National Library of Energy BETA

Sample records for tidal analysis flow

  1. Dissecting the pressure field in tidal flow

    E-Print Network [OSTI]

    amplitude [N x 107 ] phase relative to the velocity [deg] power [W x107 ] 1 2 3 4 tidal excursion parameterDissecting the pressure field in tidal flow past a headland: When is form drag "real?" Sally Warner waves eddies H L LHH H L L LH #12;Numerical model Gaussian-shaped headland Barotropic tidal velocity D L

  2. Dissecting the pressure field in tidal flow

    E-Print Network [OSTI]

    Dissecting the pressure field in tidal flow past a headland: When is form drag "real?" Sally Warner of oscillating flow H L HL velocity form drag power average power floodslack work done on system #12;0 0 0 0 90 180 270 360 90 180 270 360 0 degrees Drag of oscillating flow H L HL velocity form drag power average

  3. Tidal analysis of water level in continental boreholes Version 2.2

    E-Print Network [OSTI]

    Brodsky, Emily

    tidal analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.3.1 The "credo

  4. Modeling tidal flow in the Great Bay Estuary, New Hampshire, using a depth averaged

    E-Print Network [OSTI]

    Modeling tidal flow in the Great Bay Estuary, New Hampshire, using a depth averaged flooding, University of New Hampshire, USA. 2 Numerical Methods Lab., Dartmouth College, USA. 3 Ocean Process Analysis Lab., University of New Hampshire, USA. Abstract Current, sea level and bed load transport

  5. Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT

    E-Print Network [OSTI]

    Winant, Clinton D.

    Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT Integrative-dimensional tidal circulation in an elongated basin of arbitrary depth is described with a linear, constant parcels tend to corkscrew into and out of the basin in a tidal period. The axial flow is only weakly

  6. Enhancing tidal harmonic analysis: Robust (hybrid L1 ) solutions

    E-Print Network [OSTI]

    Hickey, Barbara

    Enhancing tidal harmonic analysis: Robust (hybrid L1 =L2 ) solutions Keith E. Leffler Ã, David A 24 February 2008 Accepted 28 April 2008 Keywords: Tides Tidal analysis Harmonic analysis Robust is calculated from the power spectrum of the residual, a calculation that filters broad spectrum noise

  7. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01

    M. C. 2006 An estimate of tidal energy lost to turbulence atcant loss of low-mode tidal energy at 28.9 ? . Geophys. Res.of turbulent kinetic energy over a tidal cycle. Maximum T KE

  8. Internal hydraulic jumps and overturning generated by tidal flow over a tall steep ridge

    E-Print Network [OSTI]

    Klymak, Jody M.

    that tidal energy is both converted into internal waves, which radiate away from the topography, and used of tidal mixing for global climate models, the physical processes governing the transfer of energy fromInternal hydraulic jumps and overturning generated by tidal flow over a tall steep ridge Sonya Legg

  9. Virtual Seafloor Reduces Internal Wave Generation by Tidal Flow Likun Zhang*

    E-Print Network [OSTI]

    the applicability of linear theory to global predictions of the conversion of tidal energy into internal wave energy of the energy budget of the oceans requires a determination of the efficiency of conversion of tidal energyVirtual Seafloor Reduces Internal Wave Generation by Tidal Flow Likun Zhang* and Harry L. Swinney

  10. Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets 

    E-Print Network [OSTI]

    Whilden, Kerri Ann

    2010-10-12

    OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE August 2009 Major Subject: Ocean... Engineering LABORATORY ANALYSIS OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE Approved...

  11. ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

    This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.

  12. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01

    Flow over sloping topography including streamwise vari-5 Flow over sloping topography without streamwise vari-of internal waves at sloping topography. Here, C p denotes

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

    E-Print Network [OSTI]

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

    2015-01-01

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

  14. Asymmetric mixing transport: a horizontal transport mechanism for sinking plankton and sediment in tidal flows

    E-Print Network [OSTI]

    Pringle, James "Jamie"

    Asymmetric mixing transport: a horizontal transport mechanism for sinking plankton and sediment in tidal flows James M. Pringle1 and Peter J.S. Franks2 SIO-UCSD, Mail Stop 0218 La Jolla, California 92093-0218 Running Head: Asymmetric Mixing Transport and Plankton 1 jmpringle@ucsd.edu 2 pfranks@ucsd.edu 1 #12

  15. Earth Tidal Analysis | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower VenturesInformation9)askDoubleEERE -ESolar IncEagleAnalysis Jump to:

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

    E-Print Network [OSTI]

    Hotaka Shiokawa; Julian H. Krolik; Roseanne M. Cheng; Tsvi Piran; Scott C. Noble

    2015-01-18

    We study how the matter dispersed when a supermassive black hole tidally disrupts a star joins an accretion flow. Combining a relativistic hydrodynamic simulation of the stellar disruption with a relativistic hydrodynamics simulation of the tidal debris motion, we track such a system until ~80% of the stellar mass bound to the black hole has settled into an accretion flow. Shocks near the stellar pericenter and also near the apocenter of the most tightly-bound debris dissipate orbital energy, but only enough to make the characteristic radius comparable to the semi-major axis of the most-bound material, not the tidal radius as previously thought. The outer shocks are caused by post-Newtonian effects, both on the stellar orbit during its disruption and on the tidal forces. Accumulation of mass into the accretion flow is non-monotonic and slow, requiring ~3--10x the orbital period of the most tightly-bound tidal streams, while the inflow time for most of the mass may be comparable to or longer than the mass accumulation time. Deflection by shocks does, however, remove enough angular momentum and energy from some mass for it to move inward even before most of the mass is accumulated into the accretion flow. Although the accretion rate rises sharply and then decays roughly as a power-law, its maximum is ~0.1x the previous expectation, and the duration of the peak is ~5x longer than previously predicted. The geometric mean of the black hole mass and stellar mass inferred from a measured event timescale is therefore ~0.2x the value given by classical theory.

  17. Analysis of tidal current observations over the northeastern shelf of the Gulf of Mexico 

    E-Print Network [OSTI]

    Durham, Donald L

    1967-01-01

    LIST OF FIGURES Chapter TABLE OF CONTENTS Page vi vii IV INTRODUCTION A. Statement of Problem B. Literature Review 1. Tidal Current Theory 2. Tidal Current Observations INSTRUMENTATION AND DATA COLLECTION A. Selection and Modification... of Equipment B. September 1965 Survey DATA ANALYSIS AND RESULTS A. The Surface Tide 1. General 2. Gulf of Mexico B. Current Components C. Spectral Analysis D. Harmonic Analysis E. Tidal Ellipse F, Temperature CONCLUSIONS 1 1 2 2 11 15 15 21...

  18. Hydrodynamic analysis of a vertical axis tidal current turbine 

    E-Print Network [OSTI]

    Gretton, Gareth I.

    2009-01-01

    Tidal currents can be used as a predictable source of sustainable energy, and have the potential to make a useful contribution to the energy needs of the UK and other countries with such a resource. One of the technologies ...

  19. Characterization of mean velocity and flow structures in rivers and tidal flow is crucial for the annual energy production estimation and

    E-Print Network [OSTI]

    Siefert, Chris

    · Characterization of mean velocity and flow structures in rivers and tidal flow is crucial for the annual energy production estimation and structural design of MHK devices. · ADCP moving vessel. FV data This research was funded by the U.S. Department of Energy under Contract DE-AC05-00OR22725. 5

  20. Internal wave and boundary current generation by tidal flow over topography Amadeus Dettner, Harry L. Swinney, and M. S. Paoletti

    E-Print Network [OSTI]

    Texas at Austin. University of

    Internal wave and boundary current generation by tidal flow over topography Amadeus Dettner, Harry turbulence and small-scale internal waves above deep-ocean topography Phys. Fluids 25, 106604 (2013); 10.1063/1.4826888 Topographically induced internal solitary waves in a pycnocline: Secondary generation and selection criteria Phys

  1. Water gate array for current flow or tidal movement pneumatic harnessing system

    DOE Patents [OSTI]

    Gorlov, Alexander M. (Brookline, MA)

    1991-01-01

    The invention, which provides a system for harnessing power from current flow or tidal movement in a body of water, comprises first and second hydro-pneumatic chambers each having ingress and egress below the water surface near the river or ocean floor and water gates operative to open or seal the ports to the passage of water. In an exemplary embodiment, the gates are sychronized by shafts so that the ingress ports of each chamber are connected to the egress ports of each other chamber. Thus, one set of gates is closed, while the other is open, thereby allowing water to flow into one chamber and build air pressure therein and allowing water to flow out of the other chamber and create a partial vacuum therein. A pipe connects the chambers, and an air turbine harnesses the air movement within the pipe. When water levels are equilibrated, the open set of gates is closed by a counterweight, and the other set is allowed to open by natural force of the water differential. The water gates may be comprised of a plurality of louvers which are ganged for simultaneous opening and closing. The system is designed to operate with air turbines or other pneumatic devices. Its design minimizes construction cost and environmental impact, yet provides a clean renewable energy source.

  2. Tidal Energy Research

    SciTech Connect (OSTI)

    Stelzenmuller, Nickolas; Aliseda, Alberto; Palodichuk, Michael; Polagye, Brian; Thomson, James; Chime, Arshiya; Malte, Philip

    2014-03-31

    This technical report contains results on the following topics: 1) Testing and analysis of sub-scale hydro-kinetic turbines in a flume, including the design and fabrication of the instrumented turbines. 2) Field measurements and analysis of the tidal energy resource and at a site in northern Puget Sound, that is being examined for turbine installation. 3) Conceptual design and performance analysis of hydro-kinetic turbines operating at high blockage ratio, for use for power generation and flow control in open channel flows.

  3. Fourier and autocorrelation analysis of estuarine tidal rhythmites, lower Breathitt Formation (Pennsylvania), eastern Kentucky, USA

    SciTech Connect (OSTI)

    Martino, R.L.; Sanderson, D.D. (Marshall Univ., Huntington, WV (United States))

    1993-01-01

    Outcrops of the Pennsylvanian Breathitt Formation in eastern Kentucky reveal a rhythmic pattern of siliciclastic sedimentation in a marginal marine coastal setting. A 15-23 m thick stratigraphic interval of thinly interbedded, fine sandstone and shale displays tidally generated features such as flaser and wavy current ripple bedding, bipolar paleocurrents, and cyclic thickening and thinning of mud-draped sandstone layers. A statistical analysis of sand layer thickness was carried out using shale partings as bounding surfaces for the individual sand units. Fourier and autocorrelation analyses were performed on two vertical sequences containing a total of over 2,100 layers. The results reveal the presence of four cycles of thickness variation. First-order cycles consist of alternating thick-thin sand layers. These daily couplets may reflect unequal flood and ebb currents during a single tidal cycle or dominant and subordinate tidal deposits in an ebb or flood dominated semidiurnal or mixed system. Second-order cycles typically consist of 11-14 sand layers and reflect spring-neap variations in tidal range and current velocities. Third-order cycles are usually composed of 24-35 layers and are formed in response to monthly variations in tidal range resulting from the ellipticity of the moon's orbit. Fourth-order cycles generally contain about 150 layers (range, 100-166) and were caused by seasonal maxima in tidal range associated with the solstice (winter, summer) and seasonal minima associated with the equinox (spring, fall).

  4. Category:Earth Tidal Analysis | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,Cammack Village,8199089°,AnalyticalCuttings AnalysisDownholeEZFeedEarth

  5. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, J.A.

    1997-07-01

    A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

  6. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA)

    1997-01-01

    A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

  7. Coherent Structures in Turbulent Flows: Experimental Studies on the Turbulence of Multiphase Plumes and Tidal Vortices 

    E-Print Network [OSTI]

    Bryant, Duncan Burnette

    2011-08-08

    stream_source_info BRYANT-DISSERTATION.pdf.txt stream_content_type text/plain stream_size 163756 Content-Encoding ISO-8859-1 stream_name BRYANT-DISSERTATION.pdf.txt Content-Type text/plain; charset=ISO-8859..., the turbulent energy spectra in inertial particle plumes followed the same modulation as the bubble plumes. PIV experiments from the tidal starting-jet vortices detail the influence of a finite channel length using identified vortice. The results show...

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

    SciTech Connect (OSTI)

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

    2014-04-30

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

  9. Internal wave and boundary current generation by tidal flow over topography Amadeus Dettner, Harry L. Swinney, and M. S. Paoletti

    E-Print Network [OSTI]

    to characterize the conversion of tidal energy to radiated internal wave power. Whether the hydrostatic ( , shape)/SIW, where Ptide is the effective tidal power that interacts with the topography, and /8 of the oceans. Therefore, it is useful to measure the total power PIW converted from barotropic tidal motions

  10. Mathematical Model Analysis for Hg Flow

    E-Print Network [OSTI]

    McDonald, Kirk

    Mathematical Model Analysis for Hg Flow Yan Zhan SUNYSB April 20th, 2010 #12;Outline · Introduction ­ Mechanism of Jet Breakup & Atomization ­ Dynamic Problems in Hg Target Flow · Mathematical Model for Hg Flow ­ Parameters ­ Incompressible Flow (No MHD) ­ Incompressible Flow (MHD) ­ Proton Beam Energy Conversion

  11. Data Flow Analysis Frameworks for Concurrent Programs

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Data Flow Analysis Frameworks for Concurrent Programs 1 Matthew B. Dwyer Department of Computer Science University of Massachusetts, Amherst Abstract Data flow analysis is a well studied family of static program analyses. A rich theoretical basis for data flow analysis has been developed. Central

  12. Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

    E-Print Network [OSTI]

    Marchese, Francis

    Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

  13. Tidal networks 3. Landscape-forming discharges and studies

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    Tidal networks 3. Landscape-forming discharges and studies in empirical geomorphic relationships peak ebb and flood discharges throughout a tidal network and use this model to investigate scaling flows are driven by spring (astronomical) tidal fluctuations (rather than precipitation- induced runoff

  14. TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND

    E-Print Network [OSTI]

    Fabrizio, Mary C.

    Chapter 14 TIDAL FRESHWATER WETLANDS OF THE MID-ATLANTIC AND SOUTHEASTERN UNITED STATES James E Jensen& Aat Barendregt 7. Animal communities in North American tidal fresh- water wetlands Christopher W Struyf, Tom Maris, Tom Cox & Patrick Meire 12. Carbon flows, nutrient cycling, and food webs in tidal

  15. Wind and tidal response of a semi-enclosed bay, Bahía Concepción, Baja California

    E-Print Network [OSTI]

    Ponte, Aurélien L. S.

    2009-01-01

    J. H. , 1973: Tidal patterns and energy balance in the GulfTable 4.1). Because the tidal energy is similar between boththe mouth. Some energy is captured by the tidal analysis at

  16. Infrastructure Analysis Tools: A Focus on Cash Flow Analysis (Presentation)

    SciTech Connect (OSTI)

    Melaina, M.; Penev, M.

    2012-09-01

    NREL has developed and maintains a variety of infrastructure analysis models for the U.S. Department of Energy. Business case analysis has recently been added to this tool set. This presentation focuses on cash flow analysis. Cash flows depend upon infrastructure costs, optimized spatially and temporally, and assumptions about financing and revenue. NREL has incorporated detailed metrics on financing and incentives into the models. Next steps in modeling include continuing to collect feedback on regional/local infrastructure development activities and 'roadmap' dynamics, and incorporating consumer preference assumptions on infrastructure to provide direct feedback between vehicles and station rollout.

  17. Flow-Through vs Flow-Over: Analysis of Transport and Binding in Nanohole Array Plasmonic

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    Flow-Through vs Flow-Over: Analysis of Transport and Binding in Nanohole Array Plasmonic Biosensors of flow-through nanohole sensing, as compared to the established flow-over format, through scaling and analytical response. The additional benefit offered by flow- through operation is, however, a complex

  18. Under consideration for publication in J. Fluid Mech. 1 Reflecting tidal wave beams and local

    E-Print Network [OSTI]

    were generated locally by a propagating beam of internal tidal energy which had originatedUnder consideration for publication in J. Fluid Mech. 1 Reflecting tidal wave beams and local generation mecha- nism: tidal flow over steep topography forces a propagating beam of internal tidal wave

  19. Static Information Flow Analysis for Java Department of Computer Science

    E-Print Network [OSTI]

    Bystroff, Chris

    Static Information Flow Analysis for Java Yin Liu Department of Computer Science Rensselaer their usage in software practice. This paper proposes run-time information flow models, and new static in software practice. We propose a new static information flow analysis towards this goal. This analysis

  20. Scenario Analysis of Pedestrian Flow in Public Amir Sohrab Sahaleh

    E-Print Network [OSTI]

    Bierlaire, Michel

    Scenario Analysis of Pedestrian Flow in Public Spaces Amir Sohrab Sahaleh Michel Bierlaire Bilal Farooq Antonin Danalet Flurin Silvan Hänseler STRC 2012 May 2012 #12;Scenario Analysis of Pedestrian Flow in Public Spaces May 2012 Scenario Analysis of Pedestrian Flow in Public Spaces Amir Sohrab Sahaleh

  1. Tidal Energy Basics

    Broader source: Energy.gov [DOE]

    Some of the oldest ocean energy technologies use tidal power. For tidal differences to be harnessed into electricity, the difference between high and low tides must be more than 16 feet (or at least 5 meters). However, there are only about 40 sites on Earth with tidal ranges of this magnitude.

  2. A study of grout flow pattern analysis

    SciTech Connect (OSTI)

    Lee, S. Y. [Savannah River National Lab., Aiken, SC (United States); Hyun, S. [Mercer Univ., Macon, GA (United States)

    2013-01-10

    A new disposal unit, designated as Salt Disposal Unit no. 6 (SDU6), is being designed for support of site accelerated closure goals and salt nuclear waste projections identified in the new Liquid Waste System plan. The unit is cylindrical disposal vault of 380 ft diameter and 43 ft in height, and it has about 30 million gallons of capacity. Primary objective was to develop the computational model and to perform the evaluations for the flow patterns of grout material in SDU6 as function of elevation of grout discharge port, and slurry rheology. A Bingham plastic model was basically used to represent the grout flow behavior. A two-phase modeling approach was taken to achieve the objective. This approach assumes that the air-grout interface determines the shape of the accumulation mound. The results of this study were used to develop the design guidelines for the discharge ports of the Saltstone feed materials in the SDU6 facility. The focusing areas of the modeling study are to estimate the domain size of the grout materials radially spread on the facility floor under the baseline modeling conditions, to perform the sensitivity analysis with respect to the baseline design and operating conditions such as elevation of discharge port, discharge pipe diameter, and grout properties, and to determine the changes in grout density as it is related to grout drop height. An axi-symmetric two-phase modeling method was used for computational efficiency. Based on the nominal design and operating conditions, a transient computational approach was taken to compute flow fields mainly driven by pumping inertia and natural gravity. Detailed solution methodology and analysis results are discussed here.

  3. Recurrent flow analysis in spatiotemporally chaotic 2-dimensional Kolmogorov flow

    E-Print Network [OSTI]

    Dan Lucas; Rich Kerswell

    2015-04-01

    Motivated by recent success in the dynamical systems approach to transitional flow, we study the efficiency and effectiveness of extracting simple invariant sets (recurrent flows) directly from chaotic/turbulent flows and the potential of these sets for providing predictions of certain statistics of the flow. Two-dimensional Kolmogorov flow (the 2D Navier-Stokes equations with a sinusoidal body force) is studied both over a square [0, 2{\\pi}]2 torus and a rectangular torus extended in the forcing direction. In the former case, an order of magnitude more recurrent flows are found than previously (Chandler & Kerswell 2013) and shown to give improved predictions for the dissipation and energy pdfs of the chaos via periodic orbit theory. Over the extended torus at low forcing amplitudes, some extracted states mimick the statistics of the spatially-localised chaos present surprisingly well recalling the striking finding of Kawahara & Kida (2001) in low-Reynolds-number plane Couette flow. At higher forcing amplitudes, however, success is limited highlighting the increased dimensionality of the chaos and the need for larger data sets. Algorithmic developments to improve the extraction procedure are discussed.

  4. Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...

    Open Energy Info (EERE)

    Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of Tracer-Determined Residence Time Distributions Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  5. THIN-FILM FLOWS WITH WALL SLIP: AN ASYMPTOTIC ANALYSIS OF HIGHER ORDER GLACIER FLOW MODELS

    E-Print Network [OSTI]

    Fournier, John J.F.

    THIN-FILM FLOWS WITH WALL SLIP: AN ASYMPTOTIC ANALYSIS OF HIGHER ORDER GLACIER FLOW MODELS, Cambridge, CB3 0ET, UK) [Received 6 January 2009. Revise 6 November 2009] Summary Free-surface thin film of the flow. Conversely, membrane or `free film' models are appropriate in situations where there is rapid

  6. Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal...

    Open Energy Info (EERE)

    Page Edit History Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgw...

  7. CFD analysis of laminar oscillating flows

    SciTech Connect (OSTI)

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

    2001-01-01

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

  8. Gradual Variation Analysis for Groundwater Flow

    E-Print Network [OSTI]

    Chen, Li

    2010-01-01

    Groundwater flow in Washington DC greatly influences the surface water quality in urban areas. The current methods of flow estimation, based on Darcy's Law and the groundwater flow equation, can be described by the diffusion equation (the transient flow) and the Laplace equation (the steady-state flow). The Laplace equation is a simplification of the diffusion equation under the condition that the aquifer has a recharging boundary. The practical way of calculation is to use numerical methods to solve these equations. The most popular system is called MODFLOW, which was developed by USGS. MODFLOW is based on the finite-difference method in rectangular Cartesian coordinates. MODFLOW can be viewed as a "quasi 3D" simulation since it only deals with the vertical average (no z-direction derivative). Flow calculations between the 2D horizontal layers use the concept of leakage. In this project, we have established a mathematical model based on gradually varied functions for groundwater data volume reconstruction. T...

  9. Multiphase Flow Analysis in Hydra-TH

    SciTech Connect (OSTI)

    Christon, Mark A. [Los Alamos National Laboratory; Bakosi, Jozsef [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Idaho National Laboratory

    2012-06-20

    This talk presents an overview of the multiphase flow efforts with Hydra-TH. The presentation begins with a definition of the requirements and design principles for multiphase flow relevant to CASL-centric problems. A brief survey of existing codes and their solution algorithms is presented before turning the model formulation selected for Hydra-TH. The issues of hyperbolicity and wellposedness are outlined, and a three candidate solution algorithms are discussed. The development status of Hydra-TH for multiphase flow is then presented with a brief summary and discussion of future directions for this work.

  10. University of Alberta Expression Data Flow Graph: Precise Flow-Sensitive Pointer Analysis for C Programs

    E-Print Network [OSTI]

    Amaral, José Nelson

    University of Alberta Expression Data Flow Graph: Precise Flow-Sensitive Pointer Analysis for C Thiessen Fall 2011 Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other

  11. POWER FLOW ANALYSIS OF ELECTROSTRICTIVE ACTUATORS DRIVEN BYSWITCHMODE AMPLIFIERS

    E-Print Network [OSTI]

    Lindner, Douglas K.

    of that energy. We adopt this view in this paper. The analysis in this paper is motivated by the smart skin being Consider the flow of energy through this smart skin. Electrical energy is supplied to the smart skin from energy into mechanical energy. This mechanical energy then flows from the smart skin into the surrounding

  12. REAL TIME FEATURE EXTRACTION FOR THE ANALYSIS OF TURBULENT FLOWS

    E-Print Network [OSTI]

    Interrante, Victoria

    great unsolved problem in classical physics, and all efforts to develop models to predict turbulent techniques, terabyte scale data sets are being generated, and hence stor- age as well as analysis include flow over aircraft, spacecraft, and other transport vehicles, flow inside of engines and power

  13. FULLYDISCRETE FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY

    E-Print Network [OSTI]

    Ewing, Richard E.

    FULLY­DISCRETE FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY Zhangxin Chen element method for a nonlinear differential system for describing an air­water system in groundwater experiments using the present approach for modeling groundwater flow in porous media are reported. Key words

  14. Fair Internet traffic integration: network flow models and analysis

    E-Print Network [OSTI]

    Kelly, Frank

    Fair Internet traffic integration: network flow models and analysis Peter Key, Laurent Massoulié the integration of two types of Internet traffic, elastic file transfers and streaming traffic. Previous studies have concentrated on just one type of traffic, such as the flow level models of Internet congestion

  15. Dynamical modeling of tidal streams

    SciTech Connect (OSTI)

    Bovy, Jo, E-mail: bovy@ias.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its 'track') in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of 'orphan' streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  16. Tidal Forces in Naked Singularity Backgrounds

    E-Print Network [OSTI]

    Goel, Akash; Roy, Pratim; Sarkar, Tapobrata

    2015-01-01

    The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is generically exemplified by the Roche limit, which predicts the distance within which a celestial object disintegrates due to the tidal effects of a second more massive object. In this paper, using Fermi normal coordinates, we numerically compute the Roche limit for a class of non-rotating naked singularity backgrounds, and compare them with known results for Schwarzschild black holes. Our analysis indicates that there might be substantially large deviations in the magnitudes of tidal forces in naked singularity backgrounds, compared to the black hole cases. If observationally established, these can prove to be an effective indicator of the nature of the singularity at a galactic centre.

  17. Gradient Flow Analysis on MILC HISQ Ensembles

    E-Print Network [OSTI]

    A. Bazavov; C. Bernard; N. Brown; C. DeTar; J. Foley; Steven Gottlieb; U. M. Heller; J. E. Hetrick; J. Komijani; J. Laiho; L. Levkova; M. Oktay; R. L. Sugar; D. Toussaint; R. S. Van de Water; R. Zhou

    2014-11-14

    We report on a preliminary scale determination with gradient-flow techniques on the $N_f = 2 + 1 + 1$ HISQ ensembles generated by the MILC collaboration. The ensembles include four lattice spacings, ranging from 0.15 to 0.06 fm, and both physical and unphysical values of the quark masses. The scales $\\sqrt{t_0}/a$ and $w_0/a$ are computed using Symanzik flow and the cloverleaf definition of $\\langle E \\rangle$ on each ensemble. Then both scales and the meson masses $aM_\\pi$ and $aM_K$ are adjusted for mistunings in the charm mass. Using a combination of continuum chiral perturbation theory and a Taylor series ansatz in the lattice spacing, the results are simultaneously extrapolated to the continuum and interpolated to physical quark masses. Our preliminary results are $\\sqrt{t_0} = 0.1422(7)$fm and $w_0 = 0.1732(10)$fm. We also find the continuum mass-dependence of $w_0$.

  18. Ice shelf-ocean interactions in a general circulation model : melt-rate modulation due to mean flow and tidal currents

    E-Print Network [OSTI]

    Dansereau, Véronique

    2012-01-01

    Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...

  19. Analysis of the velocity field of granular hopper flow

    E-Print Network [OSTI]

    F. G. R. Magalhães; A. P. F. Atman; J. G. Moreira; H. J. Herrmann

    2015-07-22

    We report the analysis of radial characteristics of the flow of granular material through a conical hopper. The discharge is simulated for various orifice sizes and hopper opening angles. Velocity profiles are measured along two radial lines from the hopper cone vertex: along the main axis of the cone and along its wall. An approximate power law dependence on the distance from the orifice is observed for both profiles, although differences between them can be noted. In order to quantify these differences, we propose a Local Mass Flow index that is a promising tool in the direction of a more reliable classification of the flow regimes in hoppers.

  20. Sudden increase in tidal response linked to calving and acceleration at a large Greenland outlet glacier

    E-Print Network [OSTI]

    de Juan, J.; Elosegui, P.; Nettles, M.; Larsen, T. B.; Davis, J. L.; Hamilton, Gordon S.; Stearns, Leigh; Anderson, M. L.; Ekstrom, G.; Ahlstrom, A. P.; Stenseng, L.; Khan, S. A.; Forsberg, R.

    2010-06-23

    [1] Large calving events at Greenland's largest outlet glaciers are associated with glacial earthquakes and near-instantaneous increases in glacier flow speed. At some glaciers and ice streams, flow is also modulated in a regular way by ocean tidal...

  1. Flow Imaging Using MRI: Quantification and Analysis 

    E-Print Network [OSTI]

    Jiraraksopakun, Yuttapong

    2010-07-14

    ) orthogonal one-dimensional displacement from all tag detected points [51]. Most of these motion analyses has been developed extensively to visualize or to assess cardiac motion. In analysis of heart motion, the myocardial contours at left ventricle (LV... and to automatically track both in-plane and through-plane displacements in three dimensions from a single image plane using a modified SF-CSPAMM [88]. Based on thin slice thickness and phase invariance conditions, the method (zHARP) can directly track the three-dimensional...

  2. Analysis of anisotropic flow with Lee-Yang zeroes

    E-Print Network [OSTI]

    R. S. Bhalerao; N. Borghini; J. -Y. Ollitrault

    2003-10-03

    We present a new method to extract anisotropic flow in heavy ion collisions from the genuine correlation among a large number of particles. Anisotropic flow is obtained from the zeroes in the complex plane of a generating function of azimuthal correlations, in close analogy with the theory of phase transitions by Lee and Yang. Flow is first estimated globally, i.e., averaged over the phase space covered by the detector, and then differentially, as a function of transverse momentum and rapidity for identified particles. The corresponding estimates are less biased by nonflow correlations than with any other method. The practical implementation of the method is rather straightforward. Furthermore, it automatically takes into account most corrections due to azimuthal anisotropies in the detector acceptance. The main limitation of the method is statistical errors, which can be significantly larger than with the ``standard'' method of flow analysis if the flow and/or the event multiplicities are too small. In practice, we expect this to be the most accurate method to analyze directed and elliptic flow in fixed-target heavy-ion collisions between 100 MeV and 10 GeV per nucleon (at the Darmstadt SIS synchrotron and the Brookhaven Alternating Gradient Synchrotron), and elliptic flow at ultrarelativistic energies (at the Brookhaven Relativistic Heavy Ion Collider, and the forthcoming Large Hadron Collider at CERN).

  3. UNIVERSITY OF CALIFORNIA, Ion Flow Measurements and Plasma Current Analysis

    E-Print Network [OSTI]

    Heidbrink, William W.

    UNIVERSITY OF CALIFORNIA, IRVINE Ion Flow Measurements and Plasma Current Analysis in the Irvine OF THE DISSERTATION xvii 1 Introduction 1 2 Field Reversed Configurations 4 2.1 FRC Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.3 FRC Instabilities . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.1.4 FRC Formation

  4. IDS120h GEOMETRY WITH SHIELDING VESSELS ENERGY FLOW ANALYSIS

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h GEOMETRY WITH SHIELDING VESSELS ENERGY FLOW ANALYSIS SHIELDING MATERIAL: 60% W + 40% He vs SHIELDING Nicholas Souchlas, PBL (10/18/2011) 1 #12;IDS120h with shielding vessels. # Different cases ENERGY CUTOFF >SHIELDING: 60% W + 40% He , 80% W + 20% He, 88% W + 12% He ( WITH W VESSELS) >4 MW proton

  5. Power flow analysis for amplifier design and energy harvesting

    E-Print Network [OSTI]

    Lindner, Douglas K.

    . In order to improve the efficiency of an active isolation system we analyze different feedback control energy on a active vibration isolation system it is important to understand the influence of the existingPower flow analysis for amplifier design and energy harvesting Nikola Vujica, Donald J. Leoa

  6. The Analysis of a Coating Flow with Evaporation

    E-Print Network [OSTI]

    The Analysis of a Coating Flow with Evaporation Jurgen Socolowsky Abstract. This work is concerned with a plane steady-state coating ow problem including evaporation e ects. The motion is governed by a free-Stokes equations. Key Words. Coating ow, evaporation, free boundary problems, Navier- Stokes equations, Stefan

  7. THE ANALYSIS OF COATING FLOWS NEAR THE CONTACT LINE

    E-Print Network [OSTI]

    THE ANALYSIS OF COATING FLOWS NEAR THE CONTACT LINE AVNER FRIEDMAN* and JUAN J.L. VELAZQUEZ** 0. Introduction. The term \\coating ows" refers to any viscous ow which is used to coat surfaces. Such ows are used for coating photographic lms, magnetic tapes, optical devices and, of course, for painting surfaces. Various

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

    SciTech Connect (OSTI)

    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.

  9. Assessment of Strike of Adult Killer Whales by an OpenHydro Tidal Turbine Blade

    SciTech Connect (OSTI)

    Carlson, Thomas J.; Elster, Jennifer L.; Jones, Mark E.; Watson, Bruce E.; Copping, Andrea E.; Watkins, Michael L.; Jepsen, Richard A.; Metzinger, Kurt

    2012-02-01

    Report to DOE on an analysis to determine the effects of a potential impact to an endangered whale from tidal turbines proposed for deployment in Puget Sound.

  10. Metagenomic analysis of planktonic microbial consortia from a non-tidal urban-impacted segment of James River

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

    Brown, Bonnie L.; LePrell, Rebecca V.; Franklin, Rima B.; Rivera, Maria C.; Cabral, Francine M.; Eaves, Hugh L.; Gardiakos, Vicki; Keegan, Kevin P.; King, Timothy L.

    2015-09-19

    Knowledge of the diversity and ecological function of the microbial consortia of James River in Virginia, USA, is essential to developing a more complete understanding of the ecology of this model river system. Metagenomic analysis of James River's planktonic microbial community was performed for the first time using an unamplified genomic library and a 16S rDNA amplicon library prepared and sequenced by Ion PGM and MiSeq, respectively. From the 0.46-Gb WGS library (GenBank:SRR1146621; MG-RAST:4532156.3), 4 x 106 reads revealed >3 x 106 genes, 240 families of prokaryotes, and 155 families of eukaryotes. From the 0.68-Gb 16S library (GenBank:SRR2124995; MG-RAST:4631271.3; EMB:2184),more »4 x 106 reads revealed 259 families of eubacteria. Results of the WGS and 16S analyses were highly consistent and indicated that more than half of the bacterial sequences were Proteobacteria, predominantly Comamonadaceae. The most numerous genera in this group were Acidovorax (including iron oxidizers, nitrotolulene degraders, and plant pathogens), which accounted for 10 % of assigned bacterial reads. Polaromonas were another 6 % of all bacterial reads, with many assignments to groups capable of degrading polycyclic aromatic hydrocarbons. Albidiferax (iron reducers) and Variovorax (biodegraders of a variety of natural biogenic compounds as well as anthropogenic contaminants such as polycyclic aromatic hydrocarbons and endocrine disruptors) each accounted for an additional 3% of bacterial reads. Comparison of these data to other publically-available aquatic metagenomes revealed that this stretch of James River is highly similar to the upper Mississippi River, and that these river systems are more similar to aquaculture and sludge ecosystems than they are to lakes or to a pristine section of the upper Amazon River. Altogether, these analyses exposed previously unknown aspects of microbial biodiversity, documented the ecological responses of microbes to urban effects, and revealed the noteworthy presence of 22 human-pathogenic bacterial genera (e.g., Enterobacteriaceae, pathogenic Pseudomonadaceae, and ‘Vibrionales') and 6 pathogenic eukaryotic genera (e.g., Trypanosomatidae and Vahlkampfiidae). This information about pathogen diversity may be used to promote human epidemiological studies, enhance existing water quality monitoring efforts, and increase awareness of the possible health risks associated with recreational use of James River.« less

  11. Metagenomic analysis of planktonic microbial consortia from a non-tidal urban-impacted segment of James River

    SciTech Connect (OSTI)

    Brown, Bonnie L.; LePrell, Rebecca V.; Franklin, Rima B.; Rivera, Maria C.; Cabral, Francine M.; Eaves, Hugh L.; Gardiakos, Vicki; Keegan, Kevin P.; King, Timothy L.

    2015-09-19

    Knowledge of the diversity and ecological function of the microbial consortia of James River in Virginia, USA, is essential to developing a more complete understanding of the ecology of this model river system. Metagenomic analysis of James River's planktonic microbial community was performed for the first time using an unamplified genomic library and a 16S rDNA amplicon library prepared and sequenced by Ion PGM and MiSeq, respectively. From the 0.46-Gb WGS library (GenBank:SRR1146621; MG-RAST:4532156.3), 4 x 106 reads revealed >3 x 106 genes, 240 families of prokaryotes, and 155 families of eukaryotes. From the 0.68-Gb 16S library (GenBank:SRR2124995; MG-RAST:4631271.3; EMB:2184), 4 x 106 reads revealed 259 families of eubacteria. Results of the WGS and 16S analyses were highly consistent and indicated that more than half of the bacterial sequences were Proteobacteria, predominantly Comamonadaceae. The most numerous genera in this group were Acidovorax (including iron oxidizers, nitrotolulene degraders, and plant pathogens), which accounted for 10 % of assigned bacterial reads. Polaromonas were another 6 % of all bacterial reads, with many assignments to groups capable of degrading polycyclic aromatic hydrocarbons. Albidiferax (iron reducers) and Variovorax (biodegraders of a variety of natural biogenic compounds as well as anthropogenic contaminants such as polycyclic aromatic hydrocarbons and endocrine disruptors) each accounted for an additional 3% of bacterial reads. Comparison of these data to other publically-available aquatic metagenomes revealed that this stretch of James River is highly similar to the upper Mississippi River, and that these river systems are more similar to aquaculture and sludge ecosystems than they are to lakes or to a pristine section of the upper Amazon River. Altogether, these analyses exposed previously unknown aspects of microbial biodiversity, documented the ecological responses of microbes to urban effects, and revealed the noteworthy presence of 22 human-pathogenic bacterial genera (e.g., Enterobacteriaceae, pathogenic Pseudomonadaceae, and ‘Vibrionales') and 6 pathogenic eukaryotic genera (e.g., Trypanosomatidae and Vahlkampfiidae). This information about pathogen diversity may be used to promote human epidemiological studies, enhance existing water quality monitoring efforts, and increase awareness of the possible health risks associated with recreational use of James River.

  12. Laboratory studies of eddy structures and exchange processes through tidal inlets 

    E-Print Network [OSTI]

    Nicolau del Roure, Francisco

    2009-06-02

    , Germany, which has the capability to generate a sinusoidal flow that simulates a series of tidal cycles. A set of idealized inlets were arranged in the tank, and by varying the tidal period and the maximum velocity, three different types of life...

