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1

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...

2

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.

3

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 theDual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL)...

4

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

5

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

6

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

7

Report of independent consultants reviewing Integrated Test Stands (ITS) performance and readiness of DARHT for construction start  

SciTech Connect

Independent consultants met at Los Alamos, June 15 and 16, 1993, to review progress on the commissioning of the Integrated Test Stand (ITS) for DARHT and to provide DOE with technical input on readiness for construction of the first radiographic arm of DARHT. The consultants concluded that all milestones necessary for demonstrating the performance of the DARHT accelerator have been met and that the project is ready for construction to resume. The experimental program using ITS should be continued to quantify the comparison of experiment and theory, to test improvements on the injector insulator, and to better evaluate the interaction of the beam and the target.

Not Available

1993-08-01T23:59:59.000Z

8

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

9

NNSA, LANL Complete DARHT Improvements With Successful Multi-frame  

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

LANL Complete DARHT Improvements With Successful Multi-frame LANL Complete DARHT Improvements With Successful Multi-frame Hydrodynamic Test | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > Media Room > Press Releases > NNSA, LANL Complete DARHT Improvements With Successful ... Press Release NNSA, LANL Complete DARHT Improvements With Successful Multi-frame

10

Nuclear stockpile stewardship and Bayesian image analysis (DARHT and the BIE)  

SciTech Connect

Since the end of nuclear testing, the reliability of our nation's nuclear weapon stockpile has been performed using sub-critical hydrodynamic testing. These tests involve some pretty 'extreme' radiography. We will be discussing the challenges and solutions to these problems provided by DARHT (the world's premiere hydrodynamic testing facility) and the BIE or Bayesian Inference Engine (a powerful radiography analysis software tool). We will discuss the application of Bayesian image analysis techniques to this important and difficult problem.

Carroll, James L [Los Alamos National Laboratory

2011-01-11T23:59:59.000Z

11

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

12

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...

13

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

14

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

15

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

16

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...

17

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

18

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...

19

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

20

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

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

22

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 +

23

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...

24

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

25

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

26

Calibrating the DARHT Electron Spectrometer with Negative Ions  

DOE Green Energy (OSTI)

Negative ions of hydrogen and oxygen have been used to calibrate the DARHT electron spectrometer over the momentum range of 2 to 20 MeV/c. The calibration was performed on September 1, 3, and 8, 2004, and it is good to 0.5% absolute, provided that instrument alignment is carefully controlled. The momentum in MeV/c as a function of magnetic field (B in Gauss) and position in the detector plane (X in mm) is: P = (B-6.28)/(108.404-0.1935*X)

R. Trainham (STL), A. P. Tipton (LAO), and R. R. Bartech (LANL)

2005-11-01T23:59:59.000Z

27

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

28

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...

29

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

30

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

31

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

32

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

33

Reliability and Lifetime Testing of the DARHT Second Axis Induction Cells  

E-Print Network (OSTI)

pulse duration requirement. The higher voltages were definedrequirement of the cells has also been achieved. Without any scaling for increased voltage,

Waldron, W.L.; Nielsen, K.E.; Spence, P.W.

2005-01-01T23:59:59.000Z

34

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

35

Careers  

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

Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory 100 Tesla Multi-shot Magnet - 1 100 Tesla Multi-shot Magnet - 1 Member of the SQUID team, with...

36

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

37

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

38

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

39

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

40

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

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41

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":""}]}

42

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":""}]}

43

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":""}]}

44

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":""}]}

45

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":""}]}

46

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":""}]}

47

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":""}]}

48

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":""}]}

49

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

50

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

51

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

52

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

53

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

54

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":""}]}

55

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

56

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

57

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

58

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":""}]}

59

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

60

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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.
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to obtain the most current and comprehensive results.


61

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

62

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

63

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

64

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

65

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

66

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

67

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

68

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

69

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

70

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

71

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

72

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

73

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

74

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

75

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

76

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 Cmpian

2011-04-01T23:59:59.000Z

77

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

78

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

79

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

80

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

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


81

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

82

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

83

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

84

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

85

TEST  

Science Conference Proceedings (OSTI)

This is an abstract. TEST Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras lacinia dui et est venenatis lacinia. Vestibulum lacus dolor, adipiscing id mattis sit amet, ultricies sed purus. Nulla consectetur aliquet feugiat. Maecenas ips

86

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.

87

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

88

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

89

Gas-liquid hydrodynamics in Taylor Flows with complex liquids.  

E-Print Network (OSTI)

??Universit di Pisa Facolt 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

90

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...

91

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...

92

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.

93

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

94

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

95

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

96

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

97

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

98

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

99

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

100

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

Note: This page contains sample records for the topic "hydrodynamic test darht" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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101

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

102

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

103

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

104

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

105

Category:Testing Facility Operators | Open Energy Information  

Open Energy Info (EERE)

Facility Operators Facility Operators Jump to: navigation, search This category contains facilities for research on renewable technologies and uses the form Testing Facility Operator. Pages in category "Testing Facility Operators" The following 26 pages are in this category, out of 26 total. A Alden Research Laboratory, Inc B Bucknell University C Colorado State University Hydrodynamics Cornell University Hydrodynamics M Massachusetts Institute of Technology Hydrodynamics O Ohmsett Oregon State University Hydrodynamics P Pennsylvania State University Hydrodynamics S Sandia National Laboratories Hydrodynamics S cont. Stevens Institute of Technology T Texas A&M (Haynes) Texas A&M (OTRC) U United States Army Corp of Engineers (ERDC) United States Geological Survey, HIF United States Geological Survey, LSC

106

NNSA's Summary of Experiments Conducted in Support of Stockpile...  

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

Test (DARHT) facility at Los Alamos National Laboratory, National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, and the Z machine at Sandia National...

107

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

108

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

109

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

110

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

111

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

112

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

113

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

114

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

115

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

116

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

117

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

118

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

119

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

120

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

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

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

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

125

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

126

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

127

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

128

Property:Testing Facilities Overseen | Open Energy Information  

Open Energy Info (EERE)

Testing Facilities Overseen Testing Facilities Overseen Jump to: navigation, search This is a property of type Page and uses the Testing Facility form Pages using the property "Testing Facilities Overseen" Showing 25 pages using this property. A Alden Research Laboratory, Inc + Alden Tow Tank +, Alden Wave Basin +, Alden Small Flume +, ... B Bucknell University + Bucknell Hydraulic Flume + C Cornell University Hydrodynamics + DeFrees Flume 1 +, DeFrees Flume 2 +, DeFrees Flume 3 +, ... M Massachusetts Institute of Technology Hydrodynamics + MIT Tow Tank + O Ohmsett + Ohmsett Tow Tank + Oregon State University Hydrodynamics + Hinsdale Wave Basin 1 +, Hinsdale Wave Basin 2 + P Pennsylvania State University Hydrodynamics + Penn Reverberant Tank +, Penn Small Water Tunnel +, Penn Large Water Tunnel +

129

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 Garz; Nagi Khalil

2013-10-02T23:59:59.000Z

130

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

131

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

132

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

133

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

134

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; Bjrn Buchle

2012-11-11T23:59:59.000Z

135

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

136

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

137

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

138

Tested by Fire - How two recent Wildfires affected Accelerator Operations at LANL  

SciTech Connect

In a little more than a decade two large wild fires threatened Los Alamos and impacted accelerator operations at LANL. In 2000 the Cerro Grande Fire destroyed hundreds of homes, as well as structures and equipment at the DARHT facility. The DARHT accelerators were safe in a fire-proof building. In 2011 the Las Conchas Fire burned about 630 square kilometers (250 square miles) and came dangerously close to Los Alamos/LANL. LANSCE accelerator operations Lessons Learned during Las Conchas fire: (1) Develop a plan to efficiently shut down the accelerator on short notice; (2) Establish clear lines of communication in emergency situations; and (3) Plan recovery and keep squirrels out.

Spickermann, Thomas [Los Alamos National Laboratory

2012-08-01T23:59:59.000Z

139

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

140

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

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. Chize; B. Dubroca

2002-06-17T23:59:59.000Z

142

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

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

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

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

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

156

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

157

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 Sead; Ioan Teleaga

2007-07-01T23:59:59.000Z

158

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

159

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

160

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

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

162

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. Vir; D. Krasnov; T. Boeck; B. Knaepen

2011-03-01T23:59:59.000Z

163

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, Jos M. Domnguez, Benedict D. Rogers, Alejandro J. C. Crespo

2013-11-01T23:59:59.000Z

164

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

165

DARHT-II Injector Transients and the Ferrite Damper  

E-Print Network (OSTI)

folding time constant ~ 0.8 usec 2.00E-06 2.50E-06 3.00E-06folding time constant ~ 0.25 usec 2.00E-06 2.50E-06 3.00E-06

M., Waldron, W.; Reginato, L.; Chow, K.; Houck. T.; Henestroza, E.; Yu, S.; Kang,

2008-01-01T23:59:59.000Z

166

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

167

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

168

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

169

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

170

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

171

Test Automation Test Automation  

E-Print Network (OSTI)

Test Automation Test Automation Mohammad Mousavi Eindhoven University of Technology, The Netherlands Software Testing 2013 Mousavi: Test Automation #12;Test Automation Outline Test Automation Mousavi: Test Automation #12;Test Automation Why? Challenges of Manual Testing Test-case design: Choosing inputs

Mousavi, Mohammad

172

Tidal Energy Test Platform | Open Energy Information  

Open Energy Info (EERE)

Test Platform Test Platform Jump to: navigation, search Basic Specifications Facility Name Tidal Energy Test Platform Overseeing Organization University of New Hampshire Hydrodynamics Hydrodynamic Testing Facility Type Offshore Berth Water Type Saltwater Cost(per day) Contact POC Special Physical Features The Tidal Testing Platform is presently a 10.7m long x 3m wide pontoon barge with a derrick and an opening for deploying tidal energy devices. The platform is intentionally configured to be adaptive for the changing needs of different devices. Towing Capabilities Towing Capabilities None Wavemaking Capabilities Wavemaking Capabilities None Channel/Tunnel/Flume Channel/Tunnel/Flume None Wind Capabilities Wind Capabilities None Control and Data Acquisition Cameras None

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

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

175

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

176

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

177

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

178

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

179

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

180

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...

