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1

Dual Axis Radiographic Hydrodynamic Test Facility, IG-0599 |...  

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

Administration Other Agencies You are here Home Dual Axis Radiographic Hydrodynamic Test Facility, IG-0599 Dual Axis Radiographic Hydrodynamic Test Facility, IG-0599 The Dual...

2

DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility  

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

Radiographic Hydrodynamic Test Facility DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT, supports a critical component of LANL's primary mission: to ensure...

3

Dual Axis Radiographic Hydrodynamic Test Facility  

NLE Websites -- All DOE Office Websites (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

4

DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility  

NLE Websites -- All DOE Office Websites (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.

5

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

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

6

Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility  

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

8:45 am BILLING CODE 6450-01-P Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility AGENCY: Department of Energy. ACTION: Record of decision. SUMMARY: The...

7

Dual axis radiographic hydrodynamic test facility. Final environmental impact statement, Volume 2: Public comments and responses  

Science Conference Proceedings (OSTI)

On May 12, 1995, the U.S. Department of Energy (DOE) issued the draft Dual Axis Radiographic Hydrodynamic Test Facility Environmental Impact Statement (DARHT EIS) for review by the State of New Mexico, Indian Tribes, local governments, other Federal agencies, and the general public. DOE invited comments on the accuracy and adequacy of the draft EIS and any other matters pertaining to their environmental reviews. The formal comment period ran for 45 days, to June 26, 1995, although DOE indicated that late comments would be considered to the extent possible. As part of the public comment process, DOE held two public hearings in Los Alamos and Santa Fe, New Mexico, on May 31 and June 1, 1995. In addition, DOE made the draft classified supplement to the DARHT EIS available for review by appropriately cleared individuals with a need to know the classified information. Reviewers of the classified material included the State of New Mexico, the U.S. Environmental Protection Agency, the Department of Defense, and certain Indian Tribes. Volume 2 of the final DARHT EIS contains three chapters. Chapter 1 includes a collective summary of the comments received and DOE`s response. Chapter 2 contains the full text of the public comments on the draft DARHT EIS received by DOE. Chapter 3 contains DOE`s responses to the public comments and an indication as to how the comments were considered in the final EIS.

NONE

1995-08-01T23:59:59.000Z

8

Dual Axis Radiographic Hydrodynamic Test Facility | National...  

National Nuclear Security Administration (NNSA)

program, the DARHT is the world's most powerful x-ray machine. DARHT consists of two electron accelerators oriented at right angles to one another. Each accelerator creates a...

9

Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility  

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

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.

10

SCANNED DARHT.pub  

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

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

11

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

SciTech Connect

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

12

Microsoft Word - Defense Science Quarterly 08-08.doc  

National Nuclear Security Administration (NNSA)

the Director 2 Derivative Applications of Pulsed Power Science and Technology 4 LANSCE-R Means More Beam for National Security Research 6 Dual Axis Radiographic Hydrodynamics...

13

Diode magnetic-field influence on radiographic spot size  

Science Conference Proceedings (OSTI)

Flash radiography of hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories. The Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos was developed for flash radiography of large hydrodynamic experiments. Two linear induction accelerators (LIAs) produce the bremsstrahlung radiographic source spots for orthogonal views of each experiment ('hydrotest'). The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. For time resolution of the hydrotest dynamics, the 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by slicing them out of a longer pulse that has a 1.6-{micro}s flattop. Both axes now routinely produce radiographic source spot sizes having full-width at half-maximum (FWHM) less than 1 mm. To further improve on the radiographic resolution, one must consider the major factors influencing the spot size: (1) Beam convergence at the final focus; (2) Beam emittance; (3) Beam canonical angular momentum; (4) Beam-motion blur; and (5) Beam-target interactions. Beam emittance growth and motion in the accelerators have been addressed by careful tuning. Defocusing by beam-target interactions has been minimized through tuning of the final focus solenoid for optimum convergence and other means. Finally, the beam canonical angular momentum is minimized by using a 'shielded source' of electrons. An ideal shielded source creates the beam in a region where the axial magnetic field is zero, thus the canonical momentum zero, since the beam is born with no mechanical angular momentum. It then follows from Busch's conservation theorem that the canonical angular momentum is minimized at the target, at least in principal. In the DARHT accelerators, the axial magnetic field at the cathode is minmized by using a 'bucking coil' solenoid with reverse polarity to cancel out whatever solenoidal beam transport field exists there. This is imperfect in practice, because of radial variation of the total field across the cathode surface, solenoid misalignments, and long-term variability of solenoid fields for given currents. Therefore, it is useful to quantify the relative importance of canonical momentum in determining the focal spot, and to establish a systematic methodology for tuning the bucking coils for minimum spot size. That is the purpose of this article. Section II provides a theoretical foundation for understanding the relative importance of the canonical momentum. Section III describes the results of simulations used to quantify beam parameters, including the momentum, for each of the accelerators. Section IV compares the two accelerators, especially with respect to mis-tuned bucking coils. Finally, Section IV concludes with a methodology for optimizing the bucking coil settings.

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

2012-09-04T23:59:59.000Z

14

Quarterly SSP Experiment Summary-FY13-4Q final ...  

National Nuclear Security Administration (NNSA)

Quarter FY13Q1 FY13Q2 FY13Q3 FY13Q4 Dual Axis Radiographic Hydrodynamic Test (DARHT) facility LANL Integrated or Focused non- nuclear weapons experiments DARHT captures high...

15

70template.factsheets.indd  

NLE Websites -- All DOE Office Websites (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

16

EIS-0228: Record of Decision | Department of Energy  

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

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

17

EIS-0228: Record of Decision | Department of Energy  

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

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

18

Radiation Hydrodynamics  

DOE Green Energy (OSTI)

The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is to distinguish hydrogen atoms from helium atoms, for instance. There are all just components of a mixed fluid in this case. So why do we have a special subject called ''radiation hydrodynamics'', when photons are just one of the many kinds of particles that comprise our fluid? The reason is that photons couple rather weakly to the atoms, ions and electrons, much more weakly than those particles couple with each other. Nor is the matter-radiation coupling negligible in many problems, since the star or nebula may be millions of mean free paths in extent. Radiation hydrodynamics exists as a discipline to treat those problems for which the energy and momentum coupling terms between matter and radiation are important, and for which, since the photon mean free path is neither extremely large nor extremely small compared with the size of the system, the radiation field is not very easy to calculate. In the theoretical development of this subject, many of the relations are presented in a form that is described as approximate, and perhaps accurate only to order of {nu}/c. This makes the discussion cumbersome. Why are we required to do this? It is because we are using Newtonian mechanics to treat our fluid, yet its photon component is intrinsically relativistic; the particles travel at the speed of light. There is a perfectly consistent relativistic kinetic theory, and a corresponding relativistic theory of fluid mechanics, which is perfectly suited to describing the photon gas. But it is cumbersome to use this for the fluid in general, and we prefer to avoid it for cases in which the flow velocity satisfies {nu} << c. The price we pay is to spend extra effort making sure that the source-sink terms relating to our relativistic gas component are included in the equations of motion in a form that preserves overall conservation of energy and momentum, something that would be automatic if the relativistic equations were used throughout.

Castor, J I

2003-10-16T23:59:59.000Z

19

Lifshitz Hydrodynamics  

E-Print Network (OSTI)

We construct the hydrodynamics of quantum field theories with a Lifshitz scaling symmetry. New transport coefficients are allowed by the absence of boost invariance, however, only one is compatible with a local increase of the entropy density. The formulation is applicable, in general, to fluids with an explicit breaking of boost symmetry. We use a Drude model of a strange metal to study the physical effects of the new transport coefficient. It can be measured using electric fields with non-zero gradients, or via the heat production when an external force is turned on. Scaling arguments fix the resistivity to be linear in the temperature.

Carlos Hoyos; Bom Soo Kim; Yaron Oz

2013-04-28T23:59:59.000Z

20

Audit Report: IG-0599 | Department of Energy  

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

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

Note: This page contains sample records for the topic "dual-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

Dynamic Radiographic Imaging  

Science Conference Proceedings (OSTI)

A radiographic system recently developed by American and Russian collaborators is designed to capture multiple images of a dynamic event lasting less than 10 microseconds. Various optical and electro-optical components were considered and their performance compared. The final system employed a solid crystal of lutetium oxyorthosilicate doped with cerium (LSO:Ce or LSO) for X-ray-to-light conversion with a coherent fiber optic bundle to relay the scintillator image to a streak camera with charge coupled device (CCD) readout. Resolution and sensitivity studies were carried out for this system on two different sources of X-rays: a 20 MeV microtron and a 70 MeV betatron.

Volkov, A.; Turley, D.; Veeser, L.; Lukyanov, N.; Yegorov, N.; Baker, S.A.; Mirenko, V.; Lewis, W.; Kuropatkin, Y.

1999-06-01T23:59:59.000Z

22

National Security, Weapons Science  

NLE Websites -- All DOE Office Websites (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

23

Film holder for radiographing tubing  

DOE Patents (OSTI)

A film cassette is provided which may be easily placed about tubing or piping and readily held in place while radiographic inspection is performed. A pair of precurved light-impervious semi-rigid plastic sheets, hinged at one edge, enclose sheet film together with any metallic foils or screens. Other edges are made light-tight with removable caps, and the entire unit is held securely about the object to be radiographed with a releasable fastener such as a strip of Velcro.

Davis, Earl V. (Oak Ridge, TN); Foster, Billy E. (Oak Ridge, TN)

1976-01-01T23:59:59.000Z

24

Radiographic Inspection of Fueled Clads  

SciTech Connect

Five general purpose heat source (GPHS) fueled clads were radiographically inspected at the Idaho National Laboratory (INL). The girth weld region of each clad had previously passed visual examination, ring gauge test, and leak test but showed “positive” indications on the ultrasonic (UT) test. Positive ultrasonic indications are allowable under certain weld conditions; radiographic inspection provides a secondary nonintrusive means of clad inspection and may confirm allowable anomalies from the UT inspection. All the positive UT indications were found to exhibit allowable weld shield fusion or mismatch conditions. No indication of void defects was found. One additional clad (FCO371) was deemed unacceptable for radiographic inspection due to an unknown black substance that obscured the angular origin on the weld so that the angular offset to the UT indication could not be found.

Timothy J. Roney; Karen M. Wendt

2005-04-01T23:59:59.000Z

25

Digital Radiographic Image Storage and Retrieval  

Science Conference Proceedings (OSTI)

Fabrication and construction radiographs of nuclear plant components contain information valuable for clarifying inservice inspection results and assessing component remaining life. Preservation of radiographic information has become an issue in light of observed instances of degraded radiographs in nuclear plant collections. This report summarizes results to date of a project to provide guidance for evaluating a radiographic film collection and progress on establishing film digitization criteria as an a...

1994-01-01T23:59:59.000Z

26

Page not found | Department of Energy  

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

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)

27

Skew resisting hydrodynamic seal  

DOE Patents (OSTI)

A novel hydrodynamically lubricated compression type rotary seal that is suitable for lubricant retention and environmental exclusion. Particularly, the seal geometry ensures constraint of a hydrodynamic seal in a manner preventing skew-induced wear and provides adequate room within the seal gland to accommodate thermal expansion. The seal accommodates large as-manufactured variations in the coefficient of thermal expansion of the sealing material, provides a relatively stiff integral spring effect to minimize pressure-induced shuttling of the seal within the gland, and also maintains interfacial contact pressure within the dynamic sealing interface in an optimum range for efficient hydrodynamic lubrication and environment exclusion. The seal geometry also provides for complete support about the circumference of the seal to receive environmental pressure, as compared the interrupted character of seal support set forth in U.S. Pat. Nos. 5,873,576 and 6,036,192 and provides a hydrodynamic seal which is suitable for use with non-Newtonian lubricants.

Conroy, William T. (Pearland, TX); Dietle, Lannie L. (Sugar Land, TX); Gobeli, Jeffrey D. (Houston, TX); Kalsi, Manmohan S. (Houston, TX)

2001-01-01T23:59:59.000Z

28

Nonlinear hydrodynamics. Lecture 9  

SciTech Connect

A very sophisticated method for calculating the stability and pulsations of stars which make contact with actual observations of the stellar behavior, hydrodynamic calculations are very simple in principle. Conservation of mass can be accounted for by having mass shells that are fixed with their mass for all time. Motions of these shells can be calculated by taking the difference between the external force of gravity and that from the local pressure gradient. The conservation of energy can be coupled to this momentum conservation equation to give the current temperatures, densities, pressures, and opacities at the shell centers, as well as the positions, velocities, and accelerations of the mass shell interfaces. Energy flow across these interfaces can be calculated from the current conditions, and this energy is partitioned between internal energy and the work done on or by the mass shell. We discuss here only the purely radial case for hydrodynamics because it is very useful for stellar pulsation studies.

Cox, A.N.

1983-03-14T23:59:59.000Z

29

Load responsive hydrodynamic bearing  

Science Conference Proceedings (OSTI)

A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

Kalsi, Manmohan S. (Houston, TX); Somogyi, Dezso (Sugar Land, TX); Dietle, Lannie L. (Stafford, TX)

2002-01-01T23:59:59.000Z

30

BOGlanl.working.indd  

NLE Websites -- All DOE Office Websites (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

31

Digital radiographic systems detect boiler tube cracks  

SciTech Connect

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

32

Inertial coupling for point particle fluctuating hydrodynamics  

Science Conference Proceedings (OSTI)

A method for particle hydrodynamics based on an hybrid Eulerian-Lagrangian approach is presented. Particle dynamics are solved in continuum space while the fluid equations are solved in an Eulerian mesh, and described by finite volume fluctuating hydrodynamics. ...

F. Balboa Usabiaga; I. Pagonabarraga; R. Delgado-Buscalioni

2013-02-01T23:59:59.000Z

33

H1616 Shipping Container Radiographic Inspection Report  

Science Conference Proceedings (OSTI)

The HI616 shipping container is a certified type B(U) packaging used by the Department of Energy (DOE) to ship tritium in support of defense programs. During the 1997 recertification of the container, DOE became concerned about the possible cracking of the polyurethane foam in the overpacks of the 2300 containers currently in service. In response, Sandia National Laboratories (SNL) initiated a radiographic inspection program to determine if cracking of the foam was occurring in the H1616 overpacks. SNL developed the radiographic technique for inspecting the foam and contracted the Savannah River Site's Tritium Engineering division to inspect a representative sample of overpacks in service. This report details the development process and the results of all of the radiography performed both at SNL and Savannah River.

Tipton, D.G.

1998-11-01T23:59:59.000Z

34

A Radiographic Technique With Heavy Ion Microbeams  

SciTech Connect

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

35

Nondestructive Evaluation: Radiation Safety for Radiographic Operations  

Science Conference Proceedings (OSTI)

Radiation safety in radiographic operations at nuclear facilities is typically more difficult than at other types of industrial and commercial facilities. Radiography at nuclear facilities is typically conducted where exclusion areas can involve several elevations, multiple doorway entrances and wall penetrations, hidden and locked rooms, and active radiation monitors and alarms. During outages, a team of nondestructive examination (NDE) personnel, maintenance and craft workers, radiation protection tech...

2009-11-12T23:59:59.000Z

36

Disruptive Innovation in Numerical Hydrodynamics  

Science Conference Proceedings (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

37

Radiographic X-Ray Pulse Jitter  

Science Conference Proceedings (OSTI)

The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

2011-01-15T23:59:59.000Z

38

Hydromechanical transmission with hydrodynamic drive  

DOE Patents (OSTI)

This transmission has a first planetary gear assembly having first input means connected to an input shaft, first output means, and first reaction means, and a second planetary gear assembly having second input means connected to the first input means, second output means, and second reaction means connected directly to the first reaction means by a reaction shaft. First clutch means, when engaged, connect the first output means to an output shaft in a high driving range. A hydrodynamic drive is used; for example, a torque converter, which may or may not have a stationary case, has a pump connected to the second output means, a stator grounded by an overrunning clutch to the case, and a turbine connected to an output member, and may be used in a starting phase. Alternatively, a fluid coupling or other type of hydrodynamic drive may be used. Second clutch means, when engaged, for connecting the output member to the output shaft in a low driving range. A variable-displacement hydraulic unit is mechanically connected to the input shaft, and a fixed-displacement hydraulic unit is mechanically connected to the reaction shaft. The hydraulic units are hydraulically connected together so that when one operates as a pump the other acts as a motor, and vice versa. Both clutch means are connected to the output shaft through a forward-reverse shift arrangement. It is possible to lock out the torque converter after the starting phase is over.

Orshansky, Jr., deceased, Elias (LATE OF San Francisco, CA); Weseloh, William E. (San Diego, CA)

1979-01-01T23:59:59.000Z

39

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

40

Conservative, special-relativistic smoothed particle hydrodynamics  

Science Conference Proceedings (OSTI)

We present and test a new, special-relativistic formulation of smoothed particle hydrodynamics (SPH). Our approach benefits from several improvements with respect to earlier relativistic SPH formulations. It is self-consistently derived from the Lagrangian ... Keywords: Computational fluid dynamics, Shocks, Smoothed particle hydrodynamics, Special relativity

Stephan Rosswog

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

A hybrid Godunov method for radiation hydrodynamics  

Science Conference Proceedings (OSTI)

From a mathematical perspective, radiation hydrodynamics can be thought of as a system of hyperbolic balance laws with dual multiscale behavior (multiscale behavior associated with the hyperbolic wave speeds as well as multiscale behavior associated ... Keywords: Asymptotic preserving, Godunov method, Radiation hydrodynamics

Michael D. Sekora; James M. Stone

2010-09-01T23:59:59.000Z

42

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

43

Staggered Schemes for Fluctuating Hydrodynamics  

E-Print Network (OSTI)

We develop numerical schemes for solving the isothermal compressible and incompressible equations of fluctuating hydrodynamics on a grid with staggered momenta. We develop a second-order accurate spatial discretization of the diffusive, advective and stochastic fluxes that satisfies a discrete fluctuation-dissipation balance, and construct temporal discretizations that are at least second-order accurate in time deterministically and in a weak sense. Specifically, the methods reproduce the correct equilibrium covariances of the fluctuating fields to third (compressible) and second (incompressible) order in the time step, as we verify numerically. We apply our techniques to model recent experimental measurements of giant fluctuations in diffusively mixing fluids in a micro-gravity environment [A. Vailati et. al., Nature Communications 2:290, 2011]. Numerical results for the static spectrum of non-equilibrium concentration fluctuations are in excellent agreement between the compressible and incompressible simula...

Balboa, F; Delgado-Buscalioni, R; Donev, A; Fai, T; Griffith, B; Peskin, C S

2011-01-01T23:59:59.000Z

44

Temporal Integrators for Fluctuating Hydrodynamics  

E-Print Network (OSTI)

Including the effect of thermal fluctuations in traditional computational fluid dynamics requires developing numerical techniques for solving the stochastic partial differential equations of fluctuating hydrodynamics. These Langevin equations possess a special fluctuation-dissipation structure that needs to be preserved by spatio-temporal discretizations in order for the computed solution to reproduce the correct long-time behavior. In particular, numerical solutions should approximate the Gibbs-Boltzmann equilibrium distribution, and ideally this will hold even for large time step sizes. We describe finite-volume spatial discretizations for the fluctuating Burgers and fluctuating incompressible Navier-Stokes equations that obey a discrete fluctuation-dissipation balance principle just like the continuum equations. We develop implicit-explicit predictor-corrector temporal integrators for the resulting stochastic method-of-lines discretization. These stochastic Runge-Kutta schemes treat diffusion implicitly an...

Delong, S; Vanden-Eijnden, E; Donev, A

2012-01-01T23:59:59.000Z

45

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

46

Category:Hydrodynamic Testing Facility Type | Open Energy Information  

Open Energy Info (EERE)

Hydrodynamic Testing Facility Type Jump to: navigation, search This page contains all of the various types of technologies used in Hydrodynamic Testing Facilities for testing new...

47

The hydrodynamics of swimming microorganisms  

E-Print Network (OSTI)

Cell motility in viscous fluids is ubiquitous and affects many biological processes, including reproduction, infection, and the marine life ecosystem. Here we review the biophysical and mechanical principles of locomotion at the small scales relevant to cell swimming (tens of microns and below). The focus is on the fundamental flow physics phenomena occurring in this inertia-less realm, and the emphasis is on the simple physical picture. We review the basic properties of flows at low Reynolds number, paying special attention to aspects most relevant for swimming, such as resistance matrices for solid bodies, flow singularities, and kinematic requirements for net translation. Then we review classical theoretical work on cell motility: early calculations of the speed of a swimmer with prescribed stroke, and the application of resistive-force theory and slender-body theory to flagellar locomotion. After reviewing the physical means by which flagella are actuated, we outline areas of active research, including hydrodynamic interactions, biological locomotion in complex fluids, the design of small-scale artificial swimmers, and the optimization of locomotion strategies.

Eric Lauga; Thomas R. Powers

2008-12-15T23:59:59.000Z

48

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

49

Hydrodynamic gradient expansion in gauge theory plasmas  

E-Print Network (OSTI)

We utilize the fluid-gravity duality to investigate the large order behavior of hydrodynamic gradient expansion of the dynamics of a gauge theory plasma system. This corresponds to the inclusion of dissipative terms and transport coefficients of very high order. Using the dual gravity description, we calculate numerically the form of the stress tensor for a boost-invariant flow in a hydrodynamic expansion up to terms with 240 derivatives. We observe a factorial growth of gradient contributions at large orders, which indicates a zero radius of convergence of the hydrodynamic series. Furthermore, we identify the leading singularity in the Borel transform of the hydrodynamic energy density with the lowest nonhydrodynamic excitation corresponding to a `nonhydrodynamic' quasinormal mode on the gravity side.

Michal P. Heller; Romuald A. Janik; Przemyslaw Witaszczyk

2013-02-04T23:59:59.000Z

50

Shock wave formation in Rosenau's extended hydrodynamics  

E-Print Network (OSTI)

We study the extended hydrodynamics proposed by Philip Rosenau [Phys. Rev. A 40, 7193 (1989)] in the context of a regularization of the Chapman-Enskog expansion. We are able to prove that shock waves appear in finite time in Rosenau's extended Burgers' equation, and we discuss the physical implications of this fact and its connection with a possible extension of hydrodynamics to the short wavelength domain.

Carlos Escudero

2004-12-30T23:59:59.000Z

51

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":""}]}

52

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":""}]}

53

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":""}]}

54

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":""}]}

55

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":""}]}

56

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":""}]}

57

A quaternionic unification of electromagnetism and hydrodynamics  

E-Print Network (OSTI)

We have derived energy conservation equations from the quaternionic Newton's law that is compatible with Lorentz transformation. This Newton's law yields directly the Euler equation and other relations governing the fluid motion. With this formalism, the pressure contributes positively to the dynamics of the system in the same way mass does. Hydrodynamic equations are derived from Maxwell's equations by adopting an electromagnetohydrodynamics analogy. In this analogy the hydroelectric field is related to the local acceleration of the fluid and the Lorentz gauge is related to the incompressible fluid condition. An analogous Lorentz gauge in hydrodynamics is proposed. We have shown that the vorticity of the fluid is developed whenever the particle local acceleration of the fluid deviates from the velocity direction. We have shown that Lorentz force in electromagnetism corresponds to Euler force for fluids. Moreover, we have obtained a Faraday-like law and Ampere's -like law in Hydrodynamics.

Arbab, Arbab I

2010-01-01T23:59:59.000Z

58

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":""}]}

59

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":""}]}

60

A quaternionic unification of electromagnetism and hydrodynamics  

E-Print Network (OSTI)

We have derived energy conservation equations from the quaternionic Newton's law that is compatible with Lorentz transformation. This Newton's law yields directly the Euler equation and other equations governing the fluid motion. With this formalism, the pressure contributes positively to the dynamics of the system in the same way mass does. Hydrodynamic equations are derived from Maxwell's equations by adopting an electromagnetohydrodynamics (EMH) analogy. In this analogy the hydroelectric field is related to the local acceleration of the fluid and the Lorentz gauge is related to the incompressible fluid condition. An analogous Lorentz gauge in hydrodynamics is proposed. We have shown that the vorticity of the fluid is developed whenever the particle local acceleration of the fluid deviates from the velocity direction. We have also shown that Lorentz force in electromagnetism corresponds to Euler force in fluids. Moreover, we have obtained Gauss's, Faraday's and Ampere's -like laws in Hydrodynamics.

Arbab I. Arbab

2010-02-27T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Bounce-free spherical hydrodynamic implosion  

SciTech Connect

In a bounce-free spherical hydrodynamic implosion, the post-stagnation hot core plasma does not expand against the imploding flow. Such an implosion scheme has the advantage of improving the dwell time of the burning fuel, resulting in a higher fusion burn-up fraction. The existence of bounce-free spherical implosions is demonstrated by explicitly constructing a family of self-similar solutions to the spherically symmetric ideal hydrodynamic equations. When applied to a specific example of plasma liner driven magneto-inertial fusion, the bounce-free solution is found to produce at least a factor of four improvement in dwell time and fusion energy gain.

Kagan, Grigory; Tang Xianzhu; Hsu, Scott C.; Awe, Thomas J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2011-12-15T23:59:59.000Z

62

RADIOGRAPHIC MEASUREMENTS OF SNAP FUEL ELEMENT END GAPS  

SciTech Connect

A nondestructive method was developed for measuring the spacings at the ends of fuel rods in completed SNAP fuel elements. A precisely aligned radiographic technique is employed to form an undistorted image on extra fine grain radiographic film. The end gap is then measured with a 20 x measuring microscope. The radiographic technique, alignment gages, and film reading methods are described for measuring gaps at the blend end and blind end of the fuel elements. The accuracy of measurements at the blend end ranges from plus or minus 0.0005 in. for spacings up to 0.010 in. to plus or minus 0.002 in. for spacings above 0.025 in. The accuracy at the blind end is about one-half that at the blend end. (auth)

Barry, R.C.

1962-12-01T23:59:59.000Z

63

Standard specification for illuminators used for viewing industrial radiographs  

E-Print Network (OSTI)

1.1 The function of the illuminator is to provide sufficient illumination and viewing capabilities for the purpose of identification and interpretation of radiographic images. This specification provides the recommended minimum requirements for Industrial Radiographic Illuminators used for viewing industrial radiographic films using transmitted light sources. 1.2 The illuminator has to ensure the same safety for personnel, or users of any electric apparatus, as specified by electrical standards applicable in the country in which the illuminator is used. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.3 Values stated in SI units are to be regarded as the standard. The values given in parenthesis are provided for information only.

American Society for Testing and Materials. Philadelphia

2006-01-01T23:59:59.000Z

64

Stabilizing geometry for hydrodynamic rotary seals  

DOE Patents (OSTI)

A hydrodynamic sealing assembly including a first component having first and second walls and a peripheral wall defining a seal groove, a second component having a rotatable surface relative to said first component, and a hydrodynamic seal comprising a seal body of generally ring-shaped configuration having a circumference. The seal body includes hydrodynamic and static sealing lips each having a cross-sectional area that substantially vary in time with each other about the circumference. In an uninstalled condition, the seal body has a length defined between first and second seal body ends which varies in time with the hydrodynamic sealing lip cross-sectional area. The first and second ends generally face the first and second walls, respectively. In the uninstalled condition, the first end is angulated relative to the first wall and the second end is angulated relative to the second wall. The seal body has a twist-limiting surface adjacent the static sealing lip. In the uninstalled condition, the twist-limiting surface is angulated relative to the peripheral wall and varies along the circumference. A seal body discontinuity and a first component discontinuity mate to prevent rotation of the seal body relative to the first component.

Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX)

2010-08-10T23:59:59.000Z

65

General Relativity as Geometro-Hydrodynamics  

E-Print Network (OSTI)

In the spirit of Sakharov's `metric elasticity' proposal, we draw a loose analogy between general relativity and the hydrodynamic state of a quantum gas. In the `top-down' approach, we examine the various conditions which underlie the transition from some candidate theory of quantum gravity to general relativity. Our emphasis here is more on the `bottom-up' approach, where one starts with the semiclassical theory of gravity and examines how it is modified by graviton and quantum field excitations near and above the Planck scale. We mention three aspects based on our recent findings: 1) Emergence of stochastic behavior of spacetime and matter fields depicted by an Einstein-Langevin equation. The backreaction of quantum fields on the classical background spacetime manifests as a fluctuation-dissipation relation. 2) Manifestation of stochastic behavior in effective theories below the threshold arising from excitations above. The implication for general relativity is that such Planckian effects, though exponentially suppressed, is in principle detectable at sub-Planckian energies. 3) Decoherence of correlation histories and quantum to classical transition. From Gell-Mann and Hartle's observation that the hydrodynamic variables which obey conservation laws are most readily decohered, one can, in the spirit of Wheeler, view the conserved Bianchi identity obeyed by the Einstein tensor as an indication that general relativity is a hydrodynamic theory of geometry. Many outstanding issues surrounding the transition to general relativity are of a nature similar to hydrodynamics and mesoscopic physics.

B. L. Hu

1996-07-29T23:59:59.000Z

66

Hydrodynamic design of axial hydraulic turbines  

Science Conference Proceedings (OSTI)

This paper presents a complete methodology of the hydrodynamic design for the runner of axial hydraulic turbines (Kaplan) using the finite element method. The procedure starts with the parametric design of the meridian channel. Next, the stream traces ... Keywords: QTurbo3D, axial hydraulic turbines, design, meridian channel, runner blade

Daniel Balint; Viorel Câmpian

2011-04-01T23:59:59.000Z

67

Modeling early galaxies using radiation hydrodynamics  

Science Conference Proceedings (OSTI)

This simulation uses a flux-limited diffusion solver to explore the radiation hydrodynamics of early galaxies, in particular, the ionizing radiation created by Population III stars. At the time of this rendering, the simulation has evolved to a redshift ... Keywords: astrophysics, modeling, visualization

Joseph A. Insley; Rick Wagner; Robert Harkness; Daniel R. Reynolds; Michael L. Norman; Mark Hereld; Eric C. Olson; Michael E. Papka; Venkatram Vishwanath

2011-11-01T23:59:59.000Z

68

Simple Waves in Ideal Radiation Hydrodynamics  

E-Print Network (OSTI)

In the dynamic diffusion limit of radiation hydrodynamics, advection dominates diffusion; the latter primarily affects small scales and has negligible impact on the large scale flow. The radiation can thus be accurately regarded as an ideal fluid, i.e., radiative diffusion can be neglected along with other forms of dissipation. This viewpoint is applied here to an analysis of simple waves in an ideal radiating fluid. It is shown that much of the hydrodynamic analysis carries over by simply replacing the material sound speed, pressure and index with the values appropriate for a radiating fluid. A complete analysis is performed for a centered rarefaction wave, and expressions are provided for the Riemann invariants and characteristic curves of the one-dimensional system of equations. The analytical solution is checked for consistency against a finite difference numerical integration, and the validity of neglecting the diffusion operator is demonstrated. An interesting physical result is that for a material component with a large number of internal degrees of freedom and an internal energy greater than that of the radiation, the sound speed increases as the fluid is rarefied. These solutions are an excellent test for radiation hydrodynamic codes operating in the dynamic diffusion regime. The general approach may be useful in the development of Godunov numerical schemes for radiation hydrodynamics.

Bryan M. Johnson

2008-11-24T23:59:59.000Z

69

RELIABLE RADIOGRAPHIC INSPECTION OF FLEXIBLE RISERS FOR THE OIL INDUSTRY  

Science Conference Proceedings (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

70

Radiographic study of impact in polymer-bonded explosives  

SciTech Connect

Computer-tomography generated material-density maps from flash x-ray radiographs of the impact of cylinders of mockup polymer-bonded explosive (PBX) striking a steel plate. Comparison of the density fields with computer simulation allowed discrimination of rather complex deformation and flow models for insensitive explosives to be used in further studies of chemical reactions initiated by shock waves.

Fugelso, E.; Jacobson, J.D.; Karpp, R.R.; Jensen, R.

1981-01-01T23:59:59.000Z

71

CHARACTERIZATION OF THE ADVANCED RADIOGRAPHIC CAPABILITY FRONT END ON NIF  

SciTech Connect

We have characterized the Advanced Radiographic Capability injection laser system and demonstrated that it meets performance requirements for upcoming National Ignition Facility fusion experiments. Pulse compression was achieved with a scaled down replica of the meter-scale grating ARC compressor and sub-ps pulse duration was demonstrated at the Joule-level.

Haefner, C; Heebner, J; Dawson, J; Fochs, S; Shverdin, M; Crane, J K; Kanz, V K; Halpin, J; Phan, H; Sigurdsson, R; Brewer, W; Britten, J; Brunton, G; Clark, W; Messerly, M J; Nissen, J D; Nguyen, H; Shaw, B; Hackel, R; Hermann, M; Tietbohl, G; Siders, C W; Barty, C J

2009-07-15T23:59:59.000Z

72

Kinetic and hydrodynamic models of chemotactic aggregation  

E-Print Network (OSTI)

We derive general kinetic and hydrodynamic models of chemotactic aggregation that describe certain features of the morphogenesis of biological colonies (like bacteria, amoebae, endothelial cells or social insects). Starting from a stochastic model defined in terms of N coupled Langevin equations, we derive a nonlinear mean field Fokker-Planck equation governing the evolution of the distribution function of the system in phase space. By taking the successive moments of this kinetic equation and using a local thermodynamic equilibrium condition, we derive a set of hydrodynamic equations involving a damping term. In the limit of small frictions, we obtain a hyperbolic model describing the formation of network patterns (filaments) and in the limit of strong frictions we obtain a parabolic model which is a generalization of the standard Keller-Segel model describing the formation of clusters (clumps). Our approach connects and generalizes several models introduced in the chemotactic literature. We discuss the anal...

Chavanis, Pierre-Henri

2007-01-01T23:59:59.000Z

73

LANL | Physics | Hydrodynamic Material Instabilities at extremes  

NLE Websites -- All DOE Office Websites (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

74

Novel techniques for slurry bubble column hydrodynamics  

Science Conference Proceedings (OSTI)

The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research Engineering Company was to improve the knowledge base for scale-up and operation of slurry bubble column reactors for syngas conversion and other coal conversion processes by increased reliance on experimentally verified hydrodynamic models. During the first year (July 1, 1995--June 30, 1996) of this three year program novel experimental tools (computer aided radioactive particle tracking (CARPT), particle image velocimetry (PIV), heat probe, optical fiber probe and gamma ray tomography) were developed and tuned for measurement of pertinent hydrodynamic quantities, such as velocity field, holdup distribution, heat transfer and bubble size. The accomplishments were delineated in the First Technical Annual Report. The second year (July, 1996--June 30, 1997) was spent on further development and tuning of the novel experimental tools (e.g., development of Monte Carlo calibration for CARPT, optical probe development), building up the hydrodynamic data base using these tools and comparison of the two techniques (PIV and CARPT) for determination of liquid velocities. A phenomenological model for gas and liquid backmixing was also developed. All accomplishments were summarized in the Second Annual Technical Report. During the third and final year of the program (July 1, 1997--June 30, 1998) and during the nine months no cost extension, the high pressure facility was completed and a set of data was taken at high pressure conditions. Both PIV, CT and CARPT were used. More fundamental hydrodynamic modeling was also undertaken and model predictions were compared to data. The accomplishments for this period are summarized in this report.

Dudukovic, M.P.

1999-05-14T23:59:59.000Z

75

The Quantum Hydrodynamic Description of Tunneling  

SciTech Connect

The quantum hydrodynamic approach is based on the de Broglie-Bohm formulation of quantum mechanics. The resulting fluid-like equations of motion describe the flow of probability and an accurate solution to these equations is equivalent to solving the time-dependent Schroedinger equation. Furthermore, the hydrodynamic approach provides new insight into the mechanisms as well as an alternative computational approach for treating tunneling phenomena. New concepts include well-defined 'quantum trajectories', 'quantum potential', and 'quantum force' all of which have classical analogues. The quantum potential and its associated force give rise to all quantum mechanical effects such as zero point energy, tunneling, and interference. A new numerical approach called the Iterative Finite Difference Method (IFDM) will be discussed. The IFDM is used to solve the set of non-linear coupled hydrodynamic equations. It is 2nd-order accurate in both space and time and exhibits exponential convergence with respect to the iteration count. The stability and computational efficiency of the IFDM is significantly improved by using a 'smart' Eulerian grid which has the same computational advantages as a Lagrangian or Arbitrary Lagrangian Eulerian (ALE) grid. The IFDM is also capable of treating anharmonic potentials. Example calculations using the IFDM will be presented which include: a one-dimensional Gaussian wave packet tunneling through an Eckart barrier, a one-dimensional bound-state Morse oscillator, and a two-dimensional (2D) model collinear reaction using an anharmonic potential energy surface. Approximate treatments of the quantum hydrodynamic equations will also be discussed which could allow scaling of the calculations to hundreds of degrees of freedom which is important for treating tunneling phenomena in condensed phase systems.

Kendrick, Brian K. [Los Alamos National Laboratory

2012-06-15T23:59:59.000Z

76

Composite particle hydrodynamics from dyonic black branes  

E-Print Network (OSTI)

We construct an effective hydrodynamics of composite particles in three spacetime dimensions carrying magnetic flux, employing the holographic approach. The hydrodynamics can be obtained by considering the perturbation of dyonic black brane solutions in the derivative expansion. We consider two particular cases in more detail. In one case the gauge theory side is a Chern-Simon theory. This is enforced by assuming that the external current is the Poincare dual of the gauge field strength. Then the Hall conductivity is naturally incorporated and one can see the Hall momentum flow from the holographic energy-momentum tensor. For the other case we relax the aforementioned Chern-Simons condition for the external field. Then it turns out that the dual theory is a magnetohydrodynamics with an effective magnetic field which is shifted by external current. Both of these two hydrodynamics systems exhibit the behavior of composite particle systems. We also analyze the most general case, where we do not assume any relation between the charge density and the external magnetic field.

Kyung Kiu Kim; Nakwoo Kim; Yun-Long Zhang

2013-07-01T23:59:59.000Z

77

Hydrodynamic modes in a confined granular fluid  

E-Print Network (OSTI)

Confined granular fluids, placed in a shallow box that is vibrated vertically, can achieve homogeneous stationary states thanks to energy injection mechanisms that take place throughout the system. These states can be stable even at high densities and inelasticities allowing for a detailed analysis of the hydrodynamic modes that govern the dynamics of granular fluids. Analyzing the decay of the time correlation functions it is shown that there is a crossover between a quasielastic regime in which energy evolves as a slow mode, to a inelastic regime, with energy slaved to the other conserved fields. The two regimes have well differentiated transport properties and, in the inelastic regime, the dynamics can be described by a reduced hydrodynamics with modified longitudinal viscosity and sound speed. The crossover between the two regimes takes place at a wavevector that is proportional to the inelasticity. A two dimensional granular model, with collisions that mimic the energy transfers that take place in a confined system is studied by means of microscopic simulations. The results show excellent agreement with the theoretical framework and allows the validation of hydrodynamic-like models.

Ricardo Brito; Dino Risso; Rodrigo Soto

2013-01-17T23:59:59.000Z

78

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":""}]}

79

Thermowell and Radiographic Testing Plug Design Recommendations and Typical Practices  

Science Conference Proceedings (OSTI)

Thermowells and radiographic testing (RT) plugs are used universally in power generation plants. This Electric Power Research Institute (EPRI) report provides recommendations and explains the design and installation practices for these products that are common to the power industry. Numerous instances of thermowell failure are addressed and examined for the purposes of optimization.The report is intended to provide design, installation, and operation recommendations for power ...

2012-12-12T23:59:59.000Z

80

Dirac equation in terms of hydrodynamic variables  

E-Print Network (OSTI)

The distributed system $\\mathcal{S}_D$ described by the Dirac equation is investigated simply as a dynamic system, i.e. without usage of quantum principles. The Dirac equation is described in terms of hydrodynamic variables: 4-flux $j^{i}$, pseudo-vector of the spin $S^{i}$, an action $\\hbar \\phi $ and a pseudo-scalar $\\kappa $. In the quasi-uniform approximation, when all transversal derivatives (orthogonal to the flux vector $j^i$) are small, the system $\\mathcal{S}_D$ turns to a statistical ensemble of classical concentrated systems $\\mathcal{S}_{dc}$. Under some conditions the classical system $\\mathcal{S}_{dc}$ describes a classical pointlike particle moving in a given electromagnetic field. In general, the world line of the particle is a helix, even if the electromagnetic field is absent. Both dynamic systems $\\mathcal{S}_D$ and $\\mathcal{S}_{dc}$ appear to be non-relativistic in the sense that the dynamic equations written in terms of hydrodynamic variables are not relativistically covariant with respect to them, although all dynamic variables are tensors or pseudo-tensors. They becomes relativistically covariant only after addition of a constant unit timelike vector $f^{i}$ which should be considered as a dynamic variable describing a space-time property. This "constant" variable arises instead of $\\gamma $-matrices which are removed by means of zero divizors in the course of the transformation to hydrodynamic variables. It is possible to separate out dynamic variables $\\kappa $, $\\kappa ^i$ responsible for quantum effects. It means that, setting $\\kappa ,\\kappa ^i\\equiv 0$, the dynamic system $\\mathcal{S}_D$ described by the Dirac equation turns to a statistical ensemble $\\mathcal{E}_{Dqu}$ of classical dynamic systems $\\mathcal{S}_{dc}$.

Yuri A. Rylov

2011-01-31T23:59:59.000Z

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81

A hybrid Godunov method for radiation hydrodynamics  

Science Conference Proceedings (OSTI)

From a mathematical perspective, radiation hydrodynamics can be thought of as a system of hyperbolic balance laws with dual multiscale behavior (multiscale behavior associated with the hyperbolic wave speeds as well as multiscale behavior associated with source term relaxation). With this outlook in mind, this paper presents a hybrid Godunov method for one-dimensional radiation hydrodynamics that is uniformly well behaved from the photon free streaming (hyperbolic) limit through the weak equilibrium diffusion (parabolic) limit and to the strong equilibrium diffusion (hyperbolic) limit. Moreover, one finds that the technique preserves certain asymptotic limits. The method incorporates a backward Euler upwinding scheme for the radiation energy density E{sub r} and flux F{sub r} as well as a modified Godunov scheme for the material density {rho}, momentum density m, and energy density E. The backward Euler upwinding scheme is first-order accurate and uses an implicit HLLE flux function to temporally advance the radiation components according to the material flow scale. The modified Godunov scheme is second-order accurate and directly couples stiff source term effects to the hyperbolic structure of the system of balance laws. This Godunov technique is composed of a predictor step that is based on Duhamel's principle and a corrector step that is based on Picard iteration. The Godunov scheme is explicit on the material flow scale but is unsplit and fully couples matter and radiation without invoking a diffusion-type approximation for radiation hydrodynamics. This technique derives from earlier work by Miniati and Colella (2007) . Numerical tests demonstrate that the method is stable, robust, and accurate across various parameter regimes.

