Dual Axis Radiographic Hydrodynamic Test Facility | National...
National Nuclear Security Administration (NNSA)
Dual Axis Radiographic Hydrodynamic Test Facility An integral part of the national ... radiographic images of the imploding test object, in which materials are moving at ...
DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility
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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...
DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT: Dual-Axis Radiographic Hydrodynamic Test Facility DARHT, 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,
EIS-0228: Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility
Broader source: Energy.gov [DOE]
This EIS evaluates the potential environmental impact of a proposal to construct and operate the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory (LANL)...
Dual Axis Radiographic Hydrodynamic Test | National Nuclear Security
National Nuclear Security Administration (NNSA)
Administration Dual Axis Radiographic Hydrodynamic Test NNSA releases Stockpile Stewardship Program quarterly experiments summary WASHIGTON, DC. - The National Nuclear Security Administration today released its current quarterly summary of experiments conducted as part of its science-based Stockpile Stewardship Program. The experiments carried out within the program are used in combination with complex computational models
Dual Axis Radiographic Hydrodynamic Test Facility
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
DARHT 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
Dual Axis Radiographic Hydrodynamic Test Facility | National Nuclear
National Nuclear Security Administration (NNSA)
Security Administration | (NNSA) Dual Axis Radiographic Hydrodynamic Test Facility An integral part of the national hydrotest 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 powerful electron beam that is focused onto a metal target which converts the kinetic energy of the electron beam into high energy x or gamma-rays. The x-ray dose from one DARHT accelerator is
Dual Axis Radiographic Hydrodynamic Test Facility mitigation action plan. Annual report for 1998
Haagenstad, T.
1999-01-15
This Mitigation Action Plan Annual Report (MAPAR) has been prepared as part of implementing the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Mitigation Action Plan (MAP) to protect workers, soils, water, and biotic and cultural resources in and around the facility.
1995-08-01
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.
Dual Axis Radiographic Hydrodynamic Test Facility mitigation action plan. Annual report for 1997
Haagenstad, H.T.
1998-01-15
This Mitigation Action Plan Annual Report (MAPAR) has been prepared by the US Department of Energy (DOE) as part of implementing the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Mitigation Action Plan (MAP). This MAPAR provides a status on specific DARHT facility design- and construction-related mitigation actions that have been initiated in order to fulfill DOE`s commitments under the DARHT MAP. The functions of the DARHT MAP are to (1) document potentially adverse environmental impacts of the Phased Containment Option delineated in the Final EIS, (2) identify commitments made in the Final EIS and ROD to mitigate those potential impacts, and (3) establish Action Plans to carry out each commitment (DOE 1996). The DARHT MAP is divided into eight sections. Sections 1--5 provide background information regarding the NEPA review of the DARHT project and an introduction to the associated MAP. Section 6 references the Mitigation Action Summary Table which summaries the potential impacts and mitigation measures; indicates whether the mitigation is design-, construction-, or operational-related; the organization responsible for the mitigation measure; and the projected or actual completion data for each mitigation measure. Sections 7 and 8 discuss the Mitigation Action Plan Annual Report and Tracking System commitment and the Potential Impacts, Commitments, and Action Plans respectively. Under Section 8, potential impacts are categorized into five areas of concern: General Environment, including impacts to air and water; Soils, especially impacts affecting soil loss and contamination; Biotic Resources, especially impacts affecting threatened and endangered species; Cultural/Paleontological Resources, especially impacts affecting the archeological site known as Nake`muu; and Human Health and Safety, especially impacts pertaining to noise and radiation. Each potential impact includes a brief statement of the nature of the impact and its cause(s). The commitment
Hydrodynamic Testing Facilities Database | Open Energy Information
Hydrodynamic Testing Facilities Database (Redirected from Hydrodynamic Testing Facilities) Jump to: navigation, search Facility Operators By viewing Hydrodynamic Testing Facilities...
Hydrodynamic Testing Facilities Database | Open Energy Information
Hydrodynamic Testing Facilities Database Jump to: navigation, search Facility Operators By viewing Hydrodynamic Testing Facilities in the list accompanying the map, one will be...
A proposed benchmark for simulation in radiographic testing
Jaenisch, G.-R.; Deresch, A.; Bellon, C.; Schumm, A.; Guerin, P.
2014-02-18
The purpose of this benchmark study is to compare simulation results predicted by various models of radiographic testing, in particular those that are capable of separately predicting primary and scatter radiation for specimens of arbitrary geometry.
Measuring x-ray spectra of flash radiographic sources
Gehring, Amanda Elizabeth; Espy, Michelle A.; Haines, Todd Joseph; Mendez, Jacob; Moir, David C.; Sedillo, Robert; Shurter, Roger P.; Volegov, Petr Lvovich; Webb, Timothy J
2015-11-02
The x-ray spectra of flash radiographic sources is difficult to measure. The sources measured were Radiographic Integrated Test Stand-6 (370 rad at 1 m; 50 ns pulse) and Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) (550 rad at 1 m; 50 ns pulse). Features of the Compton spectrometer are described, and spectra are shown. Additional slides present data on instrumental calibration.
Development and Implementation of Radiation-Hydrodynamics Verification Test Problems
Marcath, Matthew J.; Wang, Matthew Y.; Ramsey, Scott D.
2012-08-22
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.
Radiation Hydrodynamics Test Problems with Linear Velocity Profiles
Hendon, Raymond C.; Ramsey, Scott D.
2012-08-22
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.
A class of self-similar hydrodynamics test problems
Ramsey, Scott D; Brown, Lowell S; Nelson, Eric M; Alme, Marv L
2010-12-08
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.
Pennsylvania State University Hydrodynamics | Open Energy Information
State University Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Pennsylvania State University Address Applied Research Laboratory, Garfield...
University of Minnesota Hydrodynamics | Open Energy Information
Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of Minnesota Address St. Anthony Falls Laboratory, 2 Third Avenue SE Place...
University of Michigan Hydrodynamics | Open Energy Information
Michigan Hydrodynamics Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name University of Michigan Address 1085 South University Avenue Place Ann Arbor,...
Follow-up on the Los Alamos National Laboratory Hydrodynamic...
Broader source: Energy.gov (indexed) [DOE]
Follow-up on the Los Alamos National Laboratory Hydrodynamic Test Program DOEIG-0930 ... Alamos National Laboratory Hydrodynamic Test Program" BACKGROUND A primary mission of ...
Radiographic Inspection of Fueled Clads
Timothy J. Roney; Karen M. Wendt
2005-04-01
Five general purpose heat source (GPHS) fueled clads were radiographically inspected at the Idaho National Laboratory (INL). The girth weld region of each clad had previously passed visual examination, ring gauge test, and leak test but showed “positive” indications on the ultrasonic (UT) test. Positive ultrasonic indications are allowable under certain weld conditions; radiographic inspection provides a secondary nonintrusive means of clad inspection and may confirm allowable anomalies from the UT inspection. All the positive UT indications were found to exhibit allowable weld shield fusion or mismatch conditions. No indication of void defects was found. One additional clad (FCO371) was deemed unacceptable for radiographic inspection due to an unknown black substance that obscured the angular origin on the weld so that the angular offset to the UT indication could not be found.
Facilities | National Nuclear Security Administration | (NNSA...
National Nuclear Security Administration (NNSA)
Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility, Los Alamos National ... Dual Axis Radiographic Hydrodynamic Test Facility High Explosives Application ...
Annual Report: Hydrodynamics and Radiative Hydrodynamics with Astrophysical Applications
R. Paul Drake
2005-12-01
We report the ongoing work of our group in hydrodynamics and radiative hydrodynamics with astrophysical applications. During the period of the existing grant, we have carried out two types of experiments at the Omega laser. One set of experiments has studied radiatively collapsing shocks, obtaining high-quality scaling data using a backlit pinhole and obtaining the first (ever, anywhere) Thomson-scattering data from a radiative shock. Other experiments have studied the deeply nonlinear development of the Rayleigh-Taylor (RT) instability from complex initial conditions, obtaining the first (ever, anywhere) dual-axis radiographic data using backlit pinholes and ungated detectors. All these experiments have applications to astrophysics, discussed in the corresponding papers either in print or in preparation. We also have obtained preliminary radiographs of experimental targets using our x-ray source. The targets for the experiments have been assembled at Michigan, where we also prepare many of the simple components. The above activities, in addition to a variety of data analysis and design projects, provide good experience for graduate and undergraduates students. In the process of doing this research we have built a research group that uses such work to train junior scientists.
Colorado State University Hydrodynamics | Open Energy Information
Jump to: navigation, search Hydro | Hydrodynamic Testing Facilities Name Colorado State University Address Daryl B. Simons Building, Engineering Research Center, 1320 Campus...
University of Maine Hydrodynamics | Open Energy Information
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...
Oregon State University Hydrodynamics | Open Energy Information
search Hydro | Hydrodynamic Testing Facilities Name Oregon State University Address O.H. Hinsdale Wave Research Laboratory, 220 Owen Hall Place Corvallis, Oregon Zip 97331...
Sandia National Laboratories Hydrodynamics | Open Energy Information
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...
Diode magnetic-field influence on radiographic spot size
Ekdahl, Carl A. Jr.
2012-09-04
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
Los Alamos conducts important hydrodynamic experiment in Nevada
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
nuclear testing," said Webster. These experiments with surrogate materials provide a principle linkage with scaledfull-scale hydrodynamic tests, the suite of prior underground...
Hydrodynamic effects on coalescence. (Technical Report) | SciTech...
Office of Scientific and Technical Information (OSTI)
The goal of this project was to design, build and test novel diagnostics to probe the ... Subject: 42 ENGINEERING; DROPLETS; COALESCENCE; HYDRODYNAMICS; TEST FACILITIES; DESIGN; ...
Najjar, F M; Solberg, J; White, D
2008-04-17
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.
University of New Hampshire Hydrodynamics | Open Energy Information
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...
Hydrodynamic experiment provides key data for Stockpile Stewardship
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
weapon performance in the absence of full-scale underground nuclear testing," said Webster. Los Alamos hydrodynamic experiment provides key data for Stockpile Stewardship In...
Film holder for radiographing tubing
Davis, Earl V.; Foster, Billy E.
1976-01-01
A film cassette is provided which may be easily placed about tubing or piping and readily held in place while radiographic inspection is performed. A pair of precurved light-impervious semi-rigid plastic sheets, hinged at one edge, enclose sheet film together with any metallic foils or screens. Other edges are made light-tight with removable caps, and the entire unit is held securely about the object to be radiographed with a releasable fastener such as a strip of Velcro.
Microsoft Word - Defense Science Quarterly 08-08.doc
National Nuclear Security Administration (NNSA)
6 Dual Axis Radiographic Hydrodynamics Test (DARHT) 2 nd Axis Completed and Put into ... Another big facility at LANL is the Dual Axis Radiographic Hydrodynamics Test (DARHT), and ...
National Nuclear Security Administration (NNSA)
1 2.1 Dual-Axis Radiographic Hydrodynamic Test Facility Mitigation Action Plan (Appendix ... II Dual Axis Radiographic Hydrodynamic Test Facility Mitigation Action Plan Annual ...
Hydrodynamics from Landau initial conditions
Sen, Abhisek; Gerhard, Jochen; Torrieri, Giorgio; Read jr, Kenneth F.; Wong, Cheuk-Yin
2015-01-01
We investigate ideal hydrodynamic evolution, with Landau initial conditions, both in a semi-analytical 1+1D approach and in a numerical code incorporating event-by-event variation with many events and transverse density inhomogeneities. The object of the calculation is to test how fast would a Landau initial condition transition to a commonly used boost-invariant expansion. We show that the transition to boost-invariant flow occurs too late for realistic setups, with corrections of O (20 - 30%) expected at freezeout for most scenarios. Moreover, the deviation from boost-invariance is correlated with both transverse flow and elliptic flow, with the more highly transversely flowing regions also showing the most violation of boost invariance. Therefore, if longitudinal flow is not fully developed at the early stages of heavy ion collisions, 2+1 dimensional hydrodynamics is inadequate to extract transport coefficients of the quark-gluon plasma. Based on [1, 2
Skew resisting hydrodynamic seal
Conroy, William T.; Dietle, Lannie L.; Gobeli, Jeffrey D.; Kalsi, Manmohan S.
2001-01-01
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.
Livermore Unstructured Lagrange Explicit Shock Hydrodynamics
Energy Science and Technology Software Center (OSTI)
2010-09-21
LULESH v1.0 is a 3D unstructured Lagrange hydrodynamics simulation written specifically to solve a standard analytical test problem, known as the Sedov problem. In this problem, a quantum of energy is deposited into a gas and propagates through the gas over time.
Blaedel, Kenneth L.; Davis, Pete J.; Landram, Charles S.
2000-01-01
A saw having a self-pumped hydrodynamic blade guide or bearing for retaining the saw blade in a centered position in the saw kerf (width of cut made by the saw). The hydrodynamic blade guide or bearing utilizes pockets or grooves incorporated into the sides of the blade. The saw kerf in the workpiece provides the guide or bearing stator surface. Both sides of the blade entrain cutting fluid as the blade enters the kerf in the workpiece, and the trapped fluid provides pressure between the blade and the workpiece as an inverse function of the gap between the blade surface and the workpiece surface. If the blade wanders from the center of the kerf, then one gap will increase and one gap will decrease and the consequent pressure difference between the two sides of the blade will cause the blade to re-center itself in the kerf. Saws using the hydrodynamic blade guide or bearing have particular application in slicing slabs from boules of single crystal materials, for example, as well as for cutting other difficult to saw materials such as ceramics, glass, and brittle composite materials.
Load responsive hydrodynamic bearing
Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.
2002-01-01
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.
advanced radiographic capability | National Nuclear Security Administration
National Nuclear Security Administration (NNSA)
advanced radiographic capability ARC will make tiny "movies" of thermonuclear and stockpile experiments The National Ignition Facility's (NIF) performed the first programmatic experiments with Advanced Radiographic Capability (ARC) on December 1-3, 2015. ARC, a petawatt-class laser with peak power that will exceed a quadrillion watts, is designed to produce brighter, more penetrating, higher-energy
Neep, Michael J; Steffens, Tom; Owen, Rebecca; McPhail, Steven M
2014-06-15
The provision of a written comment on traumatic abnormalities of the musculoskeletal system detected by radiographers can assist referrers and may improve patient management, but the practice has not been widely adopted outside the United Kingdom. The purpose of this study was to investigate Australian radiographers' perceptions of their readiness for practice in a radiographer commenting system and their educational preferences in relation to two different delivery formats of image interpretation education, intensive and non-intensive. A cross-sectional web-based questionnaire was implemented between August and September 2012. Participants included radiographers with experience working in emergency settings at four Australian metropolitan hospitals. Conventional descriptive statistics, frequency histograms, and thematic analysis were undertaken. A Wilcoxon signed-rank test examined whether a difference in preference ratings between intensive and non-intensive education delivery was evident. The questionnaire was completed by 73 radiographers (68% response rate). Radiographers reported higher confidence and self-perceived accuracy to detect traumatic abnormalities than to describe traumatic abnormalities of the musculoskeletal system. Radiographers frequently reported high desirability ratings for both the intensive and the non-intensive education delivery, no difference in desirability ratings for these two formats was evident (z = 1.66, P = 0.11). Some Australian radiographers perceive they are not ready to practise in a frontline radiographer commenting system. Overall, radiographers indicated mixed preferences for image interpretation education delivered via intensive and non-intensive formats. Further research, preferably randomised trials, investigating the effectiveness of intensive and non-intensive education formats of image interpretation education for radiographers is warranted.
NNSA, LANL Complete DARHT Improvements With Successful Multi...
National Nuclear Security Administration (NNSA)
NNSA, LANL Complete DARHT Improvements With Successful Multi-frame Hydrodynamic Test ... (LANL) Dual Axis Radiographic Hydrodynamic Test (DARHT) facility has completed another ...
EIS-0228: Record of Decision | Department of Energy
Office of Environmental Management (EM)
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) ...
Iterative Reconstruction of Coded Source Neutron Radiographs
Santos-Villalobos, Hector J; Bingham, Philip R; Gregor, Jens
2012-01-01
Use of a coded source facilitates high-resolution neutron imaging but requires that the radiographic data be deconvolved. In this paper, we compare direct deconvolution with two different iterative algorithms, namely, one based on direct deconvolution embedded in an MLE-like framework and one based on a geometric model of the neutron beam and a least squares formulation of the inverse imaging problem.
A Radiographic Technique With Heavy Ion Microbeams
Muscio, J.; Somacal, H.; Burlon, A. A.; Debray, M. E.; Valda, A. A.; Kreiner, A. J.; Kesque, J. M.; Minsky, D. M.
2007-02-12
In this work, we introduce a new technique to perform densitometric and multielemental analysis of samples at the same time using a simple detector with heavy ion micro-beams. It consists in the simultaneous analysis of X-rays induced in the sample and in a secondary target arranged behind the specimen. The X-rays originated in the secondary target are attenuated when crossing the specimen producing a radiographic image with a monochromatic source.
Disruptive Innovation in Numerical Hydrodynamics
Waltz, Jacob I.
2012-09-06
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.
Laser driven hydrodynamic instability experiments
Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.
1992-12-07
We have conducted an extensive series of experiments on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime; multimode foils allow an assessment of the degree of mode coupling; and surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes. Experimental results and comparisons with theory and simulations are presented.
Foundation of Hydrodynamics of Strongly Interacting Systems
Wong, Cheuk-Yin
2014-01-01
Hydrodynamics and quantum mechanics have many elements in common, as the density field and velocity fields are common variables that can be constructed in both descriptions. Starting with the Schroedinger equation and the Klein-Gordon for a single particle in hydrodynamical form, we examine the basic assumptions under which a quantum system of particles interacting through their mean fields can be described by hydrodynamics.
COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC...
Office of Scientific and Technical Information (OSTI)
Title: COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC RESPONSE IN SOLAR FLARES. I. THE NUMERICAL MODEL Acceleration and transport of high-energy particles and fluid ...
A Two-Dimensional Radiation Hydrodynamics Code
Energy Science and Technology Software Center (OSTI)
2003-03-10
Calculation of compressible and high energetic hydrodynamic fields including photon transport and heat conduction in twodimensional curvilinear geometry.