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181

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

182

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

183

A Coupled HydrodynamicBottom 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

184

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

185

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

186

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

187

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

188

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

189

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

190

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

191

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

192

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

193

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 Stcker

2008-06-10T23:59:59.000Z

194

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

195

Comments on cathode contaminants and the LBNL test stand  

Science Conference Proceedings (OSTI)

This report collects information on cathode contaminants we have gathered in the process of operating the LBNL DARHT cathode test stand. Information on contaminants is compiled from several sources. The attachment, ''Practical Aspects of Modern Dispenser Cathodes'', is from Heat Wave Corp. (TB-134) and was originally published in Microwave Journal, September 1979. Cathode contamination depends on both material choices and residual gases. Table 1 of TB-134 lists materials that can poison dispenser cathodes. These include reactive residual gases or vapors such as oxygen, water vapor, benzene, chlorine, fluorine, sulfur, silicon, and most metals other than molybdenum, rhenium, tungsten, and copper. The metals interact with the cathode surface through their vapor pressure. A paper by Nexsen and Turner, J. Appl. Phys. 68, 298-303 (1990) shows the threshold effects of some common residual gases or vapors on cathode performance. The book by Walter H. Kohl, Handbook of Materials and Techniques for Vacuum Devices, also contains useful information on cathodes and poisoning agents. A plot of the vapor pressures and poisoning effect of certain metals (from Kohl) is shown below. Note that the vapor pressure of zinc is 1.1 x 10{sup -8} Torr at 400 K = 127 C, and 2.7 x 10{sup -5} at 500 K = 227 C. By contrast iron reaches a vapor pressure 1 x 10{sup -8} between 800 and 900 C. Therefore it is important to eliminate any brass parts that could exceed a temperature of 100 C. Many structural components of the cathode assembly contain steel. At 500-600 C in an oxygen atmosphere chromium oxide may outgas from the steel. [Cho, et.al., J. Vac. Sci. Technol. A 19, p. 998 (2001)]. Steel may also contain silicon, and sulfur at low concentrations. Therefore use of steel should be limited or avoided at high temperature near the cathode. Materials that should be avoided in the vicinity of the cathode include brass, silver, zinc, non-OFHC copper, silicates, and sulfur-containing lubricants such molybdenum disulfide. Macor is an aluminosilicate-based insulator that is not stable at high temperature. Macor near the cathode should be replaced by a high-temperature insulator such as alumina ceramic. Other insulating materials that contain silicates, such as fiber insulating sleeves, should be avoided. Copper that is not OFHC contains oxygen and other impurities and should be avoided. Lubricating screw coatings should be chosen carefully to have no sulfur content. Common sources of contamination that can cause low emission include water, saliva, silicates such as glass dust, etc. Cathodes should be handled in near clean-room conditions to minimize the amount of water vapor on the cathode surface from breathing, etc. Cathodes should also be stored in such as a way as to avoid contact with materials such as glass dust and water vapor. Attached are plots of SEM data for several test pieces that were taken from the LBNL test stand after activation of the 311x scandate DARHT cathode. Several copper pieces in the anode region were tested, showing the presence of zinc. Two stainless steel nuts coated with a contaminant were also tested. The SEM data indicates the presence of zinc and some sulfur. The zinc has been traced to a brass piece, and the sulfur to the possible use of molybdenum disulfide lubricant on a nut in the system. Finally a swipe of contaminant on the vacuum vessel wall analyzed by a commercial testing laboratory shows again the presence of zinc. In order to improve system cleanliness, we have implemented the following modifications to the test stand: replaced the brass piece with copper-tungsten; replaced Macor insulators with alumina ceramic; used boron nitride lubricant; replaced copper beam stop with OFHC copper; and replaced steel pieces near the cathode where possible with copper or copper-tungsten. A clean fire of high-temperature components and a high-current filament test have shown no evidence to date for contaminants since the modifications.

Bieniosek, F.; Baca, D.; Greenway, W.; Leitner, M.; Kwan, J.W.

2006-11-13T23:59:59.000Z

196

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

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

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

199

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

200

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

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While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

202

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...

203

The dispersive behavior of collective excitations in fluids: An experimental test for the generalized collective modes theory  

Science Conference Proceedings (OSTI)

The predictions of the generalized collective modes (GCM) theory on the non-hydrodynamic dispersion of collective excitations of liquids and supercritical fluids have been tested against previous inelastic x-ray scattering measurements on samples of increasing complexity. We observed a good agreement between experimental results and theoretical predictions within the hypothesis that sound propagation is adiabatic. Overall, the performed comparison provides an experimental validation of GCM predictions and shows that, even in the transition region between the hydrodynamic and the mesoscopic regimes, thermal fluctuations have a minor influence on the dispersion, whose non-hydrodynamic effects are mostly driven by viscoelastic phenomena.

Bencivenga F.; Cunsolo A.

2012-03-16T23:59:59.000Z

204

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

205

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

206

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

207

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

208

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 m 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

209

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

210

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

211

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

212

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

213

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

214

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

215

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

216

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

217

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

218

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":""}]}

219

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

220

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

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


221

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

222

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

223

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

224

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

225

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

226

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

227

Simulation and Analysis of Converging Shock Wave Test Problems  

Science Conference Proceedings (OSTI)

Results and analysis pertaining to the simulation of the Guderley converging shock wave test problem (and associated code verification hydrodynamics test problems involving converging shock waves) in the LANL ASC radiation-hydrodynamics code xRAGE are presented. One-dimensional (1D) spherical and two-dimensional (2D) axi-symmetric geometric setups are utilized and evaluated in this study, as is an instantiation of the xRAGE adaptive mesh refinement capability. For the 2D simulations, a 'Surrogate Guderley' test problem is developed and used to obviate subtleties inherent to the true Guderley solution's initialization on a square grid, while still maintaining a high degree of fidelity to the original problem, and minimally straining the general credibility of associated analysis and conclusions.

Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

2012-06-21T23:59:59.000Z

228

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

229

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

230

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

231

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

232

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 Schfer

2013-11-26T23:59:59.000Z

233

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

234

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

235

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

236

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

237

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

238

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

239

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. Ngele; M. Heinen; A. J. Banchio; C. Contreras-Aburto

2013-09-13T23:59:59.000Z

240

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

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241

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

242

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

243

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

244

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

245

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

246

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

247

Chesapeake Testing  

Science Conference Proceedings (OSTI)

... Send E-Mail to NVLAP at: NVLAP@nist.gov. Personal Body Armor Testing. ... 7 Ballistic Resistance of Body Armor, Section 7, Ballistic Test Methods. ...

2014-01-03T23:59:59.000Z

248

Structural Testing  

DOE Green Energy (OSTI)

Structural testing at the National Wind Technology Center (NWTC) offers many benefits to wind turbine companies. NWTC includes a new high bay large enough to test any blade expected during the next 5 years. (There are four test bays.) In 1995, NWTC developed a saphisticated data acquisition system, known as the Blade Structural Testing Real-time Acquisition Interface Network (BSTRAIN), to monitor structural testing through 24-hour continuous video surveillance. NWTC recommends ultimate static-strength and fatigue testing, with nondestructive testing in some cases (vibrational testing is covered in a separate information sheet).

NONE

1996-06-01T23:59:59.000Z

249

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

250

Category:Testing Facilities | Open Energy Information  

Open Energy Info (EERE)

Facilities Facilities Jump to: navigation, search This category is defined by the form Testing Facility. Subcategories This category has only the following subcategory. H [×] Hydrodynamic Testing Facility Type‎ 9 pages Pages in category "Testing Facilities" The following 82 pages are in this category, out of 82 total. 1 1.5-ft Wave Flume Facility 10-ft Wave Flume Facility 11-ft Wave Flume Facility 2 2-ft Flume Facility 3 3-ft Wave Flume Facility 5 5-ft Wave Flume Facility 6 6-ft Wave Flume Facility A Alden Large Flume Alden Small Flume Alden Tow Tank Alden Wave Basin B Breakwater Research Facility Bucknell Hydraulic Flume C Carderock 2-ft Variable Pressure Cavitation Water Tunnel Carderock 3-ft Variable Pressure Cavitation Water Tunnel Carderock Circulating Water Channel

251

CTH simulation of PBX-9501 Taylor tests /  

SciTech Connect

During March-May 2011, multiple Taylor impact tests were conducted at LANL, examining the behavior of PBXN-9 and PBX-9501 under rapid loading. Subsequently, a computational hydrodynamics code (CTH) model was developed to mimic the deformation behavior observed in these impact tests with PBX-9501 would likely initiate upon impact. Also examined was whether an inert slud behind the explosive would lead to initiation at lower, more easily attainable velocities. The simplified model used here showed a minimum velocity for ignition of 530 m/s which was unchanged by the addition of a plastic slud behind the sample. The use of a lead slug did lower the minimum velocity to 460 m/s. These values are likely more qualitative at this point because multiple simplifications are currently used in the materials properties and test geometry. The results do show that this approach is capable of determining ignition due to Taylor impact.