Sekora, Michael D., E-mail: sekora@math.princeton.ed [Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ 08544 (United States); Stone, James M. [Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ 08544 (United States); Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2010-09-20T23:59:59.000Z

82

Gas-liquid hydrodynamics in Taylor Flows with complex liquids.  

E-Print Network (OSTI)

??Universitá di Pisa Facoltá di Ingegneria Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali Relazione di tirocinio in Ingegneria Chimica Gas-liquid hydrodynamics in… (more)

ALBERINI, FEDERICO

2010-01-01T23:59:59.000Z

83

Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie...  

Open Energy Info (EERE)

Assessing Thermo-Hydrodynamic-Chemical Processes at the Dixie Valley Geothermal Area- A Reactive Transport Modeling Approach Jump to: navigation, search OpenEI Reference LibraryAdd...

84

Hydrodynamic Interactions of Two Micro-bubbles Due to an ...  

Science Conference Proceedings (OSTI)

Presentation Title, Hydrodynamic Interactions of Two Micro-bubbles Due to an ... A Review of Pyro, Hydro and Electro-metallurgical Processes for Recovering ...

85

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.

86

Optical and radiographical characterization of silica aerogel for Cherenkov radiator  

E-Print Network (OSTI)

We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.

Tabata, Makoto; Hatakeyama, Yoshikiyo; Kawai, Hideyuki; Morita, Takeshi; Nishikawa, Keiko

2012-01-01T23:59:59.000Z

87

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

88

Hydrodynamic orienting of asymmetric microobjects under gravity  

E-Print Network (OSTI)

It is shown that nonsymmetric microobjects orient while settling under gravity in a viscous fluid. To analyze this process, a simple shape is chosen: a non-deformable `chain'. The chain consists of two straight arms, made of touching solid spheres. In the absence of external torques, the spheres are free to spin along the arms. The motion of the chain is evaluated by solving the Stokes equations with the use of the multipole method. It is demonstrated that the spinning beads speed up sedimentation by a small amount, and increase the orientation rate significantly in comparison to the corresponding rigid chain. It is shown that chains orient towards the V-shaped stable stationary configuration. In contrast, rods and star-shaped microobjects do not rotate. The hydrodynamic orienting is relevant for efficient swimming of non-symmetric microobjects, and for sedimenting suspensions.

Maria L. Ekiel-Jezewska; Eligiusz Wajnryb

2008-12-12T23:59:59.000Z

89

Hydrodynamics of R-charged black holes  

E-Print Network (OSTI)

We consider hydrodynamics of N=4 supersymmetric SU(N_c) Yang-Mills plasma at a nonzero density of R-charge. In the regime of large N_c and large 't Hooft coupling the gravity dual description involves an asymptotically Anti- de Sitter five-dimensional charged black hole solution of Behrnd, Cvetic and Sabra. We compute the shear viscosity as a function of chemical potentials conjugated to the three U(1) \\subset SO(6)_R charges. The ratio of the shear viscosity to entropy density is independent of the chemical potentials and is equal to 1/4\\pi. For a single charge black hole we also compute the thermal conductivity, and investigate the critical behavior of the transport coefficients near the boundary of thermodynamic stability.

Dam T. Son; Andrei O. Starinets

2006-01-20T23:59:59.000Z

90

Hydrodynamics of a vertical hydraulic fracture  

DOE Green Energy (OSTI)

We have developed a numerical algorithm, HUBBERT, to simulate the hydrodynamics of a propagating vertical, rectangular fracture in an elastic porous medium. Based on the IFD method, this algorithm assumes fracture geometry to be prescribed. The breakdown and the creation of the incipient fracture is carried out according to the Hubbert-Willis theory. The propagation of the fracture is based on the criterion provided by Griffith, based on energy considerations. The deformation properties of the open fracture are based on simple elasticity solutions. The fracture is assumed to have an elliptical shape to a distance equal to the fracture height, beyond which the shape is assumed to be parallel plate. A consequence of Griffith's criterion is that the fracture must propagate in discrete steps. The parametric studies carried out suggest that for a clear understanding of the hydrodynamics of the hydraulic fracture many hitherto unrecognized parameters must be better understood. Among these parameters one might mention, efficiency, aperture of the newly formed fracture, stiffness of the newly formed fracture, relation between fracture aperture and permeability, and well bore compliance. The results of the studies indicate that the patterns of pressure transients and the magnitudes of fracture length appear to conform to field observations. In particular, the discrete nature of fracture propagation as well as the relevant time scales of interest inferred from the present work seem to be corroborated by seismic monitoring in the field. The results suggest that the estimation of least principal stress can be reliably made either with shut in data or with reinjection data provided that injection rates are very small.

Narasimhan, T.N.

1987-03-24T23:59:59.000Z

91

Scalable, hydrodynamic and radiation-hydrodynamic studies of neutron stars mergers  

Science Conference Proceedings (OSTI)

We discuss the high performance computing issues involved in the numerical simulation of binary neutron star mergers and supernovae. These phenomena, which are of great interest to astronomers and physicists, can only be described by modeling the gravitational ... Keywords: BiCG, Cray T3E, Silicon Graphics Origin 2000, astronomy, astrophysics, binary neutron stars, eulerian, fluid dynamics, gravitational field, hydrodynamics, iterative methods, linear systems, multidimensions, neutron star, parallel computing, precondition, radiation transport

F. Douglas Swesty; Paul Saylor; Dennis C. Smolarski; E. Y. M. Wang

1997-11-01T23:59:59.000Z

92

Analysis of the smoothed particle hydrodynamics method for free-surface flows  

E-Print Network (OSTI)

Smoothed Particle Hydrodynamics (SPH) is a simple and attractive meshless Lagrangian particle method with applications in many fields such as astrophysics, hydrodynamics, magnetohydrodynamics, gas explosions, and granular ...

Kiara, Areti

2010-01-01T23:59:59.000Z

93

Inhibition of Mild Steel Corrosion under Hydrodynamic Conditions  

Science Conference Proceedings (OSTI)

The inhibition of mild steel corrosion by 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) in 2.5 M H{sub 2}SO{sub 4} solution and the effect of hydrodynamic condition on inhibition process were studied. The hydrodynamic condition experiments are simulated by rotating cylinder electrode (RCE). Change of open circuit potential (OCP) with immersion time and potentiodynamic polarization were used to study the effect of hydrodynamic conditions on the inhibition process. Results obtained from changes of open circuit potential (OCP) with immersion time, and potentiodynamic polarization are in good agreement and indicated that the inhibition process was flow velocity dependence.

Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Takriff, Mohd Sobri; Kamarudin, Siti Kartom [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor (Malaysia); Daud, Abdul Razak [School of Applied Physics, Universiti Kebangsaan Malaysia, Bangi, 43600, Selangor (Malaysia)

2010-07-07T23:59:59.000Z

94

Working safely in gamma radiography. A training manual for industrial radiographers  

Science Conference Proceedings (OSTI)

This manual is designed for classroom training in working safely in industrial radiography using gamma sources. The purpose is to train radiographers' assistants to work safely as a qualified gamma radiographer. The contents cover the essentials of radiation, radiation protection, emergency procedures, gamma cameras, and biological effects of radiation. (ACR)

McGuire, S.A.; Peabody, C.A.

1982-09-01T23:59:59.000Z

95

Vacuum energy: quantum hydrodynamics vs quantum gravity  

E-Print Network (OSTI)

We compare quantum hydrodynamics and quantum gravity. They share many common features. In particular, both have quadratic divergences, and both lead to the problem of the vacuum energy, which in the quantum gravity transforms to the cosmological constant problem. We show that in quantum liquids the vacuum energy density is not determined by the quantum zero-point energy of the phonon modes. The energy density of the vacuum is much smaller and is determined by the classical macroscopic parameters of the liquid including the radius of the liquid droplet. In the same manner the cosmological constant is not determined by the zero-point energy of quantum fields. It is much smaller and is determined by the classical macroscopic parameters of the Universe dynamics: the Hubble radius, the Newton constant and the energy density of matter. The same may hold for the Higgs mass problem: the quadratically divergent quantum correction to the Higgs potential mass term is also cancelled by the microscopic (trans-Planckian) degrees of freedom due to thermodynamic stability of the whole quantum vacuum.

G. E. Volovik

2005-05-20T23:59:59.000Z

96

Energy Gradient Theory of Hydrodynamic Instability  

E-Print Network (OSTI)

A new universal theory for flow instability and turbulent transition is proposed in this study. Flow instability and turbulence transition have been challenging subjects for fluid dynamics for a century. The critical condition of turbulent transition from theory and experiments differs largely from each other for Poiseuille flows. In this paper, a new mechanism of flow instability and turbulence transition is presented for parallel shear flows and the energy gradient theory of hydrodynamic instability is proposed. It is stated that the total energy gradient in the transverse direction and that in the streamwise direction of the main flow dominate the disturbance amplification or decay. A new dimensionless parameter K for characterizing flow instability is proposed for wall bounded shear flows, which is expressed as the ratio of the energy gradients in the two directions. It is thought that flow instability should first occur at the position of Kmax which may be the most dangerous position. This speculation is confirmed by Nishioka et al's experimental data. Comparison with experimental data for plane Poiseuille flow and pipe Poiseuille flow indicates that the proposed idea is really valid. It is found that the turbulence transition takes place at a critical value of Kmax of about 385 for both plane Poiseuille flow and pipe Poiseuille flow, below which no turbulence will occur regardless the disturbance. More studies show that the theory is also valid for plane Couette flows and Taylor-Couette flows between concentric rotating cylinders.

Hua-Shu Dou

2005-01-28T23:59:59.000Z

97

The hydrodynamics of dead radio galaxies  

E-Print Network (OSTI)

We present a numerical investigation of dead, or relic, radio galaxies and the environmental impact that radio galaxy activity has on the host galaxy or galaxy cluster. We perform axisymmetric hydrodynamical calculations of light, supersonic, back-to-back jets propagating in a beta-model galaxy/cluster atmosphere. We then shut down the jet activity and let the resulting structure evolve passively. The dead source undergoes an initial phase of pressure driven expansion until it achieves pressure equilibrium with its surroundings. Thereafter, buoyancy forces drive the evolution and lead to the formation of two oppositely directed plumes that float high into the galaxy/cluster atmosphere. These plumes entrain a significant amount of low entropy material from the galaxy/cluster core and lift it high into the atmosphere. An important result is that a large fraction (at least half) of the energy injected by the jet activity is thermalized in the ISM/ICM core. The whole ISM/ICM atmosphere inflates in order to regain hydrostatic equilibrium. This inflation is mediated by an approximately spherical disturbance which propagates into the atmosphere at the sound speed. The fact that such a large fraction of the injected energy is thermalized suggests that radio galaxies may have an important role in the overall energy budget of rich ISM/ICM atmospheres. In particular, they may act as a strong and highly time-dependent source of negative feedback for galaxy/cluster cooling flows.

C. S. Reynolds; S. Heinz; M. C. Begelman

2002-01-16T23:59:59.000Z

98

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 +

99

Modeling of nearshore hydrodynamics for sediment transport calculations  

E-Print Network (OSTI)

This thesis analyzes and improves Tajima's (2004) nearshore hydrodynamic model. Tajima's simple model accurately predicts long-shore sediment transport along long, straight beaches, while cross-shore transport predictions ...

Gonzalez-Rodriguez, David, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

100

The new computer program for three dimensional relativistic hydrodynamical model  

E-Print Network (OSTI)

An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.

Daniel Kikola; Wiktor Peryt; Yuri M. Sinyukov; Marcin Slodkowski; Marek Szuba

2006-01-30T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

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

102

Page not found | Department of Energy  

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

91 - 6800 of 9,640 results. 91 - 6800 of 9,640 results. Download Audit Report: IG-0415 Audit of Departmental Receipt of Final Deliverables for Grant Awards http://energy.gov/ig/downloads/audit-report-ig-0415 Download Special Report: IG-0538 Management Challenges at the Department of Energy http://energy.gov/ig/downloads/special-report-ig-0538 Download Semiannual Report to Congress: October 1, 2007- March 31, 2008 Semiannual Report to Congress, October 1, 2007 - March 31, 2008 http://energy.gov/ig/downloads/semiannual-report-congress-october-1-2007-march-31-2008 Download Audit Report: IG-0814 The Procurement of Safety Class/Safety-Significant Items at the Savannah River Site http://energy.gov/ig/downloads/audit-report-ig-0814 Download EIS-0228: Record of Decision Dual Axis Radiographic Hydrodynamic Test Facility

103

Microsoft Word - Defense Science Quarterly 08-08.doc  

National Nuclear Security Administration (NNSA)

August 2008 August 2008 Defense Science Quarterly Inside This Issue 1 Message from the Director 2 Derivative Applications of Pulsed Power Science and Technology 4 LANSCE-R Means More Beam for National Security Research 6 Dual Axis Radiographic Hydrodynamics Test (DARHT) 2 nd Axis Completed and Put into Operation 7 Annual Symposium of the Stewardship Science Graduate Fellowship Program 8 Publication Highlights 9 ICOPS 2008 9 Highlights and Awards Message from the Director Chris Deeney, Defense Science Division It's hard to believe it's been a year since we published our first issue of the Defense Science Quarterly. I would like to express my appreciation to all the authors who have submitted articles and to the production staff. If you are

104

Dynamic Vision: 1663 Science and Technology Magazine | Los National Alamos  

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

1663 banner 1663 banner Current Issue Past Issues Contacts November, 2009. Wendy Vogan McNeil stood in the control room of the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility as the machine operators began their countdown for experiment H3837. McNeil and fellow experimenters Matthew Briggs and Lawrence Hull had spent about 10 months preparing for this moment. They had chosen the target material-a newly developed alloy-and had it fashioned into a miniature hockey puck that McNeil later set atop 31 grams of high explosive. They calculated that once the explosive detonated, it would take about 8 millionths of a second (8 microseconds) for a shock wave to reach the puck, rush through it, and begin to blow the top surface off. A computer simulation predicted how much the alloy would be compressed

105

NEPA Lessons Learned Quarterly Report - 2nd Quarter FY 1999  

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

June 1999 June 1999 1 LESSONS LEARNED LEARNED LESSONS National Environmental Policy Act N E P A U.S. DEPARTMENT OF ENERGY QUARTERLY REPORT For Second Quarter FY 1999 June 1, 1999; Issue No. 19 continued on page 6 NEPA and Habitat Management Plan: Environmental Synergy By: Elizabeth Withers, NEPA Compliance Officer, Los Alamos Area Office, with John Stetson, Pacific Western Technologies, Ltd. On the day DOE issued the Draft EIS for the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory (LANL), LANL biologists discovered a nesting pair of Mexican spotted owls (Strix occidentalis lucida) – which had only recently been listed as threatened – in the canyons directly below the proposed site. Today, this nest site, at the edge

106

Los Alamos National Laboratory to begin DARHT 2 operations  

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

January » January » DARHT 2 operations begin Los Alamos National Laboratory to begin DARHT 2 operations The Dual Axis Radiographic Hydrodynamic Test facility has officially become "dual" with authorization to begin full power operations of Axis 2. January 29, 2008 DARHT's electron accelerators use large, circular aluminum structures to create magnetic fields that focus and steer a stream of electrons down the length of the accelerator. Tremendous electrical energy is added along the way. When the stream of high-speed electrons exits the accelerator it is "stopped" by a tungsten target resulting in an intense burst of X-rays that are used to create digital images of mock nuclear devices as they implode. DARHT's electron accelerators use large, circular aluminum structures to

107

NNSA's Summary of Experiments Conducted in Support of Stockpile  

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

for the 1st quarter of FY2012 prepared by NNSA's for the 1st quarter of FY2012 prepared by NNSA's Office of Defense Programs provides descriptions of key NNSA facilities that conduct stockpile stewardship experiments. These include some of the most sophisticated scientific research facilities in the world including, the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory, National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, and the Z machine at Sandia National Laboratories. The summary also provides the number of experiments performed at each facility during each quarter of the fiscal year. The U.S. Stockpile Stewardship Program is a robust program of scientific inquiry used to sustain and assess the nuclear weapons stockpile without the use of underground nuclear tests. The experiments carried out within

108

NNSA's Summary of Experiments Conducted in Support of Stockpile  

National Nuclear Security Administration (NNSA)

for the 1st quarter of FY2012 prepared by NNSA's for the 1st quarter of FY2012 prepared by NNSA's Office of Defense Programs provides descriptions of key NNSA facilities that conduct stockpile stewardship experiments. These include some of the most sophisticated scientific research facilities in the world including, the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory, National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, and the Z machine at Sandia National Laboratories. The summary also provides the number of experiments performed at each facility during each quarter of the fiscal year. The U.S. Stockpile Stewardship Program is a robust program of scientific inquiry used to sustain and assess the nuclear weapons stockpile without the use of underground nuclear tests. The experiments carried out within

109

Lessons Learned Quarterly Report, December 1995 | Department of Energy  

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

December 1995 December 1995 Lessons Learned Quarterly Report, December 1995 This quarterly report summarizes the lessons learned for documents completed between July 1 and September 30, 1995. It is based primarily on responses to the revised questionnaire that was provided for use during January 1995, and includes information on direct and indirect NEPA process costs and on total project costs. Included in this issue: NEPA Document Preparation Times NEPA Cost Date NEPA Document Content The Document Preparation Process Effectiveness of the NEPA Process Other Lessons Learned Feature Stories Waste Isolation Pilot Plant Supplemental EIS Dual Axis Radiographic Hydrodynamic Test Facility EIS Updates from the Office of NEPA Policy and Assistance The Need for Consistency in Accident Analyses

110

Design considerations for a time-resolved tomographic diagnostic at DARHT  

Science Conference Proceedings (OSTI)

An instrument has been developed to acquire time-resolved tomographic data from the electron beam at the DARHT [Dual-Axis Radiographic Hydrodynamic Test] facility at Los Alamos National Laboratory. The instrument contains four optical lines of sight that view a single tilted object. The lens design optically integrates along one optical axis for each line of sight. These images are relayed via fiber optic arrays to streak cameras, and the recorded streaks are used to reconstruct the original two-dimensional data. Installation of this instrument into the facility requires automation of both the optomechanical adjustments and calibration of the instrument in a constrained space. Additional design considerations include compound tilts on the object and image planes.

Morris I. Kaufman, Daniel Frayer, Wendi Dreesen, Douglas Johnson, Alfred Meidinger

2006-08-01T23:59:59.000Z

111

Environmental Impact Statements (EIS) | Department of Energy  

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

October 1, 1995 October 1, 1995 EIS-0245: Draft Environmental Impact Statement Management of Spent Nuclear Fuel from the K Basins at the Hanford Site, Richland, Washington July 21, 1995 EIS-0182: Final Programmatic Environmental Impact Statement Energy Planning And Management Program July 1, 1995 EIS-0217: Final Environmental Impact Statement Savannah River Site Waste Management May 1, 1995 EIS-0228: Final Environmental Impact Statement Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility April 1, 1995 EIS-0203: Programmatic Final Environmental Impact Statement Spent Nuclear Fuel Management and Idaho National Engineering Laboratory Environmental Restoration and Waste Management Programs January 1, 1995 EIS-0220: Final Environmental Impact Statement Savannah River Site, Interim Management of Nuclear Materials

112

Exposure to ionizing radiation in the emergency department from commonly performed portable radiographs  

SciTech Connect

To accurately assess the potential hazard of exposure to ionizing radiation from portable radiographs taken in the emergency department, a study was performed to measure such radiation at different distances from the edge of an irradiated field during portable cervical-spine (pC-S), portable chest radiograph (pCXR), and portable anteroposterior-pelvis (pAP-pelvis) radiographs. For all three types of portable radiographs, radiation exposure is a function of distance from the beam. However, at 40 cm (15 inches) away from the beam during a pC-S or pCXR and at 160 cm (63 inches) from a pAP-pelvis film, exposure is minimal. At these distances one would need to be exposed to more than 1,200 such radiographs to equal background environmental ionizing radiation. Medical personnel should not have to leave a patient care area for fear of undue acute and chronic radiation exposure while portable radiographs are performed in the ED. By using protective garments and standing appropriate distances away from the patient, continuous patient care can be maintained while portable radiographs are taken in the ED.

Grazer, R.E.; Meislin, H.W.; Westerman, B.R.; Criss, E.A.

1987-04-01T23:59:59.000Z

113

Absorbed dose measurements during routine equine radiographic procedures  

E-Print Network (OSTI)

This study was performed in order to determine absorbed doses from scattered radiation to personnel during routine equine radiographic procedures and to determine if the protective apparel adequately reduced exposure from scattered radiation. Absorbed doses were measured for one month at the Texas A&M University Veterinary Teaching Hospital using Li:Mg,Cu,P thermoluminescent dosimeters (TLDs). All personnel present in the x-ray examination room during eqine radiography were monitored using TLDs placed at: (1) the finger level; (2) the waist level; (3) the eye level; and (4) the forearm level. Absorbed doses ranged from 0.693 ligy to 31.3 tigy per study. The greatest doses were associated with the individual handling the cassette holder, although the individual making the exposures received similar doses due to improper techniques. The individual holding the horse's halter consistently received the lowest dose. Although all doses observed were within acceptable limits for occupational workers, results demonstrated the need for protective apparel to effectively reduce exposures.

Salinas, Leticia Lamar

1996-01-01T23:59:59.000Z

114

Method for producing three-dimensional real image using radiographic perspective views of an object  

DOE Patents (OSTI)

A sequence of separate radiographs are made by indexing a radiation source along a known path relative to the object under study. Thus, each radiograph contains information from a different perspective. A holographically-recorded image is then made from each radiographic perspective by exact re-tracing of the rays through each radiographic perspective such that the re-tracing duplicates the geometry under which it was originally prepared. The holographically-stored images are simultaneously illuminated with the conjugate of the reference beam used in the original recordings. The result is the generation of a three-dimensional real image of the object such that a light-sensitive device can be moved to view the real image along any desired surface with the optical information in all other surfaces greatly suppressed.

Ellingson, William A. (Ames, IA); Read, Alvin A. (Ames, IA)

1976-02-24T23:59:59.000Z

115

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":""}]}

116

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

117

Nondestructive Evaluation: CIVA Software Comparisons for Eddy Current and Radiographic Techniques  

Science Conference Proceedings (OSTI)

This report documents the status of an independent validation of the French Alternative Energies and Atomic Energy Commission’s (CEA’s) CIVA1 simulation software for eddy current and radiographic inspections performed by the Electric Power Research Institute (EPRI). A general overview of the CIVA program simulation capability and process is presented with respect to eddy current testing and radiographic testing, along with some comparisons between experimental and ...

2012-11-29T23:59:59.000Z

118

New models for region of interest reader classification analysis in chest radiographs  

Science Conference Proceedings (OSTI)

In several computer-aided diagnosis (CAD) applications of image processing, there is no sufficiently sensitive and specific method for determining what constitutes a normal versus an abnormal classification of a chest radiograph. In the case of lung ... Keywords: 10.-v, 75.Pq, 87.85.Tu, Binary classification, Chest radiographs, Logic, set theory, and algebra, Mathematical procedures and computer techniques, Modeling biomedical systems, Pneumoconiosis, ROC analysis, Region of interest classification

M. S. Pattichis; T. Cacoullos; Peter Soliz

2009-06-01T23:59:59.000Z

119

3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK  

SciTech Connect

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

120

Does Fluctuating Nonlinear Hydrodynamics Support an Ergodic-Nonergodic Transition?  

E-Print Network (OSTI)

Despite its appeal, real and simulated glass forming systems do not undergo an ergodic-nonergodic (ENE) transition. We reconsider whether the fluctuating nonlinear hydrodynamics (FNH) model for this system, introduced by us in 1986, supports an ENE transition. Using nonperturbative arguments, with no reference to the hydrodynamic regime, we show that the FNH model does not support an ENE transition. Our results support the findings in the original paper. Assertions in the literature questioning the validity of the original work are shown to be in error.

Shankar P. Das; Gene F. Mazenko

2008-01-11T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Relativistic hydrodynamics, heavy ion reactions and antiproton annihilation  

SciTech Connect

The application of relativistic hydrodynamics to relativistic heavy ions and antiproton annihilation is summarized. Conditions for validity of hydrodynamics are presented. Theoretical results for inclusive particle spectra, pion production and flow analysis are given for medium energy heavy ions. The two-fluid model is introduced and results presented for reactions from 800 MeV per nucleon to 15 GeV on 15 GeV per nucleon. Temperatures and densities attained in antiproton annihilation are given. Finally, signals which might indicate the presence of a quark-gluon plasma are briefly surveyed.

Strottman, D.

1985-01-01T23:59:59.000Z

122

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

123

Non-dissipative hydrodynamics: Effective actions versus entropy current  

E-Print Network (OSTI)

While conventional hydrodynamics incorporating dissipative effects is hard to derive from an action principle, it is nevertheless possible to construct classical actions when the dissipative terms are switched off. In this note we undertake a systematic exploration of such constructions from an effective field theory approach and argue for the existence of non-trivial second order non-dissipative hydrodynamics involving pure energy-momentum transport. We find these fluids to be characterized by five second-order transport coefficients based on the effective action (a three parameter family is Weyl invariant). On the other hand since all flows of such fluids are non-dissipative, they entail zero entropy production; one can therefore understand them using the entropy current formalism which has provided much insight into hydrodynamic transport. An analysis of the most general stress tensor with zero entropy production however turns out to give a seven parameter family of non-dissipative hydrodynamics (a four parameter sub-family being Weyl invariant). The non-dissipative fluids derived from the effective action approach are a special case of the fluid dynamics constrained by conservation of the entropy current. We speculate on the reasons for the mismatch and potential limitations of the effective action approach.

Jyotirmoy Bhattacharya; Sayantani Bhattacharyya; Mukund Rangamani

2012-11-05T23:59:59.000Z

124

Improved ADCP Performance Using a Hydrodynamically Designed Boom Mount  

Science Conference Proceedings (OSTI)

This paper presents the results of the design and testing of a hydrodynamic mount for a direct-reading 150-kHz acoustic Doppler current profiler (ADCP) operated over the side of a small inshore vessel in transect mode (i.e., while steaming). The ...

E. B. Colbourne; J. Helbig; D. Cumming

1993-08-01T23:59:59.000Z

125

Shock propagation and stability in causal dissipative hydrodynamics  

E-Print Network (OSTI)

We studied the shock propagation and its stability with the causal dissipative hydrodynamics in 1+1 dimensional systems. We show that the presence of the usual viscosity is not enough to stabilize the solution. This problem is solved by introducing an additional viscosity which is related to the coarse-graining scale of the theory.

G. S. Denicol; T. Kodama; T. Koide; Ph. Mota

2008-05-12T23:59:59.000Z

126

Study on Hydrodynamic Outline of an Unmanned Underwater Vehicle  

Science Conference Proceedings (OSTI)

Unmanned Underwater Vehicle (UUV) is being widely developed and used in many areas. In order to meet the low resistance and low noise requirements of a kind of UUV for long voyage, the outline curve and parameters of different sections of the UUV are ... Keywords: Unmanned underwater vehicle, Hydrodynamic outline, Low resistance, Low noise

Shao Zhiyu, Fang Jing, Feng Shunshan, Cheng Yufeng

2013-01-01T23:59:59.000Z

127

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

SciTech Connect

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

128

A direct Eulerian GRP scheme for relativistic hydrodynamics: One-dimensional case  

Science Conference Proceedings (OSTI)

The paper proposes a direct Eulerian generalized Riemann problem (GRP) scheme for one-dimensional relativistic hydrodynamics. It is an extension of the Eulerian GRP scheme for compressible non-relativistic hydrodynamics proposed in [M. Ben-Artzi, J.Q. ... Keywords: Characteristic coordinate, Godunov scheme, Rankine-Hugoniot jump condition, Relativistic hydrodynamics, Riemann invariant, The generalized Riemann problem scheme

Zhicheng Yang; Peng He; Huazhong Tang

2011-09-01T23:59:59.000Z

129

Standard practice for radiographic examination of advanced aero and turbine materials and components  

E-Print Network (OSTI)

1.1 This practice establishes the minimum requirements for radiographic examination of metallic and nonmetallic materials and components used in designated applications such as gas turbine engines and flight structures. 1.2 The requirements in this practice are intended to control the radiographic process to ensure the quality of radiographic images produced for use in designated applications such as gas turbine engines and flight structures; this practice is not intended to establish acceptance criteria for material or components. When examination is performed in accordance with this practice, engineering drawings, specifications or other applicable documents shall indicate the acceptance criteria. 1.3 All areas of this practice may be open to agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respons...

American Society for Testing and Materials. Philadelphia

2009-01-01T23:59:59.000Z

130

Development and Implementation of Radiation-Hydrodynamics Verification Test Problems  

SciTech Connect

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

131

Hydrodynamic granular segregation induced by boundary heating and shear  

E-Print Network (OSTI)

Segregation induced by a thermal gradient of an impurity in a driven low-density granular gas is studied. The system is enclosed between two parallel walls from which we input thermal energy to the gas. We study here steady states occurring when the inelastic cooling is exactly balanced by some external energy input (stochastic force or viscous heating), resulting in a uniform heat flux. A segregation criterion based on Navier-Stokes granular hydrodynamics is written in terms of the tracer diffusion transport coefficients, whose dependence on the parameters of the system (masses, sizes and coefficients of restitution) is explicitly determined from a solution of the inelastic Boltzmann equation. The theoretical predictions are validated by means of Monte Carlo and molecular dynamics simulations, showing that Navier-Stokes hydrodynamics produces accurate segregation criteria even under strong shearing and/or inelasticity.

Francisco Vega Reyes; Vicente Garzó; Nagi Khalil

2013-10-02T23:59:59.000Z

132

Simulation of Tailrace Hydrodynamics Using Computational Fluid Dynamics Models  

DOE Green Energy (OSTI)

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

Cook, Chris B; Richmond, Marshall C

2001-05-01T23:59:59.000Z

133

Hydrodynamic effect in a tank containing two liquids  

Science Conference Proceedings (OSTI)

Liquid Metal Reactor (LMR) research based on the Integral Fast Reactor (IFR) concept is currently underway at Argonne National Laboratory (ANL). One of the key features in the IFR concept is the closed fissile self-sufficient fuel cycle using pyrometallurgical processing and injection-casting to refabricate recycled fuels (Burris et al. 1987). The pyrometallurgical process is carried out primarily in a tank called the electrorefiner which contains two liquids with different mass densities. This tank should be properly designed to survive the earthquake to which it may be subjected; therefore, it is important to understand the hydrodynamic seduced in the tank during the seismic event in order to compute the corresponding stresses accurately. This paper deals with the hydrodynamic response of the electrorefiner to a given design earthquake. Both analytical and numerical (FEM) methods are employed in the analysis. The tank is assumed to be rigid, and the response is considered to be linear.

Tang, Y.

1993-08-01T23:59:59.000Z

134

Neutrino signature of supernova hydrodynamical instabilities in three dimensions  

E-Print Network (OSTI)

The first full-scale three-dimensional (3D) core-collapse supernova (SN) simulations with sophisticated neutrino transport show pronounced effects of the standing accretion shock instability (SASI) for two high-mass progenitors (20 and 27 M_sun). In a low-mass progenitor (11.2 M_sun), large-scale convection is the dominant nonradial hydrodynamic instability in the postshock accretion layer. The SASI-associated modulation of the neutrino signal (80 Hz in our two examples) will be clearly detectable in IceCube or the future Hyper-Kamiokande detector, depending on progenitor properties, distance, and observer location relative to the main SASI sloshing direction. The neutrino signal from the next galactic SN can therefore diagnose the nature of the hydrodynamic instability.

Irene Tamborra; Florian Hanke; Bernhard Mueller; Hans-Thomas Janka; Georg Raffelt

2013-07-30T23:59:59.000Z

135

Hydrodynamic design loads for the OTEC cold water pipe  

DOE Green Energy (OSTI)

Ocean current and/or plant motion crossflows induce time dependent hydrodynamic loads on the OTEC cold water pipe due to vortex shedding. Design criteria were established for mean and fluctuating loads based on a review of the literature, analysis of test data acquired by SAI under a previous experimental program and an analytical extension of test results to higher Reynolds number. Baseline loads were specified for rigid cylinders in uniform flows. Modifications to the loads by current shear, stratification and cylinder motion, were investigated and final design criteria established. Limited structural response calculations were performed to demonstrate the use of the design criteria and to investigate briefly the possible structural response mode. Comparisons were made with alternate hydrodynamic loads, and recommendations were made for experimental verification.

Hove, D.; Shih, W.; Albano, E.

1978-09-01T23:59:59.000Z

136

Enhanced Heat Flow in the Hydrodynamic Collisionless Regime  

SciTech Connect

We study the heat conduction of a cold, thermal cloud in a highly asymmetric trap. The cloud is axially hydrodynamic, but due to the asymmetric trap radially collisionless. By locally heating the cloud we excite a thermal dipole mode and measure its oscillation frequency and damping rate. We find an unexpectedly large heat conduction compared to the homogeneous case. The enhanced heat conduction in this regime is partially caused by atoms with a high angular momentum spiraling in trajectories around the core of the cloud. Since atoms in these trajectories are almost collisionless they strongly contribute to the heat transfer. We observe a second, oscillating hydrodynamic mode, which we identify as a standing wave sound mode.

Meppelink, R.; Rooij, R. van; Vogels, J. M.; Straten, P. van der [Atom Optics and Ultrafast Dynamics, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

2009-08-28T23:59:59.000Z

137

Soft Photons from transport and hydrodynamics at FAIR energies  

E-Print Network (OSTI)

Direct photon spectra from uranium-uranium collisions at FAIR energies (E(lab) = 35 AGeV) are calculated within the hadronic Ultra-relativistic Quantum Molecular Dynamics transport model. In this microscopic model, one can optionally include a macroscopic intermediate hydrodynamic phase. The hot and dense stage of the collision is then modeled by a hydrodynamical calculation. Photon emission from transport-hydro hybrid calculations is examined for purely hadronic matter and matter that has a cross-over phase transition and a critical end point to deconfined and chirally restored matter at high temperatures. We find the photon spectra in both scenarios to be dominated by Bremsstrahlung. Comparing flow of photons in both cases suggests a way to distinguish these two scenarios.

Andreas Grimm; Bjørn Bäuchle

2012-11-11T23:59:59.000Z

138

Skew and twist resistant hydrodynamic rotary shaft seal  

DOE Patents (OSTI)

A hydrodynamically lubricated squeeze packing type rotary shaft seal suitable for lubricant retention and environmental exclusion which incorporates one or more resilient protuberances which cooperate with the gland walls to hold the seal straight in its installation groove in unpressurized and low pressure lubricant retention applications thereby preventing skew-induced wear caused by impingement of abrasive contaminants present in the environment, and which also serve as radial bearings to prevent tipping of the seal within its installation gland. 14 figs.

Dietle, L.; Kalsi, M.S.

1999-02-23T23:59:59.000Z

139

Skew and twist resistant hydrodynamic rotary shaft seal  

DOE Patents (OSTI)

A hydrodynamically lubricated squeeze packing type rotary shaft seal suitable for lubricant retention and environmental exclusion which incorporates one or more resilient protuberances which and cooperate with the gland walls to hold the seal straight in its installation groove in unpressurized and low pressure lubricant retention applications thereby preventing skew-induced wear caused by impingement of abrasive contaminants present in the environment, and which also serve as radial bearings to prevent tipping of the seal within its installation gland.

Dietle, Lannie (Sugar Land, TX); Kalsi, Manmohan Singh (Houston, TX)

1999-01-01T23:59:59.000Z

140

Chest radiographs obtained with shaped filters: evaluation by observer performance tests  

SciTech Connect

The effectiveness of a shaped filter in improving nodule and infiltrate detection was measured by observer performance testing. Seven observers read 152 test radiographs of the chest obtained from human volunteers. Half the test radiographs had target image observer performance in detecting nodule or infiltrate images was compared with the shaped-filter system and with a conventional chest imaging system. The results were analyzed using receiver operating characteristic (ROC) techniques and indicate that the filter technique was not significantly different from the conventional technique in infiltrate depiction. Observer performance in detecting nodules was slightly worse on images obtained with the shaped-filter system.

Kelsey, C.A.; Lane, R.G.; Moseley, R.D.; Mettler, F.A.; Rosenberg, R.D.; Williams, A.G.; Garcia, J.F.; Feldman, B.S.; Boardman, R.E.

1986-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Hydrodynamically Lubricated Rotary Shaft Having Twist Resistant Geometry  

SciTech Connect

A hydrodynamically lubricated squeeze packing type rotary shaft with a cross-sectional geometry suitable for pressurized lubricant retention is provided which, in the preferred embodiment, incorporates a protuberant static sealing interface that, compared to prior art, dramatically improves the exclusionary action of the dynamic sealing interface in low pressure and unpressurized applications by achieving symmetrical deformation of the seal at the static and dynamic sealing interfaces. In abrasive environments, the improved exclusionary action results in a dramatic reduction of seal and shaft wear, compared to prior art, and provides a significant increase in seal life. The invention also increases seal life by making higher levels of initial compression possible, compared to prior art, without compromising hydrodynamic lubrication; this added compression makes the seal more tolerant of compression set, abrasive wear, mechanical misalignment, dynamic runout, and manufacturing tolerances, and also makes hydrodynamic seals with smaller cross-sections more practical. In alternate embodiments, the benefits enumerated above are achieved by cooperative configurations of the seal and the gland which achieve symmetrical deformation of the seal at the static and dynamic sealing interfaces. The seal may also be configured such that predetermined radial compression deforms it to a desired operative configuration, even through symmetrical deformation is lacking.

Dietle, Lannie (Houston, TX); Gobeli, Jeffrey D. (Houston, TX)

1993-07-27T23:59:59.000Z

142

RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code  

SciTech Connect

The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.

Zhang, Wei-Qun; /KIPAC, Menlo Park; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study

2005-06-06T23:59:59.000Z

143

Dancing Volvox: Hydrodynamic Bound States of Swimming Algae  

E-Print Network (OSTI)

The spherical alga Volvox swims by means of flagella on thousands of surface somatic cells. This geometry and its large size make it a model organism for studying the fluid dynamics of multicellularity. Remarkably, when two nearby Volvox swim close to a solid surface, they attract one another and can form stable bound states in which they "waltz" or "minuet" around each other. A surface-mediated hydrodynamic attraction combined with lubrication forces between spinning, bottom-heavy Volvox explains the formation, stability and dynamics of the bound states. These phenomena are suggested to underlie observed clustering of Volvox at surfaces.

Knut Drescher; Kyriacos C. Leptos; Idan Tuval; Takuji Ishikawa; Timothy J. Pedley; Raymond E. Goldstein

2009-01-14T23:59:59.000Z

144

Skew And Twist Resistant Hydrodynamic Rotary Shaft Seal  

SciTech Connect

A hydrodynamically lubricated squeeze packing type rotary shaft seal suitable for lubricant retention and environmental exclusion which incorporates one or more resilient protuberances which and cooperate with the gland walls to hold the seal straight in its installation groove in unpressurized and low pressure lubricant retention applications thereby preventing skew-induced wear caused by impingement of abrasive contaminants present in the environment, and which also serve as radial bearings to prevent tipping of the seal within its installation gland. Compared to prior art, this invention provides a dramatic reduction of seal and shaft wear in abrasive environments and provides a significant increase in seal life.

Dietle, Lannie (Sugar Land, TX); Kalsi, Manmohan Singh (Houston, TX)

2000-03-14T23:59:59.000Z

145

Non-linear hydrodynamics of incommensurate intergrowth compounds and quasicrystals  

E-Print Network (OSTI)

Hamiltonian structures for non-linear hydrodynamics of incommensurate intergrowth compounds (IIC) and quasicrystals (IQ) are constructed. We discuss also the way to account for internal friction of phason nature. We show that the existence of a self-force in IIC and IQ is not only matter of constitutive issues, rather it is related with questions of SO(3) invariance. The covariant mechanics of discontinuity surfaces in quasiperiodic structures is also analyzed. The attention is mainly focused on the interaction between `diffuse' grain boundaries and sharp discontinuity (moving possibly) surfaces.

Paolo Maria Mariano

2004-07-16T23:59:59.000Z

146

Electron magneto-hydrodynamic waves bounded by magnetic bubble  

Science Conference Proceedings (OSTI)

The propagation of electron magneto-hydrodynamic (EMHD) waves is studied experimentally in a 3-dimensional region of low magnetic field surrounded by stronger magnetic field at its boundaries. We report observations where bounded left hand polarized Helicon like EMHD waves are excited, localized in the region of low magnetic field due to the boundary effects generated by growing strengths of the ambient magnetic field rather than a conducting or dielectric material boundary. An analytical model is developed to include the effects of radially nonuniform magnetic field in the wave propagation. The bounded solutions are compared with the experimentally obtained radial wave magnetic field profiles explaining the observed localized propagation of waves.

Anitha, V. P.; Sharma, D.; Banerjee, S. P.; Mattoo, S. K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2012-08-15T23:59:59.000Z

147

Role of Brownian Motion Hydrodynamics on Nanofluid Thermal Conductivity  

Science Conference Proceedings (OSTI)

We use a simple kinetic theory based analysis of heat flow in fluid suspensions of solid nanoparticles (nanofluids) to demonstrate that the hydrodynamics effects associated with Brownian motion have a minor effect on the thermal conductivity of the nanofluid. Our conjecture is supported by the results of molecular dynamics simulations of heat flow in a model nanofluid with well-dispersed particles. Our findings are consistent with the predictions of the effective medium theory as well as with recent experimental results on well dispersed metal nanoparticle suspensions.

W Evans, J Fish, P Keblinski

2005-11-14T23:59:59.000Z

148

Wake II model for hydrodynamic forces on marine pipelines for the wave plus current case.  

E-Print Network (OSTI)

??The concept of the Wake II model for the determination of the hydrodynamic forces on marine pipelines is extended to include the wave plus current… (more)

Ramirez Sabag, Said

2012-01-01T23:59:59.000Z

149

Coupled 3D hydrodynamic models for submarine outfalls. Denvironmental hydraulic design and control of multiport diffusers.  

E-Print Network (OSTI)

??The book describes the hydraulic design and environmental impact prediction technologies for such installations. Focus are the hydrodynamics approached by computer models. First, a multiport… (more)

Bleninger, Tobias

2007-01-01T23:59:59.000Z

150

Dissipative hydrodynamic evolution of hot quark matter at finite baryon density  

E-Print Network (OSTI)

High-energy heavy ion collider experiments at RHIC and LHC have revealed that relativistic hydrodynamic models describe the hot and dense quark matter quantitatively. In this study, I develop a novel dissipative hydrodynamic model at finite baryon density to investigate the net baryon rapidity distribution. The results show that the distribution is widened in hydrodynamic evolution, which implies that the transparency of the collisions is effectively enhanced. This suggests that the kinetic energy loss for medium production at the initial stage could be larger. Furthermore, the net baryon distribution is found sensitive to baryon diffusion, implying that dissipative hydrodynamic modeling would be important for understanding the hot medium.

