Sample records for tidal analysis flow

  1. Extreme Value Analysis of Tidal Stream Velocity Perturbations

    SciTech Connect (OSTI)

    Harding, Samuel; Thomson, Jim; Polagye, Brian; Richmond, Marshall C.; Durgesh, Vibhav; Bryden, Ian

    2011-04-26T23:59:59.000Z

    This paper presents a statistical extreme value analysis of maximum velocity perturbations from the mean flow speed in a tidal stream. This study was performed using tidal velocity data measured using both an Acoustic Doppler Velocimeter (ADV) and an Acoustic Doppler Current Profiler (ADCP) at the same location which allows for direct comparison of predictions. The extreme value analysis implements of a Peak-Over-Threshold method to explore the effect of perturbation length and time scale on the magnitude of a 50-year perturbation.

  2. Active Flow Control on Bidirectional Rotors for Tidal MHK Applications

    SciTech Connect (OSTI)

    Shiu, Henry [Research Engineer; van Dam, Cornelis P. [Professor

    2013-08-22T23:59:59.000Z

    A marine and hydrokinetic (MHK) tidal turbine extracts energy from tidal currents, providing clean, sustainable electricity generation. In general, all MHK conversion technologies are confronted with significant operational hurdles, resulting in both increased capital and operations and maintenance (O&M) costs. To counter these high costs while maintaining reliability, MHK turbine designs can be simplified. Prior study found that a tidal turbine could be cost-effectively simplified by removing blade pitch and rotor/nacelle yaw. Its rotor would run in one direction during ebb and then reverse direction when the current switched to flood. We dubbed such a turbine a bidirectional rotor tidal turbine (BRTT). The bidirectional hydrofoils of a BRTT are less efficient than conventional hydrofoils and capture less energy, but the elimination of the pitch and yaw systems were estimated to reduce levelized cost of energy by 7.8%-9.6%. In this study, we investigated two mechanisms for recapturing some of the performance shortfall of the BRTT. First, we developed a novel set of hydrofoils, designated the yy series, for BRTT application. Second, we investigated the use of active flow control via microtabs. Microtabs are small deployable/retractable tabs, typically located near the leading or trailing edge of an air/hydrofoil with height on the order of the boundary layer thickness (1% - 2% of chord). They deploy approximately perpendicularly to the foil surface and, like gurney flaps and plain flaps, globally affect the aerodynamics of the airfoil. By strategically placing microtabs and selectively deploying them based on the direction of the inflow, performance of a BRTT rotor can be improved while retaining bidirectional operation. The yy foils were computationally designed and analyzed. They exhibited better performance than the baseline bidirectional foil, the ellipse. For example, the yyb07cn-180 had 14.7% higher (l/d)max than an ellipse of equal thickness. The yyb07cn family also had higher c{sub p,min} than equivalently thick ellipses, indicating less susceptibility to cavitation. Microtabs applied on yy foils demonstrated improved energy capture. A series of variable speed and constant speed rotors were developed with the yyb07cn family of hydrofoils. The constant speed yyb07cn rotor (yy-B02-Rcs,opt) captured 0.45% more energy than the equivalent rotor with ellipses (e-B02-Rcs,opt). With microtabs deployed (yy?t-B02-Rcs,opt), the energy capture increase over the rotor with ellipses was 1.05%. Note, however, that microtabs must be applied judiciously to bidirectional foils. On the 18% thick ellipse, performance decreased with the addition of microtabs. Details of hydrofoil performance, microtab sizing and positioning, rotor configurations, and revenue impacts are presented herein.

  3. Interactions Between Tidal Flows and Ooid Shoals, Northern Bahamas

    E-Print Network [OSTI]

    Reeder, Stacy Lynn; Rankey, Gene C.

    2008-03-01T23:59:59.000Z

    active sand waves and ripples. Towards the platform margin, tidal currents pass through narrow inlets. The main inlet opening oceanward (NW) of the shoal stretches between two Pleistocene bedrock islands, connected by a bedrock high that extends... include both flood and ebb tidal deltas, with generally lobate forms, convex away from the islands, and with endpoints at the inlets. Although the inner portions of these lobes are mainly seagrass-stabilized muddy peloidal and skeletal sands with local...

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

    E-Print Network [OSTI]

    Pringle, James "Jamie"

    on the flood tide creates enhanced vertical mixing, and resuspension of sinking particles higher into the water retards the tidal flow near the bottom, this leads to a net horizontal transport toward the less]. To a large extent these larvae are at the mercy of the prevailing currents, often leading to a strong

  5. Hydrodynamic analysis of a vertical axis tidal current turbine 

    E-Print Network [OSTI]

    Gretton, Gareth I.

    2009-01-01T23:59:59.000Z

    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 ...

  6. Tidal Energy Research

    SciTech Connect (OSTI)

    Stelzenmuller, Nickolas [Univ of Washington; Aliseda, Alberto [Univ of Washington; Palodichuk, Michael [Univ of Washington; Polagye, Brian [Univ of Washington; Thomson, James [Univ of Washington; Chime, Arshiya [Univ of Washington; Malte, Philip [Univ of washington

    2014-03-31T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    Gorlov, Alexander M. (Brookline, MA)

    1991-01-01T23:59:59.000Z

    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.

  8. Numerical study of the diapycnal flow through a tidal front with passive tracers

    E-Print Network [OSTI]

    Dong, Changming "Charles"

    . This qualitatively agrees with a recent field experiment using a dye tracer on Georges Bank. Additional experiments are performed to investigate the sensitivity of the tracer dispersion to the tidal phase and the location, the previous studies indicated Eulerian cross-front mean circu- lation maybe is in a multiple-cell structure

  9. Tidal power

    SciTech Connect (OSTI)

    Hammons, T.J. (Glasgow Univ., Scotland (United Kingdom))

    1993-03-01T23:59:59.000Z

    The paper reviews the physics of tidal power considering gravitational effects of moon and sun; semidiurnal, diurnal, and mixed tides; and major periodic components that affect the tidal range. Shelving, funneling, reflection, and resonance phenomena that have a significant effect on tidal range are also discussed. The paper then examines tidal energy resource for principal developments estimated from parametric modeling in Europe and worldwide. Basic parameters that govern the design of tidal power schemes in terms of mean tidal range and surface area of the enclosed basin are identified. While energy extracted is proportional to the tidal amplitude squared, requisite sluicing are is proportional to the square root of the tidal amplitude. Sites with large tidal amplitudes are therefore best suited for tidal power developments, whereas sites with low tidal amplitudes have sluicing that may be prohibitive. It is shown that 48% of the European tidal resource is in the United Kingdom, 42% in France and 8% in Ireland, other countries having negligible potential. Worldwide tidal resource is identified. Tidal barrage design and construction using caissons is examined, as are alternative operating modes (single-action generation, outflow generation, flood generation, two-way generation, twin basin generation, pumping, etc), development trends and possibilities, generation cost at the barrage boundary, sensitivity to discount rates, general economics, and markets. Environmental effects, and institutional constraints to the development of tidal barrage schemes are also discussed.

  10. 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

    2014-04-30T23:59:59.000Z

    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.

  11. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA)

    1997-01-01T23:59:59.000Z

    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.

  12. Automation of radiochemical analysis by applying flow

    E-Print Network [OSTI]

    Sánchez, David

    of detection systems, including scintillation counting, a-spectrometers, proportional counters, mass spectrometry and spectrophotometry. ª 2010 Published by Elsevier Ltd. Keywords: Flow-analysis technique; Flow

  13. 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

    ( , shape)/SIW, where Ptide is the effective tidal power that interacts with the topography, and /8 of a uniformly stratified fluid. The radiated power PIW and kinetic energy density of the boundary currents characterized by large kinetic energy densities form over critical topography ( = 1). However, we find

  14. 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

    ( , shape)/SIW, where Ptide is the effective tidal power that interacts with the topography, and /8 fluid. The radiated power PIW and kinetic energy density of the boundary currents are computed characterized by large kinetic energy densities form over critical topography ( = 1). However, we find

  15. Fluid Gravity Engineering Rocket motor flow analysis

    E-Print Network [OSTI]

    Anand, Mahesh

    Fluid Gravity Engineering Capability · Rocket motor flow analysis -Internal (performance) -External (plume / contamination) · Effect on landing site (surface alteration) -In-depth flow through porous young scientists/engineers Fluid Gravity Engineering Ltd #12;

  16. A Conceptual Restoration Plan and Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County, California

    E-Print Network [OSTI]

    Olson, Jessica J.

    2012-01-01T23:59:59.000Z

    Marsh. UC Berkeley LA 222 Hydrology Term Paper. Orr, M. , S.Restoration Plan and Tidal Hydrology Assessment forthree consists of a tidal hydrology analysis before and

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

    SciTech Connect (OSTI)

    Melaina, M.; Penev, M.

    2012-09-01T23:59:59.000Z

    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.

  18. Principles of Secure Information Flow Analysis Geoffrey Smith

    E-Print Network [OSTI]

    Smith, Geoffrey

    Principles of Secure Information Flow Analysis Geoffrey Smith School of Computing and Information to explain the #12;2 Geoffrey Smith principles underlying secure information flow analysis and to discuss

  19. Tidal Wetlands Regulations (Connecticut)

    Broader source: Energy.gov [DOE]

    Most activities occurring in or near tidal wetlands are regulated, and this section contains information on such activities and required permit applications for proposed activities. Applications...

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

    Open Energy Info (EERE)

    Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgwindex.php?titleClarenceStraitTidalEnergyProject,TenaxEnergyTropicalTidalTestCentre,&o...

  1. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect (OSTI)

    Not Available

    1980-11-01T23:59:59.000Z

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  2. A new variable in flow analysis

    E-Print Network [OSTI]

    Q. H. Zhang; L. Huo; W. N. Zhang

    2006-06-20T23:59:59.000Z

    We have used a simple spectrum distribution which was derived from a hydrodynamical equation\\cite{Csorgo} to fit the data of the STAR group. It is found that it can fit the $v_2$ of STAR group very well. We have found that $v_2$ is sensitive to both the effective temperature of particles and the expanding velocity. We have suggested a new variable ${\\bf z}$ to be used in the flow analysis. This new variable will measure the correlation of particles momentum components. We have also shown that one of the $x$ or $y$ direction in the reaction plane is the direction which has the largest variance.

  3. 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)

    2013-01-10T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Dan Lucas; Rich Kerswell

    2015-04-01T23:59:59.000Z

    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.

  5. Analysis of SPRIHTE LOPA flow excursion tests

    SciTech Connect (OSTI)

    Laurinat, J.E.

    1993-02-01T23:59:59.000Z

    The SPRIHTE FLOPA flow excursion tests, the results of which are presented here, have been modeled using FLOPA, the assembly thermal-hydraulics limits analysis code for the LOPA. FLOPA calculations show T{sub wall} = T{sub sat} is a reliable precursor to the onset of thermal excursion at prototypic flow rates during the ECS addition phase of the LOPA. A FLOPA model was created based on nominal dimensions for the SPRIHTE rig and an assumption that the rig`s cylinders were concentrically located. This model can determine when T{sub wall} = T{sub sat} if adjustments are made to account for differences between measured and calculated subchannel flow and heat transfer rates. To make these adjustments, a multiplier {beta} was applied to the wall saturation temperature criterion (T{sub wall} = {beta} T{sub sat}, in degrees C) to match measured and calculated powers at which the saturation temperature was first exceeded at the wall. Based on preliminary test results, a multiplier of 0.878 was recommended for use in calculating LOPA limits for the K-15.1 subcycle. This multiplier provides margins of 14% to 19% between the calculated wall saturation temperature limits and the measured powers at the onset of thermal excursion. The effective margins used in the final LOPA limits, which include dimensional and heat transfer model uncertainties and biases due to eccentricities, range from 38% to 41%. It is estimated that use of the wall saturation temperature criterion lowers the K-14.1 subcycle LOPA core power limit, which is based on a Stanton number of 0.0025, from 41% to 37% of the historical full power of 2400 MW. This report describes the SPRIHTE LOPA tests, describes and evaluates the FLOPA Model for the SPRIHTE tests, discusses selection of a limit criterion for the SPRIHTE tests, and evaluates the transition between high and low flow rate criteria. Calculated results and a sample of FLOPA input for the analysis of the SPRIHTE tests are provided.

  6. 12. Message Flow Analysis O.M. Nierstrasz

    E-Print Network [OSTI]

    Nierstrasz, Oscar

    12. Message Flow Analysis O.M. Nierstrasz ABSTRACT Message management systems with facilities of message flow from the procedure specifications. Message domains are partitioned into state spaces of message flow. 1. Overview Automatic processing and routing of electronic documents yields some interesting

  7. CFD analysis of laminar oscillating flows

    SciTech Connect (OSTI)

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

    2001-01-01T23:59:59.000Z

    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

    2010-01-01T23:59:59.000Z

    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. Flow Imaging Using MRI: Quantification and Analysis

    E-Print Network [OSTI]

    Jiraraksopakun, Yuttapong

    2010-07-14T23:59:59.000Z

    dynamics (CFD) and the conventional optimal flow imaging based on particle image velocimetry (PIV). The results demonstrated the improvement from the quantification using solely the conventional HARP method....

  10. 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.

    2010-06-23T23:59:59.000Z

    [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...

  11. 2008 NWFSC Tidal Freshwater Genetics Results

    SciTech Connect (OSTI)

    David Teel

    2009-05-01T23:59:59.000Z

    Genetic Analysis of Juvenile Chinook Salmon for inclusion in 'Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2008. Annual Report to Bonneville Power Administration, Contract DE-AC05-76RL01830.'

  12. 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

    2012-06-20T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    CONTINUOUS­TIME FINITE ELEMENT ANALYSIS OF MULTIPHASE FLOW IN GROUNDWATER HYDROLOGY Zhangxin Chen­water system in groundwater hydrology is given. The system is written in a fractional flow formulation, i for an air­water system in groundwater hydrology, ff = a; w [1], [11], [26]: @(OEae ff s ff ) @t +r \\Delta

  14. 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

    2012-01-01T23:59:59.000Z

    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. ...

  15. Mechanical analysis of a cross flow filter

    SciTech Connect (OSTI)

    Alvin, M.A.; Lippert, T.E.; Attaar, M.H.; McNerney, K.R.

    1992-12-01T23:59:59.000Z

    Material properties have also been generated at the Argonne National Laboratories which detail the fracture toughness, Weibull modulus, and critical flaw size for a specifically fabricated lot of P-100A alumina/mullite cross flow filters.(Singh, 1990) The critical flaw size within the P-100A matrix was estimated to be {approximately}500 {mu},m which includes both large interconnected pores, as well as potentially debonded areas along the mid-rib or gas channel seams. Critical flaws are generally considered as potential failure initiation sites within the ceramic matrix. In addition maximum filter element stress levels induced by the process system have been estimated at ANL through the use of finite element computer analyses. These efforts project that the highest stresses result within the flange region of the cross flow filter. As a result of these projections, efforts at Coors Ceramics were directed to improving the overall strength of the alumina/mullite material which is used for cross flow filter fabrication. The results of the efforts at Coors Ceramics provide a significant improvement in the hot strength of the P-100A alumina/mullite filter matrix. Westinghouse assessed the existing nondestructive evaluation (NDE) techniques in terms of identifying methods for detecting critical flaws within the cross flow filter body. To date viable, cost effective methods for detecting critical flaws within the P-100A alumina/mullite matrix, or along the mid-rib bonds or gas channel seams in the full-scale, porous ceramic cross flow filter element are not readily available. As an alternate approach, Westinghouse focused its attention on developing NDE techniques as inspection methods for evaluating the extent of bonding along the mid-rib bonds and gas channel seams which results during the various fabrication stages of the cross flow filter element.