Koby, Joseph R.

2011-09-01T23:59:59.000Z

252

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; Garca, A L; Bell, J B

2009-01-01T23:59:59.000Z

253

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

254

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.

255

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

256

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

257

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

258

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

259

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

260

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

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

262

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

263

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

264

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

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

Test Diversity  

E-Print Network (OSTI)

This paper describes a novel method for measuring the degree to which a set of test cases executes a given program in diverse ways with respect to the two fundamental programming concepts: control and data. Test Diversity is a method for measuring the variety of software control flow and data flow, comprising of four new measures: conditional diversity, data diversity, standard deviation of diversity, and test orthogonality. These closely-related measures could be used to evaluate the test effectiveness and the test-effort distribution of a test suite. The Diversity Analyzer is a novel industrial-strength testing tool that can currently perform diversity analysis on software written in C/C++/C#/VB in Windows and.NET environments. The Diversity Analyzer is used to evaluate the fault-detection effectiveness of Test Diversity on various types of industrial projects. Key Words: testing tools, verification, theory, experimentation, conditional diversity, data diversity, standard deviation,

Borislav Nikolik

2006-01-01T23:59:59.000Z

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

TESTING TECHNIQUE  

Science Conference Proceedings (OSTI)

... The cooling bath should ... When testing super-high energy level specimens ... upon the resolution of the scale or readout device at the low end and the ...

2012-10-09T23:59:59.000Z

273

Test Methods  

Science Conference Proceedings (OSTI)

... of the robot, operator control unit (OCU), payload, and batteries Tools needed ... this test method is to quantitatively evaluate the battery capacity per ...

2010-10-05T23:59:59.000Z

274

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

275

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

276

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

277

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

278

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

279

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

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...

,

2013-01-01T23:59:59.000Z

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


281

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

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

284

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

285

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

286

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

287

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

288

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

289

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

290

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

291

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

292

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.

293

ACOUSTICAL TESTING SERVICES TEST METHOD ...  

Science Conference Proceedings (OSTI)

... IEC 60704-2-3 Household and similar electrical appliances - Test code for ... noise emitted and structure-borne vibration induced by small air- moving ...

2013-05-06T23:59:59.000Z

294

test | Department of Energy  

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

test test test test More Documents & Publications Software Testing Checklist February2GuidanceMemorandum.pdf Site Transition Plan Guidance...

295

Test plan  

U.S. Energy Information Administration (EIA)

3.0 TEST PLAN METHODOLOGY 8. 3.1 Assumptions 8. 3.2 Methodology 8. 4.0 COMMENTS ON INITIAL VIEW OF THE DATA 16 1.0 INTRODUCTION. EIA tasked Allied ...

296

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

297

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

298

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

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 Glens 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

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

305

Testing technology  

SciTech Connect

This bulletin from Sandia National Laboratories presents current research highlights in testing technology. Ion microscopy offers new nondestructive testing technique that detects high resolution invisible defects. An inexpensive thin-film gauge checks detonators on centrifuge. Laser trackers ride the range and track helicopters at low-level flights that could not be detected by radar. Radiation transport software predicts electron/photon effects via cascade simulation. Acoustic research in noise abatement will lead to quieter travelling for Bay Area Rapid Transport (BART) commuters.

Not Available

1993-10-01T23:59:59.000Z

306

Test Automation Ant JUnit Test Automation  

E-Print Network (OSTI)

Test Automation Ant JUnit Test Automation Mohammad Mousavi Eindhoven University of Technology, The Netherlands Software Testing 2012 Mousavi: Test Automation #12;Test Automation Ant JUnit Outline Test Automation Ant JUnit Mousavi: Test Automation #12;Test Automation Ant JUnit Why? Challenges of Manual Testing

Mousavi, Mohammad

307

Advanced Vehicle Testing Activity: Energy Storage Testing  

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

Energy Storage Testing to someone by E-mail Share Advanced Vehicle Testing Activity: Energy Storage Testing on Facebook Tweet about Advanced Vehicle Testing Activity: Energy...

308

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

309

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

310

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

311

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

312

test | Department of Energy  

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

test test test test More Documents & Publications 2009 ECR FINAL REPORT 2010 Final ECR 2008 Report Environmental Conflict Resolution...

313

Microgrid Testing  

Science Conference Proceedings (OSTI)

With the publication of IEEE 1574.4 Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems, there is an increasing amount of attention on not only the design and operations of microgrids, but also on the proper operation and testing of these systems. This standard provides alternative approaches and good practices for the design, operation, and integration of microgrids. This includes the ability to separate from and reconnect to part of the utility grid while providing power to the islanded power system. This presentation addresses the industry need to develop standardized testing and evaluation procedures for microgrids in order to assure quality operation in the grid connected and islanded modes of operation.

Shirazi, M.; Kroposki, B.

2012-01-01T23:59:59.000Z

314

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

315

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

316

Aflatoxin Test Kit Laboratory Proficiency Testing  

Science Conference Proceedings (OSTI)

Lab proficiency testing for Aflatoxin test kit to determine Total Aflatoxins.Samples include Peanut Paste, Corn Meal, Milk. Aflatoxin Test Kit Laboratory Proficiency Testing Laboratory Proficiency Program (LPP) aocs applicants certified chemist chemists

317

Test Purpose Generation for Timed Protocol Testing  

Science Conference Proceedings (OSTI)

Test purposes are requirements, usually constructed by hand, which aim at testing critical properties on implementations. These ones are then used by testing methods to generate test cases. Writing them manually is a heavy task, this is why we propose ... Keywords: Timed protocols, conformance testing, test purpose, testability

Sbastien Salva; Antoine Rollet

2009-07-01T23:59:59.000Z

318

Post-quasistatic approximation as a test bed for numerical relativity  

Science Conference Proceedings (OSTI)

It is shown that observers in the standard ADM 3+1 treatment of matter are the same as the observers used in the matter treatment of Bondi: they are comoving and local Minkowskian. Bondi's observers are the basis of the post-quasistatic approximation (PQSA) to study a contracting distribution of matter. This correspondence suggests the possibility of using the PQSA as a test bed for numerical relativity. The treatment of matter by the PQSA and its connection with the ADM 3+1 treatment are presented, for its practical use as a calibration tool and as a test bed for numerical relativistic hydrodynamic codes.

Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

2009-05-15T23:59:59.000Z

319

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

320

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

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


321

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

322

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

323

A Coupled HydrodynamicBottom 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 2528 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

324

Test and Test Equipment Joshua Lottich  

E-Print Network (OSTI)

Test and Test Equipment Joshua Lottich CMPE 640 11/23/05 #12;Testing Verifies that manufactured chip meets design specifications. Cannot test for every potential defect. Modeling defects as faults allows for passing and failing of chips. Ideal test would capture all defects and pass only chips

Patel, Chintan

325

Test Preparation Options Free Test Prep Websites  

E-Print Network (OSTI)

Test Preparation Options Free Test Prep Websites ACT: http: http://www.collegeboard.com/student/testing/sat/prep_one/test.html http://www.number2.com://testprep.princetonreview.com/CourseSearch/Search.aspx?itemCode=17&productType=F&rid=1&zip=803 02 Test Prep Classes Front Range Community College: Classes

Stowell, Michael

326

MECHANICAL TEST LAB CAPABILITIES  

E-Print Network (OSTI)

MECHANICAL TEST LAB CAPABILITIES · Static and cyclic testing (ASTM and non-standard) · Impact drop testing · Slow-cycle fatigue testing · High temperature testing to 2500°F · ASTM/ Boeing/ SACMA standard testing · Ability to design and fabricate non-standard test fixtures and perform non-standard tests

327

Advanced Vehicle Testing Activity: Energy Storage Testing  

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

Energy Storage Testing The Advanced Vehicle Testing Activity is tasked by the U.S. Department of Energy's Vehicle Technologies Office to conduct various types of energy storage...

328

Testing FAQs HAVA Certification and Testing  

Science Conference Proceedings (OSTI)

... In the marketplace, testing provides a vehicle for exchanging information ... For sellers (eg, manufacturers), testing can help to substantiate claims that ...

2012-11-02T23:59:59.000Z

329

Test Anxiety: A Test of Attentional Bias.  

E-Print Network (OSTI)

??Test anxiety is characterized by apprehension, panic, and ruminating thoughts of potential failure that are experienced during an exam situation. In a test conscious society, (more)

Lawson, Darla Jane

2006-01-01T23:59:59.000Z

330

Heat pipe testing program test plan  

SciTech Connect

A test plan is given which describes the tests to be conducted on several typical solar receiver heat pipes. The hardware to be used, test fixtures and rationale of the test program are discussed. The program objective is to perform life testing under simulated receiver conditions, and to conduct performance tests with selected heat pipes to further map their performance, particularly with regard to their transient behavior. Performance requirements are defined. Test fixtures designed for the program are described in detail, and their capabilities for simulating the receiver conditions and their limitations are discussed. The heat pipe design is given. (LEW)

Bienert, W.B.

1980-03-14T23:59:59.000Z

331

Optimization Online - Test  

E-Print Network (OSTI)

Jan 25, 2006 ... Test. Andrew Goldberg (goldberg ***at*** cs.wisc.edu). Abstract: Test. Keywords: Test. Category 1: Infinite Dimensional Optimization...

332

ECT-Test-Methods  

Science Conference Proceedings (OSTI)

ECT-Test-Methods. A, B, C, D. 1, NVLAP ECT Test Method Selection List (updated 2013-12-02). 2, 3, Standard Category, Test ...