  13. Cross-shore suspended sediment transport under tidal currents Andrew J. Hogg1

    E-Print Network [OSTI]

    Hogg, Andrew

    Cross-shore suspended sediment transport under tidal currents Andrew J. Hogg1 and David Pritchard2-mail: david@bpi.cam.ac.uk Abstract The transport of sediment over an intertidal mudflat by a cross-shore tidal-layer approximation. It is found that the sediment transport comprises advection with the mean flow, deposition

  14. Aalborg Universitet Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed., & Guerrero, J. M. (2014). Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed.aau.dk on: juli 04, 2015 #12;Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed

  15. Aalborg Universitet Power flow analysis for DC voltage droop controlled DC microgrids

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Power flow analysis for DC voltage droop controlled DC microgrids Li, Chendan). Power flow analysis for DC voltage droop controlled DC microgrids. In Proceedings of the 11th.aau.dk on: juli 07, 2015 #12;Power flow analysis for DC voltage droop controlled DC microgrids Chendan Li

  16. Cross-flow versus counter-current flow packed-bed scrubbers: a mathematical analysis

    SciTech Connect (OSTI)

    Fthenakis, V.M.

    1996-02-01

    Little is known about the mass transfer properties of packing media exposed to a crossflow of gas and liquid, whereas there is abundant information related to counter-current scrubbers. This paper presents a theoretical analysis of mass transfer and hydrodynamics in cross- flow packed bed scrubbers and compares those with information available for counter current towers, so that the first can be evaluated and/or designed based on data derived for the second. Mathematical models of mass transfer in cross-flow and counter- current packed bed scrubbers are presented. From those, one can predict the removal effectiveness of a crossflow scrubber from the number of transfer units (NTU) calculated for a similar counterflow operation; alternatively, when the removal effectiveness in counterflow is known, one can predict the corresponding NTU in crossflow.

  17. How does vegetation affect sedimentation on tidal marshes? Investigating particle capture and hydrodynamic controls

    E-Print Network [OSTI]

    Mudd, Simon Marius

    How does vegetation affect sedimentation on tidal marshes? Investigating particle capture stems, or enhanced settling due to a reduction in turbulent kinetic energy within flows through kinetic energy in the fertilized canopy. Our newly developed models of biologically mediated sedimentation

  18. Validation Analysis of the Shoal Groundwater Flow and Transport Model

    SciTech Connect (OSTI)

    A. Hassan; J. Chapman

    2008-11-01

    Environmental restoration at the Shoal underground nuclear test is following a process prescribed by a Federal Facility Agreement and Consent Order (FFACO) between the U.S. Department of Energy, the U.S. Department of Defense, and the State of Nevada. Characterization of the site included two stages of well drilling and testing in 1996 and 1999, and development and revision of numerical models of groundwater flow and radionuclide transport. Agreement on a contaminant boundary for the site and a corrective action plan was reached in 2006. Later that same year, three wells were installed for the purposes of model validation and site monitoring. The FFACO prescribes a five-year proof-of-concept period for demonstrating that the site groundwater model is capable of producing meaningful results with an acceptable level of uncertainty. The corrective action plan specifies a rigorous seven step validation process. The accepted groundwater model is evaluated using that process in light of the newly acquired data. The conceptual model of ground water flow for the Project Shoal Area considers groundwater flow through the fractured granite aquifer comprising the Sand Springs Range. Water enters the system by the infiltration of precipitation directly on the surface of the mountain range. Groundwater leaves the granite aquifer by flowing into alluvial deposits in the adjacent basins of Fourmile Flat and Fairview Valley. A groundwater divide is interpreted as coinciding with the western portion of the Sand Springs Range, west of the underground nuclear test, preventing flow from the test into Fourmile Flat. A very low conductivity shear zone east of the nuclear test roughly parallels the divide. The presence of these lateral boundaries, coupled with a regional discharge area to the northeast, is interpreted in the model as causing groundwater from the site to flow in a northeastward direction into Fairview Valley. Steady-state flow conditions are assumed given the absence of groundwater withdrawal activities in the area. The conceptual and numerical models were developed based upon regional hydrogeologic investigations conducted in the 1960s, site characterization investigations (including ten wells and various geophysical and geologic studies) at Shoal itself prior to and immediately after the test, and two site characterization campaigns in the 1990s for environmental restoration purposes (including eight wells and a year-long tracer test). The new wells are denoted MV-1, MV-2, and MV-3, and are located to the northnortheast of the nuclear test. The groundwater model was generally lacking data in the north-northeastern area; only HC-1 and the abandoned PM-2 wells existed in this area. The wells provide data on fracture orientation and frequency, water levels, hydraulic conductivity, and water chemistry for comparison with the groundwater model. A total of 12 real-number validation targets were available for the validation analysis, including five values of hydraulic head, three hydraulic conductivity measurements, three hydraulic gradient values, and one angle value for the lateral gradient in radians. In addition, the fracture dip and orientation data provide comparisons to the distributions used in the model and radiochemistry is available for comparison to model output. Goodness-of-fit analysis indicates that some of the model realizations correspond well with the newly acquired conductivity, head, and gradient data, while others do not. Other tests indicated that additional model realizations may be needed to test if the model input distributions need refinement to improve model performance. This approach (generating additional realizations) was not followed because it was realized that there was a temporal component to the data disconnect: the new head measurements are on the high side of the model distributions, but the heads at the original calibration locations themselves have also increased over time. This indicates that the steady-state assumption of the groundwater model is in error. To test the robustness of the model d

  19. 1992 Columbia River Salmon Flow Measures Options Analysis/EIS.

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FSWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and one private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described.

  20. Temperature and Tidal Dynamics in a Branching Estuarine System

    E-Print Network [OSTI]

    Wagner, Richard Wayne

    2012-01-01

    distribution of tidal energy. When specific locations ordissipation which may alter tidal energy in other parts ofAdditionally, changes to tidal energy reflection within a

  1. High throughput analysis of samples in flowing liquid

    DOE Patents [OSTI]

    Ambrose, W. Patrick (Los Alamos, NM); Grace, W. Kevin (Los Alamos, NM); Goodwin, Peter M. (Los Alamos, NM); Jett, James H. (Los Alamos, NM); Orden, Alan Van (Fort Collins, CO); Keller, Richard A. (White Rock, NM)

    2001-01-01

    Apparatus and method enable imaging multiple fluorescent sample particles in a single flow channel. A flow channel defines a flow direction for samples in a flow stream and has a viewing plane perpendicular to the flow direction. A laser beam is formed as a ribbon having a width effective to cover the viewing plane. Imaging optics are arranged to view the viewing plane to form an image of the fluorescent sample particles in the flow stream, and a camera records the image formed by the imaging optics.

  2. Microsoft Word - RM1_Tidal Turbine_UW Tidal Resource-Abstract...

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

    turbine operating in a narrow, tidal channel. The site is a generalized version of Tacoma Narrows, Puget Sound, Washington. The resource is a mixed, mainly semidiurnal tidal...

  3. STABILITY ANALYSIS FOR BUOYANCY-OPPOSED FLOWS IN POLOIDAL DUCTS OF THE DCLL BLANKET

    E-Print Network [OSTI]

    Abdou, Mohamed

    STABILITY ANALYSIS FOR BUOYANCY-OPPOSED FLOWS IN POLOIDAL DUCTS OF THE DCLL BLANKET N. Vetcha, S, the most of heat deposition and tritium breeding occur in the poloidal ducts facing the plasma (front ducts flows in the long poloidal ducts are comparable with or can even dominate over forced flows, thus

  4. Stochastic Formulation for Uncertainty Analysis of Two-Phase Flow in

    E-Print Network [OSTI]

    Zhang, Dongxiao

    Stochastic Formulation for Uncertainty Analysis of Two-Phase Flow in Heterogeneous Reservoirs in flow performance predictions due to uncertainty in the reservoir description. We solve moment equations. Accurate modeling of the physics that govern complex multi- phase reservoir flows requires a detailed

  5. Analysis of Thermal Dispersion in an Array of Parallel Plates with Fully-Developed Laminar Flow

    E-Print Network [OSTI]

    Fleck, Norman A.

    basic heat transfer problems are addressed, each for steady fully-developed laminar fluid flow: (a1 Analysis of Thermal Dispersion in an Array of Parallel Plates with Fully-Developed Laminar Flow dispersion, parallel plate array, fully-developed laminar flow, Peclet number #12;2 Notation a molecular

  6. Flow rate analysis of a surface tension driven passive micropump{{ Erwin Berthiera

    E-Print Network [OSTI]

    Beebe, David J.

    , causing fluid flow. The behavior of the input drop occurs in two characteristic phases. An analytical value of Re = rU0L0/g # 1, meaning that the flow is very laminar, allowing the use of the Washburn lawFlow rate analysis of a surface tension driven passive micropump{{ Erwin Berthiera and David J

  7. Iterative Security Risk Analysis for Network Flows Based on Provenance and Interdependency

    E-Print Network [OSTI]

    New South Wales, University of

    Iterative Security Risk Analysis for Network Flows Based on Provenance and Interdependency Mohsen high risk network flows and hosts in a high throughput network is a challenging task of network malicious and high risk network activities within a huge number of monitored network flows. To address

  8. Vibrio litoralis sp. nov., isolated from a Yellow Sea tidal flat in Korea

    E-Print Network [OSTI]

    Bae, Jin-Woo

    Vibrio litoralis sp. nov., isolated from a Yellow Sea tidal flat in Korea Young-Do Nam,1,2 Ho-negative, facultatively anaerobic bacterial strains, MANO22DT and MANO22P, were isolated from a tidal flat area of Dae and energy sources. A phylogenetic analysis based on 16S rRNA gene sequences revealed that the strains belong

  9. Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal

    E-Print Network [OSTI]

    Bukaveckas, Paul A.

    that cause the formation of a chlorophyll maximum within the tidal freshwater James River. Phyto- plankton in their dominant mode of hydrodynamics, tidal freshwaters share a number of features in common with rivers of the saline estuary. Their hydrodynamics are dominated by bi- directional flow but are subject to considerable

  10. Anisotropic flow

    E-Print Network [OSTI]

    S. A. Voloshin

    2002-11-20

    Recent experimental results on directed and elliptic flow, theoretical developments, and new techniques for anisotropic flow analysis are reviewed.

  11. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

    SciTech Connect (OSTI)

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.

  12. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

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

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Dopplermore »Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.« less

  13. A MultiPhase Power Flow Model for Grid Analysis A. P. Sakis Meliopoulos

    E-Print Network [OSTI]

    A MultiPhase Power Flow Model for µµµµGrid Analysis A. P. Sakis Meliopoulos School of Electrical power system with distributed energy sources forming a microgrid (µGrid). The µGrid is a radial multiphase power flow analysis method that provides exact solution to the operation of the µGrid under steady

  14. Tidal evolution of close binary asteroid systems

    E-Print Network [OSTI]

    Taylor, PA; Margot, JL

    2010-01-01

    a positive fractional power of the tidal frequency (at leasttidal bulges of the components as these will depend on the square (or higher powers)power, natural deviations from a spherical shape may exceed the amplitude of the tidal

  15. Palomar 5 and its Tidal Tails: A Search for New Members in the Tidal Stream

    E-Print Network [OSTI]

    Kuzma, Pete; Keller, Stefan; Maunder, Elizabeth

    2014-01-01

    In this paper we present the results of a search for members of the globular cluster Palomar 5 and its associated tidal tails. The analysis has been performed using intermediate and low resolution spectroscopy with the AAOmega spectrograph on the Anglo-Australian Telescope. Based on kinematics, line strength and photometric information, we identify 39 new red giant branch stars along $\\sim$20$^{\\circ}$ of the tails, a larger angular extent than has been previously studied. We also recover eight previously known tidal tail members. Within the cluster, we find seven new red giant and one blue horizontal branch members and confirm a further twelve known red giant members. In total, we provide velocity data for 67 stars in the cluster and the tidal tails. Using a maximum likelihood technique, we derive a radial velocity for Pal 5 of $-57.4 \\pm 0.3$ km s$^{-1}$ and a velocity dispersion of $1.2\\pm0.3$ km s$^{-1}$. We confirm and extend the linear velocity gradient along the tails of $1.0 \\pm 0.1$ km s$^{-1}$ deg$^...

  16. Flow Measurement with Tangential Paddlewheel Flow Meters: Analysis of Experimental Results and in-situ Diagnostics 

    E-Print Network [OSTI]

    Watt, J. B.; Haberl, J. S.

    1994-01-01

    or generate a totalized signal that can be recorded by data acquisition system. The accuracy of totalized flow and energy measurements is directly effected by the quality of thermal and flow measurement devices. In a closed-loop system a thermal energy meter... possible solution is to use a frequency to voltage converter between the magnetic paddlewheel flow meter and thermal energy meter to transform the sine wave to a square wave much like the signal generated by the non-magnetic-type meter (Doeblin 1990...

  17. Time series power flow analysis for distribution connected PV generation.

    SciTech Connect (OSTI)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J.; Smith, Jeff; Dugan, Roger

    2013-01-01

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating potential PV impacts.

  18. Uncertainty Analysis for a Virtual Flow Meter Using an Air-Handling Unit Chilled Water Valve

    SciTech Connect (OSTI)

    Song, Li; Wang, Gang; Brambley, Michael R.

    2013-04-28

    A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the probability of error in the measurements is significantly greater than for conventionally manufactured flow meters. In this paper, mathematical models are developed and used to conduct uncertainty analysis for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded anuncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty analysis and empirical comparison with the ultrasonic flow meter corroborate each other, and tend to validate the approach to computationally estimating uncertainty for virtual sensors introduced in this study.

  19. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Alexander, T; Alexander, Tal; Morris, Mark

    2003-01-01

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (m<10^8 Mo) black hole (MBH), whose atypically high luminosity (up to a significant fraction of their Eddington luminosity) is powered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effe...

  20. Squeezars: Tidally powered stars orbiting a massive black hole

    E-Print Network [OSTI]

    Tal Alexander; Mark Morris

    2003-05-05

    We propose that there exists a class of transient sources, "squeezars", which are stars caught in highly eccentric orbits around a massive (mpowered by tidal interactions with the MBH. Their existence follows from the presence of a mass sink, the MBH, in the galactic center, which drives a flow of stars into nearly radial orbits to replace those it has destroyed. We consider two limits for the stellar response to tidal heating: surface heating with radiative cooling ("hot squeezars") and bulk heating with adiabatic expansion ("cold squeezars"), and calculate the evolution of the squeezar orbit, size, luminosity and effective temperature. The squeezar formation rate is only ~0.05 that of tidal disruption flares, but squeezar lifetimes are many orders of magnitude longer, and so future observations of squeezars in nearby galaxies can probe the tidal process that feeds MBHs and the effects of extreme tides on stars. The mean number of squeezars orbiting the Galactic MBH is estimated at 0.1-1.

  1. General relativistic tidal heating for Moller pseudotensor

    E-Print Network [OSTI]

    Lau Loi So

    2015-09-30

    Thorne elucidated that the relativistic tidal heating is the same as the Newtonian theory. Moreover, Thorne also claimed that the tidal heating is independent of how one localizes gravitational energy and is unambiguously given by a certain formula. Purdue and Favata calculated the tidal heating for different classical pseudotensors including Moller and obtained the results all matched with the Newtonian perspective. After re-examined this Moller pseudotensor, we find that there does not exist any tidal heating value. Thus we claim that the relativistic tidal heating is pseudotensor independent under the condition that if the peusdotensor is a Freud typed superpotential.

  2. General relativistic tidal heating for Moller pseudotensor

    E-Print Network [OSTI]

    So, Lau Loi

    2015-01-01

    Thorne elucidated that the relativistic tidal heating is the same as the Newtonian theory. Moreover, Thorne also claimed that the tidal heating is independent of how one localizes gravitational energy and is unambiguously given by a certain formula. Purdue and Favata calculated the tidal heating for different classical pseudotensors including Moller and obtained the results all matched with the Newtonian perspective. After re-examined this Moller pseudotensor, we find that there does not exist any tidal heating value. Thus we claim that the relativistic tidal heating is pseudotensor independent under the condition that if the peusdotensor is a Freud typed superpotential.

  3. Throughput-cost analysis of optical flow switching

    E-Print Network [OSTI]

    Chan, Vincent W. S.

    In this paper, we employ a cost model embodying major sources of capital expenditure (CapEx) to compare the throughput-cost tradeoff offered by optical flow switching to that of more traditional optical network architectures.

  4. Analysis of two- and three-dimensional flow separation

    E-Print Network [OSTI]

    Grunberg, Olivier, 1978-

    2004-01-01

    Prandtl (1904) showed that streamlines in a steady flow past a two-dimensional streamlined body separate from the boundary where the skin friction (or wall shear) vanishes and admits a negative gradient. Although commonly ...

  5. “Batch” Kinetics in Flow: Online IR Analysis and Continuous Control

    E-Print Network [OSTI]

    Moore, Jason S.

    Currently, kinetic data is either collected under steady-state conditions in flow or by generating time-series data in batch. Batch experiments are generally considered to be more suitable for the generation of kinetic ...

  6. Numerical analysis of vapor flow in a micro heat pipe 

    E-Print Network [OSTI]

    Liu, Xiaoqin

    1996-01-01

    The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two...

  7. Maine Tidal Power Initiative: Environmental Impact Protocols For Tidal Power

    SciTech Connect (OSTI)

    Peterson, Michael Leroy; Zydlewski, Gayle Barbin; Xue, Huijie; Johnson, Teresa R.

    2014-02-02

    The Maine Tidal Power Initiative (MTPI), an interdisciplinary group of engineers, biologists, oceanographers, and social scientists, has been conducting research to evaluate tidal energy resources and better understand the potential effects and impacts of marine hydro-kinetic (MHK) development on the environment and local community. Project efforts include: 1) resource assessment, 2) development of initial device design parameters using scale model tests, 3) baseline environmental studies and monitoring, and 4) human and community responses. This work included in-situ measurement of the environmental and social response to the pre-commercial Turbine Generator Unit (TGU®) developed by Ocean Renewable Power Company (ORPC) as well as considering the path forward for smaller community scale projects.

  8. Computerized tomographic analysis of fluid flow in fractured tuff

    SciTech Connect (OSTI)

    Felice, C.W.; Sharer, J.C.; Springer, E.P.

    1992-05-01

    The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.

  9. Computerized tomographic analysis of fluid flow in fractured tuff

    SciTech Connect (OSTI)

    Felice, C.W.; Sharer, J.C. ); Springer, E.P. )

    1992-01-01

    The purpose of this summary is to demonstrate the usefulness of X-ray computerized tomography to observe fluid flow down a fracture and rock matrix imbibition in a sample of Bandelier tuff. This was accomplished by using a tuff sample 152.4 mm long and 50.8 mm in diameter. A longitudinal fracture was created by cutting the core with a wire saw. The fractured piece was then coupled to its adjacent section to that the fracture was not expected. Water was injected into a dry sample at five flow rates and CT scanning performed at set intervals during the flow. Cross sectional images and longitudinal reconstructions were built and saturation profiles calculated for the sample at each time interval at each flow rate. The results showed that for the test conditions, the fracture was not a primary pathway of fluid flow down the sample. At a slow fluid injection rate into the dry sample, the fluid was imbibed into the rock uniformly down the length of the core. With increasing injection rates, the flow remained uniform over the core cross section through complete saturation.

  10. ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK

    E-Print Network [OSTI]

    Lawrence, Deborah

    i ORGANIC MATTER DISTRIBUTION AND TURNOVER ALONG A GRADIENT FROM FOREST TO TIDAL CREEK A Thesis. A nested plot design was used to harvest vegetation, obtain soil cores, and collect quantitative data... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .18 Qualitative Vegetation Analysis

  11. STABILITY ANALYSIS FOR THE HARTMANN FLOW WITH INTERFACIAL VETCHA Naveen , SMOLENTSEV Sergey, ABDOU Mohamed

    E-Print Network [OSTI]

    Abdou, Mohamed

    STABILITY ANALYSIS FOR THE HARTMANN FLOW WITH INTERFACIAL SLIP VETCHA Naveen , SMOLENTSEV Sergey of the Hartmann flow by modifying the Orr-Sommerfeld problem to account for the slip effect. A MATLAB code based compared to the thickness of the Hartmann layer. 1. Introduction Interfacial slip has recently been

  12. Analysis of passive scalar advection in parallel shear flows: Sorting of modes at intermediate time scales

    E-Print Network [OSTI]

    Camassa, Roberto

    Analysis of passive scalar advection in parallel shear flows: Sorting of modes at intermediate time; published online 4 November 2010 The time evolution of a passive scalar advected by parallel shear flows. INTRODUCTION The advection-diffusion of a passive scalar is a pivotal problem in mathematical physics

  13. Information-Flow Analysis of Android Applications in DroidSafe

    E-Print Network [OSTI]

    Rinard, Martin

    Information-Flow Analysis of Android Applications in DroidSafe Michael I. Gordon, Deokhwan Kim analysis tool that reports potential leaks of sensitive information in Android applications. DroidSafe combines a comprehensive, accurate, and precise model of the Android runtime with static analysis design

  14. Modeling of In-stream Tidal Energy Development and its Potential Effects in Tacoma Narrows, Washington, USA

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.; Geerlofs, Simon H.

    2014-10-01

    Understanding and providing proactive information on the potential for tidal energy projects to cause changes to the physical system and to key water quality constituents in tidal waters is a necessary and cost-effective means to avoid costly regulatory involvement and late stage surprises in the permitting process. This paper presents a modeling study for evaluating the tidal energy extraction and its potential impacts on the marine environment in a real world site - Tacoma Narrows of Puget Sound, Washington State, USA. An unstructured-grid coastal ocean model, fitted with a module that simulates tidal energy devices, was applied to simulate the tidal energy extracted by different turbine array configurations and the potential effects of the extraction at local and system-wide scales in Tacoma Narrows and South Puget Sound. Model results demonstrated the advantage of an unstructured-grid model for simulating the far-field effects of tidal energy extraction in a large model domain, as well as assessing the near-field effect using a fine grid resolution near the tidal turbines. The outcome shows that a realistic near-term deployment scenario extracts a very small fraction of the total tidal energy in the system and that system wide environmental effects are not likely; however, near-field effects on the flow field and bed shear stress in the area of tidal turbine farm are more likely. Model results also indicate that from a practical standpoint, hydrodynamic or water quality effects are not likely to be the limiting factor for development of large commercial-scale tidal farms. Results indicate that very high numbers of turbines are required to significantly alter the tidal system; limitations on marine space or other environmental concerns are likely to be reached before reaching these deployment levels. These findings show that important information obtained from numerical modeling can be used to inform regulatory and policy processes for tidal energy development.

  15. Analysis of operating data related to power and flow distribution in a PWR

    E-Print Network [OSTI]

    Herbin, Henry Christophe

    1974-01-01

    The analysis of the effects of the uncertainties associated with temperature and power measurements in the Connecticut Yankee Reactor leads to the evaluation of the uncertainty associated with the effective flow factor. ...

  16. IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF...

    Open Energy Info (EERE)

    IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings:...

  17. Well-test analysis of multi-phase flow from two layers communicating through the wellbore 

    E-Print Network [OSTI]

    Iakovlev, Serguei

    1999-01-01

    Conventional buildup analysis techniques are based on analytical solutions to the diffusivity equation that are subject to well-known assumptions. During actual well tests multi-phase flow in several layers with different ...

  18. Performance Analysis of an Annular Diffuser Under the Influence of a Gas Turbine Stage Exit Flow

    E-Print Network [OSTI]

    Blanco, Rafael Rodriguez

    2013-12-31

    In this investigation the performance of a gas turbine exhaust diffuser subject to the outlet flow conditions of a turbine stage is evaluated. Towards that goal, a fully three-dimensional computational analysis has been performed where several...

  19. Lagrangian analysis of fluid transport in empirical vortex ring flows Shawn C. Shadden

    E-Print Network [OSTI]

    Marsden, Jerrold

    Lagrangian analysis of fluid transport in empirical vortex ring flows Shawn C. Shadden Control and Dynamical Systems, California Institute of Technology, Pasadena, California 91125 John O. Dabiri Graduate Aeronautical Laboratories and Bioengineering, California Institute of Technology, Pasadena, California 91125

  20. Tidally-induced thermonuclear Supernovae

    E-Print Network [OSTI]

    S. Rosswog; E. Ramirez-Ruiz; W. R. Hix

    2008-11-13

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than $2\\times 10^5$ M$_\\odot$ swallow a typical 0.6 M$_\\odot$ dwarf before their tidal forces can overwhelm the star's self-gravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an X-ray flare close to the Eddington limit of $L_{\\rm Edd} \\simeq 10^{41} {\\rm erg/s} M_{\\rm bh}/1000 M$_\\odot$), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  1. Finite element analysis of conjugate heat transfer in axisymmetric pipe flows 

    E-Print Network [OSTI]

    Fithen, Robert Miller

    1987-01-01

    FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MA STER... OF S CI EN CE August 1987 Major Subject: Mechanical Engineering FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Approved ss to style and content by: N. K. Anand (Chairman of Committee...

  2. Two-phase stratified flow regime transition analysis for low gravity conditions 

    E-Print Network [OSTI]

    Miller, Kathryn M.

    1990-01-01

    TWO-PHASE STRATIFIED FLOW REGIME TRANSITION ANALYSIS FOR LOW GRAVITY CONDITIONS A Thesis by KATHRYN M. MILLER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1990 Major Subject: Nuclear Engineering TWO-PHASE STRATIFIED FLOW REGIME TRANSITION ANALYSIS FOR LOW GRAVITY CONDITIONS A Thesis KATHRYN M. MILLER Approved as to style and content by: Frederick R. Best (Chair...

  3. Transaction Based Power Flow Analysis For Transmission Utilization Allocation

    E-Print Network [OSTI]

    electricity market at the ex ante phase; (ii) MW generations are decided by bilateral contracts and other contributions of individual generators to loads and flows upon the so-called proportional sharing principle the electric power industry moves into an era of supply competition and consumer choice, the power system

  4. Thermal analysis and air flow modelling of electrical machines 

    E-Print Network [OSTI]

    Chong, Yew Chuan

    2015-06-29

    Thermal analysis is an important topic that can affect the electrical machine performance, reliability, lifetime and efficiency. In order to predict the electrical machine thermal performance accurately, thermal analysis ...

  5. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect (OSTI)

    Fuller, Jim; Lai Dong [Department of Astronomy, Cornell University, Ithaca, NY 14850 (United States)

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  6. First-post-Newtonian quadrupole tidal interactions in binary systems

    E-Print Network [OSTI]

    Justin Vines; Éanna É. Flanagan

    2014-10-09

    We consider tidal coupling in a binary stellar system to first-post-Newtonian order. We derive the orbital equations of motion for bodies with spins and mass quadrupole moments and show that they conserve the total linear momentum of the binary. We note that spin-orbit coupling must be included in a 1PN treatment of tidal interactions in order to maintain consistency (except in the special case of adiabatically induced quadrupoles); inclusion of 1PN quadrupolar tidal effects while omitting spin effects would lead to a failure of momentum conservation for generic evolution of the quadrupoles. We use momentum conservation to specialize our analysis to the system's center-of-mass-energy frame; we find the binary's relative equation of motion in this frame and also present a generalized Lagrangian from which it can be derived. We then specialize to the case in which the quadrupole moment is adiabatically induced by the tidal field (in which case it is consistent to ignore spin effects). We show how the adiabatic dynamics for the quadrupole can be incorporated into our action principle and present the simplified orbital equations of motion and conserved energy for the adiabatic case. These results are relevant to gravitational wave signals from inspiralling binary neutron stars.

  7. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    SciTech Connect (OSTI)

    P. Tucci

    2001-12-20

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M&O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment.

  8. Analysis of Developing Gas/liquid Two-Phase Flows

    SciTech Connect (OSTI)

    Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal; Donna Post Guillen; Matthias Beyer; Dirk Lucas

    2010-06-01

    The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made in simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.

  9. Acoustic Effects of Hydrokinetic Tidal Turbines

    SciTech Connect (OSTI)

    Polagye, Brian

    2011-11-01

    This presentation from the Water Peer Review highlights one of the program's marine and hyrokinetics environmental projects to determine the likely acoustic effects from a tidal energy device.

  10. Flow Injection Analysis in a Microfluidic Format Andrew M. Leach, Aaron R. Wheeler, and Richard N. Zare*

    E-Print Network [OSTI]

    Zare, Richard N.

    Flow Injection Analysis in a Microfluidic Format Andrew M. Leach, Aaron R. Wheeler, and Richard N should be addressed email: zare@stanford.edu #12;2 ABSTRACT A microfluidic flow injection analysis system the operation of a standard six-port, two-way valve used in conventional liquid chromatography and flow

  11. A Flow-Channel Analysis for the Mars Hopper

    SciTech Connect (OSTI)

    W. Spencer Cooley

    2013-02-01

    The Mars Hopper is an exploratory vehicle designed to fly on Mars using carbon dioxide from the Martian atmosphere as a rocket propellant. The propellent gasses are thermally heated while traversing a radioisotope ther- mal rocket (RTR) engine’s core. This core is comprised of a radioisotope surrounded by a heat capacitive material interspersed with tubes for the propellant to travel through. These tubes, or flow channels, can be manu- factured in various cross-sectional shapes such as a special four-point star or the traditional circle. Analytical heat transfer and computational fluid dynamics (CFD) anal- yses were performed using flow channels with either a circle or a star cross- sectional shape. The nominal total inlet pressure was specified at 2,805,000 Pa; and the outlet pressure was set to 2,785,000 Pa. The CO2 inlet tem- perature was 300 K; and the channel wall was 1200 K. The steady-state CFD simulations computed the smooth-walled star shape’s outlet temper- ature to be 959 K on the finest mesh. The smooth-walled circle’s outlet temperature was 902 K. A circle with a surface roughness specification at 0.01 mm gave 946 K and at 0.1 mm yielded 989 K. The The effects of a slightly varied inlet pressure were also examined. The analytical calculations were based on the mass flow rates computed in the CFD simulations and provided significantly higher outlet temperature results while displaying the same comparison trends. Research relating to the flow channel heat transfer studies was also done. Mathematical methods to geometrically match the cross-sectional areas of the circle and star, along with a square and equilateral triangle, were derived. A Wolfram Mathematica 8 module was programmed to analyze CFD results using Richardson Extrapolation and calculate the grid convergence index (GCI). A Mathematica notebook, also composed, computes and graphs the bulk mean temperature along a flow channel’s length while the user dynam- ically provides the input variables, allowing their effects on the temperature to be more easily observed.

  12. Experimental investigation and CFD analysis on cross flow in the core of PMR200

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

    Lee, Jeong -Hun; Yoon, Su -Jong; Cho, Hyoung -Kyu; Jae, Moosung; Park, Goon -Cherl

    2015-04-16

    The Prismatic Modular Reactor (PMR) is one of the major Very High Temperature Reactor (VHTR) concepts, which consists of hexagonal prismatic fuel blocks and reflector blocks made of nuclear gradegraphite. However, the shape of the graphite blocks could be easily changed by neutron damage duringthe reactor operation and the shape change can create gaps between the blocks inducing the bypass flow.In the VHTR core, two types of gaps, a vertical gap and a horizontal gap which are called bypass gap and cross gap, respectively, can be formed. The cross gap complicates the flow field in the reactor core by connectingmore »the coolant channel to the bypass gap and it could lead to a loss of effective coolant flow in the fuel blocks. Thus, a cross flow experimental facility was constructed to investigate the cross flow phenomena in the core of the VHTR and a series of experiments were carried out under varying flow rates and gap sizes. The results of the experiments were compared with CFD (Computational Fluid Dynamics) analysis results in order to verify its prediction capability for the cross flow phenomena. Fairly good agreement was seen between experimental results and CFD predictions and the local characteristics of the cross flow was discussed in detail. Based on the calculation results, pressure loss coefficient across the cross gap was evaluated, which is necessary for the thermo-fluid analysis of the VHTR core using a lumped parameter code.« less

  13. Spectral analysis of the efficiency of vertical mixing in the deep ocean due to interaction of tidal currents with a ridge running down a continental slope

    SciTech Connect (OSTI)

    Ibragimov, Ranis N.; Tartakovsky, Alexandre M.

    2014-10-29

    Efficiency of mixing, resulting from the reflection of an internal wave field imposed on the oscillatory background flow with a three-dimensional bottom topography, is investigated using a linear approximation. The radiating wave field is associated with the spectrum of the linear model, which consists of those mode numbers n and slope values ?, for which the solution represents the internal waves of frequencies ? = n?0 radiating upwrad of the topography, where ?0 is the fundamental frequency at which internal waves are generated at the topography. The effects of the bottom topography and the earth’s rotation on the spectrum is analyzed analytically and numerically in the vicinity of the critical slope, which is a slope with the same angle to the horizontal as the internal wave characteristic. In this notation, ? is latitude, f is the Coriolis parameter and N is the buoyancy frequency, which is assumed to be a constant, which corresponds to the uniform stratification.

  14. Fusion Engineering and Design 82 (2007) 22172225 Integrated thermo-fluid analysis towards helium flow

    E-Print Network [OSTI]

    Abdou, Mohamed

    2007-01-01

    Fusion Engineering and Design 82 (2007) 2217­2225 Integrated thermo-fluid analysis towards helium Engineering and Design 82 (2007) 2217­2225 This calls in for an extensive analysis of the various proposed flow path design for an ITER solid breeder blanket module A. Yinga,, M. Narulaa, R. Hunta, M. Abdoua, Y

  15. Computational Analysis of Material Flow During Friction Stir Welding of AA5059 Aluminum Alloys

    E-Print Network [OSTI]

    Grujicic, Mica

    Computational Analysis of Material Flow During Friction Stir Welding of AA5059 Aluminum Alloys M welding (FSW) process are investigated computationally. Within the numerical model of the FSW process component. The employed coupled Eulerian/Lagrangian computational analysis of the welding process

  16. Tidal Electric | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)Open Energy Information ThreeTianDi GrowthTibagiTidal

  17. Dispersion and Tidal Dynamics of Channel-Shoal Estuaries

    E-Print Network [OSTI]

    Holleman, Christopher Dean

    2013-01-01

    San Pablo Bay: ? M 2 and tidal energy flux for the hNS0? M 2 and tidal energy flux for hNS0. . . . . . . . . . .areas dissipate incident tidal energy, countering the added

  18. Practical application of large eddy simulation to film cooling flow analysis on gas turbine airfoils

    SciTech Connect (OSTI)

    Takata, T.; Takeishi, K.; Kawata, Y.; Tsuge, A.

    1999-07-01

    Large eddy simulation (LES) using body-fitted coordinates is applied to solve film cooling flow on turbine blades. The turbulent model was tuned using the experimental flow field and adiabatic film cooling effectiveness measurements for a single row of holes on a flat plate surface. The results show the interaction between the main stream boundary layer and injected film cooling air generates kidney and horseshoe shaped vortices. Comparison of the temperature distribution between experimental results and present analysis has been conducted. The non-dimensional temperature distribution at x/d = 1 is dome style and quantitatively agrees with experimental results. LES was also applied to solve film cooling on a turbine airfoil. If LES was applied to solve whole flow field domain large CPU time would make the solution impractical. LES, using body-fitted coordinates, is applied to solve the non-isotropic film cooling flow near the turbine blade. The cascade flow domain, with a pitch equal to one film cooling hole spacing, is solved using {kappa}-{epsilon} model. By using such a hybrid numerical method, CPU time is reduced and numerical accuracy is insured. The analytical results show the interaction between the flow blowing through film cooling holes and mainstream on the suction and pressure surfaces of the turbine airfoil. They also show the fundamental structure of the film cooling air flow is governed by arch internal secondary flow and horseshoe vortices which have a similar structure to film cooling air flow blowing through a cooling hole on a flat plate. In the flow field, the effect of turbulent structure on curvature (relaminarization) and flow pattern, involving the interaction between main flow and the cooling jet, are clearly shown. Film cooling effectiveness on the blade surface is predicted from the results of the thermal field calculation and is compared with the test result.

  19. Group Analysis An Electrophysiological Information Flow Toolbox for EEGLAB

    E-Print Network [OSTI]

    Makeig, Scott

    electrode channels suffers from a high risk of Type I errors from volume conduction and non-brain artifacts). Preprocessing Pre-processing is the first step in the SIFT analysis pipeline. SIFT 0.1a is currently restricted

  20. Flow distribution analysis on the cooling tube network of ITER thermal shield

    SciTech Connect (OSTI)

    Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun; Kang, Dong Kwon; Kang, Kyoung-O; Ahn, Hee Jae; Lee, Hyeon Gon

    2014-01-29

    Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube network for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.

  1. On the circulation and tidal flushing of Mobile Bay, Alabama 

    E-Print Network [OSTI]

    Austin, George Belden

    1953-01-01

    of Symbols, Tables ~ . . . I, INTRODUCTION Historical B. Classification of Estuaries C. Ob]ectives II. GENERAL DISCUSSION OF NOBILE BAY A. Geomorphological B. Geological C. Biological iii ~ ~ vi ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o sic.... Collection of Data 27 2B V, ANALYSIS OF THE DATA A. Methods B. Distribution of Temperature, Salinity, and Fresh Water Page 30 30 C. Circulation D. Mass Transport . E. Tidal Flushing of Mobile Bay . VI ~ SUMMAHY AND CONCLUSIONS VII, BIBLIOGRAPHY...

  2. Second law analysis of water flow through smooth microtubes under adiabatic conditions

    SciTech Connect (OSTI)

    Parlak, Nezaket; Guer, Mesut; Ari, Vedat; Kuecuek, Hasan; Engin, Tahsin [The University of Sakarya, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, 54187 Sakarya (Turkey)

    2011-01-15

    In the study, a second law analysis for a steady-laminar flow of water in adiabatic microtubes has been conducted. Smooth microtubes with the diameters between 50 and 150 {mu}m made of fused silica were used in the experiments. Considerable temperature rises due to viscous dissipation and relatively high pressure losses of flow were observed in experiments. To identify irreversibility of flow, rate of entropy generation from the experiments have been determined in the laminar flow range of Re = 20-2200. The second law of thermodynamics was applied to predict the entropy generation. The results of model taken from the literature, proposed to predict the temperature rise caused by viscous heating, correspond well with the experimental data. The second law analysis results showed that the flow characteristics in the smooth microtubes distinguish substantially from the conventional theory for flow in the larger tubes with respect to viscous heating/dissipation (temperature rise of flow) total entropy generation rate and lost work. (author)

  3. Sandia Energy - Tidal & Current Modeling Development and Validation

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

    Tidal & Current Modeling Development and Validation Home Stationary Power Energy Conversion Efficiency Water Power Technology Development Tidal & Current Modeling Development and...