  16. Mechanical analysis of a cross flow filter

    SciTech Connect (OSTI)

    Alvin, M.A.; Lippert, T.E.; Attaar, M.H.; McNerney, K.R.

    1992-01-01T23:59:59.000Z

    Material properties have also been generated at the Argonne National Laboratories which detail the fracture toughness, Weibull modulus, and critical flaw size for a specifically fabricated lot of P-100A alumina/mullite cross flow filters.(Singh, 1990) The critical flaw size within the P-100A matrix was estimated to be [approximately]500 [mu],m which includes both large interconnected pores, as well as potentially debonded areas along the mid-rib or gas channel seams. Critical flaws are generally considered as potential failure initiation sites within the ceramic matrix. In addition maximum filter element stress levels induced by the process system have been estimated at ANL through the use of finite element computer analyses. These efforts project that the highest stresses result within the flange region of the cross flow filter. As a result of these projections, efforts at Coors Ceramics were directed to improving the overall strength of the alumina/mullite material which is used for cross flow filter fabrication. The results of the efforts at Coors Ceramics provide a significant improvement in the hot strength of the P-100A alumina/mullite filter matrix. Westinghouse assessed the existing nondestructive evaluation (NDE) techniques in terms of identifying methods for detecting critical flaws within the cross flow filter body. To date viable, cost effective methods for detecting critical flaws within the P-100A alumina/mullite matrix, or along the mid-rib bonds or gas channel seams in the full-scale, porous ceramic cross flow filter element are not readily available. As an alternate approach, Westinghouse focused its attention on developing NDE techniques as inspection methods for evaluating the extent of bonding along the mid-rib bonds and gas channel seams which results during the various fabrication stages of the cross flow filter element.

  17. Analysis of oscillating flow cooled SMA actuator

    E-Print Network [OSTI]

    Pachalla Seshadri, Rajagopal

    2005-11-01T23:59:59.000Z

    for this heat transfer enhancement is that the oscillatory flow creates a very thin Stokes viscous boundary-layer and hence a large time-dependent transverse temperature gradient at the heated wall. Therefore heat transfer takes place at a large temperature...

  18. 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

    2011-09-01T23:59:59.000Z

    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.

  19. Overland Tidal Power Generation Using Modular Tidal Prism

    SciTech Connect (OSTI)

    Khangaonkar, Tarang; Yang, Zhaoqing; Geerlofs, Simon H.; Copping, Andrea

    2010-03-01T23:59:59.000Z

    Naturally occurring sites with sufficient kinetic energy suitable for tidal power generation with sustained currents > 1 to 2 m/s are relatively rare. Yet sites with greater than 3 to 4 m of tidal range are relatively common around the U.S. coastline. Tidal potential does exist along the shoreline but is mostly distributed, and requires an approach which allows trapping and collection to also be conducted in a distributed manner. In this paper we examine the feasibility of generating sustainable tidal power using multiple nearshore tidal energy collection units and present the Modular Tidal Prism (MTP) basin concept. The proposed approach utilizes available tidal potential by conversion into tidal kinetic energy through cyclic expansion and drainage from shallow modular manufactured overland tidal prisms. A preliminary design and configuration of the modular tidal prism basin including inlet channel configuration and basin dimensions was developed. The unique design was shown to sustain momentum in the penstocks during flooding as well as ebbing tidal cycles. The unstructured-grid finite volume coastal ocean model (FVCOM) was used to subject the proposed design to a number of sensitivity tests and to optimize the size, shape and configuration of MTP basin for peak power generation capacity. The results show that an artificial modular basin with a reasonable footprint (? 300 acres) has the potential to generate 10 to 20 kw average energy through the operation of a small turbine located near the basin outlet. The potential of generating a total of 500 kw to 1 MW of power through a 20 to 40 MTP basin tidal power farms distributed along the coastline of Puget Sound, Washington, is explored.

  20. Control Flow Analysis for Reverse Engineering of Sequence Diagrams

    E-Print Network [OSTI]

    Rountev, Atanas "Nasko"

    Control Flow Analysis for Reverse Engineering of Sequence Diagrams Atanas Rountev Olga Volgin and in software main- tenance. In static analysis for such reverse engineering, an open question is how to map an iteration. As pointed out in one popular book on modern software development [13], in this context

  1. 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

    2012-02-01T23:59:59.000Z

    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.

  2. Intracranial Pressure Variation Associated with Changes in End-Tidal CO2

    E-Print Network [OSTI]

    Intracranial Pressure Variation Associated with Changes in End-Tidal CO2 Sunghan Kim, James Mc that the partial pressure of arterial CO2 (PaCO2) can affect cerebral blood flow, cerebral blood volume, and therefore ICP. The end-tidal CO2 (ETCO2) is usually monitored by clinicians as a proxy for PaCO2. We show

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

    E-Print Network [OSTI]

    -mail: david@bpi.cam.ac.uk Abstract The transport of sediment over an intertidal mudflat by a cross-shore tidal lag and indicates that the cross-shore flows tend to accrete sediment on the intertidal mudflats and the amplitude of the tidal current. 1. Introduction Intertidal mudflats are extensive coastal regions

  4. Sandia National Laboratories: tidal energy resource assessment

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

    resource assessment Tidal Energy Resource Assessment in the East River Tidal Strait, New York On April 1, 2014, in Energy, News, News & Events, Partnership, Renewable Energy, Water...

  5. Weakly dispersive hydraulic flows in a contraction --Nonlinear stability analysis

    E-Print Network [OSTI]

    Ee, Bernard Kuowei

    Weakly dispersive hydraulic flows in a contraction -- Nonlinear stability analysis Bernard K. Ee hydraulic solutions of the forced Korteweg de-Vries equation is investigated here. For numerical convenience is destabilized by a hydraulic instability in which superexponential growth occurs prior to satura- tion

  6. university-logo Numerical stability analysis for thin film flow

    E-Print Network [OSTI]

    Marzuola, Jeremy

    university-logo Numerical stability analysis for thin film flow: toward rigorous verification Blake Barker Indiana University October 2, 2013 B. Rigorous verification #12;university-logo Viscous roll waves (Picture courtesy Neil Balmforth, UBC.) B. Rigorous verification #12;university-logo Viscous roll waves 0 2

  7. A numerical study of horizontal dispersion in a macro tidal basin

    E-Print Network [OSTI]

    Maine, University of

    boundary layer near the tidal mixing front on Georges Bank (Houghton and Ho 2001) and in Hudson River that significant horizon- tal dispersion and mixing can be induced in oscillatory flows (Aref 1984; Ottino 1989

  8. Microcomputer analysis of regenerative heat exchangers for oscillating flow

    SciTech Connect (OSTI)

    Hutchinson, R.A.; Lyke, S.E.

    1987-03-01T23:59:59.000Z

    Regenerative heat exchangers for use in oscillating flows such as those occurring in Stirling engines present considerable analytical problems to the thermal engineer. A simplified finite element analysis has been implemented in a spreadsheet, providing improved access to analytical assumptions and allowing parametric analysis of current heat transfer data. In addition, an irreversibility analysis has been implemented using the thermal and friction results in the spreadsheet. It is suited for evaluation and insights into loss tradeoffs inside operating regenerators, to suggest new regenerator design concepts, and to focus experimental work. 22 refs., 13 figs.

  9. 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 physical model of the flow of energy in a tidal wave. In a shallow­water­wave model of tide, the true flow­page comment on the DTI Energy Review, Salter [2005] suggests that this standard figure may well be an under

  10. 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 of the flow of energy in a tidal wave. In a shallow-water-wave model of tide, the true flow of en- ergy on the DTI Energy Review, Salter [2005] suggests that this standard figure may well be an under-estimate (see

  11. A comparison of measured and modeled tidal currents in the Gulf of Maine

    E-Print Network [OSTI]

    Cook, Michael S

    1990-01-01T23:59:59.000Z

    of Advisory Committee; Dr. David A. Brooks A modified version of the National Ocean Survey harmonic analysis computer program was used to extract the tidal signal from current meter records at five mooring stations (present stations) collected during four... summer periods in the Gulf of Maine. The results showed that the dominant tidal current constituent at all stations was the M2 constituent. The M2 tidal currents at each present station were vertically-averaged using a depth-weighting scheme...

  12. Stability Analysis of Large-Scale Incompressible Flow Calculations on Massively Parallel Computers 1 Stability Analysis of Large-

    E-Print Network [OSTI]

    Stability Analysis of Large-Scale Incompressible Flow Calculations on Massively Parallel Computers 1 Stability Analysis of Large- Scale Incompressible Flow Calculations on Massively Parallel disturbances aligned with the associated eigenvectors will grow. The Cayley transformation, cou- pled

  13. Energy flow lines as light paths a didactical analysis

    E-Print Network [OSTI]

    Horn, M E

    2006-01-01T23:59:59.000Z

    Analyses of interviews with secondary school students about their conceptions of light at the University of Potsdam indicate that numerous students have a deterministic view of light. With regard to these results the model of energy flow lines, which has been discussed recently in the didactical literature, is of special interest. Following this model, light is presumed to move along energy flow lines as trajectories. In an analysis of the model of energy flow lines four didactical dimensions (didactical content, internal structure, present-day relevance and future significance) are investigated. It can be shown that a discussion of this model in physics at school can increase the meta-conceptional knowledge of the students about the models of light. On the other hand, this can promote deterministic conceptions and the Bohm interpretation of quantum mechanics. But the question remains: Should the nature of light really be described as deterministic?

  14. AnalyzeHOLE: An Integrated Wellbore Flow Analysis Tool

    SciTech Connect (OSTI)

    Keith J. Halford

    2009-10-01T23:59:59.000Z

    Conventional interpretation of flow logs assumes that hydraulic conductivity is directly proportional to flow change with depth. However, well construction can significantly alter the expected relation between changes in fluid velocity and hydraulic conductivity. Strong hydraulic conductivity contrasts between lithologic intervals can be masked in continuously screened wells. Alternating intervals of screen and blank casing also can greatly complicate the relation between flow and hydraulic properties. More permeable units are not necessarily associated with rapid fluid-velocity increases. Thin, highly permeable units can be misinterpreted as thick and less permeable intervals or not identified at all. These conditions compromise standard flow-log interpretation because vertical flow fields are induced near the wellbore. AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction. A pumping well and adjacent aquifer system are simulated with an axisymmetric, radial geometry in a two-dimensional MODFLOW model. Hydraulic conductivities are distributed by depth and estimated with PEST by minimizing squared differences between simulated and measured flows and drawdowns. Hydraulic conductivity can vary within a lithology but variance is limited with regularization. Transmissivity of the simulated system also can be constrained to estimates from single-well, pumping tests. Water-quality changes in the pumping well are simulated with simple mixing models between zones of differing water quality. These zones are differentiated by backtracking thousands of particles from the well screens with MODPATH. An Excel spreadsheet is used to interface the various components of AnalyzeHOLE by (1) creating model input files, (2) executing MODFLOW, MODPATH, PEST, and supporting FORTRAN routines, and (3) importing and graphically displaying pertinent results.

  15. 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 multiphase power flow analysis method that provides exact solution to the operation of the µGrid under steady

  16. 228 POWER FLOW ANALYSIS parties, it is crucial to recognize the inherently subjective nature of OPF. Power flow

    E-Print Network [OSTI]

    Kammen, Daniel M.

    228 POWER FLOW ANALYSIS parties, it is crucial to recognize the inherently subjective nature of OPF. Power flow analysis by itself basically answers a question of physics. By contrast, OPF answers criteria. In short, "optim- ality" does not arise from a power system's intrinsic technical properties

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

    SciTech Connect (OSTI)

    A. Hassan; J. Chapman

    2008-11-01T23:59:59.000Z

    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

  18. Characterization of fracture networks for fluid flow analysis

    SciTech Connect (OSTI)

    Long, J.C.S.; Billaux, D.; Hestir, K.; Majer, E.L.; Peterson, J.; Karasaki, K.; Nihei, K.; Gentier, S.; Cox, L.

    1989-06-01T23:59:59.000Z

    The analysis of fluid flow through fractured rocks is difficult because the only way to assign hydraulic parameters to fractures is to perform hydraulic tests. However, the interpretation of such tests, or ''inversion'' of the data, requires at least that we know the geometric pattern formed by the fractures. Combining a statistical approach with geophysical data may be extremely helpful in defining the fracture geometry. Cross-hole geophysics, either seismic or radar, can provide tomograms which are pixel maps of the velocity or attenuation anomalies in the rock. These anomalies are often due to fracture zones. Therefore, tomograms can be used to identify fracture zones and provide information about the structure within the fracture zones. This structural information can be used as the basis for simulating the degree of fracturing within the zones. Well tests can then be used to further refine the model. Because the fracture network is only partially connected, the resulting geometry of the flow paths may have fractal properties. We are studying the behavior of well tests under such geometry. Through understanding of this behavior, it may be possible to use inverse techniques to refine the a priori assignment of fractures and their conductances such that we obtain the best fit to a series of well test results simultaneously. The methodology described here is under development and currently being applied to several field sites. 4 refs., 14 figs.

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

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    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. 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.

    2014-10-01T23:59:59.000Z

    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.

  1. Analysis of a Darcy flow model with a dynamic pressure saturation relation \\Lambda

    E-Print Network [OSTI]

    Hulshof, Joost

    equations modelling the flow. In the standard approach for two phase flows, such as oil­water or air­water mixtures, one combines the mass conservation equations and Darcy's law for the separate phasesAnalysis of a Darcy flow model with a dynamic pressure saturation relation \\Lambda Josephus Hulshof

  2. Accident Analysis and Prevention 36 (2004) 933946 Freeway safety as a function of traffic flow

    E-Print Network [OSTI]

    Detwiler, Russell

    2004-01-01T23:59:59.000Z

    Accident Analysis and Prevention 36 (2004) 933­946 Freeway safety as a function of traffic flow of strong relationships between traffic flow conditions and the likelihood of traffic accidents (crashes reserved. Keywords: Traffic safety; Accident rates; Traffic flow; Loop detectors; Speed; Traffic density

  3. 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)

    2001-01-01T23:59:59.000Z

    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.

  4. Tidally-induced thermonuclear Supernovae

    E-Print Network [OSTI]

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

    2008-11-13T23:59:59.000Z

    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.

  5. 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.

    the premature drop-out of magnetic-type tangential paddlewheel sensors, as well as several in-situ diagnostic measures for ascertaining whether or not a flow meter is experiencing turbulent conditions or if a flow sensor's output signal is suffering a degraded... per second for magnetic-type, and 0.5 to 2 feet per second for non-magnetic-type flow sensors deviated from the actual flow by 20% or more which makes the measurement of flow and thermal energy use in this regime highly suspect. Figure 4 also indicates...