2013-12-02T23:59:59.000Z

333

PNNI Routing Interoperability Tests)  

Science Conference Proceedings (OSTI)

... The individual tests are written in TCL. There is a one for one correspondence between the tests in TCL and the tests described ...

334

Face Vendor Recognition Test  

Science Conference Proceedings (OSTI)

... FRVT 2002 consisted of two tests: the High ... goal of the Recognition Performance Test was to ... All systems were tested on a standardized database. ...

2013-07-25T23:59:59.000Z

335

Healthcare Message Test Generation  

Science Conference Proceedings (OSTI)

... a tool that creates a suite of test message instances ... to support an actor based testing framework and ... administer and analyze the results of the tests. ...

2013-06-13T23:59:59.000Z

336

BESTEST Test Suites  

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

BESTEST Test Suites BESTEST (Building Energy Simulation TEST) is a method for testing, diagnosing, and validating the capabilities of building energy simulation programs. The...

337

USGv6 Testing Program  

Science Conference Proceedings (OSTI)

... their own list of tested products accessible ... items arising include soliciting test laboratories and ... participate in the USGv6 testing program, soliciting ...

2013-06-02T23:59:59.000Z

338

Tension-Compression Testing  

Science Conference Proceedings (OSTI)

Tension-Compression Testing. ... version of the tension-compression test, to enable ... loading around draw-beads, where calibration tests must include ...

2013-04-10T23:59:59.000Z

339

Test Advising Framework.  

E-Print Network (OSTI)

??Test cases are represented in various formats depending on the process, the technique or the tool used to generate the tests. While different test case (more)

Wang, Yurong

2013-01-01T23:59:59.000Z

340

Directed Test Suite Augmentation.  

E-Print Network (OSTI)

??Test suite augmentation techniques are used in regression testing to identify code elements affected by changes and to generate test cases to cover those elements. (more)

Xu, Zhihong

2013-01-01T23:59:59.000Z

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


341

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

342

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

343

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

344

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

345

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

346

Concrete Electrical Conductivity Test  

Science Conference Proceedings (OSTI)

Concrete Electrical Conductivity Test. Description/Summary: ... Details. Type of software: Virtual concrete electrical conductivity test. Authors: ...

2013-06-11T23:59:59.000Z

347

Standards Testing Infrastructure  

Science Conference Proceedings (OSTI)

... Group Leader Information Technology Laboratory Software and ... in collaboration with health IT stakeholders ... a variety of testing services: The testing ...

2011-02-02T23:59:59.000Z

348

Special Tests for Thermometry  

Science Conference Proceedings (OSTI)

Special Tests for Thermometry. ... Proficiency-test artifacts (eg SPRTs); Bridge certification; Evaluation of prototype thermometric devices. ...

2013-06-11T23:59:59.000Z

349

Laboratory Corrosion Tests  

Science Conference Proceedings (OSTI)

Table 2   Laboratory corrosion tests...Salt spray test NaCl solution Ocean climate Acetic acid salt spray test NaCl + CH 3 COOH Salted roads Copper-accelerated acetic acid salt spray test As in acetic acid salt spray test As in acetic acid salt spray test, but more aggressive Immersion tests Artificial sweat test ? Wearing of decorative...

350

Home Smoke Alarm Tests  

Science Conference Proceedings (OSTI)

... alarm technologies in a controlled laboratory test ... arrangements and maximize the test instrumentation. ... Centers for Disease Control and Prevention ...

2013-07-07T23:59:59.000Z

351

Statistical Inference: Hypothesis Test  

E-Print Network (OSTI)

1 Statistical Inference: Hypothesis Test GOG 502/PLN 504 Youqin Huang 1 Review: The Z t ( )± Today's topic: Hypothesis Tests What is hypothesis test? Elements, steps, types of hypothesis test Significance test for a mean Small vs. large sample Significance test for proportion GOG 502/PLN 504 Youqin

Huang, Youqin

352

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

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

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

353

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

354

Hybrid Electric Vehicle Testing  

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

Transportation Association Conference Transportation Association Conference Vancouver, Canada December 2005 Hybrid Electric Vehicle Testing Jim Francfort U.S. Department of Energy - FreedomCAR & Vehicle Technologies Program, Advanced Vehicle Testing Activity INL/CON-05-00964 Presentation Outline * Background & goals * Testing partners * Hybrid electric vehicle testing - Baseline performance testing (new HEV models) - 1.5 million miles of HEV fleet testing (160k miles per vehicle in 36 months) - End-of-life HEV testing (rerun fuel economy & conduct battery testing @ 160k miles per vehicle) - Benchmark data: vehicle & battery performance, fuel economy, maintenance & repairs, & life-cycle costs * WWW information location Background * Advanced Vehicle Testing Activity (AVTA) - part of the

355

ZiaTest  

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

Trinity-NERSC8-RFP NERSC-8 Trinity Benchmarks ZiaTest ZiaTest Description This test executes a new proposed standard benchmark method for MPI startup that is intended to...

356

The Turing Test*  

Science Conference Proceedings (OSTI)

Turing's test has been much misunderstood. Recently unpublished material by Turing casts fresh light on his thinking and dispels a number of philosophical myths concerning the Turing test. Properly understood, the Turing test withstands objections that ...

B. Jack Copeland

2000-11-01T23:59:59.000Z

357

Test | Department of Energy  

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

Test Test Summary Test More Documents & Publications Evaluation Report: OAS-M-12-01 Evaluation Report: OAS-M-11-01 Evaluation Report: OAS-L-13-01...

358

ZiaTest  

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

ZiaTest ZiaTest Description This test executes a new proposed standard benchmark method for MPI startup that is intended to provide a realistic assessment of both launch and wireup...

359

Hybrid Electric Vehicle Testing  

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

- 1.5 million miles of HEV fleet testing (160k miles per vehicle in 36 months) - End-of-life HEV testing (rerun fuel economy & conduct battery testing @ 160k miles per vehicle) -...

360

Acceptance Test Refactoring  

E-Print Network (OSTI)

Abstract. In Executable Acceptance Test Driven Development, acceptance tests represent the requirements of a software system. As requirements change over time, the acceptance tests have to be updated and maintained. This process can be time-consuming and risky as acceptance tests lack the regression safety net that production code has. Refactoring of acceptance tests is used to keep the fixtures and the acceptance test definitions consistent.

Heiko Ordelt; Frank Maurer

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

Advanced Vehicle Testing Activity: Testing Reports  

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

Reports NEVAmerica Baseline Performance Testing Summaries A neighborhood electric vehicle (NEV) is defined as a "low-speed vehicle" (LSV) by the National Highway Traffic...

362

Test Request LTFY-2  

SciTech Connect

This test request defines pre-test data for the irradiation of enriched yttrium-uranium hydride samples in the LITR C-48 facility.

1964-12-01T23:59:59.000Z

363

Overview of Conformance Testing  

Science Conference Proceedings (OSTI)

... require not just one test per error but one test per possible permutation of errors. ... to maximize automation and minimize human intervention. ...

2010-10-05T23:59:59.000Z

364

OMB MPI Tests  

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

OMB MPI Tests OMB MPI Tests Description The Ohio MicroBenchmark suite is a collection of independent MPI message passing performance microbenchmarks developed and written at The...

365

PRACTICAL COMBINATORIAL TESTING  

Science Conference Proceedings (OSTI)

... boot-up. The initial test configuration (Figure 14) was drawn from the library of pre-computed sequence tests. Some changes ...

2012-12-13T23:59:59.000Z

366

PNGV battery test manual  

DOE Green Energy (OSTI)

This manual defines a series of tests to characterize aspects of the performance or life cycle behavior of batteries for hybrid electric vehicle applications. Tests are defined based on the Partnership for New Generation Vehicles (PNGV) program goals, although it is anticipated these tests may be generally useful for testing energy storage devices for hybrid electric vehicles. Separate test regimes are defined for laboratory cells, battery modules or full size cells, and complete battery systems. Some tests are common to all three test regimes, while others are not normally applicable to some regimes. The test regimes are treated separately because their corresponding development goals are somewhat different.

NONE

1997-07-01T23:59:59.000Z

367

Robotics Test Facility  

Science Conference Proceedings (OSTI)

... 5000 square foot) high bay, holding most of the test methods; ... to help engineers view robot performance remotely and for recording testing events. ...

2013-05-23T23:59:59.000Z

368

Test Cell Location  

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

2012 Fiat 500 Test Cell Location 2WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional Vehicle Dynamometer...

369

Iris Device Qualification Test  

Science Conference Proceedings (OSTI)

... Device Qualification Test (IDQT). July 15, 2013 - Slides from Workshop. Slides that give the detailed technical approach toward the IDQT tests are ...

2013-07-16T23:59:59.000Z

370

Test Cell Location  

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

2013 Nissan Altima Test Cell Location 2WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional Vehicle...

371

Energy Storage Testing  

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

Energy Storage Testing The Advanced Vehicle Testing Activity is tasked by the U.S. Department of Energys Vehicle Technology Program to conduct various types of energy storage...

372

NREL: Wind Research - Testing  

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

Testing Photo of a large wind turbine blade sticking out of the structural testing laboratory; it is perpendicular to a building at the National Wind Technology Center. A...

373

Why Test Suites  

Science Conference Proceedings (OSTI)

In the marketplace, testing provides a vehicle for exchanging information ... For sellers (eg, manufacturers), testing can help to substantiate claims that ...

2012-11-02T23:59:59.000Z

374

Test Cell Location  

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

Focus Test Cell Location 2WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional Vehicle Dynamometer Input...

375

Test Cell Location  

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

Chrysler 300 Test Cell Location 2WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional Vehicle Dynamometer...