  4. Symmetry group analysis of an ideal plastic flow

    E-Print Network [OSTI]

    Vincent Lamothe

    2011-02-11

    In this paper, we study the Lie point symmetry group of a system describing an ideal plastic plane flow in two dimensions in order to find analytical solutions. The infinitesimal generators that span the Lie algebra for this system are obtained. We completely classify the subalgebras of up to codimension two in conjugacy classes under the action of the symmetry group. Based on invariant forms, we use Ansatzes to compute symmetry reductions in such a way that the obtained solutions cover simultaneously many invariant and partially invariant solutions. We calculate solutions of the algebraic, trigonometric, inverse trigonometric and elliptic type. Some solutions depending on one or two arbitrary functions of one variable have also been found. In some cases, the shape of a potentially feasible extrusion die corresponding to the solution is deduced. These tools could be used to thin, curve, undulate or shape a ring in an ideal plastic material.

  5. Tidal deformations of a spinning compact object

    E-Print Network [OSTI]

    Pani, Paolo; Maselli, Andrea; Ferrari, Valeria

    2015-01-01

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole mom...

  6. A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows Seyed Ali Ale Etrati Khosroshahi

    E-Print Network [OSTI]

    Victoria, University of

    A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale Etrati-dimensional analysis of the performance of multi-element guard-heated hot-film wall shear stress microsensors

  7. Theoretical Analysis of Gate Level Information Flow Tracking

    E-Print Network [OSTI]

    Sherwood, Tim

    . This paper presents a theoretical analysis of GLIFT. It formalizes the problem, provides fundamental contributions of this paper are: 1) Defining and proving fundamental properties of GLIFT: We precisely define , Mohit Tiwari , Timothy Sherwood , and Ryan Kastner Computer Science and Engineering, University

  8. tidal form drag Sally Warner

    E-Print Network [OSTI]

    W lunar hours potential flow power = 0 Velocity Form drag Power Cumulative power flood slack residual power = total power ­ potential flow drag = residual drag total form drag . . Dynamicallyactive potential flow drag estimate wave drag ratio L Y d Isohalines above a ridge Pressure anomaly ~U0w #12;When

  9. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    SciTech Connect (OSTI)

    K. Rehfeldt

    2004-10-08

    This report is an updated analysis of water-level data performed to provide the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]) (referred to as the saturated zone (SZ) site-scale flow model or site-scale SZ flow model in this report) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for calibration of groundwater flow models. This report also contains an expanded discussion of uncertainty in the potentiometric-surface map. The analysis of the potentiometric data presented in Revision 00 of this report (USGS 2001 [DIRS 154625]) provides the configuration of the potentiometric surface, target heads, and hydraulic gradients for the calibration of the SZ site-scale flow model (BSC 2004 [DIRS 170037]). Revision 01 of this report (USGS 2004 [DIRS 168473]) used updated water-level data for selected wells through the year 2000 as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain based on an alternative interpretation of perched water conditions. That revision developed computer files containing: Water-level data within the model area (DTN: GS010908312332.002); A table of known vertical head differences (DTN: GS010908312332.003); and A potentiometric-surface map (DTN: GS010608312332.001) using an alternative concept from that presented by USGS (2001 [DIRS 154625]) for the area north of Yucca Mountain. The updated water-level data presented in USGS (2004 [DIRS 168473]) include data obtained from the Nye County Early Warning Drilling Program (EWDP) Phases I and II and data from Borehole USW WT-24. This document is based on Revision 01 (USGS 2004 [DIRS 168473]) and expands the discussion of uncertainty in the potentiometric-surface map. This uncertainty assessment includes an analysis of the impact of more recent water-level data and the impact of adding data from the EWDP Phases III and IV wells. In addition to being utilized by the SZ site-scale flow model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for groundwater management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model and provides information useful to estimation of the magnitude and direction of lateral groundwater flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment (TSPA).

  10. Stability analysis of the Witten black hole (cigar soliton) under world-sheet RG flow

    E-Print Network [OSTI]

    Carolyn Lambert; Vardarajan Suneeta

    2012-09-01

    We analyze the stability of the Euclidean Witten black hole (the cigar soliton in mathematics literature) under first-order RG (Ricci) flow of the world-sheet sigma model. This analysis is from the target space point of view. We find that the Witten black hole has no unstable normalizable perturbative modes in a linearized mode analysis in which we consider circularly symmetric perturbations. Finally, we discuss a result from mathematics that implies the existence of a non-normalizable mode of the Witten black hole under which the geometry flows to the sausage solution studied by Fateev, Onofri and Zamolodchikov.

  11. EQUATORIAL SUPERROTATION ON TIDALLY LOCKED EXOPLANETS

    SciTech Connect (OSTI)

    Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, 1629 University Blvd., Tucson, AZ 85721 (United States); Polvani, Lorenzo M., E-mail: showman@lpl.arizona.edu [Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY (United States)

    2011-09-01

    The increasing richness of exoplanet observations has motivated a variety of three-dimensional (3D) atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or 'superrotating', jet stream at the equator. When the radiative and advection timescales are comparable, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been subsequently observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing Rossby waves induced by the day-night thermal forcing. The strong longitudinal variations in radiative heating-namely intense dayside heating and nightside cooling-trigger the formation of standing, planetary-scale equatorial Rossby and Kelvin waves. The Rossby waves develop phase tilts that pump eastward momentum from high latitudes to the equator, thereby inducing equatorial superrotation. We present an analytic theory demonstrating this mechanism and explore its properties in a hierarchy of one-layer (shallow-water) calculations and fully 3D models. The wave-mean-flow interaction produces an equatorial jet whose latitudinal width is comparable to that of the Rossby waves, namely the equatorial Rossby deformation radius modified by radiative and frictional effects. For conditions typical of synchronously rotating hot Jupiters, this length is comparable to a planetary radius, explaining the broad scale of the equatorial jet obtained in most hot-Jupiter models. Our theory illuminates the dependence of the equatorial jet speed on forcing amplitude, strength of friction, and other parameters, as well as the conditions under which jets can form at all.

  12. Version: 6/16/98 Keywords: wavy surface flow, finite element, longwave analysis, weakly-nonlinear analysis

    E-Print Network [OSTI]

    McCready, Mark J.

    Version: 6/16/98 Keywords: wavy surface flow, finite element, longwave analysis, weakly and drag are found, from finite element calculations, to increase as amplitude to approximately the third wavelength problem is solved numerically with a finite element formulation providing qualitative trends

  13. EA-1916: Ocean Renewable Power Company Maine, LLC Cobscook Bay Tidal Energy Pilot Project, Cobscook in Washington County, Maine

    Broader source: Energy.gov [DOE]

    Draft Environmental AssessmentThis EA evaluates the environmental impacts of a project that would use the tidal currents of Cobscook Bay to generate electricity via cross-flow Kinetic System turbine generator units (TGU) mounted on the seafloor. The TGUs would capture energy from the flow in both ebb and flood directions.

  14. Tidal deformations of a spinning compact object

    E-Print Network [OSTI]

    Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari

    2015-06-30

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the multipole moments of the central object, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.

  15. Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a

    E-Print Network [OSTI]

    Abdou, Mohamed

    2006-01-01

    Fusion Engineering and Design 81 (2006) 549­553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made

  16. Study of vaneless diffuser rotating stall based on two-dimensional inviscid flow analysis

    SciTech Connect (OSTI)

    Tsujimoto, Yoshinobu; Yoshida, Yoshiki [Osaka Univ., Toyonaka, Osaka (Japan); Mori, Yasumasa [Mitsubishi Motors Corp., Ohta, Tokyo (Japan)

    1996-03-01

    Rotating stalls in vaneless diffusers are studied from the viewpoint that they are basically two-dimensional inviscid flow instability under the boundary conditions of vanishing velocity disturbance at the diffuser inlet and of vanishing pressure disturbance at the diffuser outlet. The linear analysis in the present report shows that the critical flow angle and the propagation velocity are functions of only the diffuser radius ratio. It is shown that the present analysis can reproduce most of the general characteristics observed in experiments: critical flow angle, propagation velocity, velocity, and pressure disturbance fields. It is shown that the vanishing velocity disturbance at the diffuser inlet is caused by the nature of impellers as a resistance and an inertial resistance, which is generally strong enough to suppress the velocity disturbance at the diffuser inlet. This explains the general experimental observations that vaneless diffuser rotating stalls are not largely affected by the impeller.

  17. UNDERSTANDING FLOW OF ENERGY IN BUILDINGS USING MODAL ANALYSIS METHODOLOGY

    SciTech Connect (OSTI)

    John Gardner; Kevin Heglund; Kevin Van Den Wymelenberg; Craig Rieger

    2013-07-01

    It is widely understood that energy storage is the key to integrating variable generators into the grid. It has been proposed that the thermal mass of buildings could be used as a distributed energy storage solution and several researchers are making headway in this problem. However, the inability to easily determine the magnitude of the building’s effective thermal mass, and how the heating ventilation and air conditioning (HVAC) system exchanges thermal energy with it, is a significant challenge to designing systems which utilize this storage mechanism. In this paper we adapt modal analysis methods used in mechanical structures to identify the primary modes of energy transfer among thermal masses in a building. The paper describes the technique using data from an idealized building model. The approach is successfully applied to actual temperature data from a commercial building in downtown Boise, Idaho.

  18. Rheo-PIV Analysis of the Yielding and Flow of Model Waxy Crude Oils

    E-Print Network [OSTI]

    Rheo-PIV Analysis of the Yielding and Flow of Model Waxy Crude Oils Christopher J. Dimitriou@mit.edu Abstract Waxes are a commonly encountered precipitate that can result in gelation of crude oils behavior similar to waxy crude oils encountered in production scenarios. To study the consequences

  19. Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed Generator Units with

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    Power Flow Analysis Algorithm for Islanded LV Microgrids Including Distributed Generator Units power system. Being able to operate in both grid-connected and islanded mode, a microgrid manages and controls distributed energy resources, energy storage systems and loads, most of them are power electronic

  20. Continuous Flow Analysis of Total Organic Carbon in Polar Ice Cores

    E-Print Network [OSTI]

    Stocker, Thomas

    Continuous Flow Analysis of Total Organic Carbon in Polar Ice Cores U R S F E D E R E R , * , , P, University of Bern, Bern, Switzerland, Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland, and British Antarctic Survey, Cambridge, United Kingdom Received May 6, 2008. Revised manuscript

  1. IDS120h GEOMETRY WITH SHIELDING VESSELS ENERGY FLOW ANALYSIS CONTINUED

    E-Print Network [OSTI]

    McDonald, Kirk

    IDS120h GEOMETRY WITH SHIELDING VESSELS ENERGY FLOW ANALYSIS CONTINUED SHIELDING MATERIAL: 60% W with shielding vessels. # Different cases of shielding material. # N = 100,000 AND N = 500,000 events simulations CUTOFF >SHIELDING: 60% W + 40% He , 80% W + 20% He, 88% W + 12% He ( WITH W VESSELS) >4 MW proton beam

  2. Evolution of Near-surface Flows Inferred from High-resolution Ring-diagram Analysis

    E-Print Network [OSTI]

    Bogart, Richard S; Baldner,; Basu, Sarbani

    2015-01-01

    Ring-diagram analysis of acoustic waves observed at the photosphere can provide a relatively robust determination of the sub-surface flows at a particular time under a particular region. The depth of penetration of the waves is related to the size of the region, hence the depth extent of the measured flows is inversely proportional to the spatial resolution. Most ring-diagram analysis has focused on regions of extent ~15{\\deg} (180 Mm) or more in order to provide reasonable mode sets for inversions. HMI data analysis also provides a set of ring fit parameters on a scale three times smaller. These provide flow estimates for the outer 1% (7 Mm) of the Sun only, with very limited depth resolution, but with spatial resolution adequate to map structures potentially associated with the belts and regions of magnetic activity. There are a number of systematic effects affecting the determination of flows from local helioseismic analysis of regions over different parts of the observable disk, not all well understood. I...

  3. Wood anatomical analysis of Alnus incana and Betula pendula injured by a debris-flow event

    E-Print Network [OSTI]

    Butler, David R. - Department of Geography, Texas State University

    Wood anatomical analysis of Alnus incana and Betula pendula injured by a debris-flow event ESTELLE. More- over, time series of wood anatomical features have only rarely been used to reconstruct former geomorphic events. This study was therefore undertaken to characterize the wood anatomical response

  4. Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1 Gary S. Grest,2 James February 2006; published 24 August 2006 Pebble-bed nuclear reactor technology, which is currently being States, the Modular Pebble Bed Reactor MPBR 4,8 is a candidate for the next generation nuclear plant

  5. Electro-osmotic flow control for living cell analysis in microfluidic Tomasz Glawdel, Carolyn L. Ren *

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Electro-osmotic flow control for living cell analysis in microfluidic PDMS chips Tomasz Glawdel April 2008 Received in revised form 20 June 2008 Available online 10 July 2008 Keywords: Electro-osmotic lines each of which consists of an integrated elec- tro-osmotic pump, a cell culture chamber

  6. Aalborg Universitet Power flow analysis for droop controlled LV hybrid AC-DC microgrids with virtual

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Power flow analysis for droop controlled LV hybrid AC-DC microgrids controlled LV hybrid AC-DC microgrids with virtual impedance. In Proceedings of the IEEE Power & Energy Interlinking converter PV WT IBS DC microgrid DC microgrid AC microgrid AC Load Figure 1. Structure

  7. The structural sensitivity of open shear flows calculated with a local stability analysis

    E-Print Network [OSTI]

    Juniper, Matthew P.; Pier, Benoit

    2014-01-01

    calculated with 2D or 3D global stability analyses, which can be very computationally expensive. For weakly non-parallel flows the direct global mode can also be calculated with a local stability analysis, which is orders of magnitude cheaper...

  8. Numerical Analysis of a Mixed Finite Element Method for a FlowTransport Problem

    E-Print Network [OSTI]

    Chou, So-Hsiang

    a waste­ disposal problem in which high level radioactive waste is buried in a salt dome, the salt dissolves to create a brine, radioactive elements decay to generate heat, and radionuclides are transportedNumerical Analysis of a Mixed Finite Element Method for a Flow­Transport Problem S. H. CHOU AND Q

  9. Analysis of Pt/C electrode performance in a flowing-electrolyte alkaline fuel cell

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Analysis of Pt/C electrode performance in a flowing- electrolyte alkaline fuel cell Fikile R cell Electrode characterization X-ray micro-computed tomography Microfluidic fuel cell Carbonates a b a microfluidic H2/O2 fuel cell as an analytical platform. Both anodes and cathodes were investigated

  10. Animation and Visualization of Spot Prices via Quadratized Power Flow Analysis

    E-Print Network [OSTI]

    Animation and Visualization of Spot Prices via Quadratized Power Flow Analysis A. P. Sakis@attbi.com Abstract This paper presents a new model for efficient calculation of spot prices and animation and visualization of spot price evolution as the system operating point is changing. The computational method

  11. Paper No. 9.06 1 NEWMARKIAN ANALYSIS OF LIQUEFIED FLOW IN CENTRIFUGE MODEL

    E-Print Network [OSTI]

    Haigh, Stuart

    Paper No. 9.06 1 NEWMARKIAN ANALYSIS OF LIQUEFIED FLOW IN CENTRIFUGE MODEL EARTHQUAKES S.K. Haigh S-pressure history either predicted using a suitable constitutive model, or measured during a centrifuge or shaking displacements using this procedure and displacements measured in centrifuge model tests with the same pore

  12. AIAA Paper 2006-0102 Analysis of Jet Effects on Co-Flow Jet Airfoil

    E-Print Network [OSTI]

    Zha, Gecheng

    engine inlet j jet injection Freestream Greek Letters: Turbulent Dissipation Rate Ratio of SpecificAIAA Paper 2006-0102 Analysis of Jet Effects on Co-Flow Jet Airfoil Performance with Integrated Propulsion System Ge-Cheng Zha and Wei Gao Dept. of Mechanical and Aerospace Engineering University of Miami

  13. 12th Annual Wave & Tidal 2015

    Broader source: Energy.gov [DOE]

    The UK is currently the undisputed global leader in marine energy, with more wave and tidal stream devices installed than the rest of the world combined. This leading position is built on an...

  14. Naturalized plants have smaller genomes than their non-invading relatives: a flow cytometric analysis of the Czech alien flora

    E-Print Network [OSTI]

    Kratochvíl, Lukas

    analysis of the Czech alien flora Naturalizované rostliny mají mensí genom nez neinvadující druhy than their non-invading relatives: a flow cytometric analysis of the Czech alien flora. ­ Preslia 82 in 93 alien species naturalized in the Czech Republic, belonging to 32 families, by using flow cytometry

  15. FAINT TIDAL FEATURES IN GALAXIES WITHIN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY WIDE FIELDS

    SciTech Connect (OSTI)

    Atkinson, Adam M.; Abraham, Roberto G.; Ferguson, Annette M. N.

    2013-03-01

    We present an analysis of the detectability of faint tidal features in galaxies from the wide-field component of the Canada-France-Hawaii Telescope Legacy Survey. Our sample consists of 1781 luminous (M{sub r{sup '}}<-19.3 mag) galaxies in the magnitude range 15.5 mag < r' < 17 mag and in the redshift range 0.04 < z < 0.2. Although we have classified tidal features according to their morphology (e.g., streams, shells, and tails), we do not attempt to interpret them in terms of their physical origin (e.g., major versus minor merger debris). Instead, we provide a catalog that is intended to provide raw material for future investigations which will probe the nature of low surface brightness substructure around galaxies. We find that around 12% of the galaxies in our sample show clear tidal features at the highest confidence level. This fraction rises to about 18% if we include systems with convincing, albeit weaker tidal features, and to 26% if we include systems with more marginal features that may or may not be tidal in origin. These proportions are a strong function of rest-frame color and of stellar mass. Linear features, shells, and fans are much more likely to occur in massive galaxies with stellar masses >10{sup 10.5} M {sub Sun }, and red galaxies are twice as likely to show tidal features than are blue galaxies.

  16. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    SciTech Connect (OSTI)

    Othman, M. N. K. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Hazry, D. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Khairunizam, Wan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Shahriman, A. B. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Yaacob, S. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  17. Stochastic analysis of the time evolution of Laminar-Turbulent bands of plane Couette flow

    E-Print Network [OSTI]

    Rolland, Joran

    2015-01-01

    This article is concerned with the time evolution of the oblique laminar-turbulent bands of transitional plane Couette flow under the influence of turbulent noise. Our study is focused on the amplitude of modulation of turbulence. In order to guide the numerical study of the flow, we first perform an analytical and numerical analysis of a Stochastic Ginzburg-Landau equation for a complex order parameter. The modulus of this order parameter models the amplitude of modulation of turbulence. Firstly, we compute the autocorrelation function of said modulus once the band is established. Secondly, we perform a calculation of average and fluctuations around the exponential growth of the order parameter. This type of analysis is similar to the Stochastic Structural Stability Theory. We then perform numerical simulations of the Navier-Stokes equations in order to confront these predictions with the actual behaviour of the bands. Computation of the autocorrelation function of the modulation of turbulence shows quantita...

  18. ANALYSIS OF TWO-PHASE FLOW MODELS WITH TWO MOMENTUM EQUATIONS.

    SciTech Connect (OSTI)

    KROSHILIN,A.E.KROSHILIN,V.E.KOHUT,P.

    2004-03-15

    An analysis of the standard system of differential equations describing multi-speed flows of multi-phase media is performed. It is proved that the Cauchy problem, as posed in most best-estimate thermal-hydraulic codes, results in unstable solutions and potentially unreliable description of many physical phenomena. A system of equations, free from instability effects, is developed allowing more rigorous numerical modeling.

  19. A comparison of an analytical and two electric analogy methods of hydraulic flow analysis 

    E-Print Network [OSTI]

    Hoffman, Joe Douglas

    1959-01-01

    ~ THE LINEAR RESISTANCE EIKCTRIC ANAIOGY METHOD . . . . . . 57 IX ~ THE NON-LINEAR RESISTANCE ELECTRIC ANALOGY METHOD, . 75 Xo DISCUSSION OF RESULTS XIo CONCLUSIONS APPENDIX BIBLIOGRAPHY 95 101 104 109 I, INTRODUCTION Although networks of hydraulic... pipelines are used throughout the world, the analysis of their steady state performance is a difficult and time consuming process . The work involved in ana- lysing a network of pipelines to determine flow rates and energy losses throughout the network...

  20. A parallel and matrix free framework for global stability analysis of compressible flows

    E-Print Network [OSTI]

    Henze, O; Sesterhenn, J

    2015-01-01

    An numerical iterative framework for global modal stability analysis of compressible flows using a parallel environment is presented. The framework uses a matrix-free implementation to allow computations of large scale problems. Various methods are tested with regard to convergence acceleration of the framework. The methods consist of a spectral Cayley transformation used to select desired Eigenvalues from a large spectrum, an improved linear solver and a parallel block-Jacobi preconditioning scheme.

  1. Three dimensional finite element analysis of the flow of polymer melts

    E-Print Network [OSTI]

    Jimack, Peter

    Three dimensional finite element analysis of the flow of polymer melts R. Tencheva , T. Goughb , O.G, LS2 9JT, UK. b School of Engineering, Design & Technology, University of Bradford, Bradford, BD7 1DP.g.harlen@leeds.ac.uk (O.G. Harlen), p.k.jimack@leeds.ac.uk (P.K. Jimack), h.klein@leeds.ac.uk (D.H. Klein), m

  2. TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING

    SciTech Connect (OSTI)

    Thomson, Jim; Kilcher, Levi; Richmond, Marshall C.; Talbert, Joe; deKlerk, Alex; Polagye, Brian; Guerra, Maricarmen; Cienfuegos, Rodrigo

    2013-06-13

    A compliant mooring to collect high frequency turbulence data at a tidal energy site is evaluated in a series of short demon- stration deployments. The Tidal Turbulence Mooring (TTM) improves upon recent bottom-mounted approaches by suspend- ing Acoustic Doppler Velocimeters (ADVs) at mid-water depths (which are more relevant to tidal turbines). The ADV turbulence data are superior to Acoustic Doppler Current Profiler (ADCP) data, but are subject to motion contamination when suspended on a mooring in strong currents. In this demonstration, passive stabilization is shown to be sufficient for acquiring bulk statistics of the turbulence, without motion correction. With motion cor- rection (post-processing), data quality is further improved; the relative merits of direct and spectral motion correction are dis- cussed.

  3. Measuring the CO2 flux at the air/water interface in lakes using flow injection analysis

    E-Print Network [OSTI]

    Jardim, Wilson de Figueiredo

    measurements. The use of flow analysis for the determination of dissolved carbon dioxide by membrane separation a hydrophobic membrane into a flow of deionized water, generating a gradient of conductivity proportional the processes related to the carbon cycle within the aquatic environment. The direction of CO2 gas exchange

  4. Assessment of Energy Production Potential from Tidal Streams...

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

    project documented in this report created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal...

  5. The rotation and fracture history of Europa from modeling of tidal-tectonic processes

    E-Print Network [OSTI]

    Rhoden, Alyssa Rose

    2011-01-01

    the tidal stresses. They adopted a power-law viscoelasticpower of the model. However, the mechanics of tidal walking

  6. Analysis of instability inception in high-speed multistage axial-flow compressors

    SciTech Connect (OSTI)

    Hendricks, G.J.; Sabnis, J.S.; Feulner, M.R.

    1997-10-01

    A nonlinear, two-dimensional, compressible dynamic model has been developed to study rotating stall/surge inception and development in high-speed, multistage, axial flow compressors. The flow dynamics are represented by the unsteady Euler equations, solved in each interblade row gap and inlet and exit ducts as two-dimensional domains, and in each blade passage as a one-dimensional domain. The resulting equations are solved on a computational grid. The boundary conditions between domains are represented by ideal turning coupled with empirical loss and deviation correlations. Results are presented comparing model simulations to instability inception data of an eleven stage, high-pressure-ratio compressor operating at both part and full power, and the results analyzed in the context of a linear modal analysis.

  7. Tidal networks 2. Watershed delineation and comparative network morphology

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    of three, we quantify various tidal network properties including common power law relationships which have common power law relationships quantified for terrestrial systems to tidal systems and use these analysesTidal networks 2. Watershed delineation and comparative network morphology Andrea Rinaldo,1 Sergio

  8. Enhancing Electrical Supply by Pumped Storage in Tidal Lagoons

    E-Print Network [OSTI]

    MacKay, David J.C.

    to demand into high­value demand­following power; and second, it can simultaneously serve as a tidal powerEnhancing Electrical Supply by Pumped Storage in Tidal Lagoons David J.C. MacKay Cavendish/3/07 Summary The principle that the net energy delivered by a tidal pool can be increased by pumping extra

  9. Rotational stability of tidally deformed planetary I. Matsuyama1

    E-Print Network [OSTI]

    Nimmo, Francis

    Rotational stability of tidally deformed planetary bodies I. Matsuyama1 and F. Nimmo2 Received 11 consider the true polar wander (rotational variations driven by mass redistribution) of tidally deformed planetary bodies. The rotation pole of bodies without tidal deformation is stabilized by the component

  10. Research papers Tidal characteristics of the gulf of Tonkin

    E-Print Network [OSTI]

    calibration derived from a set of sensitivity experiments to model parameters. The tidal energy budgetResearch papers Tidal characteristics of the gulf of Tonkin Nguyen Nguyet Minh a,c , Marchesiello of this study is to revisit the dominant physical processes that characterize tidal dynamics in the Gulf

  11. Three parameter flow cytometric analysis for simultaneous detection of cytokeratin, proliferation associated antigens and DNA content

    SciTech Connect (OSTI)

    Schutte, B.; Pijpers, G.F.P.; Lenders, M.H.J.H.; Ramaekers, F.C.S. [Univ. of Limburg (Netherlands)

    1995-10-01

    The analysis of the cell cycle distributions by univariate flow cytometric DNA measurement has been widely applied in the clinic to determine kinetic parameters of human malignancies. A common problem with measurements of cell cycle phase distributions in tumor biopsy material is the presence of nonmalignant diploid cells. Furthermore, such a static measurement might not be accurate enough to describe the dynamic process of cell proliferation. For this purpose alternative methods have been developed to include BrdUrd incorporation or the presence of intrinsic proliferation associated markers such as PCNA or Ki67-Ag into the analysis. However, the presence of nonmalignant diploid cells will influence also these bivariate analyses, especially in case of DNA-diploidy of the tumor cells. Here we present a three parameter flow cytometric assay based on the simultaneous detection of cytokeratin, DNA and a proliferation associated marker, such as BrdUrd, PCNA or Ki67-Ag. Based on the presence of cytokeratin, epithelial cells can be selected for a detailed cell cycle analysis. This method can be applied to frozen tissue, which makes this assay useful for multicentre clinical studies. 25 refs., 8 figs.

  12. Puget Sound Tidal Energy In-Water Testing and Development Project Final Technical Report

    SciTech Connect (OSTI)

    Craig W. Collar

    2012-11-16

    Tidal energy represents potential for the generation of renewable, emission free, environmentally benign, and cost effective energy from tidal flows. A successful tidal energy demonstration project in Puget Sound, Washington may enable significant commercial development resulting in important benefits for the northwest region and the nation. This project promoted the United States Department of Energy�s Wind and Hydropower Technologies Program�s goals of advancing the commercial viability, cost-competitiveness, and market acceptance of marine hydrokinetic systems. The objective of the Puget Sound Tidal Energy Demonstration Project is to conduct in-water testing and evaluation of tidal energy technology as a first step toward potential construction of a commercial-scale tidal energy power plant. The specific goal of the project phase covered by this award was to conduct all activities necessary to complete engineering design and obtain construction approvals for a pilot demonstration plant in the Admiralty Inlet region of the Puget Sound. Public Utility District No. 1 of Snohomish County (The District) accomplished the objectives of this award through four tasks: Detailed Admiralty Inlet Site Studies, Plant Design and Construction Planning, Environmental and Regulatory Activities, and Management and Reporting. Pre-Installation studies completed under this award provided invaluable data used for site selection, environmental evaluation and permitting, plant design, and construction planning. However, these data gathering efforts are not only important to the Admiralty Inlet pilot project. Lessons learned, in particular environmental data gathering methods, can be applied to future tidal energy projects in the United States and other parts of the world. The District collaborated extensively with project stakeholders to complete the tasks for this award. This included Federal, State, and local government agencies, tribal governments, environmental groups, and others. All required permit and license applications were completed and submitted under this award, including a Final License Application for a pilot hydrokinetic license from the Federal Energy Regulatory Commission. The tasks described above have brought the project through all necessary requirements to construct a tidal pilot project in Admiralty Inlet with the exception of final permit and license approvals, and the selection of a general contractor to perform project construction.

  13. Analysis of alternatives for computing backwater at bridges for free-surface, subcritical flow conditions 

    E-Print Network [OSTI]

    Kaatz, Kelly Jay

    1993-01-01

    . (August 1993) Kelly Jay Kaatz, B. S. , Texas A&M University Chair of Advisory Committee: Dr. Wesley P. James The performance and reliability of four of the more popular methods for one- dimensional flow analysis of bridges were investigated. These four... methods were the HEC-2 Normal Bridge Method, HEC-2 Special Bridge Method, WSPRO, and Modified Bradley Method. The study was based on models of 13 flood events at nine different bridge sites in the southeastern United States. The sites were located...

  14. Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis 

    E-Print Network [OSTI]

    Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

    2006-01-01

    , Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-8-4 Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis1 Chenghu Zhang Ronghua Wu Guitao Li Xin Li Lei Huang Dexing Sun Doctor Master...) By the numeric calculation and the simplification, the power function form, can be obtained, which is used in the engineering easily. It is 0.30 0.0235 w d? = (2) The result of (2) is slight bigger than that of (1), but the errors are within 3...

  15. Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model

    SciTech Connect (OSTI)

    Cole, Charles R.; Bergeron, Marcel P.; Murray, Christopher J.; Thorne, Paul D.; Wurstner, Signe K.; Rogers, Phillip M.

    2001-11-09

    Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.

  16. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01

    the semidiurnal kinetic and potential energies, phasethe baroclinic kinetic and potential energy, respectively.both the kinetic and the potential energy start dropping

  17. Tidal heating of Earth-like exoplanets around M stars: Thermal, magnetic, and orbital evolutions

    E-Print Network [OSTI]

    Driscoll, Peter

    2015-01-01

    The internal thermal and magnetic evolution of rocky exoplanets is critical to their habitability. We focus on the thermal-orbital evolution of Earth-mass planets around low mass M stars whose radiative habitable zone overlaps with the "tidal zone". We develop a thermal-orbital evolution model calibrated to Earth that couples tidal dissipation, with a temperature-dependent Maxwell rheology, to orbital circularization and migration. We illustrate thermal-orbital steady states where surface heat flow is balanced by tidal dissipation and cooling can be stalled for billions of years until circularization occurs. Orbital energy dissipated as tidal heat in the interior drives both inward migration and circularization, with a circularization time that is inversely proportional to the dissipation rate. We identify a peak in the internal dissipation rate as the mantle passes through a visco-elastic state at mantle temperatures near 1800 K. Planets orbiting a 0.1 solar-mass star within $0.07$ AU circularize before 10 G...

  18. Legal strategies for protecting instream flows in Texas: an analysis of stakeholder preferences 

    E-Print Network [OSTI]

    Binion, Michael Shane

    1996-01-01

    's legal framework for implementing instream flows; an equitable and fair process; and the quantification of flows necessary for instream protection. Respondents also generally fell into three categories of satisfaction with current instream flow practices...

  19. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect (OSTI)

    Henning, Wade G.; Hurford, Terry

    2014-07-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  20. Tidal Energy Resource Assessment | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsState ofSavings for Specific2HeldTidal Energy Resource

  1. Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

    SciTech Connect (OSTI)

    Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Sustainability and proximity principles have a key role in waste management. Black-Right-Pointing-Pointer Core indicators are needed in order to quantify and evaluate them. Black-Right-Pointing-Pointer A systematic, step-by-step approach is developed in this study for their development. Black-Right-Pointing-Pointer Transport may play a significant role in terms of environmental and economic costs. Black-Right-Pointing-Pointer Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning.

  2. Tidal Energy System for On-Shore Power Generation

    SciTech Connect (OSTI)

    Bruce, Allan J

    2012-06-26

    Addressing the urgent need to develop LCOE competitive renewable energy solutions for US energy security and to replace fossil-fuel generation with the associated benefits to environment impacts including a reduction in CO2 emissions, this Project focused on the advantages of using hydraulic energy transfer (HET) in large-scale Marine Hydrokinetic (MHK) systems for harvesting off-shore tidal energy in US waters. A recent DOE resource assessment, identifies water power resources have a potential to meet 15% of the US electric supply by 2030, with MHK technologies being a major component. The work covered a TRL-4 laboratory proof-in-concept demonstration plus modeling of a 15MW full scale system based on an approach patented by NASA-JPL, in which submerged high-ratio gearboxes and electrical generators in conventional MHK turbine systems are replaced by a submerged hydraulic radial pump coupled to on-shore hydraulic motors driving a generator. The advantages are; first, the mean-time-between-failure (MTBF), or maintenance, can be extended from approximately 1 to 5 years and second, the range of tidal flow speeds which can be efficiently harvested can be extended beyond that of a conventional submerged generator. The approach uses scalable, commercial-off-the-shelf (COTS) components, facilitating scale-up and commercialization. All the objectives of the Project have been successfully met (1) A TRL4 system was designed, constructed and tested. It simulates a tidal energy turbine, with a 2-m diameter blade in up to a 2.9 m/sec flow. The system consists of a drive motor assembly providing appropriate torque and RPM, attached to a radial piston pump. The pump circulates pressurized, environmentally-friendly, HEES hydraulic fluid in a closed loop to an axial piston motor which drives an electrical generator, with a resistive load. The performance of the components, subsystems and system were evaluated during simulated tidal cycles. The pump is contained in a tank for immersion testing. The COTS pump and motor were selected to scale to MW size and were oversized for the TRL-4 demonstration, operating at only 1-6% of rated values. Nevertheless, in for 2-18 kW drive power, in agreement with manufacturer performance data, we measured efficiencies of 85-90% and 75-80% for the pump and motor, respectively. These efficiencies being 95-96% at higher operating powers. (2) Two follow-on paths were identified. In both cases conventional turbine systems can be modified, replacing existing gear box and generator with a hydraulic pump and on-shore components. On a conventional path, a TRL5/6 15kW turbine system can be engineered and tested on a barge at an existing site in Maine. Alternatively, on an accelerated path, a TRL-8 100kW system can be engineered and tested by modifying a team member's existing MHK turbines, with barge and grid-connected test sites in-place. On both paths the work can be expedited and cost effective by reusing TRL-4 components, modifying existing turbines and using established test sites. (3) Sizing, performance modeling and costing of a scaled 15MW system, suitable for operation in Maine's Western Passage, was performed. COTS components are identified and the performance projections are favorable. The estimated LCOE is comparable to wind generation with peak production at high demand times. (4) We determined that a similar HET approach can be extended to on-shore and off-shore wind turbine systems. These are very large energy resources which can be addressed in parallel for even great National benefit. (5) Preliminary results on this project were presented at two International Conferences on renewable energy in 2012, providing a timely dissemination of information. We have thus demonstrated a proof-in-concept of a novel, tidal HET system that eliminates all submerged gears and electronics to improve reliability. Hydraulic pump efficiencies of 90% have been confirmed in simulated tidal flows between 1 and 3 m/s, and at only 1-6% of rated power. Total system efficiencies have also been modeled, up to MW-scale, for ti

  3. Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska FINAL REPORT

    SciTech Connect (OSTI)

    Wright, Bruce Albert

    2014-05-07

    The Aleutian Pribilof Islands Association was awarded a U.S. Department of Energy Tribal Energy Program grant (DE-EE0005624) for the Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska (Project). The goal of the Project was to perform a feasibility study to determine if a tidal energy project would be a viable means to generate electricity and heat to meet long-term fossil fuel use reduction goals, specifically to produce at least 30% of the electrical and heating needs of the tribally-owned buildings in False Pass. The Project Team included the Aleut Region organizations comprised of the Aleutian Pribilof Island Association (APIA), and Aleutian Pribilof Island Community Development Association (APICDA); the University of Alaska Anchorage, ORPC Alaska a wholly-owned subsidiary of Ocean Renewable Power Company (ORPC), City of False Pass, Benthic GeoScience, and the National Renewable Energy Laboratory (NREL). The following Project objectives were completed: collected existing bathymetric, tidal, and ocean current data to develop a basic model of current circulation at False Pass, measured current velocities at two sites for a full lunar cycle to establish the viability of the current resource, collected data on transmission infrastructure, electrical loads, and electrical generation at False Pass, performed economic analysis based on current costs of energy and amount of energy anticipated from and costs associated with the tidal energy project conceptual design and scoped environmental issues. Utilizing circulation modeling, the Project Team identified two target sites with strong potential for robust tidal energy resources in Isanotski Strait and another nearer the City of False Pass. In addition, the Project Team completed a survey of the electrical infrastructure, which identified likely sites of interconnection and clarified required transmission distances from the tidal energy resources. Based on resource and electrical data, the Project Team developed a conceptual tidal energy project design utilizing ORPC’s TidGen® Power System. While the Project Team has not committed to ORPC technology for future development of a False Pass project, this conceptual design was critical to informing the Project’s economic analysis. The results showed that power from a tidal energy project could be provided to the City of False at a rate at or below the cost of diesel generated electricity and sold to commercial customers at rates competitive with current market rates, providing a stable, flat priced, environmentally sound alternative to the diesel generation currently utilized for energy in the community. The Project Team concluded that with additional grants and private investment a tidal energy project at False Pass is well-positioned to be the first tidal energy project to be developed in Alaska, and the first tidal energy project to be interconnected to an isolated micro grid in the world. A viable project will be a model for similar projects in coastal Alaska.