  6. Visualization of Intricate Flow Structures for Vortex Breakdown Analysis Xavier Tricoche

    E-Print Network [OSTI]

    Utah, University of

    Visualization of Intricate Flow Structures for Vortex Breakdown Analysis Xavier Tricoche University, synthetic depictions that permit new insight into the structural properties of vortex breakdowns. CR And Modeling-- Simulation Output Analysis J.2 [Physical Sciences and Engineer- ing]: Engineering--. Keywords

  7. Quantifying Turbulence for Tidal Power Applications

    SciTech Connect (OSTI)

    Thomson, Jim; Richmond, Marshall C.; Polagye, Brian; Durgesh, Vibhav

    2010-08-01T23:59:59.000Z

    Using newly collected data from a tidal power site in Puget Sound, WA, metrics for turbulence quantification are assessed and discussed. The quality of raw ping Acoustic Doppler Current Profiler (ADCP) data for turbulence studies is evaluated against Acoustic Doppler Velocimeter (ADV) data at a point. Removal of Doppler noise from the raw ping data is shown to be a crucial step in turbulence quantification. Excluding periods of slack tide, the turbulent intensity estimates at a height of 4.6 m above the seabed are 8% and 11% from the ADCP and ADV, respectively. Estimates of the turbulent dissipation rate are more variable, from 10e-3 to 10e-1 W/m^3. An example analysis of coherent Turbulent Kinetic Energy (TKE) is presented.

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

    E-Print Network [OSTI]

    Justin Vines; Éanna É. Flanagan

    2014-10-09T23:59:59.000Z

    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.

  9. Sandia National Laboratories: tidal energy converters

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

    marine hydrokinetic (MHK) reference models (RMs) for wave energy converters and tidal, ocean, and river current energy converters. The RMP team includes a partnership between...

  10. Analysis of pressure drops under reversing flow conditions

    SciTech Connect (OSTI)

    Krazinski, J.L.; Holtz, R.E.; Uherka, K.L.; Lottes, P.A.

    1986-01-01T23:59:59.000Z

    This paper examines pressure-drop data from the Reversing Flow Test Facility (RFTF) at Argonne National Laboratory (ANL). The data comprise part of an initial series of measurements conducted with pressurized helium gas under reversing flow conditions. The characteristics of fluid pressure drops in compressible, reversing flows are discussed in the paper and compared with pressure-drop measurements for steady, incompressible flows. The methodology used to calculate instantaneous mass flows in the test section of the RFTF is summarized. The measured pressure drops are analyzed in terms of their frictional and inertial components. Pressure-drop data are presented for both tubes and wire mesh regenerators over a range of flow reversal frequencies. The results are discussed with reference to other experimental data and analytical models available in the literature. 10 refs., 6 figs., 2 tabs.

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

    Open Energy Info (EERE)

    Distributions Abstract A methodology for analyzing the internal flow characteristics of a fractured geothermal reservoir using tracer-determined residence time distribution curves...

  12. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolarTharaldson Ethanol LLCEnergyoThornwood,Tianfu PVOverseeingTidal

  13. Tidal Stream | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolarTharaldson Ethanol LLCEnergyoThornwood,TianfuTidal Sails AS

  14. Tidal | OpenEI Community

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin Hydropower Station Jump to: navigation, searchNewTidal Home

  15. POWER FLOW ANALYSIS OF ELECTROSTRICTIVE ACTUATORS DRIVEN BYSWITCHMODE AMPLIFIERS

    E-Print Network [OSTI]

    Lindner, Douglas K.

    is developed with includes a dynamic structural model of the actuator, a dynamic model of the power electronics. It is shown that an outer acoustic control loop can modify this mechanical admittance and optimize the power, the power flow between the electrical and mechanical systems is analyzed through simulation. The flow

  16. A COMPUTATIONAL ANALYSIS OF THE OPTIMAL POWER FLOW PROBLEM

    E-Print Network [OSTI]

    algorithms to handle this problem for the e - 1 security constrained optimal power flow problem. We also.3. The MATPOWER package 4 2.4. Graph theoretic notions 4 3. Security constrained optimal power flow 5 3, such as the breakdown of a generator or a fault in some transmission line. The importance of being able to supply power

  17. Three-dimensional Modeling of Tidal Hydrodynamics in the San Francisco Estuary

    E-Print Network [OSTI]

    Gross, Edward S.; MacWilliams, Michael L.; Kimmerer, Wim J.

    2009-01-01T23:59:59.000Z

    1993. Tidal residual intertidal mudflat (TRIM) model and itsthe Tidal Residual Intertidal Mudflat (TRIM) model (Casulli

  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.

    2013-04-28T23:59:59.000Z

    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. Load flow analysis: Base cases, data, diagrams, and results

    SciTech Connect (OSTI)

    Portante, E.C.; Kavicky, J.A.; VanKuiken, J.C.; Peerenboom, J.P.

    1997-10-01T23:59:59.000Z

    This report describes how an electric utility system is modeled by using load flow techniques to establish a validated power flow case suitable for simulating and evaluating alternative system scenarios. Details of the load flow model are supported by additional technical and descriptive information intended to correlate modeled electrical system parameters with the corresponding physical equipment that makes up the system. Pictures and technical specifications of system equipment from the utility, public, or vendor are provided to support this association for many system components. The report summarizes the load flow model construction, simulation, and validation and describes the general capabilities of an information query system designed to access load flow parameters and other electrical system information.

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

    Energy Savers [EERE]

    Tidal Streams in the United States Assessment of Energy Production Potential from Tidal Streams in the United States The project documented in this report created a national...

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

    SciTech Connect (OSTI)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J. [Georgia Institute of Technology, Atlanta, GA; Smith, Jeff [Electric Power Research Institute, Knoxville, TN; Dugan, Roger [Electric Power Research Institute, Knoxville, TN

    2013-01-01T23:59:59.000Z

    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.

  2. Relativistic theory of tidal Love numbers

    E-Print Network [OSTI]

    Taylor Binnington; Eric Poisson

    2009-09-16T23:59:59.000Z

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  3. 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.

    2014-10-29T23:59:59.000Z

    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.

  4. 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.

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

    E-Print Network [OSTI]

    Grunberg, Olivier, 1978-

    2004-01-01T23:59:59.000Z

    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 ...

  6. “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 ...

  7. Development of flow network analysis code for block type VHTR core by linear theory method

    SciTech Connect (OSTI)

    Lee, J. H.; Yoon, S. J. [Dept. of Nuclear Engr., Seoul National Univ., Daehak-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Park, J. W. [Dept. of Nuclear and Energy Engr, Dongguk Univ., Seokjang-Dong, Gyeongju, Gyeongsangbuk-Do, 780-714 (Korea, Republic of); Park, G. C. [Dept. of Nuclear Engr., Seoul National Univ., Daehak-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

    2012-07-01T23:59:59.000Z

    VHTR (Very High Temperature Reactor) is high-efficiency nuclear reactor which is capable of generating hydrogen with high temperature of coolant. PMR (Prismatic Modular Reactor) type reactor consists of hexagonal prismatic fuel blocks and reflector blocks. The flow paths in the prismatic VHTR core consist of coolant holes, bypass gaps and cross gaps. Complicated flow paths are formed in the core since the coolant holes and bypass gap are connected by the cross gap. Distributed coolant was mixed in the core through the cross gap so that the flow characteristics could not be modeled as a simple parallel pipe system. It requires lot of effort and takes very long time to analyze the core flow with CFD analysis. Hence, it is important to develop the code for VHTR core flow which can predict the core flow distribution fast and accurate. In this study, steady state flow network analysis code is developed using flow network algorithm. Developed flow network analysis code was named as FLASH code and it was validated with the experimental data and CFD simulation results. (authors)

  8. An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    and temperature distri- bution~ are given for several idealized models of the electroslag welding process) ) An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding Two physical models created and fluid flow phenom- ena in metals processing operations have been applied to electroslag weld- ing

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

    E-Print Network [OSTI]

    Alvarez Vera, Cesar

    2001-01-01T23:59:59.000Z

    -Darcy flow in the hydraulic fracture and its effects on pressure buildup analysis of hydraulically fractured gas reservoirs. A reservoir simulator was used to generate pressure drawdown and buildup data both with and without the effects of non-Darcy flow...

  10. innovati nNREL Uses Computing Power to Investigate Tidal Power

    E-Print Network [OSTI]

    innovati nNREL Uses Computing Power to Investigate Tidal Power Researchers at the National Renewable Energy Laboratory (NREL) have applied their knowledge of wind flow and turbulence to simulations water currents that carry a significant amount of kinetic energy. To capture this energy, several

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

    E-Print Network [OSTI]

    Blanco, Rafael Rodriguez

    2013-12-31T23:59:59.000Z

    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...

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

    Open Energy Info (EERE)

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

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

    Open Energy Info (EERE)

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

  14. An Equivalent Network for Load-Flow Analysis of Power Systems

    E-Print Network [OSTI]

    Johnson, Merion Luke

    1960-01-01T23:59:59.000Z

    AN EQUIVALENT NETWORK FOR LOAD-FLOW ANALYSIS OF POWER SYSTEMS A Thesis by Meri on L. Johnson Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partihl fulfillment of the requirements for the degree...

  15. Analysis of Flow Phenomena in Virtual Environments Benefits, Challenges, and Solutions

    E-Print Network [OSTI]

    Kuhlen, Torsten

    ) ­ is nowadays an indispensable and essential tool for the development of, e.g., airplanes, cars, combustion engines, turbines etc. Even in medicine, CFD is going to play an important role in the analysis of flow

  16. Atmospheric heat redistribution and collapse on tidally locked rocky planets

    E-Print Network [OSTI]

    Wordsworth, Robin

    2014-01-01T23:59:59.000Z

    Atmospheric collapse is likely to be of fundamental importance to tidally locked rocky exoplanets but remains understudied. Here, general results on the heat transport and stability of tidally locked terrestrial-type atmospheres are reported. First, the problem is modeled with an idealized 3D general circulation model (GCM) with gray gas radiative transfer. It is shown that over a wide range of parameters the atmospheric boundary layer, rather than the large-scale circulation, is the key to understanding the planetary energy balance. Through a scaling analysis of the interhemispheric energy transfer, theoretical expressions for the day-night temperature difference and surface wind speed are created that reproduce the GCM results without tuning. Next, the GCM is used with correlated-k radiative transfer to study heat transport for two real gases (CO2 and CO). For CO2, empirical formulae for the collapse pressure as a function of planetary mass and stellar flux are produced, and critical pressures for atmospher...

  17. Tidal Heating of Extra-Solar Planets

    E-Print Network [OSTI]

    Brian Jackson; Richard Greenberg; Rory Barnes

    2008-02-29T23:59:59.000Z

    Extra-solar planets close to their host stars have likely undergone significant tidal evolution since the time of their formation. Tides probably dominated their orbital evolution once the dust and gas had cleared away, and as the orbits evolved there was substantial tidal heating within the planets. The tidal heating history of each planet may have contributed significantly to the thermal budget that governed the planet's physical properties, including its radius, which in many cases may be measured by observing transit events. Typically, tidal heating increases as a planet moves inward toward its star and then decreases as its orbit circularizes. Here we compute the plausible heating histories for several planets with measured radii, using the same tidal parameters for the star and planet that had been shown to reconcile the eccentricity distribution of close-in planets with other extra-solar planets. Several planets are discussed, including for example HD 209458 b, which may have undergone substantial tidal heating during the past billion years, perhaps enough to explain its large measured radius. Our models also show that GJ 876 d may have experienced tremendous heating and is probably not a solid, rocky planet. Theoretical models should include the role of tidal heating, which is large, but time-varying.

  18. Tidal deformations of a spinning compact object

    E-Print Network [OSTI]

    Paolo Pani; Leonardo Gualtieri; Andrea Maselli; Valeria Ferrari

    2015-03-25T23:59:59.000Z

    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.

  19. Carbon flow and ecosystem dynamics in the Mississippi River plume described by inverse analysis

    E-Print Network [OSTI]

    Breed, Greg Allen

    2002-01-01T23:59:59.000Z

    for the degree of MASTER OF SCIENCE December 2002 Major Subject: Oceanography CARBON FLOW AND ECOSYSTEM DYNAMICS IN THE MISSISSIPPI RIVER PLUME DESCRIBED BY INVERSE ANALYSIS A Thesis by GREG ALLEN BREED Submitted to Texas A&M University in partial... of Department) December 2002 Major Sublect: Oceanography ABSTRACT Carbon Flow and Ecosystem Dynamics in the Mississippi River Plume Described by Inverse Analysis. (December 2002) Greg Allen Breed, B. S. , University of Minnesota Chair of Advisory...

  20. A finite element viscous flow analysis in a radial turbine scroll

    E-Print Network [OSTI]

    Hill, Donald Lee

    1987-01-01T23:59:59.000Z

    A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis DONALD LEE HILL JR. Submitted to the Graduate College. of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1987 Major Subject: Mechanical Engineering A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis by DONALD LEE HILL JR. Approved as to style snd content by: Dr. Erian A. Baskharone (Chairman of Conunittee) Dr. Alan B azzolo...

  1. Development of magnetic separation methods of analysis: magnetic field flow fractionation

    E-Print Network [OSTI]

    Garcia-Ramirez, Jaime

    1980-01-01T23:59:59.000Z

    DEVELOPMENT OF MAGNETIC SEPARATION METHODS OF ANALYSIS: MAGNETIC FIELD FLOW FRACTIONATION A Thesis by JAIME GARCIA-RAMIREZ Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1980 Major Subject: Chemistry DEVELOPMENT OF MAGNETIC SEPARATION METHODS OF ANALYSIS: MAGNETIC FIELD FLOW FRACTIONATION A Thesis by JAIME GARCIA-RAMIREZ Approved as to style and content by: (Chairman of Committee) 1...

  2. 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.

  3. A Conceptual Restoration Plan and Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County, California

    E-Print Network [OSTI]

    Olson, Jessica J.

    2012-01-01T23:59:59.000Z

    tidal wetland below MHLW Table 4.19. Performance IndicatorsPerformance Indicator All Tidal wetlands Tidal wetlands All

  4. Analysis of Transient Processes in a Radiophysical Flow System

    E-Print Network [OSTI]

    E. N. Egorov; A. A. Koronovskii; A. E. Hramov

    2006-01-31T23:59:59.000Z

    Transient processes in a third-order radiophysical flow system are studied and a map of the transient process duration versus initial conditions is constructed and analyzed. The results are compared to the arrangement of submanifolds of the stable and unstable cycles in the Poincare section of the system studied.

  5. Transaction Based Power Flow Analysis For Transmission Utilization Allocation

    E-Print Network [OSTI]

    transactions as well as the effect of reactive power on transmission losses and active power flows. Two the electric power industry moves into an era of supply competition and consumer choice, the power system electricity market at the ex ante phase; (ii) MW generations are decided by bilateral contracts and other

  6. Sensitivity Analysis and Stochastic Simulations of Non-equilibrium Plasma Flow

    SciTech Connect (OSTI)

    Lin, Guang; Karniadakis, George E.

    2009-11-05T23:59:59.000Z

    We study parametric uncertainties involved in plasma flows and apply stochastic sensitivity analysis to rank the importance of all inputs to guide large-scale stochastic simulations. Specifically, we employ different gradient-based sensitivity methods, namely Morris, multi-element probabilistic collocation method (ME-PCM) on sparse grids, Quasi-Monte Carlo, and Monte Carlo methods. These approaches go beyond the standard ``One-At-a-Time" sensitivity analysis and provide a measure of the nonlinear interaction effects for the uncertain inputs. The objective is to perform systematic stochastic simulations of plasma flows treating only as {\\em stochastic processes} the inputs with the highest sensitivity index, hence reducing substantially the computational cost. Two plasma flow examples are presented to demonstrate the capability and efficiency of the stochastic sensitivity analysis. The first one is a two-fluid model in a shock tube while the second one is a one-fluid/two-temperature model in flow past a cylinder.