Effects on the Physical Environment (Hydrodynamics, Sediment...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Sediment Transport, and Water Quality) Effects on the Physical Environment (Hydrodynamics, ... Development 2014 Water Power Program Peer Review Compiled Presentations: Marine and ...
Hydromechanical transmission with hydrodynamic drive
Orshansky, Jr., deceased, Elias; Weseloh, William E.
1979-01-01
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.
Hydrodynamic enhanced dielectrophoretic particle trapping
Miles, Robin R.
2003-12-09
Hydrodynamic enhanced dielectrophoretic particle trapping carried out by introducing a side stream into the main stream to squeeze the fluid containing particles close to the electrodes producing the dielelectrophoretic forces. The region of most effective or the strongest forces in the manipulating fields of the electrodes producing the dielectrophoretic forces is close to the electrodes, within 100 .mu.m from the electrodes. The particle trapping arrangement uses a series of electrodes with an AC field placed between pairs of electrodes, which causes trapping of particles along the edges of the electrodes. By forcing an incoming flow stream containing cells and DNA, for example, close to the electrodes using another flow stream improves the efficiency of the DNA trapping.
Stephan, Carl N.; Amidan, Brett G.; Trease, Harold E.; Guyomarch, Pierre; Pulsipher, Trenton C.; Byrd, John E.
2014-03-01
This paper describes a computerized clavicle identification system, primarily designed to resolve the identities of unaccounted for US soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero-anterior antemortem chest radiographs to rank individuals in terms of metric distance. Similar to leading fingerprint identification systems, shortlists of the top matching candidates are extracted for subsequent human visual assessment. Two independent tests of the computerized system using 17 field-recovered skeletons and 409 chest radiographs demonstrate that true positive matches are captured within the top 5% of the sample 75% of the time. These results are outstanding given the eroded state of some field-recovered skeletons and the faintness of the 1950’s photoflurographs. These methods enhance the capability to resolve several hundred cold cases for which little circumstantial information exists and current DNA and dental record technologies cannot be applied.
Damaged Surface Hydrodynamics (DSH) Flash Report (Technical Report...
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Technical Report: Damaged Surface Hydrodynamics (DSH) Flash Report Citation Details In-Document Search Title: Damaged Surface Hydrodynamics (DSH) Flash Report You are accessing ...
Effects on the Physical Environment (Hydrodynamics, and Water...
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and Water Quality Food Web) Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web) Effects on the Physical Environment (Hydrodynamics, and Water Quality ...
Tidal Energy Test Platform | Open Energy Information
Test Platform Jump to: navigation, search Basic Specifications Facility Name Tidal Energy Test Platform Overseeing Organization University of New Hampshire Hydrodynamics...
Radiograph and passive data analysis using mixed variable optimization...
Office of Scientific and Technical Information (OSTI)
In this embodiment, the computer is configured to input the radiographic image data from the two-dimensional detector and to determine one or more materials that form the object by ...
Seawater magnetohydrodynamic test apparatus
Meng, J.
1993-02-11
Accordingly, it is an object of the present invention to provide a hydrodynamic test facility suitable for low turbulence and low radiated noise experiments. It is another object to provide a hydrodynamic test facility having no moving parts in the water flow path. It is yet another to provide a hydrodynamic test facility having a water flow powered by a magnetohydrodynamic pump. Accordingly, the invention is a hydrodynamic test facility using a magnetohydrodynamic (MHD) drive unit to provide the force necessary to circulate water in the test loop section. The test loop is fed by water from a pretreatment section which mixes seawater and tapwater to provide the desired salinity. A post-treatment section neutralizes emitted chlorine gases.
RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code
Zhang, Wei-Qun; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study
2005-06-06
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.
Stabilizing geometry for hydrodynamic rotary seals
Dietle, Lannie L.; Schroeder, John E.
2010-08-10
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.
Effects of Second-Order Hydrodynamics on a Semisubmersible Floating Offshore Wind Turbine: Preprint
Bayati, I.; Jonkman, J.; Robertson, A.; Platt, A.
2014-07-01
The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of the system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the MARIN offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST in the future. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method has been applied to the OC4-DeepCwind semisubmersible platform, supporting the NREL 5-MW baseline wind turbine. The loads and response of the system due to the second-order hydrodynamics are analysed and compared to first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second-order loads and induced response data are compared to the loads and motions induced by aerodynamic loading as solved by FAST.
Hydrodynamic experiment provides key data for Stockpile Stewardship
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Hydrodynamic experiment provides Stockpile Stewardship key data Los Alamos hydrodynamic experiment provides key data for Stockpile Stewardship Hydrodynamic experiments such as Leda involve non-nuclear surrogate materials that mimic many of the properties of nuclear materials. December 22, 2014 Los Alamos hydrodynamic experiment provides key data for Stockpile Stewardship "Leda," experimental vessel in the "Zero Room" at the underground U1a facility, at the Nevada National
Survey of Multi-Material Closure Models in 1D Lagrangian Hydrodynamics
Maeng, Jungyeoul Brad; Hyde, David Andrew Bulloch
2015-07-28
Accurately treating the coupled sub-cell thermodynamics of computational cells containing multiple materials is an inevitable problem in hydrodynamics simulations, whether due to initial configurations or evolutions of the materials and computational mesh. When solving the hydrodynamics equations within a multi-material cell, we make the assumption of a single velocity field for the entire computational domain, which necessitates the addition of a closure model to attempt to resolve the behavior of the multi-material cells’ constituents. In conjunction with a 1D Lagrangian hydrodynamics code, we present a variety of both the popular as well as more recently proposed multi-material closure models and survey their performances across a spectrum of examples. We consider standard verification tests as well as practical examples using combinations of fluid, solid, and composite constituents within multi-material mixtures. Our survey provides insights into the advantages and disadvantages of various multi-material closure models in different problem configurations.
NNSA releases Stockpile Stewardship Program quarterly experiments...
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the Dual Axis Radiographic Hydrodynamic Test facility at Los Alamos National ... All of the NNSA research, development, test, and evaluation experimental facilities are ...
Proton Radiography at LANL | U.S. DOE Office of Science (SC)
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is the Dual-Axis Radiographic Hydrodynamic Test facility, or DARHT. Recently completed at ... of proton radiography's ability to measure small density differences inside a test object. ...
Microsoft Word - newletter August 2007 v5.doc
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3 Dual Axis Radiographic Hydrodynamics Test (DARHT) 2 nd Axis Achieves Full ... between the laboratories, the Nevada Test Site, and other DOENNSA organizations. ...
Research and Development | National Nuclear Security Administration...
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Research, Development, Test, and Evaluation Research and Development Photo: DARHT's ... as the Dual Axis Radiographic Hydrodynamic Test Facility (DARHT), Site 300, Z, Nevada ...
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The Dual Axis Radiographic Hydrodynamic Test facility really demonstrated what an ... experiment is to test the predictions for the initial conditions of primary implosion. ...
New finding in the radiographic diagnosis of Achilles tendon rupture
Newmark, H.; Mellon, W.S. Jr.; Malhotra, A.K.; Olken, S.M.; Halls, J.
1982-06-01
The authors describe a new radiographic sign of rupture of the Achilles tendon system. It is a fracture, with separation through an osteophyte at the insertion of this tendon. Previously reported signs are also discussed as well as the present case report.
PHERMEX: pulsed high energy radiographic machine emitting x-rays
Dick, R.D.
1983-01-01
The PHERMEX facility used to provide flash radiographs of explosives and explosive-driven metal systems is described. With this facility, precision radiographs of large objects containing materials with high atomic number and high density are attainable. PHERMEX encompass the high-current, three-cavity, 30-MeV linear electron accelerator; the 50-MHz radio-frequency power source to drive the cavities; timing, and signal detection system; and a data-acquisition system. Some unique features of PHERMEX are reliability; very intense sub-microsecond bremsstrahlung source rich in 4- to 8-MeV x rays; less than 1.0-mm-diam spot size; precision determination of edges, discontinuities, and areal-mass distribution; and flash radiographs of large explosive systems close to the x-ray target. Some aspects of the PHERMEX-upgrading program are discussed. The program will result in (1) an increased electron-beam energy to about 50 MeV, (2) the use of an electron-gun pulser that is capable of producing three-time-adjustable pulses for obtaining three radiographic pictures of a single explosive event, (3) an increased electron injection energy of 1.25 MeV, (4) the capability for recording high-speed signals, and (5) the use of computers to assist the monitoring and control of the data-acquisition system and the PHERMEX accelerator.
PHERMEX: Pulsed High-Energy Radiographic Machine Emitting X rays
Dick, R.D.
1981-01-01
The PHERMEX facility used to provide flash radiographs of explosives and explosive-driven metal systems is described. With this facility, precision radiographs of large objects containing materials with high atomic number and high density are attainable. PHERMEX encompasses the high-current, three-cavity, 30-MeV linear electron accelerator; the 50-MHz-radiofrequency power source to drive the cavities; timing, firing, and signal detection system; and a data-acquisition system. Some unique features of PHERMEX are reliability; very intensive submicrosecond bremsstrahlung source rich in 4- to 8-MeV x rays; less than 1.0-mm-diam spot size; precision determination of edges, discontinuities, and areal-mass distribution; and flash radiographs of large explosive systems close to the x-ray target. Some aspects of the PHERMEX-upgrading program are discussed. The program will result (1) in an increased electron-beam energy to about 50 MeV, (2) the use of an electron-gun pulser that is capable of producing three time-adjustable pulses for obtaining three radiographic pictures of a single explosive event, (3) an increased electron injection energy of 1.25 MeV, (4) the capability for recording high-speed signals, and (5) the use of computers to assist the monitoring and control of the data-acquisition system and the PHERMEX accelerator.
CHARACTERIZATION OF THE ADVANCED RADIOGRAPHIC CAPABILITY FRONT END ON NIF
Haefner, C; Heebner, J; Dawson, J; Fochs, S; Shverdin, M; Crane, J K; Kanz, V K; Halpin, J; Phan, H; Sigurdsson, R; Brewer, W; Britten, J; Brunton, G; Clark, W; Messerly, M J; Nissen, J D; Nguyen, H; Shaw, B; Hackel, R; Hermann, M; Tietbohl, G; Siders, C W; Barty, C J
2009-07-15
We have characterized the Advanced Radiographic Capability injection laser system and demonstrated that it meets performance requirements for upcoming National Ignition Facility fusion experiments. Pulse compression was achieved with a scaled down replica of the meter-scale grating ARC compressor and sub-ps pulse duration was demonstrated at the Joule-level.
RELIABLE RADIOGRAPHIC INSPECTION OF FLEXIBLE RISERS FOR THE OIL INDUSTRY
Almeida, Romulo M.; Rebello, Joao Marcos A. [Department of Metallurgical and Materials Engineering COPPE/UFRJ-Federal University of Rio de Janeiro P.O. Box 68505 CEP 21941-972, Rio de Janeiro RJ (Brazil); Vaz, Murilo A. [Department of Ocean Engineering-COPPE/UFRJ (Brazil)
2010-02-22
Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.
Novel techniques for slurry bubble column hydrodynamics
Dudukovic, M.P.
1999-05-14
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.
Laser-driven hydrodynamic instability experiments
Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K. )
1993-07-01
An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single-mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils give a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes.
Laser driven hydrodynamic instability experiments. Revision 1
Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.
1993-02-17
An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes.
Property:Hydrodynamic Testing Facility Type | Open Energy Information
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...
Category:Hydrodynamic Testing Facility Type | Open Energy Information
out of 9 total. C Channel F Flow Table Flume O Offshore Berth R Reverberant Tank T Tow Tank T cont. Tow Vessel Tunnel W Wave Basin Retrieved from "http:en.openei.orgw...
Radiograph and passive data analysis using mixed variable optimization
Temple, Brian A.; Armstrong, Jerawan C.; Buescher, Kevin L.; Favorite, Jeffrey A.
2015-06-02
Disclosed herein are representative embodiments of methods, apparatus, and systems for performing radiography analysis. For example, certain embodiments perform radiographic analysis using mixed variable computation techniques. One exemplary system comprises a radiation source, a two-dimensional detector for detecting radiation transmitted through a object between the radiation source and detector, and a computer. In this embodiment, the computer is configured to input the radiographic image data from the two-dimensional detector and to determine one or more materials that form the object by using an iterative analysis technique that selects the one or more materials from hierarchically arranged solution spaces of discrete material possibilities and selects the layer interfaces from the optimization of the continuous interface data.
A Bayesian Measurment Error Model for Misaligned Radiographic Data
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lennox, Kristin P.; Glascoe, Lee G.
2013-09-06
An understanding of the inherent variability in micro-computed tomography (micro-CT) data is essential to tasks such as statistical process control and the validation of radiographic simulation tools. The data present unique challenges to variability analysis due to the relatively low resolution of radiographs, and also due to minor variations from run to run which can result in misalignment or magnification changes between repeated measurements of a sample. Positioning changes artificially inflate the variability of the data in ways that mask true physical phenomena. We present a novel Bayesian nonparametric regression model that incorporates both additive and multiplicative measurement error inmore » addition to heteroscedasticity to address this problem. We also use this model to assess the effects of sample thickness and sample position on measurement variability for an aluminum specimen. Supplementary materials for this article are available online.« less
A Bayesian Measurment Error Model for Misaligned Radiographic Data
Lennox, Kristin P.; Glascoe, Lee G.
2013-09-06
An understanding of the inherent variability in micro-computed tomography (micro-CT) data is essential to tasks such as statistical process control and the validation of radiographic simulation tools. The data present unique challenges to variability analysis due to the relatively low resolution of radiographs, and also due to minor variations from run to run which can result in misalignment or magnification changes between repeated measurements of a sample. Positioning changes artificially inflate the variability of the data in ways that mask true physical phenomena. We present a novel Bayesian nonparametric regression model that incorporates both additive and multiplicative measurement error in addition to heteroscedasticity to address this problem. We also use this model to assess the effects of sample thickness and sample position on measurement variability for an aluminum specimen. Supplementary materials for this article are available online.
Newtonian Hydrodynamics with Arbitrary Volumetric Sources
Lowrie, Robert Byron
2015-11-12
In this note, we derive how to handle mass, momentum, and energy sources for Newtonian hydrodynamics. Much of this is classic, although we’re unaware of a reference that treats mass sources, necessary for certain physics and the method of manufactured solutions. In addition, we felt it important to emphasize that the integral form of the governing equations results in a straightforward treatment of the sources. With the integral form, we’ll demonstrate that there’s no ambiguity between the Lagrangian and Eulerian form of the equations, which is less clear with the differential forms.
Application of Perona Malik anisotropic diffusion on digital radiographic image
Halim, Suhaila Abd; Razak, Rohayu Abdul; Ibrahim, Arsmah; Manurung, Yupiter HP
2014-07-10
Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.
Effects on the Physical Environment (Hydrodynamics, and Water Quality Food
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Web) | Department of Energy and Water Quality Food Web) Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web) Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web) 57_mhk_modeling.ppt (7.28 MB) More Documents & Publications Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water Quality) Free Flow Energy (TRL 1 2 3 Component) - Design and Development of a Cross-Platform Submersible Generator Optimized for the
Los Alamos conducts important hydrodynamic experiment in Nevada
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LANL conducts hydrodynamic experiment in Nevada Los Alamos conducts important hydrodynamic experiment in Nevada Hydrodynamic experiments such as Leda involve non-nuclear surrogate materials that mimic many of the properties of nuclear materials. September 8, 2014 Technicians at the Nevada National Security Site make final adjustments to the "Leda" experimental vessel in the "Zero Room" at the underground U1a facility. Technicians at the Nevada National Security Site make
Consistent description of kinetics and hydrodynamics of dusty plasma
Markiv, B.; Tokarchuk, M.; National University Lviv Polytechnic, 12 Bandera St., 79013 Lviv
2014-02-15
A consistent statistical description of kinetics and hydrodynamics of dusty plasma is proposed based on the Zubarev nonequilibrium statistical operator method. For the case of partial dynamics, the nonequilibrium statistical operator and the generalized transport equations for a consistent description of kinetics of dust particles and hydrodynamics of electrons, ions, and neutral atoms are obtained. In the approximation of weakly nonequilibrium process, a spectrum of collective excitations of dusty plasma is investigated in the hydrodynamic limit.
Simulation of Explosion Ground Motions Using a Hydrodynamic-to...
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Simulation of Explosion Ground Motions Using a Hydrodynamic-to-Elastic Coupling Approach in Three-Dimensions Citation Details In-Document Search Title: Simulation of Explosion ...
Hydrodynamic and Membrane Binding Properties of Purified Rous...
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Purified Rous Sarcoma Virus Gag Protein Citation Details In-Document Search Title: Hydrodynamic and Membrane Binding Properties of Purified Rous Sarcoma Virus Gag Protein ...
Hydrodynamic Focusing Micropump Module with PDMS/Nickel Particle
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(MFSM) micropump module combined with Tesla valves and hydrodynamic focusing ... Each micropump consists of Tesla-type valves in the bottom layer and PDMSNi-particle ...
Collisional-Radiative Modeling for Radiation Hydrodynamics (Book...
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Publisher: Modern Methods in Collisional-Radiative Modelling of Plasmas, Collisional-Radiative Modeling for Radiation Hydrodynamics, Springer International Publishing, unknown, ...
Hydrodynamic interactions in metal rod-like particle suspensions...
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We present a theoretical and experimental study of the role of hydrodynamic interactions ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 42 ...
Violation of the Wiedemann-Franz Law in Hydrodynamic Electron...
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Violation of the Wiedemann-Franz Law in Hydrodynamic Electron Liquids This content will become publicly available on July 30, 2016 Prev Next Title: Violation of the ...
Violation of the Wiedemann-Franz Law in Hydrodynamic Electron...
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Journal Article: Violation of the Wiedemann-Franz Law in Hydrodynamic Electron Liquids Citation Details In-Document Search This content will become publicly available on July 30, ...
MHK Projects/Marine Hydrodynamics Laboratory at the University...
Marine Hydrodynamics Laboratory at the University of Michigan < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"map...
Effect of Second-Order Hydrodynamics on Floating Offshore Wind Turbines: Preprint
Roald, L.; Jonkman, J.; Robertson, A,; Chokani, N.
2013-07-01
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.
NNSA's Summary of Experiments Conducted in Support of Stockpile...
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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 ...