  4. Development of a flow injection analysis method for the determination of acrylamide copolymers in oilfield brines

    SciTech Connect (OSTI)

    Taylor, K.C.; Burke, R.A.; Schramm, L.L. [Petroleum Recovery Inst., Calgary, Alberta (Canada); Nasr-El-Din, H.A. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-11-01

    An automated method for the determination of acrylamide polymers by flow injection analysis (FIA) has been developed and optimized for routine use. The method has been extensively tested for interferences common in oilfield brines. Potential interferences were examined from Na{sup +}, Ca{sup 2+}, Cr{sup 3+}, Al{sup 3+}, Zr{sup 3+}, NH{sub 4}{sup +}, Cl{sup {minus}}, OH{sup {minus}}, CO{sub 3}{sup 2{minus}}, sample coloration, and commonly used surfactants. The analysis is specific for amides, and the sensitivity to concentration of amide groups in the polymer was shown to be constant as the degree of polymer hydrolysis was varied. The range of the method is 0.1 to 100 mg/L. Sample throughput is 30 samples/h with triplicate analysis. Relative standard deviations of 0.2% are readily obtained from standard solutions and 0.5% from complex samples (at 50 mg/L). The method is applicable to the determination of aqueous, acrylamide-based polymers in process streams, surface waters and oilfield brines.

  5. "Circularization" vs. Accretion -- What Powers Tidal Disruption Events?

    E-Print Network [OSTI]

    Piran, Tsvi; Krolik, Julian; Cheng, Roseanne M; Shiokawa, Hotaka

    2015-01-01

    A tidal disruption event (TDE) takes place when a star passes near enough to a massive black hole to be disrupted. About half the star's matter is given elliptical trajectories with large apocenter distances, the other half is unbound. To "circularize", i.e., to form an accretion flow, the bound matter must lose a significant amount of energy, with the actual amount depending on the characteristic scale of the flow measured in units of the black hole's gravitational radius (~ 10^{51} (R/1000R_g)^{-1} erg). Recent numerical simulations (Shiokawa et al., 2015) have revealed that the circularization scale is close to the scale of the most-bound initial orbits, ~ 10^3 M_{BH,6.5}^{-2/3} R_g ~ 10^{15} M_{BH,6.5}^{1/3} cm from the black hole, and the corresponding circularization energy dissipation rate is $\\sim 10^{44} M_{BH,6.5}^{-1/6}$~erg/s. We suggest that the energy liberated during circularization, rather then energy liberated by accretion onto the black hole, powers the observed optical TDE candidates (e.g.A...

  6. "Circularization" vs. Accretion -- What Powers Tidal Disruption Events?

    E-Print Network [OSTI]

    Tsvi Piran; Gilad Svirski; Julian Krolik; Roseanne M. Cheng; Hotaka Shiokawa

    2015-04-07

    A tidal disruption event (TDE) takes place when a star passes near enough to a massive black hole to be disrupted. About half the star's matter is given elliptical trajectories with large apocenter distances, the other half is unbound. To "circularize", i.e., to form an accretion flow, the bound matter must lose a significant amount of energy, with the actual amount depending on the characteristic scale of the flow measured in units of the black hole's gravitational radius ($\\sim 10^{51} (R/1000R_g)^{-1}$~erg). Recent numerical simulations \\citep{Shiokawa+2015} have revealed that the circularization scale is close to the scale of the most-bound initial orbits, $\\sim 10^3 M_{BH,6.5}^{-2/3} R_g \\sim 10^{15} M_{BH,6.5}^{1/3}$~cm from the black hole, and the corresponding circularization energy dissipation rate is $\\sim 10^{44} M_{BH,6.5}^{-1/6}$~erg/s. We suggest that the energy liberated during circularization, rather then energy liberated by accretion onto the black hole, powers the observed optical TDE candidates. The observed rise times, luminosities, temperatures, emission radii, and line widths seen in these TDEs \\citep[e.g.][]{Arcavi+2014} are all more readily explained in terms of heating associated with circularization than in terms of accretion.

  7. Automatic analysis of flow cytometric DNA histograms from irradiated mouse male germ cells

    SciTech Connect (OSTI)

    Lampariello, F.; Mauro, F.; Uccelli, R.; Spano, M.

    1989-01-01

    An automatic procedure for recovering the DNA content distribution of mouse irradiated testis cells from flow cytometric histograms is presented. First, a suitable mathematical model is developed, to represent the pattern of DNA content and fluorescence distribution in the sample. Then a parameter estimation procedure, based on the maximum likelihood approach, is constructed by means of an optimization technique. This procedure has been applied to a set of DNA histograms relative to different doses of 0.4-MeV neutrons and to different time intervals after irradiation. In each case, a good agreement between the measured histograms and the corresponding fits has been obtained. The results indicate that the proposed method for the quantitative analysis of germ cell DNA histograms can be usefully applied to the study of the cytotoxic and mutagenic action of agents of toxicological interest such as ionizing radiations.18 references.

  8. Spectrophotometric determination of uranium(VI) with chlorophosphonazo-mN by flow injection analysis

    SciTech Connect (OSTI)

    Sun, Jun Ying; Chen, Xing Guo; Hu, Zhi De

    1994-07-01

    A sensitive and selective spectrophotometric flow injection analysis (FIA) method with chlorophosphonazo-mN has been developed for the determination of uranium(VI) in standard ore samples. Most interfereing ions are effectively eliminated by the masking reagent diethylenetriaminepentaacetic acid (DTPA). In the U(VI)-chlorophosphonazo-mN system, the maximum absorption wavelength is at 680 nm and Beer`s law is obeyed in the range of 1 to 15 {mu}g {mu}l{sup -1}. The correlation coefficient of the calibration curve is. 0.9998, the sampling frequency is 60{sup -1}, and detection limit for uranium(VI) is 0.5 {mu}g mul{sup -1}.

  9. Multifractal detrended fluctuation analysis of combustion flames in four-burner impinging entrained-flow gasifier

    E-Print Network [OSTI]

    Niu, Miao-Ren; Yan, Zhuo-Yong; Guo, Qing-Hua; Liang, Qin-Feng; Wang, Fu-Chen; Yu, Zun-Hong

    2007-01-01

    On a laboratory-scale testing platform of impinging entrained-flow gasifier with four opposed burners, the flame images for diesel combustion and gasification process were measured with a single charge coupled device (CCD) camera. The two-dimensional multifractal detrended fluctuation analysis was employed to investigate the multifractal nature of the flame images. Sound power-law scaling in the annealed average of detrended fluctuations was unveiled when the order $q>0$ and the multifractal feature of flame images were confirmed. Further analyses identified two multifractal parameters, the minimum and maximum singularity $\\alpha_{\\min}$ and $\\alpha_{\\max}$, serving as characteristic parameters of the multifractal flames. These two characteristic multifractal parameters vary with respect to different experimental conditions.

  10. Multiscale heterogeneity characterization of tidal channel, tidal delta and foreshore facies, Almond Formation outcrops, Rock Springs uplift, Wyoming

    SciTech Connect (OSTI)

    Schatzinger, R.A.; Tomutsa, L.

    1997-08-01

    In order to accurately predict fluid flow within a reservoir, variability in the rock properties at all scales relevant to the specific depositional environment needs to be taken into account. The present work describes rock variability at scales from hundreds of meters (facies level) to millimeters (laminae) based on outcrop studies of the Almond Formation. Tidal channel, tidal delta and foreshore facies were sampled on the eastern flank of the Rock Springs uplift, southeast of Rock Springs, Wyoming. The Almond Fm. was deposited as part of a mesotidal Upper Cretaceous transgressive systems tract within the greater Green River Basin. Bedding style, lithology, lateral extent of beds of bedsets, bed thickness, amount and distribution of depositional clay matrix, bioturbation and grain sorting provide controls on sandstone properties that may vary more than an order of magnitude within and between depositional facies in outcrops of the Almond Formation. These features can be mapped on the scale of an outcrop. The products of diagenesis such as the relative timing of carbonate cement, scale of cemented zones, continuity of cemented zones, selectively leached framework grains, lateral variability of compaction of sedimentary rock fragments, and the resultant pore structure play an equally important, although less predictable role in determining rock property heterogeneity. A knowledge of the spatial distribution of the products of diagenesis such as calcite cement or compaction is critical to modeling variation even within a single facies in the Almond Fin. because diagenesis can enhance or reduce primary (depositional) rock property heterogeneity. Application of outcrop heterogeneity models to the subsurface is greatly hindered by differences in diagenesis between the two settings. The measurements upon which this study is based were performed both on drilled outcrop plugs and on blocks.

  11. Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects

    SciTech Connect (OSTI)

    Spane, Frank A.

    2013-04-29

    Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects

  12. Reference Model #1 - Tidal Energy: Resource Dr. Brian Polagye

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

    constituents, as well as the aharmonic response to these currents induced by local topography and bathymetry. Aharmonic currents are not described by tidal constituents, but are...

  13. First Commercial, Grid-Connected, Hydrokinetic Tidal Energy Project...

    Office of Science (SC) Website

    First Commercial, Grid-Connected, Hydrokinetic Tidal Energy Project in North America Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) SBIR...

  14. Fluid Flow and Thermodynamic Analysis of a Wing Anti-Icing System

    E-Print Network [OSTI]

    is controlled through regulating the hot flow passing a wing anti-icing valve by an automatic control system

  15. Investigation of Tidal Exchange and the Formation of Tidal Vortices at Aransas Pass, Texas, USA 

    E-Print Network [OSTI]

    Whilden, Kerri Ann

    2015-08-11

    Laboratory and field measurements are presented as part of a study of tidal exchange through Aransas Pass, Texas. At the mouth of Aransas Pass, the input of circulation by the ebb tide forces the formation of a starting-jet dipole vortex...

  16. The importance of tidal creek ecosystems Keywords: Estuary; Tidal creek; Pollution

    E-Print Network [OSTI]

    Mallin, Michael

    . They are most abundant along the Atlantic Seaboard from New Jersey to Florida, and along the Gulf Coast). Tidal creeks are especially abundant in low-energy systems such as protected areas behind barrier. As an example, the four southernmost coastal counties in North Carolina (Onslow, Pender, New Hanover

  17. Tidal Energy Test Platform | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-EnhancingEt Al., 2013)Open Energy Information ThreeTianDi GrowthTibagiTidalTest

  18. Stability analysis and design of time-domain acoustic impedance boundary conditions for lined duct with mean flow

    E-Print Network [OSTI]

    Huang, Xun

    Stability analysis and design of time-domain acoustic impedance boundary conditions for lined duct in a lined duct with uniform mean flow, which has important practical interest for noise emission by aero boundary conditions act as closed-loop feedbacks to an overall duct acoustic system. It turns out

  19. Ocean Tidal Dissipation and its Role in Solar System Satellite Evolution

    E-Print Network [OSTI]

    Chen, Erinna

    2013-01-01

    Significant dissipation of tidal energy in the deep ocean2001. Estimates of M 2 tidal energy dissipation from TOPEX/e.g. the ocean kinetic energy and tidal dissipation, using a

  20. Snacktime for Hungry Black Holes: Theoretical Studies of the Tidal Disruption of Stars

    E-Print Network [OSTI]

    Strubbe, Linda Elisabeth

    2011-01-01

    tidal disruption rate as a function of pericenter distance at various energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tidal disruption rate as a function of pericenter distance at various energies2.5: Spectral energy distributions for tidal flares around a

  1. Binary asteroid systems: Tidal end states and estimates of material properties

    E-Print Network [OSTI]

    Taylor, PA; Margot, JL

    2011-01-01

    tidal evolution and then discuss stability limits and energyon tidal evolution. Angular momentum and energy content Theenergy can be dissipated as heat as a result of internal friction due to tidal ?

  2. Environmental Effects of Sediment Transport Alteration and Impacts on Protected Species: Edgartown Tidal Energy Project

    SciTech Connect (OSTI)

    Barrett, Stephen B.; Schlezinger, David, Ph.D; Cowles, Geoff, Ph.D; Hughes, Patricia; Samimy; Roland, I.; and Terray, E, Ph.D.

    2012-12-29

    The Islands of Martha�¢����s Vineyard and Nantucket are separated from the Massachusetts mainland by Vineyard and Nantucket Sounds; water between the two islands flows through Muskeget Channel. The towns of Edgartown (on Martha�¢����s Vineyard) and Nantucket recognize that they are vulnerable to power supply interruptions due to their position at the end of the power grid, and due to sea level rise and other consequences of climate change. The tidal energy flowing through Muskeget Channel has been identified by the Electric Power Research Institute as the strongest tidal resource in Massachusetts waters. The Town of Edgartown proposes to develop an initial 5 MW (nameplate) tidal energy project in Muskeget Channel. The project will consist of 14 tidal turbines with 13 providing electricity to Edgartown and one operated by the University of Massachusetts at Dartmouth for research and development. Each turbine will be 90 feet long and 50 feet high. The electricity will be brought to shore by a submarine cable buried 8 feet below the seabed surface which will landfall in Edgartown either on Chappaquiddack or at Katama. Muskeget Channel is located between Martha�¢����s Vineyard and Nantucket. Its depth ranges between 40 and 160 feet in the deepest portion. It has strong currents where water is transferred between Nantucket Sound and the Atlantic Ocean continental shelf to the south. This makes it a treacherous passage for navigation. Current users of the channel are commercial and recreational fishing, and cruising boats. The US Coast Guard has indicated that the largest vessel passing through the channel is a commercial scallop dragger with a draft of about 10 feet. The tidal resource in the channel has been measured by the University of Massachusetts-Dartmouth and the peak velocity flow is approximately 5 knots. The technology proposed is the helical Gorlov-type turbine positioned with a horizontal axis that is positively buoyant in the water column and held down by anchors. This is the same technology proposed by Ocean Renewable Power Company in the Western Passage and Cobscook Bay near Eastport Maine. The blades rotate in two directions capturing the tides energy both during flood and ebb tides. The turbines will be anchored to the bottom and suspended in the water column. Initial depth of the turbines is expected to be about 25 feet below the surface to avoid impacting navigation while also capturing the strongest currents. The Town of Edgartown was initially granted a Preliminary Permit by the Federal Energy Regulatory Commission (FERC) on March 1, 2008, and has recently received a second permit valid through August 2014. The Preliminary Permit gives Edgartown the exclusive right to apply for a power generation license for power generated from the hydrokinetic energy in the water flowing in this area. Edgartown filed a Draft Pilot License Application with FERC on February 1, 2010 and an Expanded Environmental Notification Form with the Massachusetts Environmental Policy Act (MEPA) Office at the same time. It expects to file a Final License Application in late 2013. Harris Miller Miller & Hanson (HMMH) of Burlington Massachusetts is acting as the Project Manager for the Town of Edgartown and collaborating with other partners of the project including the University of Massachusetts - Dartmouth's Marine Renewable Energy Center and the Massachusetts Clean Energy Center. HMMH was awarded a grant under the Department of Energy's Advanced Water Program to conduct marine science and hydrokinetic site-specific environmental studies for projects actively seeking a FERC License. HMMH, on behalf of the Town, is managing this comprehensive study of the marine environment in Muskeget Channel and potential impacts of the tidal project on indicator species and habitats. The University of Massachusetts School of Marine Science and Technology (SMAST) conducted oceanographic studies of tidal currents, tide level, benthic habit

  3. Lyman Alpha Absorption and Tidal Debris

    E-Print Network [OSTI]

    Simon L. Morris

    1994-09-29

    The origin and evolution of structure in the Universe is one of the major questions occupying astronomers today. An understanding of the Lyalpha absorbers seen in QSO spectra is an important part of this program since such absorbers can be traced back to very high redshifts. Their mere existence places constraints on the physical state of the intergalactic medium. The discovery of Lyalpha absorbers at low redshift allows us to estimate for the first time what fraction of low redshift Lyalpha absorbers are (i) randomly distributed, (ii) distributed like galaxies but not physically associated with luminous objects, (iii) actually part of the halos of luminous galaxies, or (iv) tidal tails within galaxy groups. Results from the sightline to the QSO 3C273 suggest that the majority of the absorbers are not associated with galaxies, but that there is a significant subset that are. The absorbers associated with galaxies may be produced in enormous gaseous disks surrounding normal spiral galaxies, or may be tidal material bound up in small groups of galaxies

  4. ORIGINAL PAPER Predicting Avian Abundance Within and Across Tidal

    E-Print Network [OSTI]

    Kelly, Maggi

    ORIGINAL PAPER Predicting Avian Abundance Within and Across Tidal Marshes Using Fine Scientists 2010 Abstract Tidal marsh monitoring and restoration can benefit from the union of fine developed statistical models with relatively high explanatory power. In each case, models were improved

  5. Virginia Wetlands Report Tools of the Tidal Shoreline

    E-Print Network [OSTI]

    Virginia Wetlands Report Tools of the Tidal Shoreline Management Trade Friday, October 13, 2006) technology with digital aerial photographs and the power of the Internet. They are accessible from desktop Comprehensive Coastal Inventory has produced several GIS tools for the tidal shoreline management trade

  6. Tilted Baroclinic Tidal Vortices MIGUEL CANALS AND GENO PAWLAK

    E-Print Network [OSTI]

    MacCready, Parker

    Tilted Baroclinic Tidal Vortices MIGUEL CANALS AND GENO PAWLAK Department of Ocean and Resources coherence. It is suggested that this may lead to a conversion of potential energy into kinetic energy. 1 mixing of coastal waters (Mul- ler and Garrett 2003). Of particular importance is the tidally driven case

  7. Tidal Conversion at a Submarine Ridge FRANOIS PTRLIS

    E-Print Network [OSTI]

    Young, William R.

    ). Satellite altimetry has shown deep-sea tidal energy losses concentrated at submarine ridges and island arcsTidal Conversion at a Submarine Ridge FRANÇOIS PÉTRÉLIS Laboratoire de Physique Statistique, Ecole received 30 July 2003, in final form 20 January 2004) ABSTRACT The radiative flux of internal wave energy

  8. CONTROL ID: 1187959 TITLE: Climate destabilization on tidally locked exoplanets

    E-Print Network [OSTI]

    CONTROL ID: 1187959 TITLE: Climate destabilization on tidally locked exoplanets PRESENTATION TYPE-zone rocky planets, should be tidally locked. We will discuss two different feedbacks that can destabilize cause a runaway climate shift. We use an idealized energy balance model to illustrate the scope

  9. Real Time Flow Estimation in Channel Networks using Lagrangian Data Qingfang Wu

    E-Print Network [OSTI]

    - formation about tidal forcing and salinity transport in the bays and channels of the Delta. Reliable flow in the Delta in a real-time mode, without dependence on historical data. Lagrangian data is obtained when a distributed network of channels, subject to quasi-periodic tidal forcing, in the Sacramento-San Joaquin River

  10. Two-Phase Void Drift Phenomena in a 2 x 3 Rod Bundle: Flow Redistribution Data and Their Analysis

    SciTech Connect (OSTI)

    Sadatomi, Michio; Kawahara, Akimaro; Kuno, Tsukasa; Kano, Keiko [Kumamoto University (Japan)

    2005-10-15

    To improve a void drift model used in a subchannel analysis, new experimental data are obtained for air-water two-phase flows in a vertical 2 x 3 rod channel consisting of six subchannels simulating a square array boiling water reactor fuel rod bundle. The data include the axial redistributions of flow rates of both phases and void fraction in the respective subchannels. By fitting the above data with the Lahey and Moody void settling model, we have determined a void diffusion coefficient in their model. It is found that the void diffusion coefficient for slug, churn, and annular flows could be well correlated in terms of a turbulent Peclet number developed in our previous study. Furthermore, a subchannel analysis code based on a two-fluid model proposed in our previous study is examined against the present data. In the code, the void settling model is incorporated with usual conservation equations of mass and momentum. From the examination, it is found that the subchannel analysis code can predict well the data on subchannel flow and void fraction for the 2 x 3 rod channel if appropriate correlations are adopted to evaluate wall and interfacial friction forces needed in the two-fluid model.

  11. Tidal deformation of a slowly rotating material body. External metric

    E-Print Network [OSTI]

    Philippe Landry; Eric Poisson

    2015-07-31

    We construct the external metric of a slowly rotating, tidally deformed material body in general relativity. The tidal forces acting on the body are assumed to be weak and to vary slowly with time, and the metric is obtained as a perturbation of a background metric that describes the external geometry of an isolated, slowly rotating body. The tidal environment is generic and characterized by two symmetric-tracefree tidal moments E_{ab} and B_{ab}, and the body is characterized by its mass M, its radius R, and a dimensionless angular-momentum vector \\chi^a new quantities, which we designate as rotational-tidal Love numbers. All these Love numbers are gauge invariant in the usual sense of perturbation theory, and all vanish when the body is a black hole.

  12. Confusion around the tidal force and the centrifugal force

    E-Print Network [OSTI]

    Matsuda, Takuya; Boffin, Henri M J

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  13. 1992 Columbia River Salmon Flow Measures Options Analysis/EIS : Appendices.

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and one private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described. The document concludes with an evaluation of the potential effects that could result from implementing proposed actions. The conclusions are based on evaluation of existing data, utilization of numerical models, and application of logical inference. This volume contains the appendices.

  14. A Database and Meta-Analysis of Ecological Responses to Flow in the South Atlantic Region

    SciTech Connect (OSTI)

    McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University (Virginia Tech); Davis, Dr, Mary [Southeastern Aquatic Resources Partnership; Kauffman, John [John Kauffman LLC.

    2013-01-01

    Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitative relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we utilized ecological gains or losses, where each represents a benefit or reduction to ecosystem services, respectively. Variables explained 49% of the variation in ecological gains and losses for all ecological groups combined. Altogether, our results suggested that the source of flow change and the ecological group of interest played primary roles in determining the direction and magnitude of ecological responses. Furthermore, our results suggest that developing broadly generalized relationships between ecology and changes in flow at a regional scale is unlikely unless relationships are placed within meaningful contexts, such as environmental flow components or by geomorphic setting.

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

    SciTech Connect (OSTI)

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

    2011-10-01

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

  16. Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control

    SciTech Connect (OSTI)

    Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y.

    2006-07-01

    The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

  17. Purged window apparatus. [On-line spectroscopic analysis of gas flow systems

    DOE Patents [OSTI]

    Ballard, E.O.

    1982-04-05

    A purged window apparatus is described which utilizes tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube thereby preventing backstreaming of flowing gases under investigation in a chamber to which a plurality of similar purged apparatus is attached with the consequent result that spectroscopic analyses can be undertaken for lengthy periods without the necessity of interrupting the flow for cleaning or replacing the windows due to contamination.

  18. A flood-based information flow analysis and network minimization method for gene regulatory networks

    E-Print Network [OSTI]

    Pavlogiannis, Andreas; Mozhayskiy, Vadim; Tagkopoulos, Ilias

    2013-01-01

    as: Pavlogiannis et al. : A flood-based information flowRESEARCH ARTICLE Open Access A flood-based information flowlevels. Keywords: Network flood, Network flux, Information

  19. Three-dimensional analysis of variably-saturated flow and solute ...

    E-Print Network [OSTI]

    2003-07-16

    1989). Recent field studies have shown ..... any water and thus reduce the area available for matrix flow across the fracture. We use ...... enhanced oil recovery.

  20. A stochastic analysis of steady state two-phase flow in heterogeneous media

    E-Print Network [OSTI]

    Lu, Zhiming

    and soil pore size distribution. A stochastic numerical model for steady state water-oil flow in a random these expansions of Y(x), b(x) and dependent pressures, the steady state water-oil flow equations and corresponding size distribution b(x) are assumed to be Gaussian random functions with a separable exponential

  1. Disc formation from stellar tidal disruptions

    E-Print Network [OSTI]

    Bonnerot, Clément; Lodato, Giuseppe; Price, Daniel J

    2015-01-01

    The potential of tidal disruption of stars to probe otherwise quiescent supermassive black holes cannot be exploited, if their dynamics is not fully understood. So far, the observational appearance of these events has been commonly derived from analytical extrapolations of the debris dynamical properties just after the stellar disruption. In this paper, we perform hydrodynamical simulations of stars in highly eccentric orbits, that follow the stellar debris after disruption and investigate their ultimate fate. We demonstrate that gas debris circularize on an orbital timescale because relativistic apsidal precession causes the stream to self-cross. The higher the eccentricity and/or the deeper the encounter, the faster is the circularization. If the internal energy deposited by shocks during stream self-interaction is readily radiated, the gas forms a narrow ring at the circularization radius. It will then proceed to accrete viscously at a super-Eddington rate, puffing up under radiation pressure. If instead c...

  2. Uncovering CDM halo substructure with tidal streams

    E-Print Network [OSTI]

    R. A. Ibata; G. F. Lewis; M. J. Irwin

    2001-10-31

    Models for the formation and growth of structure in a cold dark matter dominated universe predict that galaxy halos should contain significant substructure. Studies of the Milky Way, however, have yet to identify the expected few hundred sub-halos with masses greater than about 10^6 Msun. Here we propose a test for the presence of sub-halos in the halos of galaxies. We show that the structure of the tidal tails of ancient globular clusters is very sensitive to heating by repeated close encounters with the massive dark sub-halos. We discuss the detection of such an effect in the context of the next generation of astrometric missions, and conclude that it should be easily detectable with the GAIA dataset. The finding of a single extended cold stellar stream from a globular cluster would support alternative theories, such as self-interacting dark matter, that give rise to smoother halos.

  3. Tidal Downsizing model. I. Numerical methods: saving giant planets from tidal disruptions

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2014-01-01

    Tidal Downsizing (TD) is a recently developed planet formation theory that supplements the classical Gravitational disc Instability (GI) model with planet migration inward and tidal disruptions of GI fragments in the inner regions of the disc. Numerical methods for a detailed population synthesis of TD planets are presented here. As an example application, the conditions under which GI fragments collapse faster than they migrate into the inner $a\\sim$ few AU disc are considered. It is found that most gas fragments are tidally or thermally disrupted unless (a) their opacity is $\\sim 3$ orders of magnitude less than the interstellar dust opacity at metallicities typical of the observed giant planets, or (b) the opacity is high but the fragments accrete large dust grains (pebbles) from the disc. Case (a) models produce very low mass solid cores ($M_{\\rm core} < 0.1$ Earth masses) and follow a negative correlation of giant planet frequency with host star metallicity. In contrast, case (b) models produce massiv...

  4. The variation of tidal dissipation in the convective envelope of low-mass stars along their evolution

    E-Print Network [OSTI]

    Mathis, S

    2015-01-01

    Since 1995, more than 1500 exoplanets have been discovered around a large diversity of host stars (from M- to A-type stars). Tidal dissipation in stellar convective envelopes is a key actor that shapes the orbital architecture of short-period systems. Our objective is to understand and evaluate how tidal dissipation in the convective envelope of low-mass stars (from M to F types) depends on their mass, evolutionary stage and rotation. Using a simplified two-layer assumption, we compute analytically the frequency-averaged tidal dissipation in their convective envelope. This dissipation is due to the conversion into heat of the kinetic energy of tidal non wave-like/equilibrium flow and inertial waves because of the viscous friction applied by turbulent convection. Using grids of stellar models allows us to study the variation of the dissipation as a function of stellar mass and age on the Pre-Main-Sequence and on the Main-Sequence for stars with masses spanning from $0.4$ to $1.4M_{\\odot}$. As shown by observat...

  5. Comparing the escape dynamics in tidally limited star cluster models

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2015-08-21

    The aim of this work is to compare the orbital dynamics in three different models describing the properties of a star cluster rotating around its parent galaxy in a circular orbit. In particular, we use the isochrone and the Hernquist potentials to model the spherically symmetric star cluster and we compare our results with the corresponding ones of a previous work in which the Plummer model was applied for the same purpose. Our analysis takes place both in the configuration $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the tidally limited star cluster. We restrict our investigation into two dimensions and we conduct a thorough numerical analysis distinguishing between ordered and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels above the critical escape energy. It is of particular interest to determine the escape basins towards the two exit channels (near the Lagrangian points $L_1$ and $L_2$) and relate them with the corresponding escape times of the orbits.

  6. Comparing the escape dynamics in tidally limited star cluster models

    E-Print Network [OSTI]

    Zotos, Euaggelos E

    2015-01-01

    The aim of this work is to compare the orbital dynamics in three different models describing the properties of a star cluster rotating around its parent galaxy in a circular orbit. In particular, we use the isochrone and the Hernquist potentials to model the spherically symmetric star cluster and we compare our results with the corresponding ones of a previous work in which the Plummer model was applied for the same purpose. Our analysis takes place both in the configuration $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the tidally limited star cluster. We restrict our investigation into two dimensions and we conduct a thorough numerical analysis distinguishing between ordered and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels above the critical escape energy. It is of particular interest to determine the escape basins towards the two exit channels (n...

  7. Measurement of Tidal Form Drag Using Seafloor Pressure Sensors SALLY J. WARNER AND PARKER MACCREADY

    E-Print Network [OSTI]

    MacCready, Parker

    tides. The tidally averaged power removed from the tidal currents by form drag was 0.2 W m22 , whichMeasurement of Tidal Form Drag Using Seafloor Pressure Sensors SALLY J. WARNER AND PARKER MACCREADY the tidal form drag on a sloping ridge in 200 m of water that forms a 1-km headland at the surface in Puget

  8. Lagrangian analysis of a tidal plume Initial Expansion of the Columbia River Tidal Plume

    E-Print Network [OSTI]

    Jay, David

    numerical model (with five mixing formulations) are tested. Model results are compared to SAR images and vessel radar data to verify that the predicted fron- tal properties are realistic. The models show, and it is important to include the horizontal gradient in F as well as surface slope in the pressure gradient driving

  9. Rheo-PIV Analysis of the Yielding and Flow of Model Waxy Crude Oils

    E-Print Network [OSTI]

    Dimitriou, Christopher J.

    Waxes are a commonly encountered precipitate that can result in the gelation of crude oils and cessation of flow in pipelines. In this work, we develop a model wax–oil system that exhibits rheological behavior similar to ...

  10. Improving Surge Flow Irrigation Efficiency Based on Analysis of Infiltration and Hydrodynamic Effects 

    E-Print Network [OSTI]

    Smerdon, Ernest T.; Blair, Allie W.

    1985-01-01

    varying nonlinear infiltration. Each partitioned section also contained an electronic water depth sensor. All 15 water depth sensors are connected to a real time data acquisition system which relays depth of flow information to the computer simulating...

  11. Statistical Analysis of Microgravity Two-Phase Slug Flow via the Drift Flux Model 

    E-Print Network [OSTI]

    Larsen, Benjamin A

    2014-05-01

    of microgravity two-phase flow data difficult. Multiple researchers have postulated the microgravity drift flux model parameters to predict void fraction, however, these methods were initially developed with no consideration given to a microgravity environment...

  12. Effects of non-Darcy flow on pressure buildup analysis of hydraulically fractured gas reservoirs 

    E-Print Network [OSTI]

    Alvarez Vera, Cesar

    2001-01-01

    Conventional well-testing techniques are commonly used to evaluate pressure transient tests of hydraulically fractured wells to estimate values such as formation permeability, fracture length, and fracture conductivity. When non-Darcy flow occurs...

  13. Analysis of multiphase fluid flows via high speed and synthetic aperture three dimensional imaging

    E-Print Network [OSTI]

    Scharfman, Barry Ethan

    2012-01-01

    Spray flows are a difficult problem within the realm of fluid mechanics because of the complicated interfacial physics involved. Complete models of sprays having even the simplest geometries continue to elude researchers ...

  14. Momentum and mass transport by coherent structures in a shallow vegetated shear flow

    E-Print Network [OSTI]

    White, Brian L., 1975-

    2006-01-01

    In many aquatic systems, from tidal creeks with fringing mangroves to rivers and associated floodplains, there exists an interface between dense vegetation and a high conveyance channel. A shear flow develops across this ...

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

    SciTech Connect (OSTI)

    Ralph Showalter; Malgorzata Peszynska

    2012-07-03

    The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

  16. ACFAC: a cash flow analysis code for estimating product price from an industrial operation

    SciTech Connect (OSTI)

    Delene, J.G.

    1980-04-01

    A computer code is presented which uses a discountted cash flow methodology to obtain an average product price for an industtrial process. The general discounted cash flow method is discussed. Special code options include multiple treatments of interest during construction and other preoperational costs, investment tax credits, and different methods for tax depreciation of capital assets. Two options for allocating the cost of plant decommissioning are available. The FORTRAN code listing and the computer output for a sample problem are included.

  17. Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: I. Along-channel Water Level Variations, Pacific Ocean to Bonneville Dam

    SciTech Connect (OSTI)

    Jay, D. A.; Leffler, K.; Diefenderfer, Heida L.; Borde, Amy B.

    2014-06-07

    This two-part paper provides comprehensive time and frequency domain analyses and models of along-channel water level variations in the 234km-long Lower Columbia River and Estuary (LCRE) and documents the response of floodplain wetlands thereto. In Part I, power spectra, continuous wavelet transforms, and harmonic analyses are used to understand the influences of tides, river flow, upwelling and downwelling, and hydropower operations ("power-peaking") on the water level regime. Estuarine water levels are influenced primarily by astronomical tides and coastal processes, and secondarily by river flow. The importance of coastal and tidal influences decreases in the landward direction, and water levels are increasingly controlled by river flow variations at periods from ?1day to years. Water level records are only slightly non-stationary near the ocean, but become increasingly irregular upriver. Although astronomically forced tidal constituents decrease above the estuary, tidal fortnightly and overtide variations increase for 80-200km landward, both relative to major tidal constituents and in absolute terms.

  18. Numerical and Experimental Investigation of Tidal Current Energy Extraction 

    E-Print Network [OSTI]

    Sun, Xiaojing

    2008-01-01

    Numerical and experimental investigations of tidal current energy extraction have been conducted in this study. A laboratory-scale water flume was simulated using commercial computational fluid dynamics (CFD) code FLUENT. ...

  19. Geomorphic structure of tidal hydrodynamics in salt marsh creeks

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    .1029/2007WR006289. 1. Introduction [2] Salt marshes are important transitional areas between terrestrial providing preferen- tial pathways for marsh flooding and drainage during the tidal cycle. Because

  20. A Lagrangian analysis of advection-diffusion equation for a three dimensional chaotic flow

    SciTech Connect (OSTI)

    Tang, X.Z. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Boozer, A.H. [Department of Applied Physics, Columbia University, New York, New York 10027 (United States)] [Department of Applied Physics, Columbia University, New York, New York 10027 (United States); [Max-Planck Institut fuer Plasmaphysik, Garching (Germany)

    1999-06-01

    The advection-diffusion equation is studied via a global Lagrangian coordinate transformation. The metric tensor of the Lagrangian coordinates couples the dynamical system theory rigorously into the solution of this class of partial differential equations. If the flow has chaotic streamlines, the diffusion will dominate the solution at a critical time, which scales logarithmically with the diffusivity. The subsequent rapid diffusive relaxation is completed on the order of a few Lyapunov times, and it becomes more anisotropic the smaller the diffusivity. The local Lyapunov time of the flow is the inverse of the finite time Lyapunov exponent. A finite time Lyapunov exponent can be expressed in terms of two convergence functions which are responsible for the spatio-temporal complexity of both the advective and diffusive transports. This complexity gives a new class of diffusion barrier in the chaotic region and a fractal-like behavior in both space and time. In an integrable flow with shear, there also exist fast and slow diffusion. But unlike that in a chaotic flow, a large gradient of the scalar field across the KAM surfaces can be maintained since the fast diffusion in an integrable flow is strictly confined within the KAM surfaces. {copyright} {ital 1999 American Institute of Physics.}

  1. Sandia Energy - Tidal Energy Resource Assessment in the East River Tidal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochasticunique wind(CREW)Tidal

  2. Linear and nonlinear stability analysis for two-dimensional ideal magnetohydrodynamics with incompressible flows

    SciTech Connect (OSTI)

    Khater, A.H.; Moawad, S.M.; Callebaut, D.K. [Department of Mathematics, Faculty of Science, Cairo University, Beni-Suef (Egypt); Departement Natuurkunde, Campus Drie Eiken, Universiteit Antwerpen - UA, B-2610 Antwerpen (Belgium)

    2005-01-01

    The equilibrium and Lyapunov stability properties for two-dimensional ideal magnetohydrodynamic (MHD) plasmas with incompressible and homogeneous (i.e., constant density) flows are investigated. In the unperturbed steady state, both the velocity and magnetic field are nonzero and have three components in a Cartesian coordinate system with translational symmetry (i.e., one ignorable spatial coordinate). It is proved that (a) the solutions of the ideal MHD steady state equations with incompressible and homogeneous flows in the plane are also valid for equilibria with the axial velocity component being a free flux function and the axial magnetic field component being a constant (b) the conditions of linearized Lyapunov stability for these MHD flows in the planar case (in which the fields have only two components) are also valid for symmetric equilibria that have a nonplanar velocity field component as well as a nonplanar magnetic field component. On using the method of convexity estimates, nonlinear stability conditions are established.

  3. A Bright Year for Tidal Disruptions?

    E-Print Network [OSTI]

    Metzger, Brian D

    2015-01-01

    When a star is tidally disrupted by a supermassive black hole (BH), roughly half of its mass falls back to the BH at super-Eddington rates. Being tenuously gravitationally bound and unable to cool radiatively, only a small fraction f_in few 1e4 K, converting the emission to optical/near-UV wavelengths where photons more readily escape due to the lower opacity. This can explain the unexpectedly low and temporally constant effective temperatures of optically-discovered TDE flares. For BHs with relatively high masses M_BH > 1e7 M_sun the ejecta can become ionized at an earlier stage, or for a wider range of viewing angles, producing a TDE flare which is instead dominated by thermal X-ray emission. We predict total radiated energies consistent with those of observed TDE flares, and ejecta velocities that agree with the measured emission line widths. The peak optical luminosity for M_BH wind, possibly contributing to the unexpected dearth of o...