  7. 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...

  8. 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

    2015-09-01T23:59:59.000Z

    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

  9. The Development of Loss of Flow Analysis Method for OPR1000 Using RETRAN

    SciTech Connect (OSTI)

    Dong Hyuk Lee; Yo-Han Kim; Chang-Kyung Sung [Korea Electric Power Research Institute, 103-16 Munji-Dong, Yuseong-Gu, Daejeon, 305-380 (Korea, Republic of)

    2006-07-01T23:59:59.000Z

    A new loss of flow transient analysis method for OPR1000 (Optimized Power Reactor 1000, previously called KSNP: Korean Standard Nuclear Power Plant) based on RETRAN code were developed. The reference plant for the analysis is Ulchin Unit 3 and the transient analyzed is 4 pump coast-down. The current analysis for loss of RCS flow transient of OPR1000 uses COAST and CESEC codes. The new method uses RETRAN code to replace COAST and CESEC codes. Since the ability of RETRAN to replace CESEC has been studied in other non-LOCA transients, this paper will focus on COAST code and RCP coast-down flow rates. The results from simplified RETRAN nodalization corresponding to COAST show good agreement with RCS flow results from COAST code. The results are also compared with RETRAN base-deck for safety analysis which is more complex and show similar trends. Therefore, previous analysis method for loss of flow of OPR1000 using COAST code can be replaced with the new analysis method based on RETRAN. (authors)

  10. Viscoelastic Models of Tidally Heated Exomoons

    E-Print Network [OSTI]

    Dobos, Vera

    2015-01-01T23:59:59.000Z

    Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life is intensely studied on Solar System moons such as Europa or Enceladus, where the surface ice layer covers tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. For studying the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models, because it takes into account the temperature dependency of the tidal heat flux, and the melting of the inner material. With the use of this model we introduced the circumplanetary Tidal Temperate Zone (TTZ), that strongly depends on the orbital period of the moon, and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ usi...

  11. 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

  12. A Flow-Channel Analysis for the Mars Hopper

    SciTech Connect (OSTI)

    W. Spencer Cooley

    2013-02-01T23:59:59.000Z

    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.

  13. Contraction and distension by tidal stress and its role as the cause of the Hubble redshift

    E-Print Network [OSTI]

    V Guruprasad

    2000-05-22T23:59:59.000Z

    I show that a cumulative contraction or expansion must result from repetitive tidal action in a curved stress field, depending on the direction of the curvature. The resulting expansion of solid materials onboard deep space probes and the corresponding contraction on earth would be of the right magnitude to account for all aspects of the Pioneer anomaly, leading to the two component model previously proposed. Importantly, I show via signal path analysis that the anomaly mathematically implies planetary Hubble flow, and that it is predicted by the standard model equations when the cosmological constant is also taken into account at this range. Also shown is that the variations of the anomaly do not permit a different explanation. The prediction of the Hubble flow occurring as a result in the view of the shrinking observer is now fully explained from both quantum and Doppler perspectives, fundamentally challenging the cosmological ideas of the past century. Lastly, I discuss how the contraction reconciles the geological evidence of a past expansion of the earth.

  14. Tidal Evolution of Rubble Piles

    E-Print Network [OSTI]

    Peter Goldreich; Re'em Sari

    2007-12-04T23:59:59.000Z

    Many small bodies in the solar system are believed to be rubble piles, a collection of smaller elements separated by voids. We propose a model for the structure of a self-gravitating rubble pile. Static friction prevents its elements from sliding relative to each other. Stresses are concentrated around points of contact between individual elements. The effective dimensionless rigidity, $\\tilde\\mu_{rubble}$, is related to that of a monolithic body of similar composition and size, $\\tilde\\mu$ by $\\tilde \\mu_{rubble} \\sim \\tilde \\mu^{1/2} \\epsilon_Y^{-1/2}$, where $\\epsilon_Y \\sim 10^{-2}$ is the yield strain. This represents a reduction in effective rigidity below the maximum radius, $R_{max}\\sim [\\mu\\epsilon_Y/(G\\rho^2)]^{1/2}\\sim 10^3\\km$, at which a rubble pile can exist. Densities derived for binary near-Earth asteroids imply that they are rubble piles. As a consequence, their tidal evolution proceeds $10^3$ to $10^4$ times faster than it would if they were monoliths. This accounts for both the sizes of their semimajor axes and their small orbital eccentricities. We show that our model for the rigidity of rubble piles is compatible with laboratory experiment in sand.

  15. Fitting orbits to tidal streams

    E-Print Network [OSTI]

    James Binney

    2008-02-11T23:59:59.000Z

    Recent years have seen the discovery of many tidal streams through the Galaxy. Relatively straightforward observations of a stream allow one to deduce three phase-space coordinates of an orbit. An algorithm is presented that reconstructs the missing phase-space coordinates from these data. The reconstruction starts from assumed values of the Galactic potential and a distance to one point on the orbit, but with noise-free data the condition that energy be conserved on the orbit enables one to reject incorrect assumptions. The performance of the algorithm is investigated when errors are added to the input data that are comparable to those in published data for the streams of Pal 5. It is found that the algorithm returns distances and proper motions that are accurate to of order one percent, and enables one to reject quite reasonable but incorrect trial potentials. In practical applications it will be important to minimize errors in the input data, and there is considerable scope for doing this.

  16. Pool spacing, channel morphology, and the restoration of tidal forested wetlands of the Columbia River, U.S.A.

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Montgomery, David R.

    2008-10-09T23:59:59.000Z

    Tidal forested wetlands have sustained substantial areal losses, and restoration practitioners lack a description of many ecosystem structures associated with these late-successional systems in which surface water is a significant controlling factor on the flora and fauna. The roles of large woody debris in terrestrial and riverine ecosystems have been well described compared to functions in tidal areas. This study documents the role of large wood in forcing channel morphology in Picea-sitchensis (Sitka spruce) dominated freshwater tidal wetlands in the floodplain of the Columbia River, U.S.A. near the Pacific coast. The average pool spacing documented in channel surveys of three freshwater tidal forested wetlands near Grays Bay were 2.2 ± 1.3, 2.3 ± 1.2, and 2.5 ± 1.5. There were significantly greater numbers of pools on tidal forested wetland channels than on a nearby restoration site. On the basis of pool spacing and the observed sequences of log jams and pools, the tidal forested wetland channels were classified consistent with a forced step-pool class. Tidal systems, with bidirectional flow, have not previously been classified in this way. The classification provides a useful basis for restoration project design and planning in historically forested tidal freshwater areas, particularly in regard to the use of large wood in restoration actions and the development of pool habitats for aquatic species. Significant modifications by beaver on these sites warrant further investigation to explore the interactions between these animals and restoration actions affecting hydraulics and channel structure in tidal areas.

  17. Materials Flows through Industry (MFI) Tool Â… AMO Analysis Review

    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 onYouTube YouTube Note: Since the.pdfBreaking ofOil & GasTechnical Publications »of EnergyMaterials Flows through

  18. 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 [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-01-29T23:59:59.000Z

    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.

  19. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Jump to:(RES-AEI) |Rock GeothermalExploration

  20. 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

  1. Combining remote sensing data and an inundation model to map tidal mudflat regions and improve flood predictions: A proof of concept

    E-Print Network [OSTI]

    Ezer,Tal

    Combining remote sensing data and an inundation model to map tidal mudflat regions and improve mudflats. The remote sensing-based analysis provides for the first time a way to evaluate the flood., and H. Liu (2009), Combining remote sensing data and an inundation model to map tidal mudflat regions

  2. Symmetry group analysis of an ideal plastic flow

    E-Print Network [OSTI]

    Vincent Lamothe

    2011-02-11T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Carolyn Lambert; Vardarajan Suneeta

    2012-09-01T23:59:59.000Z

    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.

  4. An analysis of the induced flow downstream between oscillating wings in a wind tunnel

    E-Print Network [OSTI]

    Morgan, Barry Erwin

    1970-01-01T23:59:59.000Z

    AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TIMBAL A Thesis by BARRY ERWIN MORGAN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1970 Major Subject; Aerospace Engineering AN ANALYSIS OF THE INDUCED FLOW DOWNSTREAM BETWEEN OSCILLATING WINGS IN A WIND TUNNEL A Thesis by BARRY ERWIN MORGAN Approved as to style and content by: rman of Committee) (Hea of Depart ent...

  5. Newton-Krylov Methods in Power Flow and Contingency Analysis

    E-Print Network [OSTI]

    Vuik, Kees

    for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems are calculated given the generation and consumption. In contingency analysis, equipment outages are simulated

  6. Power flow analysis for DC voltage droop controlled DC microgrids

    E-Print Network [OSTI]

    Chaudhary, Sanjay

    loss, such as photovoltaic panels, batteries, fuel cells, LEDs, and electronic loads, DC microgrids sharing and secondary voltage regulation can now be analytically studied, and specialized optimization of the DC microgrid, in term of systematic analysis, protection coordination design, network optimization

  7. 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

  8. 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

    2013-06-13T23:59:59.000Z

    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.

  9. Non-perturbative analysis of space charge limited electron flow in critical regimes

    SciTech Connect (OSTI)

    Rokhlenko, A.; Lebowitz, J. L. [Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2014-08-07T23:59:59.000Z

    The combined Eulerian-Lagrangian formalism, developed in our previous work for studying the turn on regime of a one-dimensional diode, is extended for wider versatility and better precision in the study of the time dependent space charge limited electron flow with fixed injected current. An analytical analysis is supplemented with an approximate numerical scheme which appears to be sufficiently accurate to calculate the flow evolution until the process approaches stabilization or becomes unstable. This can be compared with properties of stationary flows and showed to be in a good agreement with them. When the stabilization is impossible, the ratio of anode to cathode currents is decreasing and thus the space charge is accumulated in the diode. We discuss the limitations of our approach and give some qualitative estimates for the flow parameters when stabilization is impossible.

  10. Stochastic Simulations and Sensitivity Analysis of Plasma Flow

    SciTech Connect (OSTI)

    Lin, Guang; Karniadakis, George E.

    2008-08-01T23:59:59.000Z

    For complex physical systems with large number of random inputs, it will be very expensive to perform stochastic simulations for all of the random inputs. Stochastic sensitivity analysis is introduced in this paper to rank the significance of random inputs, provide information on which random input has more influence on the system outputs and the coupling or interaction effect among different random inputs. There are two types of numerical methods in stochastic sensitivity analysis: local and global methods. The local approach, which relies on a partial derivative of output with respect to parameters, is used to measure the sensitivity around a local operating point. When the system has strong nonlinearities and parameters fluctuate within a wide range from their nominal values, the local sensitivity does not provide full information to the system operators. On the other side, the global approach examines the sensitivity from the entire range of the parameter variations. The global screening methods, based on One-At-a-Time (OAT) perturbation of parameters, rank the significant parameters and identify their interaction among a large number of parameters. Several screening methods have been proposed in literature, i.e., the Morris method, Cotter's method, factorial experimentation, and iterated fractional factorial design. In this paper, the Morris method, Monte Carlo sampling method, Quasi-Monte Carlo method and collocation method based on sparse grids are studied. Additionally, two MHD examples are presented to demonstrate the capability and efficiency of the stochastic sensitivity analysis, which can be used as a pre-screening technique for reducing the dimensionality and hence the cost in stochastic simulations.

  11. 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)

    1996-03-01T23:59:59.000Z

    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.

  12. Toward compressed DMD: spectral analysis of fluid flows using sub-Nyquist-rate PIV data

    E-Print Network [OSTI]

    Tu, Jonathan H; Kutz, J Nathan; Shang, Jessica K

    2014-01-01T23:59:59.000Z

    Dynamic mode decomposition (DMD) is a powerful and increasingly popular tool for performing spectral analysis of fluid flows. However, it requires data that satisfy the Nyquist-Shannon sampling criterion. In many fluid flow experiments, such data are impossible to capture. We propose a new approach that combines ideas from DMD and compressed sensing. Given a vector-valued signal, we take measurements randomly in time (at a sub-Nyquist rate) and project the data onto a low-dimensional subspace. We then use compressed sensing to identify the dominant frequencies in the signal and their corresponding modes. We demonstrate this method using two examples, analyzing both an artificially constructed test dataset and particle image velocimetry data collected from the flow past a cylinder. In each case, our method correctly identifies the characteristic frequencies and oscillatory modes dominating the signal, proving the proposed method to be a capable tool for spectral analysis using sub-Nyquist-rate sampling.

  13. Large Eddy Simulation Analysis of Flow Field Inside a High-g Combustor

    E-Print Network [OSTI]

    Raman, Venkat

    Large Eddy Simulation Analysis of Flow Field Inside a High-g Combustor C. Heye , C. Lietz , J-compact combustors (UCC) are a technology for reducing the size of combustors. In these combustors the fuel and air results exhibit significant entrainment of fuel into recirculation zones inside the combustor, however

  14. 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

  15. Operation-Based Signal-Flow AC Analysis of Switching DCDC Converters in CCM and DCM

    E-Print Network [OSTI]

    Rincon-Mora, Gabriel A.

    Operation-Based Signal-Flow AC Analysis of Switching DC­DC Converters in CCM and DCM Dongwon Kwon (CCM and DCM) and insightful enough to derive directly from the waveforms of the circuit, not from- and discontinuous-conduction modes (CCM and DCM). To this end, for review, Sections II and III of the paper overview

  16. A perturbation analysis of the unstable plastic flow pattern evolution in an aluminum alloy

    E-Print Network [OSTI]

    Tong, Wei

    A perturbation analysis of the unstable plastic flow pattern evolution in an aluminum alloy Seung Abstract In the tensile loading of sheet metals made from some polycrystalline aluminum alloys, a single in the uniaxial tension of polycrystalline aluminum alloys with periodic stress relaxations depends

  17. 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

  18. Flow analysis and nozzle-shape optimization for the cold-gas dynamic-spray process

    E-Print Network [OSTI]

    Grujicic, Mica

    Flow analysis and nozzle-shape optimization for the cold-gas dynamic-spray process M Grujicic1*, W, maximizes the acceleration of the particles. Furthermore, it is found that if the cold-spray nozzle, a significant increase in the average velocity of the particles at the nozzle exit can be obtained

  19. Two-phase refrigerant flow instability analysis and active control in transient electronics cooling systems

    E-Print Network [OSTI]

    Peles, Yoav

    Two-phase refrigerant flow instability analysis and active control in transient electronics cooling Pressure-drop oscillation Refrigeration system Two-phase cooling Active control Transient heat load a b s t r a c t Two-loop refrigeration systems are being explored for two-phase cooling of ultra high power

  20. 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

  1. 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

  2. Randomized flow model and centrality measure for electrical power transmission network analysis

    E-Print Network [OSTI]

    Boyer, Edmond

    the vulnerability of electric power infrastructure systems [2, 3]. The focus of these types of studies is typically1 Randomized flow model and centrality measure for electrical power transmission network analysis. Centrality measures can then be coherently defined. An example of application to an electrical power

  3. 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 With larger portion of growing electricity demand which is being fed through distributed generation (DG power system. Being able to operate in both grid-connected and islanded mode, a microgrid manages

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

    SciTech Connect (OSTI)

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

    2013-07-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Craig W. Collar

    2012-11-16T23:59:59.000Z

    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.