NNSA's Stockpile Stewardship Program Quarterly Experiments summary...
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These include some of the most sophisticated scientific research facilities in the world including, the Dual Axis Radiographic Hydrodynamic Test facility at Los Alamos National ...
Los Alamos National Laboratory to begin DARHT 2 operations
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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...
OC5 Project Phase I: Validation of Hydrodynamic Loading on a Fixed Cylinder: Preprint
Robertson, A. N.; Wendt, F. F.; Jonkman, J. M.; Popko, W.; Vorpahl, F.; Stansberg, C. T.; Bachynski, E. E.; Bayati, I.; Beyer, F.; de Vaal, J. B.; Harries, R.; Yamaguchi, A.; Shin, H.; Kim, B.; van der Zee, T.; Bozonnet, P.; Aguilo, B.; Bergua, R.; Qvist, J.; Qijun, W.; Chen, X.; Guerinel, M.; Tu, Y.; Yutong, H.; Li, R.; Bouy, L.
2015-04-23
This paper describes work performed during the first half of Phase I of the Offshore Code Comparison Collaboration Continuation, with Correlation project (OC5). OC5 is a project run under the IEA Wind Research Task 30, and is focused on validating the tools used for modeling offshore wind systems. In this first phase, simulated responses from a variety of offshore wind modeling tools were modeling tools were validated against tank test data of a fixed, suspended cylinder (without a wind turbine) that was tested under regular and irregular wave conditions at MARINTEK. The results from this phase include an examination of different approaches one can use for defining and calibrating hydrodynamic coefficients for a model, and the importance of higher-order wave models in accurately modeling the hydrodynamic loads on offshore substructures.
Explicit 2-D Hydrodynamic FEM Program
1996-08-07
DYNA2D* is a vectorized, explicit, two-dimensional, axisymmetric and plane strain finite element program for analyzing the large deformation dynamic and hydrodynamic response of inelastic solids. DYNA2D* contains 13 material models and 9 equations of state (EOS) to cover a wide range of material behavior. The material models implemented in all machine versions are: elastic, orthotropic elastic, kinematic/isotropic elastic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, rubber, high explosive burn, isotropic elastic-plastic, temperature-dependent elastic-plastic. The isotropic and temperature-dependent elastic-plastic models determine only the deviatoric stresses. Pressure is determined by one of 9 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, and tabulated.
Explicit 2-D Hydrodynamic FEM Program
Energy Science and Technology Software Center (OSTI)
1996-08-07
DYNA2D* is a vectorized, explicit, two-dimensional, axisymmetric and plane strain finite element program for analyzing the large deformation dynamic and hydrodynamic response of inelastic solids. DYNA2D* contains 13 material models and 9 equations of state (EOS) to cover a wide range of material behavior. The material models implemented in all machine versions are: elastic, orthotropic elastic, kinematic/isotropic elastic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, rubber, high explosive burn, isotropic elastic-plastic, temperature-dependent elastic-plastic. Themore » isotropic and temperature-dependent elastic-plastic models determine only the deviatoric stresses. Pressure is determined by one of 9 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, and tabulated.« less
Outpatient radiographic exposure in the first five years of life
Fosarelli, P.D.; DeAngelis, C.
1987-06-01
Young children receive a variety of diagnostic radiographs over time. In some cases the exposure to radiation may be unwarranted because the films may yield confusing results, or may also need to be repeated because of poor technical quality. Even when the results are clearly negative, the subsequent treatment may proceed as if the film had been positive because of the child's clinical condition. The cumulative effect of such low-dose radiation on infants and children over time is unknown. The number and types of outpatient radiographs received by a cohort of poor children from a hospital-based continuity clinic during their first 5 years of life were reviewed. Also noted were the reason for obtaining the film, whether it was positive for that reason or another, whether the child had a chronic condition that prompted the use of radiograph, and the child's sex, race, and age when the film was obtained. Of the 218 children, 132 (60.6%) received 349 sets of films in their first 5 years. There was no difference in the number of films by race or sex. Chest and posttrauma bone or joint films accounted for 315 sets of films or 90.3% of the total. Overall, 25.8% of the 267 chest films were positive; this varied by age. Only 15% of the chest films were positive in the first year compared with 29 to 49% in the second through fifth years (p less than 0.001). Cough was the respiratory symptom most reliably associated with a positive chest film, both for the cohort (p less than 0.0001) and for children in the first year of life (p less than 0.01).
A DENSITY-INDEPENDENT FORMULATION OF SMOOTHED PARTICLE HYDRODYNAMICS
Saitoh, Takayuki R.; Makino, Junichiro
2013-05-01
The standard formulation of the smoothed particle hydrodynamics (SPH) assumes that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives of other quantities. However, this assumption breaks down at the contact discontinuity. At the contact discontinuity, the density of the low-density side is overestimated while that of the high-density side is underestimated. As a result, the pressure of the low-density (high-density) side is overestimated (underestimated). Thus, unphysical repulsive force appears at the contact discontinuity, resulting in the effective surface tension. This tension suppresses fluid instabilities. In this paper, we present a new formulation of SPH, which does not require the differentiability of density. Instead of the mass density, we adopt the internal energy density (pressure) and its arbitrary function, which are smoothed quantities at the contact discontinuity, as the volume element used for the kernel integration. We call this new formulation density-independent SPH (DISPH). It handles the contact discontinuity without numerical problems. The results of standard tests such as the shock tube, Kelvin-Helmholtz and Rayleigh-Taylor instabilities, point-like explosion, and blob tests are all very favorable to DISPH. We conclude that DISPH solved most of the known difficulties of the standard SPH, without introducing additional numerical diffusion or breaking the exact force symmetry or energy conservation. Our new SPH includes the formulation proposed by Ritchie and Thomas as a special case. Our formulation can be extended to handle a non-ideal gas easily.
IUTAM symposium on hydrodynamic diffusion of suspended particles
Davis, R.H.
1995-12-31
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.
Zingale, M; Howell, L H
2010-03-17
The motivation for this work is to gain experience in the methodology of verification and validation (V&V) of astrophysical radiation hydrodynamics codes. In the first period of this work, we focused on building the infrastructure to test a single astrophysical application code, Castro, developed in collaboration between Lawrence Livermore National Laboratory (LLNL) and Lawrence Berkeley Laboratory (LBL). We delivered several hydrodynamic test problems, in the form of coded initial conditions and documentation for verification, routines to perform data analysis, and a generalized regression test suite to allow for continued automated testing. Astrophysical simulation codes aim to model phenomena that elude direct experimentation. Our only direct information about these systems comes from what we observe, and may be transient. Simulation can help further our understanding by allowing virtual experimentation of these systems. However, to have confidence in our simulations requires us to have confidence in the tools we use. Verification and Validation is a process by which we work to build confidence that a simulation code is accurately representing reality. V&V is a multistep process, and is never really complete. Once a single test problem is working as desired (i.e. that problem is verified), one wants to ensure that subsequent code changes do not break that test. At the same time, one must also search for new verification problems that test the code in a new way. It can be rather tedious to manually retest each of the problems, so before going too far with V&V, it is desirable to have an automated test suite. Our project aims to provide these basic tools for astrophysical radiation hydrodynamics codes.
Patient-based radiographic exposure factor selection: a systematic review
Ching, William; Robinson, John; McEntee, Mark
2014-09-15
Digital technology has wider exposure latitude and post-processing algorithms which can mask the evidence of underexposure and overexposure. Underexposure produces noisy, grainy images which can impede diagnosis and overexposure results in a greater radiation dose to the patient. These exposure errors can result from inaccurate adjustment of exposure factors in response to changes in patient thickness. This study aims to identify all published radiographic exposure adaptation systems which have been, or are being, used in general radiography and discuss their applicability to digital systems. Studies in EMBASE, MEDLINE, CINAHL and SCOPUS were systematically reviewed. Some of the search terms used were exposure adaptation, exposure selection, exposure technique, 25% rule, 15% rule, DuPont™ Bit System and radiography. A manual journal-specific search was also conducted in The Radiographer and Radiologic Technology. Studies were included if they demonstrated a system of altering exposure factors to compensate for variations in patients for general radiography. Studies were excluded if they focused on finding optimal exposures for an ‘average’ patient or focused on the relationship between exposure factors and dose. The database search uncovered 11 articles and the journal-specific search uncovered 13 articles discussing systems of exposure adaptation. They can be categorised as simple one-step guidelines, comprehensive charts and computer programs. Only two papers assessed the efficacy of exposure adjustment systems. No literature compares the efficacy of exposure adaptations system for film/screen radiography with digital radiography technology nor is there literature on a digital specific exposure adaptation system.
Metrics for Developing an Endorsed Set of Radiographic Threat Surrogates for JINII/CAARS
Wurtz, R; Walston, S; Dietrich, D; Martz, H
2009-02-11
CAARS (Cargo Advanced Automated Radiography System) is developing x-ray dual energy and x-ray backscatter methods to automatically detect materials that are greater than Z=72 (hafnium). This works well for simple geometry materials, where most of the radiographic path is through one material. However, this is usually not the case. Instead, the radiographic path includes many materials of different lengths. Single energy can be used to compute {mu}y{sub l} which is related to areal density (mass per unit area) while dual energy yields more information. This report describes a set of metrics suitable and sufficient for characterizing the appearance of assemblies as detected by x-ray radiographic imaging systems, such as those being tested by Joint Integrated Non-Intrusive Inspection (JINII) or developed under CAARS. These metrics will be simulated both for threat assemblies and surrogate threat assemblies (such as are found in Roney et al. 2007) using geometrical and compositional information of the assemblies. The imaging systems are intended to distinguish assemblies containing high-Z material from those containing low-Z material, regardless of thickness, density, or compounds and mixtures. The systems in question operate on the principle of comparing images obtained by using two different x-ray end-point energies--so-called 'dual energy' imaging systems. At the direction of the DHS JINII sponsor, this report does not cover metrics that implement scattering, in the form of either forward-scattered radiation or high-Z detection systems operating on the principle of backscatter detection. Such methods and effects will be covered in a later report. The metrics described here are to be used to compare assemblies and not x-ray radiography systems. We intend to use these metrics to determine whether two assemblies do or do not look the same. We are tasked to develop a set of assemblies whose appearance using this class of detection systems is indistinguishable from the
Triangular flow in hydrodynamics and transport theory
Alver, Burak Han [Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Gombeaud, Clement; Luzum, Matthew; Ollitrault, Jean-Yves [CNRS, URA2306, IPhT, Institut de physique theorique de Saclay, F-91191 Gif-sur-Yvette (France)
2010-09-15
In ultrarelativistic heavy-ion collisions, the Fourier decomposition of the relative azimuthal angle, {Delta}{phi}, distribution of particle pairs yields a large cos(3{Delta}{phi}) component, extending to large rapidity separations {Delta}{eta}>1. This component captures a significant portion of the ridge and shoulder structures in the {Delta}{phi} distribution, which have been observed after contributions from elliptic flow are subtracted. An average finite triangularity owing to event-by-event fluctuations in the initial matter distribution, followed by collective flow, naturally produces a cos(3{Delta}{phi}) correlation. Using ideal and viscous hydrodynamics and transport theory, we study the physics of triangular (v{sub 3}) flow in comparison to elliptic (v{sub 2}), quadrangular (v{sub 4}), and pentagonal (v{sub 5}) flow. We make quantitative predictions for v{sub 3} at RHIC and LHC as a function of centrality and transverse momentum. Our results for the centrality dependence of v{sub 3} show a quantitative agreement with data extracted from previous correlation measurements by the STAR collaboration. This study supports previous results on the importance of triangular flow in the understanding of ridge and shoulder structures. Triangular flow is found to be a sensitive probe of initial geometry fluctuations and viscosity.
Viscosity and Vorticity in Reduced Magneto-Hydrodynamics
Joseph, Ilon
2015-08-12
Magneto-hydrodynamics (MHD) critically relies on viscous forces in order for an accurate determination of the electric eld. For each charged particle species, the Braginskii viscous tensor for a magnetized plasma has the decomposition into matrices with special symmetries.
Hydrodynamic interactions in metal rod-like particle suspensions...
Office of Scientific and Technical Information (OSTI)
and experimental study of the role of hydrodynamic interactions on the motion and dispersion of metal rod-like particles in the presence of an externally applied electric field. ...
Simulating Magnetized Laboratory Plasmas with Smoothed Particle Hydrodynamics
Johnson, J N
2009-07-02
The creation of plasmas in the laboratory continues to generate excitement in the physics community. Despite the best efforts of the intrepid plasma diagnostics community, the dynamics of these plasmas remains a difficult challenge to both the theorist and the experimentalist. This dissertation describes the simulation of strongly magnetized laboratory plasmas with Smoothed Particle Hydrodynamics (SPH), a method born of astrophysics but gaining broad support in the engineering community. We describe the mathematical formulation that best characterizes a strongly magnetized plasma under our circumstances of interest, and we review the SPH method and its application to astrophysical plasmas based on research by Phillips [1], Buerve [2], and Price and Monaghan [3]. Some modifications and extensions to this method are necessary to simulate terrestrial plasmas, such as a treatment of magnetic diffusion based on work by Brookshaw [4] and by Atluri [5]; we describe these changes as we turn our attention toward laboratory experiments. Test problems that verify the method are provided throughout the discussion. Finally, we apply our method to the compression of a magnetized plasma performed by the Compact Toroid Injection eXperiment (CTIX) [6] and show that the experimental results support our computed predictions.
A Godunov-like point-centered essentially Lagrangian hydrodynamic approach
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.
2014-10-28
discretization. A 2-stage RungeKutta method is used to evolve the solution in time. The details of the new hydrodynamic scheme are discussed; likewise, results from numerical test problems are presented.
A Godunov-like point-centered essentially Lagrangian hydrodynamic approach
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.
2014-10-28
discretization. A 2-stage Runge–Kutta method is used to evolve the solution in time. The details of the new hydrodynamic scheme are discussed; likewise, results from numerical test problems are presented.« less
Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and
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Water Quality) | Department of Energy Sediment Transport, and Water Quality) Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water Quality) Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water Quality) 56_tools_methods_to_measure_predict_envrionmental_impacts_snl_roberts.pptx (2.23 MB) More Documents & Publications FY 09 Lab Call: Research & Assessment for MHK Development 2014 Water Power Program Peer Review Compiled
A point-centered arbitrary Lagrangian Eulerian hydrodynamic approach for tetrahedral meshes
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.
2015-02-24
We present a three dimensional (3D) arbitrary Lagrangian Eulerian (ALE) hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedral meshes. The new approach stores the conserved variables (mass, momentum, and total energy) at the nodes of the mesh and solves the conservation equations on a control volume surrounding the point. This type of an approach is termed a point-centered hydrodynamic (PCH) method. The conservation equations are discretized using an edge-based finite element (FE) approach with linear basis functions. All fluxes in the new approach are calculated at the center of each tetrahedron. A multidirectional Riemann-like problem is solved atmore » the center of the tetrahedron. The advective fluxes are calculated by solving a 1D Riemann problem on each face of the nodal control volume. A 2-stage Runge–Kutta method is used to evolve the solution forward in time, where the advective fluxes are part of the temporal integration. The mesh velocity is smoothed by solving a Laplacian equation. The details of the new ALE hydrodynamic scheme are discussed. Results from a range of numerical test problems are presented.« less
A point-centered arbitrary Lagrangian Eulerian hydrodynamic approach for tetrahedral meshes
Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.
2015-02-24
We present a three dimensional (3D) arbitrary Lagrangian Eulerian (ALE) hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedral meshes. The new approach stores the conserved variables (mass, momentum, and total energy) at the nodes of the mesh and solves the conservation equations on a control volume surrounding the point. This type of an approach is termed a point-centered hydrodynamic (PCH) method. The conservation equations are discretized using an edge-based finite element (FE) approach with linear basis functions. All fluxes in the new approach are calculated at the center of each tetrahedron. A multidirectional Riemann-like problem is solved at the center of the tetrahedron. The advective fluxes are calculated by solving a 1D Riemann problem on each face of the nodal control volume. A 2-stage RungeKutta method is used to evolve the solution forward in time, where the advective fluxes are part of the temporal integration. The mesh velocity is smoothed by solving a Laplacian equation. The details of the new ALE hydrodynamic scheme are discussed. Results from a range of numerical test problems are presented.
Developing radiographer roles in the context of advanced and consultant practice
Field, Lisa J; Snaith, Beverly A
2013-03-15
Skill-mix initiatives have provided opportunities for radiographers to develop roles and achieve their potential, thus contributing to radiographer retention rates and increased job satisfaction. This reflective article explores two radiographic roles within an interprofessional context including the implications for confidence, competence, and future sustainability. These were reporting roles which extended into two modalities, one into bone densitometry and another into ultrasound. This article discusses how successful skill mix can benefit the individual, their department, and NHS organization and that role expansion can develop a more dynamic and resourceful workforce with transferability of skills and attributes.
Neuroimaging in adult penetrating brain injury: a guide for radiographers
Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren
2015-06-15
Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.
Magneto-hydrodynamic detection of vortex shedding for molten salt flow sensing.
Kruizenga, Alan Michael; Crocker, Robert W.
2012-09-01
High temperature flow sensors must be developed for use with molten salts systems at temperatures in excess of 600%C2%B0C. A novel magneto-hydrodynamic sensing approach was investigated. A prototype sensor was developed and tested in an aqueous sodium chloride solution as a surrogate for molten salt. Despite that the electrical conductivity was a factor of three less than molten salts, it was found that the electrical conductivity of an electrolyte was too low to adequately resolve the signal amidst surrounding noise. This sensor concept is expected to work well with any liquid metal application, as the generated magnetic field scales proportionately with electrical conductivity.
Hydrodynamic evolution and jet energy loss in Cu + Cu collisions
Schenke, Bjoern; Jeon, Sangyong; Gale, Charles
2011-04-15
We present results from a hybrid description of Cu + Cu collisions using (3 + 1)-dimensional hydrodynamics (music) for the bulk evolution and a Monte Carlo simulation (martini) for the evolution of high-momentum partons in the hydrodynamical background. We explore the limits of this description by going to small system sizes and determine the dependence on different fractions of wounded nucleon and binary collisions scaling of the initial energy density. We find that Cu + Cu collisions are well described by the hybrid description at least up to 20% central collisions.
3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK
Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D
2006-08-24
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.