  4. Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data

    SciTech Connect (OSTI)

    Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

    1990-05-01

    In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data.

  5. Perturbative analysis of sheared flow Kelvin-Helmholtz instability in a weakly relativistic magnetized electron fluid

    SciTech Connect (OSTI)

    Sundar, Sita; Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)

    2012-05-15

    In the interaction of intense lasers with matter/plasma, energetic electrons having relativistic energies get created. These energetic electrons can often have sheared flow profiles as they propagate through the plasma medium. In an earlier study [Phys. Plasmas 17, 022101 (2010)], it was shown that a relativistic sheared electron flow modifies the growth rate and threshold condition of the conventional Kelvin-Helmholtz instability. A perturbative analytic treatment for the case of weakly relativistic regime has been provided here. It provides good agreement with the numerical results obtained earlier.

  6. Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems

    E-Print Network [OSTI]

    LaRocca, Sarah; Hassel, Henrik; Guikema, Seth

    2013-01-01

    Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist which can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. Thus in this paper, we suggest a classification of these models, which span from simple topologically-oriented models to advanced physical flow-based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this pa...

  7. A Novel Power Flow Method for Long Term Frequency Stability Analysis 

    E-Print Network [OSTI]

    Yan, Wenjin

    2013-05-06

    This thesis presents a novel approach for a power system to find a practical power flow solution when all the generators in the system have hit their real power output limits, such as some generator units shutting down or load outages. The approach...

  8. Characterizing Shared Memory Multiprocessor Benchmarks for Future Chip Multiprocessor Architectures Using Instruction Flow Analysis 

    E-Print Network [OSTI]

    Jagielski, Philip

    2011-08-08

    ., 1990. [6] D. D. Gajski, D. A. Padua, D. J. Kuck, and R. H. Kuhn, ?A second opinion on data flow machines and languages,? in Computer, 1982. [7] Charles L. Seitz, ?The cosmic cube,? in Communications of the ACM, 1985. [8] Mark S. Papamarcos and Janak...

  9. Dynamic Pressure Improvements to Closed-Circuit Wind Tunnels with Flow Quality Analysis 

    E-Print Network [OSTI]

    Herring, Alexander

    2015-03-31

    Experiment Station Low-Speed Wind Tunnel (LSWT) was limited through available power to a dynamic pressure of 120 psf. The addition of a higher power motor, construction of a new, smaller test section, diffuser liners to prevent flow separation, and increased...

  10. Conditional moment analysis of steady state unsaturated flow in bounded, randomly heterogeneous soils

    E-Print Network [OSTI]

    Tartakovsky, Daniel M.

    soils Zhiming Lu and Shlomo P. Neuman Department of Hydrology and Water Resources, University of Arizona 26 April 2002. [1] We consider steady state unsaturated flow in bounded, randomly heterogeneous soils that the solution may remain asymptotic for values of sY 2 as large as 2. INDEX TERMS: 1866 Hydrology: Soil moisture

  11. An analysis of flow-simulation scales and seismic response P. L. Stoffa*

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    -gas reservoir during production. Numerical experiments show that saturation fronts can be effectively tracked that saturations are the key factor for tracking changes during production for an oil-gas reservoir. The reservoir, the question which scales flow simulations need to resolve to accurately capture reservoir changes during

  12. RESEARCH PAPER Simulation-based analysis of flow due to traveling-plane-wave

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    : 28 March 2007 Ó Springer-Verlag 2007 Abstract One of the propulsion mechanisms of micro- organisms flows with mechanical micropumps remains somewhat a challenge. Propulsion mechanisms of microorganisms be placed in a channel and actuated for pumping of the fluid by means of introducing a series of traveling

  13. Wavelet analysis study of microbubble drag reduction in a boundary channel flow 

    E-Print Network [OSTI]

    Zhen, Ling

    2006-04-12

    components in streamwise-near-wall normal plane of a turbulent channel flow at Reynolds number of 5128 based on the half height of the channel were measured. The influence of the presence of microbubbles in the boundary layer was assessed and compared...

  14. A Network Analysis of Food Flows within the United States of Xiaowen Lin,

    E-Print Network [OSTI]

    Konar, Megan

    insight into trade network scaling and proxy free trade and equitable network architectures. 1 to the Commerce Clause of the U.S. Constitution), thereby proxying a free trade setting. Studying the network under free trade situations. Third, flows of food within the USA serve as a null model for trade equity

  15. Determination of Nitrogen by Flow Injection Analysis in Environmental and Wastewaters

    SciTech Connect (OSTI)

    Straw, K.A.

    1999-03-01

    In summary, three generations of Lachat FIA systems have been used in the laboratory over a period of 13 yrs, running, in addition to the 4 N methods, Cr{sup +6}, SiO{sub 2}, Fluoride by ISE. Overall flow injection systems have been versatile and reliable and a good choice in the lab for analyzing a wide variety of samples quickly.

  16. A flood-based information flow analysis and network minimization method for gene regulatory networks

    E-Print Network [OSTI]

    Pavlogiannis, Andreas; Mozhayskiy, Vadim; Tagkopoulos, Ilias

    2013-01-01

    networks for functional analysis [13], shortest path algorithms for biological interaction paths [14,15], application of Petri-

  17. Flow cytometric analysis of expression of interleukin-2 receptor beta chain (p70-75) on various leukemic cells

    SciTech Connect (OSTI)

    Hoshino, S.; Oshimi, K.; Tsudo, M.; Miyasaka, M.; Teramura, M.; Masuda, M.; Motoji, T.; Mizoguchi, H. )

    1990-08-15

    We analyzed the expression of the interleukin-2 receptor (IL-2R) beta chain (p70-75) on various leukemic cells from 44 patients by flow cytometric analysis using the IL-2R beta chain-specific monoclonal antibody, designated Mik-beta 1. Flow cytometric analysis demonstrated the expression of the IL-2R beta chain on granular lymphocytes (GLs) from all eight patients with granular lymphocyte proliferative disorders (GLPDs), on adult T-cell leukemia (ATL) cells from all three patients with ATL, and on T-cell acute lymphoblastic leukemia (T-ALL) cells from one of three patients with T-ALL. Although GLs from all the GLPD patients expressed the IL-2R beta chain alone and not the IL-2R alpha chain (Tac-antigen: p55), ATL and T-ALL cells expressing the beta chain coexpressed the alpha chain. In two of seven patients with common ALL (cALL) and in both patients with B-cell chronic lymphocytic leukemia, the leukemic cells expressed the alpha chain alone. Neither the alpha chain nor the beta chain was expressed on leukemic cells from the remaining 28 patients, including all 18 patients with acute nonlymphocytic leukemia, five of seven patients with cALL, all three patients with multiple myeloma, and two of three patients with T-ALL. These results indicate that three different forms of IL-2R chain expression exist on leukemic cells: the alpha chain alone; the beta chain alone; and both the alpha and beta chains. To examine whether the results obtained by flow cytometric analysis actually reflect functional aspects of the expressed IL-2Rs, we studied the specific binding of 125I-labeled IL-2 (125I-IL-2) to leukemic cells in 18 of the 44 patients. In addition, we performed 125I-IL-2 crosslinking studies in seven patients. The results of IL-2R expression of both 125I-IL-2 binding assay and crosslinking studies were in agreement with those obtained by flow cytometric analysis.

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

    SciTech Connect (OSTI)

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

    2009-01-01

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

  19. Turbulent Flow Analysis and Coherent Structure Identification in Experimental Models with Complex Geometries 

    E-Print Network [OSTI]

    Amini, Noushin

    2012-02-14

    applying two different experimental methods. The first study involves the investigation of turbulent impinging jets through a staggered array of rods with or without crossflow. Such flows are crucial in various engineering disciplines. This experiment... ................................................................................................... 47 II.3.1. Time-Averaged Velocity Fields ................................................ 48 II.3.1.1. Single Impinging Jet in the Corner of Mid-Plane ...... 48 II.3.1.2. Single Impinging Jet in the Middle of the Measurement Plane...

  20. Poiseuille flow past a nanoscale cylinder in a slit channel: Lubrication theory versus molecular dynamics analysis

    E-Print Network [OSTI]

    Amir M. Rahmani; Yang Shao; Mehlam Jupiterwala; Carlos E. Colosqui

    2015-04-13

    Plane Poiseuille flow past a nanoscale cylinder that is arbitrarily confined (i.e., symmetrically or asymmetrically confined) in a slit channel is studied via hydrodynamic lubrication theory and molecular dynamics simulations, considering cases where the cylinder remains static or undergoes thermal motion. Lubrication theory predictions for the drag force and volumetric flow rate are in close agreement with molecular dynamics simulations of flows having molecularly thin lubrication gaps, despite the presence of significant structural forces induced by the crystalline structure of the modeled solid. While the maximum drag force is observed in symmetric confinement, i.e., when the cylinder is equidistant from both channel walls, the drag decays significantly as the cylinder moves away from the channel centerline and approaches a wall. Hence, significant reductions in the mean drag force on the cylinder and hydraulic resistance of the channel can be observed when thermal motion induces random off-center displacements. Analytical expressions and numerical results in this work provide useful insights into the hydrodynamics of colloidal solids and macromolecules in confinement.

  1. Analysis of Granular Flow in a Pebble-Bed Nuclear Reactor

    E-Print Network [OSTI]

    Chris H. Rycroft; Gary S. Grest; James W. Landry; Martin Z. Bazant

    2006-02-16

    Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a major impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30 degrees or 60 degrees. We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.

  2. Linear analysis on the growth of non-spherical perturbations in supersonic accretion flows

    SciTech Connect (OSTI)

    Takahashi, Kazuya; Yamada, Shoichi, E-mail: ktakahashi@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku 169-8555 (Japan)

    2014-10-20

    We analyzed the growth of non-spherical perturbations in supersonic accretion flows. We have in mind an application to the post-bounce phase of core-collapse supernovae (CCSNe). Such non-spherical perturbations have been suggested by a series of papers by Arnett, who has numerically investigated violent convections in the outer layers of pre-collapse stars. Moreover, Couch and Ott demonstrated in their numerical simulations that such perturbations may lead to a successful supernova even for a progenitor that fails to explode without fluctuations. This study investigated the linear growth of perturbations during the infall onto a stalled shock wave. The linearized equations are solved as an initial and boundary value problem with the use of a Laplace transform. The background is a Bondi accretion flow whose parameters are chosen to mimic the 15 M {sub ?} progenitor model by Woosley and Heger, which is supposed to be a typical progenitor of CCSNe. We found that the perturbations that are given at a large radius grow as they flow down to the shock radius; the density perturbations can be amplified by a factor of 30, for example. We analytically show that the growth rate is proportional to l, the index of the spherical harmonics. We also found that the perturbations oscillate in time with frequencies that are similar to those of the standing accretion shock instability. This may have an implication for shock revival in CCSNe, which will be investigated in our forthcoming paper in more detail.

  3. General relativistic tidal work for Papapetrou, Weinberg and Goldberg pseudotensors

    E-Print Network [OSTI]

    Lau Loi So

    2015-05-18

    In 1998 Thorne claimed that all pseudotensors give the same tidal work as the Newtonian theory. In 1999, Purdue used the Landau-Lifshitz pseudotensor to calculate the tidal heating and the result matched with the Newtonian gravity. Soon after in 2001, Favata employed the same method to examine the Einstein, Bergmann-Thomson and M{\\o}ller pseudotensors, all of them give the same result as Purdue did. Inspired by the work of Purdue and Favata, for the completeness, here we manipulate the tidal work for Papapetrou, Weinberg and Goldberg pseudotensors. We obtained the same tidal work as Purdue achieved. In addition, we emphasize that a suitable gravitational energy-momentum pseudotensor requires fulfill the inside matter condition and all of the classical pseudotensors pass this test except M$\\o$ller. Moreover, we constructed a general pseudotesnor which is modified by 13 linear artificial higher order terms combination with Einstein pseudotensor. We find that the result agrees with Thorne's prediction, i.e., relativistic tidal work is pseudotensor independent.

  4. NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

    SciTech Connect (OSTI)

    Smith, Brennan T; Neary, Vincent S; Stewart, Kevin M

    2012-01-01

    A geodatabase of tidal constituents is developed to present the regional assessment of tidal stream power resource in the USA. Tidal currents are numerically modeled with the Regional Ocean Modeling System (ROMS) and calibrated with the available measurements of tidal current speeds and water level surfaces. The performance of the numerical model in predicting the tidal currents and water levels is assessed by an independent validation. The geodatabase is published on a public domain via a spatial database engine with interactive tools to select, query and download the data. Regions with the maximum average kinetic power density exceeding 500 W/m2 (corresponding to a current speed of ~1 m/s), total surface area larger than 0.5 km2 and depth greater than 5 m are defined as hotspots and documented. The regional assessment indicates that the state of Alaska (AK) has the largest number of locations with considerably high kinetic power density, followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL).

  5. Variability in tidal disruption events: gravitationally unstable streams

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01

    We present simulations of the tidal disruption of a solar mass star by a $10^6M_{\\odot}$ black hole. These, for the first time, cover the full time evolution of the tidal disruption event, starting well before the initial encounter and continuing until more than 90% of the bound material has returned to the vicinity of the hole. Our results are compared to the analytical prediction for the rate at which tidally-stripped gas falls back. We find that, for our chosen parameters, the overall scaling of the fallback rate, $\\dot{M}_{\\rm{fb}}$, closely follows the canonical $t^{-5/3}$ power-law. However, our simulations also show that the self-gravity of the tidal stream, which dominates the tidal gravity of the hole at large distances, causes some of the debris to recollapse into bound fragments before returning to the hole. This causes $\\dot{M}_{\\rm{fb}}$ to vary significantly around the $t^{-5/3}$ average. We discuss the implications of our findings in the context of the event Swift J1644+57.

  6. Modeling and analysis of the movement of fluid-fluid interfaces in porous media coupled with turbulent free flow

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    allows the coupling of a laminar single-phase free flow and a two-phase porous-medium flow under non be necessary Coupling Situation coupling exists for laminar free flow (Mostaf et al. 2011) boundary layer DuMux in use for Darcy flow and laminar Stokes flow no RANS solver in DuMux or DUNE PDELab Open

  7. In situ stress, fracture, and fluid flow analysis in Well 38C...

    Open Energy Info (EERE)

    wellbore image data, natural fracture characterization, and wellbore failure analysis. A hydraulic fracturing stress test at 3,703 feet TVD was used to constrain a normal faulting...

  8. IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C...

    Open Energy Info (EERE)

    wellbore image data, natural fracture characterization, and wellbore failure analysis. A hydraulic fracturing stress test at 3,703 feet TVD was used to constrain a normal faulting...

  9. Analysis of Breathing Air Flow Patterns in Thermal Imaging Department of Computer Science

    E-Print Network [OSTI]

    biometric. I. INTRODUCTION Many respiratory diseases like sleep apnea syndrome and bronchial asthma of pathophysiolog- ical causes, pattern analysis reveals that individual breathing patterns are not random [3

  10. To cite this version : Rigo-Mariani, Rmy and Sareni, Bruno and Roboam, Xavier Fast Power Flow Scheduling and Sensitivity Analysis for Sizing a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for optimal dispatching of power flows in a microgrid with storage. The investigated approach is based Scheduling and Sensitivity Analysis for Sizing a Microgrid with Storage. (2014) In: 11th International ANALYSIS FOR SIZING A MICROGRID WITH STORAGE R. Rigo-Mariani1 , B. Sareni1 , X. Roboam1 1. Université de

  11. TIDAL DISRUPTION FLARES: THE ACCRETION DISK PHASE

    SciTech Connect (OSTI)

    Montesinos Armijo, Matias; De Freitas Pacheco, Jose A. [Observatoire de la Cote d'Azur, Laboratoire Cassiopee, Universite de Nice Sophia-Antipolis Bd de l'Observatoire, BP 4229, 06304 Nice Cedex 4 (France)

    2011-08-01

    The evolution of an accretion disk, formed as a consequence of the disruption of a star by a black hole, is followed by solving numerically hydrodynamic equations. The present investigation aims to study the dependence of resulting light curves on dynamical and physical properties of such a transient disk during its existence. One of the main results derived from our simulations is that blackbody fits of X-ray data tend to overestimate the true mean disk temperature. In fact, the temperature derived from blackbody fits should be identified with the color X-ray temperature rather than the average value derived from the true temperature distribution along the disk. The time interval between the beginning of the circularization of the bound debris and the beginning of the accretion process by the black hole is determined by the viscous (or accretion) timescale, which also fixes the rising part of the resulting light curve. The luminosity peak coincides with the beginning of matter accretion by the black hole and the late evolution of the light curve depends on the evolution of the debris fallback rate. Peak bolometric luminosities are in the range 10{sup 45}-10{sup 46} erg s{sup -1}, whereas peak luminosities in soft X-rays (0.2-2.0 keV) are typically one order of magnitude lower. The typical timescale derived from our preferred models for the flare luminosity to decay by two orders of magnitude is about 3-4 yr. Predicted soft X-ray light curves reproduce quite well data on galaxies in which a variable X-ray emission possibly related to a tidal event was detected. In the cases of NGC 3599 and IC 3599, data are reproduced well by models defined by a black hole with mass {approx}10{sup 7} M{sub sun} and a disrupted star of about 1 solar mass. The X-ray variation observed in XMMSL1 is consistent with a model defined by a black hole with mass {approx}3 x 10{sup 6} M{sub sun} and a disrupted star of 1 solar mass, while that observed in the galaxy situated in the cluster A1689 is consistent with a model including a black hole of {approx}10{sup 7} M{sub sun} and a disrupted star of {approx}0.5 M{sub sun}.

  12. EIS-0163: 1992 Columbia River Salmon Flow Measures Options Analysis/EIS

    Broader source: Energy.gov [DOE]

    The U.S. Army Corps of Engineers – Walla Walla District prepared this statement to analyze four general alternatives to modify the flow of water in the lower Columbia-Snake River in order to help anadromous fish migrate past eight multipurpose Federal dams. The U.S. Department of Energy’s Bonneville Power Administration served as a cooperating agency due to its key role in direct operation of the integrated and coordinated Columbia-Snake River System, and adopted this statement on February 10, 1992.

  13. Flow induced vibration of a cantilever column jet: a spectral analysis 

    E-Print Network [OSTI]

    Shilling, Roy Bryant

    1978-01-01

    at where y = lateral displacement of the pipe, g = acceleration due to gravity, E*= viscoelastic modulus of elasticity Figure l A Cantilever Pipe Conveying a Fluid Flow 10 M( ? +U ? ) y6x a a /? qS6x F6x (c~ +~) 6x at t qS6x F6x aI') ~ T+ ? 6... MODEL MODEL Ii'fSTRUf&ENTAT I ON . TEST PIPE DIMiEI'ISIOiVLESS CRITICAL VELOCITY AffD FREQUENCY AS A FLiNCTION OF p DRIVING MECHANIS14 . RIGIDIFIER INSTRUMEflTATION SYSTEM NATLfRAL FREQUENCIES CANTILEVER RESPONSE DYNAMICS FORCED VIBPATION...

  14. ANUDlSiTM-40 Load Flow Analysis: Base Cases, Data, Diagrams, and Results

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal GasAdministrationTechnicalTechnicalScience.govWSRC-MS-g8-00318ANUDlSiTM-40 Load Flow

  15. A spatial characterization of the Sagittarius dwarf galaxy tidal tails

    SciTech Connect (OSTI)

    Newby, Matthew; Cole, Nathan; Newberg, Heidi Jo; Willett, Benjamin [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Desell, Travis [Department of Computer Science, U. of North Dakota, Grand Forks, ND 52802 (United States); Magdon-Ismail, Malik; Szymanski, Boleslaw; Varela, Carlos [Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Yanny, Brian, E-mail: newbym2@rpi.edu, E-mail: heidi@rpi.edu [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States)

    2013-06-01

    We measure the spatial density of F turnoff stars in the Sagittarius dwarf tidal stream, from Sloan Digital Sky Survey data, using statistical photometric parallax. We find a set of continuous, consistent parameters that describe the leading Sgr stream's position, direction, and width for 15 stripes in the north Galactic cap, and three stripes in the south Galactic cap. We produce a catalog of stars that has the density characteristics of the dominant leading Sgr tidal stream that can be compared with simulations. We find that the width of the leading (north) tidal tail is consistent with recent triaxial and axisymmetric halo model simulations. The density along the stream is roughly consistent with common disruption models in the north, but possibly not in the south. We explore the possibility that one or more of the dominant Sgr streams has been misidentified, and that one or more of the ''bifurcated'' pieces is the real Sgr tidal tail, but we do not reach definite conclusions. If two dwarf progenitors are assumed, fits to the planes of the dominant and ''bifurcated'' tidal tails favor an association of the Sgr dwarf spheroidal galaxy with the dominant southern stream and the ''bifurcated'' stream in the north. In the north Galactic cap, the best fit Hernquist density profile for the smooth component of the stellar halo is oblate, with a flattening parameter q = 0.53, and a scale length of r {sub 0} = 6.73. The southern data for both the tidal debris and the smooth component of the stellar halo do not match the model fits to the north, although the stellar halo is still overwhelmingly oblate. Finally, we verify that we can reproduce the parameter fits on the asynchronous MilkyWay@home volunteer computing platform.

  16. Bifurcation analysis of surge and rotating stall in axial flow compressors

    SciTech Connect (OSTI)

    Abed, E.H. ); Houpt, P.K. . Corporate Research and Development Center); Hosny, W.M. . Engine Operability Div.)

    1993-10-01

    The surge and rotating stall post-instability behaviors of axial flow compressors are investigated from a bifurcation-theoretic perspective, using a model and system data presented by Greitzer (1976a). For this model, a sequence of local and global bifurcations of the nonlinear system dynamics is uncovered. This includes a global bifurcation of a pair of large-amplitude periodic solutions. Resulting from this bifurcation are a stable oscillation (surge) and an unstable oscillation (antisurge). The latter oscillation is found to have a deciding significance regarding the particular post-instability behavior experienced by the compressor. These results are used to reconstruct Greitzer's (1976b) findings regarding the manner in which post-instability behavior depends on system parameters. Although the model does not directly reflect non axisymmetric dynamics, use of a steady-state compressor characteristic approximating the measured characteristic of Greitzer (1976a) is found to result in conclusions that compare well with observation. Thus, the paper gives a convenient and simple explanation of the boundary between surge and rotating stall behaviors, without the use of more intricate models and analyses including non axisymmetric flow dynamics.

  17. Analysis of Flow in Pilot Operated Safety and Relief Valve of Nuclear Reactor Coolant System

    SciTech Connect (OSTI)

    Kwon, Soon-Bum; Lee, Dong-Won; Kim, In-Goo; Ahn, Hyung-Joon; Kim, Hho-Jung

    2004-07-01

    When the POSRV equipped in a nuclear power plant opens in instant by a failure in coolant system of PWR, a moving shock wave generates, and propagates downstream of the valve, inducing a complicated unsteadiness. The moving shock wave may exert severe load to the structure. In this connection, a method of gradual opening of the valve is used to reduce the load acting on the wall at the downstream of the POSRV. In the present study, experiments and calculations are performed to investigate the detail unsteady flow at the various pipe units and the effect of valve opening time on the flow downstream of the valve. In calculation by using of air as working fluid, 2-dimensional, unsteady compressible Navier-Stokes equations are solved by finite volume method. It was found that when the incident shock wave passes through the pipe unit, it may experience diffraction, reflection and interaction with a vortex. Furthermore, the geometry of the pipe unit affects the reflection type of shock wave and changes the load acting on the wall of pipe unit. It was also turned out that the maximum force acting on the wall of the pipe unit becomes in order of T-junction, 108 deg. elbow and branch in magnitude, respectively. And, the results obtained that show that the rapid pressure rise due to the moving shock wave by instant POSRV valve opening is attenuated by employing the gradual opening. (authors)

  18. Design, build and test of an axial flow hydrokinetic turbine with fatigue analysis

    E-Print Network [OSTI]

    Ketcham, Jerod W

    2010-01-01

    OpenProp is an open source propeller and turbine design and analysis code that has been in development since 2007 by MIT graduate students under the supervision of Professor Richard Kimball. In order to test the performance ...

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

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

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

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

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

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

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

    2010-01-01

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

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

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

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

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

  2. PWR FLECHT SEASET 21-rod bundle flow blockage task data and analysis report. NRC/EPRI/Westinghouse Report No. 11. Appendices K-P

    SciTech Connect (OSTI)

    Loftus, M.J.; Hochreiter, L.E.; Lee, N.; McGuire, M.F.; Wenzel, A.H.; Valkovic, M.M.

    1982-09-01

    This report presents data and limited analysis from the 21-Rod Bundle Flow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Separate Effects and Systems Effects Test Program (FLECHT SEASET). The tests consisted of forced and gravity reflooding tests utilizing electrical heater rods with a cosine axial power profile to simulate PWR nuclear core fuel rod arrays. Steam cooling and hydraulic characteristics tests were also conducted. These tests were utilized to determine effects of various flow blockage configurations (shapes and distributions) on reflooding behavior, to aid in development/assessment of computational models in predicting reflooding behavior of flow blockage configurations, and to screen flow blockage configurations for future 163-rod flow blockage bundle tests.

  3. MHK Projects/Highlands Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf Moon Cove TidalTidal Energy

  4. MHK Projects/Housatonic Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf Moon Cove TidalTidalHope

  5. High temperature flow-through device for rapid solubilization and analysis

    DOE Patents [OSTI]

    West, Jason A. A. (Castro Valley, CA); Hukari, Kyle W. (San Ramon, CA); Patel, Kamlesh D. (Dublin, CA); Peterson, Kenneth A. (Albuquerque, NM); Renzi, Ronald F. (Tracy, CA)

    2009-09-22

    Devices and methods for thermally lysing of biological material, for example vegetative bacterial cells and bacterial spores, are provided. Hot solution methods for solubilizing bacterial spores are described. Systems for direct analysis are disclosed including thermal lysers coupled to sample preparation stations. Integrated systems capable of performing sample lysis, labeling and protein fingerprint analysis of biological material, for example, vegetative bacterial cells, bacterial spores and viruses are provided.

  6. On the Natural Frequency of Tidal Current Power Systems - A Discussion...

    Office of Scientific and Technical Information (OSTI)

    On the Natural Frequency of Tidal Current Power Systems - A Discussion of Sea Testing Citation Details In-Document Search Title: On the Natural Frequency of Tidal Current Power...

  7. Snacktime for Hungry Black Holes: Theoretical Studies of the Tidal Disruption of Stars

    E-Print Network [OSTI]

    Strubbe, Linda Elisabeth

    2011-01-01

    bound gas onto the BH powers the tidal disruption flare, andof an X-ray Power-law The candidate tidal disruption eventstidal disruption spectra will contain a high-energy power-

  8. Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean...

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

    Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current, and In-Stream Hydrokinetic Power Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current,...

  9. Assessment of Energy Production Potential from Tidal Streams in the United States

    SciTech Connect (OSTI)

    Haas, Kevin A.; Fritz, Hermann M.; French, Steven P.; Smith, Brennan T.; Neary, Vincent

    2011-06-29

    The project documented in this report created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology.

  10. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    Tidal Freshwater Marsh Sustainability in the Sacramento–Sanof pulsing events to sustainability. Estuaries Coasts 18:Evaluating tidal marsh sustainability in the face of sea-

  11. On the implications of incompressibility of the quantum mechanical wavefunction in the presence of tidal gravitational fields

    E-Print Network [OSTI]

    Minter, Stephen

    2010-01-01

    of being the tidal gravitational potential energy operator,the energy shift is negative, the tidal gravitational …eldtidal gravitational …eld is treated as a perturbation to the energy

  12. Inefficient highly eccentric accretion and the low luminosity of stellar tidal disruption events

    E-Print Network [OSTI]

    Svirski, Gilad; Krolik, Julian

    2015-01-01

    Models for tidal disruption events (TDEs) in which a supermassive black hole disrupts a star commonly assume that the highly eccentric streams of bound stellar debris promptly form a circular accretion disk at the pericenter scale. However, the bolometric peak luminosity of most TDE candidates, $\\sim10^{44}\\,\\rm{erg\\,s^{-1}}$, implies that we observe only $\\sim1\\%$ of the energy expected from accretion. Moreover, recent numerical simulations (Shiokawa et al. 2015) have shown that dissipation via hydrodynamical shocks is insufficient to circularize debris orbits on the pericenter scale, and the debris flow retains its initial semi-major axis scale throughout the first $\\sim10$ orbits of the event. Motivated by these numerical results, Piran et al. (2015) suggested that the observed optical TDE emission is powered by shocks at the apocenter between freshly infalling material and earlier-arriving matter. This model explains the small radiated energy, the low temperature, and the large radius implied by the obser...

  13. Earth Tidal Analysis At Marysville Mountain Geothermal Area (1984) | Open

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, AlabamaETEC GmbH Jump to: navigation, search Name:Earlsboro,

  14. An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge JODY M. KLYMAK

    E-Print Network [OSTI]

    Balasubramanian, Ravi

    An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge JODY M. KLYMAK Scripps an estimate of 3 1.5 GW of tidal energy lost to turbulence dissipation within 60 km of the ridge and Toole 1997). Another closely related question is that of where tidal energy gets removed from the ocean

  15. The E ect of Barriers on The Tidal Range in Yong Ming Tang

    E-Print Network [OSTI]

    interest in constructing tidal barrages, either to control the tide or to extract power. CorrespondinglyThe E ect of Barriers on The Tidal Range in Estuaries Yong Ming Tang Abstract Numerical simulations of the shallow water equations are used to study the e ect of topographic barriers on the tidal range

  16. Underestimation of the UK Tidal David J.C. MacKay

    E-Print Network [OSTI]

    MacKay, David J.C.

    there and would deliver up to 40 GW (peak). In this note, I present back­of­envelope models of tidal power special cases) the power in tidal waves is not equal to the kinetic energy flux across a plane. These backUnder­estimation of the UK Tidal Resource David J.C. MacKay Cavendish Laboratory, University

  17. Under-estimation of the UK Tidal David J.C. MacKay

    E-Print Network [OSTI]

    MacKay, David J.C.

    there and would deliver up to 40 GW (peak). In this note, I present back-of-envelope models of tidal power special cases) the power in tidal waves is not equal to the kinetic energy flux across a plane. These backUnder-estimation of the UK Tidal Resource David J.C. MacKay Cavendish Laboratory, University

  18. 2306 JOURNAL OF THE ATMOSPHERIC SCIENCES Chaotic Trajectories of Tidally Perturbed Inertial Oscillations

    E-Print Network [OSTI]

    Boss, Emmanuel S.

    2306 JOURNAL OF THE ATMOSPHERIC SCIENCES Chaotic Trajectories of Tidally Perturbed Inertial ABSTRACT It is shown that tidal perturbations of a geopotential height in an inviscid, barot~opic atmos formulation of both ~he free, inertial, and the tidally forced problems permitted the application o~ the twi

  19. MARCH 2007 1 Tidal mixing hotspots governed by rapid parametric subharmonic instability

    E-Print Network [OSTI]

    MacKinnon, Jennifer

    at 21S demonstrate a rapid transfer of energy (over only a few days) to waves of half the tidal the generation site; overall 40 % of the tidal energy is dissipated locally. Further simulations indicate.9nearly 80 % of tidal energy is dissipated locally. Poleward of the critical latitude, M2/2

  20. Are mesoscale eddies in shelf seas formed by baroclinic instability of tidal fronts?

    E-Print Network [OSTI]

    Williams, Ric

    Are mesoscale eddies in shelf seas formed by baroclinic instability of tidal fronts? G. Badin,1 R; accepted 23 July 2009; published 27 October 2009. [1] The formation of eddies along tidal fronts signals are dampened by air-sea interaction and eroded by wind and tidal mixing. High-resolution CTD

  1. Dissipation at tidal and seismic frequencies in a melt-free Moon U. H. Faul,2

    E-Print Network [OSTI]

    Nimmo, Francis

    Dissipation at tidal and seismic frequencies in a melt-free Moon F. Nimmo,1 U. H. Faul,2 and E. J. Successful models can reproduce the dissipation factor (Q) measured at both tidal and seismic frequencies, and the tidal Love numbers h2 and k2, without requiring any mantle melting. However, the frequency

  2. Tidal mixing around the Maritime continent: implications for1 paleoclimate simulations2

    E-Print Network [OSTI]

    into state-of-the-art climate models. Calculation of the tidal energy flux depends on 7 1 Tidal mixing around the Maritime continent: implications for1 paleoclimate simulations2, New Haven, CT, 06511 4 Abstract 5 Tidal mixing provides an important source

  3. Critical bifurcation of shallow microtidal landforms in tidal flats and salt marshes

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    Critical bifurcation of shallow microtidal landforms in tidal flats and salt marshes Sergio by the Editorial Board April 14, 2006 (received for review September 25, 2005) Shallow tidal basins are characterized by extensive tidal flats and salt marshes that lie within specific ranges of elevation, whereas

  4. Seasonal variations of semidiurnal tidal perturbations in mesopause region temperature and zonal and meridional winds above

    E-Print Network [OSTI]

    to conserve wave energy. When propagating into the MLT region, the horizontal wind tidal amplitude can reachSeasonal variations of semidiurnal tidal perturbations in mesopause region temperature and zonal, Colorado (40.6°N, 105.1°W). The observed monthly results are in good agreement with MF radar tidal

  5. Spatial variability within a single parautochthonous Paratethyan tidal flat deposit (Karpatian, Lower Miocene Kleinebersdorf, Lower Austria)

    E-Print Network [OSTI]

    Zuschin, Martin

    Spatial variability within a single parautochthonous Paratethyan tidal flat deposit (Karpatian and Diplodonta rotundata points to a low-energy coastal setting with at least partly nutrient-rich sediment the interpretation of a parautochthonous to slightly transported tidal flat deposit. Key words: tidal flat, diversity

  6. Europa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting

    E-Print Network [OSTI]

    Head III, James William

    ; Pappalardo and Head, 2001], and 3) a seafloor plume model in which tidal energy focused in the silicate ice in the shallow crust of Europa. We show that tidal energy can be preferentially focused in risingEuropa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting

  7. Tidal and Wind Mixing versus Thermal Stratification in the South Atlantic Bight.

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    ) these fluctuations are controlled by the cycles of tidally forced mixing, heat flux, wind and river discharge. During overcome the tendency for tidal power to produce a well-mixed system". Additionally, they expressed some: heat flux, evaporation-precipitation, fresh water input, wind stress work, bottom tidal work

  8. Analysis of Aquifer Response, Groundwater Flow, and PlumeEvolution at Site OU 1, Former Fort Ord, California

    SciTech Connect (OSTI)

    Jordan, Preston D.; Oldenburg, Curtis M.; Su, Grace W.

    2005-02-24

    This report presents a continuation from Oldenburg et al. (2002) of analysis of the hydrogeology, In-Situ Permeable Flow Sensor (ISPFS) results, aquifer response, and changes in the trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County. Fuels and solvents were burned on a portion of OU 1 called the Fire Drill Area (FDA) during airport fire suppression training between 1962 and 1985. This activity resulted in soil and groundwater contamination in the unconfined A-aquifer. In the late 1980's, soil excavation and bioremediation were successful in remediating soil contamination at the site. Shortly thereafter, a groundwater pump, treat, and recharge system commenced operation. This system has been largely successful at remediating groundwater contamination at the head of the groundwater plume. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In the analyses presented here, we augment our prior work (Oldenburg et al., 2002) with new information including treatment-system totalizer data, recent water-level and chemistry data, and data collected from new wells to discern trends in contaminant migration and groundwater flow that may be useful for ongoing remediation efforts. Some conclusions from the prior study have been modified based on these new analyses, and these are pointed out clearly in this report.

  9. Disaggregating regional energy supply/demand and flow data to 173 BEAs in support of export coal analysis. Final report

    SciTech Connect (OSTI)

    Not Available

    1981-06-01

    This report documents the procedures and results of a study sponsored jointly by the US Department of Transportation and the US Department of Energy. The study was conducted to provide, Bureau of Economic Analysis (BEA)-level production/consumption data for energy materials for 1985 and 1990 in support of an analysis of transportation requirements for export coal. Base data for energy forecasts at the regional level were obtained from the Department of Energy, Energy Information Administration. The forecasts selected for this study are described in DOE/EIA's 1980 Annual Report to Congress, and are: 1985 Series, B, medium oil import price ($37.00/barrel); and 1990 Series B, medium oil import price ($41.00/barrel). Each forecast period is extensively described by approximately forty-three statistical tables prepared by EIA and made available to TERA for this study. This report provides sufficient information to enable the transportation analyst to appreciate the procedures employed by TERA to produce the BEA-level energy production/consumption data. The report presents the results of the procedures, abstracts of data tabulations, and various assumptions used for the preparation of the BEA-level data. The end-product of this effort was the BEA to BEA energy commodity flow data by more which serve as direct input to DOT's transportation network model being used for a detailed analysis of export coal transportation.

  10. High Flash-point Fluid Flow System Aerosol Flammability Study and Combustion Mechanism Analysis 

    E-Print Network [OSTI]

    Huang, Szu-Ying

    2013-12-02

    regions of three main, widely-used commercial heat transfer fluids: Paratherm NF (P-NF); Dowtherm-600 (D-600); and Plate Heat Exchange Fluid (PHE), were analyzed by electro-spray generation with laser diffraction particle analysis method. The aerosol...

  11. Pediatric Mechanical Circulatory Support Thermal Analysis of the PediaFlow Pediatric Ventricular

    E-Print Network [OSTI]

    Paden, Brad

    bearing components. Another main objective is to identify "hot spots" within the pump and ensure transfer equations with thermal finite element analysis (FEA). The models assume three main sources of waste heat gen- eration: copper motor windings, active magnetic thrust bearing windings, and eddy

  12. Seepage flow-stability analysis of the riverbank of Saigon river due to river water level fluctuation

    E-Print Network [OSTI]

    Oya, A; Hiraoka, N; Fujimoto, M; Fukagawa, R

    2015-01-01

    The Saigon River, which flows through the center of Ho Chi Minh City, is of critical importance for the development of the city as forms as the main water supply and drainage channel for the city. In recent years, riverbank erosion and failures have become more frequent along the Saigon River, causing flooding and damage to infrastructures near the river. A field investigation and numerical study has been undertaken by our research group to identify factors affecting the riverbank failure. In this paper, field investigation results obtained from multiple investigation points on the Saigon River are presented, followed by a comprehensive coupled finite element analysis of riverbank stability when subjected to river water level fluctuations. The river water level fluctuation has been identified as one of the main factors affecting the riverbank failure, i.e. removal of the balancing hydraulic forces acting on the riverbank during water drawdown.

