in the gastrointestinal tract which can be influenced by local alterations in serotonin concentrations with subsequent relay of signals along the scaffolding of the brain-gut axis to influence CNS neurotransmission. Therapeutic targeting of the gut microbiota might be a viable treatment strategy for serotonin-related brain-gut axis disorders.

S.M. O’Mahony; G. Clarke; Y.E. Borre; T.G. Dinan; J.F. Cryan

2015-01-01T23:59:59.000Z

152

Lattice-Boltzmann modeling of phonon hydrodynamics  

Science Journals Connector (OSTI)

Based on the phonon Boltzmann equation, a lattice-Boltzmann model for phonon hydrodynamics is developed. Both transverse and longitudinal polarized phonons that interact through normal and umklapp processes are considered in the model. The collision term is approximated by the relaxation time model where normal and umklapp processes tend to relax distributions of phonons to their corresponding equilibrium distribution functions—the displaced Planck distribution and the Planck distribution, respectively. A macroscopic phonon thermal wave equation (PTWE), valid for the second-sound mode, is derived through the technique of Chapman-Enskog expansion. Compared to the dual-phase-lag (DPL) -based thermal wave equation, the PTWE has an additional fourth-ordered spatial derivative term. The fundamental difference between the two models is discussed through examining a propagating thermal pulse in a single-phased medium and the transient and steady-state transport phenomena on a two-layered structure subjected to different temperatures at boundaries. Results show that transport phenomena are significantly different between the two models. The behavior exhibited by the DPL model, as thermal wave behavior goes over to diffusive behavior, ?T??q is incompatible with any microscopic phonon propagating mode. Unlike the DPL model, in which ?T only has an effect on the transient phenomena, in the PTWE model ?T shows effects on phenomena at both transient and steady state. With the intrinsic compatibility to the microscopic state, discontinuous quantities, such as a jump of temperature at a boundary or at an interface, can be calculated naturally and straightforwardly with the present lattice-Boltzmann method.

Wen-Shu Jiaung and Jeng-Rong Ho

2008-06-23T23:59:59.000Z

153

Hydrodynamic construction of the electromagnetic field  

E-Print Network [OSTI]

We present an alternative Eulerian hydrodynamic model for the electromagnetic field in which the discrete vector indices in Maxwell\\s equations are replaced by continuous angular freedoms, and develop the corresponding Lagrangian picture in which the fluid particles have rotational and translational freedoms. This enables us to extend to the electromagnetic field the exact method of state construction proposed previously for spin 0 systems, in which the time-dependent wavefunction is computed from a single-valued continuum of deterministic trajectories where two spacetime points are linked by at most a single orbit. The deduction of Maxwell\\s equations from continuum mechanics is achieved by generalizing the spin 0 theory to a general Riemannian manifold from which the electromagnetic construction is extracted as a special case. In particular, the flat-space Maxwell equations are represented as a curved-space Schr\\"odinger equation for a massive system. The Lorentz covariance of the Eulerian field theory is obtained from the non-covariant Lagrangian-coordinate model as a kind of collective effect. The method makes manifest the electromagnetic analogue of the quantum potential that is tacit in Maxwell\\s equations. This implies a novel definition of the \\classical limit\\ of Maxwell\\s equations that differs from geometrical optics. It is shown that Maxwell\\s equations may be obtained by canonical quantization of the classical model. Using the classical trajectories a novel expression is derived for the propagator of the electromagnetic field in the Eulerian picture. The trajectory and propagator methods of solution are illustrated for the case of a light wave.

Peter Holland

2014-10-03T23:59:59.000Z

154

Vertical-axis wind turbines -- The current status of an old technology  

SciTech Connect (OSTI)

Vertical-axis wind turbine technology is not well understood, even though the earliest wind machines rotated about a vertical axis. The operating environment of a vertical-axis wind turbine is quite complex, but detailed analysis capabilities have been developed and verified over the last 30 years. Although vertical-axis technology has not been widely commercialized, it exhibits both advantages and disadvantages compared to horizontal-axis technology, and in some applications, it appears to offer significant advantages.

Berg, D.E.

1996-12-31T23:59:59.000Z

155

Hydrodynamic Efficiency of Ablation Propulsion with Pulsed Ion Beam  

SciTech Connect (OSTI)

This paper presents the hydrodynamic efficiency of ablation plasma produced by pulsed ion beam on the basis of the ion beam-target interaction. We used a one-dimensional hydrodynamic fluid compressible to study the physics involved namely an ablation acceleration behavior and analyzed it as a rocketlike model in order to investigate its hydrodynamic variables for propulsion applications. These variables were estimated by the concept of ablation driven implosion in terms of ablated mass fraction, implosion efficiency, and hydrodynamic energy conversion. Herein, the energy conversion efficiency of 17.5% was achieved. In addition, the results show maximum energy efficiency of the ablation process (ablation efficiency) of 67% meaning the efficiency with which pulsed ion beam energy-ablation plasma conversion. The effects of ion beam energy deposition depth to hydrodynamic efficiency were briefly discussed. Further, an evaluation of propulsive force with high specific impulse of 4000s, total impulse of 34mN and momentum to energy ratio in the range of {mu}N/W was also analyzed.

Buttapeng, Chainarong; Yazawa, Masaru; Harada, Nobuhiro [Department of Electrical Engineering, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka 940-2188 (Japan); Suematsu, Hisayuki; Jiang Weihua; Yatsui, Kiyoshi [Extreme Energy-Density Research Institute, Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka 940-2188 (Japan)

2006-05-02T23:59:59.000Z

156

Nonlinear reversible hydrodynamics of the superfluid phases of He3  

Science Journals Connector (OSTI)

The nonlinear reversible hydrodynamic equations for the superfluid phases of He3, i.e., He3-A, He3-A1, He3-B, He3-A in high magnetic fields, and He3-B in high magnetic fields, are derived. The Mermin-Ho—type relations for He3-A in high magnetic fields and He3-B in high magnetic fields are given for the first time. The influence of higher-order gradient terms in all phases is discussed, and a new class of nonlinear terms containing the various kinds of velocities is given which have not been considered so far for any of the five superfluid phases. In addition we show that the hydrodynamic equations for He3-A in high magnetic fields contain as a special case the hydrodynamics of superfluid He3-A1 and the orbit part of the hydrodynamic equations for He3 without external field. Furthermore, we point out some structural similarities in the equations for He3-A in high magnetic fields and He3-B in high magnetic fields. As an additional effect we find that the higher-order gradient terms imply a preferred direction in the hydrodynamic equations for superfluid He3-B.

H. Pleiner and H. Brand

1981-12-01T23:59:59.000Z

157

Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie Valley  

Open Energy Info (EERE)

Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie Valley Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie Valley Geothermal Area- A Reactive Transport Modeling Approach Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie Valley Geothermal Area- A Reactive Transport Modeling Approach Abstract A 2D reactive transport model of the Dixie Valley,Nevada, geothermal area was developed to assessfluid flow pathways and fluid rock interactionprocesses. Setting up the model includedspecification of the mineralogy of the different rockunits, the formulation of the corresponding mineraldissolution and precipitation reactions, the explicitdefinition of two major normal faults and thespecification of a dual continuum domain

158

University of New Hampshire Hydrodynamics | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamics Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of New Hampshire Address Chase Ocean Engineering Laboratory, 24 Colovos Road Place Durham, NH Zip 03824 Sector Hydro Phone number (603) 862-0672 Website http://marine.unh.edu/faciliti Coordinates 43.1362084°, -70.9387742° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.1362084,"lon":-70.9387742,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

159

Liquid friction on charged surfaces: from hydrodynamic slippage to electrokinetics  

E-Print Network [OSTI]

Hydrodynamic behavior at the vicinity of a confining wall is closely related to the friction properties of the liquid/solid interface. Here we consider, using Molecular Dynamics simulations, the electric contribution to friction for charged surfaces, and the induced modification of the hydrodynamic boundary condition at the confining boundary. The consequences of liquid slippage for electrokinetic phenomena, through the coupling between hydrodynamics and electrostatics within the electric double layer, are explored. Strong amplification of electro-osmotic effects is revealed, and the non-trivial effect of surface charge is discussed. This work allows to reconsider existing experimental data, concerning Zeta potentials of hydrophobic surfaces and suggest the possibility to generate ``giant'' electro-osmotic and electrophoretic effects, with direct applications in microfluidics.

Laurent Joly; Christophe Ybert; Emmanuel Trizac; Lyderic Bocquet

2006-07-19T23:59:59.000Z

160

Discharge convective instability as modifier of nonlinear hydrodynamic spectrum  

E-Print Network [OSTI]

Discharge source is considered as modifier of flow hydrodynamic spectrum. Characteristic frequency of nonlinear spectrum and spectrum power were determined under conditions of arc sliding discharge in supersonic flow. Two stages of discharge were defined: sliding stage and still stage. It was found that stage transition occurs due to convective instability of discharge. Fraction of sliding stage in overall discharge duration is determined by averaged current that is general stable discharge parameter. This phenomenon gives opportunity to control power of pressure fluctuations spectrum. Theoretical insight of field and hydrodynamic factors influencing on pulsations frequency was achieved. Hydrodynamic resistance of discharge region and holding cathode electric field turned out to be basic factors of frequency modification. Corresponding experimental verification was taken. Basic frequency law was determined for several discharge regimes.

Sergey Kamenshchikov

2012-04-26T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Time-domain simulation of the full hydrodynamic model  

E-Print Network [OSTI]

A simple upwind discretization of the highly coupled non-linear differential equations which define the hydrodynamic model for semiconductors is given in full detail. The hydrodynamic model is able to describe inertia effects which play an increasing role in different fields of opto- and microelectronics. A silicon $n^+ - n - n^+$ - structure is simulated, using the energy-balance model and the full hydrodynamic model. Results for stationary cases are then compared, and it is pointed out where the energy-balance model, which is implemented in most of today's commercial semiconductor device simulators, fails to describe accurately the electron dynamics. Additionally, a GaAs $n^+ - n - n^+$-structure is simulated in time-domain in order to illustrate the importance of inertia effects at high frequencies in modern submicron devices.

Aste, A

2003-01-01T23:59:59.000Z

162

3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK  

SciTech Connect (OSTI)

3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.

Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D

2006-08-24T23:59:59.000Z

163

Application of a panel method to hydrodynamics of underwater vehicles  

SciTech Connect (OSTI)

A low-order singularity panel method based on Green`s formulation is used to predict the hydrodynamics characteristics of underwater vehicles. The low-order modeling employs constant strength sources and doublets, and the body surface is modeled by quadrilaterals. The method is first applied to predicting the force and moment coefficients of underwater vehicles for the body-alone and finned configurations. Hydrodynamic coefficients of added mass and added moment of inertia are also calculated by modifying the code. Results for several two and three-dimensional bodies show the usefulness of the method for predicting the added mass and added moment of inertia.

Sahin, I. [Western Michigan Univ., Kalamazoo, MI (United States); Crane, J.W.; Watson, K.P. [Naval Surface Warfare Center, Panama City, FL (United States)

1994-12-31T23:59:59.000Z

164

Design of a novel six-axis metrology system for meso-scale nanopositioners  

E-Print Network [OSTI]

The purpose of this research is to develop the best possible means and methods of building a six axis metrology system given cost and space constraints. Six axis measurements are a crucial part of precision engineering and ...

King, Ryan N. (Ryan Nicholas)

2009-01-01T23:59:59.000Z

165

E-Print Network 3.0 - atlas und axis Sample Search Results  

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

axis Search Powered by Explorit Topic List Advanced Search Sample search results for: atlas und axis Page: << < 1 2 3 4 5 > >> 1 Mitteilung fr die Medien Mitteilung fr die Medien...

166

Blockage effects on the hydrodynamic performance of a marine cross-flow turbine  

Science Journals Connector (OSTI)

...the hydrodynamic efficiency of the turbine for blockage ratios...0820.131. Turbine performance, kinetic and hydrodynamic efficiencies were only marginally...Crawford 2010 Overall efficiency of ducted tidal current turbines. In Proc. OCEANS...

2013-01-01T23:59:59.000Z

167

Lattice Boltzmann algorithm for three–dimensional liquid–crystal hydrodynamics  

Science Journals Connector (OSTI)

...P. Boon and P. V. Coveney Lattice Boltzmann algorithm for three-dimensional...hydrodynamics We describe a lattice Boltzmann algorithm to simulate liquid-crystal...nematics with an imposed twist. lattice Boltzmann|liquid crystal|hydrodynamics...

2004-01-01T23:59:59.000Z

168

An impulse framework for hydrodynamic force analysis : fish propulsion, water entry of spheres, and marine propellers  

E-Print Network [OSTI]

This thesis presents an impulse framework for analyzing the hydrodynamic forces on bodies in flow. This general theoretical framework is widely applicable, and it is used to address the hydrodynamics of fish propulsion, ...

Epps, Brenden P

2010-01-01T23:59:59.000Z

169

A Multi-Axis Seam Tracking sensor for joining applications  

SciTech Connect (OSTI)

This paper describes the development and use of the Multi-Axis Seam Tracking (MAST) sensor for tracking seams or other features in real-time. Four independent, spatially-distributed electric fields are used to sense changes in the relative position of the sensor and the workpiece. The MAST sensor is very inexpensive compared with commercially available seam tracking sensors. It can be used in systems to perform cost-effective small-lot manufacturing operations in a faster, more consistent manner. The MAST sensor is used in an automated system for dispensing braze paste during a rocket nozzle fabrication process.

Novak, J.L.; Schmitt, D.J. [Sandia National Labs., Albuquerque, NM (United States); Maslakowski, J. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

1993-11-01T23:59:59.000Z

170

Multi-Axis Seam Tracking using a noncontact capacitive sensor  

SciTech Connect (OSTI)

This paper describes the development and use of the Multi-Axis Seam racking (MAST) sensor for tracking seams or other features in real-time. Four independent, spatially-distributed electric fields are used to sense changes in the relative position of the sensor and the workpiece. The MAST sensor is very inexpensive compared with commercially available seam tracking sensors. It can be used in systems to perform cost-effective small-lot manufacturing operations in a faster, more consistent manner. The MAST sensor is used in an automated system for dispensing braze paste during a rocket nozzle fabrication process.

Novak, J.L.; Schmitt, D.J. [Sandia National Labs., Albuquerque, NM (United States); Maslakowski, J. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

1993-08-01T23:59:59.000Z

171

Torque ripple in a Darrieus, vertical axis wind turbine  

SciTech Connect (OSTI)

Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon power quality. An analytical solution characterizing the phenomenon of torque ripple has been obtained which is based upon a Fourier expansion of the time dependent features of the problem. Numerical results for torque ripple, some experimental data, determination of acceptable levels and methods of controlling it, are presented and discussed.

Reuter, R.C. Jr.

1980-09-01T23:59:59.000Z

172

An overview of relativistic hydrodynamics as applied to heavy ion reactions  

SciTech Connect (OSTI)

The application of relativistic hydrodynamics as applied to heavy ions is reviewed. Constraints on the nuclear equation of state, as well as the form of the hydrodynamic equations imposed by causality are discussed. Successes (flow, side-splash, scaling) and shortcomings of one-fluid hydrodynamics are reviewed. Models for pion production within hydrodynamics and reasons for disagreement with experiment are assessed. Finally, the motivations for and the implementations of multi-fluid models are presented. 74 refs., 11 figs.

Strottman, D.D.

1989-01-01T23:59:59.000Z

173

Event-by-event hydrodynamics: A better tool to study the Quark-Gluon plasma  

SciTech Connect (OSTI)

Hydrodynamics has been established as a good tool to describe many data from relativistic heavyion collisions performed at RHIC and LHC. More recently, it has become clear that it is necessary to use event-by-event hydrodynamics (i.e. describe each collision individually using hydrodynamics), an approach first developed in Brazil. In this paper, I review which data require the use of event-by-event hydrodynamics and what more we may learn on the Quark-Gluon Plasma with this.

Grassi, Frederique [Instituto de Fisica, Universidade de Sao Paulo (Brazil)

2013-03-25T23:59:59.000Z

174

Implementations and tests of Godunov-type particle hydrodynamics  

Science Journals Connector (OSTI)

......acceleration and the rate of change of the...prevents particle penetration. Furthermore...level of particle penetration. Additionally...hydrodynamic force and the rate of change of the...constant accretion rate during t collapse...show that particle penetration does not occur in......

S.-H. Cha; A. P. Whitworth

2003-03-21T23:59:59.000Z

175

Smoothed Particle Hydrodynamics in Flood Simulations Michal Chladek  

E-Print Network [OSTI]

Smoothed Particle Hydrodynamics in Flood Simulations Michal Chl´adek Comenius University we present a method for flood simulations of cities and complex models. SPH method is used- lenthaler and Pajarola 2009]. In this paper, we aim at proposing a solution for flood simulation of cities

Durikovic, Roman

176

A new shock-capturing numerical scheme for ideal hydrodynamics  

E-Print Network [OSTI]

We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.

Zuzana Feckova; Boris Tomasik

2015-01-07T23:59:59.000Z

177

A new shock-capturing numerical scheme for ideal hydrodynamics  

E-Print Network [OSTI]

We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.

Feckova, Zuzana

2015-01-01T23:59:59.000Z

178

Effect of Dynamic Stall on the Aerodynamics of Vertical-Axis Wind Turbines  

E-Print Network [OSTI]

Effect of Dynamic Stall on the Aerodynamics of Vertical-Axis Wind Turbines Frank Scheurich of the aerodynamic performance of vertical-axis wind turbines pose a significant challenge for computational fluid of the aerodynamics of a vertical- axis wind turbine that consists of three curved rotor blades that are twisted

McCalley, James D.

179

Experimental investigation of the performance of a diffuser-augmented vertical axis wind turbine  

E-Print Network [OSTI]

Experimental investigation of the performance of a diffuser- augmented vertical axis wind turbine Experimental investigation of the performance of a diffuser-augmented vertical axis wind turbine by Arash The performance of a vertical axis wind turbine with and without a diffuser was studied using direct force

Victoria, University of

180

Coriolis Effect on Dynamic Stall in a Vertical Axis Wind Turbine at Moderate Reynolds Number  

E-Print Network [OSTI]

axis wind turbines (VAWT) offer several advantages over horizontal axis wind turbines (HAWT), namely to yaw wind direction (because they are omnidirectional), and their increased power output in skewed flowCoriolis Effect on Dynamic Stall in a Vertical Axis Wind Turbine at Moderate Reynolds Number Hsieh

Colonius, Tim

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Dual axis translation apparatus and system for translating an optical beam and related method  

DOE Patents [OSTI]

A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

Cassidy, Kelly (Manteca, CA)

1991-01-01T23:59:59.000Z

182

Dynamic behavior analysis for a six axis industrial machining robot  

E-Print Network [OSTI]

The six axis robots are widely used in automotive industry for their good repeatability (as defined in the ISO92983) (painting, welding, mastic deposition, handling etc.). In the aerospace industry, robot starts to be used for complex applications such as drilling, riveting, fiber placement, NDT, etc. Given the positioning performance of serial robots, precision applications require usually external measurement device with complexes calibration procedure in order to reach the precision needed. New applications in the machining field of composite material (aerospace, naval, or wind turbine for example) intend to use off line programming of serial robot without the use of calibration or external measurement device. For those applications, the position, orientation and path trajectory precision of the tool center point of the robot are needed to generate the machining operation. This article presents the different conditions that currently limit the development of robots in robotic machining applications. We ana...

Bisu, Claudiu-Florinel; Gérard, Alain; K'Nevez, Jean-Yves

2012-01-01T23:59:59.000Z

183

Dynamic stall occurrence on a horizontal axis wind turbine blade  

SciTech Connect (OSTI)

Surface pressure data from the National Renewable Energy Laboratory`s ``Combined Experiment`` were analyzed to provide a statistical representation of dynamic stall occurrence on a downwind horizontal axis wind turbine (HAWT). Over twenty thousand blade rotational cycles were each characterized at four span locations by the maximum leading edge suction pressure and by the azimuth, velocity, and yaw at which it occurred. Peak suction values at least twice that seen in static wind tunnel tests were taken to be indicative of dynamic stall. The occurrence of dynamic stall at all but the inboard station (30% span) shows good quantitative agreement with the theoretical limits on inflow velocity and yaw that should yield dynamic stall. Two hypotheses were developed to explain the discrepancy at 30% span. Estimates are also given for the frequency of dynamic stall occurrence on upwind turbines. Operational regimes were identified which minimize the occurrence of dynamic stall events.

Shipley, D.E.; Miller, M.S.; Robinson, M.C. [Colorado Univ., Boulder, CO (United States). Dept. of Aerospace Engineering Sciences

1995-07-01T23:59:59.000Z

184

Dual-axis resonance testing of wind turbine blades  

DOE Patents [OSTI]

An apparatus (100) for fatigue testing test articles (104) including wind turbine blades. The apparatus (100) includes a test stand (110) that rigidly supports an end (106) of the test article (104). An actuator assembly (120) is attached to the test article (104) and is adapted for substantially concurrently imparting first and second forcing functions in first and second directions on the test article (104), with the first and second directions being perpendicular to a longitudinal axis. A controller (130) transmits first and second sets of displacement signals (160, 164) to the actuator assembly (120) at two resonant frequencies of the test system (104). The displacement signals (160, 164) initiate the actuator assembly (120) to impart the forcing loads to concurrently oscillate the test article (104) in the first and second directions. With turbine blades, the blades (104) are resonant tested concurrently for fatigue in the flapwise and edgewise directions.

Hughes, Scott; Musial, Walter; White, Darris

2014-01-07T23:59:59.000Z

185

IR Spectrometer Using 90-degree Off-axis Parabolic Mirrors  

SciTech Connect (OSTI)

A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light ource at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output IR recording camera. With an initial wavelength range of 1500–4500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera array’s sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled into a high-speed detector to verify steady radiance during the gated spectral imaging. Alignment features include tick marks on the prism and parabolic mirrors. This instrument was designed to complement singlepoint pyrometry, which provides continuous time histories of a small collection of spots from shock-heated targets.

Robert M. Malone, Richard, G. Hacking, Ian J. McKenna, and Daniel H. Dolan

2008-09-02T23:59:59.000Z

186

Three-column osteotomies of the lower cervical and upper thoracic spine: comparison of early outcomes, radiographic parameters, and peri-operative complications in 48 patients  

Science Journals Connector (OSTI)

To evaluate and compare early radiographic and clinical outcomes of lower cervical and upper thoracic three-column osteotomies (3CO) for cervicothoracic kyphosis correction.

Alexander A. Theologis; Ehsan Tabaraee; Haruki Funao…

2014-11-01T23:59:59.000Z

187

Galaxies that Shine: radiation-hydrodynamical simulations of disk galaxies  

E-Print Network [OSTI]

Radiation feedback is typically implemented using subgrid recipes in hydrodynamical simulations of galaxies. Very little work has so far been performed using radiation-hydrodynamics (RHD), and there is no consensus on the importance of radiation feedback in galaxy evolution. We present RHD simulations of isolated galaxy disks of different masses with a resolution of 18 pc. Besides accounting for supernova feedback, our simulations are the first galaxy-scale simulations to include RHD treatments of photo-ionisation heating and radiation pressure, from both direct optical/UV radiation and multi-scattered, re-processed infrared (IR) radiation. Photo-heating smooths and thickens the disks and suppresses star formation about as much as the inclusion of ("thermal dump") supernova feedback does. These effects decrease with galaxy mass and are mainly due to the prevention of the formation of dense clouds, as opposed to their destruction. Radiation pressure, whether from direct or IR radiation, has little effect, but ...

Rosdahl, Joakim; Teyssier, Romain; Agertz, Oscar

2015-01-01T23:59:59.000Z

188

Development and Implementation of Radiation-Hydrodynamics Verification Test Problems  

SciTech Connect (OSTI)

Analytic solutions to the radiation-hydrodynamic equations are useful for verifying any large-scale numerical simulation software that solves the same set of equations. The one-dimensional, spherically symmetric Coggeshall No.9 and No.11 analytic solutions, cell-averaged over a uniform-grid have been developed to analyze the corresponding solutions from the Los Alamos National Laboratory Eulerian Applications Project radiation-hydrodynamics code xRAGE. These Coggeshall solutions have been shown to be independent of heat conduction, providing a unique opportunity for comparison with xRAGE solutions with and without the heat conduction module. Solution convergence was analyzed based on radial step size. Since no shocks are involved in either problem and the solutions are smooth, second-order convergence was expected for both cases. The global L1 errors were used to estimate the convergence rates with and without the heat conduction module implemented.

Marcath, Matthew J. [Los Alamos National Laboratory; Wang, Matthew Y. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

189

Hydrodynamic Burnett equations for inelastic Maxwell models of granular gases  

E-Print Network [OSTI]

The hydrodynamic Burnett equations and the associated transport coefficients are exactly evaluated for generalized inelastic Maxwell models. In those models, the one-particle distribution function obeys the inelastic Boltzmann equation, with a velocity-independent collision rate proportional to the $\\gamma$ power of the temperature. The pressure tensor and the heat flux are obtained to second order in the spatial gradients of the hydrodynamic fields with explicit expressions for all the Burnett transport coefficients as functions of $\\gamma$, the coefficient of normal restitution, and the dimensionality of the system. Some transport coefficients that are related in a simple way in the elastic limit become decoupled in the inelastic case. As a byproduct, existing results in the literature for three-dimensional elastic systems are recovered, and a generalization to any dimension of the system is given. The structure of the present results is used to estimate the Burnett coefficients for inelastic hard spheres.

Nagi Khalil; Vicente Garzó; Andrés Santos

2014-05-06T23:59:59.000Z

190

Hydrodynamic instabilities in beryllium targets for the National Ignition Facility  

SciTech Connect (OSTI)

Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

Yi, S. A., E-mail: austinyi@lanl.gov; Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

2014-09-15T23:59:59.000Z

191

Hydrodynamical Simulations of Jet- and Wind-driven Protostellar Outflows  

E-Print Network [OSTI]

We present two-dimensional hydrodynamical simulations of both jet- and wind-driven models for protostellar outflows in order to make detailed comparisons to the kinematics of observed molecular outflows. Comparing the different simulations with observations, we find that some outflows, e.g., HH 212, show features consistent with the jet-driven model, while others, e.g., VLA 05487, are consistent with the wind-driven model.

Chin-Fei Lee; James M. Stone; Eve C. Ostriker; Lee G. Mundy

2001-04-23T23:59:59.000Z

192

Hyperbolic Conservation Laws and Hydrodynamic Limit for Particle Systems  

E-Print Network [OSTI]

We study the following class of scalar hyperbolic conservation laws with discontinuous fluxes: \\partial_t\\rho+\\partial_xF(x,\\rho)=0. The main feature of such a conservation law is the discontinuity of the flux function in the space variable x. Kruzkov's approach for the L1-contraction does not apply since it requires the Lipschitz continuity of the flux function; and entropy solutions even for the Riemann problem are not unique under the classical entropy conditions. On the other hand, it is known that, in statistical mechanics, some microscopic interacting particle systems with discontinuous speed parameter lambda(x), in the hydrodynamic limit, formally lead to scalar hyperbolic conservation laws with discontinuous fluxes of the form: \\partial_t\\rho+\\partial_x(\\lambda(x)h(\\rho))=0. The natural question arises which entropy solutions the hydrodynamic limit selects, thereby leading to a suitable, physical relevant notion of entropy solutions of this class of conservation laws. This paper is a first step and provides an answer to this question for a family of discontinuous flux functions. In particular, we identify the entropy condition for our PDE and proceed to show the well-posedness by combining our existence result with a uniqueness result of Audusse-Perthame (2005) for the family of flux functions; we establish a compactness framework for the hydrodynamic limit of large particle systems and the convergence of other approximate solutions to our PDE, which is based on the notion and reduction of measure-valued entropy solutions; and we finally establish the hydrodynamic limit for a ZRP with discontinuous speed-parameter governed by an entropy solution to our PDE.

Gui-Qiang Chen; Nadine Even; Christian Klingenberg

2007-10-01T23:59:59.000Z

193

Hydrodynamic detonation instability in electroweak and QCD phase transitions  

Science Journals Connector (OSTI)

The hydrodynamic stability of deflagration and detonation bubbles for a first order electroweak and QCD phase transition has been discussed recently with the suggestion that detonations are stable. We examine here the case of a detonation more carefully. We find that in front of the bubble wall perturbations do not grow with time, but behind the wall modes exist which grow exponentially. We briefly discuss the possible meaning of this instability.

Mark Abney

1994-02-15T23:59:59.000Z

194

Relativistic hydrodynamics in the presence of puncture black holes  

SciTech Connect (OSTI)

Many of the recent numerical simulations of binary black holes in vacuum adopt the moving puncture approach. This successful approach avoids the need to impose numerical excision of the black hole interior and is easy to implement. Here we wish to explore how well the same approach can be applied to moving black hole punctures in the presence of relativistic hydrodynamic matter. First, we evolve single black hole punctures in vacuum to calibrate our Baumgarte-Shapiro-Shibata-Nakamura implementation and to confirm that the numerical solution for the exterior spacetime is invariant to any junk (i.e., constraint-violating) initial data employed in the black hole interior. Then we focus on relativistic Bondi accretion onto a moving puncture Schwarzschild black hole as a numerical test bed for our high-resolution shock-capturing relativistic hydrodynamics scheme. We find that the hydrodynamical equations can be evolved successfully in the interior without imposing numerical excision. These results help motivate the adoption of the moving puncture approach to treat the binary black hole-neutron star problem using conformal thin-sandwich initial data.

Faber, Joshua A.; Etienne, Zachariah B.; Shapiro, Stuart L.; Taniguchi, Keisuke [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Baumgarte, Thomas W. [Department of Physics and Astronomy, Bowdoin College, Brunswick, Maine 04011 (United States)

2007-11-15T23:59:59.000Z

195

An Optical Streak Diagnostic for Observing Anode-Cathode Plasmas for Radiographic Source Development  

SciTech Connect (OSTI)

National Security Technologies, LLC, and Sandia National Laboratories are collaborating in the development of pulsed power–driven flash x-ray radiographic sources that utilize high-intensity electron beam diodes. The RITS 6 (Radiographic Integrated Test Stand) accelerator at Sandia is used to drive a self magnetic pinch diode to produce a Bremsstrahlung x-ray source. The high electric fields and current densities associated with these short A-K gap pinch beam diodes present many challenges in diode development. Plasmas generated at both the anode and cathode affect the diode performance, which is manifested in varying spot (source) sizes, total dose output, and impedance profiles. Understanding the nature of these plasmas including closure rates and densities is important in modeling their behavior and providing insight into their mitigation. In this paper we describe a streak camera–based optical diagnostic that is capable of observing and measuring plasma evolution within the A-K gap. By imaging a region of interest onto the input slit of a streak camera, we are able to produce a time-resolved one-dimensional image of the evolving plasma. Typical data are presented.

Droemer, Darryl W. [National Security Technologies, LLC; Crain, Marlon D.; Lare, Gregory A. [National Security Technologies, LLC; Bennett, Nichelle L. [National Security Technologies, LLC; Johnston, Mark D. [Sandia National Laboratories

2013-06-13T23:59:59.000Z

196

National Security, Weapons Science  

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

National Security, Weapons Science National Security, Weapons Science /science-innovation/_assets/images/icon-science.jpg National Security, Weapons Science National security depends on science and technology. The United States relies on Los Alamos National Laboratory for the best of both. No place on Earth pursues a broader array of world-class scientific endeavors. Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) The Dual-Axis Radiographic Hydrodynamic Test Facility at LANL is part of the DOE's stockpile stewardship program. It uses two large X-ray machines to record three-dimensional interior images of materials. In most experiments, materials (including plutonium) undergo hydrodynamic shock to simulate the implosion process in nuclear bombs and/or the effects of severe hydrodynamic stress. The tests are described as "full-scale mockups

197

Control system for a vertical-axis windmill  

DOE Patents [OSTI]

A vertical-axis windmill having a rotating structure is provided with a series of articulated vertical blades whose positions are controlled to maintain a constant RPM for the rotating structure, when wind speed is sufficient. A microprocessor controller is used to process information on wind speed, wind direction and RPM of the rotating structure to develop an electrical signal for establishing blade position. The preferred embodiment of the invention, when connected to a utility grid, is designed to generate 40 kilowatts of power when exposed to a 20 mile per hour wind. The control system for the windmill includes electrical blade actuators that modulate the blades of the rotating structure. Blade modulation controls the blade angle of attack, which in turn controls the RPM of the rotor. In the preferred embodiment, the microprocessor controller provides the operation logic and control functions. A wind speed sensor provides inputs to start or stop the windmill, and a wind direction sensor is used to keep the blade flip region at 90 and 270/sup 0/ to the wind. The control system is designed to maintain constant rotor RPM when wind speed is between 10 and 40 miles per hour.

Brulle, R.V.

1981-09-03T23:59:59.000Z

198

Work-piece alignment for a hybrid multi-axis laser-aided manufacturing system .  

E-Print Network [OSTI]

??"The Laser Aided Manufacturing Process (LAMP) is a multi-axis hybrid manufacturing process comprised of both an additive process, laser deposition, and a subtractive process, CNC… (more)

Panackal, Ajay

2006-01-01T23:59:59.000Z

199

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

E-Print Network [OSTI]

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

Sargsyan, Armen.

2010-01-01T23:59:59.000Z

200

Dynamical density functional theory with hydrodynamic interactions and colloids in unstable traps  

E-Print Network [OSTI]

A density functional theory for colloidal dynamics is presented which includes hydrodynamic interactions between the colloidal particles. The theory is applied to the dynamics of colloidal particles in an optical trap which switches periodically in time from a stable to unstable confining potential. In the absence of hydrodynamic interactions, the resulting density breathing mode, exhibits huge oscillations in the trap center which are almost completely damped by hydrodynamic interactions. The predicted dynamical density fields are in good agreement with Brownian dynamics computer simulations.