376

Test Cell Location  

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

Mazda 3 i-Stop Test Cell Location APRF- 4WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional- Start Stop...

377

NVLAP Biometrics Testing LAP  

Science Conference Proceedings (OSTI)

... reserves the right to update, modify or rename the set of test methods associated with any scope of accreditation. Proficiency Testing Requirements. ...

2013-07-26T23:59:59.000Z

378

Test report for core drilling ignitability testing  

DOE Green Energy (OSTI)

Testing was carried out with the cooperation of Westinghouse Hanford Company and the United States Bureau of Mines at the Pittsburgh Research Center in Pennsylvania under the Memorandum of Agreement 14- 09-0050-3666. Several core drilling equipment items, specifically those which can come in contact with flammable gasses while drilling into some waste tanks, were tested under conditions similar to actual field sampling conditions. Rotary drilling against steel and rock as well as drop testing of several different pieces of equipment in a flammable gas environment were the specific items addressed. The test items completed either caused no ignition of the gas mixture, or, after having hardware changes or drilling parameters modified, produced no ignition in repeat testing.

Witwer, K.S.

1996-08-08T23:59:59.000Z

379

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

380

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

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

Advanced empirical testing  

Science Conference Proceedings (OSTI)

In today's industrial applications, we see that knowledge systems are successfully implemented. However, critical domains require the elaborate and thoughtful validation of the knowledge bases before the deployment. Empirical testing, also known as regression ... Keywords: Evaluation, Knowledge quality, Quality measures, Regression testing, Test cases, Test visualization, Validation, Verification

Joachim Baumeister

2011-02-01T23:59:59.000Z

382

Solderability test system  

DOE Patents (OSTI)

A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time.

Yost, Fred (Cedar Crest, NM); Hosking, Floyd M. (Albuquerque, NM); Jellison, James L. (Albuquerque, NM); Short, Bruce (Beverly, MA); Giversen, Terri (Beverly, MA); Reed, Jimmy R. (Austin, TX)

1998-01-01T23:59:59.000Z

383

Solderability test system  

DOE Patents (OSTI)

A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time. 11 figs.

Yost, F.; Hosking, F.M.; Jellison, J.L.; Short, B.; Giversen, T.; Reed, J.R.

1998-10-27T23:59:59.000Z

384

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

385

Detailed Test Information  

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

Detailed Test Information Detailed Test Information EPA tests vehicles by running them through a series of driving routines, also called cycles or schedules, that specify vehicle speed for each point in time during the laboratory tests. For 2007 and earlier model year vehicles, only the city and highway schedules were used. Beginning with 2008 models, three additional tests will be used to adjust the city and highway estimates to account for higher speeds, air conditioning use, and colder temperatures. Note: EPA has established testing criteria for electric vehicles and plug-in hybrids that are slightly different than those for conventional vehicles. New Tests City Highway High Speed Air Conditioning Cold Temperature Detailed Comparison EPA Federal Test Procedure (City Schedule): Shows vehicle speed (mph) at each second of test

386

ECN Pressure Test  

SciTech Connect

This note describes: the rationale for the test pressure of the inner ECN cryostat vessel, the equipment to be used in this test, the test procedure, the status of the vessel prior to the test, the actual test results, and a schematic diagram of the testing set up and the pressure testing permit. The test, performed in the evening of July 17, 1991, was a major success. Based on a neglible pressure drop indicated on the pressure gages (1/4 psi), the vessel appeared to be structurally sound throughout the duration of the test (approx. 1.5 hrs.). No pressure increases were observed on the indicators looking at the beam tube bellows volumes. There was no indication of bubbles form the soap test on the welds and most of the fittings that were checked. There were some slight deviations in the actual procedure used. The UO filter was removed after the vessel had bled down to about 18 psig in order to speed up that aspect of the test. The rationale was that the higher velocity gas had already passed through at the higher pressures and there was no visible traces of the black uo particles. The rate of 4 psi/10 minutes seemed incredibly slow and often that time was reduced to just over half that rate. The testing personnel was allowed to stay in the pit throughout the duration of the test; this was a slight relaxation of the rules.

Dixon, K.; /Fermilab

1991-07-18T23:59:59.000Z

387

Advanced Vehicle Testing Activity: Oil Bypass Filter Testing...  

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

Testing Reports to someone by E-mail Share Advanced Vehicle Testing Activity: Oil Bypass Filter Testing Reports on Facebook Tweet about Advanced Vehicle Testing Activity: Oil...

388

Advanced Vehicle Testing Activity: Hybrid Electric Vehicle Testing...  

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

Testing Reports to someone by E-mail Share Advanced Vehicle Testing Activity: Hybrid Electric Vehicle Testing Reports on Facebook Tweet about Advanced Vehicle Testing Activity:...

389

Advanced Vehicle Testing Activity: Urban Electric Vehicle Testing...  

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

Testing Reports to someone by E-mail Share Advanced Vehicle Testing Activity: Urban Electric Vehicle Testing Reports on Facebook Tweet about Advanced Vehicle Testing Activity:...

390

Gas Test Loop Booster Fuel Hydraulic Testing  

SciTech Connect

The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3.

Gas Test Loop Hydraulic Testing Staff

2006-09-01T23:59:59.000Z

391

MHD seawater thruster performance: A comparison of predictions with experimental results from a two Tesla test facility  

DOE Green Energy (OSTI)

A two Tesla test facility was designed, built, and operated to investigate the performance of magnetohydrodynamic (MHD) seawater thrusters. The results of this investigation are used to validate a design oriented MHD thruster performance computer code. The thruster performance code consists of a one-dimensional MHD hydrodynamic model coupled to a two-dimensional electrical model. The code includes major loss mechanisms affecting the performance of the thruster. Among these losses are the joule dissipation losses, frictional losses, electrical end losses, and single electrode potential losses. The facility test loop, its components, and their design are presented in detail. Additionally, the test matrix and its rationale are discussed. Representative experimental results of the test program are presented, and are compared to pretest computer model predictions. Good agreement between predicted and measured data has served to validate the thruster performance computer models.

Picologlou, B.F.; Doss, E.D.; Geyer, H.K. (Argonne National Lab., IL (United States)); Sikes, W.C.; Ranellone, R.F. (Newport News Shipbuilding and Dry Dock Co., VA (United States))

1992-01-01T23:59:59.000Z

392

Check for peroxides every 6 months. opened test 1 test 2 test 3  

E-Print Network (OSTI)

Check for peroxides every 6 months. opened test 1 test 2 test 3 date initials Check for peroxides every 6 months. opened test 1 test 2 test 3 date initials Check for peroxides every 6 months. Test strips can be obtained from EH&S, 5-8200 opened test 1 test 2 test 3 date initials Check for peroxides

Manning, Sturt

393

Laboratory Proficiency Testing Series  

Science Conference Proceedings (OSTI)

Lab Proficiency Testing (LPP), Aflatoxin, Aflatoxin Test Kit, Peanut Paste and Corn Meal, Biodiesel Feedstock, Cholesterol, Cottonseed, Cottonseed Oil, Edibile Fat, Feed Microscopy, Fish Meal, Fumonisin, Gas Chromatography, Gentically Modified Organism, G

394

Laboratory Proficiency Testing Program  

Science Conference Proceedings (OSTI)

AOCS provides a Laboratory Proficiency Program (LPP). Formerly the Smalley Check Sample Program LPP is a collaborative proficiency testing service for oil and fat related commodities, oilseeds, oilseed meals, and edible fats. Laboratory Proficiency Testing

395

I/O Test  

E-Print Network (OSTI)

IO TEST is intended as a hardware testing and debugging aid for use with the PDP-6 and its associated input multiplexer (analog to digital converter) and output multiplexer (digital to analog converter). While all characters ...

Beeler, Michael

1967-10-01T23:59:59.000Z

396

A Test Example - CECM  

E-Print Network (OSTI)

May 10, 2000 ... A Test Example. Consider A:=21/6+31/5. The advantage of picking a simple algebraic number for our test is that we can easily precompute the...

397

Automatic Test Factoring for Java  

E-Print Network (OSTI)

Test factoring creates fast, focused unit tests from slow system-widetests; each new unit test exercises only a subset of the functionalityexercised by the system test. Augmenting a test suite with factoredunit tests ...

Saff, David

2005-06-08T23:59:59.000Z

398

Pig shipping container test sequence  

SciTech Connect

This test plan outlines testing of the integrity of the pig shipping container. It is divided into four sections: (1) drop test requirements; (2) test preparations; (3) perform drop test; and (4) post-test examination.

Adkins, H.E. Jr.

1995-01-13T23:59:59.000Z

399

Combinatorial Test Coverage Measurement  

Science Conference Proceedings (OSTI)

... Statement coverage: This is the simplest of coverage criteria the percentage of statements exercised by the test set. ...

400

Personal Body Armor Testing  

Science Conference Proceedings (OSTI)

Directory of Accredited Laboratories. Personal Body Armor Testing. In 2006, the US Department of Justice (DOJ) National ...

2014-01-03T23:59:59.000Z

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

Testing EIA Surveys  

U.S. Energy Information Administration (EIA)

... Interviews Without Debriefings Respondents do not see the questionnaire prior to the interview Structured protocol Test question wording and interpretation ...

402

Advance Testing Company Inc.  

Science Conference Proceedings (OSTI)

... Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter. ... Practice for the Accreditation of Testing Agencies for Unit Masonry. ...

2013-09-27T23:59:59.000Z

403

Seattle Asbestos Test Bellevue  

Science Conference Proceedings (OSTI)

Seattle Asbestos Test Bellevue. NVLAP Lab Code: 200876-0. Address and Contact Information: 12727 Northup Way, Suite ...