  13. Identifying Pollutant Sources in Tidally Mixed Systems: Case Study

    E-Print Network [OSTI]

    Winant, Clinton D.

    sitessas a primary source of fecal indicator bacteria in the water column and subtidal sediments and magnitude of pollutant sources potentially responsible for the impairment. While this information mayIdentifying Pollutant Sources in Tidally Mixed Systems: Case Study of Fecal Indicator Bacteria from

  14. General relativistic tidal work for Papapetrou, Weinberg and Goldberg pseudotensors

    E-Print Network [OSTI]

    So, Lau Loi

    2015-01-01

    In 1998 Thorne claimed that all pseudotensors give the same tidal work as the Newtonian theory. In 1999, Purdue used the Landau-Lifshitz pseudotensor to calculate the tidal heating and the result matched with the Newtonian gravity. Soon after in 2001, Favata employed the same method to examine the Einstein, Bergmann-Thomson and M{\\o}ller pseudotensors, all of them give the same result as Purdue did. Inspired by the work of Purdue and Favata, for the completeness, here we manipulate the tidal work for Papapetrou, Weinberg and Goldberg pseudotensors. We obtained the same tidal work as Purdue achieved. In addition, we emphasize that a suitable gravitational energy-momentum pseudotensor requires fulfill the inside matter condition and all of the classical pseudotensors pass this test except M$\\o$ller. Moreover, we constructed a general pseudotesnor which is modified by 13 linear artificial higher order terms combination with Einstein pseudotensor. We find that the result agrees with Thorne's prediction, i.e., rel...

  15. Pasture and Soil Management Following Tidal Saltwater Intrusion 

    E-Print Network [OSTI]

    Provin, Tony; Redmon, Larry; McFarland, Mark L.; Feagley, Sam E.

    2009-05-26

    When land is flooded by saltwater, as after a hurricane tidal surge, it can long-term effects on soil productivity and fertility. This publication explains how to reclaim flooded pasture land. Having soil tested for salinity is an important step....

  16. Examining the Impacts of Tidal Energy Capture from an Ecosystem

    E-Print Network [OSTI]

    Leslie, Heather

    ; however, the contribution of alternative fuel sources to overall energy is still small. In the United are under development in the Northeast, includ- ing Roosevelt Island in New York City's East RiverP A P E R Examining the Impacts of Tidal Energy Capture from an Ecosystem Services Perspective A U

  17. Tidal Conversion by Supercritical Topography NEIL J. BALMFORTH

    E-Print Network [OSTI]

    Balmforth, Neil

    Tidal Conversion by Supercritical Topography NEIL J. BALMFORTH University of British Columbia topography on the ocean floor. The ocean is treated as infinitely deep, and the topography consists. The calculations extend the previous results of Balmforth et al. for subcritical topography (wherein waves

  18. An analytical oscillating-flow thermal analysis of the heat exchangers and regenerator in Stirling machines

    SciTech Connect (OSTI)

    Monte, F. de; Galli, G.; Marcotullio, F.

    1996-12-31

    A closed form-expression for the effectiveness of the heat exchangers and regenerator of a Stirling cycle machine is given. This result may be used in a simple way in order to evaluate their effect on the machine performance. The proposed method, indeed, allows the actual cycle gas temperatures in the heater and cooler to be obtained readily, once the geometry of the heater, cooler and regenerator is known and some quantities characterizing the engine dynamics (strokes, frequency and phase angle of the moving elements) and its heat-exchange processes (inlet temperatures of the heating and cooling fluids, and their volumetric flow rates) are measured. Thus, an immediate indication about the effectiveness of the heat exchangers and regenerator as well as about the machine thermal efficiency may be obtained. The availability of a closed-form expression for the heater, regenerator and cooler effectiveness is useful especially for those engines, like the free-piston Stirling engines, whose design requires the application of analytically based optimization criteria.

  19. Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure

    SciTech Connect (OSTI)

    Universities Space Research Association; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A.; Pluth, Janice M.

    2010-12-15

    We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 h and 24-h postirradiation, respectively. For pATF2, a saturation effect is observed with reduced expression at high doses, especially for Fe nuclei, with much slower characteristic repair times (>7 h) compared to X-rays. RBEs for pATF2 were 0.66 {+-} 0.13 and 1.66 {+-} 0.46 at 2 h and 24 h, respectively. Significant differences in {gamma}H2AX and pATF2 levels comparing irradiated samples to control were noted even at the lowest dose analyzed (0.05 Gy) using these methods of analysis. These results reveal that mathematical models can be applied to flow cytometry data to uncover important and subtle differences following exposure to various qualities of low dose radiation.

  20. Flutter analysis of a cascade of staggered blades in subsonic flow 

    E-Print Network [OSTI]

    Kronenberger, Louis

    1977-01-01

    . DEDICATION To Lynda, Michelle, and Kellie. TABLE OF CONTENTS ABSTRACT ACKNOWLEDGEMENTS DEDICATION TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES NOMENCLATURE INTRODUCTION AERODYNAMIC THEORY General Boundary Conditions Numerical Procedure... Variation on Aerodynamic Deri vati ves 26 2 Effect of Blade Segment Variation on Aerodynamic Derivatives 28 3 Summary of Two Degree of Freedom Flutter Analysis 46 LIST OF FIGURES Fi gure Cascade of Airfoi1s Blade Coordinates Two Degree of Freedom...

  1. Energy Localization Invariance of Tidal Work in General Relativity

    E-Print Network [OSTI]

    Marc Favata

    2000-08-24

    It is well known that, when an external general relativistic (electric-type) tidal field E(t) interacts with the evolving quadrupole moment I(t) of an isolated body, the tidal field does work on the body (``tidal work'') -- i.e., it transfers energy to the body -- at a rate given by the same formula as in Newtonian theory: dW/dt = -1/2 E dI/dt. Thorne has posed the following question: In view of the fact that the gravitational interaction energy between the tidal field and the body is ambiguous by an amount of order E(t)I(t), is the tidal work also ambiguous by this amount, and therefore is the formula dW/dt = -1/2 E dI/dt only valid unambiguously when integrated over timescales long compared to that for I(t) to change substantially? This paper completes a demonstration that the answer is no; dW/dt is not ambiguous in this way. More specifically, this paper shows that dW/dt is unambiguously given by -1/2 E dI/dt independently of one's choice of how to localize gravitational energy in general relativity. This is proved by explicitly computing dW/dt using various gravitational stress-energy pseudotensors (Einstein, Landau-Lifshitz, Moller) as well as Bergmann's conserved quantities which generalize many of the pseudotensors to include an arbitrary function of position. A discussion is also given of the problem of formulating conservation laws in general relativity and the role played by the various pseudotensors.

  2. The analysis of fully-developed secondary flow in a uniformly heated, horizontal annulus 

    E-Print Network [OSTI]

    Holder, Thomas Nelson

    1972-01-01

    Future D evelopment s 35 BIBLIOGRAPHY A PPENDICES VIT A Pag e 38 42 93 L IS T OF' tc I(I U Ik ES I, Di scscl. iz; tinrr Xr'crrren& lature Pag e z6 ? . Intcsiacc Analysis Pssarnete as 53 INTRO'3IIC TION Rema rha on thc Im cori ance of thc... defined, after Milne-Thompson [ 6 ] as (I7) where W is the velocity vector. Following the i'ornjulation presented above to the point of eliminating pj. . es. ure, this sjujly then introduces thc j. ransforrnation g where P is thc st roan& i...

  3. Analysis of postulated unscrammed loss of flow in SAFR using SSC

    SciTech Connect (OSTI)

    Slovik, G.C.; Van Tuyle, G.J. )

    1988-01-01

    Brookhaven National Laboratory is providing technical assistance to the US Nuclear Regulatory Commission in reviewing two advanced liquid-metal reactor (LMR) designs in order to address the licensability of these innovative concepts. The designs, PRISM and SAFR are being proposed by General Electric Company and Rockwell International (RI), respectively. Brookhaven National Laboratory has utilized the super system code (SSC) to independently evaluate the LMR reactor system response during several postulated unscrammed events. This paper describes the SAFR reactor responses to a beyond-design base event where forced cooling is lost. A similar transient analysis has already been reported for PRISM.

  4. Modeling In-stream Tidal Energy Extraction and Its Potential Environmental Impacts

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea; Geerlofs, Simon H.

    2014-09-30

    In recent years, there has been growing interest in harnessing in-stream tidal energy in response to concerns of increasing energy demand and to mitigate climate change impacts. While many studies have been conducted to assess and map tidal energy resources, efforts for quantifying the associated potential environmental impacts have been limited. This paper presents the development of a tidal turbine module within a three-dimensional unstructured-grid coastal ocean model and its application for assessing the potential environmental impacts associated with tidal energy extraction. The model is used to investigate in-stream tidal energy extraction and associated impacts on estuarine hydrodynamic and biological processes in a tidally dominant estuary. A series of numerical experiments with varying numbers and configurations of turbines installed in an idealized estuary were carried out to assess the changes in the hydrodynamics and biological processes due to tidal energy extraction. Model results indicated that a large number of turbines are required to extract the maximum tidal energy and cause significant reduction of the volume flux. Preliminary model results also indicate that extraction of tidal energy increases vertical mixing and decreases flushing rate in a stratified estuary. The tidal turbine model was applied to simulate tidal energy extraction in Puget Sound, a large fjord-like estuary in the Pacific Northwest coast.

  5. The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results and theoretical analysis of homogeneous

    E-Print Network [OSTI]

    Ford, Ian

    The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results, United Kingdom Received 24 March 2000; accepted 2 June 2000 A laminar flow tube reactor was designed

  6. Revealing the escape mechanism of three-dimensional orbits in a tidally limited star cluster

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2014-11-18

    The aim of this work is to explore the escape process of three-dimensional orbits in a star cluster rotating around its parent galaxy in a circular orbit. The gravitational field of the cluster is represented by a smooth, spherically symmetric Plummer potential, while the tidal approximation was used to model the steady tidal field of the galaxy. We conduct a thorough numerical analysis distinguishing between regular and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. It is of particular interest to locate the escape basins towards the two exit channels and relate them with the corresponding escape times of the orbits. For this purpose, we split our investigation into three cases depending on the initial value of the $z$ coordinate which was used for launching the stars. The most noticeable finding is that the majority of stars initiated very close to the primary $(x,y)$ plane move in chaotic orbits and they remain trapped for vast time intervals, while orbits with relatively high values of $z_0$ on the other hand, form well-defined basins of escape. It was also observed, that for energy levels close to the critical escape energy the escape rates of orbits are large, while for much higher values of energy most of the orbits have low escape periods or they escape immediately to infinity. We hope our outcomes to be useful for a further understanding of the dissolution process and the escape mechanism in open star clusters.

  7. To cite this version : Rigo-Mariani, Rmy and Sareni, Bruno and Roboam, Xavier Fast Power Flow Scheduling and Sensitivity Analysis for Sizing a

    E-Print Network [OSTI]

    Mailhes, Corinne

    dispatching of power flows in a microgrid with storage. The investigated approach is based on the use Scheduling and Sensitivity Analysis for Sizing a Microgrid with Storage. (2014) In: 11th International FOR SIZING A MICROGRID WITH STORAGE R. Rigo-Mariani1 , B. Sareni1 , X. Roboam1 1. Université de Toulouse

  8. ANALYSIS OF OIL TRAPPING IN POROUS MEDIA FLOW M. BERTSCH \\Lambda , R. DAL PASSO \\Lambda , AND C.J. VAN DUIJN y

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    ANALYSIS OF OIL TRAPPING IN POROUS MEDIA FLOW M. BERTSCH \\Lambda , R. DAL PASSO \\Lambda , AND C, considerably reduce the recovery factor of an oil reservoir. For instance, it is difficult to remove oil from parts of the reservoir with small scale heterogeneities. Sometimes, the oil may even remain trapped; see

  9. Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design of a fluid-flow control nano-valve

    E-Print Network [OSTI]

    Grujicic, Mica

    2005-01-01

    Materials Science and Engineering B 117 (2005) 53­61 Finite element analysis-based design A finite element method-based procedure is developed for the design of molecularly functionalized nano of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure

  10. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2012-07-01

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modelling, and the examination of more array configurations.

  11. Large-Eddy Simulation Study of Wake Propagation and Power Production in an Array of Tidal-Current Turbines: Preprint

    SciTech Connect (OSTI)

    Churchfield, M. J.; Li, Y.; Moriarty, P. J.

    2011-07-01

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally-periodic precursor simulation is performed to create turbulent flow data. Then that data is used to determine the inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modeled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. Staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement, such as the use of a larger precursor domain to better capture elongated turbulent structures, the inclusion of salinity and temperature equations to account for density stratification and its effect on turbulence, improved wall shear stress modeling, and the examination of more array configurations.

  12. Tidal dissipation in a homogeneous spherical body. I. Methods

    SciTech Connect (OSTI)

    Efroimsky, Michael; Makarov, Valeri V. E-mail: vvm@usno.navy.mil

    2014-11-01

    A formula for the tidal dissipation rate in a spherical body is derived from first principles to correct some mathematical inaccuracies found in the literature. The development is combined with the Darwin-Kaula formalism for tides. Our intermediate results are compared with those by Zschau and Platzman. When restricted to the special case of an incompressible spherical planet spinning synchronously without libration, our final formula can be compared with the commonly used expression from Peale and Cassen. However, the two turn out to differ, as in our expression the contributions from all Fourier modes are positive-definite, which is not the case with the formula from Peale and Cassen. Examples of the application of our expression for the tidal damping rate are provided in the work by Makarov and Efroimsky (Paper II) published back to back with the current paper.

  13. EA-1949: Admiralty Inlet Pilot Tidal Project, Puget Sound, WA

    Broader source: Energy.gov [DOE]

    This EA analyzes the potential environmental effects of a proposal by the Public Utility District No. 1 of Snohomish County, Washington to construct and operate the Admiralty Inlet Tidal Project. The proposed 680-kilowatt project would be located on the east side of Admiralty Inlet in Puget Sound, Washington, about 1 kilometer west of Whidbey Island, entirely within Island County, Washington. The Federal Energy Regulatory Commission (FERC) is the lead agency. The DOE NEPA process for this project has been canceled.

  14. Severn Tidal Power Group STpg | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing Capacity for Low Emission DevelopmentLakes, North Carolina:Severn Tidal

  15. Forced libration of tidally synchronized planets and moons

    E-Print Network [OSTI]

    Makarov, Valeri V; Dorland, Bryan

    2015-01-01

    Tidal dissipation of kinetic energy, when it is strong enough, tends to synchronize the rotation of planets and moons with the mean orbital motion, or drive it into long-term stable spin-orbit resonances. As the orbital motion undergoes periodic acceleration due to a finite orbital eccentricity, the spin rate oscillates around the equilibrium mean value too, giving rise to the forced, or eccentricity-driven, librations. Both the shape and amplitude of forced librations of synchronous viscoelastic planets and moons are defined by a combination of two different types of perturbative torque, the tidal torque and the triaxial torque. Consequently, forced librations can be tidally dominated (e.g., Io and possibly Titan) or deformation-dominated (e.g., the Moon) depending on a set of orbital, rheological, and other physical parameters. With small eccentricities, for the former kind, the largest term in the libration angle can be minus cosine of the mean anomaly, whereas for the latter kind, it is minus sine of the ...

  16. The Arches Cluster: Extended Structure and Tidal Radius

    E-Print Network [OSTI]

    Hosek, Matthew W; Anderson, Jay; Ghez, Andrea M; Morris, Mark R; Clarkson, William I

    2015-01-01

    At a projected distance of ~26 pc from Sgr A*, the Arches cluster provides insight to star formation in the extreme Galactic Center (GC) environment. Despite its importance, many key properties such as the cluster's internal structure and orbital history are not well known. We present an astrometric and photometric study of the outer region of the Arches cluster (R > 6.25") using HST WFC3IR. Using proper motions we calculate membership probabilities for stars down to F153M = 20 mag (~2.5 M_sun) over a 120" x 120" field of view, an area 144 times larger than previous astrometric studies of the cluster. We construct the radial profile of the Arches to a radius of 75" (~3 pc at 8 kpc), which can be well described by a single power law. From this profile we place a 3-sigma lower limit of 2.8 pc on the observed tidal radius, which is larger than the predicted tidal radius (1 - 2.5 pc). Evidence of mass segregation is observed throughout the cluster and no tidal tail structures are apparent along the orbital path. ...

  17. Hyperaccretion during tidal disruption events: Weakly bound debris envelopes and jets

    SciTech Connect (OSTI)

    Coughlin, Eric R.; Begelman, Mitchell C., E-mail: eric.coughlin@colorado.edu, E-mail: mitch@jila.colorado.edu [Also at Department of Astrophysical and Planetary Sciences, University of Colorado, UCB 391, Boulder, CO 80309, USA. (United States)

    2014-02-01

    After the destruction of the star during a tidal disruption event (TDE), the cataclysmic encounter between a star and the supermassive black hole (SMBH) of a galaxy, approximately half of the original stellar debris falls back onto the hole at a rate that can initially exceed the Eddington limit by orders of magnitude. We argue that the angular momentum of this matter is too low to allow it to attain a disk-like configuration with accretion proceeding at a mildly super-Eddington rate, the excess energy being carried away by a combination of radiative losses and radially distributed winds. Instead, we propose that the infalling gas traps accretion energy until it inflates into a weakly bound, quasi-spherical structure with gas extending nearly to the poles. We study the structure and evolution of such 'zero-Bernoulli accretion' flows as a model for the super-Eddington phase of TDEs. We argue that such flows cannot stop extremely super-Eddington accretion from occurring, and that once the envelope is maximally inflated, any excess accretion energy escapes through the poles in the form of powerful jets. We compare the predictions of our model to Swift J1644+57, the putative super-Eddington TDE, and show that it can qualitatively reproduce some of its observed features. Similar models, including self-gravity, could be applicable to gamma-ray bursts from collapsars and the growth of SMBH seeds inside quasi-stars.

  18. On the tidal radius of satellites on prograde and retrograde orbits

    E-Print Network [OSTI]

    Gajda, Grzegorz

    2015-01-01

    A tidal radius is a distance from a satellite orbiting in a host potential beyond which its material is stripped by the tidal force. We derive a revised expression for the tidal radius of a rotating satellite which properly takes into account the possibility of prograde and retrograde orbits of stars. Besides the eccentricity of the satellite orbit, the tidal radius depends also on the ratio of the satellite internal angular velocity to the orbital angular velocity. We compare our formula to the results of two $N$-body simulations of dwarf galaxies orbiting a Milky Way-like host on a prograde and retrograde orbit. The tidal radius for the retrograde case is larger than for the prograde. We introduce a kinematic radius separating stars still orbiting the dwarf galaxy from those already stripped and following the potential of the host galaxy. We find that the tidal radius matches very well the kinematic radius.

  19. Microscopic unitary description of tidal excitations in high-energy string-brane collisions

    E-Print Network [OSTI]

    Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano

    2013-11-15

    The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.

  20. Microscopic unitary description of tidal excitations in high-energy string-brane collisions

    E-Print Network [OSTI]

    D'Appollonio, Giuseppe; Vecchia, Paolo; Veneziano, Gabriele

    2013-01-01

    The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.

  1. Reachability and Timing Analysis in Data Flow Networks: A Case Study B. Antal, Gy. Csertan and I. Majzik

    E-Print Network [OSTI]

    Firenze, Università degli Studi di

    modeled by data flow networks. The model is validated indirectly as it is transformed to Petri nets is done automatically. The correspondence between data flow networks and Petri nets is a natural idea [6 networks and then the class of the corre- sponding Petri nets. [5] introduces a transformation from DFN

  2. CFD Analysis of Core Bypass Flow and Crossflow in the Prismatic Very High Temperature Gas-cooled Nuclear Reactor 

    E-Print Network [OSTI]

    Wang, Huhu 1985-

    2012-12-13

    effect. The bypass flow occurs when the coolant flow into gaps between fuel blocks. These gaps are formed as a result of carbon expansion and shrinkage induced by radiations and manufacturing and installation errors. Hot spots may appear in the core...

  3. Mechanisms generating modification of benthos following tidal flat invasion by a Spartina hybrid

    E-Print Network [OSTI]

    Neira, C; Grosholz, E D; Levin, L A; Blake, R

    2006-01-01

    1997. Kinetics of tidal resuspension of microbiota: testingare susceptible to resuspension following bio- turbation (in barnacle recruitment and resuspension of adult benthic

  4. MECHANISMS GENERATING MODIFICATION OF BENTHOS FOLLOWING TIDAL FLAT INVASION BY A SPARTINA HYBRID

    E-Print Network [OSTI]

    Neira, Carlos; Grosholz, Edwin D; Levin, Lisa A; Blake, Rachael

    2006-01-01

    1997. Kinetics of tidal resuspension of microbiota: testingare susceptible to resuspension following bio- turbation (in barnacle recruitment and resuspension of adult benthic

  5. Modeling the Effects of Tidal Energy Extraction on Estuarine Hydrodynamics in a Stratified Estuary

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-15

    A three-dimensional coastal ocean model with a tidal turbine module was used in this paper to study the effects of tidal energy extraction on temperature and salinity stratification and density driven two-layer estuarine circulation. Numerical experiments with various turbine array configurations were carried out to investigate the changes in tidally mean temperature, salinity and velocity profiles in an idealized stratified estuary that connects to coastal water through a narrow tidal channel. The model was driven by tides, river inflow and sea surface heat flux. To represent the realistic size of commercial tidal farms, model simulations were conducted based on a small percentage of the total number of turbines that would generate the maximum extractable energy in the system. Model results indicated that extraction of tidal energy will increase the vertical mixing and decrease the stratification in the estuary. Extraction of tidal energy has stronger impact on the tidally-averaged salinity, temperature and velocity in the surface layer than the bottom. Energy extraction also weakens the two-layer estuarine circulation, especially during neap tides when tidal mixing the weakest and energy extraction is the smallest. Model results also show that energy generation can be much more efficient with higher hub height with relatively small changes in stratification and two-layer estuarine circulation.

  6. Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030...

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

    Office What are the key documents? Mapping and Assessment of the United States Ocean Wave Energy Resource pdf here Assessment of Energy Production Potential from Tidal Streams...

  7. Computational analysis of fluid flow and zonal deposition in ferrocyanide single-shell tanks. Ferrocyanide Safety Program

    SciTech Connect (OSTI)

    McGrail, B.P.; Trent, D.S.; Terrones, G.; Hudson, J.D.; Michener, T.E.

    1993-10-01

    Safety of single-shell tanks containing ferrocyanide wastes is of concern. Ferrocyanide in the presence of an oxidizer such as NaNO{sub 3} or NaNO{sub 2} is explosively combustible when concentrated and heated. Evaluating the processes that could affect the fuel content of waste and distribution of the tank heat load is important. Highly alkaline liquid wastes were transferred in and out of the tanks over several years. Since Na{sub 2}NiFe(CN){sub 6} is much more soluble in alkaline media, the ferrocyanide could be dispersed from the tank more easily. If Cs{sub 2}NiFe(CN){sub 6} or CsNaNiFe(CN){sub 6} are also soluble in alkaline media, solubilization and transport of {sup 137}Cs could also occur. Transporting this heat generating radionuclide to a localized area in the tanks is a potential mechanism for generating a ``hot spot.`` Fluid convection could potentially speed the transport process considerably over aqueous diffusion alone. A stability analysis was performed for a dense fluid layer overlying a porous medium saturated by a less dense fluid with the finding that the configuration is unconditionally unstable and independent of the properties of the porous medium or the magnitude of the fluid density difference. A parametric modeling study of the buoyancy-driven flow due to a thermal gradient was combusted to establish the relationship between the waste physical and thermal properties and natural convection heat transfer. The effects of diffusion and fluid convection on the redistribution of the {sup 137}Cs were evaluated with a 2-D coupled heat and mass transport model. The maximum predicted temperature rise associated with the formation of zones was only 5{degrees}C and thus is of no concern in terms of generating a localized ``hot spot.``

  8. Jets from Tidal Disruptions of Stars by Black Holes

    E-Print Network [OSTI]

    Julian H. Krolik; Tsvi Piran

    2012-02-07

    Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is comparable to the inner accretion disk pressure, a powerful jet may form whose luminosity can easily exceed the thermal UV luminosity. When the jet beam points at Earth, its non-thermal luminosity can dominate the emitted spectrum. The thermal and non-thermal components decay differently with time. In particular, the thermal emission should remain roughly constant for a significant time after the period of maximum accretion, beginning to diminish only after a delay, whereas after the peak accretion rate, the non-thermal jet emission decays, but then reaches a plateau. Both transitions are tied to a characteristic timescale $t_{\\rm Edd}$ at which the accretion rate falls below Eddington. Making use of this timescale in a new parameter-inference formalism for tidal disruption events with significant emission from a jet, we analyze the recent flare source Swift J2058. It is consistent with an event in which a main sequence solar-type staris disrupted by a black hole of mass $\\sim 4 \\times 10^7 M_{\\odot}$. The beginning of the flat phase in the non-thermal emission from this source can possibly be seen in the late-time lightcurve. Optical photometry over the first $\\simeq 40$ d of this flare is also consistent with this picture, but is only weakly constraining because the bolometric correction is very uncertain. We suggest that future searches for main sequence tidal disruptions use methods sensitive to jet radiation as well as to thermal UV radiation.

  9. MHK Projects/Rockaway Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas:Montezuma,Information MHKMHK5 < MHKKembla < MHK Projects JumpRockaway Tidal

  10. The Wash Tidal Barrier Corporation | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc JumpHeterInformation Policy andInstitute JumpWash Tidal Barrier

  11. List of Tidal Energy Incentives | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History ViewInformationWindsCompressedList of RefuelingRoomList ofSolarTidal

  12. MHK Projects/Avalon Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31 <Avalon Tidal < MHK

  13. MHK Projects/BW2 Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31 <Avalon Tidal <BW2

  14. MHK Projects/Cape May Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 Jump to:Projects/Alaska 31BondurantCETO3May Tidal

  15. MHK Projects/Killisnoo Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf MoonKillisnoo Tidal Energy <

  16. MHK Projects/Kingsbridge Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf MoonKillisnoo Tidal Energy

  17. MHK Projects/Margate Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf| Open EnergyMaineMargate Tidal

  18. MHK Projects/Maurice River Tidal | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf| OpenMaurice River Tidal <

  19. MHK Projects/Salem Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos BayOysterReliance LightSalem Tidal Energy

  20. MHK Technologies/Sabella subsea tidal turbine | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050Enermar <OMIS D E < MHKSPERBOY <subsea tidal

  1. Hydropower, Wave and Tidal Technologies - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower, Wave and Tidal » Technology

  2. Sandia Energy - Tidal & Current Modeling Development and Validation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochasticunique wind(CREW)Tidal &

  3. Discussion by Ian Reid Seydell et al. provide an interesting analysis of inferred flow within the hyporheus of

    E-Print Network [OSTI]

    the river bed are isotropic. The stratigraphy of both ancient (e.g., Nemec and Steel, 1984) and modern (e-flow deposits. In: Koster, E.H. and Steel, R.J. (Eds), Sedimentology of gravels and conglomerates. Memoir

  4. A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation 

    E-Print Network [OSTI]

    Haghshenas, Arash

    2013-04-24

    The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster...

  5. Experimental analysis of the vorticity and turbulent flow dynamics of a pitching airfoil at realistic flight (helicopter) conditions 

    E-Print Network [OSTI]

    Sahoo, Dipankar

    2008-10-10

    Improved basic understanding, predictability, and controllability of vortex-dominated and unsteady aerodynamic flows are important in enhancement of the performance of next generation helicopters. The primary objective of this research project...

  6. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01

    better reflects flow maldistribution phenomena that wouldnumber. Therefore, flow maldistribution will create areasthat is where flow maldistribution is most likely to occur

  7. EOF analysis of a time series with application to tsunami detection

    E-Print Network [OSTI]

    Tolkova, Elena

    -space basis can be derived via Empirical Orthogonal Function (EOF) analysis of a tidal record of a single buoy. Decomposition of a tsunami buoy record in a functional space of tidal EOFs presents an efficient tool and quantification (Tolkova, E. 2009. Principal Component Analysis of Tsunami Buoy Record: Tide Prediction

  8. RED CLUMP STARS IN THE SAGITTARIUS TIDAL STREAMS

    SciTech Connect (OSTI)

    Carrell, Kenneth; Chen Yuqin; Wilhelm, Ronald

    2012-07-15

    We have probed a section (l {approx} 150, b {approx} -60) of the trailing tidal arm of the Sagittarius dwarf spheroidal galaxy by identifying a sample of Red Clump (RC) stream stars. RC stars are not generally found in the halo field, but are found in significant numbers in both the Sagittarius galaxy and its tidal streams, making them excellent probes of stream characteristics. Our target sample was selected using photometric data from the Sloan Digital Sky Survey, Data Release 6, which was constrained in color to match the Sagittarius RC stars. Spectroscopic observations of the target stars were conducted at Kitt Peak National Observatory using the WIYN telescope. The resulting spectroscopic sample is magnitude limited and contains both main-sequence disk stars and evolved RC stars. We have developed a method to systematically separate these two stellar classes using kinematic information and a Bayesian approach for surface gravity determination. The resulting RC sample allows us to determine an absolute stellar density of {rho} = 2.7 {+-} 0.5 RC stars kpc{sup -3} at this location in the stream. Future measurements of stellar densities for a variety of populations and at various locations along the streams will lead to a much improved understanding of the original nature of the Sagittarius galaxy and the physical processes controlling its disruption and subsequent stream generation.

  9. Relativistic effects on tidal disruption kicks of solitary stars

    E-Print Network [OSTI]

    Gafton, Emanuel; Guillochon, James; Korobkin, Oleg; Rosswog, Stephan

    2015-01-01

    Solitary stars that wander too close to their galactic centres can become tidally disrupted, if the tidal forces due to the supermassive black hole (SMBH) residing there overcome the self-gravity of the star. If the star is only partially disrupted, so that a fraction survives as a self-bound object, this remaining core will experience a net gain in specific orbital energy, which translates into a velocity "kick" of up to $\\sim 10^3$ km/s. In this paper, we present the result of smoothed particle hydrodynamics (SPH) simulations of such partial disruptions, and analyse the velocity kick imparted on the surviving core. We compare $\\gamma$ = 5/3 and $\\gamma$ = 4/3 polytropes disrupted in both a Newtonian potential, and a generalized potential that reproduces most relativistic effects around a Schwarzschild black hole either exactly or to excellent precision. For the Newtonian case, we confirm the results of previous studies that the kick velocity of the surviving core is virtually independent of the ratio of the...

  10. The Magellanic Bridge: The Nearest Purely Tidal Stellar Population

    E-Print Network [OSTI]

    Jason Harris

    2006-12-04

    We report on observations of the stellar populations in twelve fields spanning the region between the Magellanic Clouds, made with the Mosaic-II camera on the 4-meter telescope at the Cerro-Tololo Inter-American Observatory. The two main goals of the observations are to characterize the young stellar population (which presumably formed in situ in the Bridge and therefore represents the nearest stellar population formed from tidal debris), and to search for an older stellar component (which would have been stripped from either Cloud as stars, by the same tidal forces which formed the gaseous Bridge). We determine the star-formation history of the young inter-Cloud population, which provides a constraint on the timing of the gravitational interaction which formed the Bridge. We do not detect an older stellar population belonging to the Bridge in any of our fields, implying that the material that was stripped from the Clouds to form the Magellanic Bridge was very nearly a pure gas.

  11. Tidal Dwarf Galaxies: Disc Formation at z=0

    E-Print Network [OSTI]

    Lelli, Federico; Brinks, Elias; McGaugh, Stacy S

    2015-01-01

    Collisional debris around interacting and post-interacting galaxies often display condensations of gas and young stars that can potentially form gravitationally bound objects: Tidal Dwarf Galaxies (TDGs). We summarise recent results on TDGs, which are originally published in Lelli et al. (2015, A&A). We study a sample of six TDGs around three different interacting systems, using high-resolution HI observations from the Very Large Array. We find that the HI emission associated to TDGs can be described by rotating disc models. These discs, however, would have undergone less than one orbit since the time of the TDG formation, raising the question of whether they are in dynamical equilibrium. Assuming that TDGs are in dynamical equilibrium, we find that the ratio of dynamical mass to baryonic mass is consistent with one, implying that TDGs are devoid of dark matter. This is in line with the results of numerical simulations where tidal forces effectively segregate dark matter in the halo from baryonic matter i...

  12. HAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET

    E-Print Network [OSTI]

    Dushaw, Brian

    HAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET Principal). This tidal energy budget will determine limits on the energy dissipated in the nearfield of the Hawaiian and ocean acoustic tomography have brought a new dimension to the subject. We propose to measure the energy

  13. JULY 2005 1 An estimate of tidal energy lost to turbulence at the Hawaiian Ridge

    E-Print Network [OSTI]

    Klymak, Jody M.

    JULY 2005 1 An estimate of tidal energy lost to turbulence at the Hawaiian Ridge JODY M. KLYMAK1 of the ridge, giving an estimate of 3±1.5 GW of tidal energy lost to turbulence dissipation within 60 km relation- ship between the energy in the semi-diurnal internal tide (E) and the depth

  14. ORNL/TM-2012/301 Experimental Test Plan DOE Tidal

    E-Print Network [OSTI]

    Siefert, Chris

    ORNL/TM-2012/301 Experimental Test Plan ­ DOE Tidal And River Reference Turbines August 2012 Test Plan ­ DOE Tidal and River Reference Turbines Vincent S. Neary1 Craig Hill2 Leonardo P. Chamorro 2 16, 2012 Prepared for: Wind and Water Power Technologies Program Office of Energy Efficiency

  15. time scale observed in some close binary systems (19), and tidal dissipation (20)

    E-Print Network [OSTI]

    Stanley, H. Eugene

    time scale observed in some close binary systems (19), and tidal dissipation (20) may also cause). At this stage, the core of star A undergoes collapse, and the residual nuclear fuel is ignited to power aware that both tidal and general relativistic ef- fects will be important in this system

  16. Post Doctoral (OR Research Engineer) fellowship Distributed Control of a Tidal Farm

    E-Print Network [OSTI]

    Condat, Laurent

    Post Doctoral (OR Research Engineer) fellowship Distributed Control of a Tidal Farm Context on con- trol systems and power systems) and ALSTOM-ocean (world- wide leader in turbines construction and operating a tidal farm of 30-200 MW. Successful applicants will work at GIPSA-lab (Grenoble) (http

  17. Numerical and Analytical Estimates of M2 Tidal Conversion at Steep Oceanic Ridges EMANUELE DI LORENZO

    E-Print Network [OSTI]

    Young, William R.

    of mechanical energy required to mix the global ocean (Garrett and St. Laurent 2002). Tidal forces perform aboutNumerical and Analytical Estimates of M2 Tidal Conversion at Steep Oceanic Ridges EMANUELE DI) ABSTRACT Numerical calculations of the rate at which energy is converted from the external to internal

  18. Can Earth's rotation and tidal despinning drive plate tectonics? Federica Riguzzi a,c,

    E-Print Network [OSTI]

    Can Earth's rotation and tidal despinning drive plate tectonics? Federica Riguzzi a,c, , Giuliano January 2009 Accepted 10 June 2009 Available online xxxx Keywords: Plate tectonics Earth's rotation Tidal despinning Earth's energy budget We re-evaluate the possibility that Earth's rotation contributes to plate

  19. Expressions for Tidal Conversion at Seafloor Topography using Physical-Space Integrals

    E-Print Network [OSTI]

    Schörghofer, Norbert

    Expressions for Tidal Conversion at Seafloor Topography using Physical-Space Integrals Norbert and a potential source of the required mechanical energy is the generation and breaking of internal gravity waves (Egbert and Ray, 2000; Ledwell et al., 2000). Tidal dissipation has long been recognized as important

  20. Cross-shore sediment transport and the equilibrium morphology of mudflats under tidal currents

    E-Print Network [OSTI]

    Hogg, Andrew

    Cross-shore sediment transport and the equilibrium morphology of mudflats under tidal currents D of suspended sediment transport under cross-shore tidal currents on an intertidal mudflat. We employ a Lagrangian formulation to obtain periodic solutions for the sediment transport over idealized bathymetries

  1. Chapter 5 -Sediment, Nutrient, and Vegetation Trends Along the Tidal, Forested Pocomoke

    E-Print Network [OSTI]

    Chapter 5 - Sediment, Nutrient, and Vegetation Trends Along the Tidal, Forested Pocomoke River-tidal upstream sites. Floodplain sediments in the past W.H. Conner, T.W. Doyle, and K.W. Krauss (eds.), Ecology]). These sediments overlie hundreds of meters of Tertiary (2-65 mybp) greensands and clay- silt. The Tertiary

  2. Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid

    E-Print Network [OSTI]

    Victoria, University of

    Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid by Susan Margot Boronowski Committee Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid by Susan Margot only be practical at power penetration levels less than 20%. #12;iv Table of Contents Supervisory

  3. Scaling laws to quantify tidal dissipation in star-planet systems

    E-Print Network [OSTI]

    Auclair-Desrotour, Pierre; Poncin-Lafitte, Christophe Le

    2015-01-01

    Planetary systems evolve over secular time scales. One of the key mechanisms that drive this evolution is tidal dissipation. Submitted to tides, stellar and planetary fluid layers do not behave like rocky ones. Indeed, they are the place of resonant gravito-inertial waves. Therefore, tidal dissipation in fluid bodies strongly depends on the excitation frequency while this dependence is smooth in solid ones. Thus, the impact of the internal structure of celestial bodies must be taken into account when studying tidal dynamics. The purpose of this work is to present a local model of tidal gravito-inertial waves allowing us to quantify analytically the internal dissipation due to viscous friction and thermal diffusion, and to study the properties of the resonant frequency spectrum of the dissipated energy. We derive from this model scaling laws characterizing tidal dissipation as a function of fluid parameters (rotation, stratification, diffusivities) and discuss them in the context of star-planet systems.