M. Rex; H. Loewen

2008-03-13T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Nonlinear dynamic analysis of hydrodynamically-coupled stainless steel structures  

SciTech Connect (OSTI)

Spent nuclear fuel is usually stored temporarily on the site of nuclear power plants. The spent fuel storage racks are nuclear-safety-related stainless steel structures required to be analyzed for seismic loads. When the storage pool is subjected to three-dimensional (3-D) floor seismic excitations, rack modules, stored fuel bundles, adjacent racks and pool walls, and surrounding water are hydrodynamically coupled. Hydrodynamic coupling (HC) significantly affects the dynamic responses of the racks that are free-standing and submerged in water within the pool. A nonlinear time-history dynamic analysis is usually needed to describe the motion behavior of the racks that are both geometrically nonlinear and material nonlinear in nature. The nonlinearities include the friction resistance between the rack supporting legs and the pool floor, and various potential impacts of fuel-rack, rack-rack, and rack-pool wall. The HC induced should be included in the nonlinear dynamic analysis using the added-hydrodynamic-mass concept based on potential theory per the US Nuclear Regulatory Commission (USNRC) acceptance criteria. To this end, a finite element analysis constitutes a feasible and effective tool. However, most people perform somewhat simplified 1-D, or 2-D, or 3-D single rack and 2-D multiple rack analyses. These analyses are incomplete because a 3-D single rack model behaves quite differently from a 2-D mode. Furthermore, a 3-D whole pool multi-rack model behaves differently than a 3-D single rack model, especially when the strong HC effects are unsymmetrical. In this paper 3-D nonlinear dynamic time-history analyses were performed in a more quantitative manner using sophisticated finite element models developed for a single rack as well as all twelve racks in the whole-pool. Typical response results due to different HC effects are determined and discussed.

Zhao, Y. [Battelle, Columbus, OH (United States). Engineering Mechanics Group

1996-12-01T23:59:59.000Z

202

Technical Note: Unsupervised C-arm pose tracking with radiographic fiducial  

SciTech Connect (OSTI)

Purpose: C-arm fluoroscopy reconstruction, such as that used in prostate brachytherapy, requires that the relative poses of the individual C-arm fluoroscopy images must be known prior to reconstruction. Radiographic fiducials can provide excellent C-arm pose tracking, but they need to be segmented in the image. The authors report an automated and unsupervised method that does not require prior segmentation of the fiducial. Methods: The authors compute the individual C-arm poses relative to a stationary radiographic fiducial of known geometry. The authors register a filtered 2D fluoroscopy image of the fiducial to its 3D model by using image intensity alone without prior segmentation. To enhance the C-arm images, the authors investigated a three-step cascade filter and a line enhancement filter. The authors tested the method on a composite fiducial containing beads, straight lines, and ellipses. Ground-truth C-arm pose was provided by a clinically proven method. Results: Using 111 clinical C-arm images and {+-}10 deg. and {+-}10 mm random perturbation around the ground-truth pose, a total of 2775 cases were evaluated. The average rotation and translation errors were 0.62 deg. (STD=0.31 deg.) and 0.72 mm (STD=0.55 mm) for the three-step filter and 0.67 deg. (STD=0.40 deg.) and 0.87 mm (STD=0.27 mm) using the line enhancement filter. Conclusions: The C-arm pose tracking method was sufficiently accurate and robust on human patient data for subsequent 3D implant reconstruction.

Fallavollita, P.; Burdette, E. C.; Song, D. Y.; Abolmaesumi, P.; Fichtinger, G. [Queen's University, Ontario K7L 3N6 (Canada); Acoustic MedSystems Inc., Champaign, Illinois 61820 (United States); Johns Hopkins Hospital, Baltimore, Maryland 21231-2410 (United States); University of British Columbia, Vancouver V6T 1Z4 (Canada); Queen's University, Ontario K7L 3N6 (Canada)

2011-04-15T23:59:59.000Z

203

IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 54, NO. 4, AUGUST 2007 1285 Radiographic Testing of Anomalies in Thick  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 54, NO. 4, AUGUST 2007 1285 Radiographic Testing-flattening, image processing, nondestructive testing, nuclear imaging, radiography, scattering. I. INTRODUCTION A in the context of primary loop piping inspection in pressurized water nuclear reactors. In a more gen- eral way

Robini, Marc - Pôle de Mathématiques, Institut National des Sciences Appliquées de Lyon

204

Aspects of sensory cues and propulsion in marine zooplankton hydrodynamic disturbances.  

E-Print Network [OSTI]

??The hydrodynamic disturbances generated by two types of free-swimming, marine zooplankton were quantified experimentally in the laboratory with a novel, infrared Particle Image Velocimetry (PIV)… (more)

Catton, Kimberly Bernadine

2009-01-01T23:59:59.000Z

205

Numerical and experimental study of hydrodynamics in a compartmented fluidized bed oil palm shell biomass gasifier.  

E-Print Network [OSTI]

??Numerical and experimental studies of hydrodynamic parameters of fluidized beds formed by either a single component system or a binary mixture in a pilot plant… (more)

Wee, Siaw Khur

2011-01-01T23:59:59.000Z

206

Understanding the Hydrodynamics of Swimming: From Fish Fins to Flexible Propulsors for Autonomous  

E-Print Network [OSTI]

Understanding the Hydrodynamics of Swimming: From Fish Fins to Flexible Propulsors for Autonomous. The research effort described here is concerned with developing a maneuvering propulsor for an autonomous

Lauder, George V.

207

E-Print Network 3.0 - astrophysics hydrodynamical flows Sample...  

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

on astrophysical jets P. M. Bellan Summary: shock driven by an out- flow from a young, low mass star. Purely hydrodynamic models in which... Miniconference on astrophysical...

208

Smoothed Particle Hydrodynamics: Things I wish my mother taught me  

E-Print Network [OSTI]

I discuss the key features of Smoothed Particle Hydrodynamics (SPH) as a numerical method - in particular the key differences between SPH and more standard grid based approaches - that are important to the practitioner. These include the exact treatment of advection, the absence of intrinsic dissipation, exact conservation and more subtle properties that arise from its Hamiltonian formulation such as the existence of a minimum energy state for the particles. The implications of each of these are discussed, showing how they can be both advantages and disadvantages.

Price, Daniel J

2011-01-01T23:59:59.000Z

209

WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES  

E-Print Network [OSTI]

1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1 were carried out to study the aerodynamic performance of three vertical axis wind turbines (VAWTs. On the other hand, the characteristics of unsteady flow around the helical wind turbine were studied with a hot

Leu, Tzong-Shyng "Jeremy"

210

Manufacturing Equipment Modeling For a linear axis actuated by an electric motor complete the following  

E-Print Network [OSTI]

Manufacturing Equipment Modeling QUESTION 1 For a linear axis actuated by an electric motor(t). Include the axis disturbance force, but do not include motor electrical dynamics or Coulomb friction For a spindle actuated by an electric motor complete the following: a. Derive a differential equation

Landers, Robert G.

211

Precise Gouging-free Tool Orientations for 5-Axis CNC Machining Yong-Joon Kima  

E-Print Network [OSTI]

Precise Gouging-free Tool Orientations for 5-Axis CNC Machining Yong-Joon Kima , Gershon Elbera-free tool paths for 5-axis CNC machining of freeform NURBS surfaces using flat-end and rounded-end (bull modeling and have been widely used in a variety of applications. Consequently, CNC machining of NURBS

Pottmann, Helmut

212

Dynamic behavior analysis for a six axis industrial machining BISU Claudiu1,a  

E-Print Network [OSTI]

Dynamic behavior analysis for a six axis industrial machining robot BISU Claudiu1,a , CHERIF Mehdi2-yves.knevez@u-bordeaux1.fr Abstract The six axis robots are widely used in automotive industry for their good repeatability (as defined in the ISO92983) (painting, welding, mastic deposition, handling etc

Paris-Sud XI, Université de

213

Two Oppositely Localised Frizzled RNAs as Axis Determinants in a Cnidarian Embryo  

E-Print Network [OSTI]

ascidian and sea urchin embryos, promoting endoderm/mesoderm fates, and in domains offset from the vegetalTwo Oppositely Localised Frizzled RNAs as Axis Determinants in a Cnidarian Embryo Tsuyoshi Momose) Two oppositely localised Frizzled RNAs as axis determinants in a cnidarian embryo. PLoS Biol 5(4): e70

Villefranche sur mer

214

Near wake properties of horizontal axis marine current L. Myers and A.S. Bahaj  

E-Print Network [OSTI]

1 Near wake properties of horizontal axis marine current turbines L. Myers and A.S. Bahaj wake region of a tidal current turbine is strongly driven by the combined wake of the device support-scale horizontal axis turbine has been have been measured in a large water channel facility. A downstream map

Quartly, Graham

215

Comparison of Different Approaches for the Calculation of Projective Symmetry or the Axis of a SHGC  

E-Print Network [OSTI]

Comparison of Different Approaches for the Calculation of Projective Symmetry or the Axis of a SHGC;Comparison of Different Approaches for the Calculation of Projective Symmetry or the Axis of a SHGC Sven]. And although the projections of straight homogeneous generalised cylinders (SHGC) generally exhibit no symmetry

Hamburg,.Universität

216

CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS J. C. Sprott  

E-Print Network [OSTI]

CYCLOTRON HEATING NFR THE MULTIPOLE B = 0 AXIS by J. C. Sprott November 1973 PLP 536 Plasma Studies of the author and major professor. #12;Ion and Electron Cyclotron heating rates in multipoles are generally = 0 axis in a multipole. The average cyclotron heating rate is given by d--= dt where TIB G 0 = TI

Sprott, Julien Clinton

217

CTAX: the US/Japan Cold Neutron Triple-Axis Spectromete at HFIR | ORNL  

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

CTAX-US/Japan Cold Neutron Triple-Axis Spectrometer CTAX-US/Japan Cold Neutron Triple-Axis Spectrometer CTAX US/Japan Cold Neutron Triple-Axis Spectrometer (CG-4C). (larger image) The U.S.-Japan Cold Neutron Triple-Axis Spectrometer (CTAX) is a conventional triple-axis spectrometer with variable incident energy and variable monochromator-sample and sample-analyzer distances. The cold guide 4 bender and guide hall shielding reduce background levels at CG-4C, and the 15-cm-tall guide profile is well exploited by CG-4C's vertically focusing monochromator (PG 002). To enhance accommodation of strong magnetic fields at the sample position and to simplify future polarization analysis, the amount of ferromagnetic material has been minimized in the construction of this instrument. CG-4C is a collaboration of Oak Ridge National Laboratory, the Neutron

218

Hydrodynamic model for electron-hole plasma in graphene  

E-Print Network [OSTI]

We propose a hydrodynamic model describing steady-state and dynamic electron and hole transport properties of graphene structures which accounts for the features of the electron and hole spectra. It is intended for electron-hole plasma in graphene characterized by high rate of intercarrier scattering compared to external scattering (on phonons and impurities), i.e., for intrinsic or optically pumped (bipolar plasma), and gated graphene (virtually monopolar plasma). We demonstrate that the effect of strong interaction of electrons and holes on their transport can be treated as a viscous friction between the electron and hole components. We apply the developed model for the calculations of the graphene dc conductivity, in particular, the effect of mutual drag of electrons and holes is described. The spectra and damping of collective excitations in graphene in the bipolar and monopolar limits are found. It is shown that at high gate voltages and, hence, at high electron and low hole densities (or vice-versa), the excitations are associated with the self-consistent electric field and the hydrodynamic pressure (plasma waves). In intrinsic and optically pumped graphene, the waves constitute quasineutral perturbations of the electron and hole densities (electron-hole sound waves) with the velocity being dependent only on the fundamental graphene constants.

D. Svintsov; V. Vyurkov; S. Yurchenko; T. Otsuji; V. Ryzhii

2012-01-03T23:59:59.000Z

219

A CLASS OF PHYSICALLY MOTIVATED CLOSURES FOR RADIATION HYDRODYNAMICS  

SciTech Connect (OSTI)

Radiative transfer and radiation hydrodynamics use the relativistic Boltzmann equation to describe the kinetics of photons. It is difficult to solve the six-dimensional time-dependent transfer equation unless the problem is highly symmetric or in equilibrium. When the radiation field is smooth, it is natural to take angular moments of the transfer equation to reduce the degrees of freedom. However, low order moment equations contain terms that depend on higher order moments. To close the system of moment equations, approximations are made to truncate this hierarchy. Popular closures used in astrophysics include flux-limited diffusion and the M{sub 1} closure, which are rather ad hoc and do not necessarily capture the correct physics. In this paper, we propose a new class of closures for radiative transfer and radiation hydrodynamics. We start from a different perspective and highlight the consistency of a fully relativistic formalism. We present a generic framework to approximate radiative transfer based on relativistic Grad's moment method. We then derive a 14-field method that minimizes unphysical photon self-interaction.

Chan, Chi-kwan, E-mail: ckchan@cfa.harvard.edu [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-02-01T23:59:59.000Z

220

Hydrodynamic analysis of direct steam generation solar collectors  

SciTech Connect (OSTI)

Direct steam generation collectors are considered with the aim to improve the performance of a parabolic trough collector leading to a reduction of operating costs of solar electric generation systems. In this study a hydrodynamic steady state model is developed and linked with a thermal model to optimize the performance of once-through direct steam generation solar collectors. The hydrodynamic model includes flow pattern classification and a pressure drop model. Flow pattern maps for typical DSG collectors with horizontal and inclined absorber tubes are generated to investigate the variation of flow conditions with radiation level, tube diameter, tube length and flow rate. Two-phase flow frictional pressure drop correlations for the range of operating conditions in a DSG collector are selected from the wide range of published correlations by comparison with experimental data for typical steam-water flow conditions in a DSG collector. Pressure drop is calculated for different operating conditions for both horizontal and inclined solar absorber tubes. Alternative operational strategies are evaluated to achieve optimum performance of a direct steam generation collector at different radiation levels.

Odeh, S.D.; Behnia, M.; Morrison, G.L.

2000-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Radiation Hydrodynamics Test Problems with Linear Velocity Profiles  

SciTech Connect (OSTI)

As an extension of the works of Coggeshall and Ramsey, a class of analytic solutions to the radiation hydrodynamics equations is derived for code verification purposes. These solutions are valid under assumptions including diffusive radiation transport, a polytropic gas equation of state, constant conductivity, separable flow velocity proportional to the curvilinear radial coordinate, and divergence-free heat flux. In accordance with these assumptions, the derived solution class is mathematically invariant with respect to the presence of radiative heat conduction, and thus represents a solution to the compressible flow (Euler) equations with or without conduction terms included. With this solution class, a quantitative code verification study (using spatial convergence rates) is performed for the cell-centered, finite volume, Eulerian compressible flow code xRAGE developed at Los Alamos National Laboratory. Simulation results show near second order spatial convergence in all physical variables when using the hydrodynamics solver only, consistent with that solver's underlying order of accuracy. However, contrary to the mathematical properties of the solution class, when heat conduction algorithms are enabled the calculation does not converge to the analytic solution.

Hendon, Raymond C. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

222

Hydrodynamics of rapidly rotating superfluid neutron stars with mutual friction  

E-Print Network [OSTI]

We study time evolutions of superfluid neutron stars, focussing on the nature of the oscillation spectrum, the effect of mutual friction force on the oscillations and the hydrodynamical spin-up phase of pulsar glitches. We linearise the dynamical equations of a Newtonian two-fluid model for rapidly rotating backgrounds. In the axisymmetric equilibrium configurations, the two fluid components corotate and are in beta-equilibrium. We use analytical equations of state that generate stratified and non-stratified stellar models, which enable us to study the coupling between the dynamical degrees of freedom of the system. By means of time evolutions of the linearised dynamical equations, we determine the spectrum of axisymmetric and non-axisymmetric oscillation modes, accounting for the contribution of the gravitational potential perturbations, i.e. without adopting the Cowling approximation. We study the mutual friction damping of the superfluid oscillations and consider the effects of the non-dissipative part of the mutual friction force on the mode frequencies. We also provide technical details and relevant tests for the hydrodynamical model of pulsar glitches discussed by Sidery, Passamonti and Andersson (2010). In particular, we describe the method used to generate the initial data that mimic the pre-glitch state, and derive the equations that are used to extract the gravitational-wave signal.

A. Passamonti; N. Andersson

2010-04-26T23:59:59.000Z

223

EXPLICIT-IMPLICIT SCHEME FOR RELATIVISTIC RADIATION HYDRODYNAMICS  

SciTech Connect (OSTI)

We propose an explicit-implicit scheme for numerically solving special relativistic radiation hydrodynamic equations, which ensures a conservation of total energy and momentum (matter and radiation). In our scheme, zeroth and first moment equations of the radiation transfer equation are numerically solved without employing a flux-limited diffusion approximation. For an hyperbolic term, of which the timescale is the light crossing time when the flow velocity is comparable to the speed of light, is explicitly solved using an approximate Riemann solver. Source terms describing an exchange of energy and momentum between the matter and the radiation via the gas-radiation interaction are implicitly integrated using an iteration method. The implicit scheme allows us to relax the Courant-Friedrichs-Lewy condition in optically thick media, where heating/cooling and scattering timescales could be much shorter than the dynamical timescale. We show that our numerical code can pass test problems of one- and two-dimensional radiation energy transport, and one-dimensional radiation hydrodynamics. Our newly developed scheme could be useful for a number of relativistic astrophysical problems. We also discuss how to extend our explicit-implicit scheme to the relativistic radiation magnetohydrodynamics.

Takahashi, Hiroyuki R. [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)] [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Ohsuga, Ken; Tomida, Kengo [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)] [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Sekiguchi, Yuichiro [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)] [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Inoue, Tsuyoshi, E-mail: takahashi@cfca.jp [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Sagamihara 229-8558 (Japan)] [Department of Physics and Mathematics, Aoyama Gakuin University, Fuchinobe, Sagamihara 229-8558 (Japan)

2013-02-20T23:59:59.000Z

224

Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems  

E-Print Network [OSTI]

Finite element simulations of hydrodynamic trapping in microfluidic particle- trap array systems;Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems Xiaoxiao) simulation is a powerful tool in the design and implementation of microfluidic systems, especially

Nehorai, Arye

225

Video Article A Microfluidic-based Hydrodynamic Trap for Single Particles  

E-Print Network [OSTI]

Video Article A Microfluidic-based Hydrodynamic Trap for Single Particles Eric M. Johnson). A Microfluidic-based Hydrodynamic Trap for Single Particles. JoVE. 47. http://www.jove.com/details.php?id=2517 and biology ranging from the molecular to cellular level. In this article, we introduce a new microfluidic

Schroeder, Charles

226

COURSE INFORMATION AND OUTLINE ORE 609 -HYDRODYNAMICS OF FLUID-BODY INTERACTION  

E-Print Network [OSTI]

IN THE ORE LIBRARY · Sarpkaya and Isaacson: Mechanics of Wave Forces on Offshore Structures · Newman: Marine Hydrodynamics · Currie: Fundamental Mechanics of Fluids · Ippen: Estuary and Coastline Hydrodynamics · Mei: The Applied Dynamics of Ocean Surface Waves · Abramowitz and Stegun: Handbook of Mathematical Functions

Frandsen, Jannette B.

227

The Hydrodynamics of Flow Stimuli Matthew J. McHenry and James C. Liao  

E-Print Network [OSTI]

motion. Although this motion can be highly complex, it emerges from just two fundamental fluid forces, Springer Handbook of Auditory Research 48, DOI 10.1007/2506_2013_13, © Springer Science+Business Media, LLC 2013 #12;2 Hydrodynamic Principles Hydrodynamic theory is concerned with the forces generated by water

McHenry, Matt

228

Hydrodynamic starvation in first-feeding larval fishes Victor Chinaa,b  

E-Print Network [OSTI]

Hydrodynamic starvation in first-feeding larval fishes Victor Chinaa,b and Roi Holzmana,b,1 York, NY, and approved April 24, 2014 (received for review December 16, 2013) Larval fishes suffer under high prey densities. Our results provide a hydrodynamic perspective on feeding of larval fishes

Einat, Aharonov

229

Exploration for stratigraphic traps in a mature hydrodynamic setting, Williston Basin, North Dakota  

SciTech Connect (OSTI)

Hydrodynamic effects on oil accumulations generally can be recognized at an early stage of exploration, but become of critical importance with increased drilling and discoveries. At the mature stage, hydrodynamic concepts readily can be applied in exploration and development to reduce risk and to increase success ratios. The south flank of the Williston basin is an example of a mature area with significant hydrodynamic effects on accumulation. Early exploration was aimed at stratigraphic traps in the Mission Canyon Formation but the development of major fields showed that all are strongly influenced by hydrodynamic flow and some may be largely independent of porosity pinchouts. Examples of hydrodynamic effects are illustrated by the Billings Nose fields, and the Elkhorn Ranch and Knutson fields. These accumulations have hydrodynamic gradients on the order of 20 ft/mi (4 m/km) or more; tilted oil-water contacts with gradient of 30 to 50 ft/mi (6 to 10 m/km); displacement of oil downdip to the northeast; and variable formation water salinities that range from nearly fresh to highly saline. Some producing zones have been described as purely hydrodynamic traps, lacking both structural and stratigraphic closure. Future success will depend on applying hydrodynamic concepts in exploration and development, and prediction methods are illustrated by possible extensions to existing one-well fields. Simple graphic techniques can estimate the limits of production before drilling, but a knowledge of local structure is most important to the interpretation.

Berg, R.R. (Texas A and M Univ., College Station (USA))

1990-05-01T23:59:59.000Z

230

Three Dimensional Numerical General Relativistic Hydrodynamics ; 1, Formulations, Methods, and Code Tests  

E-Print Network [OSTI]

This is the first in a series of papers on the construction and validation of a three-dimensional code for general relativistic hydrodynamics, and its application to general relativistic astrophysics. This paper studies the consistency and convergence of our general relativistic hydrodynamic treatment and its coupling to the spacetime evolutions described by the full set of Einstein equations with a perfect fluid source. The numerical treatment of the general relativistic hydrodynamic equations is based on high resolution shock capturing schemes. These schemes rely on the characteristic information of the system. A spectral decomposition for general relativistic hydrodynamics suitable for a general spacetime metric is presented. Evolutions based on three different approximate Riemann solvers coupled to four different discretizations of the Einstein equations are studied and compared. The coupling between the hydrodynamics and the spacetime (the right and left hand side of the Einstein equations) is carried ou...

Font, J A; Suen, W; Tobias, M

2000-01-01T23:59:59.000Z

231

Annual performance prediction for off-axis aligned Lugo heliostats at Solar Two  

SciTech Connect (OSTI)

The DELSOL computer code was used to model the annual Performance for numerous off-axis alignments of the Lugo heliostats located at the Solar Two site in Dagget, California. Recommended canting times are presented for the Lugo heliostats based upon their location in the field. Predicted annual performance of an off-axis alignment was actually higher than for on-axis alignment in some cases, and approximately equal if the recommended times are used. The annual performances of Solar One heliostats located nearby were also calculated, and illustrated the poorer performance expected of the Lugo heliostats.

Jones, S.A.

1996-02-01T23:59:59.000Z

232

Hydrodynamic forces due to waves and a current induced on a pipeline placed in an open trench  

E-Print Network [OSTI]

repairs and avoid environmental impacts resulting from pipeline failures. 8. Objectives of the Research Trenched pipelines are exposed to less hydrodynamic forces than pipelines placed on the sea floor. The hydrodynamic force variation for the pipes... repairs and avoid environmental impacts resulting from pipeline failures. 8. Objectives of the Research Trenched pipelines are exposed to less hydrodynamic forces than pipelines placed on the sea floor. The hydrodynamic force variation for the pipes...

Lee, Jaeyoung

2012-06-07T23:59:59.000Z

233

Energy dependent growth of the nucleon and hydrodynamic initial conditions  

E-Print Network [OSTI]

Due to gluon saturation, the growth of the inelastic nucleon-nucleon cross section with increasing collision energy sqrt(s) results in a broadening of the nucleon's density distribution in position space. This leads to a natural smoothing of the initial energy density distribution in the transverse plane of the matter created near midrapidity in heavy-ion collisions. We study this effect for fluctuating initial conditions generated with the Monte Carlo Kharzeev-Levin-Nardi (MC-KLN) model for Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). We argue that at the LHC viscous hydrodynamics is applicable at earlier times than at RHIC, not only because of the higher temperature but also since the length scale over which the initial pressure fluctuates increases with collision energy.

Ulrich W. Heinz; J. Scott Moreland

2011-10-19T23:59:59.000Z

234

A method for desalination and water remediation by hydrodynamic cavitation  

Science Journals Connector (OSTI)

Water is becoming an increasingly valuable commodity with population growth demanding more and more amounts of this limited resource. Increased efforts are directed toward recycling and remediation as well as desalination of the large quantities of seawater available. Dr. Bertwin Langenecker was a pioneer in utilizing hydrodynamic cavitation in a variety of applications that would remove dissolved solids from water and other liquids. His combination of intense cavitation using a rotor-stator combination as well as simultaneously adding an adsorbent demonstrated impressive results in desalination and waste water remediation. In this presentation a description will be given of Dr. Langenecker’s technology as well as a sampling of some of his most impressive results. Speculations as to why this approach works as well as it does will be presented.

2013-01-01T23:59:59.000Z

235

A method for desalination and water remediation by hydrodynamic cavitation  

Science Journals Connector (OSTI)

Water is becoming an increasingly valuable commodity with population growth demanding more and more amounts of this limited resource. Increased efforts are directed toward recycling and remediation as well as desalination of the large quantities of seawater available. Dr. Bertwin Langenecker was a pioneer in utilizing hydrodynamic cavitation in a variety of applications that would remove dissolved solids from water and other liquids. His combination of intense cavitation using a rotor-stator combination as well as simultaneously adding an adsorbent demonstrated impressive results in desalination and waste water remediation. In this presentation a description will be given of Dr. Langenecker's technology as well as a sampling of some of his most impressive results. Speculations as to why this approach works as well as it does will be presented.

Lawrence A. Crum; Michael Skinner; Scott Zeilinger

2013-01-01T23:59:59.000Z

236

Hydrodynamic Scaling Analysis of Nuclear Fusion in Hot Plasma  

E-Print Network [OSTI]

Proton beams generated by ultraintense laser pulse irradiations have potential applications in industry and in medicine. However, the laser pulse parameters are currently not optimized for practical applications. We discuss scaling laws of fusion yields generated by laser-plasma interactions. The yields are found to scale as a function of the laser power. The origin of the scaling law in the laser driven fusion yield is derived in terms of hydrodynamical scaling and it is attributed to the laser power dependence of three terms: the reaction rate, the density of the plasma and the pro- jected range of the plasma particle in the medium. The resulting scaling relations have a powerful predictive power that enables estimating the fusion yield for a nuclear reaction which has not been investigated by means of the laser accelerated ion beams.

Kimura, Sachie

2011-01-01T23:59:59.000Z

237

Heavy-ion-beam–induced hydrodynamic effects in solid targets  

Science Journals Connector (OSTI)

It is expected that after the completion of a new high current injector, the heavy-ion synchrotron (SIS) at the Gesellschaft für Schwerionforschung (GSI) Darmstadt will accelerate U+28 ions to energies of the order of 200 MeV/u. The use of a powerful rf buncher will reduce the pulse length to about 50 ns, and employment of a multiturn injection scheme will provide 2×1011 particles in the beam that correspond to a total energy of the order of 1 kJ. This upgrade of the SIS, hopefully, will be completed by the end of the year 2001. These beam parameters lead to a specific power deposition of the order of 1–2 TW/g in solid matter that will provide temperatures of about 10 eV. Such low specific power deposition will induce hydrodynamic effects in solid materials, and one may design appropriate beam-target interaction experiments that could be used to investigate the equation of state of matter under extreme conditions. The purpose of this paper is to propose suitable target designs with optimized parameters for the future GSI experiments with the help of one and two-dimensional hydrodynamic simulations. Cylindrical geometry is the natural geometry for highly focused ion beams, and therefore cylindrical targets are the most appropriate for this type of interaction experiments. The numerical simulations presented in this paper show that one can experimentally measure the characteristic sound speed in beam heated targets which is an important physical parameter. Moreover, one can study the propagation of ion-beam-induced shock waves in the solid materials. Different values for the specific power deposition, namely, 10, 25, 50, and 100 kJ/g, have been used. In some cases the pulse length is assumed to be 40 ns while in others it is considered to be 50 ns. Various materials including lead, aluminum, and solid neon have been used.

N. A. Tahir, D. H. H. Hoffmann, J. A. Maruhn, P. Spiller, and R. Bock

1999-10-01T23:59:59.000Z

238

Statistical inversion for medical x-ray tomography with few radiographs: II. Application to dental radiology  

Science Journals Connector (OSTI)

Diagnostic and operational tasks in dental radiology often require three-dimensional information that is difficult or impossible to see in a projection image. A CT-scan provides the dentist with comprehensive three-dimensional data. However, often CT-scan is impractical and, instead, only a few projection radiographs with sparsely distributed projection directions are available. Statistical (Bayesian) inversion is well-suited approach for reconstruction from such incomplete data. In statistical inversion, a priori information is used to compensate for the incomplete information of the data. The inverse problem is recast in the form of statistical inference from the posterior probability distribution that is based on statistical models of the projection data and the a priori information of the tissue. In this paper, a statistical model for three-dimensional imaging of dentomaxillofacial structures is proposed. Optimization and MCMC algorithms are implemented for the computation of posterior statistics. Results are given with in vitro projection data that were taken with a commercial intraoral x-ray sensor. Examples include limited-angle tomography and full-angle tomography with sparse projection data. Reconstructions with traditional tomographic reconstruction methods are given as reference for the assessment of the estimates that are based on the statistical model.

V Kolehmainen; S Siltanen; S Järvenpää; J P Kaipio; P Koistinen; M Lassas; J Pirttilä; E Somersalo

2003-01-01T23:59:59.000Z

239

Design, fabrication, and testing of a three-dimensional monolithic compliant six-axis nanopositioner  

E-Print Network [OSTI]

The purpose of this research was to demonstrate the feasibility for creating a three-dimensional monolithic compliant six-axis nanopositioner. Much of this work was based off of the original two-dimensional HexFlex manipulator ...

Labuz, James (James R.)

2006-01-01T23:59:59.000Z

240

Advanced Technology Solar Telescope 4.2 m Off-axis Primary Mirror Fabrication  

Science Journals Connector (OSTI)

Advanced optical surfacing technologies are applied for the Advanced Technology Solar Telescope 4.2 m off-axis primary mirror fabrication. A newly developed Stressed lap and IR...

Kim, Dae Wook; Oh, Chang Jin; Su, Peng; Burge, James H

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

E-Print Network 3.0 - axis neutron spectrometer Sample Search...  

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

results for: axis neutron spectrometer Page: << < 1 2 3 4 5 > >> 1 For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Summary:...

242

Regulation Of Fshr And SF-1 In The Hypothalamus-Pituitary-Gonadal (HPG) Axis.  

E-Print Network [OSTI]

Mammalian reproduction is highly dependent on the delicate balance of signals within the hypothalamic-pituitary-gonadal (HPG) axis that maintains proper endocrine environment. One of the key signals is the pituitary ...

George, Jitu Wilson

2013-08-31T23:59:59.000Z

243

Analysis and Strategies for Five-Axis Near-Dry EDM Milling.  

E-Print Network [OSTI]

??Strategies for precision five-axis near-dry electric discharge machining (EDM) milling are investigated. By understanding the material removal process behind near-dry EDM milling, its performance can… (more)

Fujiki, Masahiro

2009-01-01T23:59:59.000Z

244

A process planning strategy for multi-axis hybrid manufacturing process  

Science Journals Connector (OSTI)

This paper outlines a process planning strategy for a multi-axis hybrid manufacturing process that includes a metal deposition system and a multi-axis CNC machining system to rapidly manufacture precision metal parts. Different from the current layered manufacturing processes of which build direction is fixed throughout the process, the orientation of the part can affect the non-support buildability in the multi-axis hybrid manufacturing process. However, each orientation that satisfies the buildability and other constraints may not be unique. In this case, the final optimal orientation is determined based on build time. The build time computation algorithm for multi-axis hybrid system is presented in this paper. To speed up the exhaustive search for the optimal orientation, a multi-stage algorithm is developed to reduce the search space. A case study is used as an example to show the process planning strategy.

Jun Zhang; Jianzhong Ruan; Frank Liou

2013-01-01T23:59:59.000Z

245

Modeling of multiple-optical-axis pattern-integrated interference lithography systems.  

E-Print Network [OSTI]

??The image quality and collimation in a multiple-optical-axis pattern-integrated interference lithography system are evaluated for an elementary optical system composed of single-element lenses. Image quality… (more)

Sedivy, Donald E.

2014-01-01T23:59:59.000Z

246

Study of Reflected Shock Wave Perturbations at the Central Axis of Dense Plasma Column in a Plasma Focus  

Science Journals Connector (OSTI)

When the shock front (SF) hits the central axis of plasma focus device, a reflected shock moves radially outwards...

Morteza Habibi

2011-12-01T23:59:59.000Z

247

Ball nose milling cutter radius compensation in Z axis for CNC  

Science Journals Connector (OSTI)

A new AutoCAD/VisualLISP based method to substitute the 3D tool radius compensation in Z axis for CNC milling processes is here described. Specific features of VisualLISP programming language combined with AutoCAD facilities are used to gather the data ... Keywords: AutoCAD VisualLISP, CNC milling, Z axis compensation, complex shaped parts, tool radius compensation

Dragoi Mircea Viorel

2009-02-01T23:59:59.000Z

248

FSI Modeling of Vertical-Axis Wind Turbines Y. Bazilevs, A. Korobenko, X. Deng, and J. Yan  

E-Print Network [OSTI]

FSI Modeling of Vertical-Axis Wind Turbines Y. Bazilevs, A. Korobenko, X. Deng, and J. Yan-dependent aerodynamics and fluid-structure interaction (FSI) simula- tions of a Darrieus-type vertical-axis wind turbine compared to the vertical-axis wind turbine (VAWT) designs. However, smaller-size VAWTs are more suitable

Dabiri, John O.

249

Proto-Model of an Infrared Wide-Field Off-Axis Telescope  

E-Print Network [OSTI]

We develop a proto-model of an off-axis reflective telescope for infrared wide-field observations based on the design of Schwarzschild-Chang type telescope. With only two mirrors, this design achieves an entrance pupil diameter of 50 mm and an effective focal length of 100 mm. We can apply this design to a mid-infrared telescope with a field of view of 8 deg X 8 deg. In spite of the substantial advantages of off-axis telescopes in the infrared compared to refractive or on-axis reflective telescopes, it is known to be difficult to align the mirrors in off-axis systems because of their asymmetric structures. Off-axis mirrors of our telescope are manufactured at the Korea Basic Science Institute (KBSI). We analyze the fabricated mirror surfaces by fitting polynomial functions to the measured data. We accomplish alignment of this two-mirror off-axis system using a ray tracing method. A simple imaging test is performed to compare a pinhole image with a simulated prediction.

Kim, Sanghyuk; Chang, Seunghyuk; Kim, Geon Hee; Yang, Sun Choel; Kim, Myung Sang; Lee, Sungho; Lee, Hanshin; 10.5303/JKAS.2010.43.5.169

2010-01-01T23:59:59.000Z

250

Design and implementation of five-axis transformation function in CNC system  

Science Journals Connector (OSTI)

Abstract To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle-tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP (rotation tool center point control) and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software structure, the instructions with respect to the cutter’s position and orientation can be directly carried out in the CNC system.