Application of a panel method to hydrodynamics of underwater vehicles
Sahin, I.; Crane, J.W.; Watson, K.P.
1994-12-31
A low-order singularity panel method based on Green`s formulation is used to predict the hydrodynamics characteristics of underwater vehicles. The low-order modeling employs constant strength sources and doublets, and the body surface is modeled by quadrilaterals. The method is first applied to predicting the force and moment coefficients of underwater vehicles for the body-alone and finned configurations. Hydrodynamic coefficients of added mass and added moment of inertia are also calculated by modifying the code. Results for several two and three-dimensional bodies show the usefulness of the method for predicting the added mass and added moment of inertia.
(3+1)D hydrodynamic simulation of relativistic heavy-ion collisions...
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(3+1)D hydrodynamic simulation of relativistic heavy-ion collisions Citation Details In-Document Search Title: (3+1)D hydrodynamic simulation of relativistic heavy-ion collisions ...
Event-by-event hydrodynamics: A better tool to study the Quark-Gluon plasma
Grassi, Frederique
2013-03-25
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.
On the explanation and calculation of anomalous reflood hydrodynamics in large PWR cores
Rodriguez, S.E.
1985-01-01
Reflood hydrodynamics from large-scale (1:20) test facilities in Japan have yielded apparently anomalous behavior relative to FLECHT tests. Namely, even at reflooding rates below one inch per second, very large liquid volume fractions (10-15%) exist above the quench fronts shortly after flood begins; thus cladding temperature excursions are terminated early in the reflood phase. This paper discusses an explanation for this behavior: liquid films on the core's unheated rods. The experimental findings are shown to be correctly simulated with a new four-field (vapor, films, droplets) version of the best-estimate TRAC-PF1 computer code, TRAC-FF. These experimental and analytical findings have important implications for PWR large-break LOCA licensing.
Validating hydrodynamic growth in National Ignition Facility implosions
Peterson, J. L. Casey, D. T.; Hurricane, O. A.; Raman, K. S.; Robey, H. F.; Smalyuk, V. A.
2015-05-15
We present new hydrodynamic growth experiments at the National Ignition Facility, which extend previous measurements up to Legendre mode 160 and convergence ratio 4, continuing the growth factor dispersion curve comparison of the low foot and high foot pulses reported by Casey et al. [Phys. Rev. E 90, 011102(R) (2014)]. We show that the high foot pulse has lower growth factor and lower growth rate than the low foot pulse. Using novel on-capsule fiducial markers, we observe that mode 160 inverts sign (changes phase) for the high foot pulse, evidence of amplitude oscillations during the Richtmyer-Meshkov phase of a spherically convergent system. Post-shot simulations are consistent with the experimental measurements for all but the shortest wavelength perturbations, reinforcing the validity of radiation hydrodynamic simulations of ablation front growth in inertial confinement fusion capsules.
Low torque hydrodynamic lip geometry for rotary seals
Dietle, Lannie L.; Schroeder, John E.
2015-07-21
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.
Matching pre-equilibrium dynamics and viscous hydrodynamics
Martinez, Mauricio; Strickland, Michael
2010-02-15
We demonstrate how to match pre-equilibrium dynamics of a 0+1-dimensional quark-gluon plasma to second-order viscous hydrodynamical evolution. The matching allows us to specify the initial values of the energy density and shear tensor at the initial time of hydrodynamical evolution as a function of the lifetime of the pre-equilibrium period. We compare two models for pre-equilibrium quark-gluon plasma, longitudinal free streaming and collisionally broadened longitudinal expansion, and present analytic formulas that can be used to fix the necessary components of the energy-momentum tensor. The resulting dynamical models can be used to assess the effect of pre-equilibrium dynamics on quark-gluon plasma observables. Additionally, we investigate the dependence of entropy production on pre-equilibrium dynamics and discuss the limitations of the standard definitions of nonequilibrium entropy.
Performance evaluation of half-wetted hydrodynamic bearings with DLC coated surfaces.
Eryilmaz, O.; Erdemir, A.; Energy Systems
2008-01-01
In conventional liquid lubrication it is assumed that surfaces are fully wetted and no slip occurs between the fluid and the solid boundary. Under the 'no slip' condition the maximum shear gradient occurs at the fluid-surface interface. When one or both surfaces are non-wetted by the fluid, boundary slip can occur due to weak bonding between the fluid and the solid surface, which reduces shear stresses in the fluid adjacent to the non-wetted surface. A thrust bearing tribometer was used to compare the performance of 'no slip' hydrodynamic thrust bearings with bearings surfaces that were made to slip at the interface between the surface and fluid. Hydrophobic surfaces on both runner and bearing were achieved with the deposition of hydrogenated diamond like carbon (H-DLC) films, produced by plasma-enhanced CVD on titanium alloy surfaces. Hydrophilic surfaces were created through the surface modification of DLC. A mixtures of water and glycerol was used as the lubricant. The tests were conducted using different constant bearing gaps. The normal load and the torque or traction force between the rotating runner and hydrodynamic thrust bearing were measured with load cells. The experimental results confirmed that load support is still possible when surfaces are partially-wetted or nonwetted.
THE KOZAI-LIDOV MECHANISM IN HYDRODYNAMICAL DISKS
Martin, Rebecca G.; Nixon, Chris; Armitage, Philip J. [JILA, University of Colorado and NIST, UCB 440, Boulder, CO 80309 (United States); Lubow, Stephen H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Price, Daniel J. [Monash Centre for Astrophysics (MoCA), School of Mathematical Sciences, Monash University, Clayton, Vic. 3800 (Australia); Do?an, Suzan [Department of Astronomy and Space Sciences, University of Ege, Bornova, 35100 ?zmir (Turkey); King, Andrew [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)
2014-09-10
We use three-dimensional hydrodynamical simulations to show that a highly misaligned accretion disk around one component of a binary system can exhibit global Kozai-Lidov cycles, where the inclination and eccentricity of the disk are interchanged periodically. This has important implications for accreting systems on all scales, for example, the formation of planets and satellites in circumstellar and circumplanetary disks, outbursts in X-ray binary systems, and accretion onto supermassive black holes.
Analytical Solutions of Landau (1+1)-Dimensional Hydrodynamics
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sen, Abhisek; Gerhard, Jochen; Torrieri, Giorgio; Read, Jr, Kenneth F
2014-01-01
To help guide our intuition, summarize important features, and point out essential elements, we review the analytical solutions of Landau (1+1)-dimensional hydrodynamics and exhibit the full evolution of the dynamics from the very beginning to subsequent times. Special emphasis is placed on the matching and the interplay between the Khalatnikov solution and the Riemann simple wave solution at the earliest times and in the edge regions at later times.
Skew and twist resistant hydrodynamic rotary shaft seal
Dietle, Lannie; Kalsi, Manmohan Singh
1999-01-01
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.
Skew and twist resistant hydrodynamic rotary shaft seal
Dietle, L.; Kalsi, M.S.
1999-02-23
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.
Real-time spot size camera for pulsed high-energy radiographic machines
Watson, S.A.
1993-06-01
The focal spot size of an x-ray source is a critical parameter which degrades resolution in a flash radiograph. For best results, a small round focal spot is required. Therefore, a fast and accurate measurement of the spot size is highly desirable to facilitate machine tuning. This paper describes two systems developed for Los Alamos National Laboratory`s Pulsed High-Energy Radiographic Machine Emitting X-rays (PHERMEX) facility. The first uses a CCD camera combined with high-brightness floors, while the second utilizes phosphor storage screens. Other techniques typically record only the line spread function on radiographic film, while systems in this paper measure the more general two-dimensional point-spread function and associated modulation transfer function in real time for shot-to-shot comparison.
Real-time spot size camera for pulsed high-energy radiographic machines
Watson, S.A.
1993-01-01
The focal spot size of an x-ray source is a critical parameter which degrades resolution in a flash radiograph. For best results, a small round focal spot is required. Therefore, a fast and accurate measurement of the spot size is highly desirable to facilitate machine tuning. This paper describes two systems developed for Los Alamos National Laboratory's Pulsed High-Energy Radiographic Machine Emitting X-rays (PHERMEX) facility. The first uses a CCD camera combined with high-brightness floors, while the second utilizes phosphor storage screens. Other techniques typically record only the line spread function on radiographic film, while systems in this paper measure the more general two-dimensional point-spread function and associated modulation transfer function in real time for shot-to-shot comparison.
DYNA3D. Explicit 3-d Hydrodynamic FEM Program
Chu, R.; Amakai, M.; Lung, H.C.; Ishigai, T.
1989-05-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D. Explicit 3-d Hydrodynamic FEM Program
Kennedy, T.
1989-05-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, and resultant plasticity. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack `Tuesday` high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
Hydrodynamically Lubricated Rotary Shaft Having Twist Resistant Geometry
Dietle, Lannie; Gobeli, Jeffrey D.
1993-07-27
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.
Correlating hydrodynamic radii with that of two-dimensional nanoparticles
Yue, Yuan; Kan, Yuwei; Clearfield, Abraham; Choi, Hyunho; Liang, Hong
2015-12-21
Dynamic light scattering (DLS) is one of the most adapted methods to measure the size of nanoparticles, as referred to the hydrodynamic radii (R{sub h}). However, the R{sub h} represents only that of three-dimensional spherical nanoparticles. In the present research, the size of two-dimensional (2D) nanoparticles of yttrium oxide (Y{sub 2}O{sub 3}) and zirconium phosphate (ZrP) was evaluated through comparing their hydrodynamic diameters via DLS with lateral sizes obtained using scanning and transmission electron microscopy. We demonstrate that the hydrodynamic radii are correlated with the lateral sizes of both square and circle shaped 2D nanoparticles. Two proportional coefficients, i.e., correcting factors, are proposed for the Brownian motion status of 2D nanoparticles. The correction is possible by simplifying the calculation of integrals in the case of small thickness approximation. The correcting factor has great significance for investigating the translational diffusion behavior of 2D nanoparticles in a liquid and in effective and low-cost measurement in terms of size and morphology of shape-specific nanoparticles.
Haefner, L C; Heebner, J E; Dawson, J W; Fochs, S N; Shverdin, M Y; Crane, J K; Kanz, K V; Halpin, J M; Phan, H H; Sigurdsson, R J; Brewer, S W; Britten, J A; Brunton, G K; Clark, W J; Messerly, M J; Nissen, J D; Shaw, B H; Hackel, R P; Hermann, M R; Tietbohl, G L; Siders, C W; Barty, C J
2009-10-23
We have characterized the Advanced Radiographic Capability injection laser system and demonstrated that it meets performance requirements for upcoming National Ignition Facility fusion experiments. Pulse compression was achieved with a scaled down replica of the meter-scale grating ARC compressor and sub-ps pulse duration was demonstrated at the Joule-level.
Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors
Sale, D.; Jonkman, J.; Musial, W.
2009-08-01
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.
Mixed-RKDG Finite Element Methods for the 2-D Hydrodynamic Model for Semiconductor Device Simulation
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chen, Zhangxin; Cockburn, Bernardo; Jerome, Joseph W.; Shu, Chi-Wang
1995-01-01
In this paper we introduce a new method for numerically solving the equations of the hydrodynamic model for semiconductor devices in two space dimensions. The method combines a standard mixed finite element method, used to obtain directly an approximation to the electric field, with the so-called Runge-Kutta Discontinuous Galerkin (RKDG) method, originally devised for numerically solving multi-dimensional hyperbolic systems of conservation laws, which is applied here to the convective part of the equations. Numerical simulations showing the performance of the new method are displayed, and the results compared with those obtained by using Essentially Nonoscillatory (ENO) finite difference schemes. Frommore » the perspective of device modeling, these methods are robust, since they are capable of encompassing broad parameter ranges, including those for which shock formation is possible. The simulations presented here are for Gallium Arsenide at room temperature, but we have tested them much more generally with considerable success.« less
Connectivity structures and differencing techniques for staggered-grid free-Lagrange hydrodynamics
Burton, D.E.
1992-06-01
We consider a variation of the free-Lagrange (FL) method which is appropriate to staggered-grid differencing of the hydrodynamics equations (SGH) and will be termed the staggered free-Lagrange method or SFL. The SFL method discretizes space into general polygonal or polyhedral cells. The numerical differencing techniques and connectivity templates used for SFL differ markedly from those used by other unstructured grid methods, such as finite element (FE) and triangular/tetrahedral based free-Lagrange (TFL). The paper discusses the spatial discretization for both 2D and 3D geometry, differencing templates, object-oriented data management, and mesh optimization and refinement strategies. The suite of mesh optimization primitives is extended, giving rise to a powerful hybrid method called adaptive free-Lagrange (AFL) which is applied to a test problem.
DYNA3D. Explicit 3-D Hydrodynamic FEM Program
Whirley, R.G.; Englemann, B.E.
1993-11-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack `Tuesday` high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D. Explicit 3-d Hydrodynamic FEM Program
Whirley, R.G.; Englemann, B.E.
1993-11-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D. Explicit 3-D Hydrodynamic FEM Program
Whirley, R.G.
1989-05-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack `Tuesday` high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D; Explicit 3-d Hydrodynamic FEM Program
Whirley, R.G.
1989-05-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D. Explicit 3-d Hydrodynamic FEM Program
Whirley, R.G.; Englemann, B.E. )
1993-11-30
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
DYNA3D. Explicit 3-D Hydrodynamic FEM Program
Whirley, R.G.
1989-05-01
DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.
Assessment of Nuclear Fuels using Radiographic Thickness Measurement Method
Muhammad Abir; Fahima Islam; Hyoung Koo Lee; Daniel Wachs
2014-11-01
The Convert branch of the National Nuclear Security Administration (NNSA) Global Threat Reduction Initiative (GTRI) focuses on the development of high uranium density fuels for research and test reactors for nonproliferation. This fuel is aimed to convert low density high enriched uranium (HEU) based fuel to high density low enriched uranium (LEU) based fuel for high performance research reactors (HPRR). There are five U.S. reactors that fall under the HPRR category, including: the Massachusetts Institute of Technology Reactor (MITR), the National Bureau of Standards Reactor (NBSR), the Missouri University Research Reactor (UMRR), the Advanced Test Reactor (ATR), and the High Flux Isotope Reactor (HFIR). U-Mo alloy fuel phase in the form of either monolithic or dispersion foil type fuels, such as ATR Full-size In center flux trap Position (AFIP) and Reduced Enrichment for Research and Test Reactor (RERTR), are being designed for this purpose. The fabrication process1 of RERTR is susceptible to introducing a variety of fuel defects. A dependable quality control method is required during fabrication of RERTR miniplates to maintain the allowable design tolerances, therefore evaluating and analytically verifying the fabricated miniplates for maintaining quality standards as well as safety. The purpose of this work is to analyze the thickness of the fabricated RERTR-12 miniplates using non-destructive technique to meet the fuel plate specification for RERTR fuel to be used in the ATR.
On freeze-out problem in relativistic hydrodynamics
Ivanov, Yu. B., E-mail: Y.Ivanov@gsi.de; Russkikh, V. N. [Gesellschaft fuer Schwerionenforschung mbH (Germany)
2009-07-15
A finite unbound system which is equilibrium in one reference frame is in general nonequilibrium in another frame. This is a consequence of the relative character of the time synchronization in the relativistic physics. This puzzle was a prime motivation of the Cooper-Frye approach to the freeze-out in relativistic hydrodynamics. Solution of the puzzle reveals that the Cooper-Frye recipe is far not a unique phenomenological method that meets requirements of energy-momentum conservation. Alternative freeze-out recipes are considered and discussed.
On the hydrodynamics of salt-gradient solar ponds
Zangrando, F. )
1991-01-01
The objective of this paper is to discuss those hydrodynamical issues that affect the performance of the solar pond as an energy collector and storage system, e.g., mass and energy balance; formation, stability, and maintenance of the gradient layer; energy extraction from the bottom mixed layer; stability of stratified fluids to shearing flows; interface dynamics; and wall effects. Many of these topics are not fully understood and the discussion focuses on the present state of knowledge, some of the engineering correlations available at this time, and the research that is still required to resolve the relevant issues.
Lower bound on the electroweak wall velocity from hydrodynamic instability
Mégevand, Ariel; Membiela, Federico Agustín; Sánchez, Alejandro D.
2015-03-27
The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain critical value. We calculate this critical velocity for several extensions of the Standard Model and compare with an estimation of the wall velocity. In general, we find a region in parameter space which gives stable deflagrations as well as favorable conditions for electroweak baryogenesis.
Skew And Twist Resistant Hydrodynamic Rotary Shaft Seal
Dietle, Lannie; Kalsi, Manmohan Singh
2000-03-14
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.
Numerical simulation of the hydrodynamical combustion to strange quark matter
Niebergal, Brian; Ouyed, Rachid; Jaikumar, Prashanth
2010-12-15
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.
Adding kinetics and hydrodynamics to the CHEETAH thermochemical code
Fried, L.E., Howard, W.M., Souers, P.C.
1997-01-15
In FY96 we released CHEETAH 1.40, which made extensive improvements on the stability and user friendliness of the code. CHEETAH now has over 175 users in government, academia, and industry. Efforts have also been focused on adding new advanced features to CHEETAH 2.0, which is scheduled for release in FY97. We have added a new chemical kinetics capability to CHEETAH. In the past, CHEETAH assumed complete thermodynamic equilibrium and independence of time. The addition of a chemical kinetic framework will allow for modeling of time-dependent phenomena, such as partial combustion and detonation in composite explosives with large reaction zones. We have implemented a Wood-Kirkwood detonation framework in CHEETAH, which allows for the treatment of nonideal detonations and explosive failure. A second major effort in the project this year has been linking CHEETAH to hydrodynamic codes to yield an improved HE product equation of state. We have linked CHEETAH to 1- and 2-D hydrodynamic codes, and have compared the code to experimental data. 15 refs., 13 figs., 1 tab.
Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics
Persson, Rasmus A. X.; Chu, Jhih-Wei, E-mail: jwchu@nctu.edu.tw [Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Voulgarakis, Nikolaos K. [Department of Mathematics, Washington State University, Richland, Washington 99372 (United States)
2014-11-07
Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ? in coupling to the other equations of FHD. The resulting ?-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ?-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ?-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 , the ?-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.
Yang, Zhaoqing; Wang, Taiping
2011-09-01
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.