  4. Modeling Tidal Stream Energy Extraction and its Effects on Transport Processes in a Tidal Channel and Bay System Using a Three-dimensional Coastal Ocean Model

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.

    2013-02-28

    This paper presents a numerical modeling study for simulating in-stream tidal energy extraction and assessing its effects on the hydrodynamics and transport processes in a tidal channel and bay system connecting to coastal ocean. A marine and hydrokinetic (MHK) module was implemented in a three-dimensional (3-D) coastal ocean model using the momentum sink approach. The MHK model was validated with the analytical solutions for tidal channels under one-dimensional (1-D) conditions. Model simulations were further carried out to compare the momentum sink approach with the quadratic bottom friction approach. The effects of 3-D simulations on the vertical velocity profile, maximum extractable energy, and volume flux reduction across the channel were investigated through a series of numerical experiments. 3-D model results indicate that the volume flux reduction at the maximum extractable power predicted by the 1-D analytical model or two-dimensional (2-D) depth-averaged numerical model may be overestimated. Maximum extractable energy strongly depends on the turbine hub height in the water column, and which reaches a maximum when turbine hub height is located at mid-water depth. Far-field effects of tidal turbines on the flushing time of the tidal bay were also investigated. Model results demonstrate that tidal energy extraction has a greater effect on the flushing time than volume flux reduction, which could negatively affect the biogeochemical processes in estuarine and coastal waters that support primary productivity and higher forms of marine life.

  5. Three-dimensional structures of equatorial waves and the resulting super-rotation in the atmosphere of a tidally locked hot Jupiter

    SciTech Connect (OSTI)

    Tsai, Shang-Min; Gu, Pin-Gao; Dobbs-Dixon, Ian

    2014-10-01

    Three-dimensional (3D) equatorial trapped waves excited by stellar isolation and the resulting equatorial super-rotating jet in a vertical stratified atmosphere of a tidally locked hot Jupiter are investigated. Taking the hot Jupiter HD 189733b as a fiducial example, we analytically solve linear equations subject to stationary stellar heating with a uniform zonal-mean flow included. We also extract wave information in the final equilibrium state of the atmosphere from our radiative hydrodynamical simulation for HD 189733b. Our analytic wave solutions are able to qualitatively explain the 3D simulation results. Apart from previous wave studies, investigating the vertical structure of waves allows us to explore new wave features such as the wavefronts tilts related to the Rossby-wave resonance as well as dispersive equatorial waves. We also attempt to apply our linear wave analysis to explain some numerical features associated with the equatorial jet development seen in the general circulation model by Showman and Polvani. During the spin-up phase of the equatorial jet, the acceleration of the jet can be in principle boosted by the Rossby-wave resonance. However, we also find that as the jet speed increases, the Rossby-wave structure shifts eastward, while the Kelvin-wave structure remains approximately stationary, leading to the decline of the acceleration rate. Our analytic model of jet evolution implies that there exists only one stable equilibrium state of the atmosphere, possibly implying that the final state of the atmosphere is independent of initial conditions in the linear regime. Limitations of our linear model and future improvements are also discussed.

  6. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    tidal freshwater marsh sites in the Delta Site name Coordinates Area (ha) Elevation above MSL (cm) Salinity regime Energy

  7. Modeling Tidal Freshwater Marsh Sustainability in the Sacramento–San Joaquin Delta Under a Broad Suite of Potential Future Scenarios

    E-Print Network [OSTI]

    Swanson, Kathleen M.; Drexler, Judith Z.; Fuller, Christopher C.; Schoellhamer, David H.

    2015-01-01

    Table 1 Location and basic characteristics of tidal freshwater marsh sites in the Delta Site name Coordinates

  8. Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.

    SciTech Connect (OSTI)

    Baptista, António M. [Oregon Health & Science University, Science and Technology Center for Coastal Margin Observation and Prediction

    2009-08-02

    This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary/plume variability, the role of the estuary and plume on salmon survival, and functional changes in the estuary-plume system in response to climate and human activities.

  9. Field Measurements at River and Tidal Current Sites for Hydrokinetic Energy Development: Best Practices Manual

    SciTech Connect (OSTI)

    Neary, Vincent S; Gunawan, Budi

    2011-09-01

    In this report, existing data collection techniques and protocols for characterizing open channel flows are reviewed and refined to further address the needs of the MHK industry. The report provides an overview of the hydrodynamics of river and tidal channels, and the working principles of modern acoustic instrumentation, including best practices in remote sensing methods that can be applied to hydrokinetic energy site characterization. Emphasis is placed upon acoustic Doppler velocimeter (ADV) and acoustic-Doppler current profiler (ADCP) instruments, as these represent the most practical and economical tools for use in the MHK industry. Incorporating the best practices as found in the literature, including the parameters to be measured, the instruments to be deployed, the instrument deployment strategy, and data post-processing techniques. The data collected from this procedure aims to inform the hydro-mechanical design of MHK systems with respect to energy generation and structural loading, as well as provide reference hydrodynamics for environmental impact studies. The standard metrics and protocols defined herein can be utilized to guide field experiments with MHK systems.

  10. Tidal Residual Eddies and their Effect on Water Exchange in Puget Sound

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-30

    Tidal residual eddies are one of the important hydrodynamic features in tidally dominant estuaries and coastal bays, and they could have significant effects on water exchange in a tidal system. This paper presents a modeling study of tides and tidal residual eddies in Puget Sound, a tidally dominant fjord-like estuary in the Pacific Northwest coast, using a three-dimensional finite-volume coastal ocean model. Mechanisms of vorticity generation and asymmetric distribution patterns around an island/headland were analyzed using the dynamic vorticity transfer approach and numerical experiments. Model results of Puget Sound show that a number of large twin tidal residual eddies exist in the Admiralty Inlet because of the presence of major headlands in the inlet. Simulated residual vorticities near the major headlands indicate that the clockwise tidal residual eddy (negative vorticity) is generally stronger than the anticlockwise eddy (positive vorticity) because of the effect of Coriolis force. The effect of tidal residual eddies on water exchange in Puget Sound and its sub-basins were evaluated by simulations of dye transport. It was found that the strong transverse variability of residual currents in the Admiralty Inlet results in a dominant seaward transport along the eastern shore and a dominant landward transport along the western shore of the Inlet. A similar transport pattern in Hood Canal is caused by the presence of tidal residual eddies near the entrance of the canal. Model results show that tidal residual currents in Whidbey Basin are small in comparison to other sub-basins. A large clockwise residual circulation is formed around Vashon Island near entrance of South Sound, which can potentially constrain the water exchange between the Central Basin and South Sound.

  11. Voltage Collapse and ODE Approach to Power Flows: Analysis of a Feeder Line with Static Disorder in Consumption/Production

    E-Print Network [OSTI]

    Chertkov, M; Turtisyn, K; Chernyak, V; Lebedev, V

    2011-01-01

    We consider a model of a distribution feeder connecting multiple loads to the sub-station. Voltage is controlled directly at the head of the line (sub-station), however, voltage anywhere further down the line is subject to fluctuations, caused by irregularities of real and reactive distributed power consumption/generation. The lack of a direct control of voltage along the line may result in the voltage instability, also called voltage collapse - phenomenon well known and documented in the power engineering literature. Motivated by emerging photo-voltaic technology, which brings a new source of renewable generation but also contributes significant increase in power flow fluctuations, we reexamine the phenomenon of voltage stability and collapse. In the limit where the number of consumers is large and spatial variations in power flows are smooth functions of position along the feeder, we derive a set of the power flow Ordinary Differential Equations (ODE), verify phenomenon of voltage collapse, and study the ef...

  12. Development of one-dimensional computational fluid dynamics code 'GFLOW' for groundwater flow and contaminant transport analysis

    SciTech Connect (OSTI)

    Rahatgaonkar, P. S.; Datta, D.; Malhotra, P. K.; Ghadge, S. G. [Nuclear Power Corporation of India Ltd., R-2, Ent. Block, Nabhikiya Urja Bhavan, Anushakti Nagar, Mumbai - 400 094 (India)

    2012-07-01

    Prediction of groundwater movement and contaminant transport in soil is an important problem in many branches of science and engineering. This includes groundwater hydrology, environmental engineering, soil science, agricultural engineering and also nuclear engineering. Specifically, in nuclear engineering it is applicable in the design of spent fuel storage pools and waste management sites in the nuclear power plants. Ground water modeling involves the simulation of flow and contaminant transport by groundwater flow. In the context of contaminated soil and groundwater system, numerical simulations are typically used to demonstrate compliance with regulatory standard. A one-dimensional Computational Fluid Dynamics code GFLOW had been developed based on the Finite Difference Method for simulating groundwater flow and contaminant transport through saturated and unsaturated soil. The code is validated with the analytical model and the benchmarking cases available in the literature. (authors)

  13. Estimation vido haute frquence de la topographie inter-tidale d'une plage sableuse : application la

    E-Print Network [OSTI]

    Estimation vidéo haute fréquence de la topographie inter- tidale d'une plage sableuse : application outil vidéo d'estimation haute fréquence de la topographie inter-tidale. Cet outil est basé sur le suivi : We present a tool to estimate inter-tidal topography using video images. This tool is based

  14. Tidal front affects the size of prey used by a top marine predator, the short-tailed shearwater (Puffinus tenuirostris)

    E-Print Network [OSTI]

    Tidal front affects the size of prey used by a top marine predator, the short-tailed shearwater densities of small euphausiids were associated with a tidal front on the north side of Akutan Pass. At most sites elsewhere in the Bering Sea, away from tidal fronts, shearwaters selected larger (14.2­20.1 mm

  15. Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model 

    E-Print Network [OSTI]

    O'Neal, D.L.; Bassiouny, R.

    2004-01-01

    to an increase in the ambien perature above the system design point, a rigi rt-tube can sometimes provide a high enough flow e to flood the compressor with saturated refrigerant the other hand, when the condenser pressur . 1. Schematic of the flexible short...Pa were studied. Four upstream and downstream pressures were applied and the upstream subcooling was held at a constant value of 16.7 ?C. Mass flow rates from the numerical model were compared to available published experimental results. The study showed...

  16. OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES

    SciTech Connect (OSTI)

    Van Velzen, Sjoert; Farrar, Glennys R. [Center for Cosmology and Particle Physics, New York University, NY 10003 (United States); Gezari, Suvi [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Morrell, Nidia [Carnegie Observatories, Las Campanas Observatory, Casillas 601, La Serena (Chile); Zaritsky, Dennis [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Oestman, Linda [Institut de Fisica d'Altes Energies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Barcelona) (Spain); Smith, Mathew [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch, 7701 (South Africa); Gelfand, Joseph [New York University-Abu Dhabi, Abu Dhabi (United Arab Emirates); Drake, Andrew J., E-mail: s.vanvelzen@astro.ru.nl [Center for Advance Computing Research, California Institute of Technology, Pasadena, CA 91225 (United States)

    2011-11-10

    Using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by supermassive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. The TDE flares have optical blackbody temperatures of 2 Multiplication-Sign 10{sup 4} K and observed peak luminosities of M{sub g} = -18.3 and -20.4 ({nu}L{sub {nu}} = 5 Multiplication-Sign 10{sup 42}, 4 Multiplication-Sign 10{sup 43} erg s{sup -1}, in the rest frame); their cooling rates are very low, qualitatively consistent with expectations for tidal disruption flares. The properties of the TDE candidates are examined using (1) SDSS imaging to compare them to other flares observed in the search, (2) UV emission measured by GALEX, and (3) spectra of the hosts and of one of the flares. Our pipeline excludes optically identifiable AGN hosts, and our variability monitoring over nine years provides strong evidence that these are not flares in hidden AGNs. The spectra and color evolution of the flares are unlike any SN observed to date, their strong late-time UV emission is particularly distinctive, and they are nuclear at high resolution arguing against these being first cases of a previously unobserved class of SNe or more extreme examples of known SN types. Taken together, the observed properties are difficult to reconcile with an SN or an AGN-flare explanation, although an entirely new process specific to the inner few hundred parsecs of non-active galaxies cannot be excluded. Based on our observed rate, we infer that hundreds or thousands of TDEs will be present in current and next-generation optical synoptic surveys. Using the approach outlined here, a TDE candidate sample with O(1) purity can be selected using geometric resolution and host and flare color alone, demonstrating that a campaign to create a large sample of TDEs, with immediate and detailed multi-wavelength follow-up, is feasible. A by-product of this work is quantification of the power spectrum of extreme flares in AGNs.

  17. Mathematical analysis and numerical simulation of multi-phase multi-component flow in heterogeneous porous media

    E-Print Network [OSTI]

    Cirpka, Olaf Arie

    methods Mathematical modelling CO2 storage Enhanced oil recovery Groundwater contamination Multi-phase multi-component flow processes are fundamental to engineering applications in hydrocarbon and geothermal The transport of dissolved chemical components (e.g., CO2, NaCl, CH4) in different fluid phases (e.g., water

  18. Recoding of the stop codon UGA to glycine by a BD1-5/SN-2 bacterium and niche partitioning between Alpha- and Gammaproteobacteria in a tidal sediment microbial community naturally selected in a laboratory chemostat

    SciTech Connect (OSTI)

    Hanke, Anna; Hamann, Emmo; Sharma, Ritin; Geelhoed, Jeanine; Hargesheimer, Theresa; Kraft, Beate; Meyer, Volker; Lenk, Sabine; Osmers, Harald; Wu, Rong; Makinwa, Kofi; Hettich, Robert {Bob} L; Banfield, Jillian F.; Tegetmeyer, Halina; Strouss, Marc

    2014-01-01

    Sandy coastal sediments are global hot spots for microbial mineralization of organic matter and denitrification. These sediments are characterized by advective pore water flow, tidal cycling and an active and complex microbial community. Metagenomic sequencing of microbial communities sampled from such sediments showed that potential sulfuroxidizing Gammaproteobacteria and members of the enigmaticBD1-5/ SN-2 candidatephylumwereabundantinsitu (>10% and 2% respectively). By mimicking the dynamic oxic/anoxic environmental conditions of the sedimentin a laboratory chemostat, a simplified microbial community was selected from the more complex inoculum. Metagenomics, proteomics and fluorescenceinsituhybridization showed that this simplified community contained both a potential sulfuroxidizing Gamma proteobacteria (at 24 2% abundance) and a member of the BD1-5 / SN-2candidatephylum (at 7 6%abundance). Despite the abundant supply of organic substrates to the chemostat, proteomic analysis suggested that the selected gamma proteobacterium grew partially auto trophically and performed hydrogen/formate oxidation. The enrichment of a member of the BD1-5/SN-2candidatephylum enabled, for the first time, direct microscopic observation by fluorescent insitu hybridization and the experimental validation of the previously predicted translation of the stop codon UGA into glycine.

  19. Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes

    E-Print Network [OSTI]

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01

    We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

  20. A 22 Degree Tidal Tail for Palomar 5

    E-Print Network [OSTI]

    C. J. Grillmair; O. Dionatos

    2006-03-02

    Using Data Release 4 of the Sloan Digital Sky Survey, we have applied an optimal contrast, matched filter technique to trace the trailing tidal tail of the globular cluster Palomar 5 to a distance of 18.5 degrees from the center of the cluster. This more than doubles the total known length of the tail to some 22 degrees on the sky. Based on a simple model of the Galaxy, we find that the stream's orientation on the sky is consistent at the 1.7 sigma level with existing proper motion measurements. We find that a spherical Galactic halo is adequate to model the stream over its currently known length, and we are able to place new constraints on the current space motion of the cluster.

  1. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2014-01-01

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{c...

  2. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2014-12-28

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{cm}\\mid_{r_{+} = \\frac{M}{M_{p}^2}}: E_{cm}\\mid_{r_{mb} = \\left(\\frac{3+\\sqrt{5}}{2}\\right)\\frac{M}{M_{p}^2}}:E_{cm}\\mid_{r_{ISCO} = 4\\frac{M}{M_{p}^2}} = \\infty: 3.23 : 2.6$. Which is exactly \\emph{similar} to the spherically symmetric extreme Reissner-Nordstr\\"{o}m black hole.}

  3. Inference on accretion flow dynamics using TCAF solution from the analysis of spectral evolution of H 1743-322 during 2010 outburst

    E-Print Network [OSTI]

    Mondal, Santanu; Chakrabarti, Sandip K

    2014-01-01

    We study accretion flow dynamics of Galactic transient black hole candidate (BHC) H 1743-322 during its 2010 outburst by analyzing spectral data using Two Component (Keplerian and sub-Keplerian) Advective Flow (TCAF) solution, after its inclusion in XSPEC as a local model. We compare our TCAF solution fitted results with combined disk black body and power-law model fitted results and find a similar smooth variation of thermal (Keplerian or disk black body) and non-thermal (power-law or sub-Keplerian) fluxes/rates in two types of model fits. For a spectral analysis, 2.5-25 keV spectral data from RXTE PCA instrument are used. From the TCAF solution fit, accretion flow parameters, such as Keplerian rate, sub-Keplerian rate, location of centrifugal pressure supported shock and strength of the shock are extracted, thus providing a deeper understanding of accretion process and properties of accretion disks around BHC H 1743-322 during its X-ray outburst. Based on the halo to disk accretion rate ratio (ARR), shock p...

  4. Flow dynamics of the Moon

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2010-04-03

    Flow analysis of big basins is given. Internal structure of flows is considered. Correlations between flows are calculated. For example, Mare Orientale is a moving basin. Orientale and Imbrium continental basins are introduced and are considered. Olbers ray crater is a result of precise interaction of the two basins. Flows of the Tycho type are studied. Two Antarctidae, an Indian Ocean, and an America are demonstrated.

  5. Coupled flow and geomechanical analysis for gas production in the Prudhoe Bay Unit L-106 well Unit C gas hydrate deposit in Alaska

    E-Print Network [OSTI]

    Kim, J.

    2014-01-01

    way Coupled Fluid Flow and Geomechanics in Hydrate Deposits.for Coupled Flow and Geomechanics. Soc. Pet. Eng. J. 16(2):for coupled flow and geomechanics: Drained and undrained

  6. Analysis of mass loss of a coal particle during the course of burning in a flow of inert material

    SciTech Connect (OSTI)

    Pelka, Piotr

    2009-08-15

    This paper is an attempt to explain the role of erosion during the process of coal combustion in a circulating fluidized bed. Different kinds of carbon deposits found in Poland, both bituminous as well as lignite with the particle of 10 mm in diameter were the subject of the research. According to many publications it is well known that erosion plays a significant role in coal combustion, by changing its mechanism as well as generating an additional mass loss of the mother particle. The purpose of this research was to determine the influence of an inert material on an erosive mass loss of a single coal particle burning in a two-phase flow. The determination of the influence of a coal type, the rate of flow of inert material and the temperature inside the furnace on the erosive mass loss of burning coal particle was also taken into consideration. The results obtained indicate that the velocity of the erosive mass loss depends on the chemical composition and petrographic structure of burning coal. The mechanical interaction of inert and burning coal particles leads to the shortening of the period of overall mass loss of the coal particle by even two times. The increase in the rate of flow of the inert material intensifies the generation of mass loss by up to 100%. The drop in temperature which slows down the combustion process, decreases the mass loss of the coal particle as the result of mechanical interaction of the inert material. As was observed, the process of percolation plays a significant role by weakening the surface of the burning coal. (author)

  7. Tidal energy effects of dark matter halos on early-type galaxies

    E-Print Network [OSTI]

    Valentinuzzi, T; D'Onofrio, M

    2010-01-01

    Tidal interactions between neighboring objects span across the whole admissible range of lengths in nature: from, say, atoms to clusters of galaxies i.e. from micro to macrocosms. According to current cosmological theories, galaxies are embedded within massive non-baryonic dark matter (DM) halos, which affects their formation and evolution. It is therefore highly rewarding to understand the role of tidal interaction between the dark and luminous matter in galaxies. The current investigation is devoted to Early-Type Galaxies (ETGs), looking in particular at the possibility of establishing whether the tidal interaction of the DM halo with the luminous baryonic component may be at the origin of the so-called "tilt" of the Fundamental Plane (FP). The extension of the tensor virial theorem to two-component matter distributions implies the calculation of the self potential energy due to a selected subsystem, and the tidal potential energy induced by the other one. The additional assumption of homeoidally striated d...

  8. Saltwater Incursion into Micro Tidal Wetlands: Case Studies from Matagorda, Texas and Humacao, Puerto Rico 

    E-Print Network [OSTI]

    Colon, Ricardo J.

    2013-08-27

    Global climate change threatens the survival of microtidal wetlands by altering fundamental hydrological aspects such as precipitation patterns and tidal exchange. The combination of these stressors results in increased flooding period and soil...

  9. Status of Wave and Tidal Power Technologies for the United States

    SciTech Connect (OSTI)

    Musial, W.

    2008-08-01

    This paper presents the status of marine applications for renewable energy as of 2008 from a U.S. perspective. Technologies examined include wave, tidal, and ocean current energy extraction devices.

  10. Maine Project Takes Historic Step Forward in U.S. Tidal Energy...

    Energy Savers [EERE]

    contracts will be in place for 20 years -- making them the first long-term tidal energy power purchase agreements in the United States. The implications of these agreements are...

  11. Dispersion Mechanisms of a Tidal River Junction in the Sacramento–San Joaquin Delta, California

    E-Print Network [OSTI]

    Gleichauf, Karla T.; Wolfram, Phillip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-01-01

    a Tidal River Junction in the Sacramento–San Joaquin Delta,networks, such as in the Sacramento–San Joaquin River Delta,transport and fate in the Sacramento–San Joaquin delta using

  12. Microsoft Word - RM1_Tidal Turbine_NREL Bir, Lawson, Li_2011...

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

    Arctic Engineering OMAE2011 June 19-24, 20111, Rotterdam, the Netherland OMAE2011-50063 STRUCTURAL DESIGN OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE COMPOSITE BLADE ABSTRACT This...

  13. Maine Deploys First U.S. Commercial, Grid-Connected Tidal Energy...

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

    of President Obama's all-of-the-above energy strategy to create jobs and strengthen U.S. global competitiveness," said Energy Secretary Steven Chu. "The Eastport tidal energy...

  14. Preliminary analysis of the possibility of making use of part of the energy flow of zero-point radiation

    E-Print Network [OSTI]

    R. Alvargonzalez; L. S. Soto

    2008-03-07

    The energy flow of zero-point radiation is very great, but difficult to put to use. However, the observations made by Sparnaay in 1958 and by Lamoureux in 1997 reveal the possibility of making use of a very small fraction of that immense amount. This possibility is big enough for such a minute fraction to have significant importance, but such a possibility requires miniaturisation to a degree which may be unattainable. It is worth trying to achieve it, since it would open the way to interstellar travel.

  15. Measurement of the rate of stellar tidal disruption flares

    SciTech Connect (OSTI)

    Van Velzen, Sjoert

    2014-09-01

    We report an observational estimate of the rate of stellar tidal disruption flares (TDFs) in inactive galaxies based on a successful search for these events among transients in galaxies using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82). This search yielded 186 nuclear flares in galaxies, 2 of which are excellent TDF candidates. Because of the systematic nature of the search, the very large number of galaxies, the long time of observation, and the fact that non-TDFs were excluded without resorting to assumptions about TDF characteristics, this study provides an unparalleled opportunity to measure the TDF rate. To compute the rate of optical stellar tidal disruption events, we simulate our entire pipeline to obtain the efficiency of detection. The rate depends on the light curves of TDFs, which are presently still poorly constrained. Using only the observed part of the SDSS light curves gives a model-independent upper limit to the optical TDF rate, N-dot <2×10{sup ?4} yr{sup ?1} galaxy{sup ?1} (90% CL), under the assumption that the SDSS TDFs are representative examples. We develop three empirical models of the light curves based on the two SDSS light curves and two more recent and better-sampled Pan-STARRS TDF light curves, leading to our best estimate of the rate: N-dot {sub TDF}=(1.5--2.0){sub ?1.3}{sup +2.7}×10{sup ?5} yr{sup ?1} galaxy{sup ?1}. We explore the modeling uncertainties by considering two theoretically motivated light curve models, as well as two different relationships between black hole mass and galaxy luminosity, and two different treatments of the cutoff in the visibility of TDFs at large M {sub BH}. From this we conclude that these sources of uncertainty are not significantly larger than the statistical ones. Our results are applicable for galaxies hosting black holes with mass in the range of a few 10{sup 6}-10{sup 8} M {sub ?}, and translates to a volumetric TDF rate of (4-8) × 10{sup –8±0.4} yr{sup –1} Mpc{sup –3}, with the statistical uncertainty in the exponent.

  16. Characterization of GX 339-4 outburst of 2010-11: Analysis by XSPEC using Two Component Advective Flow model

    E-Print Network [OSTI]

    Debnath, Dipak; Chakrabarti, Sandip K

    2013-01-01

    We study the spectral properties of the Galactic transient black hole candidate (BHC) GX 339-4 during its 2010-11 outburst with Two Component (Keplerian and sub-Keplerian) Advective Flow (TCAF) model after its inclusion in XSPEC as a local model. We also compare our TCAF model fitted results with combined disk black body (DBB) and power-law (PL) model fitted spectral results and find similar types of smooth variation in thermal (Keplerian or disk black body) as well as non-thermal (power-law or sub-Keplerian) fluxes. For spectral fit, we use 2.5-25 keV spectral data of PCA instrument onboard RXTE satellite. From the TCAF model fit, accretion flow parameters, such as the Keplerian (disk) rate, sub-Keplerian (halo) rate, location of the shock and strength of the shock are extracted. Our study provides a comprehensive understanding of the mass accretion processes and properties of the accretion disk around the BHC during the outburst phases. Based on the comparison of the halo to disk accretion rate ratio (ARR) ...

  17. PWR FLECHT SEASET 21-rod-bundle flow-blockage task: data and analysis report. NRC/EPRI/Westinghouse report No. 11, main report and appendices A-J

    SciTech Connect (OSTI)

    Loftus, M.J.; Hochreiter, L.E.; Lee, N.; McGuire, M.F.; Wenzel, A.H.; Valkovic, M.M.

    1982-09-01

    This report presents data and limited analysis from the 21-Rod Bundle Flow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Separate Effects and Systems Effects Test Program (FLECHT SEASET). The tests consisted of forced and gravity reflooding tests utilizing electrical heater rods with a cosine axial power profile to simulate PWR nuclear core fuel rod arrays. Steam cooling and hydraulic characteristics tests were also conducted. These tests were utilized to determine effects of various flow blockage configurations (shapes and distributions) on reflooding behavior, to aid in development/assessment of computational models in predicting reflooding behavior of flow blockage configurations, and to screen flow blockage configurations for future 163-rod flow blockage bundle tests.

  18. A Modeling Study of the Potential Water Quality Impacts from In-Stream Tidal Energy Extraction

    SciTech Connect (OSTI)

    Wang, Taiping; Yang, Zhaoqing; Copping, Andrea E.

    2013-11-09

    To assess the effects of tidal energy extraction on water quality in a simplified estuarine system, which consists of a tidal bay connected to the coastal ocean through a narrow channel where energy is extracted using in-stream tidal turbines, a three-dimensional coastal ocean model with built-in tidal turbine and water quality modules was applied. The effects of tidal energy extraction on water quality were examined for two energy extraction scenarios as compared with the baseline condition. It was found, in general, that the environmental impacts associated with energy extraction depend highly on the amount of power extracted from the system. Model results indicate that, as a result of energy extraction from the channel, the competition between decreased flushing rates in the bay and increased vertical mixing in the channel directly affects water quality responses in the bay. The decreased flushing rates tend to cause a stronger but negative impact on water quality. On the other hand, the increase of vertical mixing could lead to higher bottom dissolved oxygen at times. As the first modeling effort directly aimed at examining the impacts of tidal energy extraction on estuarine water quality, this study demonstrates that numerical models can serve as a very useful tool for this purpose. However, more careful efforts are warranted to address system-specific environmental issues in real-world, complex estuarine systems.

  19. Gravitational self-force corrections to two-body tidal interactions and the effective one-body formalism

    E-Print Network [OSTI]

    Donato Bini; Thibault Damour

    2014-09-24

    Tidal interactions have a significant influence on the late dynamics of compact binary systems, which constitute the prime targets of the upcoming network of gravitational-wave detectors. We refine the theoretical description of tidal interactions (hitherto known only to the second post-Newtonian level) by extending our recently developed analytic self-force formalism, for extreme mass-ratio binary systems, to the computation of several tidal invariants. Specifically, we compute, to linear order in the mass ratio and to the 7.5$^{\\rm th}$ post-Newtonian order, the following tidal invariants: the square and the cube of the gravitoelectric quadrupolar tidal tensor, the square of the gravitomagnetic quadrupolar tidal tensor, and the square of the gravitoelectric octupolar tidal tensor. Our high-accuracy analytic results are compared to recent numerical self-force tidal data by Dolan et al. \\cite{Dolan:2014pja}, and, notably, provide an analytic understanding of the light ring asymptotic behavior found by them. We transcribe our kinematical tidal-invariant results in the more dynamically significant effective one-body description of the tidal interaction energy. By combining, in a synergetic manner, analytical and numerical results, we provide simple, accurate analytic representations of the global, strong-field behavior of the gravitoelectric quadrupolar tidal factor. A striking finding is that the linear-in-mass-ratio piece in the latter tidal factor changes sign in the strong-field domain, to become negative (while its previously known second post-Newtonian approximant was always positive). We, however, argue that this will be more than compensated by a probable fast growth, in the strong-field domain, of the nonlinear-in-mass-ratio contributions in the tidal factor.

  20. EVIDENCE FOR A MILKY WAY TIDAL STREAM REACHING BEYOND 100 kpc

    SciTech Connect (OSTI)

    Drake, A. J.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A.; Donalek, C.; Williams, R. [California Institute of Technology, 1200 E. California Blvd., CA 91225 (United States); Catelan, M.; Torrealba, G. [Pontificia Universidad Catolica de Chile, Departamento de Astronomia y Astrofisica, Facultad de Fisica, Av. Vicuna Mackena 4860, 782-0436 Macul, Santiago (Chile); Prieto, J. L. [Department of Astronomy, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Larson, S.; Christensen, E.; Beshore, E. [Department of Planetary Sciences, University of Arizona, Lunar and Planetary Laboratory, 1629 E. University Blvd., Tucson AZ 85721 (United States)

    2013-03-10

    We present the analysis of 1207 RR Lyrae found in photometry taken by the Catalina Survey's Mount Lemmon telescope. By combining accurate distances for these stars with measurements for {approx}14,000 type-ab RR Lyrae from the Catalina Schmidt telescope, we reveal an extended association that reaches Galactocentric distances beyond 100 kpc and overlaps the Sagittarius stream system. This result confirms earlier evidence for the existence of an outer halo tidal stream resulting from a disrupted stellar system. By comparing the RR Lyrae source density with that expected based on halo models, we find the detection has {approx}8{sigma} significance. We investigate the distances, radial velocities, metallicities, and period-amplitude distribution of the RR Lyrae. We find that both radial velocities and distances are inconsistent with current models of the Sagittarius stream. We also find tentative evidence for a division in source metallicities for the most distant sources. Following prior analyses, we compare the locations and distances of the RR Lyrae with photometrically selected candidate horizontal branch stars and find supporting evidence that this structure spans at least 60 Degree-Sign of the sky. We investigate the prospects of an association between the stream and the unusual globular cluster NGC 2419.

  1. Spitzer View of Massive Star Formation in the Tidally Stripped Magellanic Bridge

    E-Print Network [OSTI]

    Chen, C -H Rosie; Muller, Erik; Kawamura, Akiko; Gordon, Karl D; Sewi?o, Marta; Whitney, Barbara A; Fukui, Yasuo; Madden, Suzanne C; Meade, Marilyn R; Meixner, Margaret; Oliveira, Joana M; Robitaille, Thomas P; Seale, Jonathan P; Shiao, Bernie; van Loon, Jacco Th

    2014-01-01

    The Magellanic Bridge is the nearest low-metallicity, tidally stripped environment, offering a unique high-resolution view of physical conditions in merging and forming galaxies. In this paper we present analysis of candidate massive young stellar objects (YSOs), i.e., {\\it in situ, current} massive star formation (MSF) in the Bridge using {\\it Spitzer} mid-IR and complementary optical and near-IR photometry. While we definitely find YSOs in the Bridge, the most massive are $\\sim10 M_\\odot$, $\\ll45 M_\\odot$ found in the Large Magellanic Cloud (LMC). The intensity of MSF in the Bridge also appears decreasing, as the most massive YSOs are less massive than those formed in the past. To investigate environmental effects on MSF, we have compared properties of massive YSOs in the Bridge to those in the LMC. First, YSOs in the Bridge are apparently less embedded than in the LMC: 81% of Bridge YSOs show optical counterparts, compared to only 56% of LMC sources with the same range of mass, circumstellar dust mass, and...

  2. Tidal Downsizing Model. IV. Destructive feedback in planets

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01

    I argue that feedback is as important to formation of planets as it is to formation of stars and galaxies. Energy released by massive solid cores puffs up pre-collapse gas giant planets, making them vulnerable to tidal disruptions by their host stars. I find that feedback is the ultimate reason for some of the most robust properties of the observed exoplanet populations: the rarity of gas giants at all separations from $\\sim 0.1$ to $\\sim 100$~AU, the abundance of $\\sim 10 M_\\oplus$ cores but dearth of planets more massive than $\\sim 20 M_\\oplus$. Feedback effects can also explain (i) rapid assembly of massive cores at large separations as needed for Uranus, Neptune and the suspected HL Tau planets; (ii) the small core in Jupiter yet large cores in Uranus and Neptune; (iii) the existence of rare "metal monster" planets such as CoRoT-20b, a gas giant made of heavy elements by up to $\\sim 50$\\%.

  3. WATER TRAPPING ON TIDALLY LOCKED TERRESTRIAL PLANETS REQUIRES SPECIAL CONDITIONS

    SciTech Connect (OSTI)

    Yang, Jun; Abbot, Dorian S.; Liu, Yonggang; Hu, Yongyun

    2014-12-01

    Surface liquid water is essential for standard planetary habitability. Calculations of atmospheric circulation on tidally locked planets around M stars suggest that this peculiar orbital configuration lends itself to the trapping of large amounts of water in kilometers-thick ice on the night side, potentially removing all liquid water from the day side where photosynthesis is possible. We study this problem using a global climate model including coupled atmosphere, ocean, land, and sea ice components as well as a continental ice sheet model driven by the climate model output. For a waterworld, we find that surface winds transport sea ice toward the day side and the ocean carries heat toward the night side. As a result, nightside sea ice remains O(10 m) thick and nightside water trapping is insignificant. If a planet has large continents on its night side, they can grow ice sheets O(1000 m) thick if the geothermal heat flux is similar to Earth's or smaller. Planets with a water complement similar to Earth's would therefore experience a large decrease in sea level when plate tectonics drives their continents onto the night side, but would not experience complete dayside dessiccation. Only planets with a geothermal heat flux lower than Earth's, much of their surface covered by continents, and a surface water reservoir O(10%) of Earth's would be susceptible to complete water trapping.

  4. Jet and disk luminosities in tidal disruption events

    E-Print Network [OSTI]

    Piran, Tsvi; Tchekhovskoy, Alexander

    2015-01-01

    Tidal disruption events (TDE) in which a star is devoured by a massive black hole at a galac- tic center pose a challenge to our understanding of accretion processes. Within a month the accretion rate reaches super-Eddington levels. It then drops gradually over a time scale of a year to sub-Eddington regimes. The initially geometrically thick disk becomes a thin one and eventually an ADAF at very low accretion rates. As such, TDEs explore the whole range of accretion rates and configurations. A challenging question is what the corresponding light curves of these events are. We explore numerically the disk luminosity and the conditions within the inner region of the disk using a fully general relativistic slim disk model. Those conditions determine the magnitude of the magnetic field that engulfs the black hole and this, in turn, determines the Blandford-Znajek jet power. We estimate this power in two different ways and show that they are self-consistent. We find, as expected earlier from analytic argu- ments ...

  5. SKA as a powerful hunter of jetted Tidal Disruption Events

    E-Print Network [OSTI]

    Donnarumma, I; Fender, R; Komossa, S; Paragi, Z; Van Velzen, S; Prandoni, I

    2015-01-01

    Observational consequences of the tidal disruption of stars by supermassive black holes (SMBHs) can enable us to discover quiescent SMBHs and constrain their mass function. Moreover, observing jetted TDEs (from previously non-active galaxies) provides us with a new means of studying the early phases of jet formation and evolution in an otherwise "pristine" environment. Although several (tens) TDEs have been discovered since 1999, only two jetted TDEs have been recently discovered in hard X-rays, and only one, Swift J1644+57, has a precise localization which further supports the TDE interpretation. These events alone are not sufficient to address those science issues, which require a substantial increase of the current sample. Despite the way they were discovered, the highest discovery potential for {\\em jetted} TDEs is not held by current and up-coming X-ray instruments, which will yield only a few to a few tens events per year. In fact, the best strategy is to use the Square Kilometer Array to detect TDEs an...

  6. Tidal Accelerometry: Exploring the Cosmos Via Gravitational Correlations

    E-Print Network [OSTI]

    Datta, Timir; Wescott, Mike; Jeong, Yeuncheol; Morawiec, Pawel; Gambrell, James; Overcash, Dan; Zhang, Huaizhou; Voulgaris, George

    2010-01-01

    Newtonian gravitation is non-radiative but is extremely pervasive and penetrates equally into every media because it cannot be shielded. The extra terrestrial fgravity is responsible for earth's trajectory. However its correlation or geodesic deviation is manifested as semi-diurnal and diurnal tides. Tidal signals, A(t) are temporal modulations in the field differential which can be observed in a wide variety of natural and laboratory situations. A(t) is a quasi-static, low frequency signal which arises from the relative changes in positions of the detector and source and is not part of the electromagnetic spectrum. Isaac Newton was the first to recognize the importance of tides in astrometry and attempetd to estimate lunar mass from ocean tides. By a case study we show, how the systematics of the gravitational correlation can be used for calibration and de-trending which can significantly increase the confidence level of high precision experiments. A(t) can also be used to determine the distribution of celes...