Monnai, Akihiko

2013-01-01T23:59:59.000Z

151

DARHT Axis-I Diode Simulations II: Geometrical Scaling  

SciTech Connect

Flash radiography of large hydrodynamic experiments driven by high explosives is a venerable diagnostic technique in use at many laboratories. Many of the largest hydrodynamic experiments study mockups of nuclear weapons, and are often called hydrotests for short. The dual-axis radiography for hydrodynamic testing (DARHT) facility uses two electron linear-induction accelerators (LIA) to produce the radiographic source spots for perpendicular views of a hydrotest. The first of these LIAs produces a single pulse, with a fixed {approx}60-ns pulsewidth. The second axis LIA produces as many as four pulses within 1.6-{micro}s, with variable pulsewidths and separation. There are a wide variety of hydrotest geometries, each with a unique radiographic requirement, so there is a need to adjust the radiographic dose for the best images. This can be accomplished on the second axis by simply adjusting the pulsewidths, but is more problematic on the first axis. Changing the beam energy or introducing radiation attenuation also changes the spectrum, which is undesirable. Moreover, using radiation attenuation introduces significant blur, increasing the effective spot size. The dose can also be adjusted by changing the beam kinetic energy. This is a very sensitive method, because the dose scales as the {approx}2.8 power of the energy, but it would require retuning the accelerator. This leaves manipulating the beam current as the best means for adjusting the dose, and one way to do this is to change the size of the cathode. This method has been proposed, and is being tested. This article describes simulations undertaken to develop scaling laws for use as design tools in changing the Axis-1 beam current by changing the cathode size.

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

2012-06-14T23:59:59.000Z

152

Fluctuating hydrodynamics and correlation lengths in a driven granular fluid  

E-Print Network (OSTI)

Static and dynamical structure factors for shear and longitudinal modes of the velocity and density fields are computed for a granular system fluidized by a stochastic bath with friction. Analytical expressions are obtained through fluctuating hydrodynamics and are successfully compared with numerical simulations up to a volume fraction $\\sim 50%$. Hydrodynamic noise is the sum of external noise due to the bath and internal one due to collisions. Only the latter is assumed to satisfy the fluctuation-dissipation relation with the average granular temperature. Static velocity structure factors $S_\\perp(k)$ and $S_\\parallel(k)$ display a general non-constant behavior with two plateaux at large and small $k$, representing the granular temperature $T_g$ and the bath temperature $T_b>T_g$ respectively. From this behavior, two different velocity correlation lengths are measured, both increasing as the packing fraction is raised. This growth of spatial order is in agreement with the behaviour of dynamical structure factors, the decay of which becomes slower and slower at increasing density.

Giacomo Gradenigo; Alessandro Sarracino; Dario Villamaina; Andrea Puglisi

2011-07-07T23:59:59.000Z

153

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

154

Numerical simulation of the hydrodynamical combustion to strange quark matter  

Science Conference Proceedings (OSTI)

We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable u,d,s quark matter. Our method solves hydrodynamical flow equations in one dimension with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change from heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature-dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below {approx_equal}2 times saturation density). In a two-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.

Niebergal, Brian; Ouyed, Rachid [Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 (Canada); Jaikumar, Prashanth [Department of Physics and Astronomy, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, California 90840 (United States); Institute of Mathematical Sciences, C.I.T. Campus, Chennai, TN 600113 (India)

2010-12-15T23:59:59.000Z

155

Radiation Hydrodynamics Test Problems with Linear Velocity Profiles  

Science Conference Proceedings (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

156

Method of simulating spherical voids for use as a radiographic standard  

DOE Patents (OSTI)

A method of simulating small spherical voids in metal is provided. The method entails drilling or etching a hemispherical depression of the desired diameter in each of two sections of metal, the sections being flat plates or different diameter cylinders. A carbon bead is placed in one of the hemispherical voids and is used as a guide to align the second hemispherical void with that in the other plate. The plates are then bonded together with epoxy, tape or similar material and the two aligned hemispheres form a sphere within the material; thus a void of a known size has been created. This type of void can be used to simulate a pore in the development of radiographic techniques of actual voids (porosity) in welds and serve as a radiographic standard.

Foster, Billy E. (Oak Ridge, TN)

1977-01-01T23:59:59.000Z

157

Nondestructive Evaluation: Recommended Practices for Maintaining Radiation Safety of Radiographic Operations at a Nuclear Plant  

Science Conference Proceedings (OSTI)

Radiation safety programs for radiographic operations at nuclear power plants are more complex than for those operations at other types of industrial and commercial facilities. This level of complexity arises because of the numerous challenges to maintenance of excellence in radiation safety at nuclear power facilities where sources of radiation may be found at various locations in the facility and multiple safety functions must be considered at all times. The facilities themselves are also large with mu...

2010-12-23T23:59:59.000Z

158

The space-time CESE method for solving special relativistic hydrodynamic equations  

Science Conference Proceedings (OSTI)

The special relativistic hydrodynamic equations are more complicated than the classical ones due to the nonlinear and implicit relations that exist between conservative and primitive variables. In this article, a space-time conservation element and solution ... Keywords: Conservation laws, Discontinuous solutions, Hyperbolic systems, Space-time CESE method, Special relativistic hydrodynamics

Shamsul Qamar; Muhammad Yousaf

2012-05-01T23:59:59.000Z

159

Using hydrodynamic modeling for estimating flooding and water depths in grand bay, alabama  

Science Conference Proceedings (OSTI)

This paper presents a methodology for using hydrodynamic modeling to estimate inundation areas and water depths during a hurricane event. The Environmental Fluid Dynamic Code (EFDC) is used in this research. EFDC is one of the most commonly applied models ... Keywords: EFDC, flooding, grand bay, grid generation, hydrodynamics, inundation, modeling

Vladimir J. Alarcon; William H. McAnally

2012-06-01T23:59:59.000Z

160

A consistent approach for the coupling of radiation and hydrodynamics at low Mach number  

Science Conference Proceedings (OSTI)

We present a consistent numerical model for coupling radiation to hydrodynamics at low Mach number. The hydrodynamical model is based on a low-Mach asymptotic in the compressible flow that removes acoustic wave propagation while retaining the compressibility ... Keywords: Diffusion flame, Low-Mach number flows, M1 model, Natural convection, Radiation hydrodymanics

Bruno Dubroca; Mohammed Seaïd; Ioan Teleaga

2007-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Lagrangian shock hydrodynamics on tetrahedral meshes: A stable and accurate variational multiscale approach  

Science Conference Proceedings (OSTI)

In the past, a number of attempts have failed to robustly compute highly transient shock hydrodynamics flows on tetrahedral meshes. To a certain degree, this is not a surprise, as prior attempts emphasized enhancing the structure of shock-capturing operators ... Keywords: Lagrangian shock hydrodynamics, Nodal finite element method, Stabilized methods, Tetrahedral grids, Updated Lagrangian formulation, Variational multiscale analysis

G. Scovazzi

2012-10-01T23:59:59.000Z

162

A matrix free implicit scheme for solution of resistive magneto-hydrodynamics equations on unstructured grids  

Science Conference Proceedings (OSTI)

The resistive magneto-hydrodynamics (MHD) governing equations represent eight conservation equations for the evolution of density, momentum, energy and induced magnetic fields in an electrically conducting fluid, typically a plasma. A matrix free implicit ... Keywords: Finite volume methods, Implicit schemes, Lower-Upper Symmetric Gauss Seidel, Magneto-hydrodynamics, Matrix-free, Unstructured grids

H. Sitaraman, L. L. Raja

2013-10-01T23:59:59.000Z

163

Stability analysis of a predictor/multi-corrector method for staggered-grid Lagrangian shock hydrodynamics  

Science Conference Proceedings (OSTI)

This article presents the complete von Neumann stability analysis of a predictor/multi-corrector scheme derived from an implicit mid-point time integrator often used in shock hydrodynamics computations in combination with staggered spatial discretizations. ... Keywords: Lagrangian shock hydrodynamics, Mid-point time integrator, Predictor/multi-corrector algorithm, Staggered formulation, von Neumann stability analysis

E. Love; W. J. Rider; G. Scovazzi

2009-11-01T23:59:59.000Z

164

Smoothed particle hydrodynamics non-Newtonian model for ice-sheet and ice-shelf dynamics  

Science Conference Proceedings (OSTI)

We propose a new three-dimensional smoothed particle hydrodynamics (SPH) non-Newtonian model to study coupled ice-sheet and ice-shelf dynamics. Most existing ice-sheet numerical models use grid-based Eulerian discretizations, and are usually restricted ... Keywords: Grounding line, Ice sheet, Non-Newtonian fluid, Smoothed particle hydrodynamics

W. Pan, A. M. Tartakovsky, J. J. Monaghan

2013-06-01T23:59:59.000Z

165

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

Science Conference Proceedings (OSTI)

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

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

2011-03-01T23:59:59.000Z

166

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

Science Conference Proceedings (OSTI)

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

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

2013-11-01T23:59:59.000Z

167

Finite volume local evolution Galerkin method for two-dimensional relativistic hydrodynamics  

Science Conference Proceedings (OSTI)

The paper proposes a second-order accurate finite volume local evolution Galerkin (FVLEG) method for two-dimensional special relativistic hydrodynamical (RHD) equations. Instead of using the dimensional splitting method or solving one-dimensional local ... Keywords: Evolution operator, Finite volume local evolution Galerkin method, Genuinely multi-dimensional method, Relativistic hydrodynamics

Kailiang Wu, Huazhong Tang

2014-01-01T23:59:59.000Z

168

Low Mach Number Fluctuating Hydrodynamics of Diffusively Mixing Fluids  

E-Print Network (OSTI)

We formulate low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different density and transport coefficients. These equations eliminate the fast isentropic fluctuations in pressure associated with the propagation of sound waves by replacing the equation of state with a local thermodynamic constraint. We demonstrate that the low Mach number model preserves the spatio-temporal spectrum of the slower diffusive fluctuations. We develop a strictly conservative finite-volume spatial discretization of the low Mach number fluctuating equations in both two and three dimensions. We construct several explicit Runge-Kutta temporal integrators that strictly maintain the equation of state constraint. The resulting spatio-temporal discretization is second-order accurate deterministically and maintains fluctuation-dissipation balance in the linearized stochastic equations. We apply our algorithms to model the development of giant concentration fl...

Donev, A; Sun, Y; Fai, T; Garcia, A L; Bell, J B

2012-01-01T23:59:59.000Z

169

Hydro-dynamical models for the chaotic dripping faucet  

E-Print Network (OSTI)

We give a hydrodynamical explanation for the chaotic behaviour of a dripping faucet using the results of the stability analysis of a static pendant drop and a proper orthogonal decomposition (POD) of the complete dynamics. We find that the only relevant modes are the two classical normal forms associated with a Saddle-Node-Andronov bifurcation and a Shilnikov homoclinic bifurcation. This allows us to construct a hierarchy of reduced order models including maps and ordinary differential equations which are able to qualitatively explain prior experiments and numerical simulations of the governing partial differential equations and provide an explanation for the complexity in dripping. We also provide a new mechanical analogue for the dripping faucet and a simple rationale for the transition from dripping to jetting modes in the flow from a faucet.

P. Coullet; L. Mahadevan; C. S. Riera

2004-08-20T23:59:59.000Z

170

Symposium on hydrodynamic diffusion of suspended particles. Final report  

SciTech Connect

The symposium brought together researchers from academic, government, and private laboratories interested in the interactions of particles in fluids and in granular media. There were 68 participants, including 24 students, currently residing In 12 countries. The participants represented a wide variety of fields, including applied mathematics, chemical engineering, computer science, fluid dynamics, materials science, mechanical engineering, physics, and theoretical and applied mechanics. There were 33 talks and 16 posters presented. The focus of the symposium was on multiparticle hydrodynamic interactions which lead to fluctuating motion of the particles and resulting particle migration and dispersion or diffusion. Implications of these phenomena were described for sedimentation, fluidization, suspension flows, granular flows, and fiber suspensions. Computer simulation techniques as well as experimental techniques were described.

1996-05-01T23:59:59.000Z

171

Physical viscosity in smoothed particle hydrodynamics simulations of galaxy clusters  

E-Print Network (OSTI)

Most hydrodynamical simulations of galaxy cluster formation carried out to date have tried to model the cosmic gas as an ideal, inviscid fluid, where only a small amount of (unwanted) numerical viscosity is present, arising from practical limitations of the numerical method employed, and with a strength that depends on numerical resolution. However, the physical viscosity of the gas in hot galaxy clusters may in fact not be negligible, suggesting that a self-consistent treatment that accounts for the internal gas friction would be more appropriate. To allow such simulations using the smoothed particle hydrodynamics (SPH) method, we derive a novel SPH formulation of the Navier-Stokes and general heat transfer equations and implement them in the GADGET-2 code. We include both shear and bulk viscosity stress tensors, as well as saturation criteria that limit viscous stress transport where appropriate. Adopting Braginskii's parameterization for the shear viscosity of hot gaseous plasmas, we then study the influence of viscosity on the interplay between AGN-inflated bubbles and the surrounding intracluster medium (ICM). We find that certain bubble properties like morphology, maximum clustercentric radius reached, or survival time depend quite sensitively on the assumed level of viscosity. Interestingly, the sound waves launched into the ICM by the bubble injection are damped by physical viscosity, establishing a non-local heating process. Finally, we carry out cosmological simulations of galaxy cluster formation with a viscous intracluster medium. Viscosity modifies the dynamics of mergers and the motion of substructures through the cluster atmosphere. Substructures are generally more efficiently stripped of their gas, leading to prominent long gaseous tails behind infalling massive halos. (Abridged)

Debora Sijacki; Volker Springel

2006-05-11T23:59:59.000Z

172

LANL | Physics | Nuclear Weapons and Global Security Data Analysis  

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

Nuclear Weapons and Global Security Data Analysis Nuclear Weapons and Global Security Data Analysis Physics Division applies advanced imaging techniques to many applications, from brain imaging to neutron imaging in inertial fusion to threat detection from airborne cameras. A particular strength is the quantitative analysis of penetrating radiography using techniques such as the Bayesian Inference Engine (BIE). An example from the Nuclear Event Analysis Team shows a test object (Figure 1) that is subsequently radiographed using the Dual-Axis Radiography Hydrodynamic Test (DARHT) facility. Figures 2 and 3 show the radiograph and the inferred density of the object using the BIE, which can be compared to the known object to determine accurate error estimation. Test object Figure 1. The test object consists of a 1 cm-radius cavity void surrounded by a 4.5 cm radius surrogate fissile material of tungsten, tantalum, or depleted uranium. This sphere is surrounded by a 6.5 cm-radius copper sphere. At is thickest point, the tantalum test object has an areal density of 180 g/cm2, equivalent to 9" of steel.

173

Equilibrium and hydrodynamic studies of water extraction from fermentation broth  

E-Print Network (OSTI)

Previous studies using tertiary amines to extract water from reagent-grade carboxylate salts (calcium acetate, propionate, and butyrate) have shown selectivity for water and not for the carboxylate salts. These results allow the design of an extraction system to concentrate fermentation broth from a mixed culture of acid-forming microorganisms. To design the extraction system, equilibrium data from amine and actual fermentation broth systems were obtained. These data are similar to the data found previously for reagent-grade pure components. The data were manipulated to obtain graphs for the Ponchon-Savarit procedure used to design multi-stage extractors. Different cases were studied in which the feed was varied. A 3.8 wt% solution could be concentrated to 17.5 wt% using five countercurrent stripping stages; however, the recovery of carboxylate salts was poor (68 wt%) with this design. To overcome this, a reflux stream and an enriching section were employed. The Janecke procedure was followed to determine the member of equilibrium stages for the skipping and the enriching sections and their operating conditions. For this case, eight stages (two enriching and six stripping) were required to concentrate the carboxylate salts from an initial concentration of 3.8 up to 20 wt%. The salt recovery was 91%, the amine:water ratio was 2.5:1 and the reflux:feed ratio was 2.4:1. This design gives good results and will be implemented in a pilot plant. To study the separation of the organic and aqueous phases, a bench-scale mixer/settler extraction tank was designed and constructed. This apparatus had three sections: a mixing section to blend the two phases, a coalescence section in which the amine and water phases coalesce, and a decanting section in which the liquids completely separate. Several experiments were made to determine the hydrodynamic properties of the mixer/settler. The experiments showed that the apparatus is suitable to perform liquid-liquid extraction. Independent experiments were made using a coalesced apparatus to better analyze what occurs in the coalescing section. A model to describe the hydrodynamic of the liquid mixture in the coalesced apparatus was applied to the system giving good agreement with the experimental data.

Adorno-Gomez, Wilberto

1999-01-01T23:59:59.000Z

174

Development of an LED reference light source for calibration of radiographic imaging detectors  

E-Print Network (OSTI)

A stable reference light source based on an LED (Light Emission Diode) is presented for stabilizing the conversion gain of the opto-electronic system of a gamma- and fast-neutron radiographic and tomographic imaging device. A constant fraction of the LED light is transported to the image plane of the camera and provides a stable reference exposure. This is used to normalize the images during off-line image processing. We have investigated parameters influencing the stability of LEDs and developed procedures and criteria to prepare and select LEDs suitable for delivering stable light outputs for several 100 h of operation.

Weierganz, M; Bromberger, B; Dangendorf, V; Feldman, G; Goldberg, M B; Lindemann, M; Mor, I; Tittelmeier, K; Vartsky, D

2010-01-01T23:59:59.000Z

175

Development of an LED reference light source for calibration of radiographic imaging detectors  

E-Print Network (OSTI)

A stable reference light source based on an LED (Light Emission Diode) is presented for stabilizing the conversion gain of the opto-electronic system of a gamma- and fast-neutron radiographic and tomographic imaging device. A constant fraction of the LED light is transported to the image plane of the camera and provides a stable reference exposure. This is used to normalize the images during off-line image processing. We have investigated parameters influencing the stability of LEDs and developed procedures and criteria to prepare and select LEDs suitable for delivering stable light outputs for several 100 h of operation.

M. Weierganz; D. Bar; B. Bromberger; V. Dangendorf; G. Feldman; M. B. Goldberg; M. Lindemann; I. Mor; K. Tittelmeier; D. Vartsky

2010-02-08T23:59:59.000Z

176

An image-based technique to assess the perceptual quality of clinical chest radiographs  

SciTech Connect

Purpose: Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system modulation transfer function, noise power spectrum, detective quantum efficiency, and the exposure technique. While these elements form the basic underlying components of image quality, when assessing a clinical image, radiologists seldom refer to these factors, but rather examine several specific regions of the displayed patient images, further impacted by a particular image processing method applied, to see whether the image is suitable for diagnosis. In this paper, the authors developed a novel strategy to simulate radiologists' perceptual evaluation process on actual clinical chest images. Methods: Ten regional based perceptual attributes of chest radiographs were determined through an observer study. Those included lung grey level, lung detail, lung noise, rib-lung contrast, rib sharpness, mediastinum detail, mediastinum noise, mediastinum alignment, subdiaphragm-lung contrast, and subdiaphragm area. Each attribute was characterized in terms of a physical quantity measured from the image algorithmically using an automated process. A pilot observer study was performed on 333 digital chest radiographs, which included 179 PA images with 10:1 ratio grids (set 1) and 154 AP images without grids (set 2), to ascertain the correlation between image perceptual attributes and physical quantitative measurements. To determine the acceptable range of each perceptual attribute, a preliminary quality consistency range was defined based on the preferred 80% of images in set 1. Mean value difference ({mu}{sub 1}-{mu}{sub 2}) and variance ratio ({sigma}{sub 1}{sup 2}/{sigma}{sub 2}{sup 2}) were investigated to further quantify the differences between the selected two image sets. Results: The pilot observer study demonstrated that our regional based physical quantity metrics of chest radiographs correlated very well with their corresponding perceptual attributes. The distribution comparisons, mean value difference estimations, and variance ratio estimations of each physical quantity between sets of images from two different techniques matched our expectation that the image quality of set 1 should be better than that of set 2. Conclusions: The measured physical quantities provide a robust reflection of perceptual image quality in clinical images. The methodology can be readily applied for automated evaluation of perceptual image quality in clinical chest radiographs.

Lin Yuan; Luo Hui; Dobbins, James T. III; Page McAdams, H.; Wang, Xiaohui; Sehnert, William J.; Barski, Lori; Foos, David H.; Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, 2424 Erwin Road, Suite 302, Durham, North Carolina 27705 (United States); Carestream Health, Inc., 1049 Ridge Road West, Rochester, New York 14615 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, 2424 Erwin Road, Suite 302, Durham, North Carolina 27705 (United States); Carestream Health, Inc., 1049 Ridge Road West, Rochester, New York 14615 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, 2424 Erwin Road, Suite 302, Durham, North Carolina 27705 (United States)

2012-11-15T23:59:59.000Z

177

Low Mach Number Fluctuating Hydrodynamics of Diffusively Mixing Fluids  

E-Print Network (OSTI)

We formulate low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different density and transport coefficients. These equations eliminate the fast isentropic fluctuations in pressure associated with the propagation of sound waves by replacing the equation of state with a local thermodynamic constraint. We demonstrate that the low Mach number model preserves the spatio-temporal spectrum of the slower diffusive fluctuations. We develop a strictly conservative finite-volume spatial discretization of the low Mach number fluctuating equations in both two and three dimensions. We construct several explicit Runge-Kutta temporal integrators that strictly maintain the equation of state constraint. The resulting spatio-temporal discretization is second-order accurate deterministically and maintains fluctuation-dissipation balance in the linearized stochastic equations. We apply our algorithms to model the development of giant concentration fluctuations in the presence of concentration gradients, and investigate the validity of common simplifications neglecting the spatial non-homogeneity of density and transport properties. We perform simulations of diffusive mixing of two fluids of different densities in two dimensions and compare the results of low Mach number continuum simulations to hard-disk molecular dynamics simulations. Excellent agreement is observed between the particle and continuum simulations of giant fluctuations during time-dependent diffusive mixing.

A. Donev; A. J. Nonaka; Y. Sun; T. G. Fai; A. L. Garcia; J. B. Bell

2012-12-11T23:59:59.000Z

178

IUTAM symposium on hydrodynamic diffusion of suspended particles  

Science Conference Proceedings (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

179

Hydrodynamical simulations of cluster formation with central AGN heating  

E-Print Network (OSTI)

We analyse a hydrodynamical simulation model for the recurrent heating of the central intracluster medium (ICM) by active galactic nuclei (AGN). Besides the self-gravity of the dark matter and gas components, our approach includes the radiative cooling and photoheating of the gas, as well as a subresolution multiphase model for star formation and supernova feedback. Additionally, we incorporate a periodic heating mechanism in the form of hot, buoyant bubbles, injected into the intragalactic medium (IGM) during the active phases of the accreting central AGN. We use simulations of isolated cluster halos of different masses to study the bubble dynamics and the heat transport into the IGM. We also apply our model to self-consistent cosmological simulations of the formation of galaxy clusters with a range of masses. Our numerical schemes explore a variety of different assumptions for the spatial configuration of AGN-driven bubbles, for their duty cycles and for the energy injection mechanism, in order to obtain better constraints on the underlying physical picture. We argue that AGN heating can substantially affect the properties of both the stellar and gaseous components of clusters of galaxies. Most importantly, it alters the properties of the central dominant (cD) galaxy by reducing the mass deposition rate of freshly cooled gas out of the ICM, thereby offering an energetically plausible solution to the cooling flow problem. At the same time, this leads to reduced or eliminated star formation in the central cD galaxy, giving it red stellar colours as observed.

Debora Sijacki; Volker Springel

2005-09-16T23:59:59.000Z

180

Thermal and hydrodynamic effects in the ordering of lamellar fluids  

E-Print Network (OSTI)

Phase separation in a complex fluid with lamellar order has been studied in the case of cold thermal fronts propagating diffusively from external walls. The velocity hydrodynamic modes are taken into account by coupling the convection-diffusion equation for the order parameter to a generalised Navier-Stokes equation. The dynamical equations are simulated by implementing a hybrid method based on a lattice Boltzmann algorithm coupled to finite difference schemes. Simulations show that the ordering process occurs with morphologies depending on the speed of the thermal fronts or, equivalently, on the value of the thermal conductivity {\\xi}. At large value of {\\xi}, as in instantaneous quenching, the system is frozen in entangled configurations at high viscosity while consists of grains with well ordered lamellae at low viscosity. By decreasing the value of {\\xi}, a regime with very ordered lamellae parallel to the thermal fronts is found. At very low values of {\\xi} the preferred orientation is perpendicular to the walls in d = 2, while perpendicular order is lost moving far from the walls in d = 3.

G. Gonnella; A. Lamura; A. Tiribocchi

2011-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. III. MULTIGROUP RADIATION HYDRODYNAMICS  

SciTech Connect

We present a formulation for multigroup radiation hydrodynamics that is correct to order O(v/c) using the comoving-frame approach and the flux-limited diffusion approximation. We describe a numerical algorithm for solving the system, implemented in the compressible astrophysics code, CASTRO. CASTRO uses a Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of logically rectangular variable-sized grids with simultaneous refinement in both space and time. In our multigroup radiation solver, the system is split into three parts: one part that couples the radiation and fluid in a hyperbolic subsystem, another part that advects the radiation in frequency space, and a parabolic part that evolves radiation diffusion and source-sink terms. The hyperbolic subsystem and the frequency space advection are solved explicitly with high-order Godunov schemes, whereas the parabolic part is solved implicitly with a first-order backward Euler method. Our multigroup radiation solver works for both neutrino and photon radiation.

Zhang, W.; Almgren, A.; Bell, J. [Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Howell, L. [Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Burrows, A.; Dolence, J. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2013-01-15T23:59:59.000Z

182

Experimental characterization of slurry bubble-column reactor hydrodynamics  

DOE Green Energy (OSTI)

Sandia`s program to develop, implement, and apply diagnostics for hydrodynamic characterization of slurry bubble column reactors (SBCRs) at industrially relevant conditions is discussed. Gas liquid flow experiments are performed on an industrial scale. Gamma densitometry tomography (GDT) is applied to measure radial variations in gas holdup at one axial location. Differential pressure (DP) measurements are used to calculate volume averaged gas holdups along the axis of the vessel. The holdups obtained from DP show negligible axial variation for water but significant variations for oil, suggesting that the air water flow is fully developed (minimal flow variations in the axial direction) but that the air oil flow is still developing at the GDT measurement location. The GDT and DP gas holdup results are in good agreement for the air water flow but not for the air oil flow. Strong flow variations in the axial direction may be impacting the accuracy of one or both of these techniques. DP measurements are also acquired at high sampling frequencies (250 Hz) and are interpreted using statistical analyses to determine the physical mechanism producing each frequency component in the flow. This approach did not yield the information needed to determine the flow regime in these experiments. As a first step toward three phase material distribution measurements, electrical impedance tomography (EIT) and GDT are applied to a liquid solid flow to measure solids holdup. Good agreement is observed between both techniques and known values.

Shollenberger, K.A.; Torczynski, J.R.; Jackson, N.B.; O`Hern, T.J.

1997-09-01T23:59:59.000Z

183

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

184

CO2-Water-Rock Interactions and the Integrity of Hydrodynamic...  

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

InteraCtIOns and the IntegrIty Of hydrOdynamIC seals Background Developing confidence in methods of sequestering carbon dioxide (CO 2 ) in geological formations requires an...

185

Physico-chemical hydrodynamics of droplets on textured surfaces with engineered micro/nanostructures  

E-Print Network (OSTI)

Understanding physico-chemical hydrodynamics of droplets on textured surfaces is of fundamental and practical significance for designing a diverse range of engineered surfaces such as low-reflective, self-cleaning or ...

Park, Kyoo Chul

2013-01-01T23:59:59.000Z

186

Theoretical Formulation of Collision Rate and Collision Efficiency of Hydrodynamically Interacting Cloud Droplets in Turbulent Atmosphere  

Science Conference Proceedings (OSTI)

A methodology for conducting direct numerical simulations (DNSs) of hydrodynamically interacting droplets in the context of cloud microphysics has been developed and used to validate a new kinematic formulation capable of describing the collision ...

Lian-Ping Wang; Orlando Ayala; Scott E. Kasprzak; Wojciech W. Grabowski

2005-07-01T23:59:59.000Z

187

A Coupled Hydrodynamic–Bottom Boundary Layer Model of Ekman Flow on Stratified Continental Shelves  

Science Conference Proceedings (OSTI)

This paper describes a hydrodynamic model with turbulent energy closure that uses a simplified wave-current interaction model of the bottom boundary layer to compute bed drag coefficients. The coupled model is used to investigate the interaction ...

Timothy R. Keen; Scott M. Glenn

1994-08-01T23:59:59.000Z

188

Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines  

Science Conference Proceedings (OSTI)

This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

2011-10-01T23:59:59.000Z

189

Using high-intensity laser-generated energetic protons to radiograph directly driven implosions  

Science Conference Proceedings (OSTI)

The recent development of petawatt-class lasers with kilojoule-picosecond pulses, such as OMEGA EP [L. Waxer et al., Opt. Photonics News 16, 30 (2005)], provides a new diagnostic capability to study inertial-confinement-fusion (ICF) and high-energy-density (HED) plasmas. Specifically, petawatt OMEGA EP pulses have been used to backlight OMEGA implosions with energetic proton beams generated through the target normal sheath acceleration (TNSA) mechanism. This allows time-resolved studies of the mass distribution and electromagnetic field structures in ICF and HED plasmas. This principle has been previously demonstrated using Vulcan to backlight six-beam implosions [A. J. Mackinnon et al., Phys. Rev. Lett. 97, 045001 (2006)]. The TNSA proton backlighter offers better spatial and temporal resolution but poorer spatial uniformity and energy resolution than previous D{sup 3}He fusion-based techniques [C. Li et al., Rev. Sci. Instrum. 77, 10E725 (2006)]. A target and the experimental design technique to mitigate potential problems in using TNSA backlighting to study full-energy implosions is discussed. The first proton radiographs of 60-beam spherical OMEGA implosions using the techniques discussed in this paper are presented. Sample radiographs and suggestions for troubleshooting failed radiography shots using TNSA backlighting are given, and future applications of this technique at OMEGA and the NIF are discussed.

Zylstra, A. B.; Li, C. K.; Rinderknecht, H. G.; Seguin, F. H.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Stoeckl, C.; Meyerhofer, D. D.; Nilson, P.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Le Pape, S.; Mackinnon, A.; Patel, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2012-01-15T23:59:59.000Z

190

In-flight radiographic study of two nonaxisymmetric, explosively formed penetrators  

Science Conference Proceedings (OSTI)

We present in-flight radiographic images of two explosively formed penetrators (EFPs) of tantalum. The data were obtained with Ecto, a flash x-ray source that delivers a single, 50-ns pulse of radiation with an effective mean energy of 1.4)pulse))minus) 0.1 MeV. The enrgy and flux of the beam are sufficient to penetrate the EFPs and reveal their internal structure. The subjects of this study are two warheads of an identical nonaxisymmetric design. One warhead was fired in each of two separate experiments. The warheads were oriented perpendicular to one another to provide separate orthogonal views of their EFPs. The radiographs were then digitized and subjected to several numerical analyses, which include estimates of the masses of the EFPs, their center-of-mass coordinates, and plots of the attenuation lengths (or material thicknesses) at various positions. Optical photographs were also taken of the front and profile of one EFP. The optical data aid in interpretating the radioagraphy by allowing identification of the visible external features. 3 refs., 16 figs.

Schwalbe, L.A.; Mueller, K.H. Jr.; Christian, J.M.; DiBona, P.J.

1988-03-01T23:59:59.000Z

191

Runge-Kutta discontinuous Galerkin methods with WENO limiter for the special relativistic hydrodynamics  

Science Conference Proceedings (OSTI)

This paper develops the P^K-based Runge-Kutta discontinuous Galerkin (RKDG) methods with WENO limiter for the one- and two-dimensional special relativistic hydrodynamics, K=1,2,3, which is an extension of the work [J.X. Qiu, C.-W. Shu, Runge-Kutta discontinuous ... Keywords: Discontinuous Galerkin method, Relativistic hydrodynamics, Runge-Kutta time discretization, WENO limiter

Jian Zhao, Huazhong Tang

2013-06-01T23:59:59.000Z

192

Experimental techniques for hydrodynamic characterization of multiphase flows in slurry-phase bubble-column reactors  

DOE Green Energy (OSTI)

Slurry-phase bubble-column Fischer-Tropsch (FT) reactors are recognized as one of the more promising technologies for converting synthesis gas from coal into liquid fuel products (indirect liquefaction). However, hydrodynamic effects must be considered when attempting to scale these reactors to sizes of industrial interest. The objective of this program is to facilitate characterization of reactor hydrodynamics by developing and applying noninvasive tomographic diagnostics capable of measuring gas holdup spatial distribution in these reactors.

Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Shollenberger, K.A.; Mondy, L.A.; Jackson, N.B.

1994-09-01T23:59:59.000Z

193

Heat transfer and hydrodynamics analysis of a novel dimpled tube  

SciTech Connect

In the present investigation, heat transfer and hydrodynamics analysis of a new enhanced heat transfer tube with ellipsoidal dimples was carried out. The dimples are disposed to form a certain specified angle between the major axis of the ellipsoid and flow direction, and the direction of the major axis of each adjacent ellipsoidal dimple in the same cross-section is alternated. Experimental tests were carried out with heating water on the shell side with a constant flow rate, and cold air in the tube side with flow rates range from 1 to 55 m{sup 3}/h. The temperatures and pressures for the inlet and outlet of both sides were measured. The heat transfer and pressure drop of the new dimpled tube were investigated and compared with the results of a dimpled tube with spherical dimples and a conventional smooth tube. The computed results indicated that the Nusselt number for ellipsoidal dimpled tube and spherical dimpled tube are 38.6-175.1% and 34.1-158% higher than that for the smooth tube respectively. The friction factors of dimpled tube increase by 26.9-75% and 32.9-92% for ellipsoidal and spherical dimples compared with the smooth tube respectively. It was perceived that ellipsoidal dimple roughness accelerates transition to critical Reynolds numbers down to less than 1000. By integrated performance evaluation of (Nu{sub a}/Nu{sub s})/(f{sub a}/f{sub s}), a maximum of about 87% heat transfer enhancement with the same friction penalty could be achieved by optimize the dimpled tube design. (author)

Wang, Yu.; He, Ya-Ling; Lei, Yong-Gang; Zhang, Jie [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-11-15T23:59:59.000Z

194

Fully integrated transport approach to heavy ion reactions with an intermediate hydrodynamic stage  

E-Print Network (OSTI)

We present a coupled Boltzmann and hydrodynamics approach to relativistic heavy ion reactions. This hybrid approach is based on the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport approach with an intermediate hydrodynamical evolution for the hot and dense stage of the collision. Event-by-event fluctuations are directly taken into account via the non-equilibrium initial conditions generated by the initial collisions and string fragmentations in the microscopic UrQMD model. After a (3+1)-dimensional ideal hydrodynamic evolution, the hydrodynamical fields are mapped to hadrons via the Cooper-Frye equation and the subsequent hadronic cascade calculation within UrQMD proceeds to incorporate the important final state effects for a realistic freeze-out. This implementation allows to compare pure microscopic transport calculations with hydrodynamic calculations using exactly the same initial conditions and freeze-out procedure. The effects of the change in the underlying dynamics - ideal fluid dynamics vs. non-equilibrium transport theory - will be explored. The freeze-out and initial state parameter dependences are investigated for different observables. Furthermore, the time evolution of the baryon density and particle yields are discussed. We find that the final pion and proton multiplicities are lower in the hybrid model calculation due to the isentropic hydrodynamic expansion while the yields for strange particles are enhanced due to the local equilibrium in the hydrodynamic evolution. The results of the different calculations for the mean transverse mass excitation function, rapidity and transverse mass spectra for different particle species at three different beam energies are discussed in the context of the available data.

Hannah Petersen; Jan Steinheimer; Gerhard Burau; Marcus Bleicher; Horst Stöcker

2008-06-10T23:59:59.000Z

195

X-ray radiographic technique for measuring density uniformity of silica aerogel  

E-Print Network (OSTI)

This paper proposes a new X-ray radiographic technique for measuring density uniformity of silica aerogels used as radiator in proximity-focusing ring-imaging Cherenkov detectors. To obtain high performance in a large-area detector, a key characteristic of radiator is the density (i.e. refractive index) uniformity of an individual aerogel monolith. At a refractive index of n = 1.05, our requirement for the refractive index uniformity in the transverse plane direction of an aerogel tile is |\\delta (n - 1)/(n - 1)| aerogels from a trial production and that of Panasonic products (SP-50) as a reference, and to confirm they have sufficient density uniformity within \\pm 1% along the transverse plane direction. The measurement results show that the proposed technique can quantitatively estimate the density uniformity of aerogels.

Makoto Tabata; Yoshikiyo Hatakeyama; Ichiro Adachi; Takeshi Morita; Keiko Nishikawa

2012-12-14T23:59:59.000Z

196

Hydrodynamic sweepout thresholds in BWR Mark III reactor cavity interactions  

DOE Green Energy (OSTI)

Simulant-material experiments and related analysis are described which investigated hydrodynamics aspects of ex-vessel interactions following postulated core meltdown with subsequent meltthrough of the vessel lower head and ejection of molten corium from the vessel into the containment region beneath the vessel. Objectives were to examine the possible sweepout of water and corium from the cavity by the steam/H/sub 2/ flow. The dispersal pathways in this containment design include a single manway and four CRD penetrations in the cylindrical pedestal wall connecting to the drywell with a combined cross-sectional area of approx. 10 m/sup 2/. These openings range from 3.4 to 6.3 m in elevation off the concrete floor of the cavity. The experiments were performed using a 1:34 scale mock-up of the RPV/pedestal region. The first tests were quasi-steady tests. Tests were also performed using molten Wood's metal (WM). Some tests were performed with water on the cavity floor, and one test was performed using steel shot. The test results indicated that threshold gas flowrates existed beyond which dispersal of water and/or corium from the cavity can be expected. The predominant dispersal flow regime observed in the experiments involved fluidization of the water or molten WM by the gas flowrate through the system and sweepout of the fluidized liquid droplets as the gas exited the cavity through the openings in the wall. The superficial gas velocity at the onset of water sweepout ranged from 0.87 to 1.04 m/s in the tests which agrees very closely to the calculated fluidization threshold of 0.96 m/s. Application of the fluidization model for prediction of sweepout for the full-size system suggests that sweepout of water and corium can occur if the breach size in the RPV lower head exceeds approx. 10 and 17 cm dia, respectively, for steam blowdown at a vessel initial pressure of 1000 psi.

Spencer, B.W.; Baronowsky, S.P.; Kilsdonk, D.J.

1984-04-01T23:59:59.000Z

197

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

SciTech Connect

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

198

Efficient calculation of dewatered and entrapped areas using hydrodynamic modeling and GIS  

Science Conference Proceedings (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 ... Keywords: Columbia River, Dewatering, Entrapment, Fish, GIS, Hydrodynamic model, Power peaking

Marshall C. Richmond; William A. Perkins

2009-12-01T23:59:59.000Z

199

A second order self-consistent IMEX method for radiation hydrodynamics  

Science Conference Proceedings (OSTI)

We present a second order self-consistent implicit/explicit (methods that use the combination of implicit and explicit discretizations are often referred to as IMEX (implicit/explicit) methods [2,1,3]) time integration technique for solving radiation ... Keywords: Radiation hydrodynamics, Self-consistent IMEX method

Samet Y. Kadioglu; Dana A. Knoll; Robert B. Lowrie; Rick M. Rauenzahn

2010-11-01T23:59:59.000Z

200

Elliptic flow from event-by-event hydrodynamics with fluctuating initial state  

E-Print Network (OSTI)

We develop an event-by-event ideal hydrodynamical framework where initial state density fluctuations are present and where we use a similar flow-analysis method as in the experiments to make a one-to-one $v_2$ comparison with the measured data. Our studies also show that the participant plane is quite a good approximation for the event plane.

Holopainen, Hannu; Eskola, Kari J

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Recent Hydrodynamics Improvements to the RELAP5-3D Code  

SciTech Connect

The hydrodynamics section of the RELAP5-3D computer program has been recently improved. Changes were made as follows: (1) improved turbine model, (2) spray model for the pressurizer model, (3) feedwater heater model, (4) radiological transport model, (5) improved pump model, and (6) compressor model.

Richard A. Riemke; Cliff B. Davis; Richard.R. Schultz

2009-07-01T23:59:59.000Z

202

Hydrodynamic simulation of air bubble implosion using a level set approach  

Science Conference Proceedings (OSTI)

The hydrodynamics of the implosion and rebound of a small (10 µm diameter) air bubble in water was studied using a three-dimensional direct numerical simulation (DNS). To study this problem, we developed a novel stabilized finite element method ... Keywords: bubble implosion, finite element, level set, two phase-flow

Sunitha Nagrath; Kenneth Jansen; Richard T. Lahey, Jr.; Iskander Akhatov

2006-06-01T23:59:59.000Z

203

Effect of Second-Order Hydrodynamics on Floating Offshore Wind Turbines: Preprint  

DOE Green Energy (OSTI)

Offshore winds are generally stronger and more consistent than winds on land, making the offshore environment attractive for wind energy development. A large part of the offshore wind resource is however located in deep water, where floating turbines are the only economical way of harvesting the energy. The design of offshore floating wind turbines relies on the use of modeling tools that can simulate the entire coupled system behavior. At present, most of these tools include only first-order hydrodynamic theory. However, observations of supposed second-order hydrodynamic responses in wave-tank tests performed by the DeepCwind consortium suggest that second-order effects might be critical. In this paper, the methodology used by the oil and gas industry has been modified to apply to the analysis of floating wind turbines, and is used to assess the effect of second-order hydrodynamics on floating offshore wind turbines. The method relies on combined use of the frequency-domain tool WAMIT and the time-domain tool FAST. The proposed assessment method has been applied to two different floating wind concepts, a spar and a tension-leg-platform (TLP), both supporting the NREL 5-MW baseline wind turbine. Results showing the hydrodynamic forces and motion response for these systems are presented and analysed, and compared to aerodynamic effects.

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

2013-07-01T23:59:59.000Z

204

Investigation of the hydrodynamic properties of a new MRI-resistant programmable hydrocephalus shunt  

E-Print Network (OSTI)

://www.cerebrospinalfluidresearch.com/content/5/1/8 The hydrodynamic resistance increases with the pressure performance level. The resistance at 8.21 – 14.2 mmHg/ ml/min matches and exceeds the normal CSF outflow resistance when the shunt is set at the highest pressure lev- els (150 to 200 mmH2O...

Allin, David M; Czosnyka, Marek; Richards, Hugh K; Pickard, John D; Czosnyka, Zofia

2008-04-21T23:59:59.000Z

205

High velocity impact of metal sphere on thin metallic plates: a comparative smooth particle hydrodynamics study  

Science Conference Proceedings (OSTI)

Four different shock-capturing schemes used in smooth particle hydrodynamics are compared as applied to moderately high-velocity impacts (at 3 km/s) and hypervelocity impacts (at ?6 km/s) of metallic projectiles on thin metal plates. The target ... Keywords: Riemann problem, artificial viscosity, hydrocode, hypervelocity impact

Vishal Mehra; Shashank Chaturvedi

2006-02-01T23:59:59.000Z

206

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

SciTech Connect

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

207

Hydrodynamic models for slurry bubble column reactors. Fifth technical progress report  

DOE Green Energy (OSTI)

The objective of this work is to convert our `learning gas-solid-liquid` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid, and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values.