Method of simulating spherical voids for use as a radiographic standard
Foster, Billy E.
1977-01-01
A method of simulating small spherical voids in metal is provided. The method entails drilling or etching a hemispherical depression of the desired diameter in each of two sections of metal, the sections being flat plates or different diameter cylinders. A carbon bead is placed in one of the hemispherical voids and is used as a guide to align the second hemispherical void with that in the other plate. The plates are then bonded together with epoxy, tape or similar material and the two aligned hemispheres form a sphere within the material; thus a void of a known size has been created. This type of void can be used to simulate a pore in the development of radiographic techniques of actual voids (porosity) in welds and serve as a radiographic standard.
Cross, J. E.; Gregori, G.; Reville, B.
2014-11-01
We introduce the equations of magneto-quantum-radiative hydrodynamics. By rewriting them in a dimensionless form, we obtain a set of parameters that describe scale-dependent ratios of characteristic hydrodynamic quantities. We discuss how these dimensionless parameters relate to the scaling between astrophysical observations and laboratory experiments.
Integral approximations to classical diffusion and smoothed particle hydrodynamics
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Du, Qiang; Lehoucq, R. B.; Tartakovsky, A. M.
2014-12-31
The contribution of the paper is the approximation of a classical diffusion operator by an integral equation with a volume constraint. A particular focus is on classical diffusion problems associated with Neumann boundary conditions. By exploiting this approximation, we can also approximate other quantities such as the flux out of a domain. Our analysis of the model equation on the continuum level is closely related to the recent work on nonlocal diffusion and peridynamic mechanics. In particular, we elucidate the role of a volumetric constraint as an approximation to a classical Neumann boundary condition in the presence of physical boundary.more » The volume-constrained integral equation then provides the basis for accurate and robust discretization methods. As a result, an immediate application is to the understanding and improvement of the Smoothed Particle Hydrodynamics (SPH) method.« less
Symposium on hydrodynamic diffusion of suspended particles. Final report
1996-05-01
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.
Modeling nanoscale hydrodynamics by smoothed dissipative particle dynamics
Lei, Huan; Mundy, Christopher J.; Schenter, Gregory K.; Voulgarakis, Nikolaos
2015-05-21
Thermal fluctuation and hydrophobicity are two hallmarks of fluid hydrodynamics on the nano-scale. It is a challenge to consistently couple the small length and time scale phenomena associated with molecular interaction with larger scale phenomena. The development of this consistency is the essence of mesoscale science. In this study, we develop a nanoscale fluid model based on smoothed dissipative particle dynamics that accounts for the phenomena of associated with density fluctuations and hydrophobicity. We show consistency in the fluctuation spectrum across scales. In doing so, it is necessary to account for finite fluid particle size. Furthermore, we demonstrate that the present model can capture of the void probability and solvation free energy of apolar particles of different sizes. The present fluid model is well suited for a understanding emergent phenomena in nano-scale fluid systems.
Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine
Roald, L.; Jonkman, J.; Robertson, A.
2014-05-01
The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.
National Security, Weapons Science
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Security, Weapons Science National Security, Weapons Science 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. CoMuEx» Explosives Center» Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) The Dual-Axis Radiographic Hydrodynamic Test Facility at Los Alamos National Laboratory is part of the DOE's stockpile stewardship
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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 weapons. The DARHT Facility DARHT consists of two linear induction
Hybrid magneto-hydrodynamic simulation of a driven FRC
Rahman, H. U. Wessel, F. J.; Binderbauer, M. W.; Qerushi, A.; Rostoker, N.; Conti, F.; Plasma Diagnostics and Technologies Ltd., Via Giuntini 63, 56023 Navacchio ; Ney, P.
2014-03-15
We simulate a field-reversed configuration (FRC), produced by an “inductively driven” FRC experiment; comprised of a central-flux coil and exterior-limiter coil. To account for the plasma kinetic behavior, a standard 2-dimensional magneto-hydrodynamic code is modified to preserve the azimuthal, two-fluid behavior. Simulations are run for the FRC's full-time history, sufficient to include: acceleration, formation, current neutralization, compression, and decay. At start-up, a net ion current develops that modifies the applied-magnetic field forming closed-field lines and a region of null-magnetic field (i.e., a FRC). After closed-field lines form, ion-electron drag increases the electron current, canceling a portion of the ion current. The equilibrium is lost as the total current eventually dissipates. The time evolution and magnitudes of the computed current, ion-rotation velocity, and plasma temperature agree with the experiments, as do the rigid-rotor-like, radial-profiles for the density and axial-magnetic field [cf. Conti et al. Phys. Plasmas 21, 022511 (2014)].
Numeric spectral radiation hydrodynamic calculations of supernova shock breakouts
Sapir, Nir; Halbertal, Dorri
2014-12-01
We present here an efficient numerical scheme for solving the non-relativistic one-dimensional radiation-hydrodynamics equations including inelastic Compton scattering, which is not included in most codes and is crucial for solving problems such as shock breakout. The devised code is applied to the problems of a steady-state planar radiation mediated shock (RMS) and RMS breakout from a stellar envelope. The results are in agreement with those of a previous work on shock breakout, in which Compton equilibrium between matter and radiation was assumed and the 'effective photon' approximation was used to describe the radiation spectrum. In particular, we show that the luminosity and its temporal dependence, the peak temperature at breakout, and the universal shape of the spectral fluence derived in this earlier work are all accurate. Although there is a discrepancy between the spectral calculations and the effective photon approximation due to the inaccuracy of the effective photon approximation estimate of the effective photon production rate, which grows with lower densities and higher velocities, the difference in peak temperature reaches only 30% for the most discrepant cases of fast shocks in blue supergiants. The presented model is exemplified by calculations for supernova 1987A, showing the detailed evolution of the burst spectrum. The incompatibility of the stellar envelope shock breakout model results with observed properties of X-ray flashes (XRFs) and the discrepancy between the predicted and observed rates of XRFs remain unexplained.
Density-shear instability in electron magneto-hydrodynamics
Wood, T. S. Hollerbach, R.; Lyutikov, M.
2014-05-15
We discuss a novel instability in inertia-less electron magneto-hydrodynamics (EMHD), which arises from a combination of electron velocity shear and electron density gradients. The unstable modes have a lengthscale longer than the transverse density scale, and a growth-rate of the order of the inverse Hall timescale. We suggest that this density-shear instability may be of importance in magnetic reconnection regions on scales smaller than the ion skin depth, and in neutron star crusts. We demonstrate that the so-called Hall drift instability, previously argued to be relevant in neutron star crusts, is a resistive tearing instability rather than an instability of the Hall term itself. We argue that the density-shear instability is of greater significance in neutron stars than the tearing instability, because it generally has a faster growth-rate and is less sensitive to geometry and boundary conditions. We prove that, for uniform electron density, EMHD is at least as stable as regular, incompressible MHD, in the sense that any field configuration that is stable in MHD is also stable in EMHD. We present a connection between the density-shear instability in EMHD and the magneto-buoyancy instability in anelastic MHD.
Stubbe, E.J.; VanHoenacker, L.; Otero, R.
1994-02-01
This report presents an assessment study for the use of the code RELAP 5/MOD3/5M5 in the calculation of transient hydrodynamic loads on safety and relief discharge pipes. Its predecessor, RELAP 5/MOD1, was found adequate for this kind of calculations by EPRI. The hydrodynamic loads are very important for the discharge piping design because of the fast opening of the valves and the presence of liquid in the upstream loop seals. The code results are compared to experimental load measurements performed at the Combustion Engineering Laboratory in Windsor (US). Those measurements were part of the PWR Valve Test Program undertaken by EPRI after the TMI-2 accident. This particular kind of transients challenges the applicability of the following code models: two-phase choked discharge; interphase drag in conditions with large density gradients; heat transfer to metallic structures in fast changing conditions; two-phase flow at abrupt expansions. The code applicability to this kind of transients is investigated. Some sensitivity analyses to different code and model options are performed. Finally, the suitability of the code and some modeling guidelines are discussed.
Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.
2011-10-01
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.
HEAVY DUST OBSCURATION OF z = 7 GALAXIES IN A COSMOLOGICAL HYDRODYNAMIC SIMULATION
Kimm, Taysun; Cen, Renyue
2013-10-10
Hubble Space Telescope observations with the Wide Field Camera 3/Infrared reveal that galaxies at z ? 7 have very blue ultraviolet (UV) colors, consistent with these systems being dominated by young stellar populations with moderate or little attenuation by dust. We investigate UV and optical properties of the high-z galaxies in the standard cold dark matter model using a high-resolution adaptive mesh refinement cosmological hydrodynamic simulation. For this purpose, we perform panchromatic three-dimensional dust radiative transfer calculations on 198 galaxies of stellar mass 5 10{sup 8}-3 10{sup 10} M{sub ?} with three parameters: the dust-to-metal ratio, the extinction curve, and the fraction of directly escaped light from stars (f{sub esc}). Our stellar mass function is found to be in broad agreement with Gonzalez et al., independent of these parameters. We find that our heavily dust-attenuated galaxies (A{sub V} ? 1.8) can also reasonably match modest UV-optical colors, blue UV slopes, as well as UV luminosity functions, provided that a significant fraction (?10%) of light directly escapes from them. The observed UV slope and scatter are better explained with a Small-Magellanic-Cloud-type extinction curve, whereas a Milky-Way-type curve also predicts blue UV colors due to the 2175 bump. We expect that upcoming observations by the Atacama Large Millimeter/submillimeter Array will be able to test this heavily obscured model.
THE DISTRIBUTION OF SATELLITES AROUND CENTRAL GALAXIES IN A COSMOLOGICAL HYDRODYNAMICAL SIMULATION
Dong, X. C.; Lin, W. P.; Wang, Yang Ocean; Kang, X.; Dutton, Aaron A.; Macci, Andrea V. E-mail: kangxi@pmo.ac.cn
2014-08-20
Observations have shown that the spatial distribution of satellite galaxies is not random, but rather is aligned with the major axes of central galaxies (CGs). The strength of the alignment is dependent on the properties of both the satellites and centrals. Theoretical studies using dissipationless N-body simulations are limited by their inability to directly predict the shape of CGs. Using hydrodynamical simulations including gas cooling, star formation, and feedback, we carry out a study of galaxy alignment and its dependence on the galaxy properties predicted directly from the simulations. We found that the observed alignment signal is well produced, as is the color dependence: red satellites and red centrals both show stronger alignments than their blue counterparts. The reason for the stronger alignment of red satellites is that most of them stay in the inner region of the dark matter halo where the shape of the CG better traces the dark matter distribution. The dependence of alignment on the color of CGs arises from the halo mass dependence, since the alignment between the shape of the central stellar component and the inner halo increases with halo mass. We also find that the alignment of satellites is most strongly dependent on their metallicity, suggesting that the metallicity of satellites, rather than color, is a better tracer of galaxy alignment on small scales. This could be tested in future observational studies.
A Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially
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Dependent Viscosity | Argonne Leadership Computing Facility Smoothed Particle Hydrodynamics-Based Fluid Model With a Spatially Dependent Viscosity Authors: Martys, N.S., George, W.L., Chun, B., Lootens, D. A smoothed particle hydrodynamics approach is utilized to model a non-Newtonian fluid with a spatially varying viscosity. In the limit of constant viscosity, this approach recovers an earlier model for Newtonian fluids of Espa Publication Date: September, 2010 Name of Publication Source:
Microsoft PowerPoint - A new efficient approach for 3D hydrodynamics simulation [Compatibility Mode]
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3039 This document is approved for public release; further dissemination unlimited A new efficient approach for 3D hydrodynamics simulation A new efficient approach for 3D hydrodynamics simulation Current high-fidelity 3D simulation tools are limited by accuracy, performance, and setup time * Tedious problem definition * 2D algorithms often do not scale to 3D * Poor accuracy requires intractable levels of mesh resolution * Legacy tools not easily ported to advanced computer architectures
Muehleman,C.; Li, J.; Zhong, Z.
2006-01-01
Objective: To demonstrate the ability of a novel radiographic technique, Diffraction Enhanced Radiographic Imaging (DEI), to render high contrast images of canine knee joints for identification of cartilage lesions in situ. Methods: DEI was carried out at the X-15A beamline at Brookhaven National Laboratory on intact canine knee joints with varying levels of cartilage damage. Two independent observers graded the DE images for lesions and these grades were correlated to the gross morphological grade. Results: The correlation of gross visual grades with DEI grades for the 18 canine knee joints as determined by observer 1 (r2=0.8856, P=0.001) and observer 2 (r2=0.8818, P=0.001) was high. The overall weighted ? value for inter-observer agreement was 0.93, thus considered high agreement. Conclusion: The present study is the first study for the efficacy of DEI for cartilage lesions in an animal joint, from very early signs through erosion down to subchondral bone, representing the spectrum of cartilage changes occurring in human osteoarthritis (OA). Here we show that DEI allows the visualization of cartilage lesions in intact canine knee joints with good accuracy. Hence, DEI may be applicable for following joint degeneration in animal models of OA.
Using high-intensity laser-generated energetic protons to radiograph directly driven implosions
Zylstra, A. B.; Li, C. K.; Rinderknecht, H. G.; Seguin, F. H.; Petrasso, R. D.; Stoeckl, C.; Meyerhofer, D. D.; Nilson, P.; Sangster, T. C.; Le Pape, S.; Mackinnon, A.; Patel, P.
2012-01-15
The recent development of petawatt-class lasers with kilojoule-picosecond pulses, such as OMEGA EP [L. Waxer et al., Opt. Photonics News 16, 30 (2005)], provides a new diagnostic capability to study inertial-confinement-fusion (ICF) and high-energy-density (HED) plasmas. Specifically, petawatt OMEGA EP pulses have been used to backlight OMEGA implosions with energetic proton beams generated through the target normal sheath acceleration (TNSA) mechanism. This allows time-resolved studies of the mass distribution and electromagnetic field structures in ICF and HED plasmas. This principle has been previously demonstrated using Vulcan to backlight six-beam implosions [A. J. Mackinnon et al., Phys. Rev. Lett. 97, 045001 (2006)]. The TNSA proton backlighter offers better spatial and temporal resolution but poorer spatial uniformity and energy resolution than previous D{sup 3}He fusion-based techniques [C. Li et al., Rev. Sci. Instrum. 77, 10E725 (2006)]. A target and the experimental design technique to mitigate potential problems in using TNSA backlighting to study full-energy implosions is discussed. The first proton radiographs of 60-beam spherical OMEGA implosions using the techniques discussed in this paper are presented. Sample radiographs and suggestions for troubleshooting failed radiography shots using TNSA backlighting are given, and future applications of this technique at OMEGA and the NIF are discussed.
Almeida, G. L.; Silvani, M. I.; Lopes, R. T.
2014-11-11
Two main parameters rule the performance of an Image Acquisition System, namely, spatial resolution and contrast. For radiographic systems using cone beam arrangements, the farther the source, the better the resolution, but the contrast would diminish due to the lower statistics. A closer source would yield a higher contrast but it would no longer reproduce the attenuation map of the object, as the incoming beam flux would be reduced by unequal large divergences and attenuation factors. This work proposes a procedure to correct these effects when the object is comprised of a hull - or encased in it - possessing a shape capable to be described in analytical geometry terms. Such a description allows the construction of a matrix containing the attenuation factors undergone by the beam from the source until its final destination at each coordinate on the 2D detector. Each matrix element incorporates the attenuation suffered by the beam after its travel through the hull wall, as well as its reduction due to the square of distance to the source and the angle it hits the detector surface. When the pixel intensities of the original image are corrected by these factors, the image contrast, reduced by the overall attenuation in the exposure phase, are recovered, allowing one to see details otherwise concealed due to the low contrast. In order to verify the soundness of this approach, synthetic images of objects of different shapes, such as plates and tubes, incorporating defects and statistical fluctuation, have been generated, recorded for further comparison and afterwards processed to improve their contrast. The developed algorithm which, generates processes and plots the images has been written in Fortran 90 language. As the resulting final images exhibit the expected improvements, it therefore seemed worthwhile to carry out further tests with actual experimental radiographies.
Yu, Victoria; Kishan, Amar U.; Cao, Minsong; Low, Daniel; Lee, Percy; Ruan, Dan
2014-03-15
Purpose: To demonstrate a new method of evaluating dose response of treatment-induced lung radiographic injury post-SBRT (stereotactic body radiotherapy) treatment and the discovery of bimodal dose behavior within clinically identified injury volumes. Methods: Follow-up CT scans at 3, 6, and 12 months were acquired from 24 patients treated with SBRT for stage-1 primary lung cancers or oligometastic lesions. Injury regions in these scans were propagated to the planning CT coordinates by performing deformable registration of the follow-ups to the planning CTs. A bimodal behavior was repeatedly observed from the probability distribution for dose values within the deformed injury regions. Based on a mixture-Gaussian assumption, an Expectation-Maximization (EM) algorithm was used to obtain characteristic parameters for such distribution. Geometric analysis was performed to interpret such parameters and infer the critical dose level that is potentially inductive of post-SBRT lung injury. Results: The Gaussian mixture obtained from the EM algorithm closely approximates the empirical dose histogram within the injury volume with good consistency. The average Kullback-Leibler divergence values between the empirical differential dose volume histogram and the EM-obtained Gaussian mixture distribution were calculated to be 0.069, 0.063, and 0.092 for the 3, 6, and 12 month follow-up groups, respectively. The lower Gaussian component was located at approximately 70% prescription dose (35 Gy) for all three follow-up time points. The higher Gaussian component, contributed by the dose received by planning target volume, was located at around 107% of the prescription dose. Geometrical analysis suggests the mean of the lower Gaussian component, located at 35 Gy, as a possible indicator for a critical dose that induces lung injury after SBRT. Conclusions: An innovative and improved method for analyzing the correspondence between lung radiographic injury and SBRT treatment dose has
Silvani, M. I.; Almeida, G. L.; Lopes, R. T.