  7. Scaling laws to understand tidal dissipation in fluid planetary regions and stars I - Rotation, stratification and thermal diffusivity

    E-Print Network [OSTI]

    Auclair-Desrotour, P; Poncin-Lafitte, C Le

    2015-01-01

    Tidal dissipation in planets and stars is one of the key physical mechanisms driving the evolution of star-planet and planet-moon systems. Several signatures of its action are observed in planetary systems thanks to their orbital architecture and the rotational state of their components. Tidal dissipation inside the fluid layers of celestial bodies are intrinsically linked to the dynamics and the physical properties of the latter. This complex dependence must be characterized. We compute the tidal kinetic energy dissipated by viscous friction and thermal diffusion in a rotating local fluid Cartesian section of a star/planet/moon submitted to a periodic tidal forcing. The properties of tidal gravito-inertial waves excited by the perturbation are derived analytically as explicit functions of the tidal frequency and local fluid parameters (i.e. the rotation, the buoyancy frequency characterizing the entropy stratification, viscous and thermal diffusivities) for periodic normal modes. The sensitivity of the resul...

  8. Subtropical catastrophe: Significant loss of low-mode tidal energy at J. A. MacKinnon and K. B. Winters

    E-Print Network [OSTI]

    MacKinnon, Jennifer

    Subtropical catastrophe: Significant loss of low-mode tidal energy at 28.9°° J. A. MacKinnon and K with a northward baroclinic tidal flux of approximately 1.7 kW/m. After an initial spinup period, energy is quickly of low-mode tidal energy at 28.9°, Geophys. Res. Lett., 32, L15605, doi:10.1029/ 2005GL023376. 1

  9. Two-and three-dimensional double-sandbar system behaviour under intense wave forcing and a mesomacro tidal range

    E-Print Network [OSTI]

    ­macro tidal range R. Almar a,b,Ã, B. Castelle a,b , B.G. Ruessink c , N. Se´ne´chal a,b , P. Bonneton a,b , V­macro tidal environment Storm impact Nearshore Video imaging Short-term morphodynamics Truc Vert Beach a b s t r a c t Five weeks of hourly, 10-min time-exposure video images were used to analyze the meso­macro-tidal

  10. Cosmic Flows: A Status Report

    E-Print Network [OSTI]

    Stephane Courteau; Avishai Dekel

    2001-06-03

    We give a brief review of recent developments in the study of the large-scale velocity field of galaxies since the international workshop on Cosmic Flows held in July 1999 in Victoria, B.C. Peculiar velocities (PVs) yield a tight and unique constraint on cosmological characteristics, independent of Lambda and biasing, such as the cosmological matter density parameter Omega_m and the convergence of bulk flows on large scales. Significant progress towards incorporating non-linear dynamics and improvements of velocity field reconstruction techniques have led to a rigorous control of errors and much refined cosmic flow analyses. Current investigations favor low-amplitude (< 250 km/s) bulk flows on the largest scales (< ~100 Mpc/h) probed reliably by existing redshift-distance surveys, consistent with favored LambdaCDM cosmogonies. Tidal field analyses also suggest that the Shapley Concentration, located behind the Great Attractor (GA), might play an important dynamical role, even at the Local Group. Low-amplitude density fluctuations on very large scales generate the overall large-scale streaming motions while massive attractors like the GA, and Perseus-Pisces account for smaller scale motions which are superposed on the large-scale flow. Likelihood analyses of galaxy PVs, in the framework of flat CDM cosmology, now provide tight constraints of Omega_m = 0.35 +/- 0.05. A four-fold size increase of our data base is expected in the next 4-5 years with the completion of next generation FP/TF surveys and automated supernovae searches within 20,000 km/s.

  11. Post-rehabilitation flow monitoring and analysis of the sanitary sewer system at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Brandstetter, E.R.; Littlefield, D.C.; Villegas, M.

    1996-03-01

    Lawrence Livermore National Laboratory (LLNL) is operated by the University of California under contract with the U.S. Department of Energy (DOE). The Livermore site, approximately 50 miles southeast of San Francisco, occupies 819 acres. So far, there have been three phases in an assessment and rehabilitation of the LLNL sanitary sewer system. A 1989 study that used data collected from December 1, 1988, to January 6, 1989, to determine the adequacy of the LLNL sewer system to accommodate present and future peak flows. A Sanitary Sewer Rehabilitation (SSR) project, from October of 1991 to March of 1996, in which the system was assessed and rehabilitated. The third study is the post-rehabilitation assessment study that is reported in this document. In this report, the sanitary sewer system is described, and the goals and results of the 1989 study and the SSR project are summarized. The goals of the post-rehabilitation study are given and the analytical procedures and simulation model are described. Results, conclusions, and recommendations for further work or study are given. Field operations are summarized in Appendix A. References are provided in Appendix B.

  12. Optimization and Analysis of High-Power Hydrogen/Bromine-Flow Batteries for Grid-Scale Energy Storage

    SciTech Connect (OSTI)

    Cho, KT; Albertus, P; Battaglia, V; Kojic, A; Srinivasan, V; Weber, AZ

    2013-10-07

    For storage of grid-scale electrical energy, redox-flow batteries (RFBs) are considered promising technologies. This paper explores the influence of electrolyte composition and ion transport on cell performance by using an integrated approach of experiments and cost modeling. In particular, the impact of the area-specific resistance on system capability is elucidated for the hydrogen/bromine RFB. The experimental data demonstrate very good performance with 1.46 W cm(-2) peak power and 4 A cm(-2) limiting current density at ambient conditions for an optimal cell design and reactant concentrations. The data and cost model results show that higher concentrations of RFB reactants do not necessarily result in lower capital cost as there is a tradeoff between cell performance and storage (tank) requirements. In addition, the discharge time and overall efficiency demonstrate nonlinear effects on system cost, with a 3 to 4 hour minimum discharge time showing a key transition to a plateau in terms of cost for typical RFB systems. The presented results are applicable to many different RFB chemistries and technologies and highlight the importance of ohmic effects and associated area-specific resistance on RFB viability.

  13. Flow chamber

    DOE Patents [OSTI]

    Morozov, Victor (Manassas, VA)

    2011-01-18

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

  14. In-situ Condition Monitoring of Components in Small Modular Reactors Using Process and Electrical Signature Analysis. Final report, volume 1. Development of experimental flow control loop, data analysis and plant monitoring

    SciTech Connect (OSTI)

    Upadhyaya, Belle; Hines, J. Wesley; Damiano, Brian; Mehta, Chaitanya; Collins, Price; Lish, Matthew; Cady, Brian; Lollar, Victor; de Wet, Dane; Bayram, Duygu

    2015-12-15

    The research and development under this project was focused on the following three major objectives: Objective 1: Identification of critical in-vessel SMR components for remote monitoring and development of their low-order dynamic models, along with a simulation model of an integral pressurized water reactor (iPWR). Objective 2: Development of an experimental flow control loop with motor-driven valves and pumps, incorporating data acquisition and on-line monitoring interface. Objective 3: Development of stationary and transient signal processing methods for electrical signatures, machinery vibration, and for characterizing process variables for equipment monitoring. This objective includes the development of a data analysis toolbox. The following is a summary of the technical accomplishments under this project: - A detailed literature review of various SMR types and electrical signature analysis of motor-driven systems was completed. A bibliography of literature is provided at the end of this report. Assistance was provided by ORNL in identifying some key references. - A review of literature on pump-motor modeling and digital signal processing methods was performed. - An existing flow control loop was upgraded with new instrumentation, data acquisition hardware and software. The upgrading of the experimental loop included the installation of a new submersible pump driven by a three-phase induction motor. All the sensors were calibrated before full-scale experimental runs were performed. - MATLAB-Simulink model of a three-phase induction motor and pump system was completed. The model was used to simulate normal operation and fault conditions in the motor-pump system, and to identify changes in the electrical signatures. - A simulation model of an integral PWR (iPWR) was updated and the MATLAB-Simulink model was validated for known transients. The pump-motor model was interfaced with the iPWR model for testing the impact of primary flow perturbations (upsets) on plant parameters and the pump electrical signatures. Additionally, the reactor simulation is being used to generate normal operation data and data with instrumentation faults and process anomalies. A frequency controller was interfaced with the motor power supply in order to vary the electrical supply frequency. The experimental flow control loop was used to generate operational data under varying motor performance characteristics. Coolant leakage events were simulated by varying the bypass loop flow rate. The accuracy of motor power calculation was improved by incorporating the power factor, computed from motor current and voltage in each phase of the induction motor.- A variety of experimental runs were made for steady-state and transient pump operating conditions. Process, vibration, and electrical signatures were measured using a submersible pump with variable supply frequency. High correlation was seen between motor current and pump discharge pressure signal; similar high correlation was exhibited between pump motor power and flow rate. Wide-band analysis indicated high coherence (in the frequency domain) between motor current and vibration signals. - Wide-band operational data from a PWR were acquired from AMS Corporation and used to develop time-series models, and to estimate signal spectrum and sensor time constant. All the data were from different pressure transmitters in the system, including primary and secondary loops. These signals were pre-processed using the wavelet transform for filtering both low-frequency and high-frequency bands. This technique of signal pre-processing provides minimum distortion of the data, and results in a more optimal estimation of time constants of plant sensors using time-series modeling techniques.

  15. Geological flows

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2008-11-19

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

  16. Flow regimes

    SciTech Connect (OSTI)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced.

  17. TRAC-PF1/MOD-1 analysis of Loss-Of-Flow Test L9-4

    SciTech Connect (OSTI)

    Meier, J.

    1985-01-01

    Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC) to provide advanced best-estimate predictions of postulated accidents in pressurized water reactors (PWRs) and for many thermal-hydraulic experimental facilities. As part of our independent assessment of code version TRAC-PF1/MOD1, we analyzed Loss-of-Fluid Test (LOFT) L9-4 and compared the test data to the calculated results. This was an anticipated-transient-without-scram test in which the pumps were tripped, the steam generator main feedwater discontinued, and the main steam-outlet valve closed. This data comparison is the first extensive test of TRAC's reactor-kinetics models. The comparisons show that TRAC can calculate the power generation within a nuclear reactor if the program is supplied with adequate reactor-kinetics input specifications. The data comparisons also indicate that TRAC calculated the thermal-hydraulic parameters within LOFT well with only minor discrepancies. A number of models within TRAC-PF1/MOD1 were verified for the first time. They include the reactor-kinetics models, the trip-activated time-step controls, and the LOFT pump-coastdown calculations. In general, the final input description is adequate to analyze the experiment. The calculations indicate the importance and difficulty of obtaining accurate and applicable reactor-kinetics input data. They also indicate the need to include the effects of xenon-poisoning buildup in the analysis.

  18. Petrophysical analysis of regional-scale thermal properties for improved simulations of geothermal installations and basin-scale heat and fluid flow

    E-Print Network [OSTI]

    Hartmann, Andreas; Clauser, Christoph

    2008-01-01

    Development of geothermal energy and basin-scale simulations of fluid and heat flow both suffer from uncertain physical rock properties at depth. Therefore, building better prognostic models are required. We analysed hydraulic and thermal properties of the major rock types in the Molasse Basin in Southern Germany. On about 400 samples thermal conductivity, density, porosity, and sonic velocity were measured. Here, we propose a three-step procedure with increasing complexity for analysis of the data set: First, univariate descriptive statistics provides a general understanding of the data structure, possibly still with large uncertainty. Examples show that the remaining uncertainty can be as high as 0.8 W/(m K) or as low as 0.1 W/(m K). This depends on the possibility to subdivide the geologic units into data sets that are also petrophysically similar. Then, based on all measurements, cross-plot and quick-look methods are used to gain more insight into petrophysical relationships and to refine the analysis. Be...

  19. Tidal dissipation in a homogeneous spherical body. II. Three examples: Mercury, Io, and Kepler-10 b

    SciTech Connect (OSTI)

    Makarov, Valeri V.; Efroimsky, Michael E-mail: michael.efroimsky@usno.navy.mil

    2014-11-01

    In Efroimsky and Makarov (Paper I), we derived from the first principles a formula for the tidal heating rate in a homogeneous sphere, compared it with the previously used formulae, and noted the differences. Now we present case studies: Mercury, Kepler-10 b, and a triaxial Io. A sharp frequency dependence of k {sub 2}/Q near spin-orbit resonances yields a sharp dependence of k {sub 2}/Q (and, therefore, of tidal heating) upon the spin rate. Thereby physical libration plays a major role in tidal heating of synchronously rotating planets. The magnitude of libration in the spin rate being defined by the planet's triaxiality, the latter becomes a factor determining the dissipation rate. Other parameters equal, a strongly triaxial synchronized body generates more heat than a similar body of a more symmetrical shape. After an initially triaxial object melts and loses its triaxiality, dissipation becomes less intensive; the body can solidify, with the tidal bulge becoming a new figure with triaxiality lower than the original. We derive approximate expressions for the dissipation rate in a Maxwell planet with the Maxwell time longer than the inverse tidal frequency. The expressions derived pertain to the 1:1 and 3:2 resonances and a nonresonant case; so they are applicable to most close-in super-Earths detected. In these planets, the heating outside synchronism is weakly dependent on the eccentricity and obliquity, provided both these parameters's values are moderate. According to our calculation, Kepler-10 b could hardly survive the intensive tidal heating without being synchronized, circularized, and reshaped through a complete or partial melt-down.

  20. Macroscopic traversable wormholes with zero tidal forces inspired by noncommutative geometry

    E-Print Network [OSTI]

    Peter K. F. Kuhfittig

    2015-01-08

    This paper addresses the following issues: (1) the possible existence of macroscopic traversable wormholes, given a noncommutative-geometry background, and (2) the possibility of allowing zero tidal forces, given a known density. It is shown that whenever the energy density describes a classical wormhole, the resulting solution is incompatible with quantum field theory. If the energy density originates from noncommutative geometry, then zero tidal forces are allowed. Also attributable to the noncommutative geometry is the violation of the null energy condition. The wormhole geometry satisfies the usual requirements, including asymptotic flatness.

  1. Detection of Gravitational Wave Emission by Supermassive Black Hole Binaries Through Tidal Disruption Flares

    E-Print Network [OSTI]

    Hayasaki, Kimitake

    2015-01-01

    Galaxy mergers produce binaries of supermassive black holes, which emit gravitational waves prior to their coalescence. We perform three-dimensional hydrodynamic simulations to study the tidal disruption of stars by such a binary in the final centuries of its life. We find that the gas stream of the stellar debris moves chaotically in the binary potential and forms accretion disks around both black holes. The accretion light curve is modulated over the binary orbital period owing to relativistic beaming. This periodic signal allows to detect the decay of the binary orbit due to gravitational wave emission by observing two tidal disruption events that are separated by more than a decade.

  2. MHK Projects/Homeowner Tidal Power Elec Gen | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource HistoryScenarios Towards 2050 JumpCoos Bay OPTHalf Moon Cove TidalTidal

  3. Aggradation of gravels in tidally influenced fluvial systems: upper Albian (Lower Cretaceous) on the cratonic margin of the North

    E-Print Network [OSTI]

    González, Luis A.

    Aggradation of gravels in tidally influenced fluvial systems: upper Albian (Lower Cretaceous for the required water supply flux. Regardless of temporal scale, gravels were transported during `high-energy at the mouths of the river system, and tidal effects were transmitted at least 200 km inland from

  4. Distribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation in a Tidally Driven Bottom Boundary Layer

    E-Print Network [OSTI]

    Distribution of Energy Spectra, Reynolds Stresses, Turbulence Production, and Dissipation in a Tidally Driven Bottom Boundary Layer L. LUZNIK,* R. GURKA,*, W. A. M. NIMMO SMITH,# W. ZHU,* J. KATZ) site] are examined, covering the accelerating and decelerating phases of a single tidal cycle

  5. will appear in Journal of Geophysical Research, 2001. Observations of turbulence in a tidal beam and across a coastal ridge

    E-Print Network [OSTI]

    Lien, Ren-Chieh

    1 will appear in Journal of Geophysical Research, 2001. Observations of turbulence in a tidal beam the turbulence kinetic energy dissipation rate exceeded 10-6 W kg-1 , and the diapycnal eddy diffusivity K varied by a factor of 100 with a semidiurnal tidal periodicity; the isopycnal displacement confirmed

  6. Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency radar

    E-Print Network [OSTI]

    Miami, University of

    Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency radar measured by a high-frequency (HF) radar. The Ocean Surface Current Radar (OSCR) was deployed at the U. M., and L. K. Shay, Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency

  7. Modeling shrouded stator cavity flows in axial-flow compressors

    SciTech Connect (OSTI)

    Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.

    2000-01-01

    Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.

  8. Please cite this article in press as: G. Prez, et al., Optimized mass flow rate distribution analysis for cooling the ITER Blanket System, Fusion Eng. Des. (2014), http://dx.doi.org/10.1016/j.fusengdes.2014.03.002

    E-Print Network [OSTI]

    Raffray, A. René

    2014-01-01

    analysis for cooling the ITER Blanket System, Fusion Eng. Des. (2014), http://dx.doi.org/10.1016/j.elsevier.com/locate/fusengdes Optimized mass flow rate distribution analysis for cooling the ITER Blanket System Germán Pérez , Raphaël: ITER Blanket System Mass flow rate Critical heat flux a b s t r a c t This paper presents the rationale

  9. Mechanical design of flow batteries

    E-Print Network [OSTI]

    Hopkins, Brandon J. (Brandon James)

    2013-01-01

    The purpose of this research is to investigate the design of low-cost, high-efficiency flow batteries. Researchers are searching for next-generation battery materials, and this thesis presents a systems analysis encompassing ...

  10. The Cascade of Tidal Energy from Low to High Modes on a Continental Slope SAMUEL M. KELLY* AND JONATHAN D. NASH

    E-Print Network [OSTI]

    The Cascade of Tidal Energy from Low to High Modes on a Continental Slope SAMUEL M. KELLY 25 March 2012) ABSTRACT The linear transfer of tidal energy from large to small scales is quantified. Observed transfer of tidal energy into high-mode internal tides is quantitatively consistent with observed

  11. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Dissipation at tidal and seismic frequencies in a melt-free,

    E-Print Network [OSTI]

    Nimmo, Francis

    be readily detectable with future seismological observations. 1. Introduction The rate at which tidal energyJOURNAL OF GEOPHYSICAL RESEARCH, VOL. ???, XXXX, DOI:10.1029/, Dissipation at tidal and seismic of Phobos provides a constraint on the tidal dissipation factor, Q, within Mars. We model viscoelastic

  12. A simple parameterization of turbulent tidal mixing near supercritical topography JODY M. KLYMAK1, SONYA LEGG2, AND ROBERT PINKEL3

    E-Print Network [OSTI]

    Klymak, Jody M.

    MAY 2010 1 A simple parameterization of turbulent tidal mixing near supercritical topography JODY M Jolla CA, 98105, USA (Manuscript received , in final form ) ABSTRACT A simple parameterization for tidal wave modes that have non-rotating phase speeds slower than the tidal advection speed are assumed

  13. Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM

    E-Print Network [OSTI]

    Wray, Craig

    2010-01-01

    Type of Analysis CrossFlow; ! - Heat ExchangerType of Analysis CrossFlow; ! - Heat Exchanger ConfigurationType of Analysis CrossFlow; ! - Heat Exchanger Configuration

  14. PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1

    E-Print Network [OSTI]

    Martone, Patrick T.

    PHYSIOLOGICAL PERFORMANCE OF INTERTIDAL CORALLINE ALGAE DURING A SIMULATED TIDAL CYCLE1 Rebecca J, Lobban and Harrison 1997, Helmuth and Hofmann 2001). During high tide, intertidal algae are underwater algae may be emerged and exposed to increased light stress, elevated air tem- peratures, and increased

  15. EVALUATION OF TIDAL INLETS CHANNEL MIGRATION AND MANAGEMENT PRACTICES IN SOUTHWEST FLORIDA

    E-Print Network [OSTI]

    US Army Corps of Engineers

    484 EVALUATION OF TIDAL INLETS CHANNEL MIGRATION AND MANAGEMENT PRACTICES IN SOUTHWEST FLORIDA are analyzed to understand common factors that contribute to channel migration for inlets with/without jetties depth sufficient for reliable navigation in critical shoaling areas. In addition, ebb shoals have been

  16. Radar interferometry for measuring tidal strains across cracks on David Sandwell,1

    E-Print Network [OSTI]

    Sandwell, David T.

    Radar interferometry for measuring tidal strains across cracks on Europa David Sandwell,1 Paul and the plate has been relatively thin ($2 km) [Carr et al., 1998]. However, the present-day average shell relationships and a variety of morphologic characteristics [Carr et al., 1998; Greenberg et al., 1998]. Simple

  17. TIDAL ENERGY SITE RESOURCE ASSESSMENT: TECHNICAL SPECIFICATIONS, BEST PRACTICES AND CASE STUDIES

    E-Print Network [OSTI]

    Siefert, Chris

    , Wind and Water Power Technologies, Environmental Sciences Division, Oak Ridge National Laboratory, Oak fashion, we can develop tidal energy site classes that map to standard TEC designs, similar to the wind over a representative period of record, to design the structural loading and power capacity of the TEC

  18. Tidal constituent database. West Coast of the United States and Eastern North pacific ocean. Technical note

    SciTech Connect (OSTI)

    NONE

    1995-01-01

    This technical note describes a database of tidal elevation boundary condition information generated in support of the `Long-Term Fate of Dredged Material Disposed in Open Water` research of the Dredging Research Program (DRP), being conducted at the U.S. Army Engineer Waterways Experiment Station. The database, described in detail by Hench and others (1994), allows the user to manually generate time series of tidal elevations or to use a program to access the full database to generate time series of both tidal elevations and currents for any location along the West Coast of the United States and Eastern North Pacific Ocean, extending from Seal Cape on Unimak Island, Alaska, in the North to Punta Parada, Peru, in the South. The land boundary includes the Pacific shorelines of Alaska, Canada, mainland United States, Mexico, Guatemala, El Salvador, Nicaragua, Costa Rica, Panama, Columbia, and Northern Peru. Although the capability to generate these time series was developed to provide input to the Long-Term Fate and Stability Model (LTFATE), the generated time series can be used for any application requiring tidal forcing data.

  19. The record of sea level rise by tidal sand bodies of the English Channel

    SciTech Connect (OSTI)

    Berne, S; Lericolais, G. (Ifremer, Plouzane, (France)); Lafont, F. (Universite d'Orsay (France))

    1990-05-01

    Improvements of very high resolution seismic reflection provide new information about internal structures of modern sand bodies. This allows us to reconstruct their recent history, which is related to the Holocene sea level rise. A major distinction is found between inner shelf sand bodies, dominated by autocyclic processes, and outer shelf sand bodies, where allocyclic processes are invoked to explain the apparent contradiction between internal structures and present-day dynamics. On the inner shelf, evidence of the migration of tidal dunes (sand waves) has been obtained by repeated surveys using accurate positioning systems. Major bounding surfaces are thought to result from the action of tidal current and/or from episodic storms. A rough estimation of the age of these sand bodies can be proposed. On the outer shelf, some dunes of the English Channel exhibit cross-beds indicative of a past net bed-load transport at the opposite of present days dynamics, inherited from different tidal conditions when sea level was between 20 and 40 m lower. Some large tidal sand banks (e.g., the Sark Bank near the Channel Islands) display a more complicated pattern. The upper part of the sand bank is the result of the migration of very large dunes climbing at positive angles, whereas the lower part shows major erosional surfaces, attributed to the action of storms during lower sea levels.

  20. FLORAL AND FAUNAL DIFFERENCES BETWEEN FRAGMENTED AND UNFRAGMENTED BAHAMIAN TIDAL CREEKS

    E-Print Network [OSTI]

    Langerhans, Brian

    Valentine-Rose1,7 , Julia A. Cherry1,2 , J. Jacob Culp1,3 , Kathryn E. Perez1,4 , Jeff B. Pollock1 , D, mangroves, seagrass macroalgal beds, as well as tidal creeks; Dahlgren and Marr 2004), have been identified

  1. Tidally driven ice speed variation at Helheim Glacier, Greenland, observed with terrestrial radar interferometry

    E-Print Network [OSTI]

    Holland, David

    Tidally driven ice speed variation at Helheim Glacier, Greenland, observed with terrestrial radar Space Flight Center, Greenbelt, MD, USA 4 Earth System Science Interdisciplinary Center, University is usually packed with dense ice melange. Helheim Glacier accelerated and retreated between 2000 and 2005

  2. Transformations of galaxies. III. Encounter dynamics and tidal response as functions of galaxy structure

    E-Print Network [OSTI]

    Barnes, Joshua E

    2015-01-01

    Tidal interactions between disc galaxies depend on galaxy structure, but the details of this relationship are incompletely understood. I have constructed a three-parameter grid of bulge/disc/halo models broadly consistent with $\\Lambda$CDM, and simulated an extensive series of encounters using these models. Halo mass and extent strongly influence the dynamics of orbit evolution. In close encounters, the transfer of angular momentum mediated by the dynamical response of massive, extended haloes can reverse the direction of orbital motion of the central galaxies after their first passage. Tidal response is strongly correlated with the ratio $v_\\mathrm{e} / v_\\mathrm{c}$ of escape to circular velocity within the participating discs. Moreover, the same ratio also correlates with the rate at which tidal tails are reaccreted by their galaxies of origin; consequently, merger remnants with `twin tails', such as NGC 7252, may prove hard to reproduce unless $(v_\\mathrm{e} / v_\\mathrm{c})^2 \\lesssim 5.5$. The tidal morp...

  3. TIDAL INTERACTION AS THE ORIGIN OF EARLY-TYPE DWARF GALAXIES IN GROUP ENVIRONMENTS

    SciTech Connect (OSTI)

    Paudel, Sanjaya; Ree, Chang H.

    2014-11-20

    We present a sample of dwarf galaxies that suffer ongoing disruption by the tidal forces of nearby massive galaxies. By analyzing structural and stellar population properties using the archival imaging and spectroscopic data from the Sloan Digital Sky Survey (SDSS), we find that they are likely a ''smoking gun'' example of the formation through tidal stirring of early-type dwarf galaxies (dEs) in the galaxy group environment. The inner cores of these galaxies are fairly intact and the observed light profiles are well fit by the Sérsic functions while the tidally stretched stellar halos are prominent in the outer parts. They are all located within a sky-projected distance of 50 kpc from the centers of the host galaxies and no dwarf galaxies have relative line-of-sight velocities larger than 205 km s{sup –1} to their hosts. We derive the Composite Stellar Population properties of these galaxies by fitting the SDSS optical spectra to a multiple-burst composite stellar population model. We find that these galaxies accumulate a significant fraction of stellar mass within the last 1 Gyr and contain a majority stellar population with an intermediate age of 2 to 4 Gyr. Based on this evidence, we argue that tidal stirring, particularly through the galaxy-galaxy interaction, might have an important role in the formation and evolution of dEs in the group environment where the influence of other gas stripping mechanism might be limited.

  4. Tidal wave in 102Pd: Rotating condensate of up to seven d-bosons

    E-Print Network [OSTI]

    S. Frauendorf; M. A. Caprio; J. Sun

    2012-02-08

    The yrast states of even even vibrational and transitional nuclei are inter- preted as a rotating condensate of interacting d-bosons and the corresponding semi-classical tidal wave concept. A simple experimental manifestation of the anharmonicity caused by the boson interaction is found. The interpretation is substantiated by calculations based on the Collective Model and the Cranking Model.

  5. Nekton Density Patterns in Tidal Ponds and Adjacent Wetlands Related to Pond Size and Salinity

    E-Print Network [OSTI]

    Nekton Density Patterns in Tidal Ponds and Adjacent Wetlands Related to Pond Size and Salinity pond sizes (diameter 750 m=large), and two habitat types (pond, adjacent marsh) in the Barataria Bay Estuary, Louisiana. Nekton assemblages of ponds and the adjacent marsh

  6. Covariation of coastal water temperature and microbial pollution at interannual to tidal periods

    E-Print Network [OSTI]

    Winant, Clinton D.

    Covariation of coastal water temperature and microbial pollution at interannual to tidal periods. G. Monismith (2004), Covariation of coastal water temperature and microbial pollution at interannual the relationship between water temperature and fecal pollution in the surf zone at Huntington and Newport Beach

  7. An Alternative Model for the Tidal Evolution of the Earth-Moon-Sun System

    E-Print Network [OSTI]

    Arbab I. Arbab

    2007-09-12

    We have found that the expansion of the universe has immense consequences on our local systems. We present a model based on cosmic expansion that fits well with observation. The close approach problem inflicting tidal theory is averted in this model. We have shown that the astronomical and geological changes of our local systems are of the order of Hubble constant.

  8. ORNL/TM-2011/419 Field Measurements at River and Tidal

    E-Print Network [OSTI]

    Siefert, Chris

    National Laboratory 3 Northwest National Marine Renewable Energy Center, University of Washington 4 IIHRORNL/TM-2011/419 Field Measurements at River and Tidal Current Sites for Hydrokinetic Energy Reports produced after January 1, 1996, are generally available free via the U.S. Department of Energy

  9. Research papers Assessment of coastal density gradients near a macro-tidal estuary

    E-Print Network [OSTI]

    Polton, Jeff

    Oceanography Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK a r t i c l e i n f o of a variety of factors ­ time and spatial (horizontal and vertical) scales are small, tidal currents factor, with wind forcing tending to reinforce it for wind speeds greater than 5­10 m sÀ1 . Near bed

  10. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01

    for Compact Plate-Type Heat Exchangers. ” American Institutethese conditions, plate-type heat exchangers with small flowHeatric plate-type compact heat exchanger showing multiple

  11. Acoustic Monitoring of Beluga Whale Interactions with Cook Inlet Tidal Energy Project

    SciTech Connect (OSTI)

    Worthington, Monty

    2014-02-05

    Cook Inlet, Alaska is home to some of the greatest tidal energy resources in the U.S., as well as an endangered population of beluga whales (Delphinapterus leucas). Successfully permitting and operating a tidal power project in Cook Inlet requires a biological assessment of the potential and realized effects of the physical presence and sound footprint of tidal turbines on the distribution, relative abundance, and behavior of Cook Inlet beluga whales. ORPC Alaska, working with the Project Team—LGL Alaska Research Associates, University of Alaska Anchorage, TerraSond, and Greeneridge Science—undertook the following U.S. Department of Energy (DOE) study to characterize beluga whales in Cook Inlet – Acoustic Monitoring of Beluga Whale Interactions with the Cook Inlet Tidal Energy Project (Project). ORPC Alaska, LLC, is a wholly-owned subsidiary of Ocean Renewable Power Company, LLC, (collectively, ORPC). ORPC is a global leader in the development of hydrokinetic power systems and eco-conscious projects that harness the power of ocean and river currents to create clean, predictable renewable energy. ORPC is developing a tidal energy demonstration project in Cook Inlet at East Foreland where ORPC has a Federal Energy Regulatory Commission (FERC) preliminary permit (P-13821). The Project collected baseline data to characterize pre-deployment patterns of marine mammal distribution, relative abundance, and behavior in ORPC’s proposed deployment area at East Foreland. ORPC also completed work near Fire Island where ORPC held a FERC preliminary permit (P-12679) until March 6, 2013. Passive hydroacoustic devices (previously utilized with bowhead whales in the Beaufort Sea) were adapted for study of beluga whales to determine the relative abundance of beluga whale vocalizations within the proposed deployment areas. Hydroacoustic data collected during the Project were used to characterize the ambient acoustic environment of the project site pre-deployment to inform the FERC pilot project process. The Project compared results obtained from this method to results obtained from other passive hydrophone technologies and to visual observation techniques performed simultaneously. This Final Report makes recommendations on the best practice for future data collection, for ORPC’s work in Cook Inlet specifically, and for tidal power projects in general. This Project developed a marine mammal study design and compared technologies for hydroacoustic and visual data collection with potential for broad application to future tidal and hydrokinetic projects in other geographic areas. The data collected for this Project will support the environmental assessment of future Cook Inlet tidal energy projects, including ORPC’s East Foreland Tidal Energy Project and any tidal energy developments at Fire Island. The Project’s rigorous assessment of technology and methodologies will be invaluable to the hydrokinetic industry for developing projects in an environmentally sound and sustainable way for areas with high marine mammal activity or endangered populations. By combining several different sampling methods this Project will also contribute to the future preparation of a comprehensive biological assessment of ORPC’s projects in Cook Inlet.

  12. Flow cytometer

    DOE Patents [OSTI]

    Van den Engh, G.

    1995-11-07

    A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.

  13. Development of a three-dimensional particle image velocimetry algorithm and analysis of synthetic and experimental flows in three-dimensions 

    E-Print Network [OSTI]

    Costes, Sylvain Vincent

    1994-01-01

    This study concerns with the development of a simple three-dimensional technique to determine the velocity of fluid by tracing the motion of seeded particles in a flow in three-dimensions. A correction for light refraction ...

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

    E-Print Network [OSTI]

    Yang, Daegil

    2013-07-15

    A growing demand for more detailed modeling of subsurface physics as ever more challenging reservoirs - often unconventional, with significant geomechanical particularities - become production targets has moti-vated research in coupled flow...

  15. Tidal Disruption Flares as the Source of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Glennys R. Farrar

    2012-10-03

    The optical spectral energy distributions of two tidal disruption flares identified by van Velzen et al. (2011) in archival SDSS data, are found to be well-fit by a thin-accretion-disk model. Furthermore, the inferred Supermassive Black Hole mass values agree well with the SMBH masses estimated from the host galaxy properties. Integrating the model SEDs to include shorter wavelength contributions provides an estimate of the bolometric luminosities of the accretion disks. The resultant bolometric luminosities are well in excess of the minimum required for accelerating UHECR protons. In combination with the recent observational estimate of the TDF rate (van Velzen and Farrar, these Proceedings), the results presented here strengthen the case that transient jets formed in tidal disruption events may be responsible for accelerating all or most UHECRs.

  16. The X-ray through Optical Fluxes and Line Strengths of Tidal Disruption Events

    E-Print Network [OSTI]

    Roth, Nathaniel; Guillochon, James; Ramirez-Ruiz, Enrico

    2015-01-01

    Observations of luminous flares resulting from the possible tidal disruption of stars by supermassive black holes have raised a number of puzzles. Outstanding questions include the origin of the optical and ultraviolet (UV) flux, the weakness of hydrogen lines in the spectrum, and the occasional simultaneous observation of x-rays. Here we study the emission from tidal disruption events (TDEs) produced as radiation from black hole accretion propagates through an extended, optically thick envelope formed from stellar debris. We analytically describe key physics controlling spectrum formation, and present detailed radiative transfer calculations that model the spectral energy distribution (SED) and optical line strengths of TDEs near peak brightness. The steady-state transfer is coupled to a non local thermodynamic equilibrium treatment of the excitation and ionization states of hydrogen, helium and oxygen (as a representative metal). Our calculations show how an extended envelope can reprocess a fraction of sof...

  17. Tidal Disruption Flares as the Source of Ultra-high Energy Cosmic Rays

    E-Print Network [OSTI]

    Farrar, Glennys R

    2012-01-01

    The optical spectral energy distributions of two tidal disruption flares identified by van Velzen et al. (2011) in archival SDSS data, are found to be well-fit by a thin-accretion-disk model. Furthermore, the inferred Supermassive Black Hole mass values agree well with the SMBH masses estimated from the host galaxy properties. Integrating the model SEDs to include shorter wavelength contributions provides an estimate of the bolometric luminosities of the accretion disks. The resultant bolometric luminosities are well in excess of the minimum required for accelerating UHECR protons. In combination with the recent observational estimate of the TDF rate (van Velzen and Farrar, these Proceedings), the results presented here strengthen the case that transient jets formed in tidal disruption events may be responsible for accelerating all or most UHECRs.

  18. CONSTRAINING TIDAL DISSIPATION IN STARS FROM THE DESTRUCTION RATES OF EXOPLANETS

    SciTech Connect (OSTI)

    Penev, Kaloyan; Jackson, Brian; Spada, Federico; Thom, Nicole

    2012-06-01

    We use the distribution of extrasolar planets in circular orbits around stars with surface convective zones detected by ground-based transit searches to constrain how efficiently tides raised by the planet are dissipated on the parent star. We parameterize this efficiency as a tidal quality factor (Q{sub *}). We conclude that the population of currently known planets is inconsistent with Q{sub *} < 10{sup 7} at the 99% level. Previous studies show that values of Q{sub *} between 10{sup 5} and 10{sup 7} are required in order to explain the orbital circularization of main-sequence low-mass binary stars in clusters, suggesting that different dissipation mechanisms might be acting in the two cases, most likely due to the very different tidal forcing frequencies relative to the stellar rotation frequency occurring for star-star versus planet-star systems.

  19. Non-linear evolution of the angular momentum of protostructures from tidal torques

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1996-04-15

    We discuss the non-linear evolution of the angular momentum L acquired by protostructures, like protogalaxies and protoclusters, due to tidal interactions with the surrounding matter inhomogeneities. The primordial density distribution is assumed to be Gaussian and the non-linear dynamics of the collisionless mass fluid is followed using Lagrangian perturbation theory. For a Cold Dark Matter spectrum, the inclusion of the leading-order Lagrangian correction terms results in a value of the rms ensemble average ^{1/2} which is only a factor of 1.3 higher than the corresponding linear estimate, irrespective of the scale. Consequently, the predictions of linear theory are rather accurate in quantifying the evolution of the angular momentum of protostructures before collapse sets in. In the Einstein-de Sitter universe, the initial torque is a good estimate for the tidal torque over the whole period during which the object is spun up.

  20. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01

    Transient Thermal, Hydraulic, and Mechanical Analysis of a2009 Transient Thermal, Hydraulic, and Mechanical AnalysisAbstract Transient Thermal, Hydraulic, and Mechanical Stress