2013-08-02T23:59:59.000Z

404

Seattle Asbestos Test, LLC  

Science Conference Proceedings (OSTI)

Seattle Asbestos Test, LLC. NVLAP Lab Code: 200768-0. Address and Contact Information: 19701 Scriber Lake Road, Suite ...

2013-08-02T23:59:59.000Z

405

Retlif Testing Laboratories  

Science Conference Proceedings (OSTI)

... of radio disturbance characteristics of electrical motor-operated and ... and Test Procedures for Airborne Equipment - Section 15 - Magnetic Effect. ...

2014-01-03T23:59:59.000Z

406

Computer Forensics Tool Testing  

Science Conference Proceedings (OSTI)

Computer Forensics Tool Testing (CFTT). Summary: For more information, visit: http://www.cftt.nist.gov/. There is a critical ...

2010-10-05T23:59:59.000Z

407

Control of Test Conduct  

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

2 Revision 1 Effective June 2008 Control of Test Conduct Prepared by Electric Transportation Applications Prepared by: Date: Garrett P....

408

Coaxial test fixture  

DOE Patents (OSTI)

This invention pertains to arrangements for performing electrical tests on contact material samples, and in particular for testing contact material test samples in an evacuated environment under high current loads. Frequently, it is desirable in developing high-current separable contact material, to have at least a preliminary analysis of selected candidate conductor materials. Testing of material samples will hopefully identify materials unsuitable for high current electrical contact without requiring incorporation of the materials into a completed and oftentimes complex structure.

Praeg, W.F.

1984-03-30T23:59:59.000Z

409

Review of Test Results  

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

GAC004 Revision 1 Effective June 2008 Review of Test Results Prepared by Electric Transportation Applications Prepared by: Date: Garrett...

410

Security Resiliency Testing  

Science Conference Proceedings (OSTI)

An accepted practice within the electric sector is to pre-stage and test equipment before deployment. Verification of functionality, operating parameters, and interoperability of equipment to be deployed can often be incorporated into predeployment testing. This testing may also support the selection of features responsible for the security of the host equipment. However, some security features and many aspects of resiliency testing may require activation, interaction, and interoperability with an ...

2013-12-02T23:59:59.000Z

411

Cryptographic and Security Testing  

Science Conference Proceedings (OSTI)

Directory of Accredited Laboratories. Cryptographic and Security Testing. ... TX. atsec information security corporation, Austin, TX [200658- 0] VA. ...

2013-12-27T23:59:59.000Z

412

HEALTHCARE INFORMATION TECHNOLOGY TESTING  

Science Conference Proceedings (OSTI)

... test reports created for validation purposes and submitted to the certification body, the ... CHP Certified Health Information Technology Products List ...

2013-11-22T23:59:59.000Z

413

Testing hypergraph colorability  

Science Conference Proceedings (OSTI)

We study the problem of testing properties of hypergraphs. The goal of property testing is to distinguish between the case whether a given object has a certain property or is "far away" from the property. We prove that the fundamental problem of l-colorability ... Keywords: hypergraph algorithms, hypergraph coloring, hypergraphs, property testing

Artur Czumaj; Christian Sohler

2005-02-01T23:59:59.000Z

414

Quasi-random testing  

Science Conference Proceedings (OSTI)

Quasi-random sequences, also known as low-discrepancy or low-dispersion sequences, are sequences of points in an n-dimensional unit hypercube. These sequences have the property that points are spread more evenly throughout the cube than random point ... Keywords: adaptive random testing, automated testing, low-discrepancy sequence, quasi-random sequence, random testing

Tsong Yueh Chen; Robert Merkel

2005-11-01T23:59:59.000Z

415

Toroidal simulation magnet tests  

SciTech Connect

A number of different schemes for testing superconducting coils in a simulated tokamak environment are analyzed for their merits relative to a set of test criteria. Two of the concepts are examined in more detail: the so-called cluster test scheme, which employs two large background field coils, one on either side of the test coil, and the compact torus, a low-aspect ratio toroidal array of a small number of coils in which all of the coils are essentially test coils. Simulation of the pulsed fields of the tokamak is discussed briefly. (auth)

Walstrom, P.L.; Domm, T.C.

1975-01-01T23:59:59.000Z

416

Test Cell Location  

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

Mazda 3 i-Stop Mazda 3 i-Stop Test Cell Location APRF- 4WD Vehicle Setup Information Downloadable Dynamometer Database (D 3 )- Test Summary Sheet Vehicle Architecture Conventional- Start Stop Vehicle Dynamometer Input Document Date 11/20/2012 Advanced Powertrain Research Facility Test weight [lb] 3250 Vehicle Dynamometer Input Document Date 11/20/2012 Revision Number 1 Advanced Powertrain Research Facility Test weight [lb] Target A [lb] 3250 31.2 Target B [lb/mph] Target C [lb/mph^2] 0.462 0.014 Test Fuel Information - Vehicle equipped with with i-Stop package - Manual Transmission - All tests completed in ECO mode - EPA shift schedule modified based on vehicle shift light activity Revision Number 1 Notes: Fuel type EPA Tier II EEE Gasoline Test Fuel Information - Vehicle equipped with with i-Stop package

417

RMOTC - Testing - Geothermal  

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

Geothermal Testing Geothermal Testing Notice: As of July 15th 2013, the Department of Energy announced the intent to sell Naval Petroleum Reserve Number 3 (NPR3). The sale of NPR-3 will also include the sale of all equipment and materials onsite. A decision has been made by the Department of Energy to complete testing at RMOTC by July 1st, 2014. RMOTC will complete testing in the coming year with the currently scheduled testing partners. For more information on the sale of NPR-3 and sale of RMOTC equipment and materials please join our mailing list here. With the existing geologic structure at RMOTC, promising potential exists for Enhanced Geothermal System (EGS) testing. The field also has two reliable water resources for supporting low-temperature geothermal testing.

418

Pendulum detector testing device  

DOE Patents (OSTI)

A detector testing device is described which provides consistent, cost-effective, repeatable results. The testing device is primarily constructed of PVC plastic and other non-metallic materials. Sensitivity of a walk-through detector system can be checked by: (1) providing a standard test object simulating the mass, size and material content of a weapon or other contraband, (2) suspending the test object in successive positions, such as head, waist and ankle levels, simulating where the contraband might be concealed on a person walking through the detector system; and (3) swinging the suspended object through each of the positions, while operating the detector system and observing its response. The test object is retained in a holder in which the orientation of the test device or target can be readily changed, to properly complete the testing requirements. 5 figs.

Gonsalves, J.M.

1997-09-30T23:59:59.000Z

419

Nanoparticle toxicity testing  

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

Nanoparticle toxicity testing Nanoparticle toxicity testing 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit Nanoparticle toxicity testing Assessing the potential health hazards of nanotechnology March 25, 2013 Robot In the search for more accurate and efficient techniques to evaluate the health hazards of nanoparticles, Los Alamos researchers are developing artificial human tissues and organs to replace animal test subjects. A new approach to toxicity testing under development at Los Alamos uses artificial tissue and artificial organs instead of animal testing Manufactured nanoparticles such as buckyballs and carbon nanotubes, used in products ranging from sunscreens to solar panels, are proliferating so quickly that safety testing for potential health hazards-similar to those

420

Pendulum detector testing device  

DOE Patents (OSTI)

A detector testing device which provides consistent, cost-effective, repeatable results. The testing device is primarily constructed of PVC plastic and other non-metallic materials. Sensitivity of a walk-through detector system can be checked by: 1) providing a standard test object simulating the mass, size and material content of a weapon or other contraband, 2) suspending the test object in successive positions, such as head, waist and ankle levels, simulating where the contraband might be concealed on a person walking through the detector system; and 3) swinging the suspended object through each of the positions, while operating the detector system and observing its response. The test object is retained in a holder in which the orientation of the test device or target can be readily changed, to properly complete the testing requirements.

Gonsalves, John M. (Modesto, CA)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hydrodynamic test darht" 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

BENCHMARK TESTING A.1 Benchmark Testing Design  

E-Print Network (OSTI)

­and­bound search module first. * Enter the number of system­suggested terms or `0' to quit ?? 30 --* User supplied search process. * Enter the number of system­suggested terms or `0' to quit ?? 10 --* Notice Processing) and different numbers of search terms. We tested 5 cases each for queries with 1 term, 2 terms, 3

422

COLD TEST LOOP INTEGRATED TEST LOOP RESULTS  

Science Conference Proceedings (OSTI)

A testing facility (Cold Test Loop) was constructed and operated to demonstrate the efficacy of the Accelerated Waste Retrieval (AWR) Project's planned sluicing approach to the remediation of Silos 1 and 2 at the Fernald Environmental Management Project near Cincinnati, Ohio. The two silos contain almost 10,000 tons of radium-bearing low-level waste, which consists primarily of solids of raffinates from processing performed on ores from the Democratic Republic of Congo (commonly referred to as ''Belgium Congo ores'') for the recovery of uranium. These silos are 80 ft in diameter, 36 ft high to the center of the dome, and 26.75 ft to the top of the vertical side walls. The test facility contained two test systems, each designed for a specific purpose. The first system, the Integrated Test Loop (ITL), a near-full-scale plant including the actual equipment to be installed at the Fernald Site, was designed to demonstrate the sluicing operation and confirm the selection of a slurry pump, the optimal sluicing nozzle operation, and the preliminary design material balance. The second system, the Component Test Loop (CTL), was designed to evaluate many of the key individual components of the waste retrieval system over an extended run. The major results of the initial testing performed during July and August 2002 confirmed that the AWR approach to sluicing was feasible. The ITL testing confirmed the following: (1) The selected slurry pump (Hazleton 3-20 type SHW) performed well and is suitable for AWR application. However, the pump's motor should be upgraded to a 200-hp model and be driven by a 150-hp variable-frequency drive (VFD). A 200-hp VFD is not much more expensive and would allow the pump to operate at full speed. (2) The best nozzle performance was achieved by using 15/16-in. nozzles operated alternately. This configuration appeared to most effectively mine the surrogate. (3) The Solartron densitometer, which was tested as an alternative mass flow measurement device, did not operate effectively. Consequently, it is not suitable for application to the AWR process. (4) Initially, the spray ring (operated at approximately 2300 psi) and the nozzles provided by the pump vendor did not perform acceptably. The nozzles were replaced with a more robust model, and the performance was then acceptable. (5) The average solids concentration achieved in the slurry before Bentogrout addition was approximately 16% by weight. The solids concentration of the slurry after Bentogrout addition ranged from 26% to approximately 40%. The slurry pump and ITL system performed well at every concentration. No line plugging or other problems were noted. The results of the CTL runs and later ITL testing are summarized in an appendix to this report.