Feng Wang; Hu Lin; Liaomo Zheng; Lei Yang; Jinjin Feng; Han Zhang

2014-01-01T23:59:59.000Z

251

Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine  

SciTech Connect (OSTI)

The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.

Roald, L.; Jonkman, J.; Robertson, A.

2014-05-01T23:59:59.000Z

252

BOGlanl.working.indd  

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

Delivering Excellence in Delivering Excellence in National Security Science 2010 Board of Governors Annual Report Los Alamos National Security, LLC Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for DOE's National Nuclear Security Administration LANS BOARD OF GOVERNORS ANNUAL REPORT FY10 Significant Accomplishments ----------- 4 Targeted Investing for the Future ------------ 5 Creating Our Future ----------------- 6 Enabling Our Mission ----------------12 Outreach and Community Commitment ---------13 2010 LANS Board of Governors ------------14 Contents Front cover In FY10, the Laboratory's Dual Axis Radiographic Hydrodynamic Test (DARHT) facility completed four successful two axis, multi-frame hydrodynamic tests. Here, Terry Priestley inspects components on

253

A Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially...  

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

A Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially Dependent Viscosity Authors: Martys, N.S., George, W.L., Chun, B., Lootens, D. A smoothed particle...

254

Hydrodynamic Model with Binary Particle Diameters to Predict Axial Voidage Profile in a CFB Combustor  

Science Journals Connector (OSTI)

A hydrodynamic model with binary particle diameters was developed to better predict axial voidage profile in a CFB combustor. In the model, the CFB is regarded as a superposition of two ... field data of voidage ...

J. J. Li; H. Zhang; H. R. Yang; Y. X. Wu…

2010-01-01T23:59:59.000Z

255

Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel  

E-Print Network [OSTI]

Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow

Aussillous, Pascale

256

Effect of More Accurate Hydrodynamic Modeling on Calculating Critical Nonlinear Ship Rolling Response  

Science Journals Connector (OSTI)

It is well known in the marine hydrodynamics field that the radiated wave force is frequency dependent. However, much work in the nonlinear marine dynamical systems field has assumed frequency independence or a c...

Srinivas Vishnubhotla; Jeffrey Falzarano

2009-01-01T23:59:59.000Z

257

Hydrodynamic effects of leading-edge tubercles on control surfaces and in flapping foil propulsion  

E-Print Network [OSTI]

This thesis investigates the hydrodynamic effects of biologically-inspired leading-edge tubercles. Two complementary studies examine the performance of three-dimensional hydrofoils based on the pectoral flippers of the ...

Stanway, Michael Jordan

2008-01-01T23:59:59.000Z

258

Experimental hydrodynamics of spherical projectiles impacting on a free surface using high speed imaging techniques  

E-Print Network [OSTI]

This thesis looks at the hydrodynamics of spherical projectiles impacting the free surface using a unique experimental WebLab facility. Experiments were performed to determine the force impact coefficients of spheres and ...

Laverty, Stephen Michael

2005-01-01T23:59:59.000Z

259

Shape-Controlled Synthesis of Hybrid Nanomaterials via Three-Dimensional Hydrodynamic Focusing  

Science Journals Connector (OSTI)

Shape-Controlled Synthesis of Hybrid Nanomaterials via Three-Dimensional Hydrodynamic Focusing ... Components of this work were conducted at the Penn State node of the NSF-funded National Nanotechnology Infrastructure Network. ...

Mengqian Lu; Shikuan Yang; Yi-Ping Ho; Christopher L. Grigsby; Kam W. Leong; Tony Jun Huang

2014-09-30T23:59:59.000Z

260

CFD study of hydrodynamic signal perception by fish using the lateral line system  

E-Print Network [OSTI]

The lateral line system on fish has been found to aid in schooling behavior, courtship communication, active and passive hydrodynamic imaging, and prey detection. The most widely used artificial prey stimulus has been the ...

Rapo, Mark Andrew

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Statistical Estimation of Two-Body Hydrodynamic Properties Using System Identification  

E-Print Network [OSTI]

information concerning the response characteristics of such systems. The current study demonstrates that the analysis of these data using a combination of statistical tools and system identification techniques can efficiently recover the main hydrodynamic...

Xie, Chen

2010-01-14T23:59:59.000Z

262

A concept of power generator using wind turbine, hydrodynamic retarder, and organic Rankine cycle drive  

Science Journals Connector (OSTI)

This paper describes a concept of electric power generating system that uses a wind turbine to generate kinetic energy which converts heat through a hydrodynamic retarder. The heat so generated is utilized to drive an organic Rankine cycle that converts thermal energy into electricity power for continuous and undisrupted supply during the year. A hydrodynamic retarder converts kinetic energy into heat through hot fluid by directing the flow of the fluid into the hydrodynamic retarder in a manner that resists rotation of blades of the wind turbine. The hot fluid circulating in the hydrodynamic retarder is a thermal heat source for vapor regeneration of organic heat exchange fluid mixture(s) used in the Rankine cycle. The expansion of the organic heat exchange fluid gets converted into rotation of the generator rotor.

Samuel Sami

2013-01-01T23:59:59.000Z

263

Volumetric analysis of fish swimming hydrodynamics using synthetic aperture particle image velocimetry  

E-Print Network [OSTI]

Abstract This thesis details the implementation of a three-dimensional PIV system to study the hydrodynamics of freely swimming Giant Danio (Danio aequipinnatus). Volumetric particle fields are reconstructed using synthetic ...

Mendelson, Leah Rose

2013-01-01T23:59:59.000Z

264

Impact of Channelization on Oyster Production: A Hydrodynamic-Oyster Population Model for Galveston Bay, Texas  

Science Journals Connector (OSTI)

A hydrodynamic-oyster population dynamics model was developed to assess the effect of a change in ship channel configuration under different freshwater inflow regimes and different future hydrologies on oyster (C...

John M. Klinck; Eileen E. Hofmann; Eric N. Powell…

2002-12-01T23:59:59.000Z

265

Simulation and Optimization of DPP Hydrodynamics and Radiation Transport for EUV Lithography Devices  

E-Print Network [OSTI]

be used to study the hydrodynamics and radiation in two-gas mixtures of dense plasma focus (DPF) and z the HEIGHTS- EUV package are schematically shown in Figure 1: a) A dense plasma focus device, b) A hollow

Harilal, S. S.

266

The role of hydrodynamic interactions in the dynamics and viscoelasticity of actin networks  

E-Print Network [OSTI]

Actin, the primary component of the cytoskeleton, is the most studied semi-flexible filament, yet its dynamics remains elusive. We show that hydrodynamic interactions (HIs) significantly alter the time scale of actin ...

Karimi, Reza, Ph. D. Massachusetts Institute of Technology

2012-01-01T23:59:59.000Z

267

Numerical heat conduction in hydrodynamical models of colliding hypersonic flows  

E-Print Network [OSTI]

Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the postshock gas of one flow behaves quasi-adiabatically while the postshock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-he...

Parkin, E R

2010-01-01T23:59:59.000Z

268

Computer-aided design (CAD) of full hydrodynamic journal bearings  

Science Journals Connector (OSTI)

Since the equations involved in solving bearing problems are tedious to work with, calculations are most easily made by the use of bearing performance charts. However, the design of journal bearings is still a relatively cumbersome iterative process that involves the use of various data charts and tables, thus leading to time consuming and less accurate results. Therefore, a complete computer-aided design (CAD) procedure covering the basic methods for designing a full hydrodynamic journal bearing of finite length is developed and presented. The theoretical data and relevant empirical charts are collected and presented in appropriate formats. Also, the design variables of load per unit of projected bearing area, and bearing clearance in industrial applications, needed in the bearing design, are derived and incorporated in the design process. However, when designing a bearing for a given application, an infinite number of solutions is possible. Thus, certain limitations are imposed on the values of the bearing performance variables including stability, based on empirical guidelines. Consequently, one may select the solution for optimum conditions, say of maximum load capacity, or the minimum power loss (i.e. minimum friction). Finally, the CAD programme developed and constructed is general, fully automated, flexible, extendable, interactive and friendly to use.

M.H. Es-Saheb; Y.A. Al-Kalifa

2003-01-01T23:59:59.000Z

269

IUTAM symposium on hydrodynamic diffusion of suspended particles  

SciTech Connect (OSTI)

Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Davis, R.H. [ed.

1995-12-31T23:59:59.000Z

270

Simulation study of the effect of hydrodynamic forces on oil recovery  

E-Print Network [OSTI]

SIMULATION STUDY OF THE EFFECT OF HYDRODYNAMIC FORCES ON OIL RECOVERY A Thesis by EDUARDO ALE JANDRO IDROBO HURTADO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Petroleum Engineering SIMULATION STUDY OF THE EFFECT OF HYDRODYNAMIC FORCES ON OIL RECOVERY A Thesis by EDUARDO ALE JANDRO IDROBO HURTADO Approved as to style and content by: S, W. Poston (Chair...

Idrobo Hurtado, Eduardo Alejandro

2012-06-07T23:59:59.000Z

271

Inverse kinematics for optimal tool orientation control in 5-axis CNC machining  

Science Journals Connector (OSTI)

Abstract The problem of determining the inputs to the rotary axes of a 5-axis CNC machine is addressed, such that relative variations of orientation between the tool axis and surface normal are minimized subject to the constraint of maintaining a constant cutting speed with a ball-end tool. In the context of an orientable-spindle machine, the results of a prior study are directly applicable to the solution of this inverse-kinematics problem. However, since they are expressed in terms of the integral of the geodesic curvature, a discrete time-step solution is proposed that yields accurate rotary-axis increments at high sampling frequencies. For an orientable-table machine, a closed-form solution that specifies the rotary-axis positions as functions of the surface normal variation along the toolpath is possible. In this context, however, the feasibility of a solution is dependent upon the surface normal along the toolpath satisfying certain orientational constraints. These inverse-kinematics solutions facilitate accurate and efficient 5-axis machining of free-form surfaces without “unnecessary” actuation of the machine rotary axes.

Rida T. Farouki; Chang Yong Han; Shiqiao Li

2014-01-01T23:59:59.000Z

272

Two-Dimensional Hydrodynamic Core-Collapse Supernova Simulations with Spectral Neutrino Transport II. Models for Different Progenitor Stars  

E-Print Network [OSTI]

1D and 2D supernova simulations for stars between 11 and 25 solar masses are presented, making use of the Prometheus/Vertex neutrino-hydrodynamics code, which employs a full spectral treatment of the neutrino transport. Multi-dimensional transport aspects are treated by the ``ray-by-ray plus'' approximation described in Paper I. Our set of models includes a 2D calculation for a 15 solar mass star whose iron core is assumed to rotate rigidly with an angular frequency of 0.5 rad/s before collapse. No important differences were found depending on whether random seed perturbations for triggering convection are included already during core collapse, or whether they are imposed on a 1D collapse model shortly after bounce. Convection below the neutrinosphere sets in about 40 ms p.b. at a density above 10**12 g/cm^3 in all 2D models, and encompasses a layer of growing mass as time goes on. It leads to a more extended proto-neutron star structure with accelerated lepton number and energy loss and significantly higher muon and tau neutrino luminosities, but reduced mean energies of the radiated neutrinos, at times later than ~100 ms p.b. In case of an 11.2 solar mass star we find that low (l = 1,2) convective modes cause a probably rather weak explosion by the convectively supported neutrino-heating mechanism after ~150 ms p.b. when the 2D simulation is performed with a full 180 degree grid, whereas the same simulation with 90 degree wedge fails to explode like all other models. This sensitivity demonstrates the proximity of our 2D models to the borderline between success and failure, and stresses the need of simulations in 3D, ultimately without the axis singularity of a polar grid. (abridged)

R. Buras; H. -Th. Janka; M. Rampp; K. Kifonidis

2005-12-07T23:59:59.000Z

273

Power performance of canted blades for a vertical axis wind turbine  

Science Journals Connector (OSTI)

Small scale vertical axis wind turbines have a number of advantages for deployment in an urban environment but are subject to highly varying thrust and radial aerodynamic forces. Helical blade shapes for vertical axis wind turbines can reduce load fluctuations during turbine operation; however a helix has complicated three-dimensional geometry that can be difficult to manufacture resulting in expensive blades. A new blade configuration based on twisted straight blades that are mounted at an angle to the vertical a cant has been developed and tested in a wind tunnel in a number of different configurations and conditions. They offer the benefits of distributing the fluctuating aerodynamic loads but incorporate a linear axis so that they can be manufactured at a comparable cost to simple straight blades. The power performance data from the tunnel testing show that canted blades have comparable power output to similar straight blades and that aerodynamic fences can be used to improve power performance.

Shawn Armstrong; Stephen Tullis

2011-01-01T23:59:59.000Z

274

Atomic resolution electrostatic potential mapping of graphene sheets by off-axis electron holography  

SciTech Connect (OSTI)

Off-axis electron holography has been performed at atomic resolution with the microscope operated at 80?kV to provide electrostatic potential maps from single, double, and triple layer graphene. These electron holograms have been reconstructed in order to obtain information about atomically resolved and mean inner potentials. We propose that off-axis electron holography can now be used to measure the electrical properties in a range of two-dimensional semiconductor materials and three dimensional devices comprising stacked layers of films to provide important information about their electrical properties.

Cooper, David, E-mail: david.cooper@cea.fr [University Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054, Grenoble (France); Pan, Cheng-Ta; Haigh, Sarah [School of Materials, The University of Manchester, Manchester M13 9PL (United Kingdom)

2014-06-21T23:59:59.000Z

275

A two-dimensional matrix correction for off-axis portal dose prediction errors  

SciTech Connect (OSTI)

Purpose: This study presents a follow-up to a modified calibration procedure for portal dosimetry published by Bailey et al. ['An effective correction algorithm for off-axis portal dosimetry errors,' Med. Phys. 36, 4089-4094 (2009)]. A commercial portal dose prediction system exhibits disagreement of up to 15% (calibrated units) between measured and predicted images as off-axis distance increases. The previous modified calibration procedure accounts for these off-axis effects in most regions of the detecting surface, but is limited by the simplistic assumption of radial symmetry. Methods: We find that a two-dimensional (2D) matrix correction, applied to each calibrated image, accounts for off-axis prediction errors in all regions of the detecting surface, including those still problematic after the radial correction is performed. The correction matrix is calculated by quantitative comparison of predicted and measured images that span the entire detecting surface. The correction matrix was verified for dose-linearity, and its effectiveness was verified on a number of test fields. The 2D correction was employed to retrospectively examine 22 off-axis, asymmetric electronic-compensation breast fields, five intensity-modulated brain fields (moderate-high modulation) manipulated for far off-axis delivery, and 29 intensity-modulated clinical fields of varying complexity in the central portion of the detecting surface. Results: Employing the matrix correction to the off-axis test fields and clinical fields, predicted vs measured portal dose agreement improves by up to 15%, producing up to 10% better agreement than the radial correction in some areas of the detecting surface. Gamma evaluation analyses (3 mm, 3% global, 10% dose threshold) of predicted vs measured portal dose images demonstrate pass rate improvement of up to 75% with the matrix correction, producing pass rates that are up to 30% higher than those resulting from the radial correction technique alone. As in the 1D correction case, the 2D algorithm leaves the portal dosimetry process virtually unchanged in the central portion of the detector, and thus these correction algorithms are not needed for centrally located fields of moderate size (at least, in the case of 6 MV beam energy).Conclusion: The 2D correction improves the portal dosimetry results for those fields for which the 1D correction proves insufficient, especially in the inplane, off-axis regions of the detector. This 2D correction neglects the relatively smaller discrepancies that may be caused by backscatter from nonuniform machine components downstream from the detecting layer.

Bailey, Daniel W. [Department of Physics, State University of New York at Buffalo, Buffalo, New York 14260 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Kumaraswamy, Lalith; Bakhtiari, Mohammad [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Podgorsak, Matthew B. [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

2013-05-15T23:59:59.000Z

276

Reconstruction of the Electron Density of Molecules with Single-Axis Alignment  

SciTech Connect (OSTI)

Diffraction from the individual molecules of a molecular beam, aligned parallel to a single axis by a strong electric field or other means, has been proposed as a means of structure determination of individual molecules. As in fiber diffraction, all the information extractable is contained in a diffraction pattern from incidence of the diffracting beam normal to the molecular alignment axis. We present two methods of structure solution for this case. One is based on the iterative projection algorithms for phase retrieval applied to the coefficients of the cylindrical harmonic expansion of the molecular electron density. Another is the holographic approach utilizing presence of the strongly scattering reference atom for a specific molecule.

Starodub, Dmitri

2011-08-12T23:59:59.000Z

277

DIMENSIONAL DEPENDENCE OF THE HYDRODYNAMICS OF CORE-COLLAPSE SUPERNOVAE  

SciTech Connect (OSTI)

A major goal over the last decade has been understanding which multidimensional effects are crucial in facilitating core-collapse supernova (CCSN) explosions. Unfortunately, much of this work has necessarily assumed axisymmetry. In this work, we present analyses of simplified two-dimensional (2D) and three-dimensional (3D) CCSN models with the goal of comparing the hydrodynamics in setups that differ only in dimension. Not surprisingly, we find many differences between 2D and 3D models. While some differences are subtle and perhaps not crucial, others are dramatic and make interpreting 2D models problematic. In particular, axisymmetric models produce excess power at the largest spatial scales, power that has been deemed critical in previous explosion models. Nevertheless, our 3D models, which have an order of magnitude less power than 2D models on large scales, explode earlier. Since explosions occur earlier in 3D than in 2D, the vigorous large-scale sloshing is either not critical in any dimension or the explosion mechanism operates differently in 2D and 3D. On the other hand, we find that the average parcel of matter in the gain region has been exposed to net heating for up to 30% longer in 3D than in 2D, an effect we attribute to the differing characters of turbulence in 2D and 3D. We suggest that this effect plays a prominent role in producing earlier explosions in 3D. Finally, we discuss a simple model for the runaway growth of buoyant bubbles that is able to quantitatively account for the growth of the shock radius and predicts a critical luminosity relation.

Dolence, Joshua C.; Burrows, Adam; Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Nordhaus, Jason, E-mail: jdolence@astro.princeton.edu, E-mail: burrows@astro.princeton.edu, E-mail: jmurphy@astro.princeton.edu, E-mail: nordhaus@astro.rit.edu [Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, NY 14623 (United States)

2013-03-10T23:59:59.000Z

278

Effects of Second-Order Hydrodynamics on a Semisubmersible Floating Offshore Wind Turbine: Preprint  

SciTech Connect (OSTI)

The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of the system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the MARIN offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST in the future. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method has been applied to the OC4-DeepCwind semisubmersible platform, supporting the NREL 5-MW baseline wind turbine. The loads and response of the system due to the second-order hydrodynamics are analysed and compared to first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads and induced response data are compared to the loads and motions induced by aerodynamic loading as solved by FAST.

Bayati, I.; Jonkman, J.; Robertson, A.; Platt, A.

2014-07-01T23:59:59.000Z

279

The effects of second-order hydrodynamics on a semisubmersible floating offshore wind turbine  

Science Journals Connector (OSTI)

The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of a floating system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the Maritime Research Institute Netherlands (MARIN) offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method was applied to the Offshore Code Comparison Collaboration Continuation OC4-DeepCwind semisubmersible platform, supporting the National Renewable Energy Laboratory's 5-MW baseline wind turbine. In this paper, the loads and response of the system caused by the second-order hydrodynamics are analysed and compared to the first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads and induced response data are compared to the loads and motions induced by aerodynamic loading as solved by FAST.

I Bayati; J Jonkman; A Robertson; A Platt

2014-01-01T23:59:59.000Z

280

Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3  

E-Print Network [OSTI]

Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3 Spin wave2A Magnetic structure of NiO Neutron diffraction measurements will be performed to investigate 600K to 288K, using the Neutron Powder Diffractometer at the HFIR. Rietveld analysis of the crystal

Pennycook, Steve

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Rotation Angle for the Optimum Tracking of One-Axis Trackers  

SciTech Connect (OSTI)

An equation for the rotation angle for optimum tracking of one-axis trackers is derived along with equations giving the relationships between the rotation angle and the surface tilt and azimuth angles. These equations are useful for improved modeling of the solar radiation available to a collector with tracking constraints and for determining the appropriate motor revolutions for optimum tracking.

Marion, W. F.; Dobos, A. P.

2013-07-01T23:59:59.000Z

282

Tilt display demonstration: a display surface with multi-axis tilt & actuation  

Science Journals Connector (OSTI)

This demonstration accompanies a full paper accepted into MobileHCI '12 [1]. We demonstrate a new type of actuatable display, called a Tilt Display, that provides visual feedback combined with multi-axis tilting and vertical actuation. Its ability to ... Keywords: actuated displays, nonplanar surface interaction, physical actuation, tilt displays

Jason Alexander; Andrés Lucero; Sriram Subramanian

2012-09-01T23:59:59.000Z

283

Tilt displays: designing display surfaces with multi-axis tilting and actuation  

Science Journals Connector (OSTI)

We present a new type of actuatable display, called Tilt Displays, that provide visual feedback combined with multi-axis tilting and vertical actuation. Their ability to physically mutate provides users with an additional information channel that facilitates ... Keywords: actuated displays, non-planar surface interaction, physical actuation, tilt displays

Jason Alexander; Andrés Lucero; Sriram Subramanian

2012-09-01T23:59:59.000Z

284

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints  

E-Print Network [OSTI]

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints X. Beudaert, S name@lurpa.ens-cachan.fr Abstract A key role of the CNC is to perform the feedrate interpolation which for the next point along the path is computed. Examples and comparisons with an industrial CNC demonstrate

Paris-Sud XI, Université de

285

Journal of Vegetation Science && (2012) Salinity tolerance and the decoupling of resource axis  

E-Print Network [OSTI]

functional trade-offs are present along a gradient of low to high salinity? Location: New York State, USA and salinity gradients at three sites using principal compo- nents, correlation and fourth-corner analysesJournal of Vegetation Science && (2012) Salinity tolerance and the decoupling of resource axis

Fridley, Jason D.

286

MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy  

E-Print Network [OSTI]

Chapter 1 MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy Igor.................................................................................... 2 2. Neutron interaction with matter and scattering cross-section ........ 6 2.1 Basic scattering theory and differential cross-section................ 7 2.2 Neutron interactions and scattering lengths

Johnson, Peter D.

287

A methodology for process parameter selection in five axis laser cladding  

Science Journals Connector (OSTI)

Laser cladding industrial development is becoming an important target for high added value parts manufacturing sectors. Aeronautical or automotive industries are accomplishing great investments in order to understand the process and minimise tuning step costs now paired with. At the moment, the process is applied to three axis or 3 + 2 axis strategies, being numerous works focused on the obtainment of process parameters. All of them try to minimise the number of experimental tests necessary to optimise the great variable involving the process. These variables increase when using laser cladding on five axis kinematics in order to accomplish new targets of industrial sectors which include complex parts with complex surface to clad. The work presents a methodology which helps to choose optimal parameters for five axis laser cladding. A weighted criterion is used in order to discern between different parameters taking into account process requirements. The methodology has been used on two materials and different objectives have been established for the criterion in each one. Finally, two test parts are presented as methodology validation in industrial applications.

Iván Tabernero; Amaia Calleja; Aitzol Lamikiz; Luis Norberto López de Lacalle

2014-01-01T23:59:59.000Z

288

Hydrothermal synthesis, off-axis electron holography and magnetic properties of Fe3O4 nanoparticles  

E-Print Network [OSTI]

-sized Fe3O4 have been prepared by various methods such as sol­ gel processing, hydrothermal synthesisHydrothermal synthesis, off-axis electron holography and magnetic properties of Fe3O4 nanoparticles Jülich, Germany. Abstract. The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (

Dunin-Borkowski, Rafal E.

289

First-order design of off-axis reflective ophthalmic adaptive optics systems using afocal  

E-Print Network [OSTI]

First-order design of off-axis reflective ophthalmic adaptive optics systems using afocal for designing laser cavities, spectrographs and adaptive optics retinal imaging systems. The use, range respectively. This is discussed using examples from adaptive optics retinal imaging systems. The performance

290

Microstructure dependence of the c-axis critical current density in second-generation YBCO tapes.  

SciTech Connect (OSTI)

C-axis current flow in high temperature superconductor (HTS) tape-shaped wires arises in configurations where the local wire axis is not perpendicular to the local magnetic field, such as in power cables with helically wound HTS tapes. The c-axis critical current density J{sub c}{sup c} has been recently found to be orders of magnitude lower than the ab-plane critical current density J{sub c}{sup ab}. Here we report on J{sub c}{sup c} (77 K, sf) values of various YBa{sub 2}Cu{sub 3}O{sub 7}-based (YBCO) tapes with different microstructures. Our results show that the value of J{sub c}{sup c} (77 K, sf) decreases significantly with increasing concentration of ab-plane stacking faults in YBCO thin films and that the critical current anisotropy {gamma} = J{sub c}{sup ab}/J{sub c}{sup c} can reach values as high as 2070, implying that in the highest-anisotropy tape, {approx}20% of the tape width carries c-axis current in a helically wound power cable.

Jia, Y.; Welp, U.; Crabtree, G. W.; Kwok, W. K.; Malozemoff, A. P.; Rupich, M. W.; Fleshler, S.; Clem, J. R. (Materials Science Division); (American Superconductor Corp.); (Ames Lab.); (Iowa State Univ.)

2011-10-01T23:59:59.000Z

291

Origin of a magnetic easy axis in pipeline steel L. Clapham,a)  

E-Print Network [OSTI]

Origin of a magnetic easy axis in pipeline steel L. Clapham,a) C. Heald, T. Krause, and D. L December 1998; accepted for publication 27 April 1999 Oil and gas pipelines are generally magnetically overlooked, the magnetic properties of oil and gas pipelines are an important consideration since the most

Clapham, Lynann

292

On the probability of major-axis precession in triaxial ellipsoidal potentials  

E-Print Network [OSTI]

Orbits in triaxial ellipsoidal potentials precess about either the major or minor axis of the ellipsoid. In standard perturbation theory it can be shown that a circular orbit will precess about the minor axis if its angular momentum vector lies in a region bounded by two great circles which pass through the intermediate axis and which are inclined with minimum separation $i_T$ from the minor axis. We test the accuracy of the standard formula for $i_T$ by performing orbit integrations to determine $i_S$, the simulated turnover angle corresponding to $i_T$. We reach two principal conclusions: (i) $i_S$ is usually greater than $i_T$, by as much as 12 degrees even for moderate triaxialities, $A/1.2

P. A. Thomas; S. Vine; F. R. Pearce

1993-08-09T23:59:59.000Z

293

Multi-Fidelity Uncertainty Quantification: Application to a Vertical Axis Wind Turbine Under an  

E-Print Network [OSTI]

. Introduction Quantifying the response of a wind turbine to an extreme wind gust is an important designMulti-Fidelity Uncertainty Quantification: Application to a Vertical Axis Wind Turbine Under an Extreme Gust A. Santiago Padr´on , Juan J. Alonso and Francisco Palacios Stanford University, Stanford, CA

Alonso, Juan J.

294

Multi-Body Unsteady Aerodynamics in 2D Applied to aVertical-Axis Wind Turbine Using a Vortex Method.  

E-Print Network [OSTI]

?? Vertical axis wind turbines (VAWT) have many advantages over traditional Horizontalaxis wind turbines (HAWT).One of the more severe problem of VAWTs are the complicated… (more)

Österberg, David

2010-01-01T23:59:59.000Z

295

Development of Fully Coupled Aeroelastic and Hydrodynamic Models for Offshore Wind Turbines: Preprint  

SciTech Connect (OSTI)

Aeroelastic simulation tools are routinely used to design and analyze onshore wind turbines, in order to obtain cost effective machines that achieve favorable performance while maintaining structural integrity. These tools employ sophisticated models of wind-inflow; aerodynamic, gravitational, and inertial loading of the rotor, nacelle, and tower; elastic effects within and between components; and mechanical actuation and electrical responses of the generator and of control and protection systems. For offshore wind turbines, additional models of the hydrodynamic loading in regular and irregular seas, the dynamic coupling between the support platform motions and wind turbine motions, and the dynamic characterization of mooring systems for compliant floating platforms are also important. Hydrodynamic loading includes contributions from hydrostatics, wave radiation, and wave scattering, including free surface memory effects. The integration of all of these models into comprehensive simulation tools, capable of modeling the fully coupled aeroelastic and hydrodynamic responses of floating offshore wind turbines, is presented.

Jonkman, J. M.; Sclavounos, P. D.

2006-01-01T23:59:59.000Z

296

Hydrodynamic effects on Mission Canyon (Mississippian) oil accumulations, Billings Nose area, North Dakota  

SciTech Connect (OSTI)

Mission Canyon oil production on the south flank of the Williston basin provides an example of an area in the mature stage of exploration that shows significant hydrodynamic effects on oil accumulations related to stratigraphic traps. The effects are illustrated by the Billings Nose fields and the Elkhorn Ranch field. The reservoirs have low hydraulic gradients of about 2 m/km (10 ft/mi), tilted oil-water contacts with gradients of 5 m/km (25 ft/mi), and variable formation-water salinities that range from brackish to highly saline. Oil accumulations in some zones are displayed off structure and downdip to the northeast, parallel to porosity pinch-outs. Other zones are pure hydrodynamic closure. Future success in exploration and development in the play will depend on recognizing the hydrodynamic effects and predicting oil displacement. 34 refs., 15 figs., 1 tab.

Berg, R.R. (Texas A M Univ., College Station, TX (United States)); DeMis, W.D. (Marathon Oil Co., Houston, TX (United States)); Mitsdarffer, A.R. (Dupont Environmental Remediation Services, Houston, TX (United States))

1994-04-01T23:59:59.000Z

297

Hydrodynamics-based floating wind turbine support platform optimization: A basis function approach  

Science Journals Connector (OSTI)

Abstract The floating wind turbine support structure design problem is complicated by conflicting technical objectives and innumerable platform geometry options. Previous support structure optimization studies have been limited in their ability to evaluate the full design space due to their adherence to certain assumptions about the physical platform configuration. The present work is an effort toward developing an alternative form of the support platform optimization problem – one that abstracts details of the platform geometry and deals instead with hydrodynamic performance coefficients – in order to provide a more complete and intuitive exploration of the design space. A basis function approach, which represents the design space by linearly combining the hydrodynamic performance coefficients of a diverse set of basis platform geometries, was taken as the most straightforward way of physically constraining the platform hydrodynamic performance. Candidate designs are evaluated in the frequency domain using linearized coefficients for the wind turbine, platform, and mooring system dynamics. The platform hydrodynamic coefficients are calculated according to linear hydrodynamic theory. The optimization objective is to minimize the nacelle acceleration under several operating conditions. Optimization results for a slack catenary mooring system indicate the benefits of combining submerged volume with a widely dispersed water plane area. Results for a tension leg mooring system are consistent with conventional TLP designs. The intent is to use these results as starting points for more traditional platform parameter optimization. Examination of the possible physical interpretations of linearly combining basis platform coefficients reveals that certain aspects of this approach may have poor physicality. This points to the need to expand this first attempt with more sophisticated ways of representing the constrained hydrodynamic performance variables.

Matthew Hall; Brad Buckham; Curran Crawford

2014-01-01T23:59:59.000Z

298

4056 IEEE SENSORS JOURNAL, VOL. 13, NO. 10, OCTOBER 2013 Design and Characterization of a Soft Multi-Axis  

E-Print Network [OSTI]

4056 IEEE SENSORS JOURNAL, VOL. 13, NO. 10, OCTOBER 2013 Design and Characterization of a Soft Multi-Axis Force Sensor Using Embedded Microfluidic Channels Daniel M. Vogt, Member, IEEE, Yong-Lae Park system. We describe the design, fabrication, and characterization of a novel soft multi-axis force sensor

Park, Yong-Lae

299

Dielectric and ferroelectric properties of c-axis oriented strontium bismuth tantalate thin films applied transverse electric fields  

E-Print Network [OSTI]

Dielectric and ferroelectric properties of c-axis oriented strontium bismuth tantalate thin films and ferroelectric properties of c-axis oriented epitaxial strontium bismuth tantalate SBT thin films were American Institute of Physics. DOI: 10.1063/1.2205351 I. INTRODUCTION Strontium bismuth tantalate SBT has

Tonouchi, Masayoshi

300

Hydrodynamic Stability Analysis of Burning Bubbles in Electroweak Theory and in QCD  

E-Print Network [OSTI]

Assuming that the electroweak and QCD phase transitions are first order, upon supercooling, bubbles of the new phase appear. These bubbles grow to macroscopic sizes compared to the natural scales associated with the Compton wavelengths of particle excitations. They propagate by burning the old phase into the new phase at the surface of the bubble. We study the hydrodynamic stability of the burning and find that for the velocities of interest for cosmology in the electroweak phase transition, the shape of the bubble wall is stable under hydrodynamic perturbations. Bubbles formed in the cosmological QCD phase transition are found to be a borderline case between stability and instability.

P. Huet; K. Kajantie; R. G. Leigh; B. -H. Liu; L. McLerran

1992-12-05T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Page not found | Department of Energy  

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

21 - 9630 of 31,917 results. 21 - 9630 of 31,917 results. Download EIS-0343: Draft Environmental Impact Statement COB Energy Facility http://energy.gov/nepa/downloads/eis-0343-draft-environmental-impact-statement Download EIS-0228: Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility http://energy.gov/nepa/downloads/eis-0228-record-decision Download EIS-0183: Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility http://energy.gov/nepa/downloads/eis-0183-record-decision-3 Download EA-1696: Final Environmental Assessment Pantex Renewable Energy Project http://energy.gov/nepa/downloads/ea-1696-final-environmental-assessment Download Consortium Template (Expenditure-Based) http://energy.gov/management/downloads/consortium-template-expenditure-based Download Keystone: Proposed Penalty (2013-CE-2601)

302

ANL/APS/TB-32 Test of Horizontal Field Measurements Using Two-Axis Hall  

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

2 2 Test of Horizontal Field Measurements Using Two-Axis Hall Probes at the APS Magnetic Measurement Facility I. Vasserman Advanced Photon Source Argonne National Laboratory Argonne, IL 60439 1. Introduction The free-electron laser (FEL) project at the Advanced Photon Source (APS) will use a 400-MeV particle beam from the APS linac with RMS beam transverse size of 100 µm and requires very high performance of the insertion devices in order to achieve high intensity radiation. Averaged over period, the trajectory must deviate from the ideal on-axis trajectory by not more than 10% of the RMS beam size. Meaning that the second field integral should be straight within ±1300 G-cm 2 over the length of the device for both horizontal and vertical directions for the 400-MeV particle

303

Easy axis alignment of chemically partially ordered FePt nanoparticles  

SciTech Connect (OSTI)

Partially ordered Fe{sub 53}Pt{sub 47} nanoparticles with size around 8 nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. X-ray diffraction measurements reveal that as-made FePt particles were partially transformed into the ordered L1{sub 0} phase with some weak superlattice peaks. The room-temperature hysteresis loop and remanence curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the partially ordered FePt nanoparticles with a polyvinylchloride polymer binder, the particles could be re-dispersed in cyclohexanone. Furthermore, the easy axis of the particles coated with the polyvinylchloride polymer binder could be aligned under an external field. Easy axis alignment was confirmed from both alternating gradient magnetometer and x-ray diffraction measurements.