2014-11-11
Radiographic images acquired with point-like gamma-ray sources exhibit a desirable low penumbra effects specially when positioned far away from the set object-detector. Such an arrangement frequently is not affordable due to the limited flux provided by a distant source. A closer source, however, has two main drawbacks, namely the degradation of the spatial resolution - as actual sources are only approximately punctual - and the non-homogeneity of the beam hitting the detector, which creates a false attenuation map of the object being inspected. This non-homogeneity is caused by the beam divergence itself and by the different thicknesses traversed the beam even if the object were an homogeneous flat plate. In this work, radiographic images of objects with different geometries, such as flat plates and pipes have undergone a correction of beam divergence and attenuation addressing the experimental verification of the capability and soundness of an algorithm formerly developed to generate and process synthetic images. The impact of other parameters, including source-detector gap, attenuation coefficient, ratio defective-to-main hull thickness and counting statistics have been assessed for specifically tailored test-objects aiming at the evaluation of the ability of the proposed method to deal with different boundary conditions. All experiments have been carried out with an X-ray sensitive Imaging Plate and reactor-produced {sup 198}Au and {sup 165}Dy sources. The results have been compared with other technique showing a better capability to correct the attenuation map of inspected objects unveiling their inner structure otherwise concealed by the poor contrast caused by the beam divergence and attenuation, in particular for those regions far apart from the vertical of the source.
Halim, Suhaila Abd; Razak, Rohayu Abd; Ibrahim, Arsmah; Manurung, Yupiter HP
2014-06-19
In image processing, it is important to remove noise without affecting the image structure as well as preserving all the edges. Perona Malik Anisotropic Diffusion (PMAD) is a PDE-based model which is suitable for image denoising and edge detection problems. In this paper, the Peaceman Rachford scheme is applied on PMAD to remove unwanted noise as the scheme is efficient and unconditionally stable. The capability of the scheme to remove noise is evaluated on several digital radiography weld defect images computed using MATLAB R2009a. Experimental results obtained show that the Peaceman Rachford scheme improves the image quality substantially well based on the Peak Signal to Noise Ratio (PSNR). The Peaceman Rachford scheme used in solving the PMAD model successfully removes unwanted noise in digital radiographic image.
Clements, B.E.; Johnson, J.N.
1997-09-01
The nonhomogenized dynamic method of cells (NHDMOC) uses a truncated expansion for the particle displacement field; the expansion parameter is the local cell position vector. In the NHDMOC, specifying the cell structure is similar to specifying the spatial grid used in a finite-difference hydrodynamic calculation. The expansion coefficients for the particle displacement field are determined by the equation of motion, any relevant constitutive relations, plus continuity of traction and displacement at all cell boundaries. The authors derive and numerically solve the NHDMOC equations for the first, second, and third-order expansions, appropriate for modeling a plate-impact experiment. The performance of the NHDMOC is tested, at each order, for its ability to resolve a shock-wave front as it propagates through homogeneous and laminated targets. They find for both cases that the displacement field expansion converges rapidly: given the same cell widths, the first-order theory gives only a qualitative description of the propagating stress wave; the second-order theory performs much better; and the third-order theory gives small refinements over the second-order theory. The performance of the third-order NHDMOC is then compared to that of a standard finite-difference hydrodynamic calculation. The two methods differ in that the former uses a finite-difference solution to update the time dependence of the equations, whereas the hydrodynamic calculation uses finite-difference solutions for both the temporal and spatial variables. Both theories are used to model shock-wave propagation in stainless steel arising from high-velocity planar impact. To achieve the same high-quality resolution of the stress and particle velocity profiles, the NHDMOC consistently requires less fine spatial and temporal grids, and substantially less artificial viscosity to control unphysical high-frequency oscillations in the numerical solutions. Finally, the third-order NHDMOC theory is used to
Hydrodynamics during the Deconfinement Phase Transition from a Hadronic Gas to a Colorless QGP
Ladrem, M.; Zaki-Al-Full, Z.; Herbadji, S.
2011-10-27
The collective flow of hot and dense matter (partonic plasma and hadronic gas) created in an ultra relativistic heavy ion collision can be usually described by hydrodynamics if only the thermalization is achieved and if it can be locally maintained during the subsequent expansion. It requires knowledge of the equation of state, which gives a relation between pressure P, energy density {epsilon}, entropy density s and sound velocityc{sub s}, but no detailed knowledge of the microscopic dynamics. After the study of these hydrodynamical collective observables in a previous work, we investigate in the present work some correlations between them outshining some relevant features of the equation of state and the hydrodynamical expansion of the system undergoing a deconfinement phase transition from hadronic gas to colorless quark gluon plasma. We also investigate the finite volume effect on the collective dynamical evolution of the system.
Jonkman, J. M.; Sclavounos, P. D.
2006-01-01
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.
Recent Hydrodynamics Improvements to the RELAP5-3D Code
Richard A. Riemke; Cliff B. Davis; Richard.R. Schultz
2009-07-01
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.
A flat-cathode thermionic injector for the PHERMEX Radiographic Facility
Kauppila, T.; Builta, L.; Burns, M.; Gregory, W.; Honaberger, D.; Watson, S.; Hughes, T.
1993-06-01
The PHERMEX (Pulsed High-Energy Radiographic Machine Emitting X-rays) standing-wave linear accelerator is a high-current electron beam generator used for flash-radiography. An improved electron gun has been designed employing a flat-thermionic cathode to replace the existing Pierce-geometry gun. The flat cathode yields increased current with the same applied voltage and cathode area as the Pierce gun. The ISIS code simulations indicate a beam current of 1.5 kA at 600 kV. The new geometry also reduces the probability for high voltage breakdown in the A-K gap. A reentrant magnet captures the expanding electron beam and a bucking coil nulls cathode-tinge field. A third coil is used to optimize the extraction field profile and reduce the effect of nonlinear space charge on the beam emittance. Time-resolved measurements of beam current and voltage have been made. In addition, a streak camera was used to measure beam emittance and spatial profile. Comparisons of measurements with simulations are presented.
A flat-cathode thermionic injector for the PHERMEX Radiographic Facility
Kauppila, T.; Builta, L.; Burns, M.; Gregory, W.; Honaberger, D.; Watson, S. ); Hughes, T. )
1993-01-01
The PHERMEX (Pulsed High-Energy Radiographic Machine Emitting X-rays) standing-wave linear accelerator is a high-current electron beam generator used for flash-radiography. An improved electron gun has been designed employing a flat-thermionic cathode to replace the existing Pierce-geometry gun. The flat cathode yields increased current with the same applied voltage and cathode area as the Pierce gun. The ISIS code simulations indicate a beam current of 1.5 kA at 600 kV. The new geometry also reduces the probability for high voltage breakdown in the A-K gap. A reentrant magnet captures the expanding electron beam and a bucking coil nulls cathode-tinge field. A third coil is used to optimize the extraction field profile and reduce the effect of nonlinear space charge on the beam emittance. Time-resolved measurements of beam current and voltage have been made. In addition, a streak camera was used to measure beam emittance and spatial profile. Comparisons of measurements with simulations are presented.
Hall, G. N. Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L.
2014-11-15
Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.
Debono, Josephine C; Poulos, Ann E
2015-03-15
The aim of this study was to first evaluate the quality of studies investigating the diagnostic accuracy of radiographers as mammogram screen-readers and then to develop an adapted tool for determining the quality of screen-reading studies. A literature search was used to identify relevant studies and a quality evaluation tool constructed by combining the criteria for quality of Whiting, Rutjes, Dinnes et al. and Brealey and Westwood. This constructed tool was then applied to the studies and subsequently adapted specifically for use in evaluating quality in studies investigating diagnostic accuracy of screen-readers. Eleven studies were identified and the constructed tool applied to evaluate quality. This evaluation resulted in the identification of quality issues with the studies such as potential for bias, applicability of results, study conduct, reporting of the study and observer characteristics. An assessment of the applicability and relevance of the tool for this area of research resulted in adaptations to the criteria and the development of a tool specifically for evaluating diagnostic accuracy in screen-reading. This tool, with further refinement and rigorous validation can make a significant contribution to promoting well-designed studies in this important area of research and practice.
Hydrodynamic simulation of a lithium chloride salt system.
Eberle, C. S.; Herrmann, S. D.; Knighton, G. C.
1999-02-12
A fused lithium chloride salt system's constitutive properties were evaluated and compared to a number of fluid properties, and water was shown to be an excellent simulant of lithium chloride salt. With a simple flow model, the principal scaling term was shown to be a function of the kinematic viscosity. A water mock-up of the molten salt was also shown to be within a {+-}3% error in the scaling analysis. This made it possible to consider developing water scaled tests of the molten salt system. Accurate flow velocity and pressure measurements were acquired by developing a directional velocity probe. The device was constructed and calibrated with a repeatable accuracy of {+-}15%. This was verified by a detailed evaluation of the probe. Extensive flow measurements of the engineering scale mockup were conducted, and the results were carefully compared to radial flow patterns of a straight blade stirrer. The flow measurements demonstrated an anti-symmetric nature of the stirring, and many additional effects were also identified. The basket design was shown to prevent fluid penetration into the fuel baskets when external stirring was the flow mechanism.
Tung, Ryan C. Killgore, Jason P.; Hurley, Donna C.
2014-06-14
We present a method to correct for surface-coupled inertial and viscous fluid loading forces in contact resonance (CR) atomic force microscopy (AFM) experiments performed in liquid. Based on analytical hydrodynamic theory, the method relies on experimental measurements of the AFM cantilever's free resonance peaks near the sample surface. The free resonance frequencies and quality factors in both air and liquid allow reconstruction of a continuous hydrodynamic function that can be used to adjust the CR data in liquid. Validation experiments utilizing thermally excited free and in-contact spectra were performed to assess the accuracy of our approach. Results show that the method recovers the air frequency values within approximately 6%. Knowledge of fluid loading forces allows current CR analysis techniques formulated for use in air and vacuum environments to be applied to liquid environments. Our technique greatly extends the range of measurement environments available to CR-AFM.
Validation of Hydrodynamic Load Models Using CFD for the OC4-DeepCwind Semisubmersible: Preprint
Benitz, M. A.; Schmidt, D. P.; Lackner, M. A.; Stewart, G. M.; Jonkman, J.; Robertson, A.
2015-03-01
Computational fluid dynamics (CFD) simulations were carried out on the OC4-DeepCwind semi-submersible to obtain a better understanding of how to set hydrodynamic coefficients for the structure when using an engineering tool such as FAST to model the system. The focus here was on the drag behavior and the effects of the free-surface, free-ends and multi-member arrangement of the semi-submersible structure. These effects are investigated through code-to-code comparisons and flow visualizations. The implications on mean load predictions from engineering tools are addressed. The work presented here suggests that selection of drag coefficients should take into consideration a variety of geometric factors. Furthermore, CFD simulations demonstrate large time-varying loads due to vortex shedding, which FAST's hydrodynamic module, HydroDyn, does not model. The implications of these oscillatory loads on the fatigue life needs to be addressed.
Low torque hydrodynamic lip geometry for bi-directional rotation seals
Dietle, Lannie L.; Schroeder, John E.
2009-07-21
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.
Low torque hydrodynamic lip geometry for bi-directional rotation seals
Dietle, Lannie L.; Schroeder, John E.
2011-11-15
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.
Second-order discretization in space and time for radiation hydrodynamics
Edwards, J. D.; Morel, J. E.; Lowrie, R. B.
2013-07-01
We present a method for solving the equations of radiation hydrodynamics that is second-order accurate in space and time. This method combines the MUSCL-Hancock method for solving the Euler equations with the TR/BDF2 scheme in time for solving the equations of radiative transfer. We use an LDFEM to discretize the radiative transfer equations in space, which, though uncommon for radiation diffusion calculations, is a standard for radiation transport applications. We address the challenges inherent to using different spatial discretizations for the hydrodynamics and radiation and demonstrate how these may be overcome. We define our method for a 1-D model of compressible fluid dynamics coupled with grey radiation diffusion. Using the method of manufactured solutions, we show that the method is second-order accurate in space and time for both the equilibrium diffusion and streaming limit. (authors)
Gidaspow, D.
1996-04-01
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.
The source of elliptic flow and initial conditions for hydrodynamical calculations
Strottman, D.; Csernai, L.; Magas, V.
2000-08-01
A model for energy, pressure and flow velocity distributions at the beginning of relativistic heavy ion collisions is presented, which can be used as initial condition for hydrodynamical calculations. The results show that QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial condition may lead to the creation of antiflow or third flow component.
Starrfield, S.; Kenyon, S.; Truran, J.W.; Sparks, W.M.
1983-01-01
We have used a Lagrangian, hydrodynamic stellar-evolution computer code to evolve a thermonuclear runaway in the accreted hydrogen rich envelope of a 1.0M, 10-km neutron star. Our simulation produced an outburst which lasted about 2000 sec and peak effective temperature was 3 keV. The peak luminosity exceeded 2 x 10/sup 5/ L. A shock wave caused a precursor in the light curve which lasted 10/sup -5/ sec.
KIVA--Hydrodynamics Model for Chemically Reacting Flow with Spray - Energy
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Innovation Portal Vehicles and Fuels Vehicles and Fuels Industrial Technologies Industrial Technologies Energy Analysis Energy Analysis Find More Like This Return to Search KIVA--Hydrodynamics Model for Chemically Reacting Flow with Spray Los Alamos National Laboratory Contact LANL About This Technology Simulation of an experimental engine with DOHC quasi-symmetric pent-roof combustion chamber and 4 valves. Simulation of an experimental engine with DOHC quasi-symmetric pent-roof combustion
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Doss, F. W.; Kline, J. L.; Flippo, K. A.; Perry, T. S.; DeVolder, B. G.; Tregillis, I.; Loomis, E. N.; Merritt, E. C.; Murphy, T. J.; Welser-Sherrill, L.; et al
2015-04-17
An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 μm/ns shocks into a CH foam-filled shock tube (~ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment tomore » the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.« less
Doss, F. W.; Kline, J. L.; Flippo, K. A.; Perry, T. S.; DeVolder, B. G.; Tregillis, I.; Loomis, E. N.; Merritt, E. C.; Murphy, T. J.; Welser-Sherrill, L.; Fincke, J. R.
2015-04-17
An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 μm/ns shocks into a CH foam-filled shock tube (~ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment to the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.
Yang, Zhaoqing; Liu, Hedong; Khangaonkar, Tarang P.
2006-08-03
The Skagit River is the largest river in the Puget Sound estuarine system. It discharges about 39% of total sediment and more than 20% of freshwater into Puget Sound. The Skagit River delta provides rich estuarine and freshwater habitats for salmon and many other wildlife species. Over the past 150 years, economic development in the Skagit River delta has resulted in significant losses of wildlife habitat, particularly due to construction of dikes. Diked portion of the delta is known as Fir Island where irrigation practices for agriculture land over the last century has resulted in land subsidence. This has also caused reduced efficiency of drainage network and impeded fish passages through the area. In this study, a three-dimensional tidal circulation model was developed for the Skagit River delta to assist estuarine restoration in the Fir Island area. The hydrodynamic model used in the study is the Finite Volume Coastal Ocean Model (FVCOM). The hydrodynamic model was calibrated using field data collected from the study area specifically for the model development. Wetting and drying processes in the estuarine delta are simulated in the hydrodynamic model. The calibrated model was applied to simulate different restoration alternatives and provide guidance for estuarine restoration and management. Specifically, the model was used to help select and design configurations that would improve the supply of sediment and freshwater to the mudflats and tidal marsh areas outside of diked regions and then improve the estuarine habitats for salmon migration.
Doss, F. W.; Kline, J. L.; Flippo, K. A.; Perry, T. S.; DeVolder, B. G.; Tregillis, I.; Loomis, E. N.; Merritt, E. C.; Murphy, T. J.; Welser-Sherrill, L.; Fincke, J. R.
2015-04-17
An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 ?m/ns shocks into a CH foam-filled shock tube (~ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment to the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.
Donna Post Guillen; Daniel S. Wendt; Steven P. Antal; Michael Z. Podowski
2007-11-01
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.
Harrison, Alan K; Shashkov, Mikhail J; Fung, Jimmy; Canfield, Thomas R; Kamm, James R
2010-10-14
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.
Donna Post Guillen; Daniel S. Wendt
2007-11-01
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.
Karsch,F.; Kharzeev, D.; Molnar, K.; Petreczky, P.; Teaney, D.
2008-04-21
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.
Simulation and Analysis of Converging Shock Wave Test Problems
Ramsey, Scott D.; Shashkov, Mikhail J.
2012-06-21
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.
Akamatsu, Yukinao; Inutsuka, Shu-ichiro; Nonaka, Chiho; Department of Physics, Nagoya University, Nagoya 464-8602 ; Takamoto, Makoto; Max-Planck-Institut fr Kernphysik, Postfach 103980, 69029 Heidelberg
2014-01-01
In this article, we present a state-of-the-art algorithm for solving the relativistic viscous hydrodynamics equation with the QCD equation of state. The numerical method is based on the second-order Godunov method and has less numerical dissipation, which is crucial in describing of quarkgluon plasma in high-energy heavy-ion collisions. We apply the algorithm to several numerical test problems such as sound wave propagation, shock tube and blast wave problems. In sound wave propagation, the intrinsic numerical viscosity is measured and its explicit expression is shown, which is the second-order of spatial resolution both in the presence and absence of physical viscosity. The expression of the numerical viscosity can be used to determine the maximum cell size in order to accurately measure the effect of physical viscosity in the numerical simulation.
Hydrodynamic Simulation of the Columbia River, Hanford Reach, 1940--2004
Waichler, Scott R.; Perkins, William A.; Richmond, Marshall C.
2005-06-15
Many hydrological and biological problems in the Columbia River corridor through the Hanford Site require estimates of river stage (water surface elevation) or river flow and velocity. Systematic collection of river stage data at locations in the Hanford Reach began in 1991, but many environmental projects need river stage information at unmeasured locations or over longer time periods. The Modular Aquatic Simulation System 1D (MASS1), a one-dimensional, unsteady hydrodynamic and water quality model, was used to simulate the Columbia River from Priest Rapids Dam to McNary Dam from 1940 to 2004, providing estimates of water surface elevation, volumetric flow rate, and flow velocity at 161 locations on the Hanford Reach. The primary input data were bathymetric/topographic cross sections of the Columbia River channel, flow rates at Priest Rapids Dam, and stage at McNary Dam. Other inputs included Yakima River and Snake River inflows. Available flow data at a gaging station just below Priest Rapids Dam was mean daily flow from 1940 to 1986 and hourly thereafter. McNary dam was completed in 1957, and hourly stage data are available beginning in 1975. MASS1 was run at an hourly timestep and calibrated and tested using 1991--2004 river stage data from six Hanford Reach locations (areas 100B, 100N, 100D, 100H, 100F, and 300). Manning's roughness coefficient in the Reach above each river recorder location was adjusted using an automated genetic algorithm and gradient search technique in three separate calibrations, corresponding to different data subsets, with minimization of mean absolute error as the objective. The primary calibration was based on 1999, a representative year, and included all locations. The first alternative calibration also used all locations but was limited in time to a high-flow period during spring and early summer of 1997. The second alternative calibration was based on 1999 and included only 300 Area stage data. Model goodness-of-fit for all years
Simulating Rayleigh-Taylor (RT) instability using PPM hydrodynamics @scale on Roadrunner (u)
Woodward, Paul R; Dimonte, Guy; Rockefeller, Gabriel M; Fryer, Christopher L; Dimonte, Guy; Dai, W; Kares, R. J.