Abraham, TJ

2003-10-22T23:59:59.000Z

423

Evolving Einstein's Field Equations with Matter: The ``Hydro without Hydro'' Test  

E-Print Network (OSTI)

We include matter sources in Einstein's field equations and show that our recently proposed 3+1 evolution scheme can stably evolve strong-field solutions. We insert in our code known matter solutions, namely the Oppenheimer-Volkoff solution for a static star and the Oppenheimer-Snyder solution for homogeneous dust sphere collapse to a black hole, and evolve the gravitational field equations. We find that we can evolve stably static, strong-field stars for arbitrarily long times and can follow dust sphere collapse accurately well past black hole formation. These tests are useful diagnostics for fully self-consistent, stable hydrodynamical simulations in 3+1 general relativity. Moreover, they suggest a successive approximation scheme for determining gravitational waveforms from strong-field sources dominated by longitudinal fields, like binary neutron stars: approximate quasi-equilibrium models can serve as sources for the transverse field equations, which can be evolved without having to re-solve the hydrodynamical equations (``hydro without hydro'').

Thomas W. Baumgarte; Scott A. Hughes; Stuart L. Shapiro

1999-02-09T23:59:59.000Z

424

Advanced Technology Vehicle Testing  

DOE Green Energy (OSTI)

The light-duty vehicle transportation sector in the United States depends heavily on imported petroleum as a transportation fuel. The Department of Energys Advanced Vehicle Testing Activity (AVTA) is testing advanced technology vehicles to help reduce this dependency, which would contribute to the economic stability and homeland security of the United States. These advanced technology test vehicles include internal combustion engine vehicles operating on 100% hydrogen (H2) and H2CNG (compressed natural gas) blended fuels, hybrid electric vehicles, neighborhood electric vehicles, urban electric vehicles, and electric ground support vehicles. The AVTA tests and evaluates these vehicles with closed track and dynamometer testing methods (baseline performance testing) and accelerated reliability testing methods (accumulating lifecycle vehicle miles and operational knowledge within 1 to 1.5 years), and in normal fleet environments. The Arizona Public Service Alternative Fuel Pilot Plant and H2-fueled vehicles are demonstrating the feasibility of using H2 as a transportation fuel. Hybrid, neighborhood, and urban electric test vehicles are demonstrating successful applications of electric drive vehicles in various fleet missions. The AVTA is also developing electric ground support equipment (GSE) test procedures, and GSE testing will start during the fall of 2003. All of these activities are intended to support U.S. energy independence. The Idaho National Engineering and Environmental Laboratory manages these activities for the AVTA.

James Francfort

2003-11-01T23:59:59.000Z

425

Topological Test Spaces  

E-Print Network (OSTI)

A test space is the set of outcome-sets associated with a collection of experiments. This notion provides a simple mathematical framework for the study of probabilistic theories -- notably, quantum mechanics -- in which one is faced with incommensurable random quantities. In the case of quantum mechanics, the relevant test space, the set of orthonormal bases of a Hilbert space, carries significant topological structure. This paper inaugurates a general study of topological test spaces. Among other things, we show that any topological test space with a compact space of outcomes is of finite rank. We also generalize results of Meyer and Clifton-Kent by showing that, under very weak assumptions, any second-countable topological test space contains a dense semi-classical test space.

Alexander Wilce

2004-05-28T23:59:59.000Z

426

STAR Test Environment  

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

STAR Test Environment STAR Test Environment STAR Test Environment These instructions describe how to set up the STAR environment independent of the production environment in order to test different installations in $OPTSTAR and $GROUP_DIR. If you want to modify those installations you will need access to the starofl account. Bypass STAR envionment login Edit your ~/.pdsf_setup file changing the STAR_LINUX_SETUP to "use_none" and start a new session. You should not see all the STAR environmental variables defined when you do this (and it will probably be much quicker than usual, too). Do a manual STAR login If you want to modify what test environment you use copy the test login scripts to your own working area: cp -r /common/star/startest /path/to/myworkdir/. If you don't want to modify these files you can source them directly from

427

RMOTC TEST REPORT  

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

MUD DEVIL - DEAERATOR MIXER MUD DEVIL - DEAERATOR MIXER MARCH 30, 1995 RMOTC TEST REPORT Mud Devil - Deaerator Mixer Project Test Results Prepared for: INDUSTRY PUBLICATION Prepared by: MICHAEL R. TYLER RMOTC Field Engineer March 30, 1995 551103/9507:jb ABSTRACT The Rocky Mountain Oilfield Testing Center (RMOTC) conducted a field test on the MUD DEVIL - Deaerator Mixer (MDDM), at the Naval Oil Shale Reserve No. 3 (NOSR-3) located west of Rifle, Colorado. Industrial Screen and Maintenance of Casper, Wyoming, manufactures the MDDM high-shear pin mixing system used to blend products in drilling fluid systems. The test was a comparison between DOE Well 1 -M-1 8 drilled without the MDDM and a sidetrack Well 1-M-18 ST drilled with the MDDM. Test results show that the MDDM, when properly used, reduced the usage of drilling fluid products, decreased water

428

Advanced Technology Vehicle Testing  

DOE Green Energy (OSTI)

The goal of the U.S. Department of Energy's Advanced Vehicle Testing Activity (AVTA) is to increase the body of knowledge as well as the awareness and acceptance of electric drive and other advanced technology vehicles (ATV). The AVTA accomplishes this goal by testing ATVs on test tracks and dynamometers (Baseline Performance testing), as well as in real-world applications (Fleet and Accelerated Reliability testing and public demonstrations). This enables the AVTA to provide Federal and private fleet managers, as well as other potential ATV users, with accurate and unbiased information on vehicle performance and infrastructure needs so they can make informed decisions about acquiring and operating ATVs. The ATVs currently in testing include vehicles that burn gaseous hydrogen (H2) fuel and hydrogen/CNG (H/CNG) blended fuels in internal combustion engines (ICE), and hybrid electric (HEV), urban electric, and neighborhood electric vehicles. The AVTA is part of DOE's FreedomCAR and Vehicle Technologies Program.

James Francfort

2004-06-01T23:59:59.000Z

429

Distributed Generation Biofuel Testing  

Science Conference Proceedings (OSTI)

This Technical Update report documents testing performed to assess aspects of using biofuel as an energy source for distributed generation. Specifically, the tests involved running Caterpillar Power Module compression ignition engines on palm methyl ester (PME) biofuel and comparing the emissions to those of the same engines running on ultra-low-sulfur diesel fuel. Fuel consumption and energy efficiency were also assessed, and some relevant storage and handling properties of the PME were noted. The tests...

2011-12-06T23:59:59.000Z

430

EXTINGUISHMENT TESTS OF CONTINUOUSLY ...  

Science Conference Proceedings (OSTI)

... Page 8. Table 2. Summary of Conductive Heating Tests with HFC-227ea. CONDOM CONDO06 CONDO07 CONDO13 CONDO 1 8 SAMPLE -=I=- ...

2011-10-13T23:59:59.000Z

431

Next Generation Test Bed  

Science Conference Proceedings (OSTI)

... 3 machine rooms (safety, security, power, & A/C). Supports COOP ... ii. Developing methods and technologies for next generation biometric testing. ...

2011-12-15T23:59:59.000Z

432

Chemical Testing of Textiles  

Science Conference Proceedings (OSTI)

Chemical Testing of Textiles is edited by Qinguo Fan and covers more subjects than the title implies. These subjects include fiber and yarn identification,...

433

Nonlinear Optimization Test  

E-Print Network (OSTI)

Jun 8, 2000 ... Nonlinear Optimization Test Goux Jean-Pierre Abstract : this is my abstract. Keywords : this are keywords. Citation: : this is a citation. Download...

434

MechanicalTesting  

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

structures, validation of encapsulant cure stress models, development of frac- ture mechanics tests for use in adhesion studies and understanding the failure mechanism of...

435

TYPES OF FIELD TESTING  

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

TYPES OF FIELD TESTING Convincing proof of energy savings and performance in a specific building and occupant context If direct proof of savings is desired, the only feasible...

436

Diesel Engine Idling Test  

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

analyses. A secondary benefit of this initial destructive analysis was that it allowed NTS personnel to refine their filter testing protocol and give their technicians a chance...

437

Lighting Systems Test Facilities  

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

Measurement equipment with light beam Lighting Systems Test Facilities NOTICE Due to the current lapse of federal funding, Berkeley Lab websites are accessible, but may not be...