  6. Analysis of patuxent estuarine currents in the vicinity of the Chalk Point Steam Electric Station. Final report

    SciTech Connect (OSTI)

    Polgar, T.T.; Ross, R.N.; Lacey, G.K.

    1980-03-01T23:59:59.000Z

    The tidal and nontidal flows in the Patuxent River, between Trueman Point and Benedict Bridge, are described, using time series analysis methods on continuously recording current meter data. The measurements were made in July and August 1978; the entire study area falls within the mesohaline region of the estuary. The results of the analyses indicate that currents in the study area are driven predominantly by semi-diurnal tidal forcing and by wind patterns. Freshwater input into the estuary accounts for the maintenance of vertical density gradients and shears, but it plays a relatively minor role in the estuarine transport processes.

  7. Ring diagram analysis of near-surface flows in the Sun

    E-Print Network [OSTI]

    Sarbani Basu; H. M. Antia; S. C. Tripathy

    1998-09-24T23:59:59.000Z

    Ring diagram analysis of solar oscillation power spectra obtained from MDI data is carried out to study the velocity fields in the outer part of the solar convection zone. The three dimensional power spectra are fitted to a model which has a Lorentzian profile in frequency and which includes the advection of the wave front by horizontal flows, to obtain the two components of the sub-surface flows as a function of the horizontal wave number and radial order of the oscillation modes. This information is then inverted using OLA and RLS methods to infer the variation in horizontal flow velocity with depth. The average rotation velocity at different latitudes obtained by this technique agrees reasonably with helioseismic estimates made using frequency splitting data. The shear layer just below the solar surface appears to consist of two parts with the outer part up to a depth of 4 Mm, where the velocity gradient does not show any reversal up to a latitude of 60 degrees. In the deeper part the velocity gradient shows reversal in sign around a latitude of 55 degrees. The zonal flow velocities inferred in the outermost layers appears to be similar to those obtained by other measurements. A meridional flow from equator polewards is found. It has a maximum amplitude of about 30 m/s near the surface and the amplitude is nearly constant in the outer shear layer.

  8. Modal Wavelets Analysis to Gas-Liquid Two Phase Flow PIV Images

    SciTech Connect (OSTI)

    Masahiro Takei [Nihon University, 1866 Kameino, Fujisawa-Shi, Kanagawa 252-8510 (Japan); Hassan, Yassin A. [Texas A and M University, College Station, Texas 77843 (United States); Ortiz-Villafuerte, J. [National Institute for Nuclear Research, Carretera Mexico Toluca Km.36.5, 52045 Municipio de Ocoyoacac, Salazar. Edo. de Mexico, C.P.52046 Mexico (Mexico); Tomomasa Uemura [Kansai University, Suita-shi, Osaka 564 (Japan)

    2006-07-01T23:59:59.000Z

    A modal wavelet transform, which overcomes the intrinsic data number limitation of power of two to conventional wavelet transform, has been applied to analysis of pseudo and real bubbly flow PIV images. The modal wavelet transform is compared with the discrete wavelet transform in order to select the best base function among Neumann, Dirichlet and Green function types base functions. Consequently, it is verified that Neumann type base function is the best because the correlation of Neumann type base function is the highest. From the result of wavelet analysis of the real bubbly flow PIV image, as the relative velocity is higher, the dominant eddy scale becomes smaller. The extraction modal wavelet level depends on the base function. (authors)

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

    E-Print Network [OSTI]

    Hoffman, Joe Douglas

    1959-01-01T23:59:59.000Z

    ~ 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...

  10. Local analysis of three-dimensional air cooled condenser using a two-phase flow diagram

    SciTech Connect (OSTI)

    Parise, J.A.R.; Cartwright

    1983-07-01T23:59:59.000Z

    This paper is concerned with the development and application of an analytical method for the performance prediction of air cooled condensers. A local analysis is employed in which the condenser is considered as a matrix of small basic heat transfer modules. For each element, local film coefficients for both the air and the condensing fluid are determined according to the existing local conditions, including the two-phase flow regime. The paper considers an application of the method to heat pump condensing.

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

    SciTech Connect (OSTI)

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

    2004-03-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Larsen, Benjamin A

    2014-05-01T23:59:59.000Z

    STATISTICAL ANALYSIS OF MICROGRAVITY TWO-PHASE SLUG FLOW VIA THE DRIFT FLUX MODEL A Thesis by BENJAMIN ANDREW LARSEN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment... made their data available to me and willingly took the time to converse about their work. Finally I would like to thank my parents Donald and Christine Larsen for their love and support in completing my graduate work. v NOMENCLATURE Symbol...

  13. Turbulence and internal waves in tidal flow over topography

    E-Print Network [OSTI]

    Gayen, Bishakhdatta

    2012-01-01T23:59:59.000Z

    structures in oscillatory boundary layers. J. Fluid. Mech.structures in oscillatory boundary layers. J. Fluid Mech.zero time-mean oscillatory boundary layer based on the value

  14. Assessment of HTGR Helium Compressor Analysis Tool Based on Newton-Raphson Numerical Application to Through-flow Analysis

    SciTech Connect (OSTI)

    Ji Hwan Kim; Hyeun Min Kim; Hee Cheon NO [Korea Advanced Institute of Science and Technology, 335 Gwahangno - 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2006-07-01T23:59:59.000Z

    This study describes the development of a computer program for analyzing the off-design performance of axial flow helium compressors, which is one of the major concerns for the power conversion system of a high temperature gas-cooled reactor (HTGR). The compressor performance has been predicted by the aerodynamic analysis of meridional flow with allowances for losses. The governing equations have been derived from Euler turbomachine equation and the streamline curvature method, and then they have been merged into linearized equations based on the Newton-Raphson numerical method. The effect of viscosity is considered by empirical correlations to introduce entropy rises caused by primary loss sources. Use of the method has been illustrated by applying it to a 20-stage helium compressor of the GTHTR300 plant. As a result, the flow throughout the stages of the compressor has been predicted and the compressor characteristics have been also investigated according to the design specification. The program results show much better stability and good convergence with respect to other through-flow methods, and good agreement with the compressor performance map provided by JAEA. (authors)

  15. Tidally-induced warps in protostellar discs

    E-Print Network [OSTI]

    C. Terquem; J. Papaloizou; R. Nelson

    1998-10-01T23:59:59.000Z

    We review results on the dynamics of warped gaseous discs. We consider tidal perturbation of a Keplerian disc by a companion star orbiting in a plane inclined to the disc. The perturbation induces the precession of the disc, and thus of any jet it could drive. In some conditions the precession rate is uniform, and as a result the disc settles into a warp mode. The tidal torque also leads to the truncation of the disc, to the evolution of the inclination angle (not necessarily towards alignment of the disc and orbital planes) and to a transport of angular momentum in the disc. We note that the spectral energy distribution of such a warped disc is different from that of a flat disc. We conclude by listing observational effects of warps in protostellar discs.

  16. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect (OSTI)

    Henning, Wade G.; Hurford, Terry, E-mail: wade.g.henning@nasa.gov [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

    2014-07-01T23:59:59.000Z

    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.

  17. Tidal interactions in multi-planet systems

    E-Print Network [OSTI]

    Papaloizou, J C B

    2011-01-01T23:59:59.000Z

    We study systems of close orbiting planets evolving under the influence of tidal circularization. It is supposed that a commensurability forms through the action of disk induced migration and orbital circularization. After the system enters an inner cavity or the disk disperses the evolution continues under the influence of tides due to the central star which induce orbital circularization. We derive approximate analytic models that describe the evolution away from a general first order resonance that results from tidal circularization in a two planet system and which can be shown to be a direct consequence of the conservation of energy and angular momentum. We consider the situation when the system is initially very close to resonance and also when the system is between resonances. We also perform numerical simulations which confirm these models and then apply them to two and four planet systems chosen to have parameters related to the GJ581 and HD10180 systems. We also estimate the tidal dissipation rates t...

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

    SciTech Connect (OSTI)

    Wright, Bruce Albert [Aleutian Pribilof Islands Association] [Aleutian Pribilof Islands Association

    2014-05-07T23:59:59.000Z

    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.

  19. Tidal Energy System for On-Shore Power Generation

    SciTech Connect (OSTI)

    Bruce, Allan J

    2012-06-26T23:59:59.000Z

    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

  20. EXPERIMENTAL AND NUMERICAL ANALYSIS OF THE FLOW INSIDE A CONFIGURATION INCLUDING AN AXIAL PUMP AND A TUBULAR

    E-Print Network [OSTI]

    Boyer, Edmond

    EXPERIMENTAL AND NUMERICAL ANALYSIS OF THE FLOW INSIDE A CONFIGURATION INCLUDING AN AXIAL PUMP-30723) In centrifugal and axial pumps, the flow is characterized by a turbulent and complex behavior and also of a configuration that includes an axial pump and a bundle of tubes that mimics the cool source of a heat exchanger

  1. Time evolution of electron flow in a model diode: Non-perturbative analysis

    SciTech Connect (OSTI)

    Rokhlenko, A.; Lebowitz, J. L. [Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2013-12-21T23:59:59.000Z

    Using a combination of Eulerian and Lagrangian variables we study the time evolution of the electron flow from a no-current state to a final state with the stationary current in a planar one-dimensional diode. The electrons can be injected externally or generated by the cathode via field emission governed by a current-field law. The initial zero current regime is replaced suddenly by injection or, in the case of field emission, by jumping the anode voltage from zero to a constant positive value. The case of equipotential electrodes and fixed injection is studied along with a positive anode potential. When the current is fixed externally, the approach to the stationary state goes without oscillations if the initial electron velocity is high enough and the anode can absorb the injected flow. Otherwise the accumulated space charge creates a potential barrier which reflects the flow and leads to its oscillations, but our method of analysis is invalid in such conditions. In the field emission case the flow goes to its stationary state through a train of decaying oscillations whose period is of the order of the electron transit time, in agreement with earlier studies based on perturbation techniques. Our approximate method does not permit very high cathode emissivity although the method works when the stationary current density is only about 10% smaller than the Child-Langmuir limit.

  2. 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. [BDM Petroleum Technologies, Bartlesville, OK (United States)

    1997-08-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

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

    2015-01-01T23:59:59.000Z

    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...

  4. Modeling the dynamics of tidally-interacting binary neutron stars up to merger

    E-Print Network [OSTI]

    Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

    2015-02-18T23:59:59.000Z

    The data analysis of the gravitational wave signals emitted by coalescing neutron star binaries requires the availability of an accurate analytical representation of the dynamics and waveforms of these systems. We propose an effective-one-body (EOB) model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to merger. Our EOB model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model energetics and the gravitational wave phasing with new high-resolution multi-orbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement within the uncertainty of the numerical data for all configurations. Our model is the first semi-analytical model which captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

  5. Regulation of Tidal and Wave Energy Projects (Maine)

    Broader source: Energy.gov [DOE]

    State regulation of tidal and wave energy projects is covered under the Maine Waterway Development and Conservation Act (MWDCA), and complements regulation by the Federal Energy Regulation...

  6. All Eyes on Eastport: Tidal Energy Project Brings Change, Opportunity...

    Office of Environmental Management (EM)

    Ocean Renewable Power Company will unveil its first commercial-scale tidal turbine before it is deployed underwater to generate power. The pilot project -- supported by...

  7. MINET: transient analysis of fluid-flow and heat-transfer networks

    SciTech Connect (OSTI)

    Van Tuyle, G.J.; Guppy, J.G.; Nepsee, T.C.

    1983-01-01T23:59:59.000Z

    MINET, a computer code developed for the steady-state and transient analysis of fluid-flow and heat-transfer networks, is described. The code is based on a momentum integral network method, which offers significant computational advantages in the analysis of large systems, such as the balance of plant in a power-generating facility. An application is discussed in which MINET is coupled to the Super System Code (SSC), an advanced generic code for the transient analysis of loop- or pool-type LMFBR systems. In this application, the ability of the Clinch River Breeder Reactor Plant to operate in a natural circulation mode following an assumed loss of all electric power, was assessed. Results from the MINET portion of the calculations are compared against those generated independently by the Clinch River Project, using the DEMO code.

  8. Analysis of the Loss of Forced Reactor Coolant Flow Accident in SMART using RETRAN-03/INT

    SciTech Connect (OSTI)

    Kim, Tae-Wan; Suh, Kune-Yull; Lee, Un-Chul; Park, Goon-Cherl [Department of Nuclear Engineering, Seoul National University, San 56-1, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of); Kim, Jae-Hak [Future and Challenge Co., LTD., 130-202, San 56-1, Shinlim-dong, Kwanak-gu, Seoul 151-742 (Korea, Republic of)

    2002-07-01T23:59:59.000Z

    Small and medium integral type nuclear reactors are getting much attention for the peaceful use of nuclear energy in non-electric area such as district heating, seawater desalination and ship propulsion. An integral type nuclear co-generation reactor, SMART(System-integrated Modular Advanced ReacTor, 330 MWt), has been developed by KAERI (Korea Atomic Energy Research Institute) since 1996. In this study, the safety analysis for SMART using modified RETRAN-03 code whose name is RETRAN-03/INT is performed to examine the applicability of RETRAN-03/INT code. For the safety analysis of integral reactor with helical-coiled steam generators, RETRAN-03 code has been modified and verified using experimental results. New heat transfer coefficients are added for helical-coiled steam generator. And, the heat transfer model for steam generator is modified due to the different primary and secondary side heat flow from U-tube type steam generator. The loss of forced reactor coolant flow accident is selected for safety analysis in this study. Also it is considered as a single failure that one of three trains of passive residual heat removal system is failed. The results from MARS/SMR code and RETRAN-03/INT code are compared. (authors)

  9. THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

    E-Print Network [OSTI]

    Guo, Jianheng

    By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass ...

  10. Analysis of Mass Flow and Enhanced Mass Flow Methods of Flashing Refrigerant-22 from a Small Vessel

    E-Print Network [OSTI]

    Nutter, Darin Wayne

    The mass flow characteristics of flashing Refrigerant-22 from a small vessel were investigated. A flash boiling apparatus was designed and built. It was modeled after the flashing process encountered by the accumulator of air-source heat pump...

  11. Linear analysis of time dependent properties of Child-Langmuir flow

    SciTech Connect (OSTI)

    Rokhlenko, A. [Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2013-01-15T23:59:59.000Z

    We continue our analysis of the time dependent behavior of the electron flow in the Child-Langmuir system, removing an approximation used earlier. We find a modified set of oscillatory decaying modes with frequencies of the same order as the inverse of the electron transient time. This range (typically MHz) allows simple experimental detection and maybe exploitation. We then study the time evolution of the current in response to a slow change of the anode voltage where the same modes of oscillations appear too. The cathode current in this case is systematically advanced or retarded depending on the direction of the voltage change.

  12. 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.

    2001-11-09T23:59:59.000Z

    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.

  13. 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 DataDepartment of Energy Your Density Isn'tOriginEducationVideoStrategic|Industrial Sector,Department ThirdCosts | Department ofTidal Energy

  14. Tidal Sails AS | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolarTharaldson Ethanol LLCEnergyoThornwood,TianfuTidal Sails AS Jump to:

  15. TidalStream | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin Hydropower Station Jump to: navigation, searchNewTidal

  16. 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.