2011-01-05
The effect of initial conditions on the self-similar growth of the RT instability is investigated using a hydrodynamics code based on the piecewise-parabolic-method (PPM). The PPM code was converted to the hybrid architecture of Roadrunner in order to perform the simulations at extremely high speed and spatial resolution. This paper describes the code conversion to the Cell processor, the scaling studies to 12 CU's on Roadrunner and results on the dependence of the RT growth rate on initial conditions. The relevance of the Roadrunner implementation of this PPM code to other existing and anticipated computer architectures is also discussed.
Galactic scale gas flows in colliding galaxies: 3-Dimensional, N-body/hydrodynamics experiments
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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
Two-fluid Hydrodynamic Model for Fluid-Flow Simulation in Fluid-Solids Systems
Energy Science and Technology Software Center (OSTI)
1994-06-20
FLUFIX is a two-dimensional , transient, Eulerian, and finite-difference program, based on a two-fluid hydrodynamic model, for fluid flow simulation in fluid-solids systems. The software is written in a modular form using the Implicit Multi-Field (IMF) numerical technique. Quantities computed are the spatial distribution of solids loading, gas and solids velocities, pressure, and temperatures. Predicted are bubble formation, bed frequencies, and solids recirculation. Applications include bubbling and circulating atmospheric and pressurized fluidized bed reactors, combustors,more » gasifiers, and FCC (Fluid Catalytic Cracker) reactors.« less
The Kozai-Lidov mechanism in hydrodynamical disks. II. Effects of binary and disk parameters
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Fu, Wen; Lubow, Stephen H.; Martin, Rebecca G.
2015-07-01
Martin et al. (2014b) showed that a substantially misaligned accretion disk around one component of a binary system can undergo global damped Kozai–Lidov (KL) oscillations. During these oscillations, the inclination and eccentricity of the disk are periodically exchanged. However, the robustness of this mechanism and its dependence on the system parameters were unexplored. In this paper, we use three-dimensional hydrodynamical simulations to analyze how various binary and disk parameters affect the KL mechanism in hydrodynamical disks. The simulations include the effect of gas pressure and viscosity, but ignore the effects of disk self-gravity. We describe results for different numerical resolutions,more » binary mass ratios and orbital eccentricities, initial disk sizes, initial disk surface density profiles, disk sound speeds, and disk viscosities. We show that the KL mechanism can operate for a wide range of binary-disk parameters. We discuss the applications of our results to astrophysical disks in various accreting systems.« less
Zakharov, Leonid E.; Li, Xujing
2015-06-15
This paper formulates the Tokamak Magneto-Hydrodynamics (TMHD), initially outlined by X. Li and L. E. Zakharov [Plasma Science and Technology 17(2), 97–104 (2015)] for proper simulations of macroscopic plasma dynamics. The simplest set of magneto-hydrodynamics equations, sufficient for disruption modeling and extendable to more refined physics, is explained in detail. First, the TMHD introduces to 3-D simulations the Reference Magnetic Coordinates (RMC), which are aligned with the magnetic field in the best possible way. The numerical implementation of RMC is adaptive grids. Being consistent with the high anisotropy of the tokamak plasma, RMC allow simulations at realistic, very high plasma electric conductivity. Second, the TMHD splits the equation of motion into an equilibrium equation and the plasma advancing equation. This resolves the 4 decade old problem of Courant limitations of the time step in existing, plasma inertia driven numerical codes. The splitting allows disruption simulations on a relatively slow time scale in comparison with the fast time of ideal MHD instabilities. A new, efficient numerical scheme is proposed for TMHD.
Hydrodynamic modeling for corrosion control in the oil and gas industry
Palacios, C.A.; Morales, J.L.
1995-10-01
This article describes a methodology used to select and establish corrosion control programs. These include corrosion rate predictions using well known correlations for flowing systems, materials selection, optimization of inhibitors and corrosion monitoring techniques. The methodology characterizes internal corrosion phenomenon integrating the hydrodynamic conditions of the flow (flow velocities, flow pattern, liquid holdups, and where the condensation is taking place within a pipeline) with those that predict corrosion rates. It can be applied in the whole oil/gas production system, including subsurface and surface equipment. The methodology uses single and two phase flow modeling techniques to: (1) optimize the entire production system to obtain the most efficient objective flow rate, taking into consideration the corrosive/erosive nature of the produced fluids and (2) characterize the corrosion nature of oil and gas transmission lines. As an example of its use, a characterization of corrosion nature of a gas transmission line is described. The hydrodynamic simulation was performed using commercially available simulators, and the corrosion rates were determined using published correlations. Results using this methodology allowed for corrosion control strategies, protection and monitoring criteria, and inhibition optimization.
Peterson, J. L.; Clark, D. S.; Suter, L. J.; Masse, L. P.
2014-09-15
Defects on inertial confinement fusion capsule surfaces can seed hydrodynamic instability growth and adversely affect capsule performance. The dynamics of shocks launched during the early period of x-ray driven National Ignition Facility (NIF) implosions determine whether perturbations will grow inward or outward at peak implosion velocity and final compression. In particular, the strength of the first shock, launched at the beginning of the laser pulse, plays an important role in determining Richtmyer-Meshkov (RM) oscillations on the ablation front. These surface oscillations can couple to the capsule interior through subsequent shocks before experiencing Rayleigh-Taylor (RT) growth. We compare radiation hydrodynamic simulations of NIF implosions to analytic theories of the ablative RM and RT instabilities to illustrate how early time laser strength can alter peak velocity growth. We develop a model that couples the RM and RT implosion phases and captures key features of full simulations. We also show how three key parameters can control the modal demarcation between outward and inward growth.
Selective evaporation of focusing fluid in two-fluid hydrodynamic print head.
Keicher, David M.; Cook, Adam W.
2014-09-01
The work performed in this project has demonstrated the feasibility to use hydrodynamic focusing of two fluid steams to create a novel micro printing technology for electronics and other high performance applications. Initial efforts focused solely on selective evaporation of the sheath fluid from print stream provided insight in developing a unique print head geometry allowing excess sheath fluid to be separated from the print flow stream for recycling/reuse. Fluid flow models suggest that more than 81 percent of the sheath fluid can be removed without affecting the print stream. Further development and optimization is required to demonstrate this capability in operation. Print results using two-fluid hydrodynamic focusing yielded a 30 micrometers wide by 0.5 micrometers tall line that suggests that the cross-section of the printed feature from the print head was approximately 2 micrometers in diameter. Printing results also demonstrated that complete removal of the sheath fluid is not necessary for all material systems. The two-fluid printing technology could enable printing of insulated conductors and clad optical interconnects. Further development of this concept should be pursued.
Casner, A. Masse, L.; Huser, G.; Galmiche, D.; Liberatore, S.; Riazuelo, G.; Delorme, B.; Martinez, D.; Remington, B.; Smalyuk, V. A.; Igumenshchev, I.; Michel, D. T.; Froula, D.; Seka, W.; Goncharov, V. N.; Olazabal-Loumé, M.; Nicolaï, Ph.; Breil, J.; Tikhonchuk, V. T.; Fujioka, S.; and others
2014-12-15
Understanding and mitigating hydrodynamic instabilities and the fuel mix are the key elements for achieving ignition in Inertial Confinement Fusion. Cryogenic indirect-drive implosions on the National Ignition Facility have evidenced that the ablative Rayleigh-Taylor Instability (RTI) is a driver of the hot spot mix. This motivates the switch to a more flexible higher adiabat implosion design [O. A. Hurricane et al., Phys. Plasmas 21, 056313 (2014)]. The shell instability is also the main candidate for performance degradation in low-adiabat direct drive cryogenic implosions [Goncharov et al., Phys. Plasmas 21, 056315 (2014)]. This paper reviews recent results acquired in planar experiments performed on the OMEGA laser facility and devoted to the modeling and mitigation of hydrodynamic instabilities at the ablation front. In application to the indirect-drive scheme, we describe results obtained with a specific ablator composition such as the laminated ablator or a graded-dopant emulator. In application to the direct drive scheme, we discuss experiments devoted to the study of laser imprinted perturbations with special phase plates. The simulations of the Richtmyer-Meshkov phase reversal during the shock transit phase are challenging, and of crucial interest because this phase sets the seed of the RTI growth. Recent works were dedicated to increasing the accuracy of measurements of the phase inversion. We conclude by presenting a novel imprint mitigation mechanism based on the use of underdense foams. The foams induce laser smoothing by parametric instabilities thus reducing the laser imprint on the CH foil.
Hydrodynamic instability growth and mix experiments at the National Ignition Facility
Smalyuk, V. A.; Barrios, M.; Caggiano, J. A.; Casey, D. T.; Cerjan, C. J.; Clark, D. S.; Edwards, M. J.; Haan, S. W.; Hammel, B. A.; Hamza, A.; Hsing, W. W.; Hurricane, O.; Kroll, J.; Landen, O. L.; Lindl, J. D.; Ma, T.; McNaney, J. M.; Mintz, M.; Parham, T.; Peterson, J. L.; and others
2014-05-15
Hydrodynamic instability growth and its effects on implosion performance were studied at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. Implosion performance and mix have been measured at peak compression using plastic shells filled with tritium gas and containing embedded localized carbon-deuterium diagnostic layers in various locations in the ablator. Neutron yield and ion temperature of the deuterium-tritium fusion reactions were used as a measure of shell-gas mix, while neutron yield of the tritium-tritium fusion reaction was used as a measure of implosion performance. The results have indicated that the low-mode hydrodynamic instabilities due to surface roughness were the primary culprits for yield degradation, with atomic ablator-gas mix playing a secondary role. In addition, spherical shells with pre-imposed 2D modulations were used to measure instability growth in the acceleration phase of the implosions. The capsules were imploded using ignition-relevant laser pulses, and ablation-front modulation growth was measured using x-ray radiography for a shell convergence ratio of ∼2. The measured growth was in good agreement with that predicted, thus validating simulations for the fastest growing modulations with mode numbers up to 90 in the acceleration phase. Future experiments will be focused on measurements at higher convergence, higher-mode number modulations, and growth occurring during the deceleration phase.
Shao, Yan-Lin Faltinsen, Odd M.
2014-10-01
We propose a new efficient and accurate numerical method based on harmonic polynomials to solve boundary value problems governed by 3D Laplace equation. The computational domain is discretized by overlapping cells. Within each cell, the velocity potential is represented by the linear superposition of a complete set of harmonic polynomials, which are the elementary solutions of Laplace equation. By its definition, the method is named as Harmonic Polynomial Cell (HPC) method. The characteristics of the accuracy and efficiency of the HPC method are demonstrated by studying analytical cases. Comparisons will be made with some other existing boundary element based methods, e.g. Quadratic Boundary Element Method (QBEM) and the Fast Multipole Accelerated QBEM (FMA-QBEM) and a fourth order Finite Difference Method (FDM). To demonstrate the applications of the method, it is applied to some studies relevant for marine hydrodynamics. Sloshing in 3D rectangular tanks, a fully-nonlinear numerical wave tank, fully-nonlinear wave focusing on a semi-circular shoal, and the nonlinear wave diffraction of a bottom-mounted cylinder in regular waves are studied. The comparisons with the experimental results and other numerical results are all in satisfactory agreement, indicating that the present HPC method is a promising method in solving potential-flow problems. The underlying procedure of the HPC method could also be useful in other fields than marine hydrodynamics involved with solving Laplace equation.
Observation of hydrodynamic processes of radiation-ablated plasma in a small hole
Li, Hang; Kuang, Longyu; Jiang, Shaoen Ding, Yongkun; Song, Tianming; Yang, Jiamin Zhu, Tuo; Lin, Zhiwei; Zheng, Jianhua; Zhang, Haiying; Yu, Ruizhen; Liu, Shenye; Hu, Guangyue; Zhao, Bin; Zheng, Jian
2015-07-15
In the hohlraum used in laser indirect-drive inertial confinement fusion experiments, hydrodynamic processes of radiation-ablated high-Z plasma have a great effect on laser injection efficiency, radiation uniformity, and diagnosis of hohlraum radiation field from diagnostic windows (DW). To study plasma filling in the DWs, a laser-irradiated Ti disk was used to generate 2–5 keV narrow energy band X-ray as the intense backlighter source, and laser-produced X-ray in a hohlraum with low-Z foam tamper was used to heat a small hole surrounded by gold wall with 150 μm in diameter and 100 μm deep. The hydrodynamic movement of the gold plasma in the small hole was measured by an X-ray framing camera and the results are analyzed. Quantitative measurement of the plasma areal density distribution and evolution in the small hole can be used to assess the effect of plasma filling on the diagnosis from the DWs.
Zhao, Tongyang; Wang, Xiaogong; Jiang, Lei; Larson, Ronald G.
2014-07-01
We examine the accuracy of dissipative particle dynamics (DPD) simulations of polymers in dilute solutions with hydrodynamic interaction (HI), at the theta point, modeled by setting the DPD conservative interaction between beads to zero. We compare the first normal-mode relaxation time extracted from the DPD simulations with theoretical predictions from a normal-mode analysis for theta chains. We characterize the influence of bead inertia within the coil by a ratio L{sub m}/R{sub g}, where L{sub m} is the ballistic distance over which bead inertia is lost, and R{sub g} is the radius of gyration of the polymer coil, while the HI strength per bead h* is determined by the ratio of bead hydrodynamic radius (r{sub H}) to the equilibrium spring length. We show how to adjust h* through the spring length and monomer mass, and how to optimize the accuracy of DPD for fixed h* by increasing the friction coefficient (γ ≥ 9) and by incorporating a nonlinear distance dependence into the frictional interaction. Even with this optimization, DPD simulations exhibit deviations of over 20% from the theoretical normal-mode predictions for high HI strength with h* ≥ 0.20, for chains with as many as 100 beads, which is a larger deviation than is found for Stochastic rotation dynamics simulations for similar chains lengths and values of h*.
Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow
Donna Post Guillen
2009-07-01
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.
Johnson, Eric L.; Clabough, Tami S.; Peery, Christopher A.; Bennett, David H.; bjornn, Theodore C.; Caudill, Christopher C.; Richmond, Marshall C.
2007-11-01
Gas bubble disease (GBD) has been recognized for years as a potential problem for fishes in the Columbia River basin. GBD results from exposure to gas supersaturated water created by discharge over dam spillways. Spill typically creates a downstream plume of water with high total dissolved gas supersaturation (TDGS) that may be positioned along either shore or mid-channel, depending on dam operations. We obtained spatial data on fish migration paths and migration depths for 228 adult spring and summer Chinook salmon, Oncorhynchus tshawytscha, during 2000. Migration paths were compared to output from a two-dimensional hydrodynamic and dissolved gas model to estimate the potential for GBD expression and to test for behavioral avoidance of the high TDGS plume in unrestrained fish migrating under field conditions. Consistent with our previous estimates using single-location estimates of TDGS, we observed salmon swam sufficiently deep in the water column to receive complete hydrostatic compensation 95.9% of time spent in the Bonneville tailrace and 88.1% of the time in the Ice Harbor tailrace. The majority of depth uncompensated exposure occurred at TDGS levels > 115%. Adult spring and summer Chinook salmon tended to migrate near the shoreline. Adults moved into the high dissolved gas plume as often as they moved out of it downstream of Bonneville Dam, providing no evidence that adults moved laterally to avoid areas with elevated dissolved gas levels. The strong influence of dam operations on the position of the high-TDGS plume and shoreline-orientation behaviors of adults suggest that exposure of adult salmonids to high-TDGS conditions may be minimized using operational conditions that direct the plume mid-channel, particularly during periods of high discharge and spill. More generally, our approach illustrates the potential for combined field and modeling efforts to estimate the fine-scale environmental conditions encountered by fishes in natural and regulated rivers.
Ryblewski, Radoslaw; Florkowski, Wojciech
2010-08-15
We address the problem of whether the early thermalization and Hanbury-Brown-Twiss (HBT) puzzles in relativistic heavy-ion collisions may be solved by the assumption that the early dynamics of the produced matter is locally anisotropic. The hybrid model describing the purely transverse hydrodynamic evolution followed by the perfect-fluid hydrodynamic stage is constructed. The transition from the transverse to perfect-fluid hydrodynamics is described by the Landau matching conditions applied at a fixed proper time {tau}{sub tr}. The global fit to the RHIC data reproduces the soft hadronic observables (the pion, kaon, and the proton spectra, the pion and kaon elliptic flow, and the pion HBT radii) with the accuracy of about 20%. These results indicate that the assumption of the very fast thermalization may be relaxed. In addition, the presented model suggests that a large part of the inconsistencies between the theoretical and experimental HBT results may be removed.
Los Alamos National Laboratory to
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
to begin DARHT 2 operations January 29, 2008 Hydrodynamic testing at the frontier of science LOS ALAMOS, New Mexico, January 29, 2008- The Dual Axis Radiographic Hydrodynamic Test (DARHT) facility has officially become "dual" with authorization to begin full power operations of Axis 2, adding both new capability and higher energy to the unique accelerator facility. Los Alamos National Laboratory has received authorization from the National Nuclear Security Administration to begin
Calibration curves for some standard Gap Tests
Bowman, A.L.; Sommer, S.C.