438

MEMS Test Working Group  

Science Conference Proceedings (OSTI)

... p2. Top view of cantilevers in in-plane length group. p1. Unconventional anchor design. Same anchor design as in thickness test structures. ...

2013-05-03T23:59:59.000Z

439

Healthcare Information Technology Testing  

Science Conference Proceedings (OSTI)

... products. NIST Handbook 150 and NIST Handbook 150-31 provide the general and the specific requirements for all HIT testing. ...

2013-09-13T23:59:59.000Z

440

Optimum Statistical Test Procedure  

E-Print Network (OSTI)

In this paper we obtain a test which minimizes the sum of the two error probabilities irrespective of whether $\\sigma^2$ is known or unknown.

Rajesh Singh; Jayant Singh; Florentin Smarandache

2009-04-10T23:59:59.000Z

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


441

Leak test fitting  

DOE Patents (OSTI)

A hollow fitting for use in gas spectrometry leak testing of conduit joints is divided into two generally symmetrical halves along the axis of the conduit. A clip may quickly and easily fasten and unfasten the halves around the conduit joint under test. Each end of the fitting is sealable with a yieldable material, such as a piece of foam rubber. An orifice is provided in a wall of the fitting for the insertion or detection of helium during testing. One half of the fitting also may be employed to test joints mounted against a surface.

Pickett, Patrick T. (Kettering, OH)

1981-01-01T23:59:59.000Z

442

Voting System Testing  

Science Conference Proceedings (OSTI)

... required to be accredited to all core test methods involving: 1) technical data package review; 2) physical configuration audit (including examination ...

2013-09-06T23:59:59.000Z

443

test output enable Veto  

E-Print Network (OSTI)

to BIP/FSCC's RESET to (NIM) test output FSCC/COM (NIM) INPUT TRIGGER GLOBAL 0.08­19.5 usec adjustable

Berns, Hans-Gerd

444

Test | Open Energy Information  

Open Energy Info (EERE)

Jump to: navigation, search This should be in several categories Retrieved from "http:en.openei.orgwindex.php?titleTest&oldid643989" Category: RecipePage...

445

Feature - Testing the Tesla  

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

Testing the Tesla Testing the Tesla Tesla test Technician Geoff Amann takes the Tesla.through a driving cycle on Argonne's dynamometers. Argonne transportation engineers recently evaluated an all-electric Tesla Roadster at the Advanced Powertrain Research Facility's new two-wheel drive dynamometer laboratory. Data obtained from the Tesla will help researchers develop test procedures that provide an unbiased, consistent and practical approach to evaluating electric vehicles. "As we study these advanced vehicles, our knowledge base of the progression of vehicle electrification technology is enhanced," said chief engineer Mike Duoba. "In a rigorous, controlled manner, we are able to study many vehicle operating conditions to determine the impact on fuel consumption.

446

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

447

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

448

An Environmental Assessment of Proposed Geothermal Well Testing in the Tigre Lagoon Oil Field, Vermilion Parish, Louisiana  

DOE Green Energy (OSTI)

This report is an environmental assessment of the proposed testing of two geopressured, geothermal aquifers in central coastal Louisiana. On the basis of an analysis of the environmental setting, subsurface characteristics, and the proposed action, potential environmental impacts are determined and evaluated together with potential conflicts with federal, state, and local programs. Oil and gas wells in coastal Louisiana have penetrated a potentially productive geothermal zone of abnormally high-pressured aquifers that also yield large volumes of natural gas. To evaluate the extent to which the geothermal-geopressured water can be used as an alternative energy source and to what extent withdrawal of geopressured water can enhance gas production, it is necessary that flow rates, composition and temperature of fluids and gases, recharge characteristics, pressures, compressibilities, and other hydrodynamic and boundary conditions of the reservoir be determined by means of production tests. Tests are further necessary to evaluate and seek solutions to technological problems.

None

1976-03-01T23:59:59.000Z

449

Faster mutation testing inspired by test prioritization and reduction  

Science Conference Proceedings (OSTI)

Mutation testing is a well-known but costly approach for determining test adequacy. The central idea behind the approach is to generate mutants, which are small syntactic transformations of the program under test, and then to measure for a given test ... Keywords: Mutation testing, Test Prioritization, Test Reduction

Lingming Zhang, Darko Marinov, Sarfraz Khurshid

2013-07-01T23:59:59.000Z

450

High Stakes: Testing Irregularity  

Science Conference Proceedings (OSTI)

With the No Child Left Behind Act of 2001, a stronger emphasis has been placed on state testing and accountability at the state and local levels. The news media continues to report testing irregularities as professional and community pressures are levied ...

Tricia Carson-Meyers; Edye Morris Bryant; Fredrick Thomas; Kenneth H. Brinson, Jr.

2005-03-01T23:59:59.000Z

451

Coaxial test fixture  

DOE Patents (OSTI)

An assembly is provided for testing one or more contact material samples in a vacuum environment. The samples are positioned as an inner conductive cylinder assembly which is mounted for reciprocal vertical motion as well as deflection from a vertical axis. An outer conductive cylinder is coaxially positioned around the inner cylinder and test specimen to provide a vacuum enclosure therefor. A power source needed to drive test currents through the test specimens is connected to the bottom of each conductive cylinder, through two specially formed conductive plates. The plates are similar in form, having a plurality of equal resistance current paths connecting the power source to a central connecting ring. The connecting rings are secured to the bottom of the inner conductive assembly and the outer cylinder, respectively. A hydraulic actuator is also connected to the bottom of the inner conductor assembly to adjust the pressure applied to the test specimens during testing. The test assembly controls magnetic forces such that the current distribution through the test samples is symmetrical and that contact pressure is not reduced or otherwise disturbed.

Praeg, Walter F. (Palos Park, IL)

1986-01-01T23:59:59.000Z

452

RMOTC - Testing - Exploration  

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

Exploration Helicopter flying over RMOTC testing facility for leak detection survey test Notice: As of July 15th 2013, the Department of Energy announced the intent to sell Naval Petroleum Reserve Number 3 (NPR3). The sale of NPR-3 will also include the sale of all equipment and materials onsite. A decision has been made by the Department of Energy to complete testing at RMOTC by July 1st, 2014. RMOTC will complete testing in the coming year with the currently scheduled testing partners. For more information on the sale of NPR-3 and sale of RMOTC equipment and materials please join our mailing list here. RMOTC's extensive exploration-related data sets, including 3D and 2D seismic, wells and logging data, and cores - both physical core samples, stored in Casper, and core analysis data and reports - provide a great

453

RMOTC - Testing - Alternative Energies  

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

Alternative Energies Alternative Energies Wind turbine at RMOTC field test site Notice: As of July 15th 2013, the Department of Energy announced the intent to sell Naval Petroleum Reserve Number 3 (NPR3). The sale of NPR-3 will also include the sale of all equipment and materials onsite. A decision has been made by the Department of Energy to complete testing at RMOTC by July 1st, 2014. RMOTC will complete testing in the coming year with the currently scheduled testing partners. For more information on the sale of NPR-3 and sale of RMOTC equipment and materials please join our mailing list here. RMOTC provides the opportunity for its partners to field test the latest alternative energy and environmental management technologies which have specific and beneficial application in oil fields, remote sites, and

454

RMOTC - Testing - Flow Assurance  

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

Flow Assurance Flow Assurance RMOTC Flow Loop Facility Layout Notice: As of July 15th 2013, the Department of Energy announced the intent to sell Naval Petroleum Reserve Number 3 (NPR3). The sale of NPR-3 will also include the sale of all equipment and materials onsite. A decision has been made by the Department of Energy to complete testing at RMOTC by July 1st, 2014. RMOTC will complete testing in the coming year with the currently scheduled testing partners. For more information on the sale of NPR-3 and sale of RMOTC equipment and materials please join our mailing list here. Over a decade ago, RMOTC began cooperatively building a full-scale facility to test new flow assurance technology, mainly in the areas of hydrates and paraffins. Today, RMOTC's test facility consists of five individual loop

455

Undulator Transportation Test Results  

SciTech Connect

A test was performed to determine whether transporting and handling the undulators makes any changes to their properties. This note documents the test. No significant changes to the test undulator were observed. After the LCLS undulators are tuned and fiducialized in the Magnetic Measurement Facility (MMF), they must be transported to storage buildings and transported to the tunnel. It has been established that the undulators are sensitive to temperature. We wish to know whether the undulators are also sensitive to the vibrations and shocks of transportation. To study this issue, we performed a test in which an undulator was measured in the MMF, transported to the tunnel, brought back to the MMF, and re-measured. This note documents the test and the results.

Wolf, Zachary

2010-11-17T23:59:59.000Z

456

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

457

Bad pairs in software testing  

Science Conference Proceedings (OSTI)

With pairwise testing, the test model is a list of N parameters. Each test case is an N-tuple; the test space is the cross product of the N parameters. A pairwise test is a set of N-tuples where every pairwise combination ... Keywords: covering and error-locating arrays, pairwise testing, software testing

Daniel Hoffman; Chien-Hsing Chang; Gary Bazdell; Brett Stevens; Kevin Yoo

2010-09-01T23:59:59.000Z

458

Analyzing Regression Test Selection Techniques  

Science Conference Proceedings (OSTI)

AbstractRegression testing is a necessary but expensive maintenance activity aimed at showing that code has not been adversely affected by changes. Regression test selection techniques reuse tests from an existing test suite to test a modified program. ... Keywords: Software maintenance, regression testing, selective retest, regression test selection.

Gregg Rothermel; Mary Jean Harrold

1996-08-01T23:59:59.000Z

459