Gidaspow, D.

1995-10-01T23:59:59.000Z

208

Initial condition for hydrodynamics, partonic free streaming, and the uniform description of soft observables at RHIC  

E-Print Network (OSTI)

We investigate the role of the initial condition used for the hydrodynamic evolution of the system formed in ultra-relativistic heavy-ion collisions and find that an appropriate choice motivated by the models of early-stage dynamics, specifically a simple two-dimensional Gaussian profile, leads to a uniform description of soft observables measured in the Relativistic Heavy-Ion Collider (RHIC). In particular, the transverse-momentum spectra, the elliptic-flow, and the Hanbury-Brown--Twiss correlation radii, including the ratio R_out/R_side as well as the dependence of the radii on the azimuthal angle (azHBT), are properly described. We use the perfect-fluid hydrodynamics with a realistic equation of state based on lattice calculations and the hadronic gas at high and low temperatures, respectively. We also show that the inclusion of the partonic free-streaming in the early stage allows to delay the start of the hydrodynamical description to comfortable times of the order of 1 fm/c. Free streaming broadens the initial energy-density profile, but generates the initial transverse and elliptic flow. The data may be described equally well when the hydrodynamics is started early, or with a delay due to partonic free-streaming.

Wojciech Broniowski; Mikolaj Chojnacki; Wojciech Florkowski; Adam Kisiel

2008-01-28T23:59:59.000Z

209

Multidimensional study of a 50-MeV, 1500-rad/pulse radiographic linac, using the stagger-tuning concept  

Science Conference Proceedings (OSTI)

Stagger tuning of accelerator cavities, or blocks of cavities, can significantly enhance the achievable charge transfer through an electron linac operating in the stored-energy mode. The output bremsstrahlung flux can be increased over a conventional approach by an order of magnitude without any significant degradation in emittance growth or energy spread. Given a suitable injector, a 1500-rad/pulse, 50-MeV radiographic linac appears to be practical at a 400-MHz operating frequency; a 150-rad/pulse, 50-MeV radiographic linac will operate at 1300 MHz. A multidimensional study was made using the PARMELA code where several parameters, including beam current, synchronous phase angle, and beam radius, were varied while observing the effects on emittance and transmission efficiency.

Owen, R.K.; Fazio, M.V.; Boyd, T.J.

1983-01-01T23:59:59.000Z

210

Baseline Concentrations of Radionuclides and Trace Elements in Soils and Vegetation around the DARHT Facility: Construction Phase (1998)  

Science Conference Proceedings (OSTI)

The Mitigation Action Plan for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory mandates the establishment of baseline concentrations for potential environmental contaminants. To this end, concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, and {sup tot}U and Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl were determined in surface and subsurface soils, sediments, and vegetation (overstory and understory) around the DARHT facility during the construction phase in 1998 (this is the third of a four year baseline study). Also, volatile (VOC) and semivolatile (SVOC) organic compounds were measured in soils and sediments. Most radionuclides and trace metals in soil, sediment, and vegetation were similar to past years at DARHT and were within regional background concentrations. Exceptions were concentrations of {sup 90}Sr, Be, Ba, and total U in some samples--these elements exceeded upper limit regional background concentrations (e.g., >mean plus two std dev). No VOCs and very few SVOCs were detected in soils and sediments at DARHT. Mean ({+-} std dev) radionuclide and trace element concentrations measured in soil, sediment, and vegetation summarized over a three-year period (construction phase) are summarized.

P. R. Fresquez; M. H. Ebinger; H. T. Haagenstad; L. Naranjo, Jr.

1999-12-01T23:59:59.000Z

211

Implications for the electron distribution from the stationary hydrodynamic model of a one-dimensional plasma expansion into vacuum  

SciTech Connect

It is shown that the hydrodynamic model of a one-dimensional collisionless plasma expansion is contained in the kinetic description as a special case. This belongs to a specific choice for the electron distribution function. Moreover, the consequences of the use of the hydrodynamic approach regarding the temporal evolution of the electron phase space density are investigated. It turns out that only the case of a hydrodynamic description with the adiabatic constant {kappa}=3 is physically self-consistent. Numerical simulations confirm this argumentation. The analysis for the case {kappa}=3 is extended to the kinetics of a relativistic electron gas.

Kiefer, Thomas [Friedrich-Schiller-Universitaet Jena, Jena (Germany); Schlegel, Theodor [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Helmholtz Institute Jena, Jena (Germany)

2012-10-15T23:59:59.000Z

212

Low torque hydrodynamic lip geometry for bi-directional rotation seals  

DOE Patents (OSTI)

A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX)

2011-11-15T23:59:59.000Z

213

Low torque hydrodynamic lip geometry for bi-directional rotation seals  

DOE Patents (OSTI)

A hydrodynamically lubricating geometry for the generally circular dynamic sealing lip of rotary seals that are employed to partition a lubricant from an environment. The dynamic sealing lip is provided for establishing compressed sealing engagement with a relatively rotatable surface, and for wedging a film of lubricating fluid into the interface between the dynamic sealing lip and the relatively rotatable surface in response to relative rotation that may occur in the clockwise or the counter-clockwise direction. A wave form incorporating an elongated dimple provides the gradual convergence, efficient impingement angle, and gradual interfacial contact pressure rise that are conducive to efficient hydrodynamic wedging. Skewed elevated contact pressure zones produced by compression edge effects provide for controlled lubricant movement within the dynamic sealing interface between the seal and the relatively rotatable surface, producing enhanced lubrication and low running torque.

Dietle, Lannie L. (Houston, TX); Schroeder, John E. (Richmond, TX)

2009-07-21T23:59:59.000Z

214

Non-Abelian hydrodynamics and the flow of spin in spin-orbit coupled substances  

SciTech Connect

Motivated by the heavy ion collision experiments there is much activity in studying the hydrodynamical properties of non-Abelian (quark-gluon) plasmas. A major question is how to deal with color currents. Although not widely appreciated, quite similar issues arise in condensed matter physics in the context of the transport of spins in the presence of spin-orbit coupling. The key insight is that the Pauli Hamiltonian governing the leading relativistic corrections in condensed matter systems can be rewritten in a language of SU(2) covariant derivatives where the role of the non-Abelian gauge fields is taken by the physical electromagnetic fields: the Pauli system can be viewed as Yang-Mills quantum-mechanics in a 'fixed frame', and it can be viewed as an 'analogous system' for non-Abelian transport in the same spirit as Volovik's identification of the He superfluids as analogies for quantum fields in curved space time. We take a similar perspective as Jackiw and coworkers in their recent study of non-Abelian hydrodynamics, twisting the interpretation into the 'fixed frame' context, to find out what this means for spin transport in condensed matter systems. We present an extension of Jackiw's scheme: non-Abelian hydrodynamical currents can be factored in a 'non-coherent' classical part, and a coherent part requiring macroscopic non-Abelian quantum entanglement. Hereby it becomes particularly manifest that non-Abelian fluid flow is a much richer affair than familiar hydrodynamics, and this permits us to classify the various spin transport phenomena in condensed matter physics in an unifying framework. The 'particle based hydrodynamics' of Jackiw et al. is recognized as the high temperature spin transport associated with semiconductor spintronics. In this context the absence of faithful hydrodynamics is well known, but in our formulation it is directly associated with the fact that the covariant conservation of non-Abelian currents turns into a disastrous non-conservation of the incoherent spin currents of the high temperature limit. We analyze the quantum-mechanical single particle currents of relevance to mesoscopic transport with as highlight the Ahronov-Casher effect, where we demonstrate that the intricacies of the non-Abelian transport render this effect to be much more fragile than its abelian analog, the Ahronov-Bohm effect. We subsequently focus on spin flows protected by order parameters. At present there is much interest in multiferroics where non-collinear magnetic order triggers macroscopic electric polarization via the spin-orbit coupling. We identify this to be a peculiarity of coherent non-Abelian hydrodynamics: although there is no net particle transport, the spin entanglement is transported in these magnets and the coherent spin 'super' current in turn translates into electric fields with the bonus that due to the requirement of single valuedness of the magnetic order parameter a true hydrodynamics is restored. Finally, 'fixed-frame' coherent non-Abelian transport comes to its full glory in spin-orbit coupled 'spin superfluids', and we demonstrate a new effect: the trapping of electrical line charge being a fixed frame, non-Abelian analog of the familiar magnetic flux trapping by normal superconductors. The only known physical examples of such spin superfluids are the {sup 3}He A- and B-phase where unfortunately the spin-orbit coupling is so weak that it appears impossible to observe these effects.

Leurs, B.W.A. [Instituut Lorentz for Theoretical Physics, Leiden University, Leiden (Netherlands)], E-mail: leurs@lorentz.leidenuniv.nl; Nazario, Z.; Santiago, D.I.; Zaanen, J. [Instituut Lorentz for Theoretical Physics, Leiden University, Leiden (Netherlands)

2008-04-15T23:59:59.000Z

215

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":""}]}

216

BETHE-Hydro: An Arbitrary Lagrangian-Eulerian Multi-dimensional Hydrodynamics Code for Astrophysical Simulations  

E-Print Network (OSTI)

In this paper, we describe a new hydrodynamics code for 1D and 2D astrophysical simulations, BETHE-hydro, that uses time-dependent, arbitrary, unstructured grids. The core of the hydrodynamics algorithm is an arbitrary Lagrangian-Eulerian (ALE) approach, in which the gradient and divergence operators are made compatible using the support-operator method. We present 1D and 2D gravity solvers that are finite differenced using the support-operator technique, and the resulting system of linear equations are solved using the tridiagonal method for 1D simulations and an iterative multigrid-preconditioned conjugate-gradient method for 2D simulations. Rotational terms are included for 2D calculations using cylindrical coordinates. We document an incompatibility between a subcell pressure algorithm to suppress hourglass motions and the subcell remapping algorithm and present a modified subcell pressure scheme that avoids this problem. Strengths of this code include a straightforward structure, enabling simple inclusio...

Murphy, Jeremiah W

2008-01-01T23:59:59.000Z

217

Hydrodynamic models for slurry bubble column reactors. Seventh technical progress report, January--March 1996  

DOE Green Energy (OSTI)

The objective of this investigation is to convert our ``learning gas solid-liquid`` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid and particulate phase. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. A hydrodynamic model for multiphase flows, based on the principles of mass, momentum and energy conservation for each phase, was developed and applied to model gas-liquid, gas-liquid-solid fluidization and gas-solid-solid separation. To simulate the industrial slurry bubble column reactors, a computer program based on the hydrodynamic model was written with modules for chemical reactions (e.g. the synthesis of methanol), phase changes and heat exchangers. In the simulations of gas-liquid two phases flow system, the gas hold-ups, computed with a variety of operating conditions such as temperature, pressure, gas and liquid velocities, agree well with the measurements obtained at Air Products` pilot plant. The hydrodynamic model has more flexible features than the previous empirical correlations in predicting the gas hold-up of gas-liquid two-phase flow systems. In the simulations of gas-liquid-solid bubble column reactors with and without slurry circulation, the code computes volume fractions, temperatures and velocity distributions for the gas, the liquid and the solid phases, as well as concentration distributions for the species (CO, H{sub 2}, CH{sub 3}0H, ... ), after startup from a certain initial state. A kinetic theory approach is used to compute a solid viscosity due to particle collisions. Solid motion and gas-liquid-solid mixing are observed on a color PCSHOW movie made from computed time series data. The steady state and time average catalyst concentration profiles, the slurry height and the rates of methanol production agree well with the measurements obtained at an Air Products` pilot plant.

Gidaspow, D.

1996-04-01T23:59:59.000Z

218

Statistical Estimation of Two-Body Hydrodynamic Properties Using System Identification  

E-Print Network (OSTI)

A basic understanding of the hydrodynamic response behavior of the two-body system is important for a wide variety of offshore operations. This is a complex problem and model tests can provide data that in turn can be used to retrieve key 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 parameters useful in design. The computation of the statistical parameters, spectral densities and coherence functions provides an overview of the general response behavior of the system. The statistical analysis also guides the selection of the nonlinear terms that will be used in the reverse multi-input / single-output (R-MI/SO) system identification method in this study. With appropriate linear and nonlinear terms included in the equation of motion, the R-MISO technique is able to estimate the main hydrodynamic parameters that characterize the offshore system. In the past, the R-MISO method was primarily applied to single body systems, while in the current study a ship moored to a fixed barge was investigated. The formulation included frequency-dependant hydrodynamic parameters which were evaluated from the experimental measurements. Several issues specific to this extension were addressed including the computation load, the interpretation of the results and the validation of the model. Only the most important cross-coupling terms were chosen to be kept based on the estimation of their energy. It is shown that both the heading and the loading condition can influence system motion behavior and that the impact of the wave in the gap between the two vessels is important. The coherence was computed to verify goodness-of-fit of the model, the results were overall satisfying.

Xie, Chen

2009-08-01T23:59:59.000Z

219

Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas  

E-Print Network (OSTI)

We employ Navier-Stokes granular hydrodynamics to investigate the long-time behavior of clustering instability in a freely cooling dilute granular gas in two dimensions. We find that, in circular containers, the homogeneous cooling state (HCS) of the gas loses its stability via a sub-critical pitchfork bifurcation. There are no time-independent solutions for the gas density in the supercritical region, and we present analytical and numerical evidence that the gas develops thermal collapse unarrested by heat diffusion. To get more insight, we switch to a simpler geometry of a narrow-sector-shaped container. Here the HCS loses its stability via a transcritical bifurcation. For some initial conditions a time-independent inhomogeneous density profile sets in, qualitatively similar to that previously found in a narrow-channel geometry. For other initial conditions, however, the dilute gas develops thermal collapse unarrested by heat diffusion. We determine the dynamic scalings of the flow close to collapse analytically and verify them in hydrodynamic simulations. The results of this work imply that, in dimension higher than one, Navier-Stokes hydrodynamics of a dilute granular gas is prone to finite-time density blowups. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows.

Itamar Kolvin; Eli Livne; Baruch Meerson

2009-12-03T23:59:59.000Z

220

BETHE-Hydro: An Arbitrary Lagrangian-Eulerian Multi-dimensional Hydrodynamics Code for Astrophysical Simulations  

E-Print Network (OSTI)

In this paper, we describe a new hydrodynamics code for 1D and 2D astrophysical simulations, BETHE-hydro, that uses time-dependent, arbitrary, unstructured grids. The core of the hydrodynamics algorithm is an arbitrary Lagrangian-Eulerian (ALE) approach, in which the gradient and divergence operators are made compatible using the support-operator method. We present 1D and 2D gravity solvers that are finite differenced using the support-operator technique, and the resulting system of linear equations are solved using the tridiagonal method for 1D simulations and an iterative multigrid-preconditioned conjugate-gradient method for 2D simulations. Rotational terms are included for 2D calculations using cylindrical coordinates. We document an incompatibility between a subcell pressure algorithm to suppress hourglass motions and the subcell remapping algorithm and present a modified subcell pressure scheme that avoids this problem. Strengths of this code include a straightforward structure, enabling simple inclusion of additional physics packages, the ability to use a general equation of state, and most importantly, the ability to solve self-gravitating hydrodynamic flows on time-dependent, arbitrary grids. In what follows, we describe in detail the numerical techniques employed and, with a large suite of tests, demonstrate that BETHE-hydro finds accurate solutions with 2$^{nd}$-order convergence.

Jeremiah W. Murphy; Adam Burrows

2008-05-21T23:59:59.000Z

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221

Basic design and hydrodynamic analysis of three-column TLP and comparison with ISSC TLP  

E-Print Network (OSTI)

Three-column TLP is a new design variation of the common four-column TLP. The objective of this study is to find the hydrodynamic feasibility of the three-column TLP. This accomplished by comparing the three-column design to the ISSC TLP. The ISSC TLP is chosen as the parent TLP and the column diameter, distance between column centers, water depth, environment and pontoon dimensions are kept the same for the ISSC TLP. The initial design shows a satisfactory hydrodynamic characteristic set for the three-column. A detailed coupled analysis of the platform is done using Higher Order Boundary Element Application (HOBEM). The wave excitation forces, responses and average drift forces are computed for wave heading 0 degree and 30 degree. A non-linear quasi-static study is done for the tendons. The three-column design is compared with the four-column design and the comparison shows the two are hydrodynamically similar. Three-column TLP can be considered as a viable alternative for four-column TLP.

Sebastian, Abhilash

2000-01-01T23:59:59.000Z

222

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

223

Research on computed tomography reconstructions from one or two radiographs: A report and the application to FXR radiography  

SciTech Connect

This report documents some cooperative research into volumetric image reconstruction from single radiographs. Imaging dynamic events is the most important application for this type of work, but the techniques have possible extensions. Two general objectives guide this work. The first objective is to gain an understanding of the assumptions and limitations of single-view methods for representing internal features. Second, we endeavor to obtain and/or develop techniques for performing image reconstructions with FXR radiographs. If possible, we seek to obtain some quantitative measure of the accuracy of this class of image reconstructions in two respects: (i) in terms of the dimensional accuracy of feature boundaries, and (ii) as pertains to the accuracy of the voxel intensities. Dynamic events are not always self-calibrating, and it is important to establish the reconstruction accuracy of single-view methods for placing bounds on the kinds of conclusions which can be advanced from single-view reconstructed images. Computed tomographic image reconstructions provide dimensional detail of internal structures of objects and provide a measure of the per-voxel attenuation of material in the object. When assumptions behind a reconstruction algorithm are not satisfied, or are satisfied in a limited way, the accuracy of the reconstructed image is compromised. It is the goal of Cr analysis to discern the {open_quotes}real{close_quotes} features of the internals of an object in the midst of a certain level of artifactual content in the image. By understanding the ways in which CT reconstructions from a single radiograph can produce misleading results we hope to develop some measure of the benefits and limitations of single view techniques. 31 refs., 20 figs.

Back, N.; Schneberk, D.; McMillan, C.; Azevedo, S.; Gorvad, M.

1995-01-26T23:59:59.000Z

224

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

SciTech Connect

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

225

Probing the Universe with the Lyman-alpha Forest: I. Hydrodynamics of the Low Density IGM  

E-Print Network (OSTI)

We introduce an efficient and accurate alternative to full hydrodynamic simulations, Hydro-PM (HPM), for the study of the low column density Lyman-alpha forest. It consists of a Particle-Mesh solver, modified to compute, in addition to the gravitational potential, an effective potential due to the gas pressure. Such an effective potential can be computed from the density field because of a tight correlation between density and pressure in the low density limit, which can be calculated for any photo-reionization history by a method outlined in Hui & Gnedin (1997). Such a correlation exists, in part, because of minimal shock-heating in the low density limit. We compare carefully the density and velocity fields as well as absorption spectra, computed using HPM versus hydrodynamic simulations, and find good agreement. We show that HPM is capable of reproducing measurable quantities, such as the column density distribution, computed from full hydrodynamic simulations, to a precision comparable to that of observations. We discuss how, by virtue of its speed and accuracy, HPM can enable us to use the Lyman-alpha forest as a cosmological probe. We also discuss in detail the smoothing of the gas (or baryon) fluctuation relative to that of the dark matter on small scales due to finite gas pressure. It is shown the conventional wisdom that the linear gas fluctuation is smoothed on the Jeans scale is incorrect for general reionization (or reheating) history; the correct linear filtering scale is in general smaller than the Jeans scale after reheating, but larger prior to it. (abridged)

Nickolay Y. Gnedin; Lam Hui

1997-06-20T23:59:59.000Z

226

Stochastic Hard-Sphere Dynamics for Hydrodynamics of Non-Ideal Fluids  

SciTech Connect

A novel stochastic fluid model is proposed with a nonideal structure factor consistent with compressibility, and adjustable transport coefficients. This stochastic hard-sphere dynamics (SHSD) algorithm is a modification of the direct simulation Monte Carlo algorithm and has several computational advantages over event-driven hard-sphere molecular dynamics. Surprisingly, SHSD results in an equation of state and a pair correlation function identical to that of a deterministic Hamiltonian system of penetrable spheres interacting with linear core pair potentials. The fluctuating hydrodynamic behavior of the SHSD fluid is verified for the Brownian motion of a nanoparticle suspended in a compressible solvent.

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

2008-02-26T23:59:59.000Z

227

Knudsen-Hydrodynamic Crossover in Liquid 3He in High Porosity Aerogel  

E-Print Network (OSTI)

We present a combined experimental and theoretical study of the drag force acting on a high porosity aerogel immersed in liquid ${}^3$He 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.

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

2012-01-01T23:59:59.000Z

228

The second order hydrodynamic transport coefficient $?$ for the gluon plasma from the lattice  

E-Print Network (OSTI)

The quark gluon plasma produced in heavy ion collisions behaves like an almost ideal fluid described by viscous hydrodynamics with a number of transport coefficients. The second order coefficient $\\kappa$ is related to a Euclidean correlator of the energy-momentum tensor at vanishing frequency and low momentum. This allows for a lattice determination without maximum entropy methods or modelling, but the required lattice sizes represent a formidable challenge. We calculate $\\kappa$ in leading order lattice perturbation theory and simulations on $120^3\\times 6,8$ lattices with $afuture.

Owe Philipsen; Christian Schäfer

2013-11-26T23:59:59.000Z

229

Coupling atomistic and continuum hydrodynamics through a mesoscopic model: application to liquid water  

E-Print Network (OSTI)

We have conducted a triple-scale simulation of liquid water by concurrently coupling atomistic, mesoscopic, and continuum models of the liquid. The presented triple-scale hydrodynamic solver for molecular liquids enables the insertion of large molecules into the atomistic domain through a mesoscopic region. We show that the triple-scale scheme is robust against the details of the mesoscopic model owing to the conservation of linear momentum by the adaptive resolution forces. Our multiscale approach is designed for molecular simulations of open domains with relatively large molecules, either in the grand canonical ensemble or under non-equilibrium conditions.

Rafael Delgado-Buscalioni; Kurt Kremer; Matej Praprotnik

2009-08-04T23:59:59.000Z

230

Three-Dimensional Smoothed Particle Hydrodynamics Simulation for Liquid Metal Solidification Process  

E-Print Network (OSTI)

The solidification behavior of liquid metal in a container under rapid cooling process is one of the major concerns to be analyzed. In order to analyze its fundamental behavior, a three- dimensional (3D) fluid dynamics simulation was developed using a particle-based method, known as the smoothed particle hydrodynamics (SPH) method. Governing equations that determine the fluid motion and heat transfer involving phase change process are solved by discretizing their gradient and Laplacian term with the moving particles and calculating the interaction with its neighboring particles. The results demonstrate that the SPH mehod can successfully reproduce the behavior and defect prediction of liquid metal solidification process.

S, Raden Ahnaf Faqih

2013-01-01T23:59:59.000Z

231

A Study of the Di-Hadron Angular Correlation Function in Event by Event Ideal Hydrodynamics  

E-Print Network (OSTI)

The di-hadron angular correlation function is computed within boost invariant, ideal hydrodynamics for Au+Au collisions at $\\sqrt{s}_{NN}=200$ GeV using Monte Carlo Glauber fluctuating initial conditions. When $0event by event basis to the initial condition geometrical parameters $\\left\\{\\varepsilon_{2,n}, \\Phi_{2,n} \\right \\}$, respectively. Moreover, the fluctuation of the relative phase between trigger and associated particles, $\\Delta_n =\\Psi_n^t - \\Psi_n^a$, is found to affect the di-hadron angular correlation function when different intervals of transverse momentum are used to define the trigger and the associated hadrons.

R. P. G. Andrade; J. Noronha

2013-05-14T23:59:59.000Z

232

Hydrodynamic models for slurry bubble column reactors. Fourth technical progress report  

DOE Green Energy (OSTI)

The objective of this investigation is to convert our ``learning gas-solid-liquid`` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and volume fractions of gas, liquid and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. The simulation of Air Product methanol reactors described in this paper are continuing. Granular temperatures and viscosities have been computed. Preliminary measurements of granular temperatures using the Air Product catalysts were obtained using our CCD camera.

Gidaspow, D.

1995-07-01T23:59:59.000Z

233

Generalized Hydrodynamic Treatment of the Interplay between Restricted Transport and Catalytic Reactions in Nanoporous Materials  

SciTech Connect

Behavior of catalytic reactions in narrow pores is controlled by a delicate interplay between fluctuations in adsorption-desorption at pore openings, restricted diffusion, and reaction. This behavior is captured by a generalized hydrodynamic formulation of appropriate reaction-diffusion equations (RDE). These RDE incorporate an unconventional description of chemical diffusion in mixed-component quasi-single-file systems based on a refined picture of tracer diffusion for finite-length pores. The RDE elucidate the nonexponential decay of the steady-state reactant concentration into the pore and the non-mean-field scaling of the reactant penetration depth.

Ackerman, David M.; Wang, Jing; Evans, James W.

2012-05-30T23:59:59.000Z

234

Fabrication of Micro and Nanoparticles of Paclitaxel-loaded Poly L Lactide for Controlled Release using Supercritical Antisolvent Method: Effects of Thermodynamics and Hydrodynamics  

E-Print Network (OSTI)

This paper presents the fabrication of controlled release devices for anticancer drug paclitaxel using supercritical antisolvent method. The thermodynamic and hydrodynamic effects during supercritical antisolvent process ...

Lee, Lai Yeng

235

Electrokinetic and hydrodynamic properties of charged-particles systems: From small electrolyte ions to large colloids  

E-Print Network (OSTI)

Dynamic processes in dispersions of charged spherical particles are of importance both in fundamental science, and in technical and bio-medical applications. There exists a large variety of charged-particles systems, ranging from nanometer-sized electrolyte ions to micron-sized charge-stabilized colloids. We review recent advances in theoretical methods for the calculation of linear transport coefficients in concentrated particulate systems, with the focus on hydrodynamic interactions and electrokinetic effects. Considered transport properties are the dispersion viscosity, self- and collective diffusion coefficients, sedimentation coefficients, and electrophoretic mobilities and conductivities of ionic particle species in an external electric field. Advances by our group are also discussed, including a novel mode-coupling-theory method for conduction-diffusion and viscoelastic properties of strong electrolyte solutions. Furthermore, results are presented for dispersions of solvent-permeable particles, and particles with non-zero hydrodynamic surface slip. The concentration-dependent swelling of ionic microgels is discussed, as well as a far-reaching dynamic scaling behavior relating colloidal long- to short-time dynamics.

G. Nägele; M. Heinen; A. J. Banchio; C. Contreras-Aburto

2013-09-13T23:59:59.000Z

236

Note on the hydrodynamic description of thin nematic films: strong anchoring model  

E-Print Network (OSTI)

We discuss the long-wave hydrodynamic model for a thin film of nematic liquid crystal in the limit of strong anchoring at the free surface and at the substrate. We rigorously clarify how the elastic energy enters the evolution equation for the film thickness in order to provide a solid basis for further investigation: several conflicting models exist in the literature that predict qualitatively different behaviour. We consolidate the various approaches and show that the long-wave model derived through an asymptotic expansion of the full nemato-hydrodynamic equations with consistent boundary conditions agrees with the model one obtains by employing a thermodynamically motivated gradient dynamics formulation based on an underlying free energy functional. As a result, we find that in the case of strong anchoring the elastic distortion energy is always stabilising. To support the discussion in the main part of the paper, an appendix gives the full derivation of the evolution equation for the film thickness via asymptotic expansion.

Te-Sheng Lin; Linda J. Cummings; Andrew J. Archer; Lou Kondic; Uwe Thiele

2013-01-17T23:59:59.000Z

237

Oxygen spectral line synthesis: 3D non-LTE with CO5BOLD hydrodynamical model atmospheres  

E-Print Network (OSTI)

In this work we present first results of our current project aimed at combining the 3D hydrodynamical stellar atmosphere approach with non-LTE (NLTE) spectral line synthesis for a number of key chemical species. We carried out a full 3D-NLTE spectrum synthesis of the oxygen IR 777 nm triplet, using a modified and improved version of our NLTE3D package to calculate departure coefficients for the atomic levels of oxygen in a CO5BOLD 3D hydrodynamical solar model atmosphere. Spectral line synthesis was subsequently performed with the Linfor 3D code. In agreement with previous studies, we find that the lines of the oxygen triplet produce deeper cores under NLTE conditions, due to the diminished line source function in the line forming region. This means that the solar oxygen IR 777 nm lines should be stronger in NLTE, leading to negative 3D NLTE-LTE abundance corrections. Qualitatively this result would support previous claims for a relatively low solar oxygen abundance. Finally, we outline several further steps ...

Prakapavicius, D; Kucinskas, A; Ludwig, H -G; Freytag, B; Caffau, E; Cayrel, R

2013-01-01T23:59:59.000Z

238

Event-by-event hydrodynamics and elliptic flow from fluctuating initial states  

Science Conference Proceedings (OSTI)

We develop a framework for event-by-event ideal hydrodynamics to study the differential elliptic flow, which is measured at different centralities in Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC). Fluctuating initial energy density profiles, which here are the event-by-event analogs of the wounded nucleon profiles, are created using a Monte Carlo Glauber model. Using the same event plane method for obtaining v{sub 2} as in the data analysis, we can reproduce both the measured centrality dependence and the p{sub T} shape of charged-particle elliptic flow up to p{sub T}{approx}2 GeV. We also consider the relation of elliptic flow to the initial-state eccentricity using different reference planes and discuss the correlation between the physical event plane and the initial participant plane. Our results demonstrate that event-by-event hydrodynamics with initial-state fluctuations must be accounted for before a meaningful lower limit for viscosity can be obtained from elliptic flow data.

Holopainen, H.; Eskola, K. J. [Department of Physics, Post Office Box 35, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Helsinki Institute of Physics, Post Office Box 64, University of Helsinki, FIN-00014 Helsinki (Finland); Niemi, H. [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Strasse 1, D-60438 Frankfurt am Main (Germany)

2011-03-15T23:59:59.000Z

239

NONLINEAR EVOLUTION OF GLOBAL HYDRODYNAMIC SHALLOW-WATER INSTABILITY IN THE SOLAR TACHOCLINE  

SciTech Connect

We present a fully nonlinear hydrodynamic 'shallow-water' model of the solar tachocline. The model consists of a global spherical shell of differentially rotating fluid, which has a deformable top, thus allowing motions in radial directions along with latitudinal and longitudinal directions. When the system is perturbed, in the course of its nonlinear evolution it can generate unstable low-frequency shallow-water shear modes from the differential rotation, high-frequency gravity waves, and their interactions. Radiative and overshoot tachoclines are characterized in this model by high and low effective gravity values, respectively. Building a semi-implicit spectral scheme containing very low numerical diffusion, we perform nonlinear evolution of shallow-water modes. Our first results show that (1) high-latitude jets or polar spin-up occurs due to nonlinear evolution of unstable hydrodynamic shallow-water disturbances and differential rotation, (2) Reynolds stresses in the disturbances together with changing shell thickness and meridional flow are responsible for the evolution of differential rotation, (3) disturbance energy primarily remains concentrated in the lowest longitudinal wavenumbers, (4) an oscillation in energy between perturbed and unperturbed states occurs due to evolution of these modes in a nearly dissipation-free system, and (5) disturbances are geostrophic, but occasional nonadjustment in geostrophic balance can occur, particularly in the case of high effective gravity, leading to generation of gravity waves. We also find that a linearly stable differential rotation profile remains nonlinearly stable.

Dikpati, Mausumi, E-mail: dikpati@ucar.edu [High Altitude Observatory, National Center for Atmospheric Research, 3080 Center Green, Boulder, CO 80301 (United States)

2012-02-01T23:59:59.000Z

240

Hydrodynamic slip boundary condition at chemically patterned surfaces: A continuum deduction from molecular dynamics  

E-Print Network (OSTI)

We investigate the slip boundary condition for single-phase flow past a chemically patterned surface. Molecular dynamics (MD) simulations show that modulation of fluid-solid interaction along a chemically patterned surface induces a lateral structure in the fluid molecular organization near the surface. Consequently, various forces and stresses in the fluid vary along the patterned surface. Given the presence of these lateral variations, a general scheme is developed to extract hydrodynamic information from MD data. With the help of this scheme, the validity of the Navier slip boundary condition is verified for the chemically patterned surface, where a local slip length can be defined. Based on the MD results, a continuum hydrodynamic model is formulated using the Navier-Stokes equation and the Navier boundary condition, with a slip length varying along the patterned surface. Steady-state velocity fields from continuum calculations are in quantitative agreement with those from MD simulations. It is shown that, when the pattern period is sufficiently small, the solid surface appears to be homogeneous, with an effective slip length that can be controlled by surface patterning. Such a tunable slip length may have important applications in nanofluidics.

Tiezheng Qian; Xiao-Ping Wang; Ping Sheng

2005-02-26T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow  

DOE Green Energy (OSTI)

A hydrodynamic model of two-phase, churn-turbulent flows is being developed using the computational multiphase fluid dynamics (CMFD) code, NPHASE-CMFD. The numerical solutions obtained by this model are compared with experimental data obtained at the TOPFLOW facility of the Institute of Safety Research at the Forschungszentrum Dresden-Rossendorf. The TOPFLOW data is a high quality experimental database of upward, co-current air-water flows in a vertical pipe suitable for validation of computational fluid dynamics (CFD) codes. A five-field CMFD model was developed for the continuous liquid phase and four bubble size groups using mechanistic closure models for the ensemble-averaged Navier-Stokes equations. Mechanistic models for the drag and non-drag interfacial forces are implemented to include the governing physics to describe the hydrodynamic forces controlling the gas distribution. The closure models provide the functional form of the interfacial forces, with user defined coefficients to adjust the force magnitude. An optimization strategy was devised for these coefficients using commercial design optimization software. This paper demonstrates an approach to optimizing CMFD model parameters using a design optimization approach. Computed radial void fraction profiles predicted by the NPHASE-CMFD code are compared to experimental data for four bubble size groups.

Donna Post Guillen

2009-07-01T23:59:59.000Z

242

A fully second order implicit/explicit time integration technique for hydrodynamics plus nonlinear heat conduction problems  

SciTech Connect

We present a fully second order implicit/explicit time integration technique for solving hydrodynamics coupled with nonlinear heat conduction problems. The idea is to hybridize an implicit and an explicit discretization in such a way to achieve second order time convergent calculations. In this scope, the hydrodynamics equations are discretized explicitly making use of the capability of well-understood explicit schemes. On the other hand, the nonlinear heat conduction is solved implicitly. Such methods are often referred to as IMEX methods. The Jacobian-Free Newton Krylov (JFNK) method (e.g. ) is applied to the problem in such a way as to render a nonlinearly iterated IMEX method. We solve three test problems in order to validate the numerical order of the scheme. For each test, we established second order time convergence. We support these numerical results with a modified equation analysis (MEA). The set of equations studied here constitute a base model for radiation hydrodynamics.

Kadioglu, Samet Y. [Multiphysics Methods Group, Reactor Physics Analysis and Design, Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States)], E-mail: Samet.Kadioglu@inl.gov; Knoll, Dana A. [Multiphysics Methods Group, Reactor Physics Analysis and Design, Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States)], E-mail: dana.knoll@inl.gov

2010-05-01T23:59:59.000Z

243

A faster algorithm for smoothed particle hydrodynamics with radiative transfer in the flux-limited diffusion approximation  

E-Print Network (OSTI)

We describe a new, faster implicit algorithm for solving the radiation hydrodynamics equations in the flux-limited diffusion approximation for smoothed particle hydrodynamics. This improves on the method elucidated in Whitehouse & Bate by using a Gauss-Seidel iterative method rather than iterating over the exchange of energy between pairs of particles. The new algorithm is typically many thousands of times faster than the old one, which will enable more complex problems to be solved. The new algorithm is tested using the same tests performed by Turner & Stone for ZEUS-2D, and repeated by Whitehouse & Bate.

Stuart C. Whitehouse; Matthew R. Bate; Joe J. Monaghan

2005-09-28T23:59:59.000Z

244

Assessment of Energy Removal Impacts on Physical Systems: Hydrodynamic Model Domain Expansion and Refinement, and Online Dissemination of Model Results  

Science Conference Proceedings (OSTI)

In this report we describe the 1) the expansion of the PNNL hydrodynamic model domain to include the continental shelf along the coasts of Washington, Oregon, and Vancouver Island; and 2) the approach and progress in developing the online/Internet disseminations of model results and outreach efforts in support of the Puget Sound Operational Forecast System (PS-OPF). Submittal of this report completes the work on Task 2.1.2, Effects of Physical Systems, Subtask 2.1.2.1, Hydrodynamics, for fiscal year 2010 of the Environmental Effects of Marine and Hydrokinetic Energy project.

Yang, Zhaoqing; Khangaonkar, Tarang; Wang, Taiping

2010-08-01T23:59:59.000Z

245

Extended three-dimensional ADCIRC hydrodynamic model to include baroclinic flow and sediment transport  

E-Print Network (OSTI)

The objective of this research is to identify the circulation patterns of the water and sediment fluxes in coastal and estuarine zones, where the shoaling processes correlate with tide generating flow patterns. The research provides a better understanding of the characteristics of spatial and temporal variability of currents. An important deviation from previous research is the inclusion of the baroclinic term, which becomes very important in density driven flows. The understanding of this process provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model is used to calculate the water circulation. The model is based on the three-dimensional (3D) version of Advanced Circulation (AD-CIRC) Hydrodynamic Model with extending the Sediment Transport module. The model is based on the finite element method on unstructured grids. The output of the hydrody-namic model is used to estimate spatial and temporal advections, dispersions and bottom shear stress for the erosion, suspension, deposition and transport of sediment. The model development includes extending the existing three-dimensional (3D) ADCIRC Model with (1) baroclinic forcing term and (2) transport module of suspended and soluble materials. The transport module covers the erosion, material suspension and deposition processes for both cohesive and non-cohesive type sediments. The inclusion of the baroclinic demonstrates the potential of over or underpredicting the total net transport of suspended cohesive sediment under influence of currents. The model provides less than 6% error of theoretical mass conservation for eroded, suspended and deposited sediment material. The inclusion of the baroclinic term in stratified water demonstrates the prevailing longshore sediment transport. It is shown that the model has an application to the transport of the cohesive sediments from the mouth of the Mississippi River along the north shore of the Gulf of Mexico towards and along the Texas coast. The model is also applicable to determine the design erosion thickness of a cap for isolating contaminated dredged material and to evaluate the appro-priate grain size of cap sediments to minimize the erosion.

Pandoe, Wahyu Widodo

2003-05-01T23:59:59.000Z

246

Hydrodynamic/kinetic reactions in liquid-dominated geothermal systems. Final report  

Science Conference Proceedings (OSTI)

A mobile geothermal well-site test unit at the Mercer 2 well in South Brawley, California (Imperial Valley), was constructed and tested. The equipment controlled, monitored, and recorded all process conditions of single- and dual-flash power cycles. Single- and two-phase flashed brine effluents were flowed through piping component test sections to provide hydrodynamic/kinetic data for scale formation. The unit operated at flowrates in excess of 200 gpm and is designed to accommodate flowrates up to 300 gpm. Primary scale formations encountered were those of PbS, Fe/sub 2/ (OH)/sub 3/Cl (iron hydroxychloride), iron chlorides, and non-crystalline forms of SiO/sub 2/. The formation of iron hydroxychloride was due to the unusually high concentration of iron in the wellhead brine (5000 mg/l).

Nesewich, J.P.; Gracey, C.M.

1982-04-01T23:59:59.000Z

247

On the Accuracy of Explicit Finite-Volume Schemes for Fluctuating Hydrodynamics  

E-Print Network (OSTI)

This paper describes the development and analysis of finite-volume methods for the Landau-Lifshitz Navier-Stokes (LLNS) equations and related stochastic partial differential equations in fluid dynamics. The LLNS equations incorporate thermal fluctuations into macroscopic hydrodynamics by the addition of white-noise fluxes whose magnitudes are set by a fluctuation-dissipation relation. Originally derived for equilibrium fluctuations, the LLNS equations have also been shown to be accurate for non-equilibrium systems. Previous studies of numerical methods for the LLNS equations focused primarily on measuring variances and correlations computed at equilibrium and for selected non-equilibrium flows. In this paper, we introduce a more systematic approach based on studying discrete equilibrium structure factors for a broad class of explicit linear finite-volume schemes. This new approach provides a better characterization of the accuracy of a spatio-temporal discretization as a function of wavenumber and frequency, ...

Donev, A; García, A L; Bell, J B

2009-01-01T23:59:59.000Z

248

Galactic scale gas flows in colliding galaxies: 3-Dimensional, N-body/hydrodynamics experiments  

NLE Websites -- All DOE Office Websites (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

249

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

NLE Websites -- All DOE Office Websites (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.

250

Electro-hydrodynamics of binary electrolytes driven by modulated surface potentials  

E-Print Network (OSTI)

We study the electro-hydrodynamics of the Debye screening layer that arises in an aqueous binary solution near a planar insulating wall when applying a spatially modulated AC-voltage. Combining this with first order perturbation theory we establish the governing equations for the full non-equilibrium problem and obtain analytic solutions in the bulk for the pressure and velocity fields of the electrolyte and for the electric potential. We find good agreement between the numerics of the full problem and the analytics of the linear theory. Our work provides the theoretical foundations of circuit models discussed in the literature. The non-equilibrium approach also reveals unexpected high-frequency dynamics not predicted by circuit models.

N. A. Mortensen; L. H. Olesen; L. Belmon; H. Bruus

2004-07-07T23:59:59.000Z

251

Pore-scale modeling of immiscible and miscible fluid flows using smoothed particle hydrodynamics  

Science Conference Proceedings (OSTI)

A numerical model based on smoothed particle hydrodynamics (SPH) was developed and used to simulate immiscible and miscible fluid flows in porous media and to study effects of porous scale heterogeneity and anisotropy on such flows. Models for heterogeneous porous media were generated by using randomly located non-intersecting circular grains of different sizes, and pore scale anisotropy was introduced by randomly inserting non-overlapping particles on either side of the gap between two self-affine fractal curves to create a microfracture. . Different fluid wetting behaviors and surface tensions were modeled using pairwise particle-particle interactions. Particles with different masses and viscosities were used to model multiphase flow. In simulations of miscible fluid flow, particles with variable, composition dependent, masses and viscosities were used. Artificial surface tension effects were avoided by basing the SPH equations on the particle number density.