Kang, Shishou; Jia Zhiyong; Shi, Shifan; Nikles, David E.; Harrell, J.W. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487-0209 (United States)

2005-02-07T23:59:59.000Z

304

Axi-symmetrical flow reactor for [sup 196]Hg photochemical enrichment  

DOE Patents [OSTI]

The present invention is directed to an improved photochemical reactor useful for the isotopic enrichment of a predetermined isotope of mercury, especially, [sup 196]Hg. Specifically, two axi-symmetrical flow reactors were constructed according to the teachings of the present invention. These reactors improve the mixing of the reactants during the photochemical enrichment process, affording higher yields of the desired [sup 196]Hg product. Measurements of the variation of yield (Y) and enrichment factor (E) along the flow axis of these reactors indicates very substantial improvement in process uniformity compared to previously used photochemical reactor systems. In one preferred embodiment of the present invention, the photoreactor system was built such that the reactor chamber was removable from the system without disturbing the location of either the photochemical lamp or the filter employed therewith. 10 figures.

Grossman, M.W.

1991-04-30T23:59:59.000Z

305

Lattice Boltzmann method for heat diffusion in axis-symmetric geometries  

Science Journals Connector (OSTI)

Lattice Boltzmann Methods (LBM) have been used to solve momentum, heat and mass transport equations mainly in Cartesian coordinate system. In the present work, the LBM is extended to solve transports in axis-symmetric geometries, such as pipes and spheres. Heat diffusion and conduction in solids without and with heat generation were tested. The heat diffusion equation for axis-symmetric problem is reduced to diffusion equation as in Cartesian coordinate with an extra term due to the surface area variation along the radial direction. The extra term is treated as a source term (forcing term) in LBM. The extra term can be approximated by using finite difference or more accurately as a flux term. The results predicted by LBM are well compared with analytical solutions and finite volume method.

A.A. Mohamad

2009-01-01T23:59:59.000Z

306

Virtual machining considering dimensional, geometrical and tool deflection errors in three-axis CNC milling machines  

Science Journals Connector (OSTI)

Abstract Virtual manufacturing systems can provide useful means for products to be manufactured without the need of physical testing on the shop floor. As a result, the time and cost of part production can be decreased. There are different error sources in machine tools such as tool deflection, geometrical deviations of moving axis and thermal distortions of machine tool structures. Some of these errors can be decreased by controlling the machining process and environmental parameters. However other errors like tool deflection and geometrical errors which have a big portion of the total error, need more attention. This paper presents a virtual machining system in order to enforce dimensional, geometrical and tool deflection errors in three-axis milling operations. The system receives 21 dimensional and geometrical errors of a machine tool and machining codes of a specific part as input. The output of the system is the modified codes which will produce actual machined part in the virtual environment.

Mohsen Soori; Behrooz Arezoo; Mohsen Habibi

2014-01-01T23:59:59.000Z

307

An Einstein-Hilbert Action for Axi-Dilaton Gravity in 4-Dimensions  

E-Print Network [OSTI]

We examine the axi-dilatonic sector of low energy string theory and demonstrate how the gravitational interactions involving the axion and dilaton fields may be derived from a geometrical action principle involving the curvature scalar associated with a non-Riemannian connection. In this geometry the antisymmetric tensor 3-form field determines the torsion of the connection on the frame bundle while the gradient of the metric is determined by the dilaton field. By expressing the theory in terms of the Levi-Civita connection associated with the metric in the ``Einstein frame'' we confirm that the field equations derived from the non-Riemannian Einstein-Hilbert action coincide with the axi-dilaton sector of the low energy effective action derived from string theory.

T Dereli; Robin W Tucker

1995-02-08T23:59:59.000Z

308

High efficiency off-axis current drive by high frequency fast waves  

SciTech Connect (OSTI)

Modeling work shows that current drive can be done off-axis with high efficiency, as required for FNSF and DEMO, by using very high harmonic fast waves (“helicons” or “whistlers”). The modeling indicates that plasmas with high electron beta are needed in order for the current drive to take place off-axis, making DIII-D a highly suitable test vehicle for this process. The calculations show that the driven current is not very sensitive to the launched value of n{sub ?}, a result that can be understood from examination of the evolution of n{sub ?} as the waves propagate in the plasma. Because of this insensitivity, relatively large values (?3) of n{sub ?} can be launched, thereby avoiding some of the problems with mode conversion in the boundary found in some previous experiments. Use of a traveling wave antenna provides a very narrow n{sub ?} spectrum, which also helps avoid mode conversion.

Prater, R.; Pinsker, R. I.; Moeller, C. P. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States); Porkolab, M.; Vdovin, V. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)

2014-02-12T23:59:59.000Z

309

Contour Charts of SOFAR Speed and Axis Depth in the Pacific Ocean  

Science Journals Connector (OSTI)

Sound speeds calculated from the physical properties of sea water as measured at hydrographic stations were used to construct contour charts of SOFAR?speed and SOFAR?axis depth for the Pacific Ocean. Wilson's formula was used for the calculation of speed. Data were averaged for 1° squares plotted and smooth contours were drawn manually. Speeds averaged along great?circle paths are compared with those measured for explosions. The charts show steep gradients along the Antarctic convergence and at the convergence of the Oyashio and Kuroshio extension. The region of highest speed as well as greatest axis depth was that extending eastward from Australia to about the 150°W. The charts are used in a program for calculating source coordinates of earthquakeT phases.

Rockne H. Johnson; Roger A. Norris

1967-01-01T23:59:59.000Z

310

Tracking formulas and strategies for a receiver oriented dual-axis tracking toroidal heliostat  

SciTech Connect (OSTI)

A 4 m x 4 m toroidal heliostat with receiver oriented dual-axis tracking, also called spinning-elevation tracking, was developed as an auxiliary heat source for a hydrogen production system. A series of spinning-elevation tracking formulas have been derived for this heliostat. This included basic tracking formulas, a formula for the elevation angle for heliostat with a mirror-pivot offset, and a more general formula for the biased elevation angle. This paper presents the new tracking formulas in detail and analyzes the accuracy of applying a simplifying approximation. The numerical results show these receiver oriented dual-axis tracking formula approximations are accurate to within 2.5 x 10{sup -6} m in image plane. Some practical tracking strategies are discussed briefly. Solar images from the toroidal heliostat at selected times are also presented. (author)

Guo, Minghuan; Wang, Zhifeng; Liang, Wenfeng; Zhang, Xiliang; Zang, Chuncheng [Key Laboratory of Solar Thermal Energy and Photovoltaic System of Chinese Academy of Sciences, Institute of Electrical Engineering, Beijing 100190 (China); Lu, Zhenwu; Wei, Xiudong [Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CAS), Jilin 130033 (China)

2010-06-15T23:59:59.000Z

311

Floating axis wind turbines for offshore power generation—a conceptual study  

Science Journals Connector (OSTI)

The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

Hiromichi Akimoto; Kenji Tanaka; Kiyoshi Uzawa

2011-01-01T23:59:59.000Z

312

VOLUME 35, NUMBER 14 PHYSICAL REVIEW LETTERS 6 OCTOBER 1975 Relativistic Hydrodynamic Theory of Heavy-Ion Collisions*  

E-Print Network [OSTI]

waves and other aspects of a high-energy nuclear hydrodynamic model. ' ' Some experimental data that a conventional nuclear hydrodynamic model should be valid only when the bombarding energy per nucleon is less, Los Alamos Scientific Laboratory, University of California, Los Atamos, New Mexico 87544 (Received 11

Bertsch George F.

313

The experimental and theoretical investigaton of a horizontal-axis wind turbine  

E-Print Network [OSTI]

. Chevalier An experimental and theoretical investigation of a horizontal-axis wind energy conversion device utilizing straight blades as the force- producing surfaces was conducted. The blades were mounted horizontally between two rotating discs and were... positioned with a mechanical cern system to produce the maximum torque at every point around the revolution. The wind turbine was tested in a 7 x 10 ft low speed wind tunnel. The device converted over 20 percent of the energy available in the wind...

Milburn, Robert Terrance

2012-06-07T23:59:59.000Z

314

Method and apparatus for maintaining equilibrium in a helical axis stellarator  

DOE Patents [OSTI]

Apparatus for maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellarator includes a resonant coil system, having a configuration such that current therethrough generates a magnetic field cancelling the resonant magnetic field produced by currents driven by the plasma pressure on any given flux surface resonating with the rotational transform of another flux surface in the plasma. Current through the resonant coil system is adjusted as a function of plasma beta.

Reiman, A.; Boozer, A.

1984-10-31T23:59:59.000Z

315

Method and apparatus for maintaining equilibrium in a helical axis stellarator  

DOE Patents [OSTI]

Apparatus for maintaining three-dimensional MHD equilibrium in a plasma contained in a helical axis stellerator includes a resonant coil system, having a configuration such that current therethrough generates a magnetic field cancelling the resonant magnetic field produced by currents driven by the plasma pressure on any given flux surface resonating with the rotational transform of another flux surface in the plasma. Current through the resonant coil system is adjusted as a function of plasma beta.

Reiman, Allan (Princeton, NJ); Boozer, Allen (Rocky Hill, NJ)

1987-01-01T23:59:59.000Z

316

How DARHT Works - the World's Most Powerful X-ray Machine  

ScienceCinema (OSTI)

The Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory is an essential scientific tool that supports Stockpile Stewardship at the Laboratory. The World's most powerful x-ray machine, it's used to take high-speed images of mock nuclear devices - data that is used to confirm and modify advanced computer codes in assuring the safety, security, and effectiveness of the U.S. nuclear deterrent.

None

2014-06-25T23:59:59.000Z

317

Laboratory measurement of hydrodynamic saline dispersion within a micro-fracture network induced in granite  

E-Print Network [OSTI]

Laboratory measurement of hydrodynamic saline dispersion within a micro-fracture network induced plug of Ailsa Craig micro-granite by thermal stressing, to produce an isotropic network of fractures number­dispersion relationship for the micro-fracture network is very similar to that predicted for other

318

Hydrodynamic simulations of the colliding winds in Iota Orionis Julian M. Pittard*  

E-Print Network [OSTI]

Hydrodynamic simulations of the colliding winds in Iota Orionis Julian M. Pittard* School simulations of the colliding winds in the eccentric binary Iota Orionis (HR 1889; HD 37043) have been conducted. With the inclusion of radiative driving, the realistic simulation of such a system becomes

Pittard, Julian

319

Continuous flow multi-stage microfluidic reactors via hydrodynamic microparticle railing{  

E-Print Network [OSTI]

Continuous flow multi-stage microfluidic reactors via hydrodynamic microparticle railing{ Ryan D-at-a-time). Microfluidic processors that enable multi-stage fluidic reactions with suspended microparticles (e-on-a-chip technologies. Here we present a single-layer microfluidic reactor that utilizes a microfluidic railing

Lin, Liwei

320

Hydrodynamics studies of direct-drive cone-in-shell, fast-ignitor targets on OMEGA  

E-Print Network [OSTI]

with high efficiency up to 50% has been reported7 that heat the compressed fuel, significantly easing and the compressed core and found an energy-transfer efficiency of 20­30% Refs. 5 and 6 . Hydrodynamics experiments.1,2,5 A few experiments have been performed to assess the potential of the reentrant cone concept

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Early thermalization, hydrodynamics and energy loss in AdS/CFT  

E-Print Network [OSTI]

Gauge/gravity duality has provided unprecedented opportunities to study dynamics in certain strongly coupled gauge theories. This review aims to highlight several applications to heavy ion collisions including far-from-equilibrium dynamics, hydrodynamics and jet energy loss at strong coupling.

Chesler, Paul M

2015-01-01T23:59:59.000Z

322

Viscosity of Bacterial Suspensions: Hydrodynamic Interactions and Self-Induced Noise Shawn D. Ryan,1, 2  

E-Print Network [OSTI]

Viscosity of Bacterial Suspensions: Hydrodynamic Interactions and Self-Induced Noise Shawn D. Ryan, 2011) The viscosity of a suspension of swimming bacteria is investigated analytically and numerically fluid, result in a dramatic reduction of the effective viscosity. In agreement with experiments

Berlyand, Leonid

323

CRASH: A BLOCK-ADAPTIVE-MESH CODE FOR RADIATIVE SHOCK HYDRODYNAMICS-IMPLEMENTATION AND VERIFICATION  

SciTech Connect (OSTI)

We describe the Center for Radiative Shock Hydrodynamics (CRASH) code, a block-adaptive-mesh code for multi-material radiation hydrodynamics. The implementation solves the radiation diffusion model with a gray or multi-group method and uses a flux-limited diffusion approximation to recover the free-streaming limit. Electrons and ions are allowed to have different temperatures and we include flux-limited electron heat conduction. The radiation hydrodynamic equations are solved in the Eulerian frame by means of a conservative finite-volume discretization in either one-, two-, or three-dimensional slab geometry or in two-dimensional cylindrical symmetry. An operator-split method is used to solve these equations in three substeps: (1) an explicit step of a shock-capturing hydrodynamic solver; (2) a linear advection of the radiation in frequency-logarithm space; and (3) an implicit solution of the stiff radiation diffusion, heat conduction, and energy exchange. We present a suite of verification test problems to demonstrate the accuracy and performance of the algorithms. The applications are for astrophysics and laboratory astrophysics. The CRASH code is an extension of the Block-Adaptive Tree Solarwind Roe Upwind Scheme (BATS-R-US) code with a new radiation transfer and heat conduction library and equation-of-state and multi-group opacity solvers. Both CRASH and BATS-R-US are part of the publicly available Space Weather Modeling Framework.

Van der Holst, B.; Toth, G.; Sokolov, I. V.; Myra, E. S.; Fryxell, B.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Powell, K. G. [Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Holloway, J. P. [Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Stout, Q. [Computer Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Adams, M. L.; Morel, J. E. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States); Karni, S. [Department of Mathematics, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-06-01T23:59:59.000Z

324

NEUTRON IZATI ON, LEPTON ESCAPE,AND STELLAR HYDRODYNAMICS* W. David Arnett  

E-Print Network [OSTI]

NEUTRON IZATI ON, LEPTON ESCAPE,AND STELLAR HYDRODYNAMICS* W. David Arnett Enrico Fermi Institute University of Chicago 1. The Process of Neutronization.-Aftersili- con burning stellar matter has roughly equal numbers of neutrons and protons. Because neutron-star matter has a large excess of neutrons

Boyer, Edmond

325

Generalized dynamical density functional theory for classical fluids and the significance of inertia and hydrodynamic interactions  

E-Print Network [OSTI]

We study the dynamics of a colloidal fluid including inertia and hydrodynamic interactions, two effects which strongly influence the non-equilibrium properties of the system. We derive a general dynamical density functional theory (DDFT) which shows very good agreement with full Langevin dynamics. In suitable limits, we recover existing DDFTs and a Navier-Stokes-like equation with additional non-local terms.

Benjamin D. Goddard; Andreas Nold; Nikos Savva; Grigorios A. Pavliotis; Serafim Kalliadasis

2012-08-08T23:59:59.000Z

326

Efficient simulation of non-crossing fibers and chains in a hydrodynamic solvent  

E-Print Network [OSTI]

An efficient simulation method is presented for Brownian fiber suspensions, which includes both uncrossability of the fibers and hydrodynamic interactions between the fibers mediated by a mesoscopic solvent. To conserve hydrodynamics, collisions between the fibers are treated such that momentum and energy are conserved locally. The choice of simulation parameters is rationalised on the basis of dimensionless numbers expressing the relative strength of different physical processes. The method is applied to suspensions of semiflexible fibers with a contour length equal to the persistence length, and a mesh size to contour length ratio ranging from 0.055 to 0.32. For such fibers the effects of hydrodynamic interactions are observable, but relatively small. The non-crossing constraint, on the other hand, is very important and leads to hindered displacements of the fibers, with an effective tube diameter in agreement with recent theoretical predictions. The simulation technique opens the way to study the effect of viscous effects and hydrodynamic interactions in microrheology experiments where the response of an actively driven probe bead in a fiber suspension is measured.

J. T. Padding

2009-02-24T23:59:59.000Z

327

Hydrodynamic Modeling Analysis of Union Slough Restoration Project in Snohomish River, Washington  

SciTech Connect (OSTI)

A modeling study was conducted to evaluate additional project design scenarios at the Union Slough restoration/mitigation site during low tide and to provide recommendations for finish-grade elevations to achieve desired drainage. This was accomplished using the Snohomish River hydrodynamic model developed previously by PNNL.

Yang, Zhaoqing; Wang, Taiping

2010-12-20T23:59:59.000Z

328

ASPECTS OF SENSORY CUES AND PROPULSION IN MARINE ZOOPLANKTON HYDRODYNAMIC DISTURBANCES  

E-Print Network [OSTI]

ASPECTS OF SENSORY CUES AND PROPULSION IN MARINE ZOOPLANKTON HYDRODYNAMIC DISTURBANCES A Thesis Institute of Technology December 2009 #12;ASPECTS OF SENSORY CUES AND PROPULSION IN MARINE ZOOPLANKTON Peterson and his colleagues at the Hatfield Marine Station for collection and care of the Euphausia

329

Hydrodynamic analysis of AUV underwater docking with a cone-shaped dock under ocean currents  

Science Journals Connector (OSTI)

Abstract This paper investigates the hydrodynamics issues that are associated with \\{AUVs\\} (autonomous underwater vehicles) as they approach a cone-shaped dock, which is proposed by most AUV docking systems for the AUV?s protection and simplification. However, this docking system is more sensitive to the hydrodynamic interactions between the dock and the ocean currents. The purpose is to exploit the hydrodynamic susceptibility in AUV docking with the dock and to identify a probable design for AUV control during docking. To achieve this purpose, numerical simulations of an AUV docking with a dock are conducted based on the dynamic mesh method. This paper illustrates the numerical methodology for AUV docking simulation. To increase the accuracy of the numerical simulation, turbulence models and grid-dependence problems are first studied. Then, 3D (three-dimensional) numerical simulations show the dependence of the AUV fluid forces near the dock on various velocities, accelerations, dock shapes, gliding modes, cross currents from several directions and rudder angles. The hydrodynamic behaviors of an AUV docking with a dock are obtained, which provide helpful suggestions for successful docking.

Lihong Wu; Yiping Li; Shaojuan Su; Peng Yan; Yu Qin

2014-01-01T23:59:59.000Z

330

HYDRODYNAMIC LIMITS FOR KINETIC EQUATIONS AND THE DIFFUSIVE APPROXIMATION OF RADIATIVE  

E-Print Network [OSTI]

HYDRODYNAMIC LIMITS FOR KINETIC EQUATIONS AND THE DIFFUSIVE APPROXIMATION OF RADIATIVE TRANSPORT . The radiative transport equations, satisfied by the Wigner function for random acoustic waves, present#usive approximation of the radiative transport equation. 1. Introduction We consider a class of kinetic models

Tzavaras, Athanasios E.

331

HYDRODYNAMIC LIMITS FOR KINETIC EQUATIONS AND THE DIFFUSIVE APPROXIMATION OF RADIATIVE  

E-Print Network [OSTI]

HYDRODYNAMIC LIMITS FOR KINETIC EQUATIONS AND THE DIFFUSIVE APPROXIMATION OF RADIATIVE TRANSPORT of the radiative transport equation. 1. Introduction We consider a class of kinetic models equipped with a single. A general compactness frame- work is obtained for the diffusive scaling in L1 . The radiative transport

Tzavaras, Athanasios E.

332

Energy Conversion Efficiency of Nanofluidic Batteries: Hydrodynamic Slip and Access Resistance  

E-Print Network [OSTI]

Energy Conversion Efficiency of Nanofluidic Batteries: Hydrodynamic Slip and Access Resistance Yu and concentration polarization) on the energy conversion efficiency of pressure-driven electrolyte flow through battery system is its low energy conversion efficiency. Up to now, the energy conversion efficiencies have

Chang, Hsueh-Chia

333

Symposium on Naval Hydrodynamics Gothenburg, Sweden, 26-31 August 2012  

E-Print Network [OSTI]

29th Symposium on Naval Hydrodynamics Gothenburg, Sweden, 26-31 August 2012 High will be dramatically different from current mainstream supercomputers in terms of computing power and parallel are demonstrated for plunging breaking waves behind a bump using 2.2 billion grid points running on thousands

Yang, Jianming

334

Quenching massive galaxies with on-the-fly feedback in cosmological hydrodynamic simulations  

Science Journals Connector (OSTI)

......tracking the dynamics of gas inflows and outflows directly...at large computational cost. Although hydrodynamic...mergers and yield hot gas in massive haloes, they...low masses in the hot-gas-quenching case may partly...shows the energy density production rate of quenching as a......

J. M. Gabor; R. Davé; B. D. Oppenheimer; K. Finlator

2011-11-11T23:59:59.000Z

335

Implosion hydrodynamics of fast ignition targetsa... R. B. Stephens,1,b  

E-Print Network [OSTI]

. In the initial concept2 the ignition pulse is provided by an ultrahigh-intensity laser that bores into the lowerImplosion hydrodynamics of fast ignition targetsa... R. B. Stephens,1,b S. P. Hatchett,2 M. Tabak,2 National Laboratory, Livermore, California 94550 3 Laboratory for Laser Energetics, University of Rochester

336

Hydrodynamic and water quality river basin modeling using CE-QUAL-W2 version 3  

E-Print Network [OSTI]

-dimensional (longitudinal-vertical) water quality and hydrodynamic computer simulation model that was originally developed of the Lower Snake River in the Northwestern USA; the Bull Run River basin composed of 3 water supply and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality

Wells, Scott A.

337

Comparing galactic satellite properties in hydrodynamical and N-body simulations  

Science Journals Connector (OSTI)

......These high-resolution runs are 83 times more resolved...207/202 102/110 To run the DM only counterparts...intimately related with gasoline which is its hydrodynamical...algorithms), allowing a straight, direct comparison of...those used for the hydro runs; we simply transform......

Jascha A. Schewtschenko; Andrea V. Macciò

2011-05-11T23:59:59.000Z

338

Hydrodynamic Coefficients and Wave Loads for a WEC Device in Heaving Mode  

E-Print Network [OSTI]

. This model is intended to be used for WEC control purposes. A semi-analytical approach is therefore proposed for the computation of the hydrodynamic coefficients and the excitation forces. The boundary value problem is solved--Wave Energy Converter, potential theory, eigen- function expansion, wave-loads, heaving mode, scattering

Paris-Sud XI, Université de

339

A pulsed power hydrodynamics approach to exploring properties of warm dense matter  

SciTech Connect (OSTI)

Pulsed Power Hydrodynamics, as an application of low-impedance, pulsed power, and high magnetic field technology developed over the last decade to study advanced hydrodynamic problems, instabilities, turbulence, and material properties, can potentially be applied to the study of the behavior and properties of warm dense matter (WDM) as well. Exploration of the properties, such as equation of state and conductivity, of warm dense matter is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to a few times solid density) and modest temperatures ({approx}1-10 eV). Warm dense matter conditions can be achieved by laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers is applying these techniques using petawatt scale laser systems, but the microscopic size scale of the WDM produced in this way limits access to some physics phenomena. Pulsed power hydrodynamics techniques, either through high convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques both offer the prospect for producing warm dense matter in macroscopic quantities. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. Similarly, liner compression of normal density material, perhaps using multiple reflected shocks can provide access to the challenging region above normal density -- again with the requirement of very large amounts of driving energy. In this paper we will provide an introduction to techniques that might be applied to explore this interesting new application of the energy-rich technology of pulse power and high magnetic fields.

Reinovsky, Robert Emil [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

340

Hybrid Characteristics: 3D radiative transfer for parallel adaptive mesh refinement hydrodynamics  

E-Print Network [OSTI]

We have developed a three-dimensional radiative transfer method designed specifically for use with parallel adaptive mesh refinement hydrodynamics codes. This new algorithm, which we call hybrid characteristics, introduces a novel form of ray tracing that can neither be classified as long, nor as short characteristics, but which applies the underlying principles, i.e. efficient execution through interpolation and parallelizability, of both. Primary applications of the hybrid characteristics method are radiation hydrodynamics problems that take into account the effects of photoionization and heating due to point sources of radiation. The method is implemented in the hydrodynamics package FLASH. The ionization, heating, and cooling processes are modelled using the DORIC ionization package. Upon comparison with the long characteristics method, we find that our method calculates the column density with a similarly high accuracy and produces sharp and well defined shadows. We show the quality of the new algorithm in an application to the photoevaporation of multiple over-dense clumps. We present several test problems demonstrating the feasibility of our method for performing high resolution three-dimensional radiation hydrodynamics calculations that span a large range of scales. Initial performance tests show that the ray tracing part of our method takes less time to execute than other parts of the calculation (e.g. hydrodynamics and adaptive mesh refinement), and that a high degree of efficiency is obtained in parallel execution. Although the hybrid characteristics method is developed for problems involving photoionization due to point sources, the algorithm can be easily adapted to the case of more general radiation fields.

Erik-Jan Rijkhorst; Tomasz Plewa; Anshu Dubey; Garrelt Mellema

2005-05-10T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Three Dimensional Numerical General Relativistic Hydrodynamics I: Formulations, Methods, and Code Tests  

E-Print Network [OSTI]

This is the first in a series of papers on the construction and validation of a three-dimensional code for general relativistic hydrodynamics, and its application to general relativistic astrophysics. This paper studies the consistency and convergence of our general relativistic hydrodynamic treatment and its coupling to the spacetime evolutions described by the full set of Einstein equations with a perfect fluid source. The numerical treatment of the general relativistic hydrodynamic equations is based on high resolution shock capturing schemes. These schemes rely on the characteristic information of the system. A spectral decomposition for general relativistic hydrodynamics suitable for a general spacetime metric is presented. Evolutions based on three different approximate Riemann solvers coupled to four different discretizations of the Einstein equations are studied and compared. The coupling between the hydrodynamics and the spacetime (the right and left hand side of the Einstein equations) is carried out in a treatment which is second order accurate in {\\it both} space and time. Convergence tests for all twelve combinations with a variety of test beds are studied, showing consistency with the differential equations and correct convergence properties. The test-beds examined include shocktubes, Friedmann-Robertson-Walker cosmology tests, evolutions of self-gravitating compact (TOV) stars, and evolutions of relativistically boosted TOV stars. Special attention is paid to the numerical evolution of strongly gravitating objects, e.g., neutron stars, in the full theory of general relativity, including a simple, yet effective treatment for the surface region of the star (where the rest mass density is abruptly dropping to zero).

J. A. Font; M. Miller; W. Suen; M. Tobias

1998-11-04T23:59:59.000Z

342

Inversion of azimuthally dependent NMO velocity in transversely isotropic media with a tilted axis of symmetry  

SciTech Connect (OSTI)

Just as the transversely isotropic model with a vertical symmetry axis (VTI media) is typical for describing horizontally layered sediments, transverse isotropy with a tilted symmetry axis (TTI) describes dipping TI layers (such as tilted shale beds near salt domes) or crack systems. P-wave kinematic signatures in TTI media are controlled by the velocity V{sub PO} in the symmetry direction, Thomsen's anisotropic coefficients {xi} and {delta}, and the orientation (tilt {nu} and azimuth {beta}) of the symmetry axis. Here, the authors show that all five parameters can be obtained from azimuthally varying P-wave NMO velocities measured for two reflectors with different dips and/or azimuths (one of the reflectors can be horizontal). The shear-wave velocity V{sub SO} in the symmetry direction, which has negligible influence on P-wave kinematic signatures, can be found only from the moveout of shear waves. Using the exact NMO equation, the authors examine the propagation of errors in observed moveout velocities into estimated values of the anisotropic parameters and establish the necessary conditions for a stable inversion procedure. Since the azimuthal variation of the NMO velocity is elliptical, each reflection event provides them with up to three constraints on the model parameters. Generally, the five parameters responsible for P-wave velocity can be obtained from two P-wave ellipses, but the feasibility of the moveout inversion strongly depends on the tilt {nu}. While most of the analysis is carried out for a single layer, the authors also extend the inversion algorithm to vertically heterogeneous TTI media above a dipping reflector using the generalized Dix equation. A synthetic example for a strongly anisotropic, stratified TTI medium demonstrates a high accuracy of the inversion.

Grechka, V.; Tsvankin, I.

2000-02-01T23:59:59.000Z

343

Measurement of the rotational transform at the axis of a tokamak  

Science Journals Connector (OSTI)

Measurements of the internal magnetic field structure of Texas Experimental Tokamak discharges are made by use of laser-induced fluorescence of an injected Li0 beam. From measurements near the magnetic axis, we obtain the axial safety factor, q0 (or equivalently the rotational transform, ?=2?/q) for various discharge conditions. In particular, for low-qa sawtoothing discharges, we find time-averaged values of q0 significantly less than 1 (?0.7 to 0.8), in contrast with models used to describe the nonlinear internal relaxation process commonly known as sawteeth.

W. P. West; D. M. Thomas; J. S. deGrassie; S. B. Zheng

1987-06-29T23:59:59.000Z

344

A Large Liquid Argon TPC for Off-axis NuMI Neutrino Physics  

SciTech Connect (OSTI)

The ICARUS collaboration has shown the power of the liquid argon time projection chamber (LArTPC) technique to image events with bubble-chamber-like quality. I will describe a proposed long-baseline {nu}e appearance experiment utilizing a large ({>=} 15 kton1) LArTPC placed off-axis of Fermilab's NuMI {nu}{mu} beam. The total LArTPC program as it presently stands, which includes a number of smaller R and D projects designed to examine the key design issues, will be outlined.

Menary, Scott [York University, Toronto (Canada)

2006-07-11T23:59:59.000Z

345

Solutions for Neutral for Axi-Dilaton Gravity in 4-Dimensions  

E-Print Network [OSTI]

We examine a 1 parameter class of actions describing the gravitational interaction between a pair of scalar fields and Einsteinian gravitation. When the parameter is positive the theory corresponds to an axi-dilatonic sector of low energy string theory. We exploit an SL(2,R) symmetry of the theory to construct a family of electromagnetically neutral solutions with non-zero axion and dilaton charge from solutions of the Brans-Dicke theory. We also comment on solutions to the theory with negative coupling parameter.

T Dereli; M Onder; Robin W Tucker

1995-02-08T23:59:59.000Z

346

Seismic reflection images of a near-axis melt sill within the lower crust at the Juan de Fuca ridge  

Science Journals Connector (OSTI)

... -axis seamounts with chemistry distinct from the axial lavas (Fig. 4a). Observations by submersible vehicles have also reported the presence of low-temperature hydrothermal venting ?3.3?km ... ratio is 0.25. Reflection coefficients

J. Pablo Canales; Mladen R. Nedimovi?; Graham M. Kent; Suzanne M. Carbotte; Robert S. Detrick

2009-07-02T23:59:59.000Z

347

Environmental and Performance Analysis of a 5kW Horizontal Axis Wind Turbine in East Central Alberta.  

E-Print Network [OSTI]

??This thesis investigates the environmental and performance results of a 5kW horizontal axis wind turbine installed in east-central Alberta. Life cycle assessment (LCA) methodology was… (more)

Rooke, Braden

2012-01-01T23:59:59.000Z

348

Multi-axis compliant mechanism-based nanopositioner for multi-mode mechanical testing of carbon nanotubes  

E-Print Network [OSTI]

This thesis documents the design of a multi-axis nanopositioner that addresses a need for carbon nanotube (CNT) instrumentation that is capable of multiple modes of mechanical testing. This nanopositioner is a solution to ...

Lin, Kevin, S.M. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

349

Simultaneous two-axis vibration measurement of a nonmetallic cylinder by electromagnetic induction and metallic foil loops  

Science Journals Connector (OSTI)

This work presents a method based on electromagnetic induction for the simultaneous non-contact measurement of two-axis lateral vibrations of a nonmetallic cylinder. The suggested method ... pair of loop is induc...

Soon Woo Han; Jin Ki Kim; Yoon Young Kim

2011-08-01T23:59:59.000Z

350

Feed rate calculation algorithm for the homogeneous material deposition of blisk blades by 5-axis laser cladding  

Science Journals Connector (OSTI)

The application of laser cladding technology is becoming widely extended in the ... parts. These complex parts require 5-axis laser cladding deposition processes whose programming demands optimized and ... homoge...

Amaia Calleja; Iván Tabernero…

2014-10-01T23:59:59.000Z

351

A six-axis robotic sample changer for high-throughput neutron powder diffraction and texture measurements  

Science Journals Connector (OSTI)

A new six-axis robotic sample changer for neutron powder diffraction experiments, including texture measurements, has enabled a novel set of experiments to be performed at the High-Pressure Preferred Orientation diffractometer at the Lujan Neutron Scattering Center.

Losko, A.S.

2014-11-18T23:59:59.000Z

352

Latitudinal gradients of coniferous tree species, vegetation, and climate in the Sierran-Cascade axis of Northern California  

Science Journals Connector (OSTI)

Latitudinal gradients of tree species composition along the Sierran/Cascade axis in northern California were explored by comparing forests of Lassen Volcanic and Yosemite National Parks, USA. A calibration pro...

Albert J. Parker

1994-12-01T23:59:59.000Z

353

The influence of the nonverticality of the azimuthal rotation axis of the concentrator (heliostat) on program tracking accuracy  

Science Journals Connector (OSTI)

It is shown that the nonverticality of the azimuthal axis has a significant influence on the accuracy of the program control of the concentrator (heliostat). To eliminate this error, it is...