    2012-12-29T23:59:59.000Z

    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

  17. Hydraulic Geometry and Microtopography of Tidal Freshwater Forested Wetlands and Implications for Restoration, Columbia River, U.S.A.

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Coleman, Andre M.; Borde, Amy B.; Sinks, Ian A.

    2008-01-01T23:59:59.000Z

    The hydrologic reconnection of tidal channels, riverine floodplains, and main stem channels are among responses by ecological restoration practitioners to the increasing fragmentation and land conversion occurring in coastal and riparian zones. Design standards and monitoring of such ecological restoration depend upon the characterization of reference sites that vary within and among regions. Few locales, such as the 235 km tidal portion of the Columbia River on the West Coast U.S.A., remain in which the reference conditions and restoration responses of tidal freshwater forested wetlands on temperate zone large river floodplains can be compared. This study developed hydraulic geometry relationships for Picea sitchensis (Sitka spruce) dominated tidal forests (swamps) in the vicinity of Grays Bay on the Columbia River some 37 km from the Pacific Coast using field surveys and Light Detection and Ranging (LiDAR) data. Scaling relationships between catchment area and the parameters of channel cross-sectional area at outlet and total channel length were comparable to tidally influenced systems of San Francisco Bay and the United Kingdom. Dike breaching, culvert replacement, and tide gate replacement all affected channel cross-sectional geometry through changes in the frequency of over-marsh flows. Radiocarbon dating of buried wood provided evidence of changes in sedimentation rates associated with diking, and restoration trajectories may be confounded by historical subsidence behind dikes rendering topographical relationships with water level incomparable to reference conditions. At the same time, buried wood is influencing the development of channel morphology toward characteristics resembling reference conditions. Ecological restoration goals and practices in tidal forested wetland regions of large river floodplains should reflect the interactions of these controlling factors.

  18. 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 power/3/07 Summary The principle that the net energy delivered by a tidal pool can be increased by pumping extra stop blowing for two days at a time? Chemical or kinetic­energy storage systems are an economical way

  19. Enhancing Electrical Supply by Pumped Storage in Tidal Lagoons

    E-Print Network [OSTI]

    MacKay, David J.C.

    to demand into high-value demand-following power; and second, it can simultaneously serve as a tidal power/3/07 Summary The principle that the net energy delivered by a tidal pool can be increased by pumping extra stop blowing for two days at a time? Chemical or kinetic-energy storage systems are an economical way

  20. Tidal Conversion at a Submarine Ridge FRANOIS PTRLIS

    E-Print Network [OSTI]

    Young, William R.

    that control the tidally powered radiation of in- ternal gravity waves (the "tidal conversion") from received 30 July 2003, in final form 20 January 2004) ABSTRACT The radiative flux of internal wave energy tide over submarine topography is a main source of the mechanical energy required to power the internal

  1. Directly Imaging Tidally Powered Migrating Jupiters

    E-Print Network [OSTI]

    Dong, Subo; Socrates, Aristotle

    2012-01-01T23:59:59.000Z

    We show that ongoing direct imaging experiments may detect a new class of long-period, highly luminous, tidally powered extrasolar gas giants. Even though they are hosted by Gyr-"old" main-sequence stars, they can be as "hot" as young Jupiters at ~100 Myr, the prime targets of direct imaging surveys. These planets, with years-long orbits, are presently migrating to "feed" the "hot Jupiters" in steady state. Their existence is expected from a class of "high-e" migration mechanisms, in which gas giants are excited to highly eccentric orbits and then shrink their semi-major axis by factor of ~ 10-100 due to tidal dissipation at successive close periastron passages. The dissipated orbital energy is converted to heat, and if it is deposited deep enough into the planet atmosphere, the planet likely radiates steadily at luminosity ~2-3 orders of magnitude larger than that of our Jupiter during a typical Gyr migration time scale. Their large orbital separations and expected high planet-to-star flux ratios in IR make ...

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

    SciTech Connect (OSTI)

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

    2011-10-01T23:59:59.000Z

    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.

  3. Oscillatory flow across an irregular boundary Geno Pawlak

    E-Print Network [OSTI]

    Pawlak, Geno

    ; KEYWORDS: eddies, tidal mixing, rough boundary, oscillatory flow, residual currents, wave boundary layers 1Oscillatory flow across an irregular boundary Geno Pawlak Department of Ocean and Resources. Introduction [2] Oscillatory flow past a rough boundary is a prevalent feature in a number of oceanographic

  4. A comparison of analog methods in heat flow analysis with simplified mathematica methods as applied to flight structures

    E-Print Network [OSTI]

    Murray, William

    1960-01-01T23:59:59.000Z

    in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE January 1960 Maj or Subj ect: Mechanical Engineering A COMPARISON OF ANALOG METHODS IN HEAT FLOW ANALYSIS WITH SIMPLIFIED MATHEMATICAL METHODS AS APPLIED TO FLIGHT STRUCTURES... and require lengthy and sometimes difficult mathematical computations to arrive at a solution. It is obvious that there is a need for a simple, rapid, and reliable method of solving complex problems involving heat flow. It is the purpose...

  5. Kinetic analysis of 18F-fluorodihydrorotenone as a deposited myocardial flow tracer: Comparison to thallium-201.

    SciTech Connect (OSTI)

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; O'Neil, James P.; La Belle, Michael; Huesman, Ronald H.; VanBrocklin, Henry F.

    2004-03-01T23:59:59.000Z

    The goal of this investigation was to assess the accuracy of 18F-fluorodihydrorotenone (18F-FDHR) as a new deposited myocardial flow tracer and compare the results to those for 201Tl. Methods. The kinetics of these flow tracers were evaluated in 22 isolated, erythrocyte- and albumin-perfused rabbit hearts over a flow range encountered in patients. The two flow tracers plus a vascular reference tracer (131I-albumin) were introduced as a bolus through a port just above the aortic cannula. Myocardial extraction, retention, washout, and uptake parameters were computed from the venous outflow curves using the multiple indicator dilution technique and spectral analysis. Results. The mean initial extraction fractions of 18F-FDHR (0.85 +- 0.07) and 201Tl (0.87 +- 0.05) were not significantly different, although the initial extraction fraction for 18F-FDHR declined with flow (P < 0.0001), whereas the initial extraction fraction of 201Tl did not. Washout of 201Tl was faster (P < 0.001) and more affected by flow (P < 0.05) than 18F-FDHR washout. Except for initial extraction fraction, 18F-FDHR retention was greater (P < 0.001) and less affected by flow (P < 0.05) than 201Tl retention. Reflecting its superior retention, net uptake of 18F-FDHR was better correlated with flow than 201Tl uptake at both one and fifteen minutes after tracer introduction (P < 0.0001 for both comparisons). Conclusion. The superior correlation of 18F-FDHR uptake with flow indicates that it is a better flow tracer than 201Tl in the isolated rabbit heart. Compared to the other currently available positron-emitting flow tracers (82Rb, 13N-ammonia, and 15O-water), 18F-FDHR has the potential of providing excellent image resolution without the need for an on-site cyclotron.

  6. 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)

    1995-11-01T23:59:59.000Z

    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.

  7. Viscous potential flow analysis of electrified miscible finitely conducting fluid through porous media

    SciTech Connect (OSTI)

    Obied Allah, M. H. [Department of Mathematics, Faculty of Science, Assiut University, Assiut (Egypt)

    2013-04-15T23:59:59.000Z

    In this work, a viscous potential flow analysis is used to investigate capillary surface waves between two horizontal finite fluid layers. The two layers have finite conductivities and admit mass and heat transfer. A general dispersion relation is derived. The presence of finite conductivities together with the dielectric permeabilities makes the horizontal electric field play a dual role in the stability criterion. The phenomenon of negative viscosity is observed. A new growth rate parameter, depending on the kinematical viscosity of the lower fluid layer, is found and has a stabilizing effect on the unstable modes. The growth rates and neutral stability curve are given and applied to air-water interface. The effects of various parameters are discussed for the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities.

  8. 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.

    2013-04-29T23:59:59.000Z

    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

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

    E-Print Network [OSTI]

    Austin, George Belden

    1953-01-01T23:59:59.000Z

    is not filling with sediment to any apparent degree. The U. S. Corps of Engineers maintains ths Mobile Ship Channel to a depth of thirty-two feet. Dredging operations proceed during most of the year since this depth is some twenty-two f'eet below the mean bay... ~ ~ ~ ~ ix ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 ~ 4 6 9 10 E. Meteorological III. TIDAL FLUSHING THEORY 15 A. Ketchum's Tidal Prism Theory B. Stommel's and Arons' Ydxing Length Theory. of Tidal Flushing IV. THE HYDROGRAPHIC SURVEY 22 27 A. Planning B...

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

    E-Print Network [OSTI]

    Austin, George Belden

    1953-01-01T23:59:59.000Z

    . For each of the twenty-eight station positions, curves vere then drawn for temperature-depth and salinity&epth for the different ob- served tidal stages. From these curves temperature-depth sections (Figure V) and salinity-depth sections (Figures VI, VII...) vere oon- structed 1' or six cross-sections of Mobile Bay and for the ship channel length, for the different tidal stages. Current velocity vectors were plotted by station for surface and bottom at ebb and flood tidal stages. From these data surface...

  11. NAME: Elkhorn Slough Tidal Marsh Restoration: Building Resilience with the Beneficial Reuse of Sediment

    E-Print Network [OSTI]

    US Army Corps of Engineers

    stormwater runoff. EXPECTED BENEFITS: Habitats, particularly tidal marsh, intertidal mudflat, and soft

  12. Numerical and Experimental Investigation of Tidal Current Energy Extraction 

    E-Print Network [OSTI]

    Sun, Xiaojing

    2008-01-01T23:59:59.000Z

    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. ...

  13. axis tidal turbines: Topics by E-print Network

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

    8 Power Limitation Control for a PMSG-Based Marine Current Turbine at High Tidal Speed and Physics Websites Summary: Power Limitation Control for a PMSG-Based Marine Current...

  14. analysing tidally induced: Topics by E-print Network

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

    15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Tidally-induced thermonuclear Supernovae Astrophysics (arXiv) Summary: We discuss the results of 3D simulations...

  15. Geomorphic structure of tidal hydrodynamics in salt marsh creeks

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    of the tidal signal within the marsh area. Citation: Fagherazzi, S., M. Hannion, and P. D'Odorico (2008 by elegant hydrological and geomorphological theories [Gupta et al., 1980; Rodriguez-Iturbe and Valdes, 1979

  16. 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.

    2014-06-07T23:59:59.000Z

    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.

  17. 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-

    2012-12-13T23:59:59.000Z

    if the large portion of the coolant flows into bypass gaps instead of coolant channels in which the cooling efficiency is much higher. A preliminary three dimensional steady-state CFD analysis was performed with commercial code STARCCM+ 6.04 to investigate...

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

    E-Print Network [OSTI]

    Zare, Richard N.

    fabrication techniques and the use of news materials has helped the field move toward its ultimate goal of producing low-cost, disposable instrumentation. Flow injection analysis (FIA) is a widely used sampling, Polydimethylsiloxane, Microvalves #12;3 The recent trend toward miniaturized chemical assays has led to the development

  19. Scheduling Design and Analysis for End-to-End Heterogeneous Flows in an Avionics Network

    E-Print Network [OSTI]

    Liu, Xue

    University of Science and Technology, Wuhan, China csyhua@hust.edu.cn Abstract--Avionics Full DupleX (AFDX heterogeneous flows, including avionics, multimedia (video & audio) and best-effort data flows, in an AFDX and sporadic flows in an AFDX prototype show the efficacy and efficiency of our proposed schemes. To the best

  20. Nonrotating black hole in a post-Newtonian tidal environment

    E-Print Network [OSTI]

    Stephanne Taylor; Eric Poisson

    2008-09-11T23:59:59.000Z

    We examine the motion and tidal dynamics of a nonrotating black hole placed within a post-Newtonian external spacetime. The tidal perturbation created by the external environment is treated as a small perturbation. At a large distance from the black hole, the gravitational field of the external distribution of matter is assumed to be sufficiently weak to be adequately described by the (first) post-Newtonian approximation to general relativity. There, the black hole is treated as a monopole contribution to the total gravitational field. There exists an overlap in the domains of validity of each description, and the black-hole and post-Newtonian metrics are matched in the overlap. The matching procedure produces the equations of motion for the black hole and the gravito-electric and gravito-magnetic tidal fields acting on the black hole. We first calculate the equations of motion and tidal fields by making no assumptions regarding the nature of the post-Newtonian environment; this could contain a continuous distribution of matter or any number of condensed bodies. We next specialize our discussion to a situation in which the black hole is a member of a post-Newtonian two-body system. As an application of our results, we examine the geometry of the deformed event horizon and calculate the tidal heating of the black hole, the rate at which it acquires mass as a result of its tidal interaction with the companion body.

  1. The tidal disruption of protoplanetary accretion discs

    E-Print Network [OSTI]

    John D. Larwood

    1997-05-30T23:59:59.000Z

    In this paper we revisit the problem of the tidal interaction occuring between a protostellar accretion disc and a secondary point mass following a parabolic trajectory. We model the disc response analytically and we compare our results with three-dimensional SPH simulations. Inviscid as well as viscous hydrodynamics is considered. We show that in a viscous system the response derived from inviscid considerations is predominant even for the highest estimates of an anomalous disc shear viscosity. The angular momentum lost from the disc during the encounter is derived from linear theory, for distant fly-bys, as well as the changes to the disc orientation expected in non-coplanar encounters. It is shown that the target discs can become warped and precess by a small amount during non-coplanar encounters. This small precession is shown to give rise to a relative tilt of the disc which is always more important for determining its final orientation than is the change to the orbital inclination. We discuss the implications of our results for protostellar accretion discs and planetary systems.

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

    E-Print Network [OSTI]

    White, Brian L., 1975-

    2006-01-01T23:59:59.000Z

    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 ...

  3. 1992 Columbia River Salmon Flow Measures Options Analysis/EIS : Appendices.

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    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.

  4. 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. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

    2006-07-01T23:59:59.000Z

    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)

  5. An analysis of an application of radioactive ionization for gas flow metering

    E-Print Network [OSTI]

    Lam, Carroll Frank

    1959-01-01T23:59:59.000Z

    OF FIGURES CHAP TER I. INTRODUCTION II. EXPERIMENTAL PROCEDURE III. MEASUREMENT OF MARK I CHARACTERISTICS IV. MEASUREMENT OF MARK II CHARACTERISTICS -3 V. CONCLUSIONS . 17 35 BIBLIOGRAPHY . 37 LIST OF FIGURES FIGURE PAGE 1. A Diagram of Rutherford...'s Apparatus Z. An Ezperimental Flow Meter . 3. Mark I Meter and Test Equipment 4. Electrical Circuit 5. Current vs. Flow Rate Curve for Mark I Meter. . . . . . . . . . . . . 6. Current vs. Flow Rate for DifferentSource Spacings. . . . . . . . . . 7...

  6. Mechanical analysis of a cross flow filter. Final report, January 31, 1995

    SciTech Connect (OSTI)

    NONE

    1998-12-31T23:59:59.000Z

    A cross flow filter for particulate control is described. Objectives were to improve the reliability and mechanical integrity of the filter.

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

    DOE Patents [OSTI]

    Ballard, E.O.