Tartakovsky, Alexandre M.; Meakin, Paul

2006-10-31T23:59:59.000Z

252

The Quantum State of Classical Matter II: Thermodynamic Equilibrium and Hydrodynamics  

E-Print Network (OSTI)

In the previous companion paper, we proposed a subclass of wavefunctions to describe macroscopic solids that resolved and extended the theory quantum measurement and gave a more specific treatment of quasiparticles. Here we extend these notions to thermalization of solids and gases and to gas state hydrodynamics. This gives a modification of the thermodynamic limit to justify the canonical averages for "typical wavefunctions" without the use of ensembles. The energetic cost of vorticity is contrasted in the classical and ultracold gas limits. From this perspective, we then examine the applicability of thermo and hydro to ultracold gases and compare with the implications of pure state evolution. We illustrate how the proposed quantum limits on viscosity could be reinterpreted in terms of Schr\\"{o}dinger induced evolution of the one-body density function but some history dependent measurable properties should still persist.

Clifford E Chafin

2013-09-04T23:59:59.000Z

253

An efficient approach to unstructured mesh hydrodynamics on the cell broadband engine  

SciTech Connect

Unstructured mesh physics for the Cell Broadband Engine (CBE) has received little or no attention to date, largely because the CBE architecture poses particular challenges for unstructured mesh algorithms. The most common SPU memory management strategies cannot be applied to the irregular memory access patterns of unstructured meshes, and the SPU vector instruction set does not support the indirect addressing needed by connectivity arrays. This paper presents an approach to unstructured mesh physics that addresses these challenges, by creating a new mesh data structure and reorganizing code to give efficient CBE performance. The approach is demonstrated on the FLAG production hydrodynamics code using standard test problems, and results show an average speedup of more than 5x over the original code.

Ferenbaugh, Charles R [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

254

An efficient approach to unstructured mesh hydrodynamics on the cell broadband engine (u)  

SciTech Connect

Unstructured mesh physics for the Cell Broadband Engine (CBE) has received little or no attention to date, largely because the CBE architecture poses particular challenges for unstructured mesh algorithms. SPU memory management strategies such as data preloading cannot be applied to the irregular memory storage patterns of unstructured meshes; and the SPU vector instruction set does not support the indirect addressing needed by connectivity arrays. This paper presents an approach to unstructured mesh physics that addresses these challenges, by creating a new mesh data structure and reorganizing code to give efficient CBE performance. The approach is demonstrated on the FLAG production hydrodynamics code using standard test problems, and results show an average speedup of more than 5x over the original code.

Ferenbaugh, Charles R [Los Alamos National Laboratory

2010-12-14T23:59:59.000Z

255

3D Radiative Hydrodynamics for Disk Stability Simulations: A Proposed Testing Standard and New Results  

E-Print Network (OSTI)

Recent three-dimensional radiative hydrodynamics simulations of protoplanetary disks report disparate disk behaviors, and these differences involve the importance of convection to disk cooling, the dependence of disk cooling on metallicity, and the stability of disks against fragmentation and clump formation. To guarantee trustworthy results, a radiative physics algorithm must demonstrate the capability to handle both the high and low optical depth regimes. We develop a test suite that can be used to demonstrate an algorithm's ability to relax to known analytic flux and temperature distributions, to follow a contracting slab, and to inhibit or permit convection appropriately. We then show that the radiative algorithm employed by Meji\\'a (2004) and Boley et al. (2006) and the algorithm employed by Cai et al. (2006) and Cai et al. (2007, in prep.) pass these tests with reasonable accuracy. In addition, we discuss a new algorithm that couples flux-limited diffusion with vertical rays, we apply the test suite, an...

Boley, Aaron C; Nordlund, Aake; Lord, Jesse

2007-01-01T23:59:59.000Z

256

Nuclear spirals in galaxies: gas response to asymmetric potential. II. Hydrodynamical models  

E-Print Network (OSTI)

Nuclear spirals naturally form as a gas response to non-axisymmetry in the galactic potential, even if the degree of this asymmetry is very small. Linear wave theory well describes weak nuclear spirals, but spirals induced by stronger asymmetries in the potential are clearly beyond the linear regime. Hydrodynamical models indicate spiral shocks in this latter case that, depending on how the spiral intersects the x2 orbits, either get damped, leading to the formation of the nuclear ring, or get strengthened, and propagate towards the galaxy centre. Central massive black hole of sufficient mass can allow the spiral shocks to extend all the way to its immediate vicinity, and to generate gas inflow up to 0.03 M_sun/yr, which coincides with the accretion rates needed to power luminous local Active Galactic Nuclei.

Maciejewski, Witold

2004-01-01T23:59:59.000Z

257

Nuclear spirals in galaxies: gas response to asymmetric potential. II. Hydrodynamical models  

E-Print Network (OSTI)

Nuclear spirals naturally form as a gas response to non-axisymmetry in the galactic potential, even if the degree of this asymmetry is very small. Linear wave theory well describes weak nuclear spirals, but spirals induced by stronger asymmetries in the potential are clearly beyond the linear regime. Hydrodynamical models indicate spiral shocks in this latter case that, depending on how the spiral intersects the x2 orbits, either get damped, leading to the formation of the nuclear ring, or get strengthened, and propagate towards the galaxy centre. Central massive black hole of sufficient mass can allow the spiral shocks to extend all the way to its immediate vicinity, and to generate gas inflow up to 0.03 M_sun/yr, which coincides with the accretion rates needed to power luminous local Active Galactic Nuclei.

Witold Maciejewski

2004-08-05T23:59:59.000Z

258

Hydrodynamic characterization of slurry bubble-column reactors for Fischer-Tropsch synthesis  

DOE Green Energy (OSTI)

In the Fischer-Tropsch approach to indirect liquefaction, slurry bubble-column reactors (SBCRs) are used to convert coal syngas into the desired product. Sandia`s program to develop, implement, and apply diagnostics for hydrodynamic characterization of SBCRs at industrially relevant conditions is discussed.Gas-liquid flow experiments are performed in an industrial-scale stainless steel vessel. Gamma-densitometry tomography (GDT) is applied to make spatially resolved gas holdup measurements. Both water and Drakeol 10 with air sparging are examined at ambient and elevated pressures. Gas holdup increases with gas superficial velocity and pressure, and the GDT values are in good agreement with values from differential pressure (DP) measurements.

Jackson, N.B.; Torczynski, J.R.; Shollenberger, K.A.; O`Hern, T.J.; Adkins, D.R.

1996-08-01T23:59:59.000Z

259

WHAM: A WENO-based general relativistic numerical scheme I: Hydrodynamics  

E-Print Network (OSTI)

Active galactic nuclei, x-ray binaries, pulsars, and gamma-ray bursts are all believed to be powered by compact objects surrounded by relativistic plasma flows driving phenomena such as accretion, winds, and jets. These flows are often accurately modelled by the relativistic magnetohydrodynamics (MHD) approximation. Time-dependent numerical MHD simulations have proven to be especially insightful, but one regime that remains difficult to simulate is when the energy scales (kinetic, thermal, magnetic) within the plasma become disparate. We develop a numerical scheme that significantly improves the accuracy and robustness of the solution in this regime. We use a modified form of the WENO method to construct a finite-volume general relativistic hydrodynamics code called WHAM that converges at fifth order. We avoid (1) field-by-field decomposition by adaptively reducing down to 2-point stencils near discontinuities for a more accurate treatment of shocks, and (2) excessive reduction to low order stencils, as in th...

Tchekhovskoy, Alexander; Narayan, Ramesh

2007-01-01T23:59:59.000Z

260

Variational description of multi-fluid hydrodynamics: Coupling to gauge fields  

E-Print Network (OSTI)

In this work we extend our previously developed formalism of Newtonian multi-fluid hydrodynamics to allow for coupling between the fluids and the electromagnetic and gravitational field. This is achieved within the convective variational principle by using a standard minimal coupling prescription. In addition to the conservation of total energy and momentum, we derive the conservation of canonical vorticity and helicity, which generalize the corresponding conserved quantities of uncharged fluids. We discuss the application of this formalism to electrically conducting systems, magnetohydrodynamics and superconductivity. The equations of electric conductors derived here are more general than those found in the standard description of such systems, in which the effect of entrainment is overlooked, despite the fact that it will generally be present in any conducting multi-constituent system.

Reinhard Prix

2005-03-29T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Formation of singularities in solutions to the compressible radiation hydrodynamics equations with vacuum  

E-Print Network (OSTI)

We study the Cauchy problem for multi-dimensional compressible radiation hydrodynamics equations with vacuum. First, we present some sufficient conditions on the blow-up of smooth solutions in multi-dimensional space. Then, we obtain the invariance of the support of density for the smooth solutions with compactly supported initial mass density by the property of the system under the vacuum state. Based on the above-mentioned results, we prove that we cannot get a global classical solution, no matter how small the initial data are, as long as the initial mass density is of compact support. Finally, we will see that some of the results that we obtained are still valid for the isentropic flows with degenerate viscosity coefficients as well as 1-D case.

Yachun Li; Shengguo Zhu

2013-09-28T23:59:59.000Z

262

A radiation-hydrodynamics scheme valid from the transport to the diffusion limit  

E-Print Network (OSTI)

We present in this paper the numerical treatment of the coupling between hydrodynamics and radiative transfer. The fluid is modeled by classical conservation laws (mass, momentum and energy) and the radiation by the grey moment $M_1$ system. The scheme introduced is able to compute accurate numerical solution over a broad class of regimes from the transport to the diffusive limits. We propose an asymptotic preserving modification of the HLLE scheme in order to treat correctly the diffusion limit. Several numerical results are presented, which show that this approach is robust and have the correct behavior in both the diffusive and free-streaming limits. In the last numerical example we test this approach on a complex physical case by considering the collapse of a gas cloud leading to a proto-stellar structure which, among other features, exhibits very steep opacity gradients.

E. Audit; P. Charrier; J. -P. Chièze; B. Dubroca

2002-06-17T23:59:59.000Z

263

Formation of singularities in solutions to ideal hydrodynamics of freely cooling inelastic gases  

E-Print Network (OSTI)

We consider solutions to the hyperbolic system of equations of ideal granular hydrodynamics with conserved mass, total energy and finite momentum of inertia and prove that these solutions generically lose the initial smoothness within a finite time in any space dimension $n$ for the adiabatic index $\\gamma \\le 1+\\frac{2}{n}.$ Further, in the one-dimensional case we introduce a solution depending only on the spatial coordinate outside of a ball containing the origin and prove that this solution under rather general assumptions on initial data cannot be global in time too. Then we construct an exact axially symmetric solution with separable time and space variables having a strong singularity in the density component beginning from the initial moment of time, whereas other components of solution are initially continuous.

Olga Rozanova

2011-07-02T23:59:59.000Z

264

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

DOE Green Energy (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

265

OTEC cold water pipe: a survey of available shell analysis computer programs and implications of hydrodynamic loadings  

DOE Green Energy (OSTI)

The design and analysis of the cold water pipe (CWP) is one of the most important technological problems to be solved in the OTEC ocean engineering program. Analytical computer models have to be developed and verified in order to provide an engineering approach for the OTEC CWP with regards to environmental factors such as waves, currents, platform motions, etc., and for various structural configurations and materials such as rigid wall CWP, compliant CWP, stockade CWP, etc. To this end, Analysis and Technology, Inc. has performed a review and evaluation of shell structural analysis computer programs applicable to the design of an OTEC CWP. Included in this evaluation are discussions of the hydrodynamic flow field, structure-fluid interaction and the state-of-the-art analytical procedures for analysis of offshore structures. The analytical procedures which must be incorporated into the design of a CWP are described. A brief review of the state-of-the-art for analysis of offshore structures and the need for a shell analysis for the OTEC CWP are included. A survey of available shell computer programs, both special purpose and general purpose, and discussions of the features of these dynamic shell programs and how the hydrodynamic loads are represented within the computer programs are included. The hydrodynamic loads design criteria for the CWP are described. An assessment of the current state of knowledge for hydrodynamic loads is presented. (WHK)

Pompa, J.A.; Allik, H.; Webman, K.; Spaulding, M.

1979-02-01T23:59:59.000Z

266

Effect of the Coriolis Force on the Hydrodynamics of Colliding Wind Binaries  

E-Print Network (OSTI)

Using fully three-dimensional hydrodynamic simulations, we investigate the effect of the Coriolis force on the hydrodynamic and observable properties of colliding wind binary systems. To make the calculations tractable, we assume adiabatic, constant velocity winds. The neglect of radiative driving, gravitational deceleration, and cooling limit the application of our models to real systems. However, these assumptions allow us to isolate the effect of the Coriolis force, and by simplifying the calculations, allow us to use a higher resolution (up to 640^3) and to conduct a larger survey of parameter space. We study the dynamics of collidng winds with equal mass loss rates and velocities emanating from equal mass stars on circular orbits, with a range of values for the ratio of the wind to orbital velocity. We also study the dynamics of winds from stars on elliptical orbits and with unequal strength winds. Orbital motion of the stars sweeps the shocked wind gas into an Archimedean spiral, with asymmetric shock strengths and therefore unequal postshock temperatures and densities in the leading and trailing edges of the spiral. We observe the Kelvin-Helmholtz instability at the contact surface between the shocked winds in systems with orbital motion even when the winds are identical. The change in shock strengths caused by orbital motion increases the volume of X-ray emitting post-shock gas with T > 0.59 keV by 63% for a typical system as the ratio of wind velocity to orbital velocity decreases to V_w/V_o = 2.5. This causes increased free-free emission from systems with shorter orbital periods and an altered time-dependence of the wind attenuation. We comment on the importance of the effects of orbital motion on the observable properties of colliding wind binaries.

M. Nicole Lemaster; James M. Stone; Thomas A. Gardiner

2007-02-16T23:59:59.000Z

267

A Rigid-Field Hydrodynamics approach to modeling the magnetospheres of massive stars  

E-Print Network (OSTI)

We introduce a new Rigid-Field Hydrodynamics approach to modeling the magnetospheres of massive stars in the limit of very-strong magnetic fields. Treating the field lines as effectively rigid, we develop hydrodynamical equations describing the 1-dimensional flow along each, subject to pressure, radiative, gravitational, and centrifugal forces. We solve these equations numerically for a large ensemble of field lines, to build up a 3-dimensional time-dependent simulation of a model star with parameters similar to the archetypal Bp star sigma Ori E. Since the flow along each field line can be solved for independently of other field lines, the computational cost of this approach is a fraction of an equivalent magnetohydrodynamical treatment. The simulations confirm many of the predictions of previous analytical and numerical studies. Collisions between wind streams from opposing magnetic hemispheres lead to strong shock heating. The post-shock plasma cools initially via X-ray emission, and eventually accumulates into a warped, rigidly rotating disk defined by the locus of minima of the effective (gravitational plus centrifugal) potential. But a number of novel results also emerge. For field lines extending far from the star, the rapid area divergence enhances the radiative acceleration of the wind, resulting in high shock velocities (up to ~3,000 km/s) and hard X-rays. Moreover, the release of centrifugal potential energy continues to heat the wind plasma after the shocks, up to temperatures around twice those achieved at the shocks themselves. Finally, in some circumstances the cool plasma in the accumulating disk can oscillate about its equilibrium position, possibly due to radiative cooling instabilities in the adjacent post-shock regions.

R. H. D. Townsend; S. P. Owocki; A. ud-Doula

2007-09-05T23:59:59.000Z

268

Laser-Driven Hydrodynamic Experiments in the Turbulent Plasma Regime: from OMEGA to NIF  

Science Conference Proceedings (OSTI)

There is a great deal of interest in studying the evolution of hydrodynamic phenomena in high energy density plasmas that have transitioned beyond the initial phases of instability into a fully developed turbulent state. Motivation for this study arises both in fusion plasmas as well as in numerous astrophysical applications where the understanding of turbulent mixing is essential. Double-shell ignition targets, for example, are subject to large growth of short wavelength perturbations on both surfaces of the high-Z inner shell. These perturbations, initiated by Richtmyer-Meshkov and Rayleigh-Taylor instabilities, can transition to a turbulent state and will lead to deleterious mixing of the cooler shell material with the hot burning fuel. In astrophysical plasmas, due to the extremely large scale, turbulent hydrodynamic mixing is also of widespread interest. The radial mixing that occurs in the explosion phase of core-collapse supernovae is an example that has received much attention in recent years and yet remains only poorly understood. In all of these cases, numerical simulation of the flow field is very difficult due to the large Reynolds number and corresponding wide range of spatial scales characterizing the plasma. Laboratory experiments on high energy density facilities that can access this regime are therefore of great interest. Experiments exploring the transition to turbulence that are currently being conducted on the Omega laser will be described. We will also discuss experiments being planned for the initial commissioning phases of the NIF as well as the enhanced experimental parameter space that will become available, as additional quads are made operational.

Robey, H F; Miles, A R; Hansen, J F; Blue, B E; Drake, R P

2003-08-25T23:59:59.000Z

269

Formation of Nuclear Disks and Supermassive Black Hole Binaries in Multi-Scale Hydrodynamical Galaxy Mergers  

E-Print Network (OSTI)

(Abridged) We review the results of the first multi-scale, hydrodynamical simulations of mergers between galaxies with central supermassive black holes (SMBHs) to investigate the formation of SMBH binaries in galactic nuclei. We demonstrate that strong gas inflows produce nuclear disks at the centers of merger remnants whose properties depend sensitively on the details of gas thermodynamics. In numerical simulations with parsec-scale spatial resolution in the gas component and an effective equation of state appropriate for a starburst galaxy, we show that a SMBH binary forms very rapidly, less than a million years after the merger of the two galaxies. Binary formation is significantly suppressed in the presence of a strong heating source such as radiative feedback by the accreting SMBHs. We also present preliminary results of numerical simulations with ultra-high spatial resolution of 0.1 pc in the gas component. These simulations resolve the internal structure of the resulting nuclear disk down to parsec scales and demonstrate the formation of a central massive object (~ 10^8 Mo) by efficient angular momentum transport. This is the first time that a radial gas inflow is shown to extend to parsec scales as a result of the dynamics and hydrodynamics involved in a galaxy merger, and has important implications for the fueling of SMBHs. Due to the rapid formation of the central clump, the density of the nuclear disk decreases significantly in its outer region, reducing dramatically the effect of dynamical friction and leading to the stalling of the two SMBHs at a separation of ~1 pc. We discuss how the orbital decay of the black holes might continue in a more realistic model which incorporates star formation and the multi-phase nature of the ISM.

Lucio Mayer; Stelios Kazantzidis; Andres Escala

2008-07-22T23:59:59.000Z

270

Magnetic Resonance-Based Treatment Planning for Prostate Intensity-Modulated Radiotherapy: Creation of Digitally Reconstructed Radiographs  

SciTech Connect

Purpose: To develop a technique to create magnetic resonance (MR)-based digitally reconstructed radiographs (DRR) for initial patient setup for routine clinical applications of MR-based treatment planning for prostate intensity-modulated radiotherapy. Methods and Materials: Twenty prostate cancer patients' computed tomography (CT) and MR images were used for the study. Computed tomography and MR images were fused. The pelvic bony structures, including femoral heads, pubic rami, ischium, and ischial tuberosity, that are relevant for routine clinical patient setup were manually contoured on axial MR images. The contoured bony structures were then assigned a bulk density of 2.0 g/cm{sup 3}. The MR-based DRRs were generated. The accuracy of the MR-based DDRs was quantitatively evaluated by comparing MR-based DRRs with CT-based DRRs for these patients. For each patient, eight measuring points on both coronal and sagittal DRRs were used for quantitative evaluation. Results: The maximum difference in the mean values of these measurement points was 1.3 {+-} 1.6 mm, and the maximum difference in absolute positions was within 3 mm for the 20 patients investigated. Conclusions: Magnetic resonance-based DRRs are comparable to CT-based DRRs for prostate intensity-modulated radiotherapy and can be used for patient treatment setup when MR-based treatment planning is applied clinically.

Chen, Lili [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)]. E-mail: lili.chen@fccc.edu; Nguyen, Thai-Binh [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Jones, Elan [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Chen Zuoqun [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Luo Wei [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Wang Lu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Price, Robert A. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Pollack, Alan [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Ma, C.-M. Charlie [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

2007-07-01T23:59:59.000Z

271

Frequency-dependent hydrodynamic inductance and the determination of the thermal and quantum noise of a superfluid gyroscope  

SciTech Connect

We reexamine mass flow in a superfluid gyroscope containing a superfluid Josephson weak link. We introduce a frequency-dependent hydrodynamic inductance to account for an oscillatory flow of the normal fluid component in the sensing loop. With this hydrodynamic inductance, we derive the thermal phase noise, and hence the thermal rotational noise of the gyroscope. We examine the thermodynamic stability of the system based on an analysis of the free energy. We derive a quantum phase noise, which is analogous to the zero-point motion of a simple harmonic oscillator. The configuration of the studied gyroscope is analogous to a conventional superconducting RF SQUID. We show that the gyroscope has very low intrinsic noise (1.9x10{sup -13} rad s{sup -1}/{radical}(Hz)), and it can potentially be applied to study general relativity, Earth science, and to improve global positioning systems (GPS)

Chui, Talso; Penanen, Konstantin [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2005-04-01T23:59:59.000Z

272

Radiation Hydrodynamics in Kerr Spacetime: Equations without Coordinate Singularity at the Event Horizon  

E-Print Network (OSTI)

Equations of fully general relativistic radiation hydrodynamics around a rotating black hole are derived by using the Kerr-Schild coordinate where there is no coordinate singularity at the event horizon. Since the radiation interacts with matter moving with relativistic velocities near the event horizon, the interplay between the radiation and the matter should be described fully relativistically. In the formalism used in this study, while the interactions between matter and radiation are introduced in the comoving frame, the equations and the equations and the derivatives for the description of the global evolution of both matter and the radiation are given in the Kerr-Schild frame (KSF) which is a frame fixed to the coordinate describing the central black hole. As a frame fixed to the coordinate, we use the locally non-rotating reference frame (LNRF) representing a radially falling frame when the Kerr-Schild coordinate is used. Around the rotating black hole, both the matter and the radiation are affected by the frame-dragging effects.

Rohta Takahashi

2007-10-18T23:59:59.000Z

273

Smoothed particle hydrodynamics model of non-aqueous phase liquid flow and dissolution  

Science Conference Proceedings (OSTI)

A smoothed particle hydrodynamics model was developed to simulate the flow of mixtures of aqueous and non-aqueous phase liquids in porous media and the dissolution of the non-aqueous phase in the aqueous phase. The model was used to study the effects of pore-scale heterogeneity and anisotropy on the steady state dense non-aqueous phase liquid (DNAPL) saturation when gravity driven DNAPL displaces water from initially water saturated porous media. Pore-scale anisotropy was created by using co-oriented non overlapping elliptically shaped grains to represent the porous media. After a steady state DNAPL saturation was reached, water was injected until a new steady state DNAPL saturation was reached. The amount of trapped DNAPL was found to be greater when DNAPL is displaced in the direction of the major axes of the soil grains than when it is displaced in the direction of the minor axes of the soil grains. The amount of trapped DNAPL was also found to increase with decreasing initial saturation of the continuous DNAPL phase. For the conditions used in our simulations, the saturation of the trapped NAPL with a smaller initial DNAPL saturation was more than 3 times larger than the amount of trapped DNAPL with a larger initial saturation. These simulations were carried out assuming that the DNAPL did not dissolve in water. Simulations including the effect of dissolution of DNAPL in the aqueous phase were also performed, and effective (macroscopic) mass transfer coefficients were determined.

Tartakovsky, Alexandre M.; Meakin, Paul; Ward, Anderson L.

2009-01-01T23:59:59.000Z

274

Hydrodynamic models for slurry bubble column reactors. Sixth technical progress report  

DOE Green Energy (OSTI)

The objective of this investigation is to convert the gas-solid-liquid fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. This report presents measurements of granular temperature of Air Products catalyst. The report is in the form of a preliminary paper, entitled ``Dynamics of Liquid-Solid Fluidized Beds with Small Catalyst Particles.`` The principal results are as follows: (1) For the liquid-solid system the granular temperature is much smaller than for a corresponding gas-solid system. This may be due to the larger viscosity of the liquid in comparison to air. (2) The collisional viscosity of the catalyst is correspondingly much smaller than that of catalyst particles in the air. (3) The dominant frequency of density oscillations is near two Hertz, as expected for a gas-solid fluidized bed. There exists a link between this low frequency and the high frequency of catalyst particle oscillations. The Air Products fluidized bed reactor is designed to produce methanol and synthetic fuels from synthesis gas.

Gidaspow, D.

1996-01-01T23:59:59.000Z

275

Smolt Responses to Hydrodynamic Conditions in Forebay Flow Nets of Surface Flow Outlets, 2007  

DOE Green Energy (OSTI)

This study provides information on juvenile salmonid behaviors at McNary and The Dalles dams that can be used by the USACE, fisheries resource managers, and others to support decisions on long-term measures to enhance fish passage. We researched smolt movements and ambient hydrodynamic conditions using a new approach combining simultaneous acoustic Doppler current profiler (ADCP) and acoustic imaging device (AID) measurements at surface flow outlets (SFO) at McNary and The Dalles dams on the Columbia River during spring and summer 2007. Because swimming effort vectors could be computed from the simultaneous fish and flow data, fish behavior could be categorized as passive, swimming against the flow (positively rheotactic), and swimming with the flow (negatively rheotactic). We present bivariate relationships to provide insight into fish responses to particular hydraulic variables that engineers might consider during SFO design. The data indicate potential for this empirical approach of simultaneous water/fish measurements to lead to SFO design guidelines in the future.

Johnson, Gary E.; Richmond, Marshall C.; Hedgepeth, J. B.; Ploskey, Gene R.; Anderson, Michael G.; Deng, Zhiqun; Khan, Fenton; Mueller, Robert P.; Rakowski, Cynthia L.; Sather, Nichole K.; Serkowski, John A.; Steinbeck, John R.

2009-04-01T23:59:59.000Z

276

Accretion of low angular momentum material onto black holes: 2D hydrodynamical inviscid case  

E-Print Network (OSTI)

We report on the first phase of our study of slightly rotating accretion flows onto black holes. We consider inviscid accretion flows with a spherically symmetric density distribution at the outer boundary, but with spherical symmetry broken by the introduction of a small, latitude-dependent angular momentum. We study accretion flows by means of numerical 2D, axisymmetric, hydrodynamical simulations. Our main result is that the properties of the accretion flow do not depend as much on the outer boundary conditions (i.e., the amount as well as distribution of the angular momentum) as on the geometry of the non-accreting matter. The material that has too much angular momentum to be accreted forms a thick torus near the equator. Consequently, the geometry of the polar region, where material is accreted (the funnel), and the mass accretion rate through it are constrained by the size and shape of the torus. Our results show one way in which the mass accretion rate of slightly rotating gas can be significantly reduced compared to the accretion of non-rotating gas (i.e., the Bondi rate), and set the stage for calculations that will take into account the transport of angular momentum and energy.

D. Proga; M. C. Begelman

2002-08-28T23:59:59.000Z

277

Three-dimensional hydrodynamic simulations of the combustion of a neutron star into a quark star  

Science Conference Proceedings (OSTI)

We present three-dimensional numerical simulations of turbulent combustion converting a neutron star into a quark star. Hadronic matter, described by a microphysical finite-temperature equation of state, is converted into strange quark matter. We assume this phase, represented by a bag-model equation of state, to be absolutely stable. Following the example of thermonuclear burning in white dwarfs leading to type Ia supernovae, we treat the conversion process as a potentially turbulent deflagration. Solving the nonrelativistic Euler equations using established numerical methods we conduct large eddy simulations including an elaborate subgrid scale model, while the propagation of the conversion front is modeled with a level-set method. Our results show that for large parts of the parameter space the conversion becomes turbulent and therefore significantly faster than in the laminar case. Despite assuming absolutely stable strange quark matter, in our hydrodynamic approximation an outer layer remains in the hadronic phase, because the conversion front stops when it reaches conditions under which the combustion is no longer exothermic.

Herzog, Matthias; Roepke, Friedrich K. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85741 Garching (Germany); Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg, Emil-Fischer-Str. 31, D-97074 Wuerzburg (Germany)

2011-10-15T23:59:59.000Z

278

Radiation hydrodynamics with Adaptive Mesh Refinement and application to prestellar core collapse. I Methods  

E-Print Network (OSTI)

Radiative transfer has a strong impact on the collapse and the fragmentation of prestellar dense cores. We present the radiation-hydrodynamics solver we designed for the RAMSES code. The method is designed for astrophysical purposes, and in particular for protostellar collapse. We present the solver, using the co-moving frame to evaluate the radiative quantities. We use the popular flux limited diffusion approximation, under the grey approximation (one group of photon). The solver is based on the second-order Godunov scheme of RAMSES for its hyperbolic part, and on an implicit scheme for the radiation diffusion and the coupling between radiation and matter. We report in details our methodology to integrate the RHD solver into RAMSES. We test successfully the method against several conventional tests. For validation in 3D, we perform calculations of the collapse of an isolated 1 M_sun prestellar dense core, without rotation. We compare successfully the results with previous studies using different models for r...

Commercon, Benoit; Audit, Edouard; Hennebelle, Patrick; Chabrier, Gilles

2011-01-01T23:59:59.000Z

279

A Two-Dimensional MagnetoHydrodynamics Scheme for General Unstructured Grids  

E-Print Network (OSTI)

We report a new finite-difference scheme for two-dimensional magnetohydrodynamics (MHD) simulations, with and without rotation, in unstructured grids with quadrilateral cells. The new scheme is implemented within the code VULCAN/2D, which already includes radiation-hydrodynamics in various approximations and can be used with arbitrarily moving meshes (ALE). The MHD scheme, which consists of cell-centered magnetic field variables, preserves the nodal finite difference representation of $div(\\bB)$ by construction, and therefore any initially divergence-free field remains divergence-free through the simulation. In this paper, we describe the new scheme in detail and present comparisons of VULCAN/2D results with those of the code ZEUS/2D for several one-dimensional and two-dimensional test problems. The code now enables two-dimensional simulations of the collapse and explosion of the rotating, magnetic cores of massive stars. Moreover, it can be used to simulate the very wide variety of astrophysical problems for which multi-D radiation-magnetohydrodynamics (RMHD) is relevant.

Eli Livne; Luc Dessart; Adam Burrows; Casey A. Meakin

2007-02-18T23:59:59.000Z

280

Scaling relations and mass bias in hydrodynamical f(R) gravity simulations of galaxy clusters  

E-Print Network (OSTI)

We investigate the impact of chameleon-type f(R) gravity models on the properties of galaxy clusters and groups. Our f(R) simulations follow for the first time also the hydrodynamics of the intracluster and intragroup medium. This allows us to assess how f(R) gravity alters the X-ray scaling relations of clusters and how hydrostatic and dynamical mass estimates are biased when modifications of gravity are ignored in their determination. We find that velocity dispersions and intracluster medium temperatures are both increased by up to 1/3 in f(R) gravity in low-mass halos, while the difference disappears in massive objects. The mass scale of the transition depends on the background value f_R0 of the scalar degree of freedom. These changes in temperature and velocity dispersion alter the mass-temperature and X-ray luminosity-temperature scaling relations and bias dynamical and hydrostatic mass estimates that do not explicitly account for modified gravity towards higher values. Recently, a relative enhancement o...

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2013-01-01T23:59:59.000Z

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281

Trans-Planckian physics and signature change events in Bose gas hydrodynamics  

E-Print Network (OSTI)

We present an example of emergent spacetime as the hydrodynamic limit of a more fundamental microscopic theory. The low-energy, long-wavelength limit in our model is dominated by collective variables that generate an effective Lorentzian metric. This system naturally exhibits a microscopic mechanism allowing us to perform controlled signature change between Lorentzian and Riemannian geometries. We calculate the number of particles produced from a finite-duration Euclidean-signature event, where we take the position that to a good approximation the dynamics is dominated by the evolution of the linearized perturbations, as suggested by Calzetta and Hu [Phys. Rev. A 68 (2003) 043625]. We adapt the ideas presented by Dray et al. [Gen. Rel. Grav. 23 (1991) 967], such that the field and its canonical momentum are continuous at the signature-change event. We investigate the interplay between the underlying microscopic structure and the emergent gravitational field, focussing on its impact on particle production in the ultraviolet regime. In general, this can be thought of as the combination of trans-Planckian physics and signature-change physics. Further we investigate the possibility of using the proposed signature change event as an amplifier for analogue "cosmological particle production" in condensed matter experiments.

Silke Weinfurtner; Angela White; Matt Visser

2007-03-23T23:59:59.000Z

282

WHAM: A WENO-based general relativistic numerical scheme I: Hydrodynamics  

E-Print Network (OSTI)

Active galactic nuclei, x-ray binaries, pulsars, and gamma-ray bursts are all believed to be powered by compact objects surrounded by relativistic plasma flows driving phenomena such as accretion, winds, and jets. These flows are often accurately modelled by the relativistic magnetohydrodynamics (MHD) approximation. Time-dependent numerical MHD simulations have proven to be especially insightful, but one regime that remains difficult to simulate is when the energy scales (kinetic, thermal, magnetic) within the plasma become disparate. We develop a numerical scheme that significantly improves the accuracy and robustness of the solution in this regime. We use a modified form of the WENO method to construct a finite-volume general relativistic hydrodynamics code called WHAM that converges at fifth order. We avoid (1) field-by-field decomposition by adaptively reducing down to 2-point stencils near discontinuities for a more accurate treatment of shocks, and (2) excessive reduction to low order stencils, as in the standard WENO formalism, by maintaining high order accuracy in smooth monotonic flows. Our scheme performs the proper surface integral of the fluxes, converts cell averaged conserved quantities to point conserved quantities before performing the reconstruction step, and correctly averages all source terms. We demonstrate that the scheme is robust in strong shocks, very accurate in smooth flows, and maintains accuracy even when the energy scales in the flow are highly disparate.

Alexander Tchekhovskoy; Jonathan C. McKinney; Ramesh Narayan

2007-04-20T23:59:59.000Z

283

Directionally Unsplit Hydrodynamic Schemes with Hybrid MPI/OpenMP/GPU Parallelization in AMR  

E-Print Network (OSTI)

We present the implementation and performance of a class of directionally unsplit Riemann-solver-based hydrodynamic schemes on Graphic Processing Units (GPU). These schemes, including the MUSCL-Hancock method, a variant of the MUSCL-Hancock method, and the corner-transport-upwind method, are embedded into the adaptive-mesh-refinement (AMR) code GAMER. Furthermore, a hybrid MPI/OpenMP model is investigated, which enables the full exploitation of the computing power in a heterogeneous CPU/GPU cluster and significantly improves the overall performance. Performance benchmarks are conducted on the Dirac GPU cluster at NERSC/LBNL using up to 32 Tesla C2050 GPUs. A single GPU achieves speed-ups of 101(25) and 84(22) for uniform-mesh and AMR simulations, respectively, as compared with the performance using one(four) CPU core(s), and the excellent performance persists in multi-GPU tests. In addition, we make a direct comparison between GAMER and the widely-adopted CPU code Athena (Stone et al. 2008) in adiabatic hydro...

Schive, Hsi-Yu; Chiueh, Tzihong

2011-01-01T23:59:59.000Z

284

A Two-moment Radiation Hydrodynamics Module in Athena Using a Time-explicit Godunov Method  

E-Print Network (OSTI)

We describe a module for the Athena code that solves the gray equations of radiation hydrodynamics (RHD), based on the first two moments of the radiative transfer equation. We use a combination of explicit Godunov methods to advance the gas and radiation variables including the non-stiff source terms, and a local implicit method to integrate the stiff source terms. We adopt the M1 closure relation and include all leading source terms. We employ the reduced speed of light approximation (RSLA) with subcycling of the radiation variables in order to reduce computational costs. Our code is dimensionally unsplit in one, two, and three space dimensions and is parallelized using MPI. The streaming and diffusion limits are well-described by the M1 closure model, and our implementation shows excellent behavior for a problem with a concentrated radiation source containing both regimes simultaneously. Our operator-split method is ideally suited for problems with a slowly varying radiation field and dynamical gas flows, i...

Skinner, M Aaron

2013-01-01T23:59:59.000Z

285

Salinity and hydrodynamics of the Holocene and upper Pleistocene beneath the Louisiana wetlands from electrical measurements  

Science Conference Proceedings (OSTI)

A conceptual hydrodynamic model in the Holocene and upper Pleistocene beneath the Louisiana wetlands is described in terms of safety distributions. Porewater safety is calculated from electrical measurements, including resistivity soundings, electric logs, and electromagnetic profiling. Electrical measurements support the primary, basin-wide groundwater flow model; however, the data also indicate secondary contributions from expulsion of fluids under geopressure along active growth faults and from original waters of deposition. Expulsion of water from growth faults has been described previously for deeper sections of the Pleistocene, but has not been reported for the Holocene or upper Pleistocene beneath the Louisiana wetlands. Porewater chemistry variations beneath the coastal wetlands are a consequence of the following (in order of importance): (1) environment of deposition; (2) a basin-wide, regional flow system; (3) expulsion from deep-seated growth faults; and (4) pore water extrusion due to compaction. Water chemistry in Holocene clays and muds is influenced primarily by the deposition environment In Pleistocene sands, the chemistry is a function of the other three factors.

McGinnis, L.D.; Thompson, M.D.; Kuecher, G.J.; Wilkey, P.L. [Argonne National Lab., IL (United States); Isaacson, H.R. [Gas Research Inst., Chicago, IL (United States)

1995-06-01T23:59:59.000Z

286

Efficient Calculation of Dewatered and Entrapped Areas Using Hydrodynamic Modeling and GIS  

Science Conference Proceedings (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

287

RADIATION-HYDRODYNAMIC MODELS OF THE EVOLVING CIRCUMSTELLAR MEDIUM AROUND MASSIVE STARS  

SciTech Connect

We study the evolution of the interstellar and circumstellar media around massive stars (M {>=} 40 M{sub sun}) from the main sequence (MS) through to the Wolf-Rayet (WR) stage by means of radiation-hydrodynamic simulations. We use publicly available stellar evolution models to investigate the different possible structures that can form in the stellar wind bubbles around WR stars. We find significant differences between models with and without stellar rotation, and between models from different authors. More specifically, we find that the main ingredients in the formation of structures in the WR wind bubbles are the duration of the red supergiant (or luminous blue variable) phase, the amount of mass lost, and the wind velocity during this phase, in agreement with previous authors. Thermal conduction is also included in our models. We find that MS bubbles with thermal conduction are slightly smaller, due to extra cooling which reduces the pressure in the hot, shocked bubble, but that thermal conduction does not appear to significantly influence the formation of structures in post-MS bubbles. Finally, we study the predicted X-ray emission from the models and compare our results with observations of the WR bubbles S 308, NGC 6888, and RCW 58. We find that bubbles composed primarily of clumps have reduced X-ray luminosity and very soft spectra, while bubbles with shells correspond more closely to observations.

Toala, J. A.; Arthur, S. J. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Campus Morelia, Apartado Postal 3-72, 58090, Morelia, Michoacan (Mexico)

2011-08-20T23:59:59.000Z

288

Coupled hydrodynamic-structural analysis of an integral flowing sodium test loop in the TREAT reactor  

SciTech Connect

A hydrodynamic-structural response analysis of the Mark-IICB loop was performed for the TREAT (Transient Reactor Test Facility) test AX-1. Test AX-1 is intended to provide information concerning the potential for a vapor explosion in an advanced-fueled LMFBR. The test will be conducted in TREAT with unirradiated uranium-carbide fuel pins in the Mark-IICB integral flowing sodium loop. Our analysis addressed the ability of the experimental hardware to maintain its containment integrity during the reference accident postulated for the test. Based on a thermal-hydraulics analysis and assumptions for fuel-coolant interaction in the test section, a pressure pulse of 144 MPa maximum pressure and pulse width of 1.32 ms has been calculated as the reference accident. The response of the test loop to the pressure transient was obtained with the ICEPEL and STRAW codes. Modelling of the test section was completed with STRAW and the remainder of the loop was modelled by ICEPEL.

Zeuch, W.R.; A-Moneim, M.T.

1979-01-01T23:59:59.000Z

289

Hydrodynamic Modeling of Air Blast Propagation from the Humble Redwood Chemical High Explosive Detonations Using GEODYN  

Science Conference Proceedings (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

290

Flaring up: radio diagnostics of the kinematic, hydrodynamic and environmental properties of GRBs  

E-Print Network (OSTI)

The specific incidence of radio flares appears to be significantly larger than that of the prompt optical emission. This abundance, coupled with the reverse shock interpretation suggests that radio flares add a unique probe on the physics of GRB shocks. Motivated thus, we estimate the strength of the reverse shock expected for bursts in which multi-wavelength observations have allowed the physical parameters of the forward shock to be determined. We use all 6 bursts (980519, 990123, 990510, 991208, 991216, 000418) which are found to be adiabatic and thus predicted to have a strong reverse shock. We aim to constrain the hydrodynamic evolution of the reverse shock and the initial bulk Lorentz factor -- which we found to be between $10^{2}$ and $10^{3}$ and well above the lower limits derived from the requirement that gamma-ray bursts be optically thin to high-energy photons. In half of the cases we improve the description of the early afterglow lightcurves by adding a contribution from the reverse shock. Modelling of this early emission provides the opportunity to investigate the immediate surroundings of the burst. For 991216 and 991208, the expected $1/r^2$ density structure for a stellar wind is not compatible with the early afterglow lightcurves. Considering the radial range relevant to these GRBs, we discuss the conditions under which the inclusion of a wind termination shock may resolve the absence of a $1/r^2$ density profile.

A. M. Soderberg; E. Ramirez-Ruiz

2002-10-23T23:59:59.000Z

291

Evolution of M82-like starburst winds revisited: 3D radiative cooling hydrodynamical simulations  

E-Print Network (OSTI)

In this study we present three-dimensional radiative cooling hydrodynamical simulations of galactic winds generated particularly in M82-like starburst galaxies. We have considered intermittent winds induced by SNe explosions within super star clusters randomly distributed in the central region of the galaxy and were able to reproduce the observed M82 wind conditions with its complex morphological outflow structure. We have found that the environmental conditions in the disk in nearly recent past are crucial to determine whether the wind will develop a large scale rich filamentary structure, as in M82 wind, or not. Also, the numerical evolution of the SN ejecta have allowed us to obtain the abundance distribution over the first 3 kpc extension of the wind and we have found that the SNe explosions change significantly the metallicity only of the hot, low-density wind component. Moreover, we have found that the SN-driven wind transports to outside the disk large amounts of energy, momentum and gas, but the more ...

Melioli, C; Geraissate, F

2013-01-01T23:59:59.000Z

292

Hydrodynamic interactions and Brownian forces in colloidal suspensions: Coarse-graining over time and length-scales  

E-Print Network (OSTI)

We describe in detail how to implement a coarse-grained hybrid Molecular Dynamics and Stochastic Rotation Dynamics simulation technique that captures the combined effects of Brownian and hydrodynamic forces in colloidal suspensions. The importance of carefully tuning the simulation parameters to correctly resolve the multiple time and length-scales of this problem is emphasized. We systematically analyze how our coarse-graining scheme resolves dimensionless hydrodynamic numbers such as the Reynolds number, the Schmidt number, the Mach number, the Knudsen number, and the Peclet number. The many Brownian and hydrodynamic time-scales can be telescoped together to maximize computational efficiency while still correctly resolving the physically relevant physical processes. We also show how to control a number of numerical artifacts, such as finite size effects and solvent induced attractive depletion interactions. When all these considerations are properly taken into account, the measured colloidal velocity auto-correlation functions and related self diffusion and friction coefficients compare quantitatively with theoretical calculations. By contrast, these calculations demonstrate that, notwithstanding its seductive simplicity, the basic Langevin equation does a remarkably poor job of capturing the decay rate of the velocity auto-correlation function in the colloidal regime, strongly underestimating it at short times and strongly overestimating it at long times. Finally, we discuss in detail how to map the parameters of our method onto physical systems, and from this extract more general lessons that may be relevant for other coarse-graining schemes such as Lattice Boltzmann or Dissipative Particle Dynamics.