1989-01-01
The relative shock sensitivities of explosive compositions are commonly assessed using a family of experiments that can be described by the generic term ''Gap Test.'' Gap tests include a donor charge, a test sample, and a spacer, or gap, between two explosives charges. The donor charge, gap material, and test dimensions are held constant within each different version of the gap test. The thickness of the gap is then varied to find the value at which 50% of the test samples will detonate. The gap tests measure the ease with a high-order detonation can be established in the test explosive, or the ''detonability,'' of the explosive. Test results are best reported in terms of the gap thickness at the 50% point. It is also useful to define the shock pressure transmitted into the test sample at the detonation threshold. This requires calibrating the gap test in terms of shock pressure in the gap as a function of the gap thickness. It also requires a knowledge of the shock Hugoniot of the sample explosive. We used the 2DE reactive hydrodynamic code with Forest Fire burn rates for the donor explosives to calculate calibration curves for several gap tests. The model calculations give pressure and particle velocity on the centerline of the experimental set-up and provide information about the curvature and pulse width of the shock wave. 10 refs., 1 fig.
Modifications of Carbonate Fracture Hydrodynamic Properties by CO{sub 2}-Acidified Brine Flow
Deng, Hang; Ellis, Brian R.; Peters, Catherine A.; Fitts, Jeffrey P.; Crandall, Dustin; Bromhal, Grant S.
2013-08-01
Acidic reactive flow in fractures is relevant in subsurface activities such as CO{sub 2} geological storage and hydraulic fracturing. Understanding reaction-induced changes in fracture hydrodynamic properties is essential for predicting subsurface flows such as leakage, injectability, and fluid production. In this study, x-ray computed tomography scans of a fractured carbonate caprock were used to create three dimensional reconstructions of the fracture before and after reaction with CO{sub 2}-acidified brine (Ellis et al., 2011, Greenhouse Gases: Sci. Technol., 1:248-260). As expected, mechanical apertures were found to increase substantially, doubling and even tripling in some places. However, the surface geometry evolved in complex ways including ‘comb-tooth’ structures created from preferential dissolution of calcite in transverse sedimentary bands, and the creation of degraded zones, i.e. porous calcite-depleted areas on reacted fracture surfaces. These geometric alterations resulted in increased fracture roughness, as measured by surface Z{sub 2} parameters and fractal dimensions D{sub f}. Computational fluid dynamics (CFD) simulations were conducted to quantify the changes in hydraulic aperture, fracture transmissivity and permeability. The results show that the effective hydraulic apertures are smaller than the mechanical apertures, and the changes in hydraulic apertures are nonlinear. Overestimation of flow rate by a factor of two or more would be introduced if fracture hydrodynamic properties were based on mechanical apertures, or if hydraulic aperture is assumed to change proportionally with mechanical aperture. The differences can be attributed, in part, to the increase in roughness after reaction, and is likely affected by contiguous transverse sedimentary features. Hydraulic apertures estimated by the 1D statistical model and 2D local cubic law (LCL) model are consistently larger than those calculated from the CFD simulations. In addition, a novel
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Forklift Safety Test Instructions: All Training and Testing Material is for LSU CAMD Users ... A minimum passing score is 80% (8 out of 10) This test can only be taken once in a thirty ...
Energy Science and Technology Software Center (OSTI)
2007-08-31
Lustre-tests is a package of regression tests for the Lustre file system containing I/O workloads representative of problems discovered on production systems.
Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang
2010-04-22
In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratorys high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric light detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of
Investigating the Magnetorotational Instability with Dedalus, and Open-Souce Hydrodynamics Code
Burns, Keaton J; /UC, Berkeley, aff SLAC
2012-08-31
The magnetorotational instability is a fluid instability that causes the onset of turbulence in discs with poloidal magnetic fields. It is believed to be an important mechanism in the physics of accretion discs, namely in its ability to transport angular momentum outward. A similar instability arising in systems with a helical magnetic field may be easier to produce in laboratory experiments using liquid sodium, but the applicability of this phenomenon to astrophysical discs is unclear. To explore and compare the properties of these standard and helical magnetorotational instabilities (MRI and HRMI, respectively), magnetohydrodynamic (MHD) capabilities were added to Dedalus, an open-source hydrodynamics simulator. Dedalus is a Python-based pseudospectral code that uses external libraries and parallelization with the goal of achieving speeds competitive with codes implemented in lower-level languages. This paper will outline the MHD equations as implemented in Dedalus, the steps taken to improve the performance of the code, and the status of MRI investigations using Dedalus.
Charles Reece; John Mammosser; Jun Ortega
2008-02-12
Multi-cell niobium cavities often obtain the highest performance levels after having been subjected to an electropolishing (EP) process. The horizontal EP process first developed at KEK/Nomura Plating for TRISTAN[1] cavities is being applied to TESLA-style cavities and other structures for the XFEL and ILC R&D. Jefferson Lab is presently carrying this activity in the US. Because the local electropolishing current density is highly temperature dependent, we have created using CFDesign a full-scale hydrodynamic model which simulates the various thermal conditions present during 9-cell cavity electropolishing. The results of these simulations are compared with exterior surface temperature data gathered during ILC cavity EP at JLab. Having benchmarked the simulation, we explore the affect of altered boundary conditions in order to evaluate potentially beneficial modifications to the current standard process.
Smoothed Particle Hydrodynamics pore-scale simulations of unstable immiscible flow in porous media
Bandara, Dunusinghe Mudiyanselage Uditha C.; Tartakovsky, Alexandre M.; Oostrom, Martinus; Palmer, Bruce J.; Grate, Jay W.; Zhang, Changyong
2013-12-01
We have conducted a series of high-resolution numerical experiments using the Pair-Wise Force Smoothed Particle Hydrodynamics (PF-SPH) multiphase flow model. First, we derived analytical expressions relating parameters in the PF-SPH model to the surface tension and static contact angle. Next, we used the model to study viscous fingering, capillary fingering, and stable displacement of immiscible fluids in porous media for a wide range of capillary numbers and viscosity ratios. We demonstrated that the steady state saturation profiles and the boundaries of viscous fingering, capillary fingering, and stable displacement regions compare favorably with micromodel laboratory experimental results. For displacing fluid with low viscosity, we observed that the displacement pattern changes from viscous fingering to stable displacement with increasing injection rate. When a high viscosity fluid is injected, transition behavior from capillary fingering to stable displacement occurred as the flow rate was increased. These observation also agree with the results of the micromodel laboratory experiments.
Andronov, V.A.; Zhidov, I.G.; Meskov, E.E.; Nevmerzhitskii, N.V.; Nikiforov, V.V.; Razin, A.N.; Rogatchev, V.G.; Tolshmyakov, A.I.; Yanilkin, Yu.V.
1995-02-01
This report describes an extensive program of investigations conducted at Arzamas-16 in Russia over the past several decades. The focus of the work is on material interface instability and the mixing of two materials. Part 1 of the report discusses analytical and computational studies of hydrodynamic instabilities and turbulent mixing. The EGAK codes are described and results are illustrated for several types of unstable flow. Semiempirical turbulence transport equations are derived for the mixing of two materials, and their capabilities are illustrated for several examples. Part 2 discusses the experimental studies that have been performed to investigate instabilities and turbulent mixing. Shock-tube and jelly techniques are described in considerable detail. Results are presented for many circumstances and configurations.
Dudukovic, M.P.; Fan, L.S.; Chang, Min
1997-05-01
The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research and Engineering Company is to improve the basis 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. The first year of this three year program was spent on developing and tuning the experimental tools that can provide accurate measurement of pertinent hydrodynamic quantities, such as velocity field and holdup distribution, for validation of hydrodynamic models. Advances made in preparing the unique Computer Automated Radioactive Particle Tracing (CARPT) technique for use in high pressure systems are described in this report The work done on developing a reliable beat transfer coefficient measurement probe at operating conditions of interest is also described. Finally, the work done in preparing the Exxon pilot plant facilities for high pressure runs and pertinent hydrodynamic measurements is outlined together with preliminary studies of matching the fluid dynamics program predictions and data in a two dimensional column.
Barz, H.W.; Csernai, L.P.; Greiner, W.
1982-08-01
The collision process is described by hydrodynamical equations. The escape of nucleons which do not take part in the thermal equilibrium are considered by including drain terms in these equations. The energy spectra of the escaped nucleons and of nucleons evaporated after the break up of the fluid are compared.
CTH simulation of PBX-9501 Taylor tests /
Koby, Joseph R.
2011-09-01
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.
Sai K. Mylavarapu; Xiaodong Sun; Richard E. Glosup; Richard N. Christensen; Michael W. Patterson
2014-04-01
In high-temperature gas-cooled reactors, such as a very high temperature reactor (VHTR), an intermediate heat exchanger (IHX) is required to efficiently transfer the core thermal output to a secondary fluid for electricity generation with an indirect power cycle and/or process heat applications. Currently, there is no proven high-temperature (750800 C or higher) compact heat exchanger technology for high-temperature reactor design concepts. In this study, printed circuit heat exchanger (PCHE), a potential IHX concept for high-temperature applications, has been investigated for their heat transfer and pressure drop characteristics under high operating temperatures and pressures. Two PCHEs, each having 10 hot and 10 cold plates with 12 channels (semicircular cross-section) in each plate are fabricated using Alloy 617 plates and tested for their performance in a high-temperature helium test facility (HTHF). The PCHE inlet temperature and pressure were varied from 85 to 390 C/1.02.7 MPa for the cold side and 208790 C/1.02.7 MPa for the hot side, respectively, while the mass flow rate of helium was varied from 15 to 49 kg/h. This range of mass flow rates corresponds to PCHE channel Reynolds numbers of 950 to 4100 for the cold side and 900 to 3900 for the hot side (corresponding to the laminar and laminar-to-turbulent transition flow regimes). The obtained experimental data have been analyzed for the pressure drop and heat transfer characteristics of the heat transfer surface of the PCHEs and compared with the available models and correlations in the literature. In addition, a numerical treatment of hydrodynamically developing and hydrodynamically fully-developed laminar flow through a semicircular duct is presented. Relations developed for determining the hydrodynamic entrance length in a semicircular duct and the friction factor (or pressure drop) in the hydrodynamic entry length region for laminar flow through a semicircular duct are given. Various hydrodynamic
Energy Science and Technology Software Center (OSTI)
2001-09-01
Nettest is a secure, real-time network utility. The nettest framework is designed to incorporate existing and new network tests, and be run as a daemon or an interactive process. Requests for network tests are received via a SSL connection or the user interface and are authorized using a ACL list (in the future authorization using Akenti will also be supported). For tests that require coordination between the two ends of the test, Nettest establishes anmore » SSL connection to accomplish this coordination. A test between two remote computers can be requested via the user interlace if the Nettest daemon is running on both remote machines and the user is authorized. Authorization for the test is through a chain of trust estabtished by the nettest daemons. Nettest is responsible for determining if the test request is authorized, but it does nothing further to secure the test once the test is running. Currently the Nettest framework incorporates lperf-vl.2, a simple ping type test, and a tuned TCP test that uses a given required throughput and ping results to determine the round trip time to set a buffer size (based on the delay bandwidth product) and then performs an iperf TCP throughput test. Additional network test tools can be integrated into the Nettest framework in the future.« less
Shestakov, A I; Offner, S R
2006-09-21
We present a scheme to solve the nonlinear multigroup radiation diffusion (MGD) equations. The method is incorporated into a massively parallel, multidimensional, Eulerian radiation-hydrodynamic code with adaptive mesh refinement (AMR). The patch-based AMR algorithm refines in both space and time creating a hierarchy of levels, coarsest to finest. The physics modules are time-advanced using operator splitting. On each level, separate 'level-solve' packages advance the modules. Our multigroup level-solve adapts an implicit procedure which leads to a two-step iterative scheme that alternates between elliptic solves for each group with intra-cell group coupling. For robustness, we introduce pseudo transient continuation ({Psi}tc). We analyze the magnitude of the {Psi}tc parameter to ensure positivity of the resulting linear system, diagonal dominance and convergence of the two-step scheme. For AMR, a level defines a subdomain for refinement. For diffusive processes such as MGD, the refined level uses Dirichet boundary data at the coarse-fine interface and the data is derived from the coarse level solution. After advancing on the fine level, an additional procedure, the sync-solve (SS), is required in order to enforce conservation. The MGD SS reduces to an elliptic solve on a combined grid for a system of G equations, where G is the number of groups. We adapt the 'partial temperature' scheme for the SS; hence, we reuse the infrastructure developed for scalar equations. Results are presented. We consider a multigroup test problem with a known analytic solution. We demonstrate utility of {Psi}tc by running with increasingly larger timesteps. Lastly, we simulate the sudden release of energy Y inside an Al sphere (r = 15 cm) suspended in air at STP. For Y = 11 kT, we find that gray radiation diffusion and MGD produce similar results. However, if Y = 1 MT, the two packages yield different results. Our large Y simulation contradicts a long-standing theory and demonstrates
Shestakov, A I; Offner, S R
2007-03-02
We present a scheme to solve the nonlinear multigroup radiation diffusion (MGD) equations. The method is incorporated into a massively parallel, multidimensional, Eulerian radiation-hydrodynamic code with adaptive mesh refinement (AMR). The patch-based AMR algorithm refines in both space and time creating a hierarchy of levels, coarsest to finest. The physics modules are time-advanced using operator splitting. On each level, separate 'level-solve' packages advance the modules. Our multigroup level-solve adapts an implicit procedure which leads to a two-step iterative scheme that alternates between elliptic solves for each group with intra-cell group coupling. For robustness, we introduce pseudo transient continuation ({Psi}tc). We analyze the magnitude of the {Psi}tc parameter to ensure positivity of the resulting linear system, diagonal dominance and convergence of the two-step scheme. For AMR, a level defines a subdomain for refinement. For diffusive processes such as MGD, the refined level uses Dirichet boundary data at the coarse-fine interface and the data is derived from the coarse level solution. After advancing on the fine level, an additional procedure, the sync-solve (SS), is required in order to enforce conservation. The MGD SS reduces to an elliptic solve on a combined grid for a system of G equations, where G is the number of groups. We adapt the 'partial temperature' scheme for the SS; hence, we reuse the infrastructure developed for scalar equations. Results are presented. We consider a multigroup test problem with a known analytic solution. We demonstrate utility of {Psi}tc by running with increasingly larger timesteps. Lastly, we simulate the sudden release of energy Y inside an Al sphere (r = 15 cm) suspended in air at STP. For Y = 11 kT, we find that gray radiation diffusion and MGD produce similar results. However, if Y = 1 MT, the two packages yield different results. Our large Y simulation contradicts a long-standing theory and demonstrates
The Effect of Roll Waves on the Hydrodynamics of Falling Films Observed in Vertical Column Absorbers
Miller, W.A.
2001-06-28
A thin falling film is well suited to simultaneous heat and mass transfer because of the small thermal resistance through the film and because of the large contact surface achievable at low flow rates. The film enters as a smooth laminar flow and quickly transitions into small-amplitude wavy flow. The waves grown in length and amplitude and are identified as roll waves. This flow regime is termed wavy-laminar flow, and modern heat and mass transfer equipment operate in this complicated transition regime. Research published in open literature has shown the mass flow rate in the rollwaves to be about 10 to 20 times greater than that in the laminar substrate. As the film fully develops, the waves grow in mass and the film substrate thins because fluid is swept from the substrate by the secondary flows of the roll wave. Many studies have been conducted to measure and correlate the film thickness of wavy-laminar flows. Literature data show that Nusselt's theory for smooth laminar flow can over predict the film thickness by as much as 20% for certain wavy-laminar flow conditions. The hydrodynamics of falling films were therefore studied to measure the film thickness of a free-surface falling film and to better understand the parameters that affect the variations of the film thickness. A flow loop was set up for measuring the thickness, wave amplitude,and frequency of a film during hydrodynamic flow. Decreasing the pipe diameter caused the amplitude of the wavy flow to diminish. Measurements monitored from stations along the falling film showed a thinning of film thickness. Fully developed flow required large starting lengths of about 0.5 m. The film thickness increases as the Reynolds number (Re) increases. Increasing the Kapitza number (Ka) causes a decrease in the film thickness. Regression analysis showed that the Re and Ka numbers described the data trends in wavy-laminar flow. Rather than correlating the Re number in discrete ranges of the Ka number as earlier
Oliva, Eduardo; Zeitoun, Philippe; Sebban, Stephan; Velarde, Pedro; Portillo, David; Fajardo, Marta; Cassou, Kevin; Ros, David; Le Pape, Sebastien
2010-11-15
Plasma-based seeded soft-x-ray lasers have the potential to generate high energy and highly coherent short pulse beams. Due to their high density, plasmas created by the interaction of an intense laser with a solid target should store the highest amount of energy density among all plasma amplifiers. Our previous numerical work with a two-dimensional (2D) adaptive mesh refinement hydrodynamic code demonstrated that careful tailoring of plasma shapes leads to a dramatic enhancement of both soft-x-ray laser output energy and pumping efficiency. Benchmarking of our 2D hydrodynamic code in previous experiments demonstrated a high level of confidence, allowing us to perform a full study with the aim of the way for 10-100 {mu}J seeded soft-x-ray lasers. In this paper, we describe in detail the mechanisms that drive the hydrodynamics of plasma columns. We observed transitions between narrow plasmas, where very strong bidimensional flow prevents them from storing energy, to large plasmas that store a high amount of energy. Millimeter-sized plasmas are outstanding amplifiers, but they have the limitation of transverse lasing. In this paper, we provide a preliminary solution to this problem.
Kok Yan Chan, G.; Sclavounos, P. D.; Jonkman, J.; Hayman, G.
2015-04-02
A hydrodynamics computer module was developed for the evaluation of the linear and nonlinear loads on floating wind turbines using a new fluid-impulse formulation for coupling with the FAST program. The recently developed formulation allows the computation of linear and nonlinear loads on floating bodies in the time domain and avoids the computationally intensive evaluation of temporal and nonlinear free-surface problems and efficient methods are derived for its computation. The body instantaneous wetted surface is approximated by a panel mesh and the discretization of the free surface is circumvented by using the Green function. The evaluation of the nonlinear loads is based on explicit expressions derived by the fluid-impulse theory, which can be computed efficiently. Computations are presented of the linear and nonlinear loads on the MIT/NREL tension-leg platform. Comparisons were carried out with frequency-domain linear and second-order methods. Emphasis was placed on modeling accuracy of the magnitude of nonlinear low- and high-frequency wave loads in a sea state. Although fluid-impulse theory is applied to floating wind turbines in this paper, the theory is applicable to other offshore platforms as well.