    1982-04-05T23:59:59.000Z

    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.

  8. Using Tidal Tails to Probe Dark Matter Halos

    E-Print Network [OSTI]

    John Dubinski; J. Christopher Mihos; Lars Hernquist

    1995-09-04T23:59:59.000Z

    We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the mass of dark halos in well-known merging pairs. We concentrate on prograde encounters between equal mass galaxies which represent the best cases for creating tidal tails, but also look at systems with different relative orientations, orbital energies and mass ratios. As the mass and extent of the dark halo increase in the model galaxies, the resulting tidal tails become shorter and less massive, even under the most favorable conditions for producing these features. Our simulations imply that the observed merging galaxies with long tidal tails ($\\sim 50-100$ kpc) such as NGC 4038/39 (the Antennae) and NGC 7252 probably have halo:disk+bulge mass ratios less than 10:1. These results conflict with the favored values of the dark halo mass of the Milky Way derived from satellite kinematics and the timing argument which give a halo:disk+bulge mass ratio of $\\sim 30:1$. However, the lower bound of the estimated dark halo mass in the Milky Way (mass ratio $\\sim 10:1$) is still consistent with the inferred tidal tail galaxy masses. Our results also conflict with the expectations of $\\Omega=1$ cosmologies such as CDM which predict much more massive and extended dark halos.

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

    E-Print Network [OSTI]

    Smerdon, Ernest T.; Blair, Allie W.

    areas were: a) development of a surge flow infiltration model; b) the effect Or wetted perimeter on infiltration in furrow; c) design, construction, and calibration of a physical model of an irrigation border/furrow; and d) development of a surge flow...

  10. Anisotropy and mantle flow in the Chile-Argentina subduction zone from shear wave splitting analysis

    E-Print Network [OSTI]

    Fouch, Matthew J.

    Anisotropy and mantle flow in the Chile-Argentina subduction zone from shear wave splitting subduction zone. Data is from the CHARGE network, which traversed Chile and western Argentina across two, M. L., G. Zandt, E. Triep, M. Fouch, and S. Beck (2004), Anisotropy and mantle flow in the Chile-Argentina

  11. Analysis of No-Flow Boundaries in Mixed Unconfined-Confined Aquifer Systems

    E-Print Network [OSTI]

    Langerlan, Kent A.

    2010-07-14T23:59:59.000Z

    investigated before and is the focus of this thesis. The objective of this thesis is to use both analytical and numerical modeling to investigate groundwater flow in an unconfined-confined aquifer including the no-flow lateral boundary effect and the regional...

  12. Bulk-Flow analysis for force and moment coefficients of a shrouded centrifugal compressor impeller

    E-Print Network [OSTI]

    Gupta, Manoj Kumar

    2005-08-29T23:59:59.000Z

    et al. (1996). The comparison shows that the shroud casing clearance flow and the fluid force moment can be simulated by the bulk flow model fairly well. An Iwatsubo-based labyrinth seal code developed by Childs and Scharrer (1986) is used...

  13. Crosstalk compensation in analysis of energy storage devices...

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

    Biomass and Biofuels Building Energy Efficiency Electricity Transmission Energy Analysis Energy Storage Geothermal Hydrogen and Fuel Cell Hydropower, Wave and Tidal Industrial...

  14. Kelvin-Helmholtz instability for flow in porous media under the influence of oblique magnetic fields: A viscous potential flow analysis

    SciTech Connect (OSTI)

    Moatimid, Galal M. [Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk, P.O. Box 741 (Saudi Arabia)] [Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk, P.O. Box 741 (Saudi Arabia); Obied Allah, M. H. [Department of Mathematics, Faculty of Science, Assiut University, Assiut (Egypt)] [Department of Mathematics, Faculty of Science, Assiut University, Assiut (Egypt); Hassan, Mohamed A. [Department of Mathematics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)] [Department of Mathematics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)

    2013-10-15T23:59:59.000Z

    In this paper, the Kelvin-Helmholtz instability of viscous incompressible magnetic fluid fully saturated porous media is achieved through the viscous potential theory. The flow is considered to be through semi-permeable boundaries above and below the fluids through which the fluid may either be blown in or sucked out, in a direction normal to the main streaming direction of the fluid flow. An oblique magnetic field, mass, heat transfer, and surface tension are present across the interface. Through the linear stability analysis, a general dispersion relation is derived and the natural curves are plotted. Therefore, the linear stability condition is discussed in some depth. In view of the multiple time scale technique, the Ginzburg–Landau equation, which describes the behavior of the system in the nonlinear approach, is obtained. The effects of the orientation of the magnetic fields on the stability configuration in linear, as well as nonlinear approaches, are discussed. It is found that the Darcy's coefficient for the porous layers plays a stabilizing role. The injection of the fluids at both boundaries has a stabilizing effect, in contrast with the suction at both boundaries.

  15. 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)

    2011-08-01T23:59:59.000Z

    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}.

  16. Resonant Oscillations and Tidal Heating in Coalescing Binary Neutron Stars

    E-Print Network [OSTI]

    Dong Lai

    1994-04-25T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of $10-100$ Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. However, since the coupling between the g-mode and the tidal potential is rather weak, the amount of energy transfer during a resonance and the induced orbital phase error are very small. Resonant excitations of the g-modes play an important role in tidal heating of binary neutron stars. Without the resonances, viscous dissipation is effective only when the stars are close to contact. The resonant oscillations result in dissipation at much larger orbital separation. The actual amount of tidal heating depends on the viscosity of the neutron star. Using the microscopic viscosity, we find that the binary neutron stars are heated to a temperature $\\sim 10^8$ K before they come into contact.

  17. 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.

    2015-01-01T23:59:59.000Z

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

  18. Sustainability of a Tidal Freshwater Marsh Exposed to a Long-term Hydrologic Barrier and Sea Level Rise

    E-Print Network [OSTI]

    Vermont, University of

    a tidal fresh- water marsh perpendicular to the Patuxent River (Maryland) channel has created a northern elevation change . Accretion . Tidal freshwater marsh . Seasonal sedimentation . Jug Bay . Patuxent River

  19. Methylmercury Production in Tidal Salt Marsh Sediments and Potential Control Using Iron Amendments

    E-Print Network [OSTI]

    Ulrich, Patrick D.

    2011-01-01T23:59:59.000Z

    Bay, a freshwater tidal mudflat wetland in the Hudson River.species that utilized tidal mudflat or open bay habitats (in forage fish that utilize mudflat and wetland habitats

  20. 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,...

  1. Relativistic tidal heating of Hamiltonian quasi-local boundary expressions

    E-Print Network [OSTI]

    So, Lau Loi

    2015-01-01T23:59:59.000Z

    Purdue and Favata calculate the tidal heating used certain classical pseudotensors. Booth and Creighton employed the quasi-local mass formalism of Brown and York to demonstrate the same subject. All of them give the result matched with the Newtonian theory. Here we present another Hamiltonian quasi-local boundary expressions and all give the same desired value. This indicates that the tidal heating is unique as Thorne predicted. Moreover, we discovered that the pseudo-tensor method and quasi-local method are fundamentally different.

  2. Relativistic tidal heating of Hamiltonian quasi-local boundary expressions

    E-Print Network [OSTI]

    Lau Loi So

    2015-05-19T23:59:59.000Z

    Purdue and Favata calculate the tidal heating used certain classical pseudotensors. Booth and Creighton employed the quasi-local mass formalism of Brown and York to demonstrate the same subject. All of them give the result matched with the Newtonian theory. Here we present another Hamiltonian quasi-local boundary expressions and all give the same desired value. This indicates that the tidal heating is unique as Thorne predicted. Moreover, we discovered that the pseudo-tensor method and quasi-local method are fundamentally different.

  3. A flow resistance model for assessing the impact of vegetation on flood routing mechanics

    E-Print Network [OSTI]

    Katul, Gabriel

    control in urban storm water runoff [Kirby et al., 2005], and linking tidal hydrodynamic forcing to flow and field studies. The proposed model asymptotically recovers the flow resistance formulation when the waterA flow resistance model for assessing the impact of vegetation on flood routing mechanics Gabriel G

  4. A numerical model for the coupled long-term evolution of salt marshes and tidal flats

    E-Print Network [OSTI]

    Fagherazzi, Sergio

    -shore mudflat model that takes into account tidal effects; Waeles et al. [2004] incor- porated in the same

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

    E-Print Network [OSTI]

    Scharfman, Barry Ethan

    2012-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Yan, Wenjin

    2013-05-06T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Abdou, Mohamed

    2007-01-01T23:59:59.000Z

    flow path design for an ITER solid breeder blanket module A. Yinga,, M. Narulaa, R. Hunta, M. Abdoua, Y breeder blanket design. Supplying all s the ITER test blanket module (TBM) warrants the need of extensive computer aided engineering (CAE

  8. 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 ...

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

    E-Print Network [OSTI]

    Zhen, Ling

    2006-04-12T23:59:59.000Z

    Particle Image Velocimetry (PIV) and pressure measurement techniques were performed to investigate the drag reduction due to microbubble injection in the boundary layer of a fully developed turbulent channel flow. ...

  10. A general nonlinear least squares data reconciliation and estimation method for material flow analysis

    E-Print Network [OSTI]

    Kopec, Grant M.; Allwood, Julian M.; Cullen, Jonathan M.; Ralph, Daniel

    2015-06-02T23:59:59.000Z

    reconciliation in problems with nonlinear constraints. This formulation relates measurements of flow rate, temperature, and pressure, so the specific equations may be less appropriate for MFA data reconciliation, though the basic methodology is applicable... to satisfy the structural constraints of mass flow and conservation of mass. For example, data from the World Steel Association (2010) indicates that 44.5 Mt of steel were used for welded tube in 2009, but the value that Cullen et al. (2012a) assign is 62...

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

    SciTech Connect (OSTI)

    Ralph Showalter; Malgorzata Peszynska

    2012-07-03T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Miller, Kathryn M.

    1990-01-01T23:59:59.000Z

    the effect of the gas and liquid mass flow rates, fluid properties, pipe diameter, angle of pipe inclination, and gravity. Five basic flow regimes were considered: smooth stratified, wavy stratified, intermittent (slug and plug), annular with dispersed... Numerical Solution The premise used in this work for solving for the transition boundary is based on the assumption that the transition from the stratified regime to some other regime will occur when a very small wave exists on the surface of the liquid...

  13. MSL F693 F01 French Tidal Power CRN # 36273 Station

    E-Print Network [OSTI]

    Kowalik, Zygmunt

    MSL F693 F01 French Tidal Power CRN # 36273 Station 3 CREDITS Zygmunt Kowalik A new course on TIDES. Such application has raised many questions about an environmental impact of tidal power development. The course a function of the changes in the sun- earth-moon system, caused by dissipation of the tidal energy

  14. TIDAL HEATING OF EXTRASOLAR PLANETS Brian Jackson, Richard Greenberg, and Rory Barnes

    E-Print Network [OSTI]

    Barnes, Rory

    TIDAL HEATING OF EXTRASOLAR PLANETS Brian Jackson, Richard Greenberg, and Rory Barnes Lunar and gas cleared away, and as the orbits evolved there was substantial tidal heating within the planets. The tidal heating history of each planet may have contributed significantly to the thermal budget governing

  15. Tidally averaged circulation in Puget Sound sub-basins: Comparison of historical data, analytical model, and numerical model

    SciTech Connect (OSTI)

    Khangaonkar, Tarang; Yang, Zhaoqing; Kim, Tae Yun; Roberts, Mindy

    2011-07-20T23:59:59.000Z

    Through extensive field data collection and analysis efforts conducted since the 1950s, researchers have established an understanding of the characteristic features of circulation in Puget Sound. The pattern ranges from the classic fjordal behavior in some basins, with shallow brackish outflow and compensating inflow immediately below, to the typical two-layer flow observed in many partially mixed estuaries with saline inflow at depth. An attempt at reproducing this behavior by fitting an analytical formulation to past data is presented, followed by the application of a three-dimensional circulation and transport numerical model. The analytical treatment helped identify key physical processes and parameters, but quickly reconfirmed that response is complex and would require site-specific parameterization to include effects of sills and interconnected basins. The numerical model of Puget Sound, developed using unstructured-grid finite volume method, allowed resolution of the sub-basin geometric features, including presence of major islands, and site-specific strong advective vertical mixing created by bathymetry and multiple sills. The model was calibrated using available recent short-term oceanographic time series data sets from different parts of the Puget Sound basin. The results are compared against (1) recent velocity and salinity data collected in Puget Sound from 2006 and (2) a composite data set from previously analyzed historical records, mostly from the 1970s. The results highlight the ability of the model to reproduce velocity and salinity profile characteristics, their variations among Puget Sound subbasins, and tidally averaged circulation. Sensitivity of residual circulation to variations in freshwater inflow and resulting salinity gradient in fjordal sub-basins of Puget Sound is examined.

  16. 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 of new tools produced by the Center for Coastal Resources Managment (CCRM) and other programs) technology with digital aerial photographs and the power of the Internet. They are accessible from desktop

  17. Tidal Stage Variability of Fecal Coliform and Chlorophyll a

    E-Print Network [OSTI]

    Mallin, Michael

    leachates, leaking sewer mains, wild and do- mestic animal wastes, and runo. However, the inter- action environmental hazards, to enter an estuarine environment characterized by high variability regarding temperature to understanding both the basic ecology of tidal creeks and the applied aspects of sampling protocols and pollutant

  18. Large-scale tidal fields on primordial density perturbations ?

    E-Print Network [OSTI]

    Alejandro Gonzalez

    1997-02-17T23:59:59.000Z

    We calculate the strength of the tidal field produced by the large-scale density field acting on primordial density perturbations in power law models. By analysing changes in the orientation of the deformation tensor, resulted from smoothing the density field on different mass scales, we show that the large-scale tidal field can strongly affect the morphology and orientation of density peaks. The measure of the strength of the tidal field is performed as a function of the distance to the peak and of the spectral index. We detected evidence that two populations of perturbations seems to coexist; one, with a misalignment between the main axes of their inertia and deformation tensors. This would lead to the angular momentum acquisition and morphological changes. For the second population, the perturbations are found nearly aligned in the direction of the tidal field, which would imprint them low angular momentum and which would allow an alignment of structures as those reported between clusters of galaxies in filaments, and between galaxies in clusters. Evidence is presented that the correlation between the orientation of perturbations and the large-scale density field could be a common property of Gaussian density fields with spectral indexes $n < 0$. We argue that alignment of structures can be used to probe the flatness of the spectrum on large scales but it cannot determine the exact value of the spectral index.

  19. Pasture and Soil Management Following Tidal Saltwater Intrusion

    E-Print Network [OSTI]

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

    2009-05-26T23:59:59.000Z

    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....