J. T. Padding; A. A. Louis

2006-03-14T23:59:59.000Z

293

DARHT : integration of shielding design and analysis with facility design /  

SciTech Connect

The design of the interior portions of the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility incorporated shielding and controls from the beginning of the installation of the Accelerators. The purpose of the design and analysis was to demonstrate the adequacy of shielding or to determine the need for additional shielding or controls. Two classes of events were considered: (1) routine operation defined as the annual production of 10,000 2000-ns pulses of electrons at a nominal energy of 20 MeV, some of which are converted to the x-ray imaging beam consisting of four nominal 60-ns pulses over the 2000-ns time frame, and (2) accident case defined as up to 100 2000-ns pulses of electrons accidentally impinging on some metallic surface, thereby producing x rays. Several locations for both classes of events were considered inside and outside of the accelerator hall buildings. The analysis method consisted of the definition of a source term for each case studied and the definition of a model of the shielding and equipment present between the source and the dose areas. A minimal model of the fixed existing or proposed shielding and equipment structures was used for a first approximation. If the resulting dose from the first approximation was below the design goal (1 rem/yr for routine operations, 5 rem for accident cases), then no further investigations were performed. If the result of the first approximation was above our design goals, the model was refined to include existing or proposed shielding and equipment. In some cases existing shielding and equipment were adequate to meet our goals and in some cases additional shielding was added or administrative controls were imposed to protect the workers. It is expected that the radiation shielding design, exclusion area designations, and access control features, will result in low doses to personnel at the DARHT Facility.

Boudrie, R. L. (Richard L.); Brown, T. H. (Thomas H.); Gilmore, W. E. (Walter E.); Downing, J. N. (James N.), Jr.; Hack, Alan; McClure, D. A. (Donald A.); Nelson, C. A. (Christine A.); Wadlinger, E. Alan; Zumbro, M. V. (Martha V.)

2002-01-01T23:59:59.000Z

294

High-brightness, high-spatial-resolution, 6.151 keV x-ray imaging of inertial confinement fusion capsule implosion and complex hydrodynamics experiments on Sandia's Z accelerator (invited)  

SciTech Connect

When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' 20 MA, 100 ns rise-time Z accelerator [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)], the terawatt-class, multikilojoule, 526.57 nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV, Mn-He{sub {alpha}} curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004)], is capable of providing a high quality x radiograph per Z shot for various high-energy-density physics experiments. Enhancements to this imaging system during 2005 have led to the capture of inertial confinement fusion capsule implosion and complex hydrodynamics images of significantly higher quality. The three main improvements, all leading effectively to enhanced image plane brightness, were bringing the source inside the Rowland circle to approximately double the collection solid angle, replacing direct exposure film with Fuji BAS-TR2025 image plate (read with a Fuji BAS-5000 scanner), and generating a 0.3-0.6 ns, {approx}200 J prepulse 2 ns before the 1.0 ns, {approx}1 kJ main pulse to more than double the 6.151 keV flux produced compared with a single 1 kJ pulse. It appears that the 20{+-}5 {mu}m imaging resolution is limited by the 25 {mu}m scanning resolution of the BAS-5000 unit, and to this end, a higher resolution scanner will replace it. ZBL is presently undergoing modifications to provide two temporally separated images ('two-frame') per Z shot for this system before the accelerator closes down in summer 2006 for the Z-refurbished (ZR) upgrade. In 2008, after ZR, it is anticipated that the high-energy petawatt (HEPW) addition to ZBL will be completed, possibly allowing high-energy 11.2224 and 15.7751 keV K{alpha}{sub 1} curved-crystal imaging to be performed. With an ongoing several-year project to develop a highly sensitive multiframe ultrafast digital x-ray camera (MUDXC), it is expected that two-frame HEPW 11 and 16 keV imaging and four-frame ZBL 6.151 keV curved-crystal imaging will be possible. MUDXC will be based on the technology of highly cooled silicon and germanium photodiode arrays and ultrafast, radiation-hardened integrated circuitry.

Bennett, G. R.; Sinars, D. B.; Wenger, D. F.; Cuneo, M. E.; Adams, R. G.; Barnard, W. J.; Beutler, D. E.; Burr, R. A.; Campbell, D. V.; Claus, L. D.; Foresi, J. S.; Johnson, D. W.; Keller, K. L.; Lackey, C.; Leifeste, G. T.; McPherson, L. A.; Mulville, T. D.; Neely, K. A.; Rambo, P. K.; Rovang, D. C. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1106 (United States)] (and others)

2006-10-15T23:59:59.000Z

295

Hydrodynamic Simulation of a nano-flare heated multi-strand solar atmospheric loop  

E-Print Network (OSTI)

There is a growing body of evidence that the plasma loops seen with current instrumentation (SOHO, TRACE and Hinode) may consist of many sub-resolution elements or strands. Thus, the overall plasma evolution we observe in these features could be the cumulative result of numerous individual strands undergoing sporadic heating. This paper presents a short (10^9 cm ~ 10 Mm) ``global loop'' as 125 individual strands where each strand is modelled independently by a one-dimensional hydrodynamic simulation. The energy release mechanism across the strands consists of localised, discrete heating events (nano-flares). The strands are ``coupled'' together through the frequency distribution of the total energy input to the loop which follows a power law distribution with index alpha. The location and lifetime of each energy event occurring is random. Although a typical strand can go through a series of well-defined heating/cooling cycles, when the strands are combined, the overall quasi-static emission measure weighted thermal profile for the global loop reproduces a hot apex/cool base structure. Localised cool plasma blobs are seen to travel along individual strands which could cause the loop to `disappear' from coronal emission and appear in transition or chromospheric ones. As alpha increases (from 0 to 2.29 to 3.29), more weight is given to the smallest heating episodes. Consequently, the overall global loop apex temperature increases while the variation of the temperature around that value decreases. Any further increase in alpha saturates the loop apex temperature variations at the current simulation resolution. The effect of increasing the number of strands and the loop length as well as the implications of these results upon possible future observing campaigns for TRACE and Hinode are discussed.

Aveek Sarkar; Robert W Walsh

2008-04-18T23:59:59.000Z

296

Hydrodynamic Models of Type I X-Ray Bursts: Metallicity Effects  

E-Print Network (OSTI)

Type I X-ray bursts are thermonuclear stellar explosions driven by charged-particle reactions. In the regime for combined H/He-ignition, the main nuclear flow is dominated by the rp-process (rapid proton-captures and beta+ decays), the 3 alpha-reaction, and the alpha-p-process (a suite of (alpha,p) and (p,gamma) reactions). The main flow is expected to proceed away from the valley of stability, eventually reaching the proton drip-line beyond A = 38. Detailed analysis of the relevant reactions along the main path has only been scarcely addressed, mainly in the context of parameterized one-zone models. In this paper, we present a detailed study of the nucleosynthesis and nuclear processes powering type I X-ray bursts. The reported 11 bursts have been computed by means of a spherically symmetric (1D), Lagrangian, hydrodynamic code, linked to a nuclear reaction network that contains 325 isotopes (from 1H to 107Te), and 1392 nuclear processes. These evolutionary sequences, followed from the onset of accretion up to the explosion and expansion stages, have been performed for 2 different metallicities to explore the dependence between the extension of the main nuclear flow and the initial metal content. We carefully analyze the dominant reactions and the products of nucleosynthesis, together with the the physical parameters that determine the light curve (including recurrence times, ratios between persistent and burst luminosities, or the extent of the envelope expansion). Results are in qualitative agreement with the observed properties of some well-studied bursting sources. Leakage from the predicted SbSnTe-cycle cannot be discarded in some of our models. Production of 12C (and implications for the mechanism that powers superbursts), light p-nuclei, and the amount of H left over after the bursting episodes will also be discussed.

Jordi Jose; Fermin Moreno; Anuj Parikh; Christian Iliadis

2010-05-26T23:59:59.000Z

297

On the Accuracy of Finite-Volume Schemes for Fluctuating Hydrodynamics  

E-Print Network (OSTI)

This paper describes the development and analysis of finite-volume methods for the Landau-Lifshitz Navier-Stokes (LLNS) equations and related stochastic partial differential equations in fluid dynamics. The LLNS equations incorporate thermal fluctuations into macroscopic hydrodynamics by the addition of white-noise fluxes whose magnitudes are set by a fluctuation-dissipation relation. Originally derived for equilibrium fluctuations, the LLNS equations have also been shown to be accurate for non-equilibrium systems. Previous studies of numerical methods for the LLNS equations focused primarily on measuring variances and correlations computed at equilibrium and for selected non-equilibrium flows. In this paper, we introduce a more systematic approach based on studying discrete equilibrium structure factors for a broad class of explicit linear finite-volume schemes. This new approach provides a better characterization of the accuracy of a spatio-temporal discretization as a function of wavenumber and frequency, allowing us to distinguish between behavior at long wavelengths, where accuracy is a prime concern, and short wavelengths, where stability concerns are of greater importance. We use this analysis to develop a specialized third-order Runge Kutta scheme that minimizes the temporal integration error in the discrete structure factor at long wavelengths for the one-dimensional linearized LLNS equations. Together with a novel method for discretizing the stochastic stress tensor in dimension larger than one, our improved temporal integrator yields a scheme for the three-dimensional equations that satisfies a discrete fluctuation-dissipation balance for small time steps and is also sufficiently accurate even for time steps close to the stability limit.

A. Donev; E. Vanden-Eijnden; A. L. Garcia; J. B. Bell

2009-06-12T23:59:59.000Z

298

Evaluation of Collector Well Configurations to Model Hydrodynamics in Riverbank Filtration and Groundwater Remediation  

E-Print Network (OSTI)

Collector well designs are necessary to maximize groundwater uptake and riverbank filtration without negatively impacting an aquifer. Unfortunately, there is a lack of information and research regarding the implementation of collector well design parameters. In the past, collector well installation was too costly, but recent advances in well technology have made collector wells more cost effective. This research will contribute a set of guidelines to optimize riverbank filtration and groundwater remediation. This study models the hydrodynamics surrounding collector well configurations in riverbank filtration and groundwater remediation. Visual Modflow® was utilized to run a variety of numerical models to test four areas: flux along the laterals of a collector well, collector well interactions with a river, collector well yield, and collector well remediation capability. The two design parameters investigated were lateral length (25 m, 50 m, and 100 m) and number of laterals (3 and 4). The lateral flux tests confirm flux increases towards the terminal end of each lateral and pumping rate is the controlling factor in flux amount obtained along the laterals. The analysis of the flux-river interaction shows the main factor in determining flux amount is the initial river geometry, followed by the pumping rate, regional background flow, and collector well design, respectively. The models suggest that the 4-lateral collector well design is more effective than the 3-lateral design and in addition, 100 meter length laterals provide the highest amount of yield with the least amount of drawdown. The remediation tests investigate the application of vertical well equations to evaluate collector well designs in two areas: minimum pumping rate to capture line source of particles and first arrival time of particles. The remediation models show 100 meter length laterals provide both the lowest pumping rate and the highest residence time with the surrounding aquifer for maximum remediation. Ultimately, these models provide basic design guidelines and explain which designs are most effective, depending on the collector well purpose.

De Leon, Tiffany Lucinda

2010-08-01T23:59:59.000Z

299

FORCE2: A state-of-the-art two-phase code for hydrodynamic calculations  

SciTech Connect

A three-dimensional computer code for two-phase flow named FORCE2 has been developed by Babcock and Wilcox (B & W) in close collaboration with Argonne National Laboratory (ANL). FORCE2 is capable of both transient as well as steady-state simulations. This Cartesian coordinates computer program is a finite control volume, industrial grade and quality embodiment of the pilot-scale FLUFIX/MOD2 code and contains features such as three-dimensional blockages, volume and surface porosities to account for various obstructions in the flow field, and distributed resistance modeling to account for pressure drops caused by baffles, distributor plates and large tube banks. Recently computed results demonstrated the significance of and necessity for three-dimensional models of hydrodynamics and erosion. This paper describes the process whereby ANL`s pilot-scale FLUFIX/MOD2 models and numerics were implemented into FORCE2. A description of the quality control to assess the accuracy of the new code and the validation using some of the measured data from Illinois Institute of Technology (UT) and the University of Illinois at Urbana-Champaign (UIUC) are given. It is envisioned that one day, FORCE2 with additional modules such as radiation heat transfer, combustion kinetics and multi-solids together with user-friendly pre- and post-processor software and tailored for massively parallel multiprocessor shared memory computational platforms will be used by industry and researchers to assist in reducing and/or eliminating the environmental and economic barriers which limit full consideration of coal, shale and biomass as energy sources, to retain energy security, and to remediate waste and ecological problems.

Ding, Jianmin; Lyczkowski, R.W. [Argonne National Lab., IL (United States); Burge, S.W. [Babcock and Wilcox Co., Alliance, OH (United States). Research Center

1993-02-01T23:59:59.000Z

300

FORCE2: A state-of-the-art two-phase code for hydrodynamic calculations  

SciTech Connect

A three-dimensional computer code for two-phase flow named FORCE2 has been developed by Babcock and Wilcox (B W) in close collaboration with Argonne National Laboratory (ANL). FORCE2 is capable of both transient as well as steady-state simulations. This Cartesian coordinates computer program is a finite control volume, industrial grade and quality embodiment of the pilot-scale FLUFIX/MOD2 code and contains features such as three-dimensional blockages, volume and surface porosities to account for various obstructions in the flow field, and distributed resistance modeling to account for pressure drops caused by baffles, distributor plates and large tube banks. Recently computed results demonstrated the significance of and necessity for three-dimensional models of hydrodynamics and erosion. This paper describes the process whereby ANL's pilot-scale FLUFIX/MOD2 models and numerics were implemented into FORCE2. A description of the quality control to assess the accuracy of the new code and the validation using some of the measured data from Illinois Institute of Technology (UT) and the University of Illinois at Urbana-Champaign (UIUC) are given. It is envisioned that one day, FORCE2 with additional modules such as radiation heat transfer, combustion kinetics and multi-solids together with user-friendly pre- and post-processor software and tailored for massively parallel multiprocessor shared memory computational platforms will be used by industry and researchers to assist in reducing and/or eliminating the environmental and economic barriers which limit full consideration of coal, shale and biomass as energy sources, to retain energy security, and to remediate waste and ecological problems.

Ding, Jianmin; Lyczkowski, R.W. (Argonne National Lab., IL (United States)); Burge, S.W. (Babcock and Wilcox Co., Alliance, OH (United States). Research Center)

1993-02-01T23:59:59.000Z

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301

Radiation-Hydrodynamic Simulations of Massive Star Formation with Protostellar Outflows  

Science Conference Proceedings (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

302

Smoothed particle hydrodynamics Non-Newtonian model for ice-sheet and ice-shelf dynamics  

SciTech Connect

Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) non-Newtonian model for coupled ice sheet and ice shelf dynamics. SPH, a fully Lagrangian particle method, is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface ?ows, large material deformation, and material fragmentation. In this paper, SPH is used to study 3D ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios, similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is veri?ed by simulating Poiseuille ?ow, plane shear ?ow with free surface and the propagation of a blob of ice along a horizontal surface. In the laboratory experiment, the ice was represented with a viscous Newtonian ?uid. In the present work, however, the ice is modeled as both viscous Newtonian ?uid and non-Newtonian ?uid, such that the e?ect of non-Newtonian rheology on the dynamics of grounding line was examined. The non-Newtonian constitutive relation is prescribed to be Glen’s law for the creep of polycrystalline ice. A V-shaped bedrock ramp is further introduced to model the real geometry of bedrock slope.

Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

2013-06-01T23:59:59.000Z

303

A Smoothed Particle Hydrodynamics Model for Ice Sheet and Ice Shelf Dynamics  

SciTech Connect

Mathematical modeling of ice sheets is complicated by the non-linearity of the governing equations and boundary conditions. Standard grid-based methods require complex front tracking techniques and have limited capability to handle large material deformations and abrupt changes in bottom topography. As a consequence, numerical methods are usually restricted to shallow ice sheet and ice shelf approximations. We propose a new smoothed particle hydrodynamics (SPH) model for coupled ice sheet and ice shelf dynamics. SPH is a fully Lagrangian particle method. It is highly scalable and its Lagrangian nature and meshless discretization are well suited to the simulation of free surface flows, large material deformation, and material fragmentation. In this paper SPH is used to study ice sheet/ice shelf behavior, and the dynamics of the grounding line. The steady state position of the grounding line obtained from the SPH simulations is in good agreement with laboratory observations for a wide range of simulated bedrock slopes, and density ratios similar to those of ice and sea water. The numerical accuracy of the SPH algorithm is further verified by simulating the plane shear flow of two immiscible fluids and the propagation of a highly viscous blob of fluid along a horizontal surface. In the experiment, the ice was represented with a viscous newtonian fluid. For consistency, in the described SPH model the ice is also modeled as a viscous newtonian fluid. Typically, ice sheets are modeled as a non-Newtonian fluid, accounting for the changes in the mechanical properties of ice. Implementation of a non-Newtonian rheology in the SPH model is the subject of our ongoing research.

Pan, Wenxiao; Tartakovsky, Alexandre M.; Monaghan, Joseph J.

2012-02-08T23:59:59.000Z

304

A TWO-MOMENT RADIATION HYDRODYNAMICS MODULE IN ATHENA USING A TIME-EXPLICIT GODUNOV METHOD  

SciTech Connect

We describe a module for the Athena code that solves the gray equations of radiation hydrodynamics (RHD), based on the first two moments of the radiative transfer equation. We use a combination of explicit Godunov methods to advance the gas and radiation variables including the non-stiff source terms, and a local implicit method to integrate the stiff source terms. We adopt the M{sub 1} closure relation and include all leading source terms to O({beta}{tau}). We employ the reduced speed of light approximation (RSLA) with subcycling of the radiation variables in order to reduce computational costs. Our code is dimensionally unsplit in one, two, and three space dimensions and is parallelized using MPI. The streaming and diffusion limits are well described by the M{sub 1} closure model, and our implementation shows excellent behavior for a problem with a concentrated radiation source containing both regimes simultaneously. Our operator-split method is ideally suited for problems with a slowly varying radiation field and dynamical gas flows, in which the effect of the RSLA is minimal. We present an analysis of the dispersion relation of RHD linear waves highlighting the conditions of applicability for the RSLA. To demonstrate the accuracy of our method, we utilize a suite of radiation and RHD tests covering a broad range of regimes, including RHD waves, shocks, and equilibria, which show second-order convergence in most cases. As an application, we investigate radiation-driven ejection of a dusty, optically thick shell in the ISM. Finally, we compare the timing of our method with other well-known iterative schemes for the RHD equations. Our code implementation, Hyperion, is suitable for a wide variety of astrophysical applications and will be made freely available on the Web.

Skinner, M. Aaron; Ostriker, Eve C., E-mail: askinner@astro.umd.edu, E-mail: eco@astro.princeton.edu [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

2013-06-01T23:59:59.000Z

305

Three-fluid plasmas in star formation I. Magneto-hydrodynamic equations  

E-Print Network (OSTI)

Interstellar magnetic fields influence all stages of the process of star formation, from the collapse of molecular cloud cores to the formation of protostellar jets. This requires us to have a full understanding of the physical properties of magnetized plasmas of different degrees of ionization for a wide range of densities and temperatures. We derive general equations governing the magneto-hydrodynamic evolution of a three-fluid medium of arbitrary ionization, also including the possibility of charged dust grains as the main charge carriers. In a companion paper (Pinto & Galli 2007), we complement this analysis computing accurate expressions of the collisional coupling coefficients. Over spatial and temporal scales larger than the so-called large-scale plasma limit and the collision-dominated plasma limit, and for non-relativistic fluid speeds, we obtain an advection-diffusion for the magnetic field. We derive the general expressions for the resistivities, the diffusion time scales and the heating rates in a three-fluid medium and we use them to estimate the evolution of the magnetic field in molecular clouds and protostellar jets. Collisions between charged particles significantly increase the value of the Ohmic resistivity during the process of cloud collapse, affecting in particular the decoupling of matter and magnetic field and enhancing the rate of energy dissipation. The Hall resistivity can take larger values than previously found when the negative charge is mostly carried by dust grains. In weakly-or mildy-ionized protostellar jets, ambipolar diffusion is found to occur on a time scale comparable to the dynamical time scale, limiting the validity of steady-state and nondissipative models to study the jet's structure.

Cecilia Pinto; Daniele Galli; Francesca Bacciotti

2008-04-17T23:59:59.000Z

306

Modeling and analysis of transient vehicle underhood thermo- hydrodynamic events using computational fluid dynamics and high performance computing.  

DOE Green Energy (OSTI)

This work has explored the preliminary design of a Computational Fluid Dynamics (CFD) tool for the analysis of transient vehicle underhood thermo-hydrodynamic events using high performance computing platforms. The goal of this tool will be to extend the capabilities of an existing established CFD code, STAR-CD, allowing the car manufacturers to analyze the impact of transient operational events on the underhood thermal management by exploiting the computational efficiency of modern high performance computing systems. In particular, the project has focused on the CFD modeling of the radiator behavior during a specified transient. The 3-D radiator calculations were performed using STAR-CD, which can perform both steady-state and transient calculations, on the cluster computer available at ANL in the Nuclear Engineering Division. Specified transient boundary conditions, based on experimental data provided by Adapco and DaimlerChrysler were used. The possibility of using STAR-CD in a transient mode for the entire period of time analyzed has been compared with other strategies which involve the use of STAR-CD in a steady-state mode at specified time intervals, while transient heat transfer calculations would be performed for the rest of the time. The results of these calculations have been compared with the experimental data provided by Adapco/DaimlerChrysler and recommendations for future development of an optimal strategy for the CFD modeling of transient thermo-hydrodynamic events have been made. The results of this work open the way for the development of a CFD tool for the transient analysis of underhood thermo-hydrodynamic events, which will allow the integrated transient thermal analysis of the entire cooling system, including both the engine block and the radiator, on high performance computing systems.

Tentner, A.; Froehle, P.; Wang, C.; Nuclear Engineering Division

2004-01-01T23:59:59.000Z

307

Modeling and analysis of transient vehicle underhood thermo - hydrodynamic events using computational fluid dynamics and high performance computing.  

DOE Green Energy (OSTI)

This work has explored the preliminary design of a Computational Fluid Dynamics (CFD) tool for the analysis of transient vehicle underhood thermo-hydrodynamic events using high performance computing platforms. The goal of this tool will be to extend the capabilities of an existing established CFD code, STAR-CD, allowing the car manufacturers to analyze the impact of transient operational events on the underhood thermal management by exploiting the computational efficiency of modern high performance computing systems. In particular, the project has focused on the CFD modeling of the radiator behavior during a specified transient. The 3-D radiator calculations were performed using STAR-CD, which can perform both steady-state and transient calculations, on the cluster computer available at ANL in the Nuclear Engineering Division. Specified transient boundary conditions, based on experimental data provided by Adapco and DaimlerChrysler were used. The possibility of using STAR-CD in a transient mode for the entire period of time analyzed has been compared with other strategies which involve the use of STAR-CD in a steady-state mode at specified time intervals, while transient heat transfer calculations would be performed for the rest of the time. The results of these calculations have been compared with the experimental data provided by Adapco/DaimlerChrysler and recommendations for future development of an optimal strategy for the CFD modeling of transient thermo-hydrodynamic events have been made. The results of this work open the way for the development of a CFD tool for the transient analysis of underhood thermo-hydrodynamic events, which will allow the integrated transient thermal analysis of the entire cooling system, including both the engine block and the radiator, on high performance computing systems.

Froehle, P.; Tentner, A.; Wang, C.

2003-09-05T23:59:59.000Z

308

Protoneutron star evolution and the neutrino-driven wind in general relativistic neutrino radiation hydrodynamics simulations  

SciTech Connect

Massive stars end their lives in explosions with kinetic energies on the order of 10{sup 51} erg. Immediately after the explosion has been launched, a region of low density and high entropy forms behind the ejecta, which is continuously subject to neutrino heating. The neutrinos emitted from the remnant at the center, the protoneutron star (PNS), heat the material above the PNS surface. This heat is partly converted into kinetic energy, and the material accelerates to an outflow that is known as the neutrino-driven wind. For the first time we simulate the collapse, bounce, explosion, and the neutrino-driven wind phases consistently over more than 20 s. Our numerical model is based on spherically symmetric general relativistic radiation hydrodynamics using spectral three-flavor Boltzmann neutrino transport. In simulations where no explosions are obtained naturally, we model neutrino-driven explosions for low- and intermediate-mass Fe-core progenitor stars by enhancing the charged current reaction rates. In the case of a special progenitor star, the 8.8 M{circle_dot} O-Ne-Mg-core, the explosion in spherical symmetry was obtained without enhanced opacities. The post-explosion evolution is in qualitative agreement with static steady-state and parametrized dynamic models of the neutrino-driven wind. On the other hand, we generally find lower neutrino luminosities and mean neutrino energies, as well as a different evolutionary behavior of the neutrino luminosities and mean neutrino energies. The neutrino-driven wind is proton-rich for more than 10 s and the contraction of the PNS differs from the assumptions made for the conditions at the inner boundary in previous neutrino-driven wind studies. Despite the moderately high entropies of about 100 k{sub B}/baryon and the fast expansion timescales, the conditions found in our models are unlikely to favor r-process nucleosynthesis. The simulations are carried out until the neutrino-driven wind settles down to a quasi-stationary state. About 5 s after the bounce, the peak temperature inside the PNS already starts to decrease because of the continued deleptonization. This moment determines the beginning of a cooling phase dominated by the emission of neutrinos. We discuss the physical conditions of the quasi-static PNS evolution and take the effects of deleptonization and mass accretion from early fallback into account.

Fischer, T. [University of Basel; Mezzacappa, Anthony [ORNL; Thielemann, F.-K. [University of Basel; Liebendoerfer, M. [University of Basel; Whitehouse, S. [University of Basel

2010-01-01T23:59:59.000Z

309

Features of two-pion Bose-Einstein correlations based on event-by-event analysis in smoothed particle hydrodynamics  

E-Print Network (OSTI)

We examine the space-time structure of the particle-emitting sources with fluctuating initial conditions in smoothed particle hydrodynamics. The two-pion correlation functions of single events for the sources exhibit event-by-event fluctuations. The large event-by-event fluctuations and wide distributions of the error-inverse-weighted fluctuations between the HBT correlation functions of single and mixed events are important features for the sources with event-by-event fluctuating initial conditions. The root-mean-square of the weighted fluctuations is a signal to detect the inhomogeneity of the systems produced in high energy heavy ion collisions.

Ren, Yan-Yu; Liu, Jian-Li

2008-01-01T23:59:59.000Z

310

Assessment of Tidal Energy Removal Impacts on Physical Systems: Development of MHK Module and Analysis of Effects on Hydrodynamics  

SciTech Connect

In this report we describe (1) the development, test, and validation of the marine hydrokinetic energy scheme in a three-dimensional coastal ocean model (FVCOM); and (2) the sensitivity analysis of effects of marine hydrokinetic energy configurations on power extraction and volume flux in a coastal bay. Submittal of this report completes the work on Task 2.1.2, Effects of Physical Systems, Subtask 2.1.2.1, Hydrodynamics and Subtask 2.1.2.3, Screening Analysis, for fiscal year 2011 of the Environmental Effects of Marine and Hydrokinetic Energy project.

Yang, Zhaoqing; Wang, Taiping

2011-09-01T23:59:59.000Z

311

A Radiation-Hydrodynamics Code Comparison for Laser-Produced Plasmas: FLASH versus HYDRA and the Results of Validation Experiments  

E-Print Network (OSTI)

The potential for laser-produced plasmas to yield fundamental insights into high energy density physics (HEDP) and deliver other useful applications can sometimes be frustrated by uncertainties in modeling the properties and expansion of these plasmas using radiation-hydrodynamics codes. In an effort to overcome this and to corroborate the accuracy of the HEDP capabilities recently added to the publicly available FLASH radiation-hydrodynamics code, we present detailed comparisons of FLASH results to new and previously published results from the HYDRA code used extensively at Lawrence Livermore National Laboratory. We focus on two very different problems of interest: (1) an Aluminum slab irradiated by 15.3 and 76.7 mJ of "pre-pulse" laser energy and (2) a mm-long triangular groove cut in an Aluminum target irradiated by a rectangular laser beam. Because this latter problem bears a resemblance to astrophysical jets, Grava et al., Phys. Rev. E, 78, (2008) performed this experiment and compared detailed x-ray int...

Orban, Chris; Chawla, Sugreev; Wilks, Scott C; Lamb, Donald Q

2013-01-01T23:59:59.000Z

312

Hydrodynamics and energy consumption studies in a three-phase liquid circulating three-phase fluid bed contactor  

SciTech Connect

The hydrodynamics and energy consumption have been studied in a cold flow, bubbling and turbulent, pressurized gas-liquid-solid three-phase fluidized bed (0.15 m ID x 1 m height) with concurrent gas-liquid up flow is proposed with the intention of increasing the gas hold up. The hydrodynamic behaviour is described and characterised by some specific gas and liquid velocities. Particles are easily fluidized and can be uniformly distributed over the whole height of the column. The effect of parameters like liquid flow rate, gas flow rate, particle loading, particle size, and solid density on gas hold up and effect of gas flow rate, solid density and particle size on solid hold up, energy consumption and minimum fluidization velocity has been studied. At the elevated pressures a superior method for better prediction of minimum fluidization velocity and terminal settling velocities has been adopted. The results have been interpreted with Bernoulli's theorem and Richardson-Zaki equation. Based on the assumption of the gas and liquid as a pretend fluid, a simplification has been made to predict the particle terminal settling velocities. The Richardson-Zaki parameter n' was compared with Renzo's results. A correlation has been proposed with the experimental results for the three-phase fluidization. (author)

Rusumdar, Ahmad J [Thirumalai Engineering College, Kancheepuram, Tamil Nadu (India); Dept. of Modelling, Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig (Germany); Abuthalib, A. [Dept. of Modelling, Leibniz Institute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig (Germany); Mohan, Vaka Murali; Srinivasa Kumar, C. [Dept. of CSE, New Netaji Institute of Technology, Toopranpet, Nalgonda 508 252, AP (India); Sujatha, V.; Rajendra Prasad, P. [Dept. of Chemical Engineering, Andhra University, College of Engineering, Visakhapatnam 530 003, AP (India)

2009-07-15T23:59:59.000Z

313

Elliptic flow ($v_2$) in pp collisions at energies available at the CERN Large Hadron Collider: A hydrodynamical approach  

E-Print Network (OSTI)

At Large Hadron Collider energy, the expected large multiplicities suggests the presence of collective behavior even in pp collisions. A hydrodynamical approach has been applied to estimate the expected elliptic flow measured by the azimuthal asymmetry parameter $v_2$, in pp collisions at $\\surd$s = 14 TeV. $v_2$ of $\\pi^-$ is found to be strongly dependent on the parton density profile inside a proton [e.g., surface diffuseness parameter ($\\xi$)]. For $\\xi$ = 0.105, $v_2$ is found to be positive while at $\\xi$ = 0.25, $v_2$ is close to zero and approaches negative values at large $p_t$. The impact parameter dependence of $v_2$ has also been studied.

S. K. Prasad; Victor Roy; S. Chattopadhyay; A. K. Chaudhuri

2009-10-26T23:59:59.000Z

314

High-Temperature Processing of Solids Through Solar Nebular Bow Shocks: 3D Radiation Hydrodynamics Simulations with Particles  

E-Print Network (OSTI)

A fundamental, unsolved problem in Solar System formation is explaining the melting and crystallization of chondrules found in chondritic meteorites. Theoretical models of chondrule melting in nebular shocks has been shown to be consistent with many aspects of thermal histories inferred for chondrules from laboratory experiments; but, the mechanism driving these shocks is unknown. Planetesimals and planetary embryos on eccentric orbits can produce bow shocks as they move supersonically through the disk gas, and are one possible source of chondrule-melting shocks. We investigate chondrule formation in bow shocks around planetoids through 3D radiation hydrodynamics simulations. A new radiation transport algorithm that combines elements of flux-limited diffusion and Monte Carlo methods is used to capture the complexity of radiative transport around bow shocks. An equation of state that includes the rotational, vibrational, and dissociation modes of H$_2$ is also used. Solids are followed directly in the simulati...

Boley, A C; Desch, S J

2013-01-01T23:59:59.000Z

315

A Parallel Implementation of a Smoothed Particle Hydrodynamics Method on Graphics Hardware Using the Compute Unified Device Architecture  

Science Conference Proceedings (OSTI)

The smoothed particle hydrodynamics (SPH), which is a class of meshfree particle methods (MPMs), has a wide range of applications from micro-scale to macro-scale as well as from discrete systems to continuum systems. Graphics hardware, originally designed for computer graphics, now provide unprecedented computational power for scientific computation. Particle system needs a huge amount of computations in physical simulation. In this paper, an efficient parallel implementation of a SPH method on graphics hardware using the Compute Unified Device Architecture is developed for fluid simulation. Comparing to the corresponding CPU implementation, our experimental results show that the new approach allows significant speedups of fluid simulation through handling huge amount of computations in parallel on graphics hardware.

Wong Unhong; Wong Honcheng; Tang Zesheng [NAOC-MUST Collaborative Research Laboratory for Lunar and Planetary Exploration, Faculty of Information Technology, Macau University of Science and Technology, Macao (China)

2010-05-21T23:59:59.000Z

316

Effect of design parameter variations on hybrid (combination hydrostatic and hydrodynamic) bearings for use in high speed turbomachinery  

E-Print Network (OSTI)

Hybrid (combination hydrostatic and hydrodynamic) bearings have been proposed for use as a support element in cryogenic high speed turbomachinery for primary and auxiliary space power applications because of their long lifetime, low friction and wear, and ability to use low viscosity fluids. However, very little work has been done in determining the rotordynamic performance of hybrid journal bearings. This thesis presents theoretical and experimental results for radial-injection, orifice-compensated, annulus-fed hybrid water journal bearings which show the effects on bearing performance of changing the following design parameters: radial clearance, concentric recess pressure ratio, recess-to-land area ratio, and recess depth geometry. Experimental test results are used to evaluate predictions from the analytical hybrid bearing computer model developed by San Andres (1990).

Mosher, Phillip Andrew

1993-01-01T23:59:59.000Z

317

Investigation of hydrodynamics of a dual fluidized bed biomass steam gasifier using a cold model: The effect of fluidising agent on gasification performance  

E-Print Network (OSTI)

Investigation of hydrodynamics of a dual fluidized bed biomass steam gasifier using a cold model) biomass steam gasifiers are able to produce gas with low tar and high hydrogen contents and have shown a promising potential for converting the biomass to hydrogen-rich syngas. The DFB gasifier system

Hickman, Mark

318

A Coupled Hydrodynamic–Bottom Boundary Layer Model of Storm and Tidal Flow in the Middle Atlantic Bight of North America  

Science Conference Proceedings (OSTI)

The effects of increased friction and tides on circulation in the Middle Atlantic Bight (MAB) during the SWADE storm of 25–28 October 1990 have been investigated using a three-dimensional hydrodynamic model coupled to a bottom boundary layer ...

Timothy R. Keen; Scott M. Glenn

1995-03-01T23:59:59.000Z

319

Tuning the DARHT Axis-II linear induction accelerator focusing  

SciTech Connect

Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an accelerator cell to replace a failed solenoid in March of 2012. We took advantage of this opportunity to improve the design of the focusing tune with better models of the remaining partially failed solenoids, better estimates of beam initial conditions, and better values for pulsed-power voltages. As with all previous tunes for Axis-II, this one incorporates measures to mitigate beam-breakup (BBU) instability, image displacement instability (IDI), corkscrew (sweep), and emittance growth. Section II covers the general approach to of design of focusing solenoid tunes for the DARHT Axis-2 LIA. Section III explains the specific requirements and simulations needed to design the tune for the injector, which includes the thermionic electron source, diode, and six induction cells. Section IV explains the requirements and simulations for tuning the main accelerator, which consists of 68 induction cells. Finally, Section V explores sensitivity of the tune to deviations of parameters from nominal, random variations, and uncertainties in values. Four appendices list solenoid settings for this new tune, discuss comparisons of different simulation codes, show halo formation in mismatched beams, and present a brief discussion of the beam envelope equation, which is the heart of the method used to design LIA solenoid tunes.

Ekdahl, Carl A. [Los Alamos National Laboratory

2012-04-24T23:59:59.000Z

320

Triangular flow in event-by-event ideal hydrodynamics in Au+Au collisions at {radical}(s{sub NN})=200A GeV  

Science Conference Proceedings (OSTI)

The first calculation of triangular flow v{sub 3} in Au+Au collisions at {radical}(s{sub NN})=200A GeV from an event-by-event (3+1)d transport+hydrodynamics hybrid approach is presented. As a response to the initial triangularity {epsilon}{sub 3} of the collision zone, v{sub 3} is computed in a similar way to the standard event-plane analysis for elliptic flow v{sub 2}. It is found that the triangular flow exhibits weak centrality dependence and is roughly equal to elliptic flow in most central collisions. We also explore the transverse momentum and rapidity dependence of v{sub 2} and v{sub 3} for charged particles as well as identified particles. We conclude that an event-by-event treatment of the ideal hydrodynamic evolution starting with realistic initial conditions generates the main features expected for triangular flow.

Petersen, Hannah; Qin Guangyou; Bass, Steffen A.; Mueller, Berndt [Department of Physics, Duke University, Durham, North Carolina 27708-0305 (United States)

2010-10-15T23:59:59.000Z

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321

The mass loss process in dwarf galaxies from 3D hydrodynamical simulations: the role of dark matter and starbursts  

E-Print Network (OSTI)

Theoretical $\\Lambda$CDM cosmological models predict a much larger number of low mass dark matter haloes than has been observed in the Local Group of galaxies. One possible explanation is the increased difficulty of detecting these haloes if most of the visible matter is lost at early evolutionary phases through galactic winds. In this work we study the current models of triggering galactic winds in dwarf spheroidal galaxies (dSph) from supernovae, and study, based on 3D hydrodynamic numerical simulations, the correlation of the mass loss rates and important physical parameters as the dark matter halo mass and its radial profile, and the star formation rate. We find that the existence of winds is ubiquitous, independent on the gravitational potential. Our simulations revealed that the Rayleigh-Taylor Instability (RTI) may play a major role on pushing matter out of these systems, even for very massive haloes. The instability is responsible for 5 - 40% of the mass loss during the early evolution of the galaxy, ...

Ruiz, Luciana O; Lanfranchi, Gustavo A; Caproni, Anderson

2012-01-01T23:59:59.000Z

322

Quantum hydrodynamics approach to the formation of waves in polarized two-dimensional systems of charged and neutral particles  

Science Conference Proceedings (OSTI)

In this paper, we explicate a method of quantum hydrodynamics (QHD) for the study of the quantum evolution of a system of polarized particles. Although we focused primarily on the two-dimensional (2D) physical systems, the method is valid for three-dimensional (3D) and one-dimensional (1D) systems too. The presented method is based upon the Schroedinger equation. Fundamental QHD equations for charged and neutral particles were derived from the many-particle microscopic Schroedinger equation. The fact that particles possess the electric dipole moment (EDM) was taken into account. The explicated QHD approach was used to study dispersion characteristics of various physical systems. We analyzed dispersion of waves in a two-dimensional ion and hole gas placed into an external electric field, which is orthogonal to the gas plane. Elementary excitations in a system of neutral polarized particles were studied for 1D, 2D, and 3D cases. The polarization dynamics in systems of both neutral and charged particles is shown to cause formation of a new type of waves as well as changes in the dispersion characteristics of already known waves. We also analyzed wave dispersion in 2D exciton systems, in 2D electron-ion plasma, and in 2D electron-hole plasma. Generation of waves in 3D-system neutral particles with EDM by means of the beam of electrons and neutral polarized particles is investigated.

Andreev, P. A.; Kuzmenkov, L. S.; Trukhanova, M. I. [Department of General Physics, Physics Faculty, Moscow State University, Moscow (Russian Federation); Dpartment of Theoretical Physics, Physics Faculty, Moscow State University, Moscow (Russian Federation)

2011-12-15T23:59:59.000Z

323

Development of a sub-scale dynamics model for pressure relaxation of multi-material cells in Lagrangian hydrodynamics  

SciTech Connect

We have extended the Sub-Scale Dynamics (SSD) closure model for multi-fluid computational cells. Volume exchange between two materials is based on the interface area and a notional interface translation velocity, which is derived from a linearized Riemann solution. We have extended the model to cells with any number of materials, computing pressure-difference-driven volume and energy exchange as the algebraic sum of pairwise interactions. In multiple dimensions, we rely on interface reconstruction to provide interface areas and orientations, and centroids of material polygons. In order to prevent unphysically large or unmanageably small material volumes, we have used a flux-corrected transport (FCT) approach to limit the pressure-driven part of the volume exchange. We describe the implementation of this model in two dimensions in the FLAG hydrodynamics code. We also report on Lagrangian test calculations, comparing them with others made using a mixed-zone closure model due to Tipton, and with corresponding calculations made with only single-material cells. We find that in some cases, the SSD model more accurately predicts the state of material in mixed cells. By comparing the algebraic forms of both models, we identify similar dependencies on state and dynamical variables, and propose explanations for the apparent higher fidelity of the SSD model.

Harrison, Alan K [Los Alamos National Laboratory; Shashkov, Mikhail J [Los Alamos National Laboratory; Fung, Jimmy [Los Alamos National Laboratory; Canfield, Thomas R [Los Alamos National Laboratory; Kamm, James R [SNLA

2010-10-14T23:59:59.000Z

324

REVIEW OF EXPERIMENTAL CAPABILITIES AND HYDRODYNAMIC DATA FOR VALIDATION OF CFD BASED PREDICTIONS FOR SLURRY BUBBLE COLUMN REACTORS  

DOE Green Energy (OSTI)

The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.

Donna Post Guillen; Daniel S. Wendt

2007-11-01T23:59:59.000Z

325

REVIEW OF EXPERIMENTAL CAPABILITIES AND HYDRODYNAMIC DATA FOR VALIDATION OF CFD-BASED PREDICTIONS FOR SLURRY BUBBLE COLUMN REACTORS  

DOE Green Energy (OSTI)

The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.