A. A. Abdurakhmanov; S. A. Orlov; A. S. Saribaev; Kh. K. Fazilov

2010-12-01T23:59:59.000Z

354

Medium-solidity Vertical Axis Wind Turbines for use in Urban Environments S. Tullis, A. Fiedler, K. McLaren, S. Ziada  

E-Print Network [OSTI]

Medium-solidity Vertical Axis Wind Turbines for use in Urban Environments S. Tullis, A. Fiedler, K Vertical axis wind turbines are currently experiencing a renewed interest in small- scale applications: vertical axis wind turbines, vibration, blade aerodynamics #12;Introduction In community wind power

Tullis, Stephen

355

A generalized on-line estimation and control of five-axis contouring errors of CNC machine tools  

Science Journals Connector (OSTI)

Abstract Nonlinear and configuration-dependent five-axis kinematics make contouring errors difficult to estimate and control in real time. This paper proposes a generalized method for the on-line estimation and control of five-axis contouring errors. First, a generalized Jacobian function is derived based on screw theory in order to synchronize the motions of linear and rotary drives. The contouring error components contributed by all active drives are estimated through interpolated position commands and the generalized Jacobian function. The estimated axis components of contouring errors are fed back to the position commands of each closed loop servo drive with a proportional gain. The proposed contouring error estimation and control methods are general, and applicable to arbitrary five-axis tool paths and any kinematically admissible five-axis machine tools. The proposed algorithms are verified experimentally on a five-axis machine controlled by a modular research CNC system built in-house. The contouring errors are shown to be reduced by half with the proposed method, which is simple to implement in existing CNC systems.

Jixiang Yang; Yusuf Altintas

2015-01-01T23:59:59.000Z

356

Simulation of winds as seen by a rotating vertical axis wind turbine blade  

SciTech Connect (OSTI)

The objective of this report is to provide turbulent wind analyses relevant to the design and testing of Vertical Axis Wind Turbines (VAWT). A technique was developed for utilizing high-speed turbulence wind data from a line of seven anemometers at a single level to simulate the wind seen by a rotating VAWT blade. Twelve data cases, representing a range of wind speeds and stability classes, were selected from the large volume of data available from the Clayton, New Mexico, Vertical Plane Array (VPA) project. Simulations were run of the rotationally sampled wind speed relative to the earth, as well as the tangential and radial wind speeds, which are relative to the rotating wind turbine blade. Spectral analysis is used to compare and assess wind simulations from the different wind regimes, as well as from alternate wind measurement techniques. The variance in the wind speed at frequencies at or above the blade rotation rate is computed for all cases, and is used to quantitatively compare the VAWT simulations with Horizontal Axis Wind Turbine (HAWT) simulations. Qualitative comparisons are also made with direct wind measurements from a VAWT blade.

George, R.L.

1984-02-01T23:59:59.000Z

357

String dynamics and ejection along the axis of a spinning black hole  

Science Journals Connector (OSTI)

Relativistic current carrying strings moving axisymmetrically on the background of a Kerr black hole are studied. The boundaries and possible types of motion of a string with a given energy and current are found. Regions of parameters for which the string falls into the black hole, is trapped in a toroidal volume, or can escape to infinity, are identified, and representative trajectories are examined by numerical integration, illustrating various interesting behaviors. In particular, we find that a string can start out at rest near the equatorial plane and, after bouncing around, be ejected out along the axis, some of its internal (elastic or rotational kinetic) energy having been transformed into translational kinetic energy. The resulting velocity can be an order unity fraction of the speed of light. This process results from the presence of an outer tension barrier and an inner angular momentum barrier that are deformed by the gravitational field. We speculatively discuss the possible astrophysical significance of this mechanism as a means of launching a collimated jet of magnetohydrodynamics plasma flux tubes along the spin axis of a gravitating system fed by an accretion disk.

Ted Jacobson and Thomas P. Sotiriou

2009-03-26T23:59:59.000Z

358

Eucentric four-axis ultrahigh vacuum goniometer for reflection high-energy electron diffraction applications  

SciTech Connect (OSTI)

The design and performance of a four-axis low-profile eucentric UHV goniometer for in situ reflection high-energy electron diffraction (RHEED) studies during film deposition is reported. The design provides one translational and three rotational degrees of freedom that are fully independent. Although developed to facilitate high-pressure RHEED during the growth of oxide thin films by pulsed laser deposition, this goniometer design is applicable to other UHV techniques including molecular beam epitaxy. The goniometer requires only a single DN 100 CF flange (6 in. o.d., 100 mm i.d.), making it suitable for small deposition systems, too. Samples, attached to a resistively heated holder, can be easily transferred on and off of the goniometer without breaking vacuum. The holder accommodates samples up to 10 mmx10 mm in size and allows them to be heated to 900 deg. C in pure oxygen while being attached to the goniometer. Full eucentric motion of the hot sample is possible with a typical axis precision of <0.1 deg. Most of the mechanism is located in air, allowing the use of standard materials and lubricants, substantially reducing the in-vacuum mechanics, and increasing the precision, reliability, and robustness of the system.

Schmehl, A.; Schulz, R.R.; Mannhart, J. [Experimentalphysik VI, Elektronische Korrelationen und Magnetismus, Institut fuer Physik, Universitaet Augsburg, Universitaetsstrasse 1, D-86135 Augsburg (Germany)

2005-12-15T23:59:59.000Z

359

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. part I: Aerodynamics  

Science Journals Connector (OSTI)

Abstract The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative concepts in this context. Vertical axis wind turbines (VAWTs) are one promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess their technical feasibility. A comprehensive review detailing the areas of engineering expertise utilised in developing an understanding of the coupled dynamics of floating \\{VAWTs\\} has been developed through a series of articles. This first article details the aerodynamic modelling of VAWTs, providing a review of available models, discussing their applicability to floating \\{VAWTs\\} and current implementations by researchers in this field. A concise comparison between conventional horizontal axis wind turbines and \\{VAWTs\\} is also presented, outlining the advantages and disadvantages of these technologies for the floating wind industry. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Andrew Shires; Maurizio Collu

2014-01-01T23:59:59.000Z

360

MHK Projects/Marine Hydrodynamics Laboratory at the University of Michigan  

Open Energy Info (EERE)

Marine Hydrodynamics Laboratory at the University of Michigan Marine Hydrodynamics Laboratory at the University of Michigan < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":5,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"350px","centre":false,"title":"","label":"","icon":"File:Aquamarine-marker.png","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.2808,"lon":-83.743,"alt":0,"address":"","icon":"http:\/\/prod-http-80-800498448.us-east-1.elb.amazonaws.com\/w\/images\/7\/74\/Aquamarine-marker.png","group":"","inlineLabel":"","visitedicon":""}]}

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Viscosity of bacterial suspensions : hydrodynamic interactions and self-induced noise.  

SciTech Connect (OSTI)

The viscosity of a suspension of swimming bacteria is investigated analytically and numerically. We propose a simple model that allows for efficient computation for a large number of bacteria. Our calculations show that long-range hydrodynamic interactions, intrinsic to self-locomoting objects in a viscous fluid, result in a dramatic reduction of the effective viscosity. In agreement with experiments on suspensions of Bacillus subtilis, we show that the viscosity reduction is related to the onset of large-scale collective motion due to interactions between the swimmers. The simulations reveal that the viscosity reduction occurs only for relatively low concentrations of swimmers: Further increases of the concentration yield an increase of the viscosity. We derive an explicit asymptotic formula for the effective viscosity in terms of known physical parameters and show that hydrodynamic interactions are manifested as self-induced noise in the absence of any explicit stochasticity in the system.

Ryan, S. D.; Haines, B. M.; Berlyand, L. V.; Ziebert, F.; Aranson, I. S. (Materials Science Division); (Pennsylvania State Univ.); (UMR CNRS)

2011-05-01T23:59:59.000Z

362

Modeling the coupling of reaction kinetics and hydrodynamics in a collapsing cavity  

SciTech Connect (OSTI)

We introduce a model of cavitation based on the multiphase Lattice Boltzmann method (LBM) that allows for coupling between the hydrodynamics of a collapsing cavity and supported solute chemical species. We demonstrate that this model can also be coupled to deterministic or stochastic chemical reactions. In a two-species model of chemical reactions (with a major and a minor specie), the major difference observed between the deterministic and stochastic reactions takes the form of random fluctuations in concentration of the minor species. We demonstrate that advection associated with the hydrodynamics of a collapsing cavity leads to highly inhomogeneous concentration of solutes. In turn these inhomogeneities in concentration may lead to significant increase in concentration-dependent reaction rates and can result in a local enhancement in the production of minor species.

Mishra, Sudib [University of Arizona; Deymier, Pierre [University of Arizona; Muralidharan, Krishna [University of Arizona; Frantziskonis, G. [University of Arizona; Pannala, Sreekanth [ORNL; Simunovic, Srdjan [ORNL

2010-01-01T23:59:59.000Z

363

Second-order discretization in space and time for radiation hydrodynamics  

SciTech Connect (OSTI)

We present a method for solving the equations of radiation hydrodynamics that is second-order accurate in space and time. This method combines the MUSCL-Hancock method for solving the Euler equations with the TR/BDF2 scheme in time for solving the equations of radiative transfer. We use an LDFEM to discretize the radiative transfer equations in space, which, though uncommon for radiation diffusion calculations, is a standard for radiation transport applications. We address the challenges inherent to using different spatial discretizations for the hydrodynamics and radiation and demonstrate how these may be overcome. We define our method for a 1-D model of compressible fluid dynamics coupled with grey radiation diffusion. Using the method of manufactured solutions, we show that the method is second-order accurate in space and time for both the equilibrium diffusion and streaming limit. (authors)

Edwards, J. D.; Morel, J. E. [Department of Nuclear Engineering, TAMU 3133, Texas A and M University, College Station, TX 77843 (United States); Lowrie, R. B. [Computational Physics Group CCS-2, M.S. D413, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

364

Dilepton production from the quark-gluon plasma using (3+1)-dimensional anisotropic dissipative hydrodynamics  

E-Print Network [OSTI]

We compute dilepton production from the deconfined phase of the quark-gluon plasma using leading-order (3+1)-dimensional anisotropic hydrodynamics. The anisotropic hydrodynamics equa- tions employed describe the full spatiotemporal evolution of the transverse temperature, spheroidal momentum-space anisotropy parameter, and the associated three-dimensional collective flow of the matter. The momentum-space anisotropy is also taken into account in the computation of the dilepton production rate, allowing for a self-consistent description of dilepton production from the quark-gluon plasma. For our final results, we present predictions for high-energy dilepton yields as a function of invariant mass, transverse momentum, and pair rapidity. We demonstrate that high- energy dilepton production is extremely sensitive to the assumed level of initial momentum-space anisotropy of the quark-gluon plasma. As a result, it may be possible to experimentally constrain the early-time momentum-space anisotropy of the quark-gluon...

Ryblewski, Radoslaw

2015-01-01T23:59:59.000Z

365

Energy flow between two hydrodynamically coupled particles kept at different effective temperatures  

E-Print Network [OSTI]

We measure the energy exchanged between two hydrodynamically coupled micron-sized Brownian particles trapped in water by two optical tweezers. The system is driven out of equilibrium by random forcing the position of one of the two particles. The forced particle behaves as it has an "effective temperature" higher than that of the other bead. This driving modifies the equilibrium variances and cross-correlation functions of the bead positions: we measure an energy flow between the particles and an instantaneous cross-correlation, proportional to the effective temperature difference between the two particles. A model of the interaction which is based on classical hydrodynamic coupling tensors is proposed. The theoretical and experimental results are in excellent agreement.

Antoine Bérut; Artyom Petrosyan; Sergio Ciliberto

2015-02-06T23:59:59.000Z

366

Hydrodynamic flow in the vicinity of a nanopore induced by an applied voltage  

E-Print Network [OSTI]

Continuum simulation is employed to study ion transport and fluid flow through a nanopore in a solid-state membrane under an applied potential drop. Results show the existence of concentration polarization layers on the surfaces of the membrane. The nonuniformity of the ionic distribution gives rise to an electric pressure that drives vortical motion in the fluid. There is also a net hydrodynamic flow through the nanopore due to an asymmetry induced by the membrane surface charge. The qualitative behavior is similar to that observed in a previous study using molecular dynamic simulations. The current--voltage characteristics show some nonlinear features but are not greatly affected by the hydrodynamic flow in the parameter regime studied. In the limit of thin Debye layers, the electric resistance of the system can be characterized using an equivalent circuit with lumped parameters. Generation of vorticity can be understood qualitatively from elementary considerations of the Maxwell stresses. However, the flow...

Mao, Mao; Hu, Guohui

2013-01-01T23:59:59.000Z

367

Hydrodynamic provinces and oceanic connectivity from a transport network help designing marine reserves  

E-Print Network [OSTI]

Oceanic dispersal and connectivity have been identified as crucial factors for structuring marine populations and designing Marine Protected Areas (MPAs). Focusing on larval dispersal by ocean currents, we propose an approach coupling Lagrangian transport and new tools from Network Theory to characterize marine connectivity in the Mediterranean basin. Larvae of different pelagic durations and seasons are modeled as passive tracers advected in a simulated oceanic surface flow from which a network of connected areas is constructed. Hydrodynamical provinces extracted from this network are delimited by frontiers which match multi-scale oceanographic features. By examining the repeated occurrence of such boundaries, we identify the spatial scales and geographic structures that would control larval dispersal across the entire seascape. Based on these hydrodynamical units, we study novel connectivity metrics for existing reserves. Our results are discussed in the context of ocean biogeography and MPAs design, having...

Rossi, Vincent; López, Cristóbal; Hernández-García, Emilio

2014-01-01T23:59:59.000Z

368

Liquid contact resonance atomic force microscopy via experimental reconstruction of the hydrodynamic function  

SciTech Connect (OSTI)

We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.

Tung, Ryan C., E-mail: ryan.tung@nist.gov; Killgore, Jason P.; Hurley, Donna C. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2014-06-14T23:59:59.000Z

369

Energy flow between two hydrodynamically coupled particles kept at different effective temperatures  

E-Print Network [OSTI]

We measure the energy exchanged between two hydrodynamically coupled micron-sized Brownian particles trapped in water by two optical tweezers. The system is driven out of equilibrium by random forcing the position of one of the two particles. The forced particle behaves as it has an "effective temperature" higher than that of the other bead. This driving modifies the equilibrium variances and cross-correlation functions of the bead positions: we measure an energy flow between the particles and an instantaneous cross-correlation, proportional to the effective temperature difference between the two particles. A model of the interaction which is based on classical hydrodynamic coupling tensors is proposed. The theoretical and experimental results are in excellent agreement.

Antoine Bérut; Artyom Petrosyan; Sergio Ciliberto

2014-08-22T23:59:59.000Z

370

Laboratory Experiments and Hydrodynamic Modeling of a Bed Leveler Used to Level the Bottom of Ship Channels after Dredging  

E-Print Network [OSTI]

This study was conducted to ascertain the impacts of bed leveling, following ship channel dredging operations, and to also investigate the hydrodynamic flow field around box bed levelers. Laboratory experiments were conducted with bed levelers...

Paul, Ephraim Udo

2011-02-22T23:59:59.000Z

371

Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams  

SciTech Connect (OSTI)

Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD.

Roberts, Brian J [ORNL; Mulholland, Patrick J [ORNL; Houser, Jeffrey N [ORNL

2007-01-01T23:59:59.000Z

372

Effects of Hydrodynamic Modelling in Fully Coupled Simulations of a Semi-submersible Wind Turbine  

Science Journals Connector (OSTI)

This work examines the dynamic response of a single semi-submersible wind turbine (SSWT) based on different hydrodynamic theories. Comparisons of platform motions and structural responses in the wind turbine are shown for simulations for a model with linear potential ?ow solution and quadratic drag and simulations with only Morison-type forces. The SSWT modelled in this study is based on WindFloat and carries the NREL 5MW wind turbine and should be considered a large volume structure. This implies that diffraction effects should be considered by using potential ?ow theory and viscous effects by Morison's equation.A new coupled simulation code was developed by linking the SIMO and RIFLEX hydrodynamic, structural, and control system computational tools, from MARINTEK, with the aerodynamic forces and wind ?eld generation capabili–ties of AeroDyn and TurbSim, from NREL. In contrast to other available simulation codes, this combination enabled the implementation of these two different hydrodynamic theories and offered the possibility of ?nite element mooring line models. Wave-only simulations were considered ?rst, in order to tune and compare potential theory versus the inertia term in Morison's equation. Some limited coupled wave-wind simulations give an indication of the extent to which hydrodynamic modelling affects the global response.The SSWT case study showed that the Morison model with forces integrated up to wave elevation gave a good representation of the motions compared to the potential ?ow model with quadratic drag forces. It also showed that mo–tions are sensitive to choice of added mass coefficients, stretching and dynamic pressure under the columns. Combined wind and wave simulations, using a non-optimized control approach, showed that pitch motions in?uence the power production and blade bending moments.

Marit I. Kvittem; Erin E. Bachynski; Torgeir Moan

2012-01-01T23:59:59.000Z

373

3D Relativistic Hydrodynamic Computations Using Lattice-QCD-Inspired Equations of State  

E-Print Network [OSTI]

In this communication, we report results of three-dimensional hydrodynamic computations, by using equations of state with a critical end point as suggested by the lattice QCD. Some of the results are an increase of the multiplicity in the mid-rapidity region and a larger elliptic-flow parameter v2. We discuss also the effcts of the initial-condition fluctuations and the continuous emission.

Yogiro Hama; Rone P. G. Andrade; Frederique Grassi; Otavio Socolowski Jr; Takeshi Kodama; Bernardo Tavares; S. S. Padula

2005-10-07T23:59:59.000Z

374

Depositional environment and hydrodynamic flow in Lower Cretaceous J Sandstone, Lonetree field, Denver basin, Colorado  

E-Print Network [OSTI]

aquifer, as modified from Hoeger (1968) and Pruit (1978). 19 Diagram illustrating the trapping of oil by both capillary and hydrodynamic elements. 25 Extrapolation of the initial shutin period of the Amoco 56 C-1 UPRR, T4S-R59W, illustrating the rela... buildup curve for the initial shutin (ISI) period of the Miami Oil 1 Lea sure well showing the extrapolated original pressure (Po). . . . . . . . . . . . . . . . Pressure buildup curve for the initial shutin (ISI) period of the Huckabay 1 Amoco Maddern...

Bicknell, James Scott

1985-01-01T23:59:59.000Z

375

Effects of equation of state on hydrodynamic expansion, spectra and flow harmonics  

E-Print Network [OSTI]

We perform a systematic study of the role played by the equation of state in the hydrodynamic evolution of the matter produced in relativistic heavy ion collisions. By using the same initial conditions and freeze-out scenario, the effects of different equations of state are compared by calculating their respective hydrodynamical evolution, particle spectra and elliptic flow parameter $v_2$. Three different types of equation of state are studied, each focusing on different features, such as the nature of the phase transition, as well as strangeness and baryon densities. Different equations of state imply different hydrodynamic responses, the impact thereof on final state anisotropies are investigated. The results of our calculations are compared to the data of two RHIC energies, 130 GeV and 200 GeV. It is found that the three equations of state used in the calculations describe the data reasonably well; differences can be observed, but they are quite small. The insensitivity to the equation of state weakens th...

Dudek, Danuce M; Wu, Chen; Socolowski, Otavio; Padula, Sandra S; Krein, Gastao; Hama, Yogiro; Kodama, Takeshi

2014-01-01T23:59:59.000Z

376

Three-dimensional CFD simulation of hydrodynamics in an interconnected fluidized bed for chemical looping combustion  

Science Journals Connector (OSTI)

Abstract A hydrodynamic model of an interconnected fluidized bed for chemical looping combustion was established based on the Eulerian–Eulerian two-fluid model with the kinetic theory of granular flow. The effect of the drag model on the computational results was investigated and detailed hydrodynamics were predicted in the three-dimensional circulating fluidized bed (composed of a riser, bubbling bed, pot-seal and cyclone). Both qualitative and quantitative results indicated that the drag model had a significant effect on the flow behavior. The Gidaspow and the Syamlal & O'Brien drag models both produced accurate predictions in this study. The pressure balance of an interconnected fluidized bed revealed that the pressure in the bubbling bed was lower than that in the pot-seal and the riser, whilst still being higher than the pressure in the cyclone. The riser and bubbling bed were individually operated in fast and bubbling fluidization regions. The three distinct regions identified from the bottom to the top of the riser were: entrance region, bulk region and exit region. The solids volume fraction was higher in the near-wall region but lower in the center region for both the riser and bubbling bed. The coupled characteristics of the fluidized bed were predominantly identified by the strong effect of operational gas velocity in the riser on the hydrodynamics in the bubbling bed.

Yanjun Guan; Jian Chang; Kai Zhang; Baodong Wang; Qi Sun

2014-01-01T23:59:59.000Z

377

Gaussian approximation for finitely extensible bead-spring chains with hydrodynamic interaction  

E-Print Network [OSTI]

The Gaussian Approximation, proposed originally by Ottinger [J. Chem. Phys., 90 (1) : 463-473, 1989] to account for the influence of fluctuations in hydrodynamic interactions in Rouse chains, is adapted here to derive a new mean-field approximation for the FENE spring force. This "FENE-PG" force law approximately accounts for spring-force fluctuations, which are neglected in the widely used FENE-P approximation. The Gaussian Approximation for hydrodynamic interactions is combined with the FENE-P and FENE-PG spring force approximations to obtain approximate models for finitely-extensible bead-spring chains with hydrodynamic interactions. The closed set of ODE's governing the evolution of the second-moments of the configurational probability distribution in the approximate models are used to generate predictions of rheological properties in steady and unsteady shear and uniaxial extensional flows, which are found to be in good agreement with the exact results obtained with Brownian dynamics simulations. In particular, predictions of coil-stretch hysteresis are in quantitative agreement with simulations' results. Additional simplifying diagonalization-of-normal-modes assumptions are found to lead to considerable savings in computation time, without significant loss in accuracy.

R. Prabhakar; J. Ravi Prakash

2006-02-07T23:59:59.000Z

378

Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate-Scale Hydrodynamic Model  

SciTech Connect (OSTI)

The Washington State Department of Ecology contracted with Pacific Northwest National Laboratory to develop an intermediate-scale hydrodynamic and water quality model to study dissolved oxygen and nutrient dynamics in Puget Sound and to help define potential Puget Sound-wide nutrient management strategies and decisions. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or dominate human impacts to dissolved oxygen levels in the sensitive areas. In this study, an intermediate-scale hydrodynamic model of Puget Sound was developed to simulate the hydrodynamics of Puget Sound and the Northwest Straits for the year 2006. The model was constructed using the unstructured Finite Volume Coastal Ocean Model. The overall model grid resolution within Puget Sound in its present configuration is about 880 m. The model was driven by tides, river inflows, and meteorological forcing (wind and net heat flux) and simulated tidal circulations, temperature, and salinity distributions in Puget Sound. The model was validated against observed data of water surface elevation, velocity, temperature, and salinity at various stations within the study domain. Model validation indicated that the model simulates tidal elevations and currents in Puget Sound well and reproduces the general patterns of the temperature and salinity distributions.

Yang, Zhaoqing; Khangaonkar, Tarang; Labiosa, Rochelle G.; Kim, Taeyun

2010-11-30T23:59:59.000Z

379

Initialization of hydrodynamics in relativistic heavy ion collisions with an energy-momentum transport model  

E-Print Network [OSTI]

A key ingredient of hydrodynamical modeling of relativistic heavy ion collisions is thermal initial conditions, an input that is the consequence of a pre-thermal dynamics which is not completely understood yet. In the paper we employ a recently developed energy-momentum transport model of the pre-thermal stage to study influence of the alternative initial states in nucleus-nucleus collisions on flow and energy density distributions of the matter at the starting time of hydrodynamics. In particular, the dependence of the results on isotropic and anisotropic initial states is analyzed. It is found that at the thermalization time the transverse flow is larger and the maximal energy density is higher for the longitudinally squeezed initial momentum distributions. The results are also sensitive to the relaxation time parameter, equation of state at the thermalization time, and transverse profile of initial energy density distribution: Gaussian approximation, Glauber Monte Carlo profiles, etc. Also, test results ensure that the numerical code based on the energy-momentum transport model is capable of providing both averaged and fluctuating initial conditions for the hydrodynamic simulations of relativistic nuclear collisions.

V. Yu. Naboka; S. V. Akkelin; Iu. A. Karpenko; Yu. M. Sinyukov

2015-01-14T23:59:59.000Z

380

Hydrodynamic flow in the vicinity of a nanopore induced by an applied voltage  

Science Journals Connector (OSTI)

Continuum simulation is employed to study ion transport and fluid flow through a nanopore in a solid-state membrane under an applied potential drop. The results show the existence of concentration polarization layers on the surfaces of the membrane. The nonuniformity of the ionic distribution gives rise to an electric pressure that drives vortical motion in the fluid. There is also a net hydrodynamic flow through the nanopore due to an asymmetry induced by the membrane surface charge. The qualitative behavior is similar to that observed in a previous study using molecular dynamic simulations. The current–voltage characteristics show some nonlinear features but are not greatly affected by the hydrodynamic flow in the parameter regime studied. In the limit of thin Debye layers, the electric resistance of the system can be characterized using an equivalent circuit with lumped parameters. Generation of vorticity can be understood qualitatively from elementary considerations of the Maxwell stresses. However, the flow strength is a strongly nonlinear function of the applied field. Combination of electrophoretic and hydrodynamic effects can lead to ion selectivity in terms of valences and this could have some practical applications in separations.

Mao Mao; Sandip Ghosal; Guohui Hu

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Hydrodynamic flow in the vicinity of a nanopore induced by an applied voltage  

E-Print Network [OSTI]

Continuum simulation is employed to study ion transport and fluid flow through a nanopore in a solid-state membrane under an applied potential drop. Results show the existence of concentration polarization layers on the surfaces of the membrane. The nonuniformity of the ionic distribution gives rise to an electric pressure that drives vortical motion in the fluid. There is also a net hydrodynamic flow through the nanopore due to an asymmetry induced by the membrane surface charge. The qualitative behavior is similar to that observed in a previous study using molecular dynamic simulations. The current--voltage characteristics show some nonlinear features but are not greatly affected by the hydrodynamic flow in the parameter regime studied. In the limit of thin Debye layers, the electric resistance of the system can be characterized using an equivalent circuit with lumped parameters. Generation of vorticity can be understood qualitatively from elementary considerations of the Maxwell stresses. However, the flow strength is a strongly nonlinear function of the applied field. Combination of electrophoretic and hydrodynamic effects can lead to ion selectivity in terms of valences and this could have some practical applications in separations.

Mao Mao; Sandip Ghosal; Guohui Hu

2013-05-16T23:59:59.000Z

382

High-energy Particle Transport in Three-dimensional Hydrodynamic Models of Colliding-wind Binaries  

Science Journals Connector (OSTI)

Massive stars in binary systems (such as WR 140, WR 147, or ? Carinae) have long been regarded as potential sources of high-energy ?-rays. The emission is thought to arise in the region where the stellar winds collide and produce relativistic particles that subsequently might be able to emit ?-rays. Detailed numerical hydrodynamic simulations have already offered insight into the complex dynamics of the wind collision region (WCR), while independent analytical studies, albeit with simplified descriptions of the WCR, have shed light on the spectra of charged particles. In this paper, we describe a combination of these two approaches. We present a three-dimensional hydrodynamical model for colliding stellar winds and compute spectral energy distributions of relativistic particles for the resulting structure of the WCR. The hydrodynamic part of our model incorporates the line-driven acceleration of the winds, gravity, orbital motion, and the radiative cooling of the shocked plasma. In our treatment of charged particles, we consider diffusive shock acceleration in the WCR and the subsequent cooling via inverse Compton losses (including Klein-Nishina effects), bremsstrahlung, collisions, and other energy loss mechanisms.

K. Reitberger; R. Kissmann; A. Reimer; O. Reimer; G. Dubus

2014-01-01T23:59:59.000Z

383

Hydrodynamic motion of a large prestressed concrete bucket foundation for offshore wind turbines  

Science Journals Connector (OSTI)

A large prestressed concrete bucket foundation (LPCBF) was used for the first offshore wind turbine in the Qidong sea area of Jiangsu Province in China. The most critical technique of the foundation is the self-floating towing technique based on a reasonable subdivision inside the bucket. To predict the dynamic behaviors of the LPCBF in waves supported by the air cushion the hydrodynamic software MOSES is used to simulate the three-dimensional motion of the foundation in the towing construction site. The prototype foundation models are established using MOSES with a water draft of 4?m 5?m and 6?m in given environmental conditions. The results show that the hydrodynamic responses of the large floater with air cushions depend not only on the wave conditions but also on the mass of the water column air cushion height and air pressure distribution. In addition the hydrodynamic characteristics can be tuned resulting in small dynamic responses in a particular sea state by changing the draft and water plug height. The floating technique of the LPCBF with supported air cushions in waves is highly competitive for saving cost while using few expensive types of equipment during the towing transportation.

Puyang Zhang; Hongyan Ding; Conghuan Le

2013-01-01T23:59:59.000Z

384

Proceedings of RIKEN BNL Research Center Workshop entitled Hydrodynamics in Heavy Ion Collisions and QCD Equation of State (Volume 88)  

SciTech Connect (OSTI)

The interpretation of relativistic heavy-ion collisions at RHIC energies with thermal concepts is largely based on the relative success of ideal (nondissipative) hydrodynamics. This approach can describe basic observables at RHIC, such as particle spectra and momentum anisotropies, fairly well. On the other hand, recent theoretical efforts indicate that dissipation can play a significant role. Ideally viscous hydrodynamic simulations would extract, if not only the equation of state, but also transport coefficients from RHIC data. There has been a lot of progress with solving relativistic viscous hydrodynamics. There are already large uncertainties in ideal hydrodynamics calculations, e.g., uncertainties associated with initial conditions, freezeout, and the simplified equations of state typically utilized. One of the most sensitive observables to the equation of state is the baryon momentum anisotropy, which is also affected by freezeout assumptions. Up-to-date results from lattice quantum chromodynamics on the transition temperature and equation of state with realistic quark masses are currently available. However, these have not yet been incorporated into the hydrodynamic calculations. Therefore, the RBRC workshop 'Hydrodynamics in Heavy Ion Collisions and QCD Equation of State' aimed at getting a better understanding of the theoretical frameworks for dissipation and near-equilibrium dynamics in heavy-ion collisions. The topics discussed during the workshop included techniques to solve the dynamical equations and examine the role of initial conditions and decoupling, as well as the role of the equation of state and transport coefficients in current simulations.

Karsch,F.; Kharzeev, D.; Molnar, K.; Petreczky, P.; Teaney, D.

2008-04-21T23:59:59.000Z

385

Effects of open boundary location on the far-field hydrodynamics of a Severn Barrage  

Science Journals Connector (OSTI)

Abstract The Severn Estuary has the second largest tide range in the world and a barrage across the estuary from Cardiff in South Wales to Weston in South West England has been proposed for over half a century, to extract large amounts of tidal energy from the estuary. To assess the environmental impacts of the proposed tidal barrage requires accurate model predictions of both the near-field and far-field hydrodynamics, which can strongly depend on the model area and the appropriate boundary forcing. In this paper two models, based on the Environmental Fluid Dynamics Code (EFDC) numerical model with a recently-developed Barrage module (EFDC_B), were set up with different computational domains. The Continental Shelf model, which was centred on the Bristol Channel, has its open boundary extended to beyond the Continental Shelf. The Irish Sea model, which was also centred around the Bristol Channel, only has its open boundary extended to the Celtic Sea in the south and the Irish Sea in the north. In order to investigate the effects of the open boundary conditions imposed in the models on the near and far-field hydrodynamics for the case of the Severn Barrage, the Continental Shelf model was first run with and without the operation of the Severn Barrage. The Irish Sea model was then run, also with and without the operation of the Severn Barrage, and with the open boundary conditions provided by the Continental Shelf model. The results from both models were then analysed to study the impact of the tidal barrage on the near-field and far-field hydrodynamics in the Bristol Channel and Irish Sea. Detailed comparisons of the model results indicate that the hydrodynamic conditions along the open boundaries of the Irish Sea model are affected by the tidal barrage and that the open boundary conditions also have noticeable impacts on the far-field hydrodynamics, especially in the Irish Sea, with approximately an average 4–7 cm difference in the maximum water levels predicted in Cardigan Bay and with a maximum difference of 9 cm in the northern part of Cardigan Bay.

Juntao Zhou; Shunqi Pan; Roger A. Falconer

2014-01-01T23:59:59.000Z

386

On-Axis Brilliance and Power of In-Vacuum Undulators for The Advanced Photon Source  

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

4 4 On-Axis Brilliance and Power of In-Vacuum Undulators for the Advanced Photon Source (formerly MD-TN-2009-004) R. Dejus, M. Jaski, and S.H. Kim - MD Group/ASD Rev. 1, November 25, 2009: Updated the fitted B eff in Tables 1 - 3, and 5 to use two decimals in the fitted equation. Explained chosen gaps. Added clarifications in the text and added additional references. Edited by C. Eyberger for release as cleared document ANL/APS/LS-314; updated in ICMS. Rev. 0a, June 17, 2009: ICMS Initial Release (minor clarifications and corrections of typographical errors, added footnote "d" to Table 4). Rev. 0, June 16, 2009: First Release as Technical Note MD-TN-2009-004. Table of Contents Introduction ......................................................................................................................... 2

387

Combined Experiment Phase 1. [Horizontal axis wind turbines: wind tunnel testing versus field testing  

SciTech Connect (OSTI)

How does wind tunnel airfoil data differ from the airfoil performance on an operating horizontal axis wind turbine (HAWT) The National Renewable Energy laboratory has been conducting a comprehensive test program focused on answering this question and understanding the basic fluid mechanics of rotating HAWT stall aerodynamics. The basic approach was to instrument a wind rotor, using an airfoil that was well documented by wind tunnel tests, and measure operating pressure distributions on the rotating blade. Based an the integrated values of the pressure data, airfoil performance coefficients were obtained, and comparisons were made between the rotating data and the wind tunnel data. Care was taken to the aerodynamic and geometric differences between the rotating and the wind tunnel models. This is the first of two reports describing the Combined Experiment Program and its results. This Phase I report covers background information such as test setup and instrumentation. It also includes wind tunnel test results and roughness testing.

Butterfield, C.P.; Musial, W.P.; Simms, D.A.

1992-10-01T23:59:59.000Z

388

The determination of stochastic loads on horizontal axis wind turbine blades  

SciTech Connect (OSTI)

The FAST Code which is capable of determining structural loads of a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees-of-freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and the code models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good.