  20. Overview of Ocean Wave and Tidal Energy Lingchuan Mei

    E-Print Network [OSTI]

    Lavaei, Javad

    Overview of Ocean Wave and Tidal Energy Lingchuan Mei Department of Electrical Engineering Columbia with the climate change has led us to the exploration of new renewable energy in the past few decades. Oceans of this paper is to briefly overview the technology development of the ocean energy exploration, focusing on two

  1. Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model

    SciTech Connect (OSTI)

    Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Abidin, Zainal [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2010-12-23T23:59:59.000Z

    Radioactive tracer {sup 82}Br in the form of KBr-82 with activity {+-} 1 mCi has been injected into steel pipeline to qualify the extent dispersion of water flowing inside it. Internal diameter of the pipe is 3 in. The water source was originated from water tank through which the water flow gravitically into the pipeline. Two collimated sodium iodide detectors were used in this experiment each of which was placed on the top of the pipeline at the distance of 8 and 11 m from injection point respectively. Residence time distribution (RTD) curves obtained from injection of tracer are elaborated numerically to find information of the fluid flow properties. The transit time of tracer calculated from the mean residence time (MRT) of each RTD curves is 14.9 s, therefore the flow velocity of the water is 0.2 m/s. The dispersion number, D/uL, for each RTD curve estimated by using axial dispersion model are 0.055 and 0.06 respectively. These calculations are performed after fitting the simulated axial dispersion model on the experiment curves. These results indicated that the extent of dispersion of water flowing in the pipeline is in the category of intermediate.

  2. 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)

    1999-06-01T23:59:59.000Z

    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.}

  3. 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.

    1990-05-01T23:59:59.000Z

    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.

  4. 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

    2013-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Rahmani, Amir M; Jupiterwala, Mehlam; Colosqui, Carlos E

    2015-01-01T23:59:59.000Z

    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 displace...

  6. 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)

    2005-01-01T23:59:59.000Z

    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.

  7. 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)

    2012-05-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Shilling, Roy Bryant

    1978-01-01T23:59:59.000Z

    , both the pump and the test di scharge pipe were mounted on a carriage whiLh oscil]ated on the track above a water sump. They were connected from the suction end by two-inch I. D. gal- vanized pipe joined in the center by a 1. 5 inch orifice plate... SPECTRUM AT 3. 5 HZ, EMPTY PIPE . FORCED VIBRATION SPECTRUM AT 3. 5 HZ, 47 fps FLOW VELOCITY- FROCED VIBRATION SPECTRUM AT 4. 58 HZ EMPTY PIPE . FORCED VIBRATION SPECTRUM AT 4. 58 HZ 10 fps FLOW VELOCITY . MIDRANGE DYNAMICS . INTENSITY RESPONSE...

  9. Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets

    E-Print Network [OSTI]

    Whilden, Kerri Ann

    2010-10-12T23:59:59.000Z

    of the secondary structures into the vortex system are shown as well as variations in characteristics such as trajectory, size, vorticity, and circulation for the vortices as they move downstream. iv To the loved ones who have encouraged me along the way. v.... : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 30 13 Non-Dimensional Vorticity at the Swirl Strength Peak for the Pri- mary Vortex Within the Vortex System Versus Non-Dimensional Horizontal Location of the Centroid. : : : : : : : : : : : : : : : : : : 31 14 Non-Dimensional Circulation...

  10. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here. Category:Conceptual Model Add.png Add aTechniquesand Aliasespage?

  11. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE FacilityDimondale,South,Earlsboro, Oklahoma: EnergyEnergy Information

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

    SciTech Connect (OSTI)

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

    2014-09-30T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Amini, Noushin

    2012-02-14T23:59:59.000Z

    through the core of an annular pebble bed VHTR. The complex geometry of the core and the highly turbulent nature of the coolant flow passing through the gaps of fuel pebbles make this case quite challenging. In this experiment, a high frequency Hot Wire...

  14. Analysis of Compressible and Incompressible Flows Through See-through Labyrinth Seals

    E-Print Network [OSTI]

    Woo, Jeng Won

    2011-08-08T23:59:59.000Z

    of the working fluid through the labyrinth seal is desirable because it improves the efficiency of the turbomachine. The carry-over coefficient, based on the divergence angle of the jet, changed with flow parameters with fixed seal geometry while earlier models...

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

    E-Print Network [OSTI]

    Yan, Wenjin

    2013-05-06T23:59:59.000Z

    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...

  16. A FAMILY OF STEADY TWO-PHASE GENERALIZED FORCHHEIMER FLOWS AND THEIR LINEAR STABILITY ANALYSIS

    E-Print Network [OSTI]

    to the additional nonlinearity in the momentum equation. For example, unlike the Darcy flows, there is no Kruzkov in porous media using generalized Forchheimer equations and the capillary pressure. Firstly, we find stability of those steady states. The linearized system is derived and reduced to a parabolic equation

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

    E-Print Network [OSTI]

    Zhen, Ling

    2006-04-12T23:59:59.000Z

    with single phase channel flow characteristics. A drag reduction of 38.4% was achieved with void fraction of 4.9%. The measurements were analyzed by studying the turbulence characteristics utilizing wavelet techniques. The wavelet cross-correlation and auto...

  18. Stochastic analysis of transient flow to a well in a heterogeneous aquifer

    E-Print Network [OSTI]

    Kurien, Susan

    of Arizona) Mentors: Shlomo P. Neuman (U of Arizona) Daniel Tartakovsky (LANL-T7) Introduction of potable water on Earth. The term groundwater is usually used to describe water that is beneath the water groundwater flow are generally uncertain in their exact nature, magnitude, and spatio- temporal distribution

  19. Fluid flow near reservoir lakes inferred from the spatial and temporal analysis of the electric potential

    E-Print Network [OSTI]

    Adolphs, Ralph

    , 2002. 1. Introduction [2] Detecting subsurface groundwater circulation using geophysical methods to result from the electrokinetic coupling associated with a vertical groundwater flow connecting a constant pore pressure source to the bottom of the lakes. Numerical modeling indicates that the spatial

  20. A stochastic analysis of transient two-phase flow in heterogeneous porous media

    E-Print Network [OSTI]

    Lu, Zhiming

    the finite element heat and mass (FEHM) transfer code, whose results are considered ``true'' solutions equation (KLME) approach is implemented to model stochastic transient water-NAPL two-phase flow model and Parker and Lenhard models are adopted. The log-transformed intrinsic permeability, soil pore

  1. 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

    2009-01-01T23:59:59.000Z

    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.

  2. DNS of vertical plane channel flow with finite-size particles: Voronoi analysis, acceleration statistics and particle-conditioned averaging

    E-Print Network [OSTI]

    Garcia-Villalba, Manuel; Uhlmann, Markus

    2012-01-01T23:59:59.000Z

    We have performed a direct numerical simulation of dilute turbulent particulate flow in a vertical plane channel, fully resolving the phase interfaces. The flow conditions are the same as those in the main case of "Uhlmann, M., Phys. Fluids, vol. 20, 2008, 053305", with the exception of the computational domain length which has been doubled in the present study. The statistics of flow and particle motion are not significantly altered by the elongation of the domain. The large-scale columnar-like structures which had previously been identified do persist and they are still only marginally decorrelated in the prolonged domain. Voronoi analysis of the spatial particle distribution shows that the state of the dispersed phase can be characterized as slightly more ordered than random tending towards a homogeneous spatial distribution. It is also found that the p.d.f.'s of Lagrangian particle accelerations for wall-normal and spanwise directions follow a lognormal distribution as observed in previous experiments of ...

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

    E-Print Network [OSTI]

    Euaggelos E. Zotos

    2014-11-18T23:59:59.000Z

    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.

  4. 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

    2015-04-13T23:59:59.000Z

    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.

  5. Drag Reduction Study by Wavelet Analysis of Differential Pressure Signals in Turbulent Flow

    SciTech Connect (OSTI)

    Ling Zhen; Yassin, A. Hassan; Dominguez-Ontiveros, Elvis [Nuclear Engineering Department, Texas A and M University, College Station, Texas 77843 (United States)

    2004-07-01T23:59:59.000Z

    Drag reduction was studied when micro-bubbles with low void fractions were injected in the boundary layer of a turbulent channel flow. The particle tracking velocimetry (PIV) flow measurement technique was used to measure two-dimensional full velocity fields. Since pressure field distribution is associated with turbulence behavior and dissipation, it is important to study the changes of the pressure field. However, the differential pressure signals are difficult to analyze due to irregularity. The characteristics of these signals have been studied by traditional statistical methods. In this study, the multi-resolution technique of wavelet transform based on localized wavelet functions is utilized to nonlinear pressure signals. By using continuous wavelet transform method, the pressure signals in the turbulent flow can be decomposed into its approximations and details at different resolutions. The magnitudes of the coefficients represent the energy distribution at different scales and this also can facilitate the visual observation of the energy transition process. The wavelet decomposition coefficients at different scales plot would provide a tool to further our understanding of drag reduction mechanism via micro-bubbles injection. (authors)

  6. Analysis of the flow imbalance on the profile shape during the extrusion of thin magnesium sheets

    SciTech Connect (OSTI)

    Gall, Sven [Forschungszentrum Strangpressen, Technische Universität Berlin, Gustav-Meyer-Allee 25, Berlin, 13355, Germany, and Metallische Werkstoffe, Technische Universität Berlin, Ernst-Reuter-Platz 1, Berlin, 10587 (Germany); Müller, Sören [Forschungszentrum Strangpressen, Technische Universität Berlin, Gustav-Meyer-Allee 25, Berlin, 13355 (Germany); Reimers, Walter [Metallische Werkstoffe, Technische Universität Berlin, Ernst-Reuter-Platz 1, Berlin, 10587 (Germany)

    2013-12-16T23:59:59.000Z

    The extrusion process facilitates the production of magnesium sheets featuring a very thin thickness as well as excellent surface properties by using a single process step only. However, the extrusion of the magnesium sheets applying not optimized process parameters, e.g. low billet temperature or/ and poorly deformable magnesium alloy, produce pronounced buckling and waving of the extruded sheets as well as a variation of accuracy in profile shape along the cross section. The present investigation focuses on the FEM-simulation of the extrusion of magnesium sheets in order to clarify the origin of the mentioned effects. The simulations identify the flow imbalance during extrusion as the main critical factor. Due to the flow imbalance after passing the die a large compression stress zone is formed causing the buckling and waving of the thin sheets. Furthermore, the simulations of the magnesium sheet extrusion reveal that the interaction of the material flow gradients along the width and along the thickness direction near the die orifice lead to the variation of the accuracy in profile shape.

  7. 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

    2006-02-16T23:59:59.000Z

    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.

  8. 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

  9. Full field automated flow analysis of a spray using digital pulsed laser velocimetry

    E-Print Network [OSTI]

    Delahunte, Katey Eileen

    1991-01-01T23:59:59.000Z

    . . The MV image double B. The MV image double C. . Target grid for the EP doubles. . . Target grid for the EP singles. The EP image double 11. The EP image single 11. The EP image double 12. Page 35 36 36 39 40 41 42 43 44 45 47 47 48 51.... The EP image single 13. . The EP image double 14, The EP image single 14. Target grid for the analysis of EP doubles. Target grid for the analysis of EP singles. Region of EP double 11 used for analysis. Region of EP single 11 used for analysis...

  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.

    2012-07-01T23:59:59.000Z

    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.

    2011-07-01T23:59:59.000Z

    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. Spatial motion of the Magellanic Clouds. Tidal models ruled out?

    E-Print Network [OSTI]

    Ruzicka, Adam; Palous, Jan

    2008-01-01T23:59:59.000Z

    Recently, Kallivayalil et al. derived new values of the proper motion for the Large and Small Magellanic Clouds (LMC and SMC, respectively). The spatial velocities of both Clouds are unexpectedly higher than their previous values resulting from agreement between the available theoretical models of the Magellanic System and the observations of neutral hydrogen (HI) associated with the LMC and the SMC. Such proper motion estimates are likely to be at odds with the scenarios for creation of the large-scale structures in the Magellanic System suggested so far. We investigated this hypothesis for the pure tidal models, as they were the first ones devised to explain the evolution of the Magellanic System, and the tidal stripping is intrinsically involved in every model assuming the gravitational interaction. The parameter space for the Milky Way (MW)-LMC-SMC interaction was analyzed by a robust search algorithm (genetic algorithm) combined with a fast restricted N-body model of the interaction. Our method extended ...

  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. Orbital motions as gradiometers for post-Newtonian tidal effects

    E-Print Network [OSTI]

    Lorenzo Iorio

    2014-07-31T23:59:59.000Z

    The direct long-term changes occurring in the orbital dynamics of a local gravitationally bound binary system $S$ due to the post-Newtonian tidal acceleration caused by an external massive source are investigated. A class of systems made of a test particle $m$ rapidly orbiting with orbital frequency $n_{\\rm b}$ an astronomical body of mass $M$ which, in turn, slowly revolves around a distant object of mass $M^{'}$ with orbital frequency $n_{\\rm b}^{'}\\ll n_{\\rm b}$ is considered. The characteristic frequencies of the non-Keplerian orbital variations of $m$ and of $M$ itself are assumed to be negligible with respect to both $n_{\\rm b}$ and $n_{\\rm b}^{'}$. General expressions for the resulting Newtonian and post-Newtonian tidal orbital shifts of $m$ are obtained. The future missions BepiColombo and JUICE to Mercury and Ganymede, respectively, are considered in view of a possible detection. The largest effects, of the order of $\\approx 0.1-0.5$ milliarcseconds per year (mas yr$^{-1}$), occur for the Ganymede orbiter of the JUICE mission. Although future improvements in spacecraft tracking and orbit determination might, perhaps, reach the required sensitivity, the systematic bias represented by the other known orbital perturbations of both Newtonian and post-Newtonian origin would be overwhelming. The realization of a dedicated artificial mini-planetary system to be carried onboard and Earth-orbiting spacecraft is considered as well. Post-Newtonian tidal precessions as large as $\\approx 1-10^2$ mas yr$^{-1}$ could be obtained, but the quite larger Newtonian tidal effects would be a major source of systematic bias because of the present-day percent uncertainty in the product of the Earth's mass times the Newtonian gravitational parameter.

  15. Investigation of tidal power, Cobscook Bay, Maine. Environmental Appendix

    SciTech Connect (OSTI)

    Not Available

    1980-08-01T23:59:59.000Z

    This report presents information regarding existing terrestrial and marine resources and water quality conditions in the Cobscook Bay area. A preliminary assessment of impacts from a tidal power project is also presented and data gaps are identified. Reports contained in the appendix were prepared by the U.S. Fish and Wildlife Service, the National Marine Fisheries Service, the University of Maine at Orino, School of Forestry Resources and the U.S. Army Corps of Engineers.

  16. Modeling Tidal Streams in evolving dark matter halos

    E-Print Network [OSTI]

    Jorge Penarrubia; Andrew J. Benson; David Martinez-Delgado; Hans-Walter Rix

    2005-12-20T23:59:59.000Z

    We explore whether stellar tidal streams can provide information on the secular, cosmological evolution of the Milky Way's gravitational potential and on the presence of subhalos. We carry out long-term (~t_hubble) N-body simulations of disrupting satellite galaxies in a semi-analytic Galaxy potential where the dark matter halo and the subhalos evolve according to a LCDM cosmogony. All simulations are constrained to end up with the same position and velocity at present. Our simulations account for: (i) the secular evolution of the host halo's mass, size and shape, (ii) the presence of subhalos and (iii) dynamical friction. We find that tidal stream particles respond adiabatically to the Galaxy growth so that, at present, the energy and angular momentum distribution is exclusively determined by the present Galaxy potential. In other words, all present-day observables can only constrain the present mass distribution of the Galaxy independent of its past evolution. We also show that, if the full phase-space distribution of a tidal stream is available, we can accurately determine (i) the present Galaxy's shape and (ii) the amount of mass loss from the stream's progenitor, even if this evolution spanned a cosmologically significant epoch.

  17. Resonant oscillations and tidal heating in