Donna Post Guillen; Daniel S. Wendt; Steven P. Antal; Michael Z. Podowski

2007-11-01T23:59:59.000Z

326

Multidimensional hydrodynamic plasma-wall model for collisional plasma discharges with and without magnetic-field effects  

SciTech Connect

A numerical model for two-species plasma involving electrons and ions at pressure of 0.1 torr is presented here. The plasma-wall problem is modeled using one- and two-dimensional hydrodynamic equations coupled with Poisson equation. The model utilizes a finite-element algorithm to overcome the stiffness of the resulting plasma-wall equations. The one-dimensional result gives insight into the discharge characteristics including net charge density, electric field, and temporal space-charge sheath evolution. In two dimensions, the plasma formation over a flat plate is investigated for three different cases. The numerical algorithm is first benchmarked with published literature for plasma formed between symmetric electrodes in nitrogen gas. The characteristics of plasma are then analyzed for an infinitesimally thin electrode under dc and rf potentials in the presence of applied magnetic field using argon as a working gas. The magnetic field distorts the streamwise distribution because of a large y-momentum VxB coupling. Finally, the shape effects of the insulator-conductor edge for an electrode with finite thickness have been compared using a 90 degree sign shoulder and a 45 deg. chamfer. The 90 deg. chamfer displays a stronger body force created due to plasma in the downward and forward directions.

Kumar, Haribalan; Roy, Subrata [Computational Plasma Dynamics Laboratory, Kettering University, Flint, Michigan 48504 (United States)

2005-09-15T23:59:59.000Z

327

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

Science Conference Proceedings (OSTI)

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

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

2010-11-15T23:59:59.000Z

328

Numerically Simulating the Hydrodynamic and Water Quality Environment for Migrating Salmon in the Lower Snake River, 2002-2003 Technical Report.  

DOE Green Energy (OSTI)

Summer temperatures in the Lower Snake River can be altered by releasing cold waters that originate from deep depths within Dworshak Reservoir. These cold releases are used to lower temperatures in the Clearwater and Lower Snake Rivers and to improve hydrodynamic and water quality conditions for migrating aquatic species. This project monitored the complex three-dimensional hydrodynamic and thermal conditions at the Clearwater and Snake River confluence and the processes that led to stratification of Lower Granite Reservoir (LGR) during the late spring, summer, and fall of 2002. Hydrodynamic, water quality, and meteorological conditions around the reservoir were monitored at frequent intervals, and this effort is continuing in 2003. Monitoring of the reservoir is a multi-year endeavor, and this report spans only the first year of data collection. In addition to monitoring the LGR environment, a three-dimensional hydrodynamic and water quality model has been applied. This model uses field data as boundary conditions and has been applied to the entire 2002 field season. Numerous data collection sites were within the model domain and serve as both calibration and validation locations for the numerical model. Errors between observed and simulated data varied in magnitude from location to location and from one time to another. Generally, errors were small and within expected ranges, although, as additional 2003 field data becomes available, model parameters may be improved to minimize differences between observed and simulated values. A two-dimensional, laterally-averaged hydrodynamic and water quality model was applied to the three reservoirs downstream of LGR (the pools behind Little Goose, Lower Monumental, and Ice Harbor Dams). A two-dimensional model is appropriate for these reservoirs because observed lateral thermal variations during summer and fall 2002 were almost negligible; however, vertical thermal variations were quite large (see USACE 2003). The numerical model was applied to each reservoir independently to simulate the time period between May 1 and October 1, 2002. Differences between observed and simulated data were small, although improvements to model coefficients may be performed as additional thermal data, collected in the reservoirs during 2003, becomes available.

Cook, C.; Richmond, M.; Coleman, A. (Pacific Northwest National Laboratory)

2003-06-01T23:59:59.000Z

329

P-23 Highlights 6/10/12: Cygnus Dual Beam Radiographic Facility Refurbishment completed at U1A tunnel in Nevada NNSS meeting Level 2 milestone  

Science Conference Proceedings (OSTI)

A moratorium was placed on U.S. underground nuclear testing in 1992. In response, the Stockpile Stewardship Program was created to maintain readiness of the existing nuclear inventory through several efforts such as computer modeling, material analysis, and subcritical nuclear experiments (SCEs). As in the underground test era, the Nevada National Security Site (NNSS), formerly the Nevada Test Site, provides a safe and secure environment for SCEs by the nature of its isolated and secure facilities. A major tool for SCE diagnosis installed in the 05 drift laboratory is a high energy x-ray source used for time resolved imaging. This tool consists of two identical sources (Cygnus 1 and Cygnus 2) and is called the Cygnus Dual Beam Radiographic Facility (Figs. 2-6). Each Cygnus machine has 5 major elements: Marx Generator, Pulse Forming Line (PFL), Coaxial Transmission Line (CTL), 3-cell Inductive Voltage Adder (IVA), and Rod Pinch Diode. Each machine is independently triggered and may be fired in separate tests (staggered mode), or in a single test where there is submicrosecond separation between the pulses (dual mode). Cygnus must operate as a single shot machine since on each pulse the diode electrodes are destroyed. The diode is vented to atmosphere, cleaned, and new electrodes are inserted for each shot. There is normally two shots per day on each machine. Since its installation in 2003, Cygnus has participated in: 4 Subcritical Experiments (Armando, Bacchus, Barolo A, and Barolo B), a 12 shot plutonium physics series (Thermos), and 2 plutonium step wedge calibration series (2005, 2011), resulting in well over 1000 shots. Currently the Facility is in preparation for 2 SCEs scheduled for this calendar year - Castor and Pollux. Cygnus has performed well during 8 years of operations at NNSS. Many improvements in operations and performance have been implemented during this time. Throughout its service at U1a, major maintenance and replacement of many hardware items were delayed due to programmatic requirements. It is anticipated that Cygnus will be in service at U1a for another 5 years. With this assumption, it was realized that significant resources and effort should be allotted to bring the hardware back to its original condition, or even to improve elements when appropriate. The Cygnus Refurbishment and Enhancement Project started in April, 2011 with the intent to encompass a major overhaul of Cygnus.

Deyoung, Anemarie [Los Alamos National Laboratory; Smith, John R. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

330

Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model  

DOE Green Energy (OSTI)

Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be used to assess whether a prescribed mitigation is likely to meet intended objectives from both a water quality and a biological resource perspective. These techniques can be used to assess the tradeoffs between hydropower operations, power generation, and environmental quality.

Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL

2006-07-01T23:59:59.000Z

331

Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir  

SciTech Connect

The phase distribution of trace metals and oxyanions was investigated within a South Texas watershed hosting a high density of surface uranium mine pits and tailings. The objectives of the study were to evaluate the potential impact of these old uranium mining sites on the watershed with particular emphasis on spatial and temporal changes in water quality of a reservoir that serves as the major source of freshwater to a population of {approx} 350,000 people in the region. A livestock pond, bordered by uranium mine tailings, was used as a model case-study site to evaluate the cycling of uranium mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which seemed to be mostly associated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the ponds hypolimnion. Uranium levels, however, were too low to support strong inputs from th e tailings into the water column of the pond. The strong relations observed between particulate Cr, Cs, V and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous aluminosilicates) enriched in unreactive iron. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processed (and histories) in the basin. Arsenic, though selectively enriched in the ponds water column, remained stable and mostly in solution throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. We found no evidence of anthropogenic impacts of U mines beyond the purely local scale. Arsenic does decrease in concentration downstream of uranium mining sites but its presence within the Nueces drainage basin is related to interactions between surface and ground waters with uranium-rich geological formations rather than long-scale transport of contaminants downstream of the U mine pits and tailings. As in Lyssy pond, arsenic (and other oxyanions) in Lake Corpus Christi's water column are not affected by the abundant presence of Fe-rich particles but instead behave conservatively throughout the entire period of study. A quantitative mass balance model, constructed using monthly hydrological data for the reservoir, provides quantitative evidence of seasonal evaporative concentration of as in surface waters demonstrating the predominance of hydrodynamic constraints, over geochemical ones, on the cycling of this metal in selected aquatic systems.

Brandenberger, Jill M.; Louchouarn, Patrick; Herbert, Bruce; Tissot, Philippe

2004-10-01T23:59:59.000Z

332

Hydrodynamical simulations of the jet in the symbiotic star MWC 560 III. Application to X-ray jets in symbiotic stars  

E-Print Network (OSTI)

In papers I and II in this series, we presented hydrodynamical simulations of jet models with parameters representative of the symbiotic system MWC 560. These were simulations of a pulsed, initially underdense jet in a high density ambient medium. Since the pulsed emission of the jet creates internal shocks and since the jet velocity is very high, the jet bow shock and the internal shocks are heated to high temperatures and should therefore emit X-ray radiation. In this paper, we investigate in detail the X-ray properties of the jets in our models. We have focused our study on the total X-ray luminosity and its temporal variability, the resulting spectra and the spatial distribution of the emission. Temperature and density maps from our hydrodynamical simulations with radiative cooling presented in the second paper are used together with emissivities calculated with the atomic database ATOMDB. The jets in our models show extended and variable X-ray emission which can be characterized as a sum of hot and warm components with temperatures that are consistent with observations of CH Cyg and R Aqr. The X-ray spectra of our model jets show emission line features which correspond to observed features in the spectra of CH Cyg. The innermost parts of our pulsed jets show iron line emission in the 6.4 - 6.7 keV range which may explain such emission from the central source in R Aqr. We conclude that MWC 560 should be detectable with Chandra or XMM-Newton, and such X-ray observations will provide crucial for understanding jets in symbiotic stars.

Matthias Stute; Raghvendra Sahai

2007-04-17T23:59:59.000Z

333

Design of a 7-MV Linear Transformer Driver (LTD) for down-hole flash x-ray radiography.  

Science Conference Proceedings (OSTI)

Pulsed power driven flash x-ray radiography is a valuable diagnostic for subcritical experiments at the Nevada Test Site. The existing dual-axis Cygnus system produces images using a 2.25 MV electron beam diode to produce intense x-rays from a small source. Future hydrodynamic experiments will likely use objects with higher areal mass, requiring increased x-ray dose and higher voltages while maintaining small source spot size. A linear transformer driver (LTD) is a compact pulsed power technology with applications ranging from pulsed power flash x-ray radiography to high current Z-pinch accelerators. This report describes the design of a 7-MV dual-axis system that occupies the same lab space as the Cygnus accelerators. The work builds on a design proposed in a previous report [1]. This new design provides increased diode voltage from a lower impedance accelerator to improve coupling to low impedance diodes such as the self magnetic pinch (SMP) diode. The design also improves the predicted reliability by operating at a lower charge voltage and removing components that have proven vulnerable to failure. Simulations of the new design and experimental results of the 1-MV prototype are presented.

Cordova, Steve Ray; Welch, Dale Robert (Voss Scientific, Albuquerque, NM); Oliver, Bryan Velten; Rose, David Vincent (Voss Scientific, Albuquerque, NM); Johnson, David Lee (L-3 Communications - Pulse Sciences, San Leandro, CA); Bruner, Nichelle Lee (Voss Scientific, Albuquerque, NM); Leckbee, Joshua J.

2008-09-01T23:59:59.000Z

334

LUMINOSITY DISTRIBUTION OF GAMMA-RAY BURST HOST GALAXIES AT REDSHIFT z = 1 IN COSMOLOGICAL SMOOTHED PARTICLE HYDRODYNAMIC SIMULATIONS: IMPLICATIONS FOR THE METALLICITY DEPENDENCE OF GRBs  

SciTech Connect

We study the relationship between the metallicity of gamma-ray burst (GRB) progenitors and the probability distribution function (PDF) of GRB host galaxies as a function of luminosity using cosmological hydrodynamic simulations of galaxy formation. We impose a maximum limit to the gas metallicity in which GRBs can occur and examine how the predicted luminosity PDF of GRB host galaxies changes in the simulation. We perform the Kolmogorov-Smirnov test and show that the result from our simulation agrees with the observed luminosity PDF of core-collapse supernovae (SNe) host galaxies when we assume that the core-collapse SNe trace star formation. When we assume that GRBs occur only in a low-metallicity environment with Z {approx}< 0.1 Z{sub sun}, GRBs occur in lower luminosity galaxies, and the simulated luminosity PDF becomes quantitatively consistent with the observed one. The observational bias against the host galaxies of optically dark GRBs owing to dust extinction may be another reason for the lower luminosities of GRB host galaxies, but the observed luminosity PDF of GRB host galaxies cannot be reproduced solely by the dust bias in our simulation.

Niino, Yuu; Totani, Tomonori [Department of Astronomy, School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Choi, Jun-Hwan; Nagamine, Kentaro; Zhang Bing [Department of Physics and Astronomy, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154-4002 (United States); Kobayashi, Masakazu A. R., E-mail: niinou@kusastro.kyoto-u.ac.jp [Optical and Infrared Astronomy Division, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)

2011-01-10T23:59:59.000Z

335

HYDRODYNAMIC MODELS FOR SLURRY BUBBLE COLUMN REACTORS. FINAL TECHNICAL REPORT ALSO INCLUDES THE QUARTERLY TECHNICAL REPORT FOR THE PERIOD 01/01/1997 - 03/31/1997.  

DOE Green Energy (OSTI)

The objective of this study is to develop a predictive experimentally verified computational fluid dynamic (CFD) three phase model. It predicts the gas, liquid and solid hold-ups (volume fractions) and flow patterns in the industrially important bubble-coalesced (churn-turbulent) regime. The input into the model can be either particulate viscosities as measured with a Brookfield viscometer or effective restitution coefficient for particles. A combination of x-ray and {gamma}-ray densitometers was used to measure solid and liquid volume fractions. There is a fair agreement between the theory and the experiment. A CCD camera was used to measure instantaneous particle velocities. There is a good agreement between the computed time average velocities and the measurements. There is an excellent agreement between the viscosity of 800 {micro}m glass beads obtained from measurement of granular temperature (random kinetic energy of particles) and the measurement using a Brookfield viscometer. A relation between particle Reynolds stresses and granular temperature was found for developed flow. Such measurement and computations gave a restitution coefficient for a methanol catalyst to be about 0.9. A transient, two-dimensional hydrodynamic model for production of methanol from syn-gas in an Air Products/DOE LaPorte slurry bubble column reactor was developed. The model predicts downflow of catalyst at the walls and oscillatory particle and gas flow at the center, with a frequency of about 0.7 Hertz. The computed temperature variation in the rector with heat exchangers was only about 5 K, indicating good thermal management. The computed slurry height, the gas holdup and the rate of methanol production agree with LaPorte's reported data. Unlike the previous models in the literature, this model computes the gas and the particle holdups and the particle rheology. The only adjustable parameter in the model is the effective particle restitution coefficient.

DIMITRI GIDASPOW

1997-08-15T23:59:59.000Z

336

Attenuation-based estimation of patient size for the purpose of size specific dose estimation in CT. Part II. Implementation on abdomen and thorax phantoms using cross sectional CT images and scanned projection radiograph images  

SciTech Connect

Purpose: To estimate attenuation using cross sectional CT images and scanned projection radiograph (SPR) images in a series of thorax and abdomen phantoms. Methods: Attenuation was quantified in terms of a water cylinder with cross sectional area of A{sub w} from both the CT and SPR images of abdomen and thorax phantoms, where A{sub w} is the area of a water cylinder that would absorb the same dose as the specified phantom. SPR and axial CT images were acquired using a dual-source CT scanner operated at 120 kV in single-source mode. To use the SPR image for estimating A{sub w}, the pixel values of a SPR image were calibrated to physical water attenuation using a series of water phantoms. A{sub w} and the corresponding diameter D{sub w} were calculated using the derived attenuation-based methods (from either CT or SPR image). A{sub w} was also calculated using only geometrical dimensions of the phantoms (anterior-posterior and lateral dimensions or cross sectional area). Results: For abdomen phantoms, the geometry-based and attenuation-based methods gave similar results for D{sub w}. Using only geometric parameters, an overestimation of D{sub w} ranging from 4.3% to 21.5% was found for thorax phantoms. Results for D{sub w} using the CT image and SPR based methods agreed with each other within 4% on average in both thorax and abdomen phantoms. Conclusions: Either the cross sectional CT or SPR images can be used to estimate patient attenuation in CT. Both are more accurate than use of only geometrical information for the task of quantifying patient attenuation. The SPR based method requires calibration of SPR pixel values to physical water attenuation and this calibration would be best performed by the scanner manufacturer.

Wang Jia; Christner, Jodie A.; Duan Xinhui; Leng Shuai; Yu Lifeng; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

2012-11-15T23:59:59.000Z

337

Hydrodynamics of the cascading plasma  

E-Print Network (OSTI)

The cascading gauge theory of Klebanov et.al realizes a soluble example of gauge/string correspondence in a non-conformal setting. Such a gauge theory has a strong coupling scale Lambda, below which it confines with a chiral symmetry breaking. A holographic description of a strongly coupled cascading gauge theory plasma is represented by a black brane solution of type IIB supergravity on a conifold with fluxes. A characteristic parameter controlling the high temperature expansion of such plasma is 1/ln(T/Lambda). In this paper we study the speed of sound and the bulk viscosity of the cascading gauge theory plasma to order 1/ln(T/Lambda)^4. We find that the bulk viscosity satisfies the bound conjectured in arXiv:0708.3459. We comment on difficulties of computing the transport coefficients to all orders in T/Lambda. Previously, it was shown that a cascading gauge theory plasma undergoes a first-order deconfinement transition with unbroken chiral symmetry at T_c=0.6141111(3) Lambda. We show here that a deconfined chirally symmetric phase becomes perturbatively unstable at T_u=0.8749(0) T_c. Near the unstable point the specific heat diverges as c_V ~ |1-T_u/T|^(-1/2).

Alex Buchel

2009-03-20T23:59:59.000Z

338

Hydrodynamic lift on bound vesicles  

E-Print Network (OSTI)

Bound vesicles subject to lateral forces such as arising from shear flow are investigated theoretically by combining a lubrication analysis of the bound part with a scaling approach to the global motion. A minor inclination of the bound part leads to significant lift due to the additive effects of lateral and tank-treading motions. With increasing shear rate, the vesicle unbinds from the substrate at a critical value. Estimates are in agreement with recent experimental data.

Udo Seifert

1999-01-12T23:59:59.000Z

339

Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models  

Science Conference Proceedings (OSTI)

The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are the closures for the various ''turbulence'' terms involving the unknown variables from the fluctuating (RANS) or from the subgrid (LES) parts. Even though the hydrodynamic and thermodynamic models for RANS and LES have the same set of Partial Differential Equations, the physical interpretations of these PDEs cannot be the same, i.e., RANS models an averaged field, while LES simulates a filtered field. In this manuscript, we also demonstrate that this multiphase model fully fulfills the second law of thermodynamics and fulfills the necessary requirements for a well-posed initial-value problem. In the next manuscripts, we will further develop specific closures for multiphase RANS, LES, and hybrid-LES.

S. Dartevelle

2005-09-05T23:59:59.000Z

340

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341

Hydrodynamic/kinetic reactions in liquid dominated geothermal systems: Hydroscale Test Program, Mercer 2 well site South Brawley, California (Tests No. 15--20). Final report, 27 October 1980--6 February 1981  

DOE Green Energy (OSTI)

The Aerojet Energy Conversion Company, under contract to the Los Alamos National Laboratory, US Department of Energy, has constructed and tested a mobile geothermal well-site test unit at the Mercer 2 well in South Brawley, California (Imperial Valley). The equipment controlled, monitored, and recorded all process conditions of single- and dual-flash power cycles. Single- and two-phase flashed brine effluents were flowed through piping component test sections to provide hydrodynamic/kinetic data for scale formation. The unit operated at flowrates in excess of 200 gpm and is designed to accommodate flowrates up to 300 gpm. Primary scale formations encountered were those of Pbs, Fe{sub 2} (OH){sub 3}Cl (iron hydroxychloride), iron chlorides, and non-crystalline forms Of SiO{sub 2}. The formation of iron hydroxychloride was due to the unusually high concentration of iron in the wellhead brine (5000 mg/1).

Nesewich, J.P.; Gracey, C.M. [Los Alamos National Lab., NM (United States)

1982-04-01T23:59:59.000Z

342

Accepted to ApJL Preprint typeset using L ATEX style emulateapj v. 6/22/04 INTERNAL ALIGNMENT OF THE HALOS OF DISK GALAXIES IN COSMOLOGICAL HYDRODYNAMIC SIMULATIONS  

E-Print Network (OSTI)

Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find that the orientation of the outer halo, beyond ? 0.1 rvir, is unaffected by the presence of the disk. In contrast, the inner halo is aligned such that the halo minor axis aligns with the disk axis. The relative orientation of these two regions of the halo are uncorrelated. The alignment of the disk and inner halo appears to take place simultaneously through their joint evolution. The disconnect between these two regions of the halo should be taken into account when modelling tidal streams in the halos of disk galaxies and when calculating intrinsic alignments of disk galaxies based on the properties of dark matter halos.

Jeremy Bailin; Daisuke Kawata; Brad K. Gibson; Matthias Steinmetz; Julio F. Navarro; Chris B; Stuart P. D. Gill; Rodrigo A. Ibata; Er Knebe; Geraint F. Lewis; Takashi Okamoto

2005-01-01T23:59:59.000Z

343

Microsoft Word - DSQ Winter 2010_15mar10.doc  

National Nuclear Security Administration (NNSA)

Distribution Measurements 4 2009 Dawson Award of Excellence 4 NSTec Livermore Operations Energy Milestone 5 H3837: DARHT's First Dual-Axis Shot 5 NLUF Experiment Published in...

344

Open Quantum to classical phases transition in the stochastic hydrodynamic analogy: the explanation of the Lindemann relation and the analogies between the maximum of density at He lambda point and that one at water-ice phase transition  

E-Print Network (OSTI)

In the present paper the gas, liquid and solid phases made of structureless particles, are visited to the light of the quantum stochastic hydrodynamic analogy (SQHA). The SQHA shows that the open quantum mechanical behavior is maintained on a distance shorter than the theory-defined quantum correlation length (lc). When, the physical length of the problem is larger than lc, the model shows that the quantum (potential) interactions may have a finite range of interaction maintaining the non-local behavior on a finite distance quantum non-locality length lq. The present work shows that when the mean molecular distance is larger than the quantum non-locality length we have a classical phases (gas and van der Waals liquids) while when the mean molecular distance becomes smaller than lq or than lc we have phases such as the solid crystal or the superfluid one, respectively, that show quantum characteristics. The model agrees with Lindemann empirical law (and explains it), for the mean square deviation of atom from the equilibrium position at melting point of crystal, and shows a connection between the maximum density at the He lambda point and that one near the water-ice solidification point.

Piero Chiarelli

2013-05-07T23:59:59.000Z

345

TESTING METGLAS FOR USE IN DARHT ACCELERATOR CELLS  

SciTech Connect

The Dual Axis Radiographic Hydrotest Facility [DARHT] at Los Alamos will use two induction linacs to produce high-energy electron beams. The electron beams will be used to generate x-rays from bremsstrahlung targets. The x-rays will be used to produce radiographs. The first accelerator is operational now, producing a 60-nanosecond electron beam. The second accelerator is under construction. It will produce a 2-microsecond electron beam. The 78 induction cells of the second axis accelerator require a total Metglas capacity of approximately 40 volt seconds of flux. Four Metglas cores are used in each of the 5-foot diameter accelerator cells. Each Metglas core weighs approximately 3000 pounds. This paper presents the measurement techniques and results of the Metglas tests. Routine automated analysis and archival of the pulse data provided hysteresis curves, energy loss curves and total flux swing in the operating regime. Results of the tests were used to help the manufacturer improve quality control and increase the average flux swing of the cores. Results of the tests were used to match Metglas cores and to assemble accelerator cells with equal volt-second ratings.

E.A. ROSE; D.A. DALMAS; J.N. DOWNING; R.D. TEMPLE

2001-06-01T23:59:59.000Z

346

Simulation of Magneto-Hydrodynamics with Least-  

E-Print Network (OSTI)

parts(artificial heart, liquid metal pumps) · Compact heat exchangers · Shock absorbers, active damping · Manufacturing(solidification,crystal growth) · Flow control · Drag reduction/propulsion · Pumps with no moving PCG ·Support for multiple material domains such as in conjugate heat transfer problems ·Nonlinear

Dennis, Brian

347

Electromagnetotoroid Structures and their Hydrodynamic Analogs  

E-Print Network (OSTI)

We introduce the concept of an electromagnetotoroid in astrophysics, and explore its role in polar jets. This model represents the onset of Abraham's force driven by some external source, for example, the infall of gas towards a star. The Abraham's force term is analogous to the Magnus force, and thus represents the formation of electromagnetic vortex structures in the fabric of space-time. In principle, the proposed toroidal field structure can also provide force spaceship propulsion.

Mario J. Pinheiro

2012-03-08T23:59:59.000Z

348

Flotation Hydrodynamic Measurements for Circuit Benchmarking at ...  

Science Conference Proceedings (OSTI)

Transfer and Consumption of Oxygen in Gold-bearing Sulfide Ores: Agnico-eagle Mines Trials · Tundish Process Performance Improvement: Some Indian Case ...

349

Hydrodynamic Loading on Offshore Wind Turbines  

E-Print Network (OSTI)

This contribution to the OWTES project has been carried out under contract JOR3-CT98-0284 awarded by the European Union. This work has been co-financed by NOVEM under contract 224.750-9854.

Owtes Task

2003-01-01T23:59:59.000Z

350

13.021 Marine Hydrodynamics, Fall 2001  

E-Print Network (OSTI)

The fundamentals of fluid mechanics are developed in the context of naval architecture and ocean science and engineering. Transport theorem and conservation principles. Navier-Stokes' equation. Dimensional analysis. Ideal ...

Yue, Dick Kau-Ping

351

Workshop on advances in smooth particle hydrodynamics  

SciTech Connect

This proceedings contains viewgraphs presented at the 1993 workshop held at Los Alamos National Laboratory. Discussed topics include: negative stress, reactive flow calculations, interface problems, boundaries and interfaces, energy conservation in viscous flows, linked penetration calculations, stability and consistency of the SPH method, instabilities, wall heating and conservative smoothing, tensors, tidal disruption of stars, breaking the 10,000,000 particle limit, modelling relativistic collapse, SPH without H, relativistic KSPH avoidance of velocity based kernels, tidal compression and disruption of stars near a supermassive rotation black hole, and finally relativistic SPH viscosity and energy.

Wingate, C.A.; Miller, W.A.

1993-12-31T23:59:59.000Z

352

MHD duct flows under hydrodynamic “slip” condition  

E-Print Network (OSTI)

metal blankets of a fusion reactor), H a ? 10 3 ? 10 5 . Ineld typical to future fusion reactors, the estimate for thewith those in the fusion reactor, are used. Finally, it

Smolentsev, S.

2009-01-01T23:59:59.000Z

353

Current SPE Hydrodynamic Modeling and Path Forward  

SciTech Connect

Extensive work has been conducted on SPE analysis efforts: Fault effects Non-uniform weathered layer analysis MUNROU: material library incorporation, parallelization, and development of non-locking tets Development of a unique continuum-based-visco-plastic strain-rate-dependent material model With corrected SPE data path is now set for a multipronged approach to fully understand experimental series shot effects.

Knight, Earl E. [Los Alamos National Laboratory; Rougier, Esteban [Los Alamos National Laboratory

2012-08-14T23:59:59.000Z

354

Internal Gravity Wave Generation and Hydrodynamic Instability  

Science Conference Proceedings (OSTI)

Two mechanisms are proposed whereby internal gravity waves (IGW) may radiate from a linearly unstable region of Boussinesq parallel flow that is characterized in the far field by constant horizontal velocity and Brunt-Väisälä frequency. Through ...

B. R. Sutherland; C. P. Caulfield; W. R. Peltier

1994-11-01T23:59:59.000Z

355

An hydrodynamic shear instability in stratified disks  

E-Print Network (OSTI)

We discuss the possibility that astrophysical accretion disks are dynamically unstable to non-axisymmetric disturbances with characteristic scales much smaller than the vertical scale height. The instability is studied using three methods: one based on the energy integral, which allows the determination of a sufficient condition of stability, one using a WKB approach, which allows the determination of the necessary and sufficient condition for instability and a last one by numerical solution. This linear instability occurs in any inviscid stably stratified differential rotating fluid for rigid, stress-free or periodic boundary conditions, provided the angular velocity $\\Omega$ decreases outwards with radius $r$. At not too small stratification, its growth rate is a fraction of $\\Omega$. The influence of viscous dissipation and thermal diffusivity on the instability is studied numerically, with emphasis on the case when $d \\ln \\Omega / d \\ln r =-3/2$ (Keplerian case). Strong stratification and large diffusivity are found to have a stabilizing effect. The corresponding critical stratification and Reynolds number for the onset of the instability in a typical disk are derived. We propose that the spontaneous generation of these linear modes is the source of turbulence in disks, especially in weakly ionized disks.

B. Dubrulle; L. Marié; Ch. Normand; D. Richard; F. Hersant; J. -P. Zahn

2004-10-08T23:59:59.000Z

356

TOWARD END-TO-END MODELING FOR NUCLEAR EXPLOSION MONITORING: SIMULATION OF UNDERGROUND NUCLEAR EXPLOSIONS AND EARTHQUAKES USING HYDRODYNAMIC AND ANELASTIC SIMULATIONS, HIGH-PERFORMANCE COMPUTING AND THREE-DIMENSIONAL EARTH MODELS  

Science Conference Proceedings (OSTI)

This paper describes new research being performed to improve understanding of seismic waves generated by underground nuclear explosions (UNE) by using full waveform simulation, high-performance computing and three-dimensional (3D) earth models. The goal of this effort is to develop an end-to-end modeling capability to cover the range of wave propagation required for nuclear explosion monitoring (NEM) from the buried nuclear device to the seismic sensor. The goal of this work is to improve understanding of the physical basis and prediction capabilities of seismic observables for NEM including source and path-propagation effects. We are pursuing research along three main thrusts. Firstly, we are modeling the non-linear hydrodynamic response of geologic materials to underground explosions in order to better understand how source emplacement conditions impact the seismic waves that emerge from the source region and are ultimately observed hundreds or thousands of kilometers away. Empirical evidence shows that the amplitudes and frequency content of seismic waves at all distances are strongly impacted by the physical properties of the source region (e.g. density, strength, porosity). To model the near-source shock-wave motions of an UNE, we use GEODYN, an Eulerian Godunov (finite volume) code incorporating thermodynamically consistent non-linear constitutive relations, including cavity formation, yielding, porous compaction, tensile failure, bulking and damage. In order to propagate motions to seismic distances we are developing a one-way coupling method to pass motions to WPP (a Cartesian anelastic finite difference code). Preliminary investigations of UNE's in canonical materials (granite, tuff and alluvium) confirm that emplacement conditions have a strong effect on seismic amplitudes and the generation of shear waves. Specifically, we find that motions from an explosion in high-strength, low-porosity granite have high compressional wave amplitudes and weak shear waves, while an explosion in low strength, high-porosity alluvium results in much weaker compressional waves and low-frequency compressional and shear waves of nearly equal amplitude. Further work will attempt to model available near-field seismic data from explosions conducted at NTS, where we have accurate characterization of the sub-surface from the wealth of geological and geophysical data from the former nuclear test program. Secondly, we are modeling seismic wave propagation with free-surface topography in WPP. We have model the October 9, 2006 and May 25, 2009 North Korean nuclear tests to investigate the impact of rugged topography on seismic waves. Preliminary results indicate that the topographic relief causes complexity in the direct P-waves that leads to azimuthally dependent behavior and the topographic gradient to the northeast, east and southeast of the presumed test locations generate stronger shear-waves, although each test gives a different pattern. Thirdly, we are modeling intermediate period motions (10-50 seconds) from earthquakes and explosions at regional distances. For these simulations we run SPECFEM3D{_}GLOBE (a spherical geometry spectral element code). We modeled broadband waveforms from well-characterized and well-observed events in the Middle East and central Asia, as well as the North Korean nuclear tests. For the recent North Korean test we found that the one-dimensional iasp91 model predicts the observed waveforms quite well in the band 20-50 seconds, while waveform fits for available 3D earth models are generally poor, with some exceptions. Interestingly 3D models can predict energy on the transverse component for an isotropic source presumably due to surface wave mode conversion and/or multipathing.

Rodgers, A; Vorobiev, O; Petersson, A; Sjogreen, B

2009-07-06T23:59:59.000Z

357

Radiographic Capabilities of the MERCURY Monte Carlo Code  

Science Conference Proceedings (OSTI)

Radiography / Special Issue on the 11th International Conference on Radiation Shielding and the 15th Topical Meeting of the Radiation Protection and Shielding Division (Part 1) / Radioisotopes

M. Scott McKinley; Alexis E. Schach von Wittenau

358

Silver Recovery from Waste Radiographic Films Using Different ...  

Science Conference Proceedings (OSTI)

Aerosol Route Synthesis of Copper Oxide Nanoparticles Using Copper Nitrate Solution · AlGaAs-Based Optical ... Defect Energetics and Fission Product Transport in ZrC ... Enhancing Mineral Beneficiation by High Intensity Power Ultrasound.

359

Fluctuating hydrodynamics of multispecies mixtures. I. Non-reacting Flows  

E-Print Network (OSTI)

In this paper we discuss the formulation of the fluctuating Navier-Stokes (FNS) equations for multi-species, non-reactive fluids. In particular, we establish a form suitable for numerical solution of the resulting stochastic partial differential equations. An accurate and efficient numerical scheme, based on our previous methods for single species and binary mixtures, is presented and tested at equilibrium as well as for a variety of non-equilibrium problems. These include the study of giant nonequilibrium concentration fluctuations in a ternary mixture in the presence of a diffusion barrier, the triggering of a Rayleigh-Taylor instability by diffusion in a four-species mixture, as well as reverse diffusion in a ternary mixture. Good agreement with theory and experiment demonstrates that the formulation is robust and can serve as a useful tool in the study of thermal fluctuations for multi- species fluids. The extension to include chemical reactions will be treated in a sequel paper.

Balakrishnan, Kaushik; Donev, Aleksandar; Bell, John B

2013-01-01T23:59:59.000Z

360

Hydrodynamical Simulations of Strong Tides in Astrophysical Systems  

E-Print Network (OSTI)

Skinner, G. EXIST’s Gamma-Ray Burst Sensitivity. ApJ Barnes,E. The progenitors of short gamma-ray bursts. New Journal ofde Ven, G. Short Gamma-ray Bursts from Dynamically Assembled

Guillochon, James Francis

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Dissipation and Heating in Supersonic Hydrodynamic and MHD Turbulence  

E-Print Network (OSTI)

We study energy dissipation and heating by supersonic MHD turbulence in molecular clouds using Athena, a new higher-order Godunov code. We analyze the dependence of the saturation amplitude, energy dissipation characteristics, power spectra, sonic scaling, and indicators of intermittency in the turbulence on factors such as the magnetic field strength, driving scale, energy injection rate, and numerical resolution. While convergence in the energies is reached at moderate resolutions, we find that the power spectra require much higher resolutions that are difficult to obtain. In a 1024^3 hydro run, we find a power law relationship between the velocity dispersion and the spatial scale on which it is measured, while for an MHD run at the same resolution we find no such power law. The time-variability and temperature intermittency in the turbulence both show a dependence on the driving scale, indicating that numerically driving turbulence by an arbitrary mechanism may not allow a realistic representation of these properties. We also note similar features in the power spectrum of the compressive component of velocity for supersonic MHD turbulence as in the velocity spectrum of an initially-spherical MHD blast wave, implying that the power law form does not rule out shocks, rather than a turbulent cascade, playing a significant role in the regulation of energy transfer between spatial scales.

M. Nicole Lemaster; James M. Stone

2008-09-23T23:59:59.000Z

362

Dissipation and Heating in Supersonic Hydrodynamic and MHD Turbulence  

E-Print Network (OSTI)

We study energy dissipation and heating by supersonic MHD turbulence in molecular clouds using Athena, a new higher-order Godunov code. We analyze the dependence of the saturation amplitude, energy dissipation characteristics, power spectra, sonic scaling, and indicators of intermittency in the turbulence on factors such as the magnetic field strength, driving scale, energy injection rate, and numerical resolution. While convergence in the energies is reached at moderate resolutions, we find that the power spectra require much higher resolutions that are difficult to obtain. In a 1024^3 hydro run, we find a power law relationship between the velocity dispersion and the spatial scale on which it is measured, while for an MHD run at the same resolution we find no such power law. The time-variability and temperature intermittency in the turbulence both show a dependence on the driving scale, indicating that numerically driving turbulence by an arbitrary mechanism may not allow a realistic representation of these...

Lemaster, M Nicole

2008-01-01T23:59:59.000Z

363

A Hydrodynamical Approach to CMB mu-distortions  

E-Print Network (OSTI)

Spectral distortion of the cosmic microwave background provides a unique opportunity to probe primordial perturbations on very small scales by performing large-scale measurements. We discuss in a systematic and pedagogic way all the relevant physical phenomena involved in the production and evolution of the mu-type spectral distortion. Our main results agree with previous estimates (in particular we show that a recently found factor of 3/4 arises from relativistic corrections to the wave energy). We also discuss several subleading corrections such as adiabatic cooling and the effects of bulk viscosity, baryon loading and photon heat conduction. Finally we calculate the transfer function for mu-distortions between the end of the mu-era and now.

Enrico Pajer; Matias Zaldarriaga

2012-06-20T23:59:59.000Z

364

KIVA--Hydrodynamics Model for Chemically Reacting Flow ...  

Simulation of an experimental engine with DOHC quasi-symmetric pent-roof combustion chamber and 4 valves.

365

The Dramatic Impact of Hydrodynamic Mixing on Supernova Progenitors  

E-Print Network (OSTI)

. Section 2 describes hydro simulations of the oxygen and carbon burning shells and their implications spectroscopic binary EM Car. Apsidal motion of the binary gives us a measurement of size of the convective core

Arnett, W. David

366

Hydrodynamical modeling of targets compression to high densities  

E-Print Network (OSTI)

by composite schemes on moving grid. Both models also include heat conductivity. The quotidian equation, E is total energy and heat flux W is given by W = - grad T (2) where T is temperature and is heat note that for most presented computations the heat conductivity is negligible. The above system

Limpouch, Jiri

367

Hydrodynamics of undulatory fish schooling in lateral configurations  

E-Print Network (OSTI)

The thrust benefits of lateral configurations of two-dimensional undulating fish-like bodies are investigated using high-fidelity numerical simulation. The solution of the Navier--Stokes equations is carried out with a viscous vortex particle method. Configurations of tethered pairs of fish arranged side by side are studied by varying the lateral separation distance and relative phase difference. It is shown that, in mirroring symmetry, the fish in the pair augment each other's thrust even at relatively large separations (up to ten body lengths). At small distances, this augmentation is primarily brought about by a peristaltic pumping in the gap between the fish, whereas at larger distances, the thrust is affected by subtle changes in the vortex shedding at the tail due to interactions with the other fish. In cases without symmetric undulation, one fish always draws more benefit from the interaction than the other. Finally, lateral configurations with three fish are studied with mirroring symmetry between nei...

Zhang, Li Jeany

2010-01-01T23:59:59.000Z

368

Multi-Material Pressure Relaxation Methods for Lagrangian Hydrodynamic...  

National Nuclear Security Administration (NNSA)

methods seen in those quantities. Also, we describe results of a 1D test problem for a water-air shock tube. SAND 2011-7018A Page 2 Session 10: Computational Physics-Computer...

369

The effect of curvature and topology on membrane hydrodynamics  

E-Print Network (OSTI)

We study the mobility of extended objects (rods) on a spherical liquid-liquid interface to show how this quantity is modified in a striking manner by both the curvature and the topology of the interface. We present theoretical calculations and experimental measurements of the interfacial fluid velocity field around a moving rod bound to the crowded interface of a water-in-oil droplet. By using different droplet sizes, membrane viscosities, and rod lengths, we show that the viscosity mismatch between the interior and exterior fluids leads to a suppression of the fluid flow on small droplets that cannot be captured by the flat interface predictions.

Mark L. Henle; R. McGorty; A. D. Dinsmore; Alex J. Levine

2007-06-14T23:59:59.000Z

370

Thermodynamic and hydrodynamic behaviour of interacting Fermi gases  

E-Print Network (OSTI)

data processing speed and decreased power consumption. Understanding the spin relaxation, diffusion and other transport properties is of fundamental importance this field. An important advantage of cold gases in studies of spin transport phenomena... of information [39]. Either extending conventional charge-based electronic appliances by the spin degree of free- dom, or using the spin alone can be the foundation for a new generation of “spintronic” devices. Advantages are for instance nonvolatility, increased...

Goulko, Olga

2012-01-10T23:59:59.000Z

371

Hydrodynamic resistance and sorting of deformable particles in microfluidic circuits  

E-Print Network (OSTI)

Sorting of microparticles has numerous applications in science and technology, from cell analysis to sample purification for biomaterials, photonics, and drug delivery. Methods used for particle separation relied only on ...

Cartas Ayala, Marco Aurelio

2013-01-01T23:59:59.000Z

372

Reduction of diffusional defocusing in hydrodynamically focused flows  

DOE Patents (OSTI)

An analyte fluid stream with first molecules having relatively low molecular weight and a corresponding high coefficient of diffusion has reduced diffusional defocusing out of an analyte fluid stream. The analyte fluid stream of first molecules is associated with second molecules of relatively high molecular weight having a relatively low coefficient of diffusion and a binding constant effective to associate with the first molecules. A focused analyte fluid stream is maintained since the combined molecular weight of the associated first and second molecules is effective to minimize diffusion of the first molecules out of the analyte fluid stream.

Affleck, Rhett L. (Lawrenceville, NJ); Demas, James N. (Charlottesville, VA); Goodwin, Peter M. (Jemez Springs, NM); Keller, Richard (Los Alamos, NM); Wu, Ming (Middle Island, NY)

1998-01-01T23:59:59.000Z

373

Modeling of Cast Systems Using Smoothed-Particle Hydrodynamics  

Science Conference Proceedings (OSTI)

Liquid metal (generally aluminum or magnesium) is injected into the die at high ... Examples of other applications include heat conduction,8 natural convection in a .... Flue Gas and Carbon Dioxide,” Metallurgical Transactions B, 8B (1977), pp.

374

Thermodynamics, Hydrodynamics and Critical Phenomena in Strongly Coupled Gauge Theories.  

E-Print Network (OSTI)

??The gauge theory / string theory correspondence has led to great progress in the study of strongly-coupled gauge theories. In this work, we start with… (more)

Pagnutti, Christopher

2011-01-01T23:59:59.000Z

375

A Severe Frontal Rainband. Part I. Stormwide Hydrodynamic Structure  

Science Conference Proceedings (OSTI)

A narrow cold frontal band of intense precipitation is examined by means of triple Doppler radar and supporting observations. As the band passed through the Central Valley of California, it was accompanied by strong gusty winds, electrical ...