Freeman, L.N.; Wilson, R.E. [Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering

1998-05-01T23:59:59.000Z

389

Microsoft Word - newletter August 2007 v5.doc  

National Nuclear Security Administration (NNSA)

Office of Defense Science Office of Defense Science Quarterly Newsletter August 2007 Inside This Issue 1 Message from the Director 2 THERMOS - A Small-Scale Experimental and Computational Study of Plutonium Deformation/ Damage/Failure Physics 3 Dual Axis Radiographic Hydrodynamics Test (DARHT) 2 nd Axis Achieves Full Accelerator Configuration 5 Science Campaigns Support High-Impact Basic Research 7 New Appointment and Awards Chris Deeney, Director, Office of Defense Science Welcome to the inaugural issue of the Office of Defense Science newsletter! These newsletters will communicate two themes important to the Office of Defense Science (also know as

390

Design of a Thermal Imaging Diagnostic Using 90-Degree, Off-Axis, Parabolic Mirrors  

SciTech Connect (OSTI)

Thermal imaging is an important, though challenging, diagnostic for shockwave experiments. Shock-compressed materials undergo transient temperature changes that cannot be recorded with standard (greater than ms response time) infrared detectors. A further complication arises when optical elements near the experiment are destroyed. We have designed a thermal-imaging system for studying shock temperatures produced inside a gas gun at Sandia National Laboratories. Inexpensive, diamond-turned, parabolic mirrors relay an image of the shocked target to the exterior of the gas gun chamber through a sapphire vacuum port. The 3000–5000-nm portion of this image is directed to an infrared camera which acquires a snapshot of the target with a minimum exposure time of 150 ns. A special mask is inserted at the last intermediate image plane, to provide dynamic thermal background recording during the event. Other wavelength bands of this image are split into high-speed detectors operating at 900–1700 nm, and at 1700–3000 nm for timeresolved pyrometry measurements. This system incorporates 90-degree, off-axis parabolic mirrors, which can collect low f/# light over a broad spectral range, for high-speed imaging. Matched mirror pairs must be used so that aberrations cancel. To eliminate image plane tilt, proper tip-to-tip orientation of the parabolic mirrors is required. If one parabolic mirror is rotated 180 degrees about the optical axis connecting the pair of parabolic mirrors, the resulting image is tilted by 60 degrees. Different focal-length mirrors cannot be used to magnify the image without substantially sacrificing image quality. This paper analyzes performance and aberrations of this imaging diagnostic.

Malone, Robert M.; Becker, Steven A.; Dolan, Daniel H.; Hacking, Richard G.; Hickman, Randy J.; Kaufman, Morris I.; Stevens, Gerald D.; Turley, William D.

2006-09-01T23:59:59.000Z

391

Electron cyclotron resonance near the axis of the gas-dynamic trap  

SciTech Connect (OSTI)

Propagation of an extraordinary electromagnetic wave in the vicinity of electron cyclotron resonance surface in an open linear trap is studied analytically, taking into account inhomogeneity of the magnetic field in paraxial approximation. Ray trajectories are derived from a reduced dispersion equation that makes it possible to avoid the difficulty associated with a transition from large propagation angles to the case of strictly longitudinal propagation. Our approach is based on the theory, originally developed by Zvonkov and Timofeev [Sov. J. Plasma Phys. 14, 743 (1988)], who used the paraxial approximation for the magnetic field strength, but did not consider the slope of the magnetic field lines, which led to considerable error, as has been recently noted by Gospodchikov and Smolyakova [Plasma Phys. Rep. 37, 768-774 (2011)]. We have found ray trajectories in analytic form and demonstrated that the inhomogeneity of both the magnetic field strength and the field direction can qualitatively change the picture of wave propagation and significantly affect the efficiency of electron cyclotron heating of a plasma in a linear magnetic trap. Analysis of the ray trajectories has revealed a criterion for the resonance point on the axis of the trap to be an attractor for the ray trajectories. It is also shown that a family of ray trajectories can still reach the resonance point on the axis if the latter generally repels the ray trajectories. As an example, results of general theory are applied to the electron cyclotron resonance heating experiment which is under preparation on the gas dynamic trap in the Budker Institute of Nuclear Physics [Shalashov et al., Phys. Plasmas 19, 052503 (2012)].

Bagulov, D. S. [Novosibirsk State University, Pirogova Street 2, Novosibirsk (Russian Federation); Kotelnikov, I. A. [Novosibirsk State University, Pirogova Street 2, Novosibirsk (Russian Federation); Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences, Akademika Lavrentyeva Prospect 11, 630090 Novosibirsk (Russian Federation)

2012-08-15T23:59:59.000Z

392

Determining the neutrino mass hierarchy and CP violation in NoVA with a second off-axis detector  

SciTech Connect (OSTI)

We consider a Super-NOVA-like experimental configuration based on the use of two detectors in a long-baseline experiment as NOVA. We take the far detector as in the present NOVA proposal and add a second detector at a shorter baseline. The location of the second off-axis detector is chosen such that the ratio L/E is the same for both detectors, being L the baseline and E the neutrino energy. We consider liquid argon and water- Cerenkov techniques for the second off-axis detector and study, for different experimental setups, the detector mass required for the determination of the neutrino mass hierarchy, for different values of {theta}{sub 13}. We also study the capabilities of such an experimental setup for determining CP-violation in the neutrino sector. Our results show that by adding a second off-axis detector a remarkable enhancement on the capabilities of the current NOVA experiment could be achieved.

Mena, Olga; /Fermilab; Palomares-Ruiz, Sergio; /Vanderbilt U.; Pascoli, Silvia; /CERN /Durham U., IPPP

2005-10-01T23:59:59.000Z

393

Impact of different tidal renewable energy projects on the hydrodynamic processes in the Severn Estuary, UK  

Science Journals Connector (OSTI)

The Severn Estuary, located in the UK between south east Wales and south west England, is an ideal site for tidal renewable energy projects, since this estuary has the third highest tidal range in the world, with a spring tidal range approaching 14 m. The UK Government recently invited proposals for tidal renewable energy projects from the estuary and many proposals were submitted for consideration. Among the proposals submitted and subsequently shortlisted were: the Cardiff–Weston Barrage, the Fleming Lagoon and the Shoots Barrage, all three of which are nationally public interest. Therefore a two-dimensional finite volume numerical model, based on an unstructured triangular mesh, has been refined to study the hydrodynamic impact and flood inundation extent, post construction, of all three of these proposed tidal power projects. The model-predicted hydrodynamic processes have been analysed in detail, both without and with the structures, including the discharge processes at key sections, the contours of maximum and minimum water levels, the envelope curves of high and low water levels, the maximum tidal currents, the local velocity fields around the structures and the mean power output curves. Simulated results indicate that: (i) although the construction of the Cardiff–Weston Barrage would have an adverse impact on a range of environmental aspects, due to there being approximately a 50% decrease in the peak discharge entering the upstream region, it would reduce the maximum water levels upstream of the barrage by typically 0.3–1.2 m, which could be positive in respect of coastal flooding; (ii) the construction of the Fleming Lagoon would have little influence on the hydrodynamic processes in the Severn Estuary; and (iii) the construction of the Shoots Barrage would decrease the maximum water levels upstream of the M4 bridge by between 0.3 and 1.0 m, but it could lead to an increase in the maximum water levels downstream of the barrage by typically 20–30 cm.

Junqiang Xia; Roger A. Falconer; Binliang Lin

2010-01-01T23:59:59.000Z

394

Hydrodynamic flow in lower Cretaceous Muddy sandstone, Gas Draw Field, Powder River Basin, Wyoming  

E-Print Network [OSTI]

/dx =[pj(p?- p )j (dh/dx), (4) where 8 is the angle of inclination, dz/dx is the slope of the oil- water interface, dh/dx is the horizontal component of head change, and pj(p - p ) is an amplification factor (Willis, 1961). Thus the w 0 hydrodynamic oil... reflected by Muddy thickness greater than 100 ft appears to cross the north end of Gas Draw, but 37 CHEVRON 1 FEDERAL PERMEABILITY (md) FEET 1000 100 10 I 0. 1 20 POROSITY &Im 20 10 0 WATER SATURATION 100 80 80 40 20 0 I I I I I I OIL SATURATION...

Lin, Joseph Tien-Chin

2012-06-07T23:59:59.000Z

395

Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments  

SciTech Connect (OSTI)

This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O'Toole, Brendan [UNLV; Hixson, Robert S [NSTec

2014-01-23T23:59:59.000Z

396

Hydrodynamic impact of a tidal barrage in the Severn Estuary, UK  

Science Journals Connector (OSTI)

The Severn Estuary has a spring tidal range approaching 14 m, which is among the highest tides in the world. Various proposals have been made regarding the construction of a tidal barrage across the estuary to enable tidal energy to be generated. The aim of the current study is to investigate the impact of constructing a tidal barrage on the hydrodynamic processes in the Severn Estuary using a numerical model. A two-dimensional hydrodynamic model based on an unstructured triangular mesh has been used in this study. The model employs a TVD finite volume method to solve the 2D shallow water equations, with the numerical scheme being second-order accurate in both time and space. The model has been calibrated by comparing model predictions with observed tidal levels and currents at different sites, for typical spring and neap tides, and it has also been verified using tidal level time series at four tide gauging stations measured in 2003. In order to predict the hydrodynamic processes with a barrage, the model domain was divided into two subdomains: one each side of the barrage. Details were given of the method used for representing the various hydraulic structures, including the sluices and turbines, along the proposed Cardiff-Weston barrage. The impact of constructing the barrage on the water levels and velocities was then investigated using this model. Model-predicted hydrodynamic parameters, without and with the barrage, were analysed in detail. Model predictions indicated that with the barrage the mean power output could reach 2.0 GW with up to 25 GWh units of electricity being generated over a typical mean spring tidal cycle. At some cross-sections, the maximum discharges were predicted to decrease by 30–50%, as compared with the corresponding discharges predicted without the barrage. The model also predicted that with the barrage, the maximum water levels upstream of the barrage would decrease by 0.5–1.5 m, and with the peak tidal currents also being reduced considerably. For different operating modes, complex velocity fields were predicted to occur in the vicinity of the barrage.

Junqiang Xia; Roger A. Falconer; Binliang Lin

2010-01-01T23:59:59.000Z

397

Knudsen-to-Hydrodynamic Crossover in Liquid He3 in a High-Porosity Aerogel  

Science Journals Connector (OSTI)

We present a combined experimental and theoretical study of the drag force acting on a high porosity aerogel immersed in liquid He3 and its effect on sound propagation. The drag force is characterized by the Knudsen number, which is defined as the ratio of the quasiparticle mean free path to the radius of an aerogel strand. Evidence of the Knudsen-hydrodynamic crossover is clearly demonstrated by a drastic change in the temperature dependence of ultrasound attenuation in 98% porosity aerogel. Our theoretical analysis shows that the frictional sound damping caused by the drag force is governed by distinct laws in the two regimes, providing excellent agreement with the experimental observation.

H. Takeuchi; S. Higashitani; K. Nagai; H. C. Choi; B. H. Moon; N. Masuhara; M. W. Meisel; Y. Lee; N. Mulders

2012-06-01T23:59:59.000Z

398

Macrostatistical hydrodynamics  

SciTech Connect (OSTI)

During the course of these efforts we have been studying suspension of particles in Newtonian and non-Newtonian liquids, embodying a combination of analysis, experiments, and numerical simulations. Experiments primarily involved tracking small balls as they fall slowly through otherwise quiescent suspensions of neutrally buoyant particles. Detailed trajectories of the balls, obtained either with new experimental techniques or by numerical simulation, were statistically interpreted in terms of the mean settling velocity and the dispersion about the mean. We showed that falling-ball rheometry, using small balls relative to the suspended particles, could be a means of measuring the macroscopic zero-shear-rate viscosity without significantly disturbing the original microstructure; therefore, falling-ball rheometry can be a powerful tool for use in studying the effects of microstructures on the macroscopic properties of suspensions. We plan to extend this work to the study of more complex, structured fluids, and to use other tools (e.g., rolling-ball rheometry) to study boundary effects. We also propose to study flowing suspensions to obtain non-zero-shear-rate viscosities. The intent is to develop an understanding of the basic principles needed to treat generic multiphase flow problems, through a detailed study of model systems. 8 refs.

Brenner, H.

1992-01-01T23:59:59.000Z

399

Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA  

SciTech Connect (OSTI)

Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of ? ? 4, an implosion velocity of 3.8?×?10{sup 7}?cm/s, and a laser intensity of ?10{sup 15}?W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); and others

2014-05-15T23:59:59.000Z

400

Accurate registration of random radiographic projections based on three spherical references for the purpose of few-view 3D reconstruction  

SciTech Connect (OSTI)

Precise registration of radiographic projection images acquired in almost arbitrary geometries for the purpose of three-dimensional (3D) reconstruction is beset with difficulties. We modify and enhance a registration method [R. Schulze, D. D. Bruellmann, F. Roeder, and B. d'Hoedt, Med. Phys. 31, 2849-2854 (2004)] based on coupling a minimum amount of three reference spheres in arbitrary positions to a rigid object under study for precise a posteriori pose estimation. Two consecutive optimization procedures (a, initial guess; b, iterative coordinate refinement) are applied to completely exploit the reference's shadow information for precise registration of the projections. The modification has been extensive, i.e., only the idea of using the sphere shadows to locate each sphere in three dimensions from each projection was retained whereas the approach to extract the shadow information has been changed completely and extended. The registration information is used for subsequent algebraic reconstruction of the 3D information inherent in the projections. We present a detailed mathematical theory of the registration process as well as simulated data investigating its performance in the presence of error. Simulation of the initial guess revealed a mean relative error in the critical depth coordinate ranging between 2.1% and 4.4%, and an evident error reduction by the subsequent iterative coordinate refinement. To prove the applicability of the method for real-world data, algebraic 3D reconstructions from few ({<=}9) projection radiographs of a human skull, a human mandible and a teeth-containing mandible segment are presented. The method facilitates extraction of 3D information from only few projections obtained from off-the-shelf radiographic projection units without the need for costly hardware. Technical requirements as well as radiation dose are low.

Schulze, Ralf; Heil, Ulrich; Weinheimer, Oliver; Gross, Daniel; Bruellmann, Dan; Thomas, Eric; Schwanecke, Ulrich; Schoemer, Elmar [Department of Oral Surgery (and Oral Radiology), Johannes Gutenberg-University, Dental School, Mainz 55131 (Germany); Institute of Computer Science, Johannes Gutenberg-University, Mainz 55131 (Germany); Department of Oral Surgery (and Oral Radiology), Johannes Gutenberg-University, Dental School, Mainz 55131 (Germany); Department of Design, Computer Science and Media, University of Applied Sciences, Wiesbaden 65195 (Germany); Institute of Computer Science, Johannes Gutenberg-University, Mainz 55131 (Germany)

2008-02-15T23:59:59.000Z

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401

Direct synthesis and easy axis alignment of L1{sub 0}-FePt nanoparticles  

SciTech Connect (OSTI)

Partially ordered Fe{sub 53}Pt{sub 47} nanoparticles with size around 8 nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. The reflux temperature of the solution could exceed 360 deg. C, where disordered FePt particles could be partially transformed into the ordered L1{sub 0} phase. A nonmagnetic mechanical stirrer was used in order to avoid agglomeration of the fct-FePt particles during synthesis. The particles were dispersed in toluene and films of the particles were cast onto silicon wafers from the solution. X-ray diffraction patterns of as-made samples showed weak superlattice peaks, indicating partial chemical ordering of the Fe{sub 53}Pt{sub 47} particles. The room-temperature hysteresis loop of the as-made sample reveals a small coercivity ({approx}600 Oe) because of thermal fluctuations; however, the loop is wide open and hard to saturate. The remanence coercivity from the dcd curve is about 2.5 kOe, which is four times larger than the hysteresis coercivity. The large remanent to hysteresis coercivity ratio and the shapes of the hysteresis loop and dcd curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the ordered nanoparticles with a polymer binder, the easy axis of the particles could be aligned under an external field.

Kang Shishou; Jia Zhiyong; Shi Shifan; Nikles, David E.; Harrell, J.W. [Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487-0209 (United States)

2005-05-15T23:59:59.000Z

402

A study of the abundance distributions along the minor axis of the Galactic bulge  

Science Journals Connector (OSTI)

I report the preliminary results of a project in collaboration with R. Michael Rich (Columbia) where we derive heavy element abundances for hundreds of K?giants in seven windows of low extinction along or near the minor axis of the Galactic bulge. By using the recently?calibrated Washington photometric filter system the distribution function in [Fe/H] is determined for each field. Within 8° of the Galactic center (?1 kpc) our data are consistent with no gradient in the distribution of [Fe/H] which may hint to a dissipationless collapse and/or sufficient mixing during the star?forming epoch when Fe was produced in the bulge. The mean abundance over this region is between two and five times solar. The form of these distributions is well?fitted by the simple (closed box) model of chemical evolution where the bulge is self?enriched by processing its original gas content to completion. Beyond 8° from the Galactic center our data show that the mean of the abundance distributions drops precipitously. This is consistent with the notion that the inner bulge is chemically distinct from the halo. It may be possible to use kinematics to disentangle the two populations via a radial velocity survey.

Neil D. Tyson

1992-01-01T23:59:59.000Z

403

Thermodynamic study of c-axis-oriented epitaxial Pb(Zr,Ti)O3 thin films  

Science Journals Connector (OSTI)

Thermodynamic characteristics of single crystalline Pb(Zr0.52Ti0.48)O3 (PZT) were investigated using c-axis oriented PZT films. The PZT films were epitaxially grown on Pt/MgO substrate and dielectric and ferroelectric properties were measured as a function of one-dimensional stress. The stress dependence of dielectric and ferroelectric properties was examined on the basis of the Landau-Devonshire’s phenomenological theory and the free energy coefficients of single crystalline PZT films were obtained. The dielectric stiffness coefficients and electrostrictive coefficient of epitaxial PZT films were obtained to be ?1=-1.30×108 (m/F), ?11=3.07×108 (m5/C2F), ?111=-3.11×107 (m9/C2F), and Q12=-5.70×10-2 (m4/C2), which are different from the values derived from the analysis of polycrystalline PZT. The temperature dependence of dielectric constant of the PZT films showed clear Curie-Weiss law and the dielectric stiffness coefficient ?1 derived from this measurement was almost same value from the analysis of stress dependence of the dielectricity of the epitaxial PZT films.

Isaku Kanno; Yu Yokoyama; Hidetoshi Kotera; Kiyotaka Wasa

2004-02-12T23:59:59.000Z

404

Horizontal-axis wind-system rotor performance model comparison: a compendium  

SciTech Connect (OSTI)

This compendium consists of four reports, the purpose of which is to evaluate performance prediction methods for horizontal-axis wind turbines. The reports were prepared by four separate contractors. Oregon State University, AeroVironment, Inc., Aerospace Systems, Inc., and United Technologies Research Center (UTRC). Three of the four contractors used a blade-element/momentum analysis, while the fourth (UTRC) utilized a lifting line/prescribed wake analysis. These contractors were to apply their prediction methods to two rotors, that of the Enertech 1500 and that of the 1/3-scale UTRC 8 kW turbines. Results from the four prediction methods are compared with actual test data gathered via Controlled Velocity Testing (CVT), carried out by the Rocky Flats Wind Energy Research Center, operated by Rockwell International for the US Department of Energy. The conclusions of the four reports are reviewed in an introduction prepared by Rockwell International. For the Enertech 1500, rotor performance predictions closely agreed with CVT data. Yet, because of the lack of high tip speed ratio data, verification of the Glauert momentum theory was not possible. Predictions regarding the UTRC 1/3 scale 8 kW rotor did not agree well with test results. The reasons cited for the discrepancies center on inadequate airfoil section data and the varying blade pitch angles of the unique UTRC flexbeam rotor.

Not Available

1983-02-01T23:59:59.000Z

405

A numerical method for calculation of power output from ducted vertical axis hydro-current turbines  

Science Journals Connector (OSTI)

Abstract This paper investigates effects of ducting on power output from vertical axis hydro-current turbines. A numerical two-dimensional method based on the potential flow theory is developed for calculation of non-dimensional power output from these turbines. In this method, the blades are represented by vortex filaments. The vortex shedding from the blades is modeled by discrete vortices. A boundary element method is used to incorporate the duct shape which is represented by a series of panels with constant distributions of sources and doublets. The aerodynamic loading on the blades are calculated using a quasi-steady modeling. A time-marching scheme is used for implementation of the numerical method. The results of this method are compared with experimental results for a turbine model. A good correlation between the numerical and experimental results is obtained for tip speed ratios equal and higher than 2.25. However due to a lack of dynamic stall modeling, the numerical method is not able to predict power output accurately at lower tip speed ratios wherein effects of dynamic stall are significant. Both numerical and experimental results also showed that the power output from a turbine can increase significantly when it is enclosed within a well-designed duct. The maximum power output of the turbine model investigated in this paper showed a 74% increase when the turbine is operating within the duct relative to the case it is in free-stream conditions.

Mahmoud Alidadi; Sander Calisal

2014-01-01T23:59:59.000Z

406

Evaluation of servo, geometric and dynamic error sources on five axis high-speed machine tool  

E-Print Network [OSTI]

Many sources of errors exist in the manufacturing process of complex shapes. Some approximations occur at each step from the design geometry to the machined part. The aim of the paper is to present a method to evaluate the effect of high speed and high dynamic load on volumetric errors at the tool center point. The interpolator output signals and the machine encoder signals are recorded and compared to evaluate the contouring errors resulting from each axis follow-up error. The machine encoder signals are also compared to the actual tool center point position as recorded with a non-contact measuring instrument called CapBall to evaluate the total geometric errors. The novelty of the work lies in the method that is proposed to decompose the geometric errors in two categories: the quasi-static geometric errors independent from the speed of the trajectory and the dynamic geometric errors, dependent on the programmed feed rate and resulting from the machine structure deflection during the acceleration of its axes...

Andolfatto, Loïc; Mayer, René

2011-01-01T23:59:59.000Z

407

Darrieus vertical axis wind turbine for power generation I: Assessment of Darrieus VAWT configurations  

Science Journals Connector (OSTI)

Abstract This paper aims to assess the Darrieus vertical axis wind turbine (VAWT) configurations, including the drawbacks of each variation that hindered the development into large scale rotor. A comprehensive timeline is given as a lineage chart. The variations are assessed on the performance, components and operational reliability. In addition, current development and future prospects of Darrieus VAWT are presented. The Darrieus VAWT patented in France in 1925 and in the US in 1931 had two configurations: (i) curved blades and (ii) straight blades configurations. Curved blades configuration (egg-beater or phi-rotor) has evolved from the conventional guy-wires support into fixed-on-tower and cantilevered versions. Straight blades configuration used to have variable-geometry (Musgrove-rotor), variable-pitch (Giromill), Diamond, Delta and V/Y rotor variations. They were stopped due to low economical value, i.e. high specific cost of energy (COE). Musgrove-rotor has evolved into fixed-pitch straight-bladed H-rotor (referred as H-rotor in this paper for simplicity). H-rotor, in turn, has evolved into several variations: Articulating, Tilted and Helical H-rotors.

Willy Tjiu; Tjukup Marnoto; Sohif Mat; Mohd Hafidz Ruslan; Kamaruzzaman Sopian

2015-01-01T23:59:59.000Z

408

Applying micro scales of horizontal axis wind turbines for operation in low wind speed regions  

Science Journals Connector (OSTI)

Abstract Utilizing the micro scales of wind turbines could noticeably supply the demand for the electricity in low wind speed regions. Aerodynamic design and optimization of the blade, as a main part of a wind turbine, were addressed in the study. Three micro scales of horizontal axis wind turbines with output power of 0.5, 0.75 and 1 kW were considered and the geometric optimization of the blades in terms of the two involved parameters, chord and twist, was undertaken. In order to improve the performance of the turbines at low wind speeds, starting time was included in an objective function in addition to the output power – the main and desirable goal of the wind turbine blade design. A purpose-built genetic algorithm was employed to maximize both the output power and the starting performance which were calculated by the blade-element momentum theory. The results emphasize that the larger values of the chord and twist at the root part of the blades are indispensable for the better performance when the wind speed is low. However, the noticeable value of the generator resistive torque could largely delay the starting of the micro-turbines especially for the considered smaller size, 0.5 kW, where the starting aerodynamic torque could not overcome the generator resistive torque. For that size, an increase in the number of blades improved both the starting performance and also output power.

Abolfazl Pourrajabian; Reza Ebrahimi; Masoud Mirzaei

2014-01-01T23:59:59.000Z

409

Turbulence effects on the wake flow and power production of a horizontal-axis wind turbine  

Science Journals Connector (OSTI)

Abstract This study experimentally investigated the effects of ambient turbulence on the wake flows and power production of a horizontal-axis wind turbine. The approaching flows included low-turbulence smooth flow and grid-generated turbulent flow. The profiles of time-averaged velocity, turbulence intensity and Reynolds stress from the intermediate to the far-wake regions were measured and compared for smooth and turbulent flows. Based on the measured data, prediction models for the centerline velocity deficit, turbulence intensity, wake radius and velocity profile were proposed. In addition, the experimental results showed that the power productions in the grid-generated turbulent flows were slightly higher than that in the smooth flow. But the power loss due to the velocity deficit in the wake flow was larger than 50% when the downwind distance was less than 12D (D is the rotor diameter). An empirical relation between the power production and the downwind distance x and lateral distance y was proposed.

Chia-Ren Chu; Pei-Hung Chiang

2014-01-01T23:59:59.000Z

410

Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind  

E-Print Network [OSTI]

Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical constraint limits the amount of power that can be extracted from a given wind farm footprint. The resulting-axis wind turbines (VAWTs) in order to achieve higher power output per unit land area than existing wind

Dabiri, John O.

411

Precision tool holder with flexure-adjustable, three degrees of freedom for a four-axis lathe  

DOE Patents [OSTI]

A precision tool holder for precisely positioning a single point cutting tool on 4-axis lathe, such that the center of the radius of the tool nose is aligned with the B-axis of the machine tool, so as to facilitate the machining of precision meso-scale components with complex three-dimensional shapes with sub-.mu.m accuracy on a four-axis lathe. The device is designed to fit on a commercial diamond turning machine and can adjust the cutting tool position in three orthogonal directions with sub-micrometer resolution. In particular, the tool holder adjusts the tool position using three flexure-based mechanisms, with two flexure mechanisms adjusting the lateral position of the tool to align the tool with the B-axis, and a third flexure mechanism adjusting the height of the tool. Preferably, the flexures are driven by manual micrometer adjusters. In this manner, this tool holder simplifies the process of setting a tool with sub-.mu.m accuracy, to substantially reduce the time required to set the tool.

Bono, Matthew J. (Pleasanton, CA); Hibbard, Robin L. (Livermore, CA)

2008-03-04T23:59:59.000Z

412

Possibility of c-axis voltage steps for a cuprate superconductor in a resonant cavity I. Tornes* and D. Stroud  

E-Print Network [OSTI]

, when driven by currents parallel to the c axis, behave like stacks of underdamped Josephson junctions's in stacks of artificial Josephson junctions. We conclude that such steps might be observable with a suitably, 74.25.Nf I. INTRODUCTION Barbara et al.1 have recently shown that underdamped Josephson-junction

Stroud, David

413

First Light of the 1.6 meter off-axis New Solar Telescope at Big Bear Solar Observatory  

E-Print Network [OSTI]

First Light of the 1.6 meter off-axis New Solar Telescope at Big Bear Solar Observatory Wenda Caoab, Nicolas Gorceixb, Roy Coulterb, Aaron Coulterb, Philip R. Goodeab aCenter for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd., Newark, NJ 07102; bBig Bear Solar

414

Thematic Week: The Role of Market Instruments in Integrated Water Management Thematic Axis: 7. Water Economics and Financing  

E-Print Network [OSTI]

Thematic Week: The Role of Market Instruments in Integrated Water Management Thematic Axis: 7. Water Economics and Financing Title: Beyond Water Marketing Myths Author: Griffin, Ronald C. Department://ron-griffin.tamu.edu, 979-845-7049. Summary: The challenge in isolating the opportunities and pitfalls of water marketing

Griffin, Ronald

415

Relativistic viscous hydrodynamics for heavy-ion collisions with ECHO-QGP  

E-Print Network [OSTI]

We present ECHO-QGP, a numerical code for $(3+1)$-dimensional relativistic viscous hydrodynamics designed for the modeling of the space-time evolution of the matter created in high energy nuclear collisions. The code has been built on top of the \\emph{Eulerian Conservative High-Order} astrophysical code for general relativistic magneto-hydrodynamics [\\emph{Del Zanna et al., Astron. Astrophys. 473, 11, 2007}] and here it has been upgraded to handle the physics of the Quark-Gluon Plasma. ECHO-QGP features second-order treatment of causal relativistic viscosity effects in both Minkowskian or Bjorken coordinates; partial or complete chemical equilibrium of hadronic species before kinetic freeze-out; initial conditions based on the optical Glauber model, including a Monte-Carlo routine for event-by-event fluctuating initial conditions; a freeze-out procedure based on the Cooper-Frye prescription. The code is extensively validated against several test problems and results always appear accurate, as guaranteed by th...

Del Zanna, L; Inghirami, G; Rolando, V; Beraudo, A; De Pace, A; Pagliara, G; Drago, A; Becattini, F

2013-01-01T23:59:59.000Z

416

Development of a Hydrodynamic Model of Puget Sound and Northwest Straits  

SciTech Connect (OSTI)

The hydrodynamic model used in this study is the Finite Volume Coastal Ocean Model (FVCOM) developed by the University of Massachusetts at Dartmouth. The unstructured grid and finite volume framework, as well as the capability of wetting/drying simulation and baroclinic simulation, makes FVCOM a good fit to the modeling needs for nearshore restoration in Puget Sound. The model domain covers the entire Puget Sound, Strait of Juan de Fuca, San Juan Passages, and Georgia Strait at the United States-Canada Border. The model is driven by tide, freshwater discharge, and surface wind. Preliminary model validation was conducted for tides at various locations in the straits and Puget Sound using National Oceanic and Atmospheric Administration (NOAA) tide data. The hydrodynamic model was successfully linked to the NOAA oil spill model General NOAA Operational Modeling Environment model (GNOME) to predict particle trajectories at various locations in Puget Sound. Model results demonstrated that the Puget Sound GNOME model is a useful tool to obtain first-hand information for emergency response such as oil spill and fish migration pathways.

Yang, Zhaoqing; Khangaonkar, Tarang P.

2007-12-10T23:59:59.000Z

417

Hydrodynamic instability growth and mix experiments at the National Ignition Facility  

SciTech Connect (OSTI)

Hydrodynamic instability growth and its effects on implosion performance were studied at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. Implosion performance and mix have been measured at peak compression using plastic shells filled with tritium gas and containing embedded localized carbon-deuterium diagnostic layers in various locations in the ablator. Neutron yield and ion temperature of the deuterium-tritium fusion reactions were used as a measure of shell-gas mix, while neutron yield of the tritium-tritium fusion reaction was used as a measure of implosion performance. The results have indicated that the low-mode hydrodynamic instabilities due to surface roughness were the primary culprits for yield degradation, with atomic ablator-gas mix playing a secondary role. In addition, spherical shells with pre-imposed 2D modulations were used to measure instability growth in the acceleration phase of the implosions. The capsules were imploded using ignition-relevant laser pulses, and ablation-front modulation growth was measured using x-ray radiography for a shell convergence ratio of ?2. The measured growth was in good agreement with that predicted, thus validating simulations for the fastest growing modulations with mode numbers up to 90 in the acceleration phase. Future experiments will be focused on measurements at higher convergence, higher-mode number modulations, and growth occurring during the deceleration phase.

Smalyuk, V. A.; Barrios, M.; Caggiano, J. A.; Casey, D. T.; Cerjan, C. J.; Clark, D. S.; Edwards, M. J.; Haan, S. W.; Hammel, B. A.; Hamza, A.; Hsing, W. W.; Hurricane, O.; Kroll, J.; Landen, O. L.; Lindl, J. D.; Ma, T.; McNaney, J. M.; Mintz, M.; Parham, T.; Peterson, J. L. [Lawrence Livermore National Laboratory, NIF Directorate, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, NIF Directorate, Livermore, California 94550 (United States); and others

2014-05-15T23:59:59.000Z

418

Relativistic viscous hydrodynamics for heavy-ion collisions with ECHO-QGP  

E-Print Network [OSTI]

We present ECHO-QGP, a numerical code for $(3+1)$-dimensional relativistic viscous hydrodynamics designed for the modeling of the space-time evolution of the matter created in high energy nuclear collisions. The code has been built on top of the \\emph{Eulerian Conservative High-Order} astrophysical code for general relativistic magneto-hydrodynamics [\\emph{Del Zanna et al., Astron. Astrophys. 473, 11, 2007}] and here it has been upgraded to handle the physics of the Quark-Gluon Plasma. ECHO-QGP features second-order treatment of causal relativistic viscosity effects in both Minkowskian or Bjorken coordinates; partial or complete chemical equilibrium of hadronic species before kinetic freeze-out; initial conditions based on the optical Glauber model, including a Monte-Carlo routine for event-by-event fluctuating initial conditions; a freeze-out procedure based on the Cooper-Frye prescription. The code is extensively validated against several test problems and results always appear accurate, as guaranteed by the combination of the conservative (shock-capturing) approach and the high-order methods employed. ECHO-QGP can be extended to include evolution of the electromagnetic fields coupled to the plasma.

L. Del Zanna; V. Chandra; G. Inghirami; V. Rolando; A. Beraudo; A. De Pace; G. Pagliara; A. Drago; F. Becattini

2013-05-30T23:59:59.000Z

419

The effects of early time laser drive on hydrodynamic instability growth in National Ignition Facility implosions  

SciTech Connect (OSTI)

Defects on inertial confinement fusion capsule surfaces can seed hydrodynamic instability growth and adversely affect capsule performance. The dynamics of shocks launched during the early period of x-ray driven National Ignition Facility (NIF) implosions determine whether perturbations will grow inward or outward at peak implosion velocity and final compression. In particular, the strength of the first shock, launched at the beginning of the laser pulse, plays an important role in determining Richtmyer-Meshkov (RM) oscillations on the ablation front. These surface oscillations can couple to the capsule interior through subsequent shocks before experiencing Rayleigh-Taylor (RT) growth. We compare radiation hydrodynamic simulations of NIF implosions to analytic theories of the ablative RM and RT instabilities to illustrate how early time laser strength can alter peak velocity growth. We develop a model that couples the RM and RT implosion phases and captures key features of full simulations. We also show how three key parameters can control the modal demarcation between outward and inward growth.

Peterson, J. L.; Clark, D. S.; Suter, L. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Masse, L. P. [CEA, DAM, DIF, 91297 Arpajon (France)

2014-09-15T23:59:59.000Z

420

$v_4$, $v_5$, $v_6$, $v_7$: nonlinear hydrodynamic response versus LHC data  

E-Print Network [OSTI]

Higher harmonics of anisotropic flow ($v_n$ with $n\\ge 4$) in heavy-ion collisions can be measured either with respect to their own plane, or with respect to a plane constructed using lower-order harmonics. We explain how such measurements are related to event-plane correlations. We show that CMS data on $v_4$ and $v_6$ are compatible with ATLAS data on event-plane correlations. If one assumes that higher harmonics are the superposition of non-linear and linear responses, then the linear and non-linear parts can be isolated under fairly general assumptions. By combining analyses of higher harmonics with analyses of $v_2$ and $v_3$, one can eliminate the uncertainty from initial conditions and define quantities that only involve nonlinear hydrodynamic response coefficients. Experimental data on $v_4$, $v_5$ and $v_6$ are in good agreement with hydrodynamic calculations. We argue that $v_7$ can be measured with respect to elliptic and triangular flow. We present predictions for $v_7$ versus centrality in Pb-Pb ...

Yan, Li

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Large area self-powered gamma ray detector. Phase 2, Development of a source position monitor for use on industrial radiographic units  

SciTech Connect (OSTI)

The purpose of this research was to develop a large area self-powered gamma detector (LASPGD) capable of detecting the movement of sealed radiation sources into and out of industrial radiographic units and to construct a prototype source position monitor (SPM) for these units utilizing the LASPGD. Prototype isotropic and directional LASPGDs, with solid and inert gas dielectrics, were developed and extensively tested using calibrated gamma sources (i.e., Cs-137, and Co-60). The sensitivities of the isotropic detectors, with inert gas dielectrics, were found to be approximately a factor of ten greater than those measured for the solid dielectric LASPGDs. Directionally sensitive self-powered detectors were found to exhibit a forward-to-back hemispherical sensitivity ratio of approximately 2 to 1. Industrial radiographic units containing Ir-192 sources with different activities were used to test the performance of the SPM. The SPM, which utilized a gas dielectric LASPGD, performed as designed. That is, the current generated in the LASPGD was converted to a voltage, amplified and used to control the on/off state of an incandescent lamp. The incandescent lamp, which functions as the source/out warning indicator, flashes at a rate of one flash per second when the source is in use (i.e. out of its shield).

LeVert, F.E. [K.E.M.P. Corp., Knoxville, TN (United States)

1994-01-01T23:59:59.000Z

422

ATCA/AXIe compatible board for fast control and data acquisition in nuclear fusion experiments  

Science Journals Connector (OSTI)

An in-house development of an Advanced Telecommunications Computing Architecture (ATCA) board for fast control and data acquisition, with Input/Output (IO) processing capability, is presented. The architecture, compatible with the ATCA (PICMG 3.4) and ATCA eXtensions for Instrumentation (AXIe) specifications, comprises a passive Rear Transition Module (RTM) for IO connectivity to ease hot-swap maintenance and simultaneously to increase cabling life cycle. The board complies with ITER Fast Plant System Controller (FPSC) guidelines for rear IO connectivity and redundancy, in order to provide high levels of reliability and availability to the control and data acquisition systems of nuclear fusion devices with long duration plasma discharges. Simultaneously digitized data from all Analog to Digital Converters (ADC) of the board can be filtered/decimated in a Field Programmable Gate Array (FPGA), decreasing data throughput, increasing resolution, and sent through Peripheral Component Interconnect (PCI) Express to multi-core processors in the ATCA shelf hub slots. Concurrently the multi-core processors can update the board Digital to Analog Converters (DAC) in real-time. Full-duplex point-to-point communication links between all FPGAs, of peer boards inside the shelf, allow the implementation of distributed algorithms and Multi-Input Multi-Output (MIMO) systems. Support for several timing and synchronization solutions is also provided. Some key features are onboard ADC or DAC modules with galvanic isolation, Xilinx Virtex 6 FPGA, standard Dual Data Rate (DDR) 3 SODIMM memory, standard CompactFLASH memory card, Intelligent Platform Management Controller (IPMC), two PCI Express x4 (generation 2) ATCA Fabric channels (dual-star topology), eleven Xilinx Aurora x1 (or other ATCA compatible communications protocol) ATCA fabric channels (full-mesh topology) and two Fast Ethernet (Precision Time Protocol – PTP IEEE1588-V2 and Lan eXtensions for Instrumentation – LXI compatible) ATCA base channels (dual-star topology).

A.J.N. Batista; C. Leong; V. Bexiga; A.P. Rodrigues; A. Combo; B.B. Carvalho; J. Fortunato; M. Correia; J.P. Teixeira; I.C. Teixeira; J. Sousa; B. Gonçalves; C.A.F. Varandas

2012-01-01T23:59:59.000Z

423

Optimization of Computational Performance and Accuracy in 3?D Transient CFD Model for CFB Hydrodynamics Predictions  

Science Journals Connector (OSTI)

This work aims to present a pure 3?D CFD model accurate and efficient for the simulation of a pilot scale CFB hydrodynamics. The accuracy of the model was investigated as a function of the numerical parameters in order to derive an optimum model setup with respect to computational cost. The necessity of the in depth examination of hydrodynamics emerges by the trend to scale up CFBCs. This scale up brings forward numerous design problems and uncertainties which can be successfully elucidated by CFD techniques. Deriving guidelines for setting a computational efficient model is important as the scale of the CFBs grows fast while computational power is limited. However the optimum efficiency matter has not been investigated thoroughly in the literature as authors were more concerned for their models accuracy and validity. The objective of this work is to investigate the parameters that influence the efficiency and accuracy of CFB computational fluid dynamics models find the optimum set of these parameters and thus establish this technique as a competitive method for the simulation and design of industrial large scale beds where the computational cost is otherwise prohibitive. During the tests that were performed in this work the influence of turbulence modeling approach time and space density and discretization schemes were investigated on a 1.2 MWth CFB test rig. Using Fourier analysis dominant frequencies were extracted in order to estimate the adequate time period for the averaging of all instantaneous values. The compliance with the experimental measurements was very good. The basic differences between the predictions that arose from the various model setups were pointed out and analyzed. The results showed that a model with high order space discretization schemes when applied on a coarse grid and averaging of the instantaneous scalar values for a 20 sec period adequately described the transient hydrodynamic behaviour of a pilot CFB while the computational cost was kept low. Flow patterns inside the bed such as the core?annulus flow and the transportation of clusters were at least qualitatively captured.

I. Rampidis; A. Nikolopoulos; N. Koukouzas; P. Grammelis; E. Kakaras

2007-01-01T23:59:59.000Z

424

Modifications of Carbonate Fracture Hydrodynamic Properties by CO{sub 2}-Acidified Brine Flow  

SciTech Connect (OSTI)

Acidic reactive flow in fractures is relevant in subsurface activities such as CO{sub 2} geological storage and hydraulic fracturing. Understanding reaction-induced changes in fracture hydrodynamic properties is essential for predicting subsurface flows such as leakage, injectability, and fluid production. In this study, x-ray computed tomography scans of a fractured carbonate caprock were used to create three dimensional reconstructions of the fracture before and after reaction with CO{sub 2}-acidified brine (Ellis et al., 2011, Greenhouse Gases: Sci. Technol., 1:248-260). As expected, mechanical apertures were found to increase substantially, doubling and even tripling in some places. However, the surface geometry evolved in complex ways including ‘comb-tooth’ structures created from preferential dissolution of calcite in transverse sedimentary bands, and the creation of degraded zones, i.e. porous calcite-depleted areas on reacted fracture surfaces. These geometric alterations resulted in increased fracture roughness, as measured by surface Z{sub 2} parameters and fractal dimensions D{sub f}. Computational fluid dynamics (CFD) simulations were conducted to quantify the changes in hydraulic aperture, fracture transmissivity and permeability. The results show that the effective hydraulic apertures are smaller than the mechanical apertures, and the changes in hydraulic apertures are nonlinear. Overestimation of flow rate by a factor of two or more would be introduced if fracture hydrodynamic properties were based on mechanical apertures, or if hydraulic aperture is assumed to change proportionally with mechanical aperture. The differences can be attributed, in part, to the increase in roughness after reaction, and is likely affected by contiguous transverse sedimentary features. Hydraulic apertures estimated by the 1D statistical model and 2D local cubic law (LCL) model are consistently larger than those calculated from the CFD simulations. In addition, a novel ternary segmentation method was devised to handle the degraded zones, allowing for a bounding analysis of the effects on hydraulic properties. We found that the degraded zones account for less than 15% of the fracture volume, but cover 70% to 80% of the fracture surface. When the degraded zones are treated as part of the fracture, the fracture transmissivities are two to four times larger because the fracture surfaces after reaction are not as rough as they would be if one considers the degraded zone as part of the rock. Therefore, while degraded zones created during geochemical reactions may not significantly increase mechanical aperture, this type of feature cannot be ignored and should be treated with prudence when predicting fracture hydrodynamic properties.

Deng, Hang; Ellis, Brian R.; Peters, Catherine A.; Fitts, Jeffrey P.; Crandall, Dustin; Bromhal, Grant S.

2013-08-01T23:59:59.000Z

425

Use of remote sensing data to enhance the performance of a hydrodynamic simulation of a partially frozen power plant  

E-Print Network [OSTI]

on the overall efficiency of a power plant. The ability to monitor a cooling pond using thermal remote sensing of a power plant cooling pond in the presence of ice and snow. Keywords: thermal infrared, hydrodynamic with the objective of improving our ability to understand and simulate the thermodynamics and dynamics of power plant

Salvaggio, Carl

426

Lattice Boltzmann open boundaries for hydrodynamic models A.F. Bennett a,*, J.R. Taylor b  

E-Print Network [OSTI]

Lattice Boltzmann open boundaries for hydrodynamic models A.F. Bennett a,*, J.R. Taylor b , B posed in every respect. Inserting lattice Boltzmann kinetics between hydrostatic boundary data-posedness; Lattice Boltzmann 1. Introduction It is ironic that the introduction of digital computing into fluid

Cambridge, University of

427

3D Lattice Boltzmann Magneto-hydrodynamics Sam Williams1,2, Jonathan Carter2, Leonid Oliker2,  

E-Print Network [OSTI]

1 3D Lattice Boltzmann Magneto-hydrodynamics (LBMHD3D) Sam Williams1,2, Jonathan Carter2, Leonid;5 Quick Introduction to Lattice Methods and LBMHD #12;6 Lattice Methods · Lattice Boltzmann models Lab samw@cs.berkeley.edu October 26, 2006 #12;2 · Previous Cell Work · Lattice Methods & LBMHD

428

Investigation of the hydrodynamics of flash floods in ephemeral channels: Scaling analysis and simulation using a shock-capturing  

E-Print Network [OSTI]

U N C O R R EC TED PR O O F Investigation of the hydrodynamics of flash floods in ephemeral channels: Scaling analysis and simulation using a shock-capturing flow model incorporating the effects; revised 29 August 2005; accepted 11 September 2005 Abstract Flow and infiltration during flash floods

429

THE JOURNAL OF EXPERIMENTAL ZOOLOGY 258164-173 (1991) Hydrodynamics of the Feet of Fish-Catching Bats  

E-Print Network [OSTI]

THE JOURNAL OF EXPERIMENTAL ZOOLOGY 258164-173 (1991) Hydrodynamics of the Feet of Fish-Catching Bats: Influence of the Water Surface on Drag and Morphological Design FRANK E. FISH, BRAD R. BLOOD and Pizonyx uiuesi, display similar hind foot mor- phologies specialized for their fish-catching habits

Fish, Frank

430

Hydrodynamics of Hemostasis in Sickle-Cell Disease S. I. A. Cohen1,* and L. Mahadevan1,2,  

E-Print Network [OSTI]

Hydrodynamics of Hemostasis in Sickle-Cell Disease S. I. A. Cohen1,* and L. Mahadevan1,2, 1 School flow in sickle-cell disease, is a complex dynamical process spanning multiple time and length scales. Motivated by recent ex vivo microfluidic measurements of hemostasis using blood from sickle-cell patients

Mahadevan, L.

431

MaGICC-WDM: the effects of warm dark matter in hydrodynamical simulations of disc galaxy formation  

Science Journals Connector (OSTI)

......the smoothed particle hydrodynamics code gasoline (Wadsley, Stadel Quinn 2004). It includes...those properties for the WDM1 case, in runs performed with different stellar feedback...orbits. While the satellite of g1536 falls straight into the centre of the host galaxy the......

Jakob Herpich; Gregory S. Stinson; Andrea V. Macciò; Chris Brook; James Wadsley; Hugh M. P. Couchman; Tom Quinn

2014-01-01T23:59:59.000Z

432

Galactic scale gas flows in colliding galaxies: 3-Dimensional, N-body/hydrodynamics experiments  

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

Galactic Scale Gas Flows in Colliding Galaxies: Galactic Scale Gas Flows in Colliding Galaxies: a-Dimensional, N-bodyjHydrodynamics Experiments Susan A. Lamb* NORDITA and Neils Bohr Institute, Blegdamsvej 17, DK-2100, Kpbenhaven 0, Danmark. Richard A. Gerber University of Illinois at Urbana-Champaign, Departments of Physics and Astronomy, 1110 W. Green Street, Urbana, IL 61801, U.S.A. and Dinshaw S. Balsara t Johns Hopkins University, Department of Physics and Astronomy, Homewood Campu.s, Baltimore, MD 21218, U.S.A. Abstract. We present some result.s from three dimensional computer simulations of collisions between models of equal mass gaJaxies, one of which is a rotating, disk galaxy containing both gas and stars and the other is an elliptical contaiuing stars only. We use fully self consistent models in which the

433

Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors  

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

5021 5021 August 2009 Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors D. Sale University of Tennessee J. Jonkman and W. Musial National Renewable Energy Laboratory Presented at the ASME 28 th International Conference on Ocean, Offshore, and Arctic Engineering Honolulu, Hawaii May 31-June 5, 2009 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (ASE), a contractor of the US Government under Contract No. DE-AC36-08-GO28308. Accordingly, the US Government and ASE retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

434

Hydrodynamic Scaling Analysis of Nuclear Fusion driven by ultra-intense laser-plasma interactions  

E-Print Network [OSTI]

We discuss scaling laws of fusion yields generated by laser-plasma interactions. The yields are found to scale as a function of the laser power. The origin of the scaling law in the laser driven fusion yield is derived in terms of hydrodynamic scaling. We point out that the scaling properties can be attributed to the laser power dependence of three terms: the reaction rate, the density of the plasma and the projected range of the plasma particle in the target medium. The resulting scaling relations have a predictive power that enables estimating the fusion yield for a nuclear reaction which has not been investigated by means of the laser accelerated ion beams.

Sachie Kimura; Aldo Bonasera

2011-09-23T23:59:59.000Z

435

N=2 supersymmetric extension of a hydrodynamic system in Riemann invariants  

SciTech Connect (OSTI)

In this paper, we formulate an N=2 supersymmetric extension of a hydrodynamic-type system involving Riemann invariants. The supersymmetric version is constructed by means of a superspace and superfield formalism, using bosonic superfields, and consists of a system of partial differential equations involving both bosonic and fermionic variables. We make use of group-theoretical methods in order to analyze the extended model algebraically. Specifically, we calculate a Lie superalgebra of symmetries of our supersymmetric model and make use of a general classification method to classify the one-dimensional subalgebras into conjugacy classes. As a result we obtain a set of 401 one-dimensional nonequivalent subalgebras. For selected subalgebras, we use the symmetry reduction method applied to Grassmann-valued equations in order to determine analytic exact solutions of our supersymmetric model. These solutions include traveling waves, bumps, kinks, double-periodic solutions, and solutions involving exponentials and radicals.

Grundland, A. M. [Centre de Recherches Mathematiques, Universite de Montreal, C.P. 6128, Succ. Centre-ville, Montreal, Quebec H3C 3J7 (Canada); Universite du Quebec, Trois-Rivieres, C.P. 500, Quebec G9A 5H7 (Canada); Hariton, A. J. [Centre de Recherches Mathematiques, Universite de Montreal, C.P. 6128, Succ. Centre-ville, Montreal, Quebec H3C 3J7 (Canada)

2009-07-15T23:59:59.000Z

436

Hydrodynamic transport coefficients for the non-conformal quark-gluon plasma from holography  

E-Print Network [OSTI]

In this paper we obtain holographic formulas for the transport coefficients $\\kappa$ and $\\tau_\\pi$ present in the second-order derivative expansion of relativistic hydrodynamics in curved spacetime associated with a non-conformal strongly coupled plasma described holographically by an Einstein+Scalar action in the bulk. We compute these coefficients as functions of the temperature in a bottom-up non-conformal model that is tuned to reproduce lattice QCD thermodynamics at zero baryon chemical potential. We directly compute, besides the speed of sound, 6 other transport coefficients that appear at second-order in the derivative expansion. We also give an estimate for the temperature dependence of 11 other transport coefficients taking into account the simplest contribution from non-conformal effects that appear near the QCD crossover phase transition. Using these results, we construct an Israel-Stewart-like theory in flat spacetime containing 13 of these 17 transport coefficients that should be suitable for ph...

Finazzo, Stefano I; Marrochio, Hugo; Noronha, Jorge

2014-01-01T23:59:59.000Z

437

Development of a Hydrodynamic and Transport model of Bellingham Bay in Support of Nearshore Habitat Restoration  

SciTech Connect (OSTI)

In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratory’s high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric light detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of root mean square error values for surface elevation, velocity, temperature, and salinity time series are 0.11 m, 0.10 m/s, 1.28oC, and 1.91 ppt, respectively. The model was able to reproduce the salinity and temperature stratifications inside Bellingham Bay. Wetting and drying processes in tidal flats in Bellingham Bay, Samish Bay, and Padilla Bay were also successfully simulated. Both model results and observed data indicated that water surface elevations inside Bellingham Bay are highly correlated to tides. Circulation inside the bay is weak and complex and is affected by various forcing mechanisms, including tides, winds, freshwater inflows, and other local forcing factors. The Bellingham Bay model solution was successfully linked to the NOAA oil spill trajectory simulation model “General NOAA Operational Modeling Environment (GNOME).” Overall, the Bellingham Bay model has been calibrated reasonably well and can be used to provide detailed hydrodynamic information in the bay and adjacent water bodies. While there is room for further improvement with more available data, the calibrated hydrodynamic model provides useful hydrodynamic information in Bellingham Bay and can be used to support sediment transport and water quality modeling as well as assist in the design of nearshore restoration scenarios.

Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang

2010-04-22T23:59:59.000Z

438

Redesign of turbine-pump impeller and diffuser using hydrodynamic design techniques. Final report  

SciTech Connect (OSTI)

It is indicated that in 1976 the average operating efficiency of well irrigation pumps in the US, including losses in the column pipe and line shaft, was 55.5%, but information is presented to show that losses in a pumping system can be reduced and that it is possible to reach a goal of 82% system efficiency. Hydrodynamic design methods which are used to analyze and modify a commercially available pump are presented. The results of tests with the pump are presented for which delivery losses were reduced by means of a packer at the pump and for which line shaft losses were reduced by means of a high strength line shaft. Methods of designing pumps that have a broader high efficiency range are explored, and a design approach for doing so is presented. The method was not evaluated experimentally. (MCW)

Hamrick, J.T.

1980-04-01T23:59:59.000Z

439

Flow-field dynamics during droplet formation by dripping in hydrodynamic-focusing microfluidics  

Science Journals Connector (OSTI)

Using microscopic particle image velocimetry, we examine the flow field around an oil droplet as it is formed by hydrodynamic focusing in an aqueous solution using a pressure-driven cross-channel microfluidic device. By detecting the temporal dependence of the instantaneous flow fields of the continuous phase in the dripping regime, we show that shear is not the primary mechanism that initiates droplet formation in our low flow rate and moderate capillary number experimental conditions. Instead, the advancing finger of oil partially and temporarily plugs the outlet channel, creating a pressure difference that builds up and is released when water from the side channels pushes the tip of the finger into the outlet channel, thereby facilitating the birth of the droplet by interfacial pinch-off that is primarily initiated by an extensional flow.

D. Funfschilling; H. Debas; H.-Z. Li; T. G. Mason

2009-07-06T23:59:59.000Z

440

Exact solution of the 1D Riemann problem in Newtonian and relativistic hydrodynamics  

E-Print Network [OSTI]

Some of the most interesting scenarios that can be studied in astrophysics, contain fluids and plasma moving under the influence of strong gravitational fields. To study these problems it is required to implement numerical algorithms robust enough to deal with the equations describing such scenarios, which usually involve hydrodynamical shocks. It is traditional that the first problem a student willing to develop research in this area is to numerically solve the one dimensional Riemann problem, both Newtonian and relativistic. Even a more basic requirement is the construction of the exact solution to this problem in order to verify that the numerical implementations are correct. We describe in this paper the construction of the exact solution and a detailed procedure of its implementation.

F. D. Lora-Clavijo; J. P. Cruz-Perez; F. S. Guzman; J. A. Gonzalez

2013-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Single molecule study of DNA collision with elliptical nanoposts conveyed by hydrodynamics  

E-Print Network [OSTI]

Periodic arrays of micro- or nano-pillars constitute solid state matrices with excellent properties for DNA size separation. Nanofabrication technologies offer many solutions to tailor the geometry of obstacle arrays, yet most studies have been conducted with cylinders arranged in hexagonal lattices. In this report, we investigate the dynamics of single DNA collision with elliptical nanoposts using hydrodynamic actuation. Our data shows that the asymmetry of the obstacles has minor effect on unhooking dynamics, and thus confirms recent predictions obtained by Brownian dynamics simulations. In addition, we show that the disengagement dynamics are correctly predicted by models of electrophoresis, and propose that this consistency is associated to the confinement in slit-like channels. We finally conclude that elliptical posts are expected to marginally improve the performances of separation devices.

Viero, Yannick; Fouet, Marc; Bancaud, Aurélien

2014-01-01T23:59:59.000Z

442

Soot blower optimization; Part 1: Fundamental hydrodynamics of a soot blower nozzle and jet  

SciTech Connect (OSTI)

The fundamental hydrodynamics of soot blower nozzles and jets are examined. For currently available nozzles, a substantial fraction of the energy available in the steam jet is dissipated as the steam passes through a shock wave only a few jet diameters beyond the nozzle outlet. Only a small fraction of the initial energy is delivered to the heat-transfer surface for cleaning. Efforts to increase the delivered energy by raising the upstream steam pressure above the design condition produces a larger shock wave and only a small increase in delivered energy. Nozzle design should be changed to permit full expansion of the steam before it leaves the nozzle. This would eliminate the shock wave and substantially improve soot blower performance.

Jameel, M.I.; Cormack, D.E.; Tran, H. (Univ. of Toronto, Ontario (Canada). Dept. of Chemical Engineering and Applied Chemistry); Moskal, T.E. (Diamond Power Specialty Corp., Lancaster, OH (United States))

1994-05-01T23:59:59.000Z

443

Radiative Hydrodynamic Models of the Optical and Ultraviolet Emission from Solar Flares  

E-Print Network [OSTI]

We report on radiative hydrodynamic simulations of moderate and strong solar flares. The flares were simulated by calculating the atmospheric response to a beam of non-thermal electrons injected at the apex of a one-dimensional closed coronal loop, and include heating from thermal soft X-ray, extreme ultraviolet and ultraviolet (XEUV) emission. The equations of radiative transfer and statistical equilibrium were treated in non-LTE and solved for numerous transitions of hydrogen, helium, and Ca II allowing the calculation of detailed line profiles and continuum emission. This work improves upon previous simulations by incorporating more realistic non-thermal electron beam models and includes a more rigorous model of thermal XEUV heating. We find XEUV backwarming contributes less than 10% of the heating, even in strong flares. The simulations show elevated coronal and transition region densities resulting in dramatic increases in line and continuum emission in both the UV and optical regions. The optical continuum reaches a peak increase of several percent which is consistent with enhancements observed in solar white light flares. For a moderate flare (~M-class), the dynamics are characterized by a long gentle phase of near balance between flare heating and radiative cooling, followed by an explosive phase with beam heating dominating over cooling and characterized by strong hydrodynamic waves. For a strong flare (~X-class), the gentle phase is much shorter, and we speculate that for even stronger flares the gentle phase may be essentially non-existent. During the explosive phase, synthetic profiles for lines formed in the upper chromosphere and transition region show blue shifts corresponding to a plasma velocity of ~120 km/s, and lines formed in the lower chromosphere show red shifts of ~40 km/s.

J. C. Allred; S. L. Hawley; W. P. Abbett; M. Carlsson

2005-07-13T23:59:59.000Z

444

NMR imaging and hydrodynamic analysis of neutrally buoyant non-Newtonian slurry flows  

SciTech Connect (OSTI)

The flow of solids loaded suspension in cylindrical pipes has been the object of intense experimental and theoretical investigations in recent years. These types of flows are of great interest in chemical engineering because of their important use in many industrial manufacturing processes. Such flows are for example encountered in the manufacture of solid-rocket propellants, advanced ceramics, reinforced polymer composites, in heterogenous catalytic reactors, and in the pipeline transport of liquid-solids suspensions. In most cases, the suspension microstructure and the degree of solids dispersion greatly affect the final performance of the manufactured product. For example, solid propellant pellets need to be extremely-well dispersed in gel matrices for use as rocket engine solid fuels. The homogeneity of pellet dispersion is critical to allow good uniformity of the burn rate, which in turn affects the final mechanical performance of the engine. Today`s manufacturing of such fuels uses continuous flow processes rather than batch processes. Unfortunately, the hydrodynamics of such flow processes is poorly understood and is difficult to assess because it requires the simultaneous measurements of liquid/solids phase velocities and volume fractions. Due to the recent development in pulsed Fourier Transform NMR imaging, NMR imaging is now becoming a powerful technique for the non intrusive investigation of multi-phase flows. This paper reports and exposes a state-of-the-art experimental and theoretical methodology that can be used to study such flows. The hydrodynamic model developed for this study is a two-phase flow shear thinning model with standard constitutive fluid/solids interphase drag and solids compaction stresses. this model shows good agreement with experimental data and the limitations of this model are discussed.

Bouillard, J.X. [Argonne National Lab., IL (United States); Sinton, S.W. [Lockheed Missiles and Space Co., Palo Alto, CA (United States). Research Lab.

1995-02-01T23:59:59.000Z

445

Method and device for determining the position of a cutting tool relative to the rotational axis of a spindle-mounted workpiece  

DOE Patents [OSTI]

The present invention is directed to a method and device for determining the location of a cutting tool with respect to the rotational axis of a spindle-mounted workpiece. A vacuum cup supporting a machinable sacrificial pin is secured to the workpiece at a location where the pin will project along and encompass the rotational axis of the workpiece. The pin is then machined into a cylinder. The position of the surface of the cutting tool contacting the machine cylinder is spaced from the rotational axis of the workpiece a distance equal to the radius of the cylinder.

Williams, R.R.

1980-09-03T23:59:59.000Z

446

Prenatal Food Restriction Induces a Hypothalamic-Pituitary-Adrenocortical Axis-associated Neuroendocrine Metabolic Programmed Alteration in Adult Offspring Rats  

Science Journals Connector (OSTI)

Background and Aims Intrauterine growth restriction produces susceptibility to adult metabolic syndrome, which may be caused by the permanent alteration of the hypothalamic-pituitary-adrenocortical (HPA) axis. We aimed to verify that HPA axis-associated neuroendocrine metabolic programming is altered in food-restricted (FR) offspring. Methods Maternal rats were fed a restricted diet from gestational day 11 until full-term delivery, all pups were fed a high-fat diet after weaning and exposed to unpredictable chronic stress (UCS) during postnatal weeks 17–20. Results Serum levels of adrenocorticotrophic hormone and corticosterone in adult offspring of the prenatal FR group were lower than the control (CN) rats before UCS but increased significantly after UCS. Serum glucose levels in the FR group were normal before UCS but increased after UCS. Serum insulin levels were significantly decreased in FR males but showed a slight increase in FR females before UCS; however, insulin levels decreased significantly in the FR male and female rats after UCS. Before UCS, serum lipid levels were higher in the FR males but were normal in the FR females; after UCS, FR males had a slight decrease and FR females had an increasing trend in serum lipids levels. Lipid droplets in the hypothalamus, pituitary gland, and livers of the FR group indicated steatosis. Conclusions These results suggest that prenatal food restriction alters HPA axis-associated neuroendocrine metabolism in adult offspring fed a high-fat diet, which may originate from the intrauterine programming and increase the susceptibility to adult metabolic diseases.

Li Zhang; Dan Xu; Benjian Zhang; Yansong Liu; Fenglong Chu; Yuming Guo; Jun Gong; Xun Zheng; Liaobin Chen; Hui Wang

2013-01-01T23:59:59.000Z

447

Raindrop axis ratios, fall velocities and size distribution over Sumatra from 2D-Video Disdrometer measurement  

Science Journals Connector (OSTI)

Raindrop axis ratio, falling velocity and size distribution are important in broad list of applications. However, they are not frequently observed in the equatorial region. This paper elucidated the characteristics of raindrop axis ratio, falling velocity and size distribution based on 2D-Video Disdrometer (2DVD) data that have been collected in the equatorial Indonesia, particularly at Kototabang (hereafter called KT), west Sumatra, Indonesia (0.20°S, 100.32°E, 864 m above sea level). A comprehensive follow-up of the previous study on the natural variability of raindrop size distributions (DSDs) is presented. Precipitation was classified through 1.3-GHz wind profiler observation. The dependence of raindrop falling velocity and axis ratio on rainfall type was not clearly observed. Overall, measured raindrop fall velocities were in good agreement with Gunn–Kinzer's data. Raindrop axis ratio at KT was more spherical than that of artificial rain and equilibrium model, and close to the values reported in the turbulent high shear zone of surface layer which can be partially due to the effect of the instrument errors (e.g., location and container shape). Of some natural variations of DSD investigated, the dependence of DSD on rainfall rate and rainfall type as well as diurnal variation was clearly visible. A striking contrast between the stratiform and convective rains is that the size distributions from the stratiform (convective) rains tend to narrow (broaden) with increasing rainfall rates. For rainfall rate R < 10 mm/h, the size distribution of stratiform was broader than that of convective. On the other hand, at higher rainfall rate more large-sized drops were found in convective rain. During the convective rain, very large-sized drops were found mainly at the very start of rain event while for the stratiform they were found to be associated with a strong bright band. In diurnal basis, the \\{DSDs\\} in the morning hours were narrower than those in the evening which was indicated by smaller Dm values in the morning hours than their counterparts in the evening. Rainfall type dependence and diurnal variation of DSD lead to significant variation of Z–R relations so that they must be considered to increase the accuracy of Z–R conversion from weather radar in this region. Consistent with the previous study, lack of seasonal DSD variability was also found in this work that would be due to significant local convective and orographic effect at this region throughout the year. However, Dm values in our result were larger than the typical orographic DSD.

Marzuki; Walter L. Randeu; Toshiaki Kozu; Toyoshi Shimomai; Hiroyuki Hashiguchi; Michael Schönhuber

2013-01-01T23:59:59.000Z

448

Numerical Simulation of Hydrodynamics of a Heavy Liquid Drop Covered by Vapor Film in a Water Pool  

SciTech Connect (OSTI)

A numerical study on the hydrodynamics of a droplet covered by vapor film in water pool is carried out. Two level set functions are used as to implicitly capture the interfaces among three immiscible fluids (melt-drop, vapor and coolant). This approach leaves only one set of conservation equations for the three phases. A high-order Navier-Stokes solver, called Cubic-Interpolated Pseudo-Particle (CIP) algorithm, is employed in combination with level set approach, which allows large density ratios (up to 1000), surface tension and jump in viscosity. By this calculation, the hydrodynamic behavior of a melt droplet falling into a volatile coolant is simulated, which is of great significance to reveal the mechanism of steam explosion during a hypothetical severe reactor accident. (authors)

Ma, W.M.; Yang, Z.L.; Giri, A.; Sehgal, B.R. [Royal Institute of Technology (KTH), Drottning Kristinas vaeg 33 A, 100 44, Stockholm (Sweden)

2002-07-01T23:59:59.000Z

449

Design of a free-running, 1/30th Froude scaled model destroyer for in-situ hydrodynamic flow visualization  

E-Print Network [OSTI]

Hydrodynamic flow visualization techniques of scaled hull forms and propellers are typically limited to isolating certain operating conditions in a tow tank, circulation tunnel, or large maneuvering basin. Although cost ...

Cope, David M. (David Michael)

2012-01-01T23:59:59.000Z

450

Influence of Water Allocation and Freshwater Inflow on Oyster Production: A Hydrodynamic–Oyster Population Model for Galveston Bay, Texas, USA  

Science Journals Connector (OSTI)

A hydrodynamic–oyster population model was developed to assess the effect of changes in freshwater inflow on oyster populations in Galveston Bay, Texas, USA. The population model includes the...Perkinsus marinus,

ERIC N. POWELL; JOHN M. KLINCK; EILEEN E. HOFMANN…

2003-01-01T23:59:59.000Z

451

Two-and three-dimensional modeling and optimization applied to the design of a fast hydrodynamic focusing microfluidic mixer for protein folding  

E-Print Network [OSTI]

focusing microfluidic mixer for protein folding Benjamin Ivorra, Juana L. Redondo, Juan G. Santiago, Pilar of a fast hydrodynamic focusing microfluidic mixer for protein folding Benjamin Ivorra,1,a) Juana L. Redondo

Santiago, Juan G.

452

Depositional environment and hydrodynamic flow in Guadalupian Cherry Canyon sandstone, West Ford and West Geraldine fields, Delaware Basin, Texas  

E-Print Network [OSTI]

and entrapment of hydrocarbons. Delaware Mountain Group sediments are currently generating oil. Decementation enhances the reservoir by the formation of secondary porosity. The reservoir sandstones have an aver age porosity of 26$ and an aver age permeability... of 24 md. Oil accumulates in stratigraphic traps located along the updip meander loops of tur bidite channels. A tilted oil/water contact in West Ford and West Ger aldine fields indicates that hydrodynamic flow is pr esent. Heads calculated...

Linn, Anne Marie

2012-06-07T23:59:59.000Z

453

The hydrodynamics of relict cosmological H?i i regions: impact of the IGM  

Science Journals Connector (OSTI)

Discrete sources of photoionizing radiation present at the time the intergalactic medium is largely neutral will create expanding H?i i regions. A source which turns off or dims quickly enough will not be able to maintain the advance of its ionization front indefinitely. The high pressure of the relict H?i i region will then drive a shock into the cold neutral ambient medium. We discuss the hydrodynamical evolution of relict cosmological H?i i regions generated at redshifts z?5–15. A thin shell of shocked material develops around the H?i i region. The peculiar velocity of the shell is typically 10–20 km s? 1. The dense shell may cool and fragment into objects with baryonic masses as high as 106–108 M ? and column densities of order 101 9 cm? 2. These values are independent of the nature of the photoionizing source. They are set only by the density of the IGM the sound speed of 104 K gas and the age of the shell. The shock propagation ceases once the filling factor of the H?i i regions reaches unity and the IGM is photoionized. The clouds formed may account for the Ly? forest seen in the spectra of high redshift QSOs. Gravitationally bound fragments may be candidates for blue?excess galaxies at high redshift.

Avery Meiksin; Piero Madau

1991-01-01T23:59:59.000Z

454

Three-dimensional hydrodynamic simulations of asymmetric pulsar wind bow shocks  

E-Print Network [OSTI]

We present three-dimensional, nonrelativistic, hydrodynamic simulations of bow shocks in pulsar wind nebulae. The simulations are performed for a range of initial and boundary conditions to quantify the degree of asymmetry produced by latitudinal variations in the momentum flux of the pulsar wind, radiative cooling in the postshock flow, and density gradients in the interstellar medium (ISM). We find that the bow shock is stable even when travelling through a strong ISM gradient. We demonstrate how the shape of the bow shock changes when the pulsar encounters density variations in the ISM. We show that a density wall can account for the peculiar bow shock shapes of the nebulae around PSR J2124-3358 and PSR B0740-28. A wall produces kinks in the shock, whereas a smooth ISM density gradient tilts the shock. We conclude that the anisotropy of the wind momentum flux alone cannot explain the observed bow shock morphologies but it is instead necessary to take into account external effects. We show that the analytic (single layer, thin shell) solution is a good approximation when the momentum flux is anisotropic, fails for a steep ISM density gradient, and ap- proaches the numerical solution for efficient cooling. We provide analytic expressions for the latitudinal dependence of a vacuum-dipole wind and the associated shock shape, and compare the results to a split-monopole wind. We find that we are unable to distinguish between these two wind models purely from the bow shock morphology.

M. Vigelius; A. Melatos; S. Chatterjee; B. M. Gaensler; P. Ghavamian

2006-10-16T23:59:59.000Z

455

On the relevance of subcritical hydrodynamic turbulence to accretion disk transport  

E-Print Network [OSTI]

Hydrodynamic unstratified keplerian flows are known to be linearly stable at all Reynolds numbers, but may nevertheless become turbulent through nonlinear mechanisms. However, in the last ten years, conflicting points of view have appeared on this issue. We have revisited the problem through numerical simulations in the shearing sheet limit. It turns out that the effect of the Coriolis force in stabilizing the flow depends on whether the flow is cyclonic (cooperating shear and rotation vorticities) or anticyclonic (competing shear and rotation vorticities); keplerian flows are anticyclonic. We have obtained the following results: i/ The Coriolis force does not quench turbulence in subcritical flows; ii/ The resolution demand, when moving away from the marginal stability boundary, is much more severe for anticyclonic flows than for cyclonic ones. Presently available computer resources do not allow numerical codes to reach the keplerian regime. iii/ The efficiency of turbulent transport is directly correlated to the Reynolds number of transition to turbulence $Rg$, in such a way that the Shakura-Sunyaev parameter $\\alpha\\sim 1/Rg$. iv/ Even the most optimistic extrapolations of our numerical data show that subcritical turbulent transport would be too inefficient in keplerian flows by several orders of magnitude for astrophysical purposes. v/ Our results suggest that the data obtained for keplerian-like flows in a Taylor-Couette settings are largely affected by secondary flows, such as Ekman circulation.

G. Lesur; P-Y. Longaretti

2005-09-19T23:59:59.000Z

456

Hydrodynamic flow in heavy-ion collisions with large hadronic viscosity  

SciTech Connect (OSTI)

Using the (2+1)-dimensional viscous hydrodynamic code vish2+1 with a temperature-dependent specific shear viscosity ({eta}/s)(T), we present a detailed study of the influence of a large hadronic shear viscosity and its corresponding relaxation time {tau}{sub {pi}} on the transverse momentum spectra and elliptic flow of hadrons produced in 200A GeV Au+Au collisions. Although theory, in principle, predicts a well-defined relation {tau}{sub {pi}T}={kappa}(T)x({eta}/s)(T), the precise form of {kappa}(T) for the matter created in relativistic heavy-ion collisions is not known. For the popular choice {kappa}=3 the hadron spectra are found to be insensitive to a significant rise of {eta}/s in the hadronic stage, whereas their differential elliptic flow v{sub 2}(p{sub T}) is strongly suppressed by large hadronic viscosity. The large viscous effects on v{sub 2} are strongly reduced if (as theoretically expected) {kappa}(T) is allowed to grow with decreasing temperature in the hadronic stage. This implies that, until reliable calculations of {kappa}(T) become available, an extraction of the hadronic shear viscosity from a comparison between vish2+1 and a microscopic hadron cascade or experimental data requires a simultaneous fit of ({eta}/s)(T) and {kappa}(T).

Shen Chun; Heinz, Ulrich [Department of Physics, Ohio State University, Columbus, Ohio 43210-1117 (United States)

2011-04-15T23:59:59.000Z

457

Hydrodynamic modeling of deconfinement phase transition in heavy-ion collisions at NICA-FAIR energies  

E-Print Network [OSTI]

We use (3+1) dimensional ideal hydrodynamics to describe the space-time evolution of strongly interacting matter created in Au+Au and Pb+Pb collisions. The model is applied for the domain of bombarding energies 1-160 AGeV which includes future NICA and FAIR experiments. Two equations of state are used: the first one corresponding to resonance hadron gas and the second one including the deconfinement phase transition. The initial state is represented by two Lorentz-boosted nuclei. Dynamical trajectories of matter in the central box of the system are analyzed. They can be well represented by a fast shock-wave compression followed by a relatively slow isentropic expansion. The parameters of collective flows and hadronic spectra are calculated under assumption of the isochronous freeze-out. It is shown that the deconfinement phase transition leads to broadening of proton rapidity distributions, increase of elliptic flows and formation of the directed antiflow in the central rapidity region. These effects are most pronounced at bombarding energies around 10 AGeV, when the system spends the longest time in the mixed phase. From the comparison with three-fluid calculations we conclude that the transparency effects are not so important in central collisions at NICA-FAIR energies (below 30 AGeV).

A. V. Merdeev; L. M. Satarov; I. N. Mishustin

2011-03-21T23:59:59.000Z

458

Lattice Boltzmann method for relativistic hydrodynamics: Issues on conservation law of particle number and discontinuities  

E-Print Network [OSTI]

In this paper, we aim to address several important issues about the recently developed lattice Boltzmann (LB) model for relativistic hydrodynamics [M. Mendoza et al., Phys. Rev. Lett. 105, 014502 (2010); Phys. Rev. D 82, 105008 (2010)]. First, we study the conservation law of particle number in the relativistic LB model. Through the Chapman-Enskog analysis, it is shown that in the relativistic LB model the conservation equation of particle number is a convection-diffusion equation rather than a continuity equation, which makes the evolution of particle number dependent on the relaxation time. Furthermore, we investigate the origin of the discontinuities appeared in the relativistic problems with high viscosities, which were reported in a recent study [D. Hupp et al., Phys. Rev. D 84, 125015 (2011)]. A multiple-relaxation-time (MRT) relativistic LB model is presented to examine the influences of different relaxation times on the discontinuities. Numerical experiments show the discontinuities can be eliminated by setting the relaxation time $\\tau_e$ (related to the bulk viscosity) to be sufficiently smaller than the relaxation time $\\tau_v$ (related to the shear viscosity). Meanwhile, it is found that the relaxation time $\\tau_\\varepsilon$, which has no effect on the conservation equations at the Navier-Stokes level, will affect the numerical accuracy of the relativistic LB model. Moreover, the accuracy of the relativistic LB model for simulating moderately relativistic problems is also investigated.

Q. Li; K. H. Luo; X. J. Li

2012-11-14T23:59:59.000Z

459

Nonlinear effects on hydrodynamic pressure field caused by ship moving at supercritical speed in shallow water  

Science Journals Connector (OSTI)

Abstract Based on the shallow-water wave potential flow theory and the assumption of a slender ship, a mathematical model has been established for the pressure field caused by ship moving at supercritical speed in shallow water, with nonlinear and dispersive effects taken into account. The finite difference method is used for the numerical calculation of the ship hydrodynamic pressure field (SHPF), with the central and upwind difference schemes as a combination for the second derivative of the nonlinear term. And the artificial viscous terms are added in the hull and upstream boundary conditions to ensure the stability of solving the nonlinear equation. The comparison between the calculated results and the experimental results shows that both the mathematical model and the calculation method are effective and feasible. The analysis of the nonlinear effects of different-depth water, different depth Froude number and different-width channel on SHPF indicates that the closer to the critical speed the ship in sailing, the narrower the channel becomes, the greater the nonlinear effects on SHPF are.

Hui Deng; Zhi-hong Zhang; Ju-bin Liu; Jian-nong Gu

2014-01-01T23:59:59.000Z

460

Solar Flare Chromospheric Line Emission: Comparison Between IBIS High-resolution Observations and Radiative Hydrodynamic Simulations  

E-Print Network [OSTI]

Solar flares involve impulsive energy release, which results in enhanced radiation in a broad spectral and at a wide height range. In particular, line emission from the chromosphere (lower atmosphere) can provide critical diagnostics of plasma heating processes. Thus, a direct comparison between high-resolution spectroscopic observations and advanced numerical modeling results can be extremely valuable, but has not been attempted so far. We present in this paper such a self-consistent investigation of an M3.0 flare observed by the Dunn Solar Telescope's (DST) Interferometric Bi-dimensional Spectrometer (IBIS) on 2011 September 24 that we have modeled with the radiative hydrodynamic code RADYN (Carlsson & Stein 1992, 1997; Abbett & Hawley 1999; Allred et al. 2005). We obtained images and spectra of the flaring region with IBIS in H$\\alpha$ 6563 \\AA\\ and Ca II 8542 \\AA, and with the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) in X-rays. The latter was used to infer the non-thermal elect...

da Costa, Fatima Rubio; Petrosian, Vahé; Dalda, Alberto Sainz; Liu, Wei

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axis radiographic hydrodynamic" 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

Transient hydrodynamic, heat and mass transfer in a salinity gradient solar pond: A numerical study  

Science Journals Connector (OSTI)

Abstract The impoverishment of our planet in non-renewable energies has incited researchers to design salinity gradient solar ponds to collect and store solar energy at a lower cost. It is in this context that the present research work lies to focus on the numerical study of the transient hydrodynamic, heat and mass transfer in a salinity gradient solar pond. The problem is tackled using the dimensionless governing equations of Navier–Stokes, thermal energy and mass transfer, which are solved numerically by finite-volume method to provide the temperature, concentration and velocity fields in transient regime. The pond is filled with salty water of various salinities to form three zones of salty water: Upper Convective Zone (UCZ), Non-Convective Zone (NCZ) and Lower Convective Zone (LCZ). To prevent convective movements induced by the internal heating of salty water due to solar radiation absorption, a salinity gradient is used in the solar pond. Representative results illustrating the influence of internal Rayleigh number on the thermal performance of the pond and the effect of the aspect ratio on the distribution of temperature and velocity fields in the salinity gradient solar pond (SGSP) are discussed. In addition, results for the transient average temperature of UCZ and LCZ are presented and discussed for various parametric conditions.

Ridha Boudhiaf; Mounir Baccar

2014-01-01T23:59:59.000Z

462

Investigations of Protostellar Outflow Launching and Gas Entrainment: Hydrodynamic Simulations and Molecular Emission  

E-Print Network [OSTI]

We investigate protostellar outflow evolution, gas entrainment, and star formation efficiency using radiation-hydrodynamic simulations of isolated, turbulent low-mass cores. We adopt an X-wind launching model, in which the outflow rate is coupled to the instantaneous protostellar accretion rate and evolution. We vary the outflow collimation angle from $\\theta$=0.01-0.1 and find that even well collimated outflows effectively sweep up and entrain significant core mass. The Stage 0 lifetime ranges from 0.14-0.19 Myr, which is similar to the observed Class 0 lifetime. The star formation efficiency of the cores spans 0.41-0.51. In all cases, the outflows drive strong turbulence in the surrounding material. Although the initial core turbulence is purely solenoidal by construction, the simulations converge to approximate equipartition between solenoidal and compressive motions due to a combination of outflow driving and collapse. When compared to a simulation of a cluster of protostars, which is not gravitationally ...

Offner, S S R

2013-01-01T23:59:59.000Z

463

Thin film hydrodynamic lubrication of flying heads in magnetic disk storages  

Science Journals Connector (OSTI)

Typical hydrodynamic lubrication problems commonly encountered in the ultrathin spacing between a computer flying head and a magnetic disk are reviewed. In magnetic disk storages, minimizing the spacing between the head and disk is essential to promote the largest possible increase in magnetic bit density. In the small (nearly 1.0 ?m) spacing that has recently been attained, the rarefaction effects owing to the molecular mean free path become dominant. Specifically, in this paper the three governing equations resulting from the first- and second-order slip-flow models and from the linearized Boltzmann equation are compared. Next, some numerical approaches to eliminating the instability in pressure distribution in the high bearing number region are described. Surface roughness effects are also a principal concern in thin spacing. A mixed lubrication model which enables the analysis of the start/stop operation and the average film thickness theory for one- and two-dimensional roughnesses is summarized. Finally, from the viewpoint of practical head design, the slider dynamic characteristics and related slider design factors are discussed.

Yasunaga Mitsuya

1987-01-01T23:59:59.000Z

464

Efficient Calculation of Dewatered and Entrapped Areas Using Hydrodynamic Modeling and GIS  

SciTech Connect (OSTI)

River waters downstream of a hydroelectric project are often subject to rapidly changing discharge. Abrupt decreases in discharge can quickly dewater and expose some areas and isolate other areas from the main river channel, potentially stranding or entrapping fish, which often results in mortality. A methodology is described to estimate the areas dewatered or entrapped by a specific reduction in upstream discharge. A one-dimensional hydrodynamic model was used to simulate steady flows. Using flow simulation results from the model and a geographic information system (GIS), estimates of dewatered and entrapped areas were made for a wide discharge range. The methodology was applied to the Hanford Reach of the Columbia River in central Washington State. Results showed that a 280 m$^3$/s discharge reduction affected the most area at discharges less than 3400 m$^3$/s. At flows above 3400 m$^3$/s, the affected area by a 280 m$^3$/s discharge reduction (about 25 ha) was relatively constant. A 280 m$^3$/s discharge reduction at lower flows affected about twice as much area. The methodology and resulting area estimates were, at the time of writing, being used to identify discharge regimes, and associated water surface elevations, that might be expected to minimize adverse impacts on juvenile fall chinook salmon (\\emph{Oncorhynchus tshawytscha}) that rear in the shallow near-shore areas in the Hanford Reach.

Richmond, Marshall C.; Perkins, William A.

2009-12-01T23:59:59.000Z

465

The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres  

E-Print Network [OSTI]

Context. Europium is an almost pure r-process element, which may be useful as a reference in nucleocosmochronology. Aims. To determine the photospheric solar abundance using CO5BOLD 3-D hydrodynamical model atmospheres. Methods. Disc-centre and integrated-flux observed solar spectra are used. The europium abundance is derived from the equivalent width measurements. As a reference 1D model atmospheres have been used, in addition. Results. The europium photospheric solar abundance is 0.52 +- 0.02 in agreement with previous determinations. We also determine the photospheric isotopic fraction of Eu(151) to be 49 % +- 2.3 % from the intensity spectra and 50% +-2.3 from the flux spectra. This compares well to the the meteoritic isotopic fraction 47.8%. We explore the 3D corrections also for dwarfs and sub-giants in the temperature range ~5000 K to ~6500 K and solar and 1/10--solar metallicities and find them to be negligible for all the models investigated. Conclusions. Our photospheric Eu abundance is in good agreement with previous determinations based on 1D models. This is in line with our conclusion that 3D effects for this element are negligible in the case of the Sun.

A. Mucciarelli; E. Caffau; B. Freytag; H. -G. Ludwig; P. Bonifacio

2008-03-06T23:59:59.000Z

466

Hydrodynamics of Embedded Planets' First Atmospheres. II. A Rapid Recycling of Atmospheric Gas  

E-Print Network [OSTI]

Following Paper I we investigate the properties of atmospheres that form around small protoplanets embedded in a protoplanetary disc by conducting hydrodynamical simulations. These are now extended to three dimensions, employing a spherical grid centred on the planet. Compression of gas is shown to reduce rotational motions. Contrasting the 2D case, no clear boundary demarcates bound atmospheric gas from disc material; instead, we find an open system where gas enters the Bondi sphere at high latitudes and leaves through the midplane regions, or, vice versa, when the disc gas rotates sub-Keplerian. The simulations do not converge to a time-independent solution; instead, the atmosphere is characterized by a time-varying velocity field. Of particular interest is the timescale to replenish the atmosphere by nebular gas, $t_\\mathrm{replenish}$. It is shown that the replenishment rate, $M_\\mathrm{atm}/t_\\mathrm{replenish}$, can be understood in terms of a modified Bondi accretion rate, $\\sim$$R_\\mathrm{Bondi}^2\\rho...

Ormel, Chris W; Kuiper, Rolf

2014-01-01T23:59:59.000Z

467

Hydrodynamic Modeling of Air Blast Propagation from the Humble Redwood Chemical High Explosive Detonations Using GEODYN  

SciTech Connect (OSTI)

Two-dimensional axisymmetric hydrodynamic models were developed using GEODYN to simulate the propagation of air blasts resulting from a series of high explosive detonations conducted at Kirtland Air Force Base in August and September of 2007. Dubbed Humble Redwood I (HR-1), these near-surface chemical high explosive detonations consisted of seven shots of varying height or depth of burst. Each shot was simulated numerically using GEODYN. An adaptive mesh refinement scheme based on air pressure gradients was employed such that the mesh refinement tracked the advancing shock front where sharp discontinuities existed in the state variables, but allowed the mesh to sufficiently relax behind the shock front for runtime efficiency. Comparisons of overpressure, sound speed, and positive phase impulse from the GEODYN simulations were made to the recorded data taken from each HR-1 shot. Where the detonations occurred above ground or were shallowly buried (no deeper than 1 m), the GEODYN model was able to simulate the sound speeds, peak overpressures, and positive phase impulses to within approximately 1%, 23%, and 6%, respectively, of the actual recorded data, supporting the use of numerical simulation of the air blast as a forensic tool in determining the yield of an otherwise unknown explosion.

Chipman, V D

2011-09-20T23:59:59.000Z

468

A new multidimensional, energy-dependent two-moment transport code for neutrino-hydrodynamics  

E-Print Network [OSTI]

We present the new code ALCAR developed to model multidimensional, multi energy-group neutrino transport in the context of supernovae and neutron-star mergers. The algorithm solves the evolution equations of the 0th- and 1st-order angular moments of the specific intensity, supplemented by an algebraic relation for the 2nd-moment tensor to close the system. The scheme takes into account frame-dependent effects of order O(v/c) as well as the most important types of neutrino interactions. The transport scheme is significantly more efficient than a multidimensional solver of the Boltzmann equation, while it is more accurate and consistent than the flux-limited diffusion method. The finite-volume discretization of the essentially hyperbolic system of moment equations employs methods well-known from hydrodynamics. For the time integration of the potentially stiff moment equations we employ a scheme in which only the local source terms are treated implicitly, while the advection terms are kept explicit, thereby allo...

Just, Oliver; Janka, H -Thomas

2015-01-01T23:59:59.000Z

469

Simulation and experimental verification of a hydrodynamic model for a dual fluidized Bed gasifier  

Science Journals Connector (OSTI)

Abstract We propose a revised 2-D energy-minimization multi-scale (EMMS) model based on a two-fluid model to perform the hydrodynamic character analysis of a pilot-scale full-loop dual fluidized bed gasifier (DFBG), which consists of a riser, a cyclone with a down-comer, a bubbling fluidized bed (BFB), and a loop-seal. The EMMS model is used to analyze the interaction force between the gas and solid phases in the DFBG. For comparison, O'Brien & Syamlal's drag heterogeneous force coefficient correction is also analyzed. The instantaneous particle profiles are described by the calculated results. The local and overall flow characteristics are determined by the solids concentration under different fluidization conditions. The effects of the gas velocities in the riser and the recycle gas velocities in the U loop seal on the axial solids concentration and solids circulation profiles, as well as the flow heterogeneity in sub-zones of the riser are investigated. The numerical results are in good agreement with the experimental data, indicating that the EMMS model is appropriate to simulate the heterogeneous gas–solids two-phase flow in DFBG.

Xueyao Wang; Jing Lei; Xiang Xu; Zhengzhong Ma; Yunhan Xiao

2014-01-01T23:59:59.000Z

470

Influence of geometric parameters on the hydrodynamics control of solar chimney  

Science Journals Connector (OSTI)

Abstract Hydrogen generating station (HGS) by water electrolysis is based on three principal compartments: hydraulic pumping system, water electrolysis process and energy supply whose can be free source like solar chimney power plans (SCPP). The HGS can be controlled if governed one of these three compartments especially the energy supply SCPP. The aim of this study is to investigate numerically the airflow behavior through a Solar Chimney. The transport equations that describe the flow, for different geometric tower parameters were modeled and solved numerically using the finite volume method. This methodology allows us a detailed visualization of the effects of some geometrical parameters such as the tower height and tower radius. It has been shown in this work that the dimensions of the tower play an important role in designing of such systems by increasing or decreasing the mass flow rate. Consequently, the hydrodynamic field is directly controlled by varying the tower dimensions. However the thermal field is indirectly controlled by decreasing the system mean temperature.

M. Lebbi; T. Chergui; H. Boualit; I. Boutina

2014-01-01T23:59:59.000Z

471

3D Hydrodynamic & Radiative Transfer Models of X-ray Emission from Colliding Wind Binaries  

E-Print Network [OSTI]

Colliding wind binaries (CWBs) are unique laboratories for X-ray astrophysics. The massive stars in these systems possess powerful stellar winds with speeds up to $\\sim$3000 km s$^{-1}$, and their collision leads to hot plasma (up to $\\sim10^8$K) that emit thermal X-rays (up to $\\sim$10 keV). Many X-ray telescopes have observed CWBs, including Suzaku, and our work aims to model these X-ray observations. We use 3D smoothed particle hydrodynamics (SPH) to model the wind-wind interaction, and then perform 3D radiative transfer to compute the emergent X-ray flux, which is folded through X-ray telescopes' response functions to compare directly with observations. In these proceedings, we present our models of Suzaku observations of the multi-year-period, highly eccentric systems $\\eta$ Carinae and WR 140. The models reproduce the observations well away from periastron passage, but only $\\eta$ Carinae's X-ray spectrum is reproduced at periastron; the WR 140 model produces too much flux during this more complicated p...

Russell, Christopher M P; Owocki, Stanley P; Corcoran, Michael F; Hamaguchi, Kenji; Sugawara, Yasuharu

2014-01-01T23:59:59.000Z

472

3D Simulation of Dam-break effect on a Solid Wall using Smoothed Particle Hydrodynamics  

E-Print Network [OSTI]

Dam is built for water supply, water flow or flooding control and electricity energy storage, but in other hand, dam is one of the most dangerous natural disaster in many countries including in Indonesia. The impact of dam break in neighbour area and is huge and many flooding in remote area, as happen in Dam Situ Gintung in Tangerang (close to Jakarta) in 2009. Smoothed Particle Hydrodynamics (SPH), is one of numerical method based on Lagrangian grid which is ap- plied in astrophysical simulation may be used to solve the simulation on dam break effect. The development of SPH methods become alternative methods to solving Navier Stokes equation, which is main key in fluid dynamic simulation. In this paper, SPH is developed for supporting solid par- ticles in use for 3D dam break effect (3D-DBE) simulation. Solid particle have been treated same as fluid particles with additional calculation for converting gained position became translation and rotation of solid object in a whole body. With this capability, the r...

Suprijadi,; Naa, Christian; Putra, Anggy Trisnawan

2013-01-01T23:59:59.000Z

473

The effect of particle inlet conditions on FCC riser hydrodynamics and product yields.  

SciTech Connect (OSTI)

Essential to today's modern refineries and the gasoline production process are fluidized catalytic cracking units. By using a computational fluid dynamics (CFD) code developed at Argonne National Laboratory to simulate the riser, parametric and sensitivity studies were performed to determine the effect of catalyst inlet conditions on the riser hydrodynamics and on the product yields. Simulations were created on the basis of a general riser configuration and operating conditions. The results of this work are indications of riser operating conditions that will maximize specific product yields. The CFD code is a three-dimensional, multiphase, turbulent, reacting flow code with phenomenological models for particle-solid interactions, droplet evaporation, and chemical kinetics. The code has been validated against pressure, particle loading, and product yield measurements. After validation of the code, parametric studies were performed on various parameters such as the injection velocity of the catalyst, the angle of injection, and the particle size distribution. The results indicate that good mixing of the catalyst particles with the oil droplets produces a high degree of cracking in the riser.

Chang, S. L.; Golchert, B.; Lottes, S. A.; Zhou, C. Q.; Huntsinger, A.; Petrick, M.

1999-10-11T23:59:59.000Z

474

Hydrodynamics of cell-cell mechanical signaling in the initial stages of aggregation  

Science Journals Connector (OSTI)

Mechanotactic cell motility has recently been shown to be a key player in the initial aggregation of crawling cells such as leukocytes and amoebae. The effects of mechanotactic signaling in the early aggregation of amoeboid cells are here investigated using a general mathematical model based on known biological evidence. We elucidate the hydrodynamic fundamentals of the direct guiding of a cell through mechanotaxis in the case where one cell transmits a mechanotactic signal through the fluid flow by changing its shape. It is found that any mechanosensing cells placed in the stimulus field of mechanical stress are able to determine the signal transmission direction with a certain angular dispersion which does not preclude the aggregation from happening. The ubiquitous presence of noise is accounted for by the model. Finally, the mesoscopic pattern of aggregation is obtained which constitutes the bridge between, on one hand, the microscopic world where the changes in the cell shape occur and, on the other hand, the cooperative behavior of the cells at the mesoscopic scale.

Roland Bouffanais and Dick K. P. Yue

2010-04-28T23:59:59.000Z

475

Order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind turbine arrays  

E-Print Network [OSTI]

Modern wind farms require significant land resources to separate each wind turbine from the adjacent turbine wakes. These aerodynamic constraints limit the amount of power that can be extracted from a given wind farm footprint. We conducted full-scale field tests of vertical-axis wind turbines in counter-rotating configurations under natural wind conditions. Whereas wind farms consisting of propeller-style turbines produce 2 to 3 watts of power per square meter of land area, these field tests indicate that power densities approaching 100 W m^-2 can be achieved by arranging vertical-axis wind turbines in layouts that enable them to extract energy from adjacent wakes. In addition, we calculated that the global wind resource available to 10-m tall turbines based on the present approach is approximately 225 trillion watts (TW), which significantly exceeds the global wind resource available to 80-m tall, propeller-style wind turbines, approximately 75 TW. This improvement is due to the closer spacing that can be a...

Dabiri, John O

2010-01-01T23:59:59.000Z

476

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part II: Mooring line and structural dynamics  

Science Journals Connector (OSTI)

Abstract The need to exploit enhanced wind resources far offshore as well as in deep waters requires the use of floating support structures to become economically viable. The conventional three-bladed horizontal axis wind turbine may not continue to be the optimal design for floating applications. Therefore it is important to assess alternative concepts in this context that may be more suitable. Vertical axis wind turbines (VAWTs) are a promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess their technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This second article focuses on the modelling of mooring systems and structural behaviour of floating VAWTs, discussing various mathematical models and their suitability within the context of developing a model of coupled dynamics. Emphasis is placed on computational aspects of model selection and development as computational efficiency is an important aspect during preliminary design stages. This paper has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu; Athanasios Kolios

2014-01-01T23:59:59.000Z

477

Radiation-Hydrodynamic Simulations of Massive Star Formation with Protostellar Outflows  

SciTech Connect (OSTI)

We report the results of a series of AMR radiation-hydrodynamic simulations of the collapse of massive star forming clouds using the ORION code. These simulations are the first to include the feedback effects protostellar outflows, as well as protostellar radiative heating and radiation pressure exerted on the infalling, dusty gas. We find that that outflows evacuate polar cavities of reduced optical depth through the ambient core. These enhance the radiative flux in the poleward direction so that it is 1.7 to 15 times larger than that in the midplane. As a result the radiative heating and outward radiation force exerted on the protostellar disk and infalling cloud gas in the equatorial direction are greatly diminished. The simultaneously reduces the Eddington radiation pressure barrier to high-mass star formation and increases the minimum threshold surface density for radiative heating to suppress fragmentation compared to models that do not include outflows. The strength of both these effects depends on the initial core surface density. Lower surface density cores have longer free-fall times and thus massive stars formed within them undergo more Kelvin contraction as the core collapses, leading to more powerful outflows. Furthermore, in lower surface density clouds the ratio of the time required for the outflow to break out of the core to the core free-fall time is smaller, so that these clouds are consequently influenced by outflows at earlier stages of collapse. As a result, outflow effects are strongest in low surface density cores and weakest in high surface density one. We also find that radiation focusing in the direction of outflow cavities is sufficient to prevent the formation of radiation pressure-supported circumstellar gas bubbles, in contrast to models which neglect protostellar outflow feedback.

Cunningham, A J; Klein, R I; Krumholz, M R; McKee, C F

2011-03-02T23:59:59.000Z

478

Three-dimensional general relativistic hydrodynamics II: long-term dynamics of single relativistic stars  

E-Print Network [OSTI]

This is the second in a series of papers on the construction and validation of a three-dimensional code for the solution of the coupled system of the Einstein equations and of the general relativistic hydrodynamic equations, and on the application of this code to problems in general relativistic astrophysics. In particular, we report on the accuracy of our code in the long-term dynamical evolution of relativistic stars and on some new physics results obtained in the process of code testing. The tests involve single non-rotating stars in stable equilibrium, non-rotating stars undergoing radial and quadrupolar oscillations, non-rotating stars on the unstable branch of the equilibrium configurations migrating to the stable branch, non-rotating stars undergoing gravitational collapse to a black hole, and rapidly rotating stars in stable equilibrium and undergoing quasi-radial oscillations. The numerical evolutions have been carried out in full general relativity using different types of polytropic equations of state using either the rest-mass density only, or the rest-mass density and the internal energy as independent variables. New variants of the spacetime evolution and new high resolution shock capturing (HRSC) treatments based on Riemann solvers and slope limiters have been implemented and the results compared with those obtained from previous methods. Finally, we have obtained the first eigenfrequencies of rotating stars in full general relativity and rapid rotation. A long standing problem, such frequencies have not been obtained by other methods. Overall, and to the best of our knowledge, the results presented in this paper represent the most accurate long-term three-dimensional evolutions of relativistic stars available to date.

J. Font; T. Goodale; S. Iyer; M. Miller; L. Rezzolla; E. Seidel; N. Stergioulas; W. Suen; M. Tobias

2001-10-09T23:59:59.000Z

479

Combined Modeling of Acceleration, Transport, and Hydrodynamic Response in Solar Flares. I. The Numerical Model  

Science Journals Connector (OSTI)

Acceleration and transport of high-energy particles and fluid dynamics of atmospheric plasma are interrelated aspects of solar flares, but for convenience and simplicity they were artificially separated in the past. We present here self-consistently combined Fokker-Planck modeling of particles and hydrodynamic simulation of flare plasma. Energetic electrons are modeled with the Stanford unified code of acceleration, transport, and radiation, while plasma is modeled with the Naval Research Laboratory flux tube code. We calculated the collisional heating rate directly from the particle transport code, which is more accurate than those in previous studies based on approximate analytical solutions. We repeated the simulation of Mariska et al. with an injection of power law, downward-beamed electrons using the new heating rate. For this case, a ~10% difference was found from their old result. We also used a more realistic spectrum of injected electrons provided by the stochastic acceleration model, which has a smooth transition from a quasi-thermal background at low energies to a nonthermal tail at high energies. The inclusion of low-energy electrons results in relatively more heating in the corona (versus chromosphere) and thus a larger downward heat conduction flux. The interplay of electron heating, conduction, and radiative loss leads to stronger chromospheric evaporation than obtained in previous studies, which had a deficit in low-energy electrons due to an arbitrarily assumed low-energy cutoff. The energy and spatial distributions of energetic electrons and bremsstrahlung photons bear signatures of the changing density distribution caused by chromospheric evaporation. In particular, the density jump at the evaporation front gives rise to enhanced emission, which, in principle, can be imaged by X-ray telescopes. This model can be applied to investigate a variety of high-energy processes in solar, space, and astrophysical plasmas.

Wei Liu; Vahé Petrosian; John T. Mariska

2009-01-01T23:59:59.000Z

480

COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC RESPONSE IN SOLAR FLARES. I. THE NUMERICAL MODEL  

SciTech Connect (OSTI)

Acceleration and transport of high-energy particles and fluid dynamics of atmospheric plasma are interrelated aspects of solar flares, but for convenience and simplicity they were artificially separated in the past. We present here self-consistently combined Fokker-Planck modeling of particles and hydrodynamic simulation of flare plasma. Energetic electrons are modeled with the Stanford unified code of acceleration, transport, and radiation, while plasma is modeled with the Naval Research Laboratory flux tube code. We calculated the collisional heating rate directly from the particle transport code, which is more accurate than those in previous studies based on approximate analytical solutions. We repeated the simulation of Mariska et al. with an injection of power law, downward-beamed electrons using the new heating rate. For this case, a {approx}10% difference was found from their old result. We also used a more realistic spectrum of injected electrons provided by the stochastic acceleration model, which has a smooth transition from a quasi-thermal background at low energies to a nonthermal tail at high energies. The inclusion of low-energy electrons results in relatively more heating in the corona (versus chromosphere) and thus a larger downward heat conduction flux. The interplay of electron heating, conduction, and radiative loss leads to stronger chromospheric evaporation than obtained in previous studies, which had a deficit in low-energy electrons due to an arbitrarily assumed low-energy cutoff. The energy and spatial distributions of energetic electrons and bremsstrahlung photons bear signatures of the changing density distribution caused by chromospheric evaporation. In particular, the density jump at the evaporation front gives rise to enhanced emission, which, in principle, can be imaged by X-ray telescopes. This model can be applied to investigate a variety of high-energy processes in solar, space, and astrophysical plasmas.

Liu Wei [Stanford-Lockheed Institute for Space Research, 466 Via Ortega, Cypress Hall, Stanford, CA 94305-4085 (United States); Petrosian, Vahe [Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States); Mariska, John T. [Naval Research Laboratory, Code 7673, Washington, DC 20375-5000 (United States)

2009-09-10T23:59:59.000Z