Richard E. Carbone

1982-02-01T23:59:59.000Z

376

A class of self-similar hydrodynamics test problems  

SciTech Connect

We consider self-similar solutions to the gas dynamics equations. One such solution - a spherical geometry Gaussian density profile - has been analyzed in the existing literature, and a connection between it, a linear velocity profile, and a uniform specific internal energy profile has been identified. In this work, we assume the linear velocity profile to construct an entire class of self-similar sol utions in both cylindrical and spherical geometry, of which the Gaussian form is one possible member. After completing the derivation, we present some results in the context of a test problem for compressible flow codes.

Ramsey, Scott D [Los Alamos National Laboratory; Brown, Lowell S [Los Alamos National Laboratory; Nelson, Eric M [Los Alamos National Laboratory; Alme, Marv L [Los Alamos National Laboratory

2010-12-08T23:59:59.000Z

377

Hydrodynamics and High-Energy Physics of WR Colliding Winds  

E-Print Network (OSTI)

One of the main properties of Wolf-Rayet (WR) stars is a very intense outflow of gas. No less than 40\\% \\ of WR stars belong to binary systems. Young massive O and B stars are the secondary components of such systems. OB stars also have an intense stellar wind. If the intensities of the stellar winds of WR and OB stars are more or less comparable or if the distance between the components of the binary is large enough, the winds flowing out of WR and OB stars can collide and the shock waves are formed. In the shock the gas is heated to temperature $\\sim 10^7$ K and generates X-ray emission. Stellar wind collision may be responsible not only for the X-ray emission of WR + OB binaries and for their radio, IR and $\\gamma$-ray emision as well. Stellar wind collision, gas heating, particle acceleration, and generation of X-ray, $\\gamma$-ray, radio and IR emission in WR + OB binaries are discussed.

Vladimir V. Usov

1994-05-29T23:59:59.000Z

378

A smoothed particle hydrodynamics-based fluid model with a ...  

Science Conference Proceedings (OSTI)

... B.-W. Chun Grace Construction Products, Cambridge, MA 02140 ... use the derivative of a product property and ... to the testing of the fission hypotheses. ...

2011-03-27T23:59:59.000Z

379

Forced oscillations in a hydrodynamical accretion disk and QPOs  

E-Print Network (OSTI)

This is the second of a series of papers aimed to look for an explanation on the generation of high frequency quasi-periodic oscillations (QPOs) in accretion disks around neutron star, black hole, and white dwarf binaries. The model is inspired by the general idea of a resonance mechanism in the accretion disk oscillations as was already pointed out by Abramowicz & Klu{\\'z}niak (\\cite{Abramowicz2001}). In a first paper (P\\'etri \\cite{Petri2005a}, paper I), we showed that a rotating misaligned magnetic field of a neutron star gives rise to some resonances close to the inner edge of the accretion disk. In this second paper, we suggest that this process does also exist for an asymmetry in the gravitational potential of the compact object. We prove that the same physics applies, at least in the linear stage of the response to the disturbance in the system. This kind of asymmetry is well suited for neutron stars or white dwarfs possessing an inhomogeneous interior allowing for a deviation from a perfectly spherically symmetric gravitational field. We show by a linear analysis that the disk initially in a cylindrically symmetric stationary state is subject to three kinds of resonances: a corotation resonance, a Lindblad resonance due to a driven force and a parametric sonance. The highest kHz QPOs are then interpreted as the orbital frequency of the disk at locations where the response to the resonances are maximal. It is also found that strong gravity is not required to excite the resonances.

J. Petri

2005-09-22T23:59:59.000Z

380

Hydrogeology and hydrodynamics of coral reef pore waters  

DOE Green Energy (OSTI)

A wide variety of forces can produce head gradients that drive the flow and advective mixing of internal coral reef pore waters. Oscillatory gradients that produce mixing result from wave and tide action. Sustained gradients result from wave and tide-induced setup and ponding, from currents impinging on the reef structure, from groundwater heads, and from density differenced (temperature or salinity gradients). These gradients and the permeabilities and porosities of reef sediments are such that most macropore environments are dominated by advection rather than diffusion. The various driving forces must be analyzed to determine the individual and combined magnitudes of their effects on a specific reef pore-water system. Pore-water movement controls sediment diagenesis, the exchange of nutrients between sediments and benthos, and coastal/island groundwater resources. Because of the complexity of forcing functions, their interactions with specific local reef environments, experimental studies require careful incorporation of these considerations into their design and interpretation. 8 refs., 3 figs., 1 tab.

Buddemeier, R.W.; Oberdorfer, J.A.

1988-06-29T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Hydrodynamical interpretation of quantum mechanics: the momentum distribution  

E-Print Network (OSTI)

The quantum mechanics is considered to be a partial case of the stochastic system dynamics. It is shown that the wave function describes the state of statistically averaged system $$, but not that of the individual stochastic system $\\mathcal{S}_{st}$. It is a common practice to think that such a construction of quantum mechanics contains hidden variables, and it is incompatible with the von Neumann's theorem on hidden variables. It is shown that the original conditions of the von Neumann's theorem are not satisfied. In particular, the quantum mechanics cannot describe the particle momentum distribution. The distribution $w(\\mathbf{p}) =| \\psi_{p%}| ^{2}$ is not a particle momentum distribution at the state $\\psi $, because it cannot be attributed to a wave function. It is closer to the mean momentum distribution, although the two distributions do not coincide exactly.

Yuri A. Rylov

2004-02-15T23:59:59.000Z

382

On Freeze-Out Problem in Relativistic Hydrodynamics*  

Science Conference Proceedings (OSTI)

approach does not conserve energy and proposed their own recipe of the ..... The hydro calculation runs absolutely unrestricted. The freeze- out hypersurface is ...

383

Experimental validation of a radiographic simulation code using breast phantom for X-ray imaging  

Science Conference Proceedings (OSTI)

Computer models and simulations of X-ray imaging systems are becoming a very precious tool during the development and evaluation of new X-ray imaging techniques. To provide, however, a faithful simulation of a system, all components must be accurately ... Keywords: Breast phantoms, Experimental verification, Synchrotron radiation, X-ray imaging simulation

K. Bliznakova; R. Speller; J. Horrocks; P. Liaparinos; Z. Kolitsi; N. Pallikarakis

2010-02-01T23:59:59.000Z

384

Fractures of the Sacrum After Chemoradiation for Rectal Carcinoma: Incidence, Risk Factors, and Radiographic Evaluation  

Science Conference Proceedings (OSTI)

Purpose: Sacral insufficiency fractures after adjuvant radiation for rectal carcinoma can present similarly to recurrent disease. As a complication associated with pelvic radiation, it is important to be aware of the incidence and risk factors associated with sacral fractures in the clinical assessment of these patients. Methods and Materials: Between 1998 and 2007, a total of 582 patients with locally advanced rectal carcinoma received adjuvant chemoradiation and surgical excision. Of these, 492 patients had imaging studies available for review. Hospital records and imaging studies from all 492 patients were retrospectively evaluated to identify risk factors associated with developing a sacral insufficiency fracture. Results: With a median follow-up time of 3.5 years, the incidence of sacral fractures was 7.1% (35/492). The 4-year sacral fracture free rate was 0.91. Univariate analysis showed that increasing age ({>=}60 vs. =}60 vs. <60 years, hazard ratio [HR] = 2.50, 95% confidence interval [CI] = 1.22-5.13, P=.01), female sex (HR = 2.64, CI = 1.29-5.38, P=.008), and history of osteoporosis (HR = 3.23, CI = 1.23-8.50, P=.02) were independent risk factors associated with sacral fracture. Conclusions: Sacral insufficiency fractures after pelvic radiation for rectal carcinoma occur more commonly than previously described. Independent risk factors associated with fracture were osteoporosis, female sex, and age greater than 60 years.

Kim, Han Jo [Department of Orthopedic Surgery, Washington University, St. Louis, Missouri (United States)] [Department of Orthopedic Surgery, Washington University, St. Louis, Missouri (United States); Boland, Patrick J. [Department of Surgery, Orthopaedic Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Surgery, Orthopaedic Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Meredith, Dennis S. [Hospital for Special Surgery, Department of Orthopaedic Surgery, New York, New York (United States)] [Hospital for Special Surgery, Department of Orthopaedic Surgery, New York, New York (United States); Lis, Eric [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang Zhigang; Shi Weiji [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yamada, Yoshiya J. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-11-01T23:59:59.000Z

385

Optimization of X-ray Radiographic Imaging Birsen Yazici, Il-Young Son, An Jin  

E-Print Network (OSTI)

- Energy Storage and Organic Photovoltaic Devices - Next-Generation Organic Materials and Device after July 14, 2010. Accommodations Hotels Many comfortable hotels with easy access to the conference venue are located along with the subway lines in Kyoto City. Blocks of rooms at the following hotels

Yazici, Birsen

386

Reimbursement for Emergency Department Electrocardiography and Radiograph Interpretations: What Is It Worth for the Emergency Physician  

E-Print Network (OSTI)

262:3444-7. 21. Office of Inspector General, Department ofwas conducted by the Office of Inspector General (OIG), a

Wu, Tina; Bell, Mark R.; Blakeman, James R.; Edwards, Irv; Mallon, William K.

2009-01-01T23:59:59.000Z

387

Radiographic and Histologic Response to Neoadjuvant Radiotherapy in Patients With Soft Tissue Sarcoma  

E-Print Network (OSTI)

Medical Center, Sacramento, CA; 2 Division of OrthopedicDavis Medical Center, Sacramento, CA; 3 Department ofMedical Center, Sacramento, CA; 4 Division of Biostatistics,

2010-01-01T23:59:59.000Z

388

Rf phase measurement at PHERMEX (Pulsed High Energy Radiographic Machine Emitting X-Rays) using time-to-digital converters  

Science Conference Proceedings (OSTI)

Recent advances in time-to-digital converters (TDCs) have made 50-MHz rf phase measurement possible without the use of double-balanced mixers. These advances allow zero crossing discriminators to be used in conjunction with fast CAMAC TDCs to make amplitude-independent phase measurements. This method uses a time interval proportional to the phase angle, thus eliminating any of the calculations and calibration required with double-balanced mixers. 4 refs., 1 fig., 1 tab.

Watson, S.A.; Jennings, G.R.; Moir, D.C.

1989-01-01T23:59:59.000Z

389

Bremsstrahlung {gamma}-ray generation by electrons from gas jets irradiated by laser pulses for radiographic testing  

Science Conference Proceedings (OSTI)

Electron generation from a gas jet irradiated by low energy femtosecond laser pulses is studied experimentally as a promising source of radiation for radioisotope-free {gamma}-ray imaging systems. The calculated yield of {gamma}-rays in the 0.5-2 MeV range, produced by low-average-power lasers and gas targets, exceeds the yields from solid tape targets up to 60 times. In addition, an effect of quasi-mono energetic electrons on {gamma}-ray imaging is also discussed.

Oishi, Yuji; Nayuki, Takuya; Zhidkov, Alexei; Fujii, Takashi; Nemoto, Koshichi [Central Research Institute of Electric Power Industry, Yokosuka, Kanagawa 240-0196 (Japan); Central Research Institute of Electric Power Industry, Yokosuka, Kanagawa 240-0196, Japan and Photon Pioneers Center in Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan); Central Research Institute of Electric Power Industry, Yokosuka, Kanagawa 240-0196 (Japan)

2012-07-11T23:59:59.000Z

390

A hybrid particle-continuum method for hydrodynamics of complex fluids  

E-Print Network (OSTI)

A previously-developed hybrid particle-continuum method [J. B. Bell, A. Garcia and S. A. Williams, SIAM Multiscale Modeling and Simulation, 6:1256-1280, 2008] is generalized to dense fluids and two and three dimensional flows. The scheme couples an explicit fluctuating compressible Navier-Stokes solver with the Isotropic Direct Simulation Monte Carlo (DSMC) particle method [A. Donev and A. L. Garcia and B. J. Alder, ArXiv preprint 0908.0510]. To achieve bidirectional dynamic coupling between the particle (microscale) and continuum (macroscale) regions, the continuum solver provides state-based boundary conditions to the particle subdomain, while the particle solver provides flux-based boundary conditions for the continuum subdomain. The equilibrium diffusive (Brownian) motion of a large spherical bead suspended in a particle fluid is examined, demonstrating that the hybrid method correctly reproduces the velocity autocorrelation function of the bead but only if thermal fluctuations are included in the continuum solver. Finally, the hybrid is applied to the well-known adiabatic piston problem and it is found that the hybrid correctly reproduces the slow non-equilibrium relaxation of the piston toward thermodynamic equilibrium but, again, only the continuum solver includes stochastic (white-noise) flux terms. These examples clearly demonstrate the need to include fluctuations in continuum solvers employed in hybrid multiscale methods.

A. Donev; J. B. Bell; A. L. Garcia; B. J. Alder

2009-10-20T23:59:59.000Z

391

BASIC STUDIES IN MAGNETO-HYDRODYNAMICS. Final Report, May 1, 1957 to October 31, 1961  

SciTech Connect

The research described was directed toward obtaining a basic understanding of magnetohydrodynamics. The initial studies led to three possible applications for magnetohydrodynamics which in turn led to three categories of research. The fir st application appeared in connection with the problem of high- aItitude, very high velocity flight. The second application was plasma propulsion. The third category was the production of a very high temperature collision-free plasma. (auth)

Patrick, R.M.

1961-10-01T23:59:59.000Z

392

Hydrodynamic Simulation of Circulation and Residence Time in Clifton Court Forebay  

E-Print Network (OSTI)

Estuary. Technical report no. HYDRO-IATR/95-45. Sacramento (and Simpson 1997) and hydro- dynamic modeling efforts (inside CCF from detailed hydro- dynamic modeling conducted

MacWilliams, Michael L.; Gross, Edward S.

2013-01-01T23:59:59.000Z

393

LA-LP 10-017 Licensable KIVA—Hydrodynamics Model for ...  

? culty in controlling the combustion process. Poorly controlled and incomplete combustion can cause higher levels of emissions and lower engine ef? ...

394

High Performance Computing for Stability Problems - Applications to Hydrodynamic Stability and Neutron Transport Criticality.  

E-Print Network (OSTI)

??In this work we examine two kinds of applications in terms of stability and perform numerical evaluations and benchmarks on parallel platforms. We consider the… (more)

Subramanian, Chandramowli

2011-01-01T23:59:59.000Z

395

Multi-physics coupling of Einstein and hydrodynamics evolution: a case study of the Einstein toolkit  

Science Conference Proceedings (OSTI)

Cactus is a software framework for high-performance computing which sees widespread use in the numerical relativity community and other fields. The Einstein Toolkit is a set of Cactus components providing infrastructure and basic functionality for, and ...

Erik Schnetter

2008-10-01T23:59:59.000Z

396

AN INTEGRATED HYDRODYNAMIC / PVT VERTICAL WELLBORE MODEL FOR TWO-PHASE NATURAL GAS / LIQUID SYSTEMS.  

E-Print Network (OSTI)

??Multiphase flow in the wellbore poses a challenge for production engineers since characterization of prevailing flow regime determines the appropriate pressure drop calculation method. The… (more)

Sadegh, Abdallah

2006-01-01T23:59:59.000Z

397

TMDL Albuquerque, NM, 2003 Thaxton & McLaughlin HYDRODYNAMIC AND SEDIMENT CAPTURE ASSESSMENT  

E-Print Network (OSTI)

to the ratio of pond capacity and the average annual rainfall from the source watershed. Previous work has been Professor, Department of Soil Science, North Carolina State University, Raleigh, NC. Corresponding author sediment basin due to the installation of baffles composed of different materials commonly used

Thaxton, Christopher S.

398

Direct numerical simulations and hydrodynamic stability problems in the upper oceanic mixed layer  

Science Conference Proceedings (OSTI)

Langmuir circulations are longitudinal rolls driven by the wind and appear beneath the surface of the ocean. The author models these as an instability of the mean current due to its interaction with averaged effect of the surface waves. Perturbations are allowed for in three dimensions for a layer of finite depth. Linear stability analysis shows that two-dimensional rolls are most unstable for unstratified flow as in previous two-dimensional studies. In presence of stratification three-dimensional modes are most unstable. At low and high values of the Reynolds number, the most unstable modes are nearly two-dimensional. At intermediate values, three dimensionality is important. The angular deviation from the wind direction of the most unstable modes increases with stratification in the range considered. Two-dimensional simulations are done at different values of stratification for unconstrained and constrained sidewall boundary conditions. These show good agreement qualitatively and quantitatively with the weakly nonlinear dynamics of the governing equations in two-dimensions. A secondary stability (Floquet) analysis is performed to determine the range of stability of unstratified steady Langmuir rolls and elicit the streamwise length scales when rolls become unstable. Eckhaus and Oscillatory mechanisms of instability are found to be important at a moderate value of Reynolds number. Subsequent direct numerical simulations are performed for corresponding instabilities. Oscillatory instability sets in as streamwise traveling waves. As one of the destabilizing parameters is increased, quasi-periodic motion is observed, with a low frequency vacillating mode. At lower values of Reynolds number, the secondary instability thresholds for the forcing are higher and steady rolls are stable in a large domain of parameter space. Simulations at high forcing at low Reynolds number show defect traveling wave solutions.

Tandon, A.

1992-01-01T23:59:59.000Z

399

Hydrodynamic Studies in a Centrifugal Contactor Separator; Liquid Hold-up, Residence Time Distribution, Phase  

E-Print Network (OSTI)

Liquid-Liquid Extraction in Centrifugal Contactor Separators Boelo Schuur, Joelle Floure, Andy Hallett centrifugal contactor separator; process intensification; enantioselectivity; 3,5-dinitrobenzoyl alkaloid extractant (C) in 1,2- dichloroethane using a Centrifugal Contact Separator (CCS) was studied

Groningen, Rijksuniversiteit

400

Transport coefficients of causal dissipative relativistic hydrodynamics in quenched lattice simulations  

E-Print Network (OSTI)

Transport coefficients of causal dissipative relativistic fluid dynamics (CDR) are studied in quenched lattice simulations. CDR describes the behavior of relativistic non-Newtonian fluids in which the relaxation time appears as a new transport coefficient besides the shear and bulk viscosities. It was recently shown that these coefficients can be given by the temporal-correlation functions of the energy-momentum tensors as in the case of the Green-Kubo-Nakano formula. By using the new formula in CDR, we study the transport coefficients with lattice simulations in pure SU(3) gauge theory. After defining the energy-momentum tensor on the lattice, we extract a ratio of the shear viscosity to the relaxation time which is given only in terms of the static correlation functions. The simulations are performed on $24^3 \\times 4$--16 lattices with $\\beta_{_{\\rm LAT}} = 6.0$, which corresponds to the temperature range of $0.5 \\simle T/T_c \\simle 1.8$, where $T_c$ is the critical temperature.

Yu Maezawa; Hiroaki Abuki; Tetsuo Hatsuda; Tomoi Koide

2010-12-10T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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.


401

Soil Moisture Feedbacks on Convection Triggers: The Role of Soil–Plant Hydrodynamics  

Science Conference Proceedings (OSTI)

The linkages between soil moisture dynamics and convection triggers, defined here as the first crossing between the boundary layer height (hBL) and lifting condensation level (hLCL), are complicated by a large number of interacting processes ...

Mario Siqueira; Gabriel Katul; Amilcare Porporato

2009-02-01T23:59:59.000Z

402

Circulating fluidized bed hydrodynamics experiments for the multiphase fluid dynamics research consortium (MFDRC).  

Science Conference Proceedings (OSTI)

An experimental program was conducted to study the multiphase gas-solid flow in a pilot-scale circulating fluidized bed (CFB). This report describes the CFB experimental facility assembled for this program, the diagnostics developed and/or applied to make measurements in the riser section of the CFB, and the data acquired for several different flow conditions. Primary data acquired included pressures around the flow loop and solids loadings at selected locations in the riser. Tomographic techniques using gamma radiation and electrical capacitance were used to determine radial profiles of solids volume fraction in the riser, and axial profiles of the integrated solids volume fraction were produced. Computer Aided Radioactive Particle Tracking was used to measure solids velocities, fluxes, and residence time distributions. In addition, a series of computational fluid dynamics simulations was performed using the commercial code Arenaflow{trademark}.

Oelfke, John Barry; Torczynski, John Robert; O'Hern, Timothy John; Tortora, Paul Richard; Bhusarapu, Satish (; ); Trujillo, Steven Mathew

2006-08-01T23:59:59.000Z

403

Effects of hydrodynamic coefficients on the global motion characteristics of spar structures  

E-Print Network (OSTI)

A number of studies have already discussed the influence of various nonlinear effects on the response of a spar and the variation of the results with different approaches. In this work, the effects of the values of the inertia and drag coefficients used in Morison's equation on the response of a spar are studied in order to assess the sensitivity of the results to the assumed values of C[] and C[]. Two different programs, NDASPAR and SPARTCOM, developed independently at the Offshore Technology Research Center (OTRC), have been used for the study of the dynamic response due to excitation by two bichromatic waves, denoted as BC5 and BC8. Comparisons have been made between the experimental results obtained at the wave basin of the OTRC, results published originally by the respective authors of the two programs and the results obtained in this work. The quantities selected for comparison were mean offsets and maximum and minimum responses from the computed time histories of the surge and pitch motions, as well as the peaks of the frequency amplitude spectra (FAS) of these motions, representing the frequency content of the motions and allowing us to distinguish between linear and nonlinear components. The studies show that both programs give results which are in reasonable agreement with the experimental data as far as maximum (and minimum) response values are concerned and also show some significant differences in their frequency content and the amplitudes of the nonlinear peaks in the FAS of the motions. It was found that SPARTCOM reproduces the mean offset values much better, whereas the available version of NDASPAR does not account for mean drift effects. The study also shows that the value of the C[] primarily affects the amplitudes of the peaks at the natural frequencies while C[] affects the amplitude of the peak at the difference-frequency, as well as the natural frequencies. The two programs assume that changing the value of C[] also changes the added mass and therefore results in a change in the natural frequencies.

Sarkar, Indranil

2001-01-01T23:59:59.000Z

404

Nonclassical hydrodynamic behavior of Sn plasma irradiated with a long duration CO2 laser pulse  

E-Print Network (OSTI)

with a long duration CO 2 laser pulse Y. Tao · M.S. Tillackwith a long duration CO 2 laser pulse is much shorter thanmass and makes a CO 2 -laser-produced Sn plasma suitable as

Tao, Y.; Tillack, M. S.; Yuseph, S.; Burdt, R.; Najmabadi, F.

2010-01-01T23:59:59.000Z

405

AdS/CFT Correspondence and Hydrodynamics of Relativistic Heavy Ion Collisions.  

E-Print Network (OSTI)

??The experiments performed at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab have discovered a state of matter called the strongly coupled quark-gluon… (more)

Alsup, James Ethan

2010-01-01T23:59:59.000Z

406

Hydrodynamic causes and effects of air bubbles rising in very viscous media  

E-Print Network (OSTI)

Detailed understanding of two-phase gas liquid flows is imperative for developing efficient multi-phase reactors through precise control of mixing and reaction kinetics. The bubble column is a good apparatus for elementary studies of such flows. In the current study experiments are conducted to assess the effect of liquid viscosity on flow dynamics inside a bubble column. Corn oil and water are used as the continuous media, and air was the dispersed media. The objective of this effort is to use the results for a qualitative validation of the numerical simulations.

Ravinuthala, Sharad Chand

2013-01-01T23:59:59.000Z

407

Gaseous Laser Targets and Optical Dignostics for Studying Compressible Turbulent Hydrodynamic Instabilities  

Science Conference Proceedings (OSTI)

The possibility of studying compressible turbulent flows using gas targets driven by high power lasers and diagnosed with optical techniques is investigated. The potential advantage over typical laser experiments that use solid targets and x-ray diagnostics is more detailed information over a larger range of spatial scales. An experimental system is described to study shock - jet interactions at high Mach number. This consists of a mini-chamber full of nitrogen at a pressure {approx} 1 atms. The mini-chamber is situated inside a much larger vacuum chamber. An intense laser pulse ({approx}100J in {approx} 5ns) is focused on to a thin {approx} 0.3{micro}m thick silicon nitride window at one end of the mini-chamber. The window acts both as a vacuum barrier, and laser entrance hole. The ''explosion'' caused by the deposition of the laser energy just inside the window drives a strong blast wave out into the nitrogen atmosphere. The spherical shock expands and interacts with a jet of xenon introduced though the top of the mini-chamber. The Mach number of the interaction is controlled by the separation of the jet from the explosion. The resulting flow is visualized using an optical schlieren system using a pulsed laser source at a wavelength of 0.53 {micro}m. The technical path leading up to the design of this experiment is presented, and future prospects briefly considered. Lack of laser time in the final year of the project severely limited experimental results obtained using the new apparatus.

Edwards, M J; Hansen, J; Miles, A R; Froula, D; Gregori, G; Glenzer, S; Edens, A; Dittmire, T

2005-02-08T23:59:59.000Z

408

Hydrodynamical simulations of the SunyaevZel'dovich effect: the kinetic effect  

E-Print Network (OSTI)

to be in massive haloes. A detailed analytical model has recently been constructed by Valageas, Balbi & Silk (2001

Thomas, Peter

409

Influence of hydrodynamics on the larval supply to hydrothermal vents on the East Pacific Rise  

E-Print Network (OSTI)

Examination of the scales at which larval supply varies spatially and temporally, and correlation with concurrent physical observations can provide insights into larval transport mechanisms that contribute to structuring ...

Adams, Diane K. (Diane Kirsten)

2007-01-01T23:59:59.000Z

410

Petascale Algorithms for Reactor Hydrodynamics Paul Fischer, James Lottes, David Pointer, and Andew Siegel  

E-Print Network (OSTI)

to P = 65, 000 processors on the IBM BG/P at the Argonne Leadership Computing Facility. 1. Introduction-AC02-06CH11357. Computer time on the Argonne Leadership Computing Facility was provided through a 2008 cores. The aim is to leverage petascale platforms at DOE's Leadership Computing Figure 1. Turbulence

Fischer, Paul F.

411

Hydrodynamic Optimisation of point wave-energy converter using laboratory experiments.  

E-Print Network (OSTI)

??Investment in renewable energy technology, such as wave power, is increasingly seen as a beneficial and economically-viable alternative to existing fossil-based power plants. New Zealand… (more)

Kelly, Scott John

412

Self-Organized Hydrodynamics with congestion and path formation in crowds  

E-Print Network (OSTI)

A continuum model for self-organized dynamics is numerically investigated. The model describes systems of particles subject to alignment interaction and short-range repulsion. It consists of a non-conservative hyperbolic system for the density and velocity orientation. Short-range repulsion is included through a singular pressure which becomes infinite at the jamming density. The singular limit of infinite pressure stiffness leads to phase transitions from compressible to incompressible dynamics. The paper proposes an Asymptotic-Preserving scheme which takes care of the singular pressure while preventing the breakdown of the CFL stability condition near congestion. It relies on a relaxation approximation of the system and an elliptic formulation of the pressure equation. Numerical simulations of impinging clusters show the efficiency of the scheme to treat congestions. A two-fluid variant of the model provides a model of path formation in crowds.

Pierre Degond; Jiale Hua

2012-07-15T23:59:59.000Z

413

COMPARISON OF SPECTRAL SLOPES OF MAGNETOHYDRODYNAMIC AND HYDRODYNAMIC TURBULENCE AND MEASUREMENTS OF ALIGNMENT EFFECTS  

Science Conference Proceedings (OSTI)

We performed a series of high-resolution (up to 1024{sup 3}) direct numerical simulations of hydro and magnetohydrodynamic (MHD) turbulence. Our simulations correspond to the 'strong' MHD turbulence regime that cannot be treated perturbatively. We found that for simulations with normal viscosity the slopes for energy spectra of MHD are similar to ones in hydro, although slightly more shallower. However, for simulations with hyperviscosity the slopes were very different, for instance, the slopes for hydro simulations showed a pronounced and well defined bottleneck effect, while the MHD slopes were relatively much less affected. We believe that this is indicative of MHD strong turbulence being less local than the Kolmogorov turbulence. This calls for revision of MHD strong turbulence models that assume local 'as-in-hydro case' cascading. Nonlocality of MHD turbulence casts doubt on numerical determination of the slopes with currently available (512{sup 3}-1024{sup 3}) numerical resolutions, including simulations with normal viscosity. We also measure various so-called alignment effects and discuss their influence on the turbulent cascade.

Beresnyak, A.; Lazarian, A. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)], E-mail: andrey@astro.wisc.edu, E-mail: lazarian@astro.wisc.edu

2009-09-10T23:59:59.000Z

414

Merger of white dwarf-neutron star binaries: Prelude to hydrodynamic simulations in general relativity  

E-Print Network (OSTI)

White dwarf-neutron star binaries generate detectable gravitational radiation. We construct Newtonian equilibrium models of corotational white dwarf-neutron star (WDNS) binaries in circular orbit and find that these models terminate at the Roche limit. At this point the binary will undergo either stable mass transfer (SMT) and evolve on a secular time scale, or unstable mass transfer (UMT), which results in the tidal disruption of the WD. The path a given binary will follow depends primarily on its mass ratio. We analyze the fate of known WDNS binaries and use population synthesis results to estimate the number of LISA-resolved galactic binaries that will undergo either SMT or UMT. We model the quasistationary SMT epoch by solving a set of simple ordinary differential equations and compute the corresponding gravitational waveforms. Finally, we discuss in general terms the possible fate of binaries that undergo UMT and construct approximate Newtonian equilibrium configurations of merged WDNS remnants. We use these configurations to assess plausible outcomes of our future, fully relativistic simulations of these systems. If sufficient WD debris lands on the NS, the remnant may collapse, whereby the gravitational waves from the inspiral, merger, and collapse phases will sweep from LISA through LIGO frequency bands. If the debris forms a disk about the NS, it may fragment and form planets.

Vasileios Paschalidis; Morgan MacLeod; Thomas W. Baumgarte; Stuart L. Shapiro

2009-10-29T23:59:59.000Z

415

Spatio-temporal evolution and breaking of double layers: A description using Lagrangian hydrodynamics  

Science Conference Proceedings (OSTI)

The nonlinear development and collapse (breaking) of double layers in the long scale length limit is well described by equations for the cold ion fluid with quasineutrality. It is shown that electron dynamics is responsible for giving an 'equation of state' with negative ratio of specific heats to this fluid. Introducing a transformation for the density variable, the governing equation for the transformed quantity in terms of Lagrange variables turns out exactly to be a linear partial differential equation. This equation has been analyzed in various limits of interest. Nonlinear development of double layers with a sinusoidal initial disturbance and collapse of double layers with an initial perturbation in the form of a density void are analytically investigated.

Kaw, Predhiman; Sengupta, Sudip; Singh Verma, Prabal [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2012-10-15T23:59:59.000Z

416

The First Five Minutes of a Core Collapse Supernova: Multidimensional Hydrodynamic Models  

E-Print Network (OSTI)

We present results of high-resolution two-dimensional simulations which follow the first five minutes of a core collapse supernova explosion in a 15 solar mass blue supergiant progenitor. The computations start shortly after core bounce and include neutrino-matter interactions by using a light-bulb approximation for the neutrinos, and a treatment of the nucleosynthesis due to explosive silicon and oxygen burning. We find that newly formed iron-group elements are distributed throughout a significant fraction of the stellar helium core by the concerted action of convective and Rayleigh-Taylor instabilities. Fast moving nickel mushrooms with velocities up to 4000 km/s are observed. A continuation of the calculations to later times, however, indicates, that the iron velocities observed in SN 1987 A cannot be reproduced due to a strong deceleration of the clumps during their interaction with the dense shell left behind by the shock at the He/H interface. Therefore, we cannot confirm the claim that convective "premixing" of the nickel in the early phases of the explosion solves the problem of the high iron velocities.

K. Kifonidis; T. Plewa; H. -Th. Janka; E. Mueller

1999-11-22T23:59:59.000Z

417

An efficient immersed boundary-lattice Boltzmann method for the hydrodynamic interaction of elastic filaments  

E-Print Network (OSTI)

these problems typically requires coupling fluid dynam- ics and structural mechanics and solving the two of a stationary bluff body may harness the kinetic energy from the vortices generated by the body [47 in which the stress exerted by the structure on the fluid is spread onto the collocated grid points near

Liao, James C.

418

Effects of hydrodynamic film boundary conditions on bubble-wall impact  

E-Print Network (OSTI)

: Manica, Rogerio; Institute of High Performance Computing, Fluid Dynamics Hendrix, Maurice; University of Twente, Gupta, Raghvendra; Institute of High Performance Computing, Fluid Dynamics Klaseboer, Evert; Institute of High Performance Computing, Fluid Dynamics Ohl, Claus-Dieter; Nanyang Technological University

Chan, Derek Y C

419

A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs  

E-Print Network (OSTI)

diffusion of a tracer or a radionuclide. This new module ofsimulate processes of tracer/radionuclide transport using ana) a tracer or a radionuclide is present and transported

Wu, Yu-Shu; Pruess, Karsten

1998-01-01T23:59:59.000Z

420

Hydrodynamics at RHIC -- how well does it work, where and how does it break down?  

E-Print Network (OSTI)

I review the successes and limitations of the ideal fluid dynamic model in describing hadron emission spectra from Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC).

Ulrich W. Heinz

2004-12-24T23:59:59.000Z

Note: This page contains sample records for the topic "dual-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

Growth impact of hydrodynamic dispersion in a Couette-Taylor bioreactor  

Science Conference Proceedings (OSTI)

The development of a distributed parameter model of microalgae growth is presented. Two modelling frameworks for photo-bioreactor modelling, Eulerian and Lagrangian, are discussed and the complications residing in the multi-scale nature of transport ... Keywords: Boundary value problem, Distributed parameter system, Multi-scale modelling, Photosynthetic factory, Random walk

ŠTpáN Papá?Ek; VáClav ŠTumbauer; Dalibor ŠTys; Karel Petera; Ctirad Matonoha

2011-10-01T23:59:59.000Z

422

Hydrodynamic Modeling for Autonomous Underwater Vehicles Using Computational and Semi-Empirical Methods.  

E-Print Network (OSTI)

??Buoyancy driven underwater gliders, which locomote by modulating their buoyancy and their attitude with moving mass actuators and inflatable bladders, are proving their worth as… (more)

Geisbert, Jesse Stuart

2007-01-01T23:59:59.000Z

423

Hydrodynamics of adiabatic inverted annular flow: an experimental study. [PWR; BWR  

SciTech Connect

For low-quality film boiling in tubes or rod bundles, the flow pattern may consist of a liquid jet-like core surrounded by a vapor annulus, i.e., inverted annular flow. The stability, shape, and break-up mechanisms of this liquid core must be understood in order to model correctly this regime and to develop appropriate interfacial transfer correlations. This paper reports on a study in which inverted annular flow was simulated in an adiabatic system. Turbulent water jets, issuing downward from long-aspect nozzles were enclosed within cocurrent gas annuli. Jet-core diameter and velocity, and gas-annulus diameter, velocity, and species were varied, yielding liquid Reynolds numbers up to 33,000, void fractions from 0.29 to 0.95, and relative velocities from near zero to over 80 m/s. Jet-core break-up lengths and secondarily, core break-up mechanisms, were observed visually, using strobe lighting.

De Jarlais, G.; Ishii, M.

1983-01-01T23:59:59.000Z

424

Theoretical studies in spiral edge-flame propagation and particle hydrodynamics  

E-Print Network (OSTI)

Diffusion-flame stand-off distance. . . . . . . . . .Summary of experimental flame patterns observed in theSpiral Edges of Diffusion Flames in Von K´ arm´ an Swirling

Urzay, Javier

2010-01-01T23:59:59.000Z

425

Evaluation of the New B-REX Fatigue Testing System for Multi-Megawatt Wind Turbine Blades: Preprint  

DOE Green Energy (OSTI)

The National Renewable Energy Laboratory (NREL) recently developed a new hybrid fatigue testing system called the Blade Resonance Excitation (B-REX) test system. The new system uses 65% less energy to test large wind turbine blades in half the time of NREL's dual-axis forced-displacement test method with lower equipment and operating costs. The B-REX is a dual-axis test system that combines resonance excitation with forced hydraulic loading to reduce the total test time required while representing the operating strains on the critical inboard blade stations more accurately than a single-axis test system. The analysis and testing required to fully implement the B-REX was significant. To control unanticipated blade motion and vibrations caused by dynamic coupling between the flap, lead-lag, and torsional directions, we needed to incorporate additional test hardware and control software. We evaluated the B-REX test system under stable operating conditions using a combination of various sensors. We then compared our results with results from the same blade, tested previously using NREL's dual-axis forced-displacement test method. Experimental results indicate that strain levels produced by the B-REX system accurately replicated the forced-displacement method. This paper describes the challenges we encountered while developing the new blade fatigue test system and the experimental results that validate its accuracy.

White, D.; Musial, W.; Engberg, S.

2004-12-01T23:59:59.000Z

426

Serum CA 19-9 as a Marker of Resectability and Survival in Patients with Potentially Resectable Pancreatic Cancer Treated with Neoadjuvant Chemoradiation  

E-Print Network (OSTI)

with radiographically occult disease progression. Thein whom radiographically occult advanced disease willbeen reported to signify occult disease that will prohibit

2010-01-01T23:59:59.000Z

427

Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling  

SciTech Connect

The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of work in section F.

Pannala, S.; D'Azevedo, E.; Zacharia, T.

2002-02-26T23:59:59.000Z

428

Hydrodynamics of high-redshift galaxy collisions: From gas-rich disks to dispersion-dominated mergers and compact spheroids  

E-Print Network (OSTI)

Disk galaxies at high redshift (z~2) are characterized by high fractions of cold gas, strong turbulence, and giant star-forming clumps. Major mergers should typically involve such galaxies. High-redshift merger simulations, however, have always modeled the ISM as stable, homogeneous, and thermally pressurized. We present the first high-redshift merger simulations with cold, turbulent, and clumpy gas, and we discuss the major new features of these models compared to models where the gas is artificially stabilized and warmed. Gas turbulence, which is already strong in high-redshift disks, is further enhanced in mergers. Some phases are dispersion-dominated, with most of the gas kinetic energy in the form of velocity dispersion and very chaotic velocity fields, unlike low-redshift mergers. High-redshift mergers are also characterized by highly dissipative gas collapse to the center of mass, with the stellar component following in a global contraction. The final galaxies are early-type with relatively small radii...

Bournaud, Frederic; Delaye, Lauriane; Powell, Leila C; Elmegreen, Bruce G; Elmegreen, Debra Meloy; Duc, Pierre-Alain; Teyssier, Romain; Contini, Thierry; Epinat, Benoit; Shapiro, Kristen L

2010-01-01T23:59:59.000Z

429

From Proceedings, BOSS-97: Behaviour of Offshore Structures Volume 2 (Hydrodynamics), ed. J.Vugts, Delft Univ, 1997, pp. 333347.  

E-Print Network (OSTI)

and at the University of Texas at Austin. This study compares analytical predictions of spar surge motions to first-order wave energy, a low-frequency contribution due to pitch, and a still lower frequency

Sweetman, Bert

430

Verification Test Suite (VERTS) For Rail Gun Applications using ALE3D: 2-D Hydrodynamics & Thermal Cases  

Science Conference Proceedings (OSTI)

A verification test suite has been assessed with primary focus on low reynolds number flow of liquid metals. This is representative of the interface between the armature and rail in gun applications. The computational multiphysics framework, ALE3D, is used. The main objective of the current study is to provide guidance and gain confidence in the results obtained with ALE3D. A verification test suite based on 2-D cases is proposed and includes the lid-driven cavity and the Couette flow are investigated. The hydro and thermal fields are assumed to be steady and laminar in nature. Results are compared with analytical solutions and previously published data. Mesh resolution studies are performed along with various models for the equation of state.

Najjar, F M; Solberg, J; White, D

2008-04-17T23:59:59.000Z

431

Modeling the Impacts of Pulsed Riverine Inflows on Hydrodynamics and Water Quality in the Barataria Bay Estuary.  

E-Print Network (OSTI)

??Eutrophication and coastal wetland loss are the major environmental problems affecting estuaries around the world. In Louisiana, controlled diversions of the Mississippi River water back… (more)

Das, Anindita

2010-01-01T23:59:59.000Z

432

THREE-DIMENSIONAL HYDRODYNAMICAL SIMULATIONS OF A PROTON INGESTION EPISODE IN A LOW-METALLICITY ASYMPTOTIC GIANT BRANCH STAR  

Science Conference Proceedings (OSTI)

We use the three-dimensional (3D) stellar structure code DJEHUTY to model the ingestion of protons into the intershell convection zone of a 1 M{sub Sun} asymptotic giant branch star of metallicity Z = 10{sup -4}. We have run two simulations: a low-resolution one of around 300,000 zones and a high-resolution one consisting of 2,000,000 zones. Both simulations have been evolved for about 4 hr of stellar time. We observe the existence of fast, downward flowing plumes that are able to transport hydrogen into close proximity to the helium-burning shell before burning takes place. The intershell in the 3D model is richer in protons than the 1D model by several orders of magnitude and so we obtain substantially higher hydrogen-burning luminosities-over 10{sup 8} L{sub Sun} in the high-resolution simulation-than are found in the 1D model. Convective velocities in these simulations are over ten times greater than the predictions of mixing length theory, though the 3D simulations have greater energy generation due to the enhanced hydrogen burning. We find no evidence of the convective zone splitting into two, though this could be as a result of insufficient spatial resolution or because the models have not been evolved for long enough. We suggest that the 1D mixing length theory and particularly the use of a diffusion algorithm for mixing do not give an accurate picture of these events. An advective mixing scheme may give a better representation of the transport processes seen in the 3D models.

Stancliffe, Richard J.; Lattanzio, John C.; Heap, Stuart A.; Campbell, Simon W. [Monash Centre for Astrophysics (formerly the Centre for Stellar and Planetary Astrophysics), Monash University, VIC 3800 (Australia); Dearborn, David S. P., E-mail: rjs@mso.anu.edu.au [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551 (United States)

2011-12-01T23:59:59.000Z

433

An experimental investigation of the hydrodynamic and heat-transfer behavior of aqueous foam in laminar tube flow  

DOE Green Energy (OSTI)

The structure of both static and dynamic aqueous foam samples has been observed photographically. Velocity profiles for a pipe-flow configuration were measured using a hot-film anemometer and an indirect calibration method. Temperature profiles at the end of a 3-m-long test section were measured using a thermocouple probe on a traversing mechanism. A finite-control-volume model of the energy equation for the flowing foam and the surrounding pipe was developed and compared with experimental results.

Blackwell, B.F.; Sobolik, K.B.

1987-12-01T23:59:59.000Z

434

Predicted macroinvertebrate response to water diversion from a montane stream using two-dimensional hydrodynamic models and zero flow approximation  

E-Print Network (OSTI)

E(S), expected number of species; LIDAR, light detection andobtained 1 m resolution LIDAR (Light Detection And Ranging)

Holmquist, Jeffrey G; Waddle, Terry J

2013-01-01T23:59:59.000Z

435

Incorporation of Reaction Kinetics into a Multiphase, Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor  

DOE Green Energy (OSTI)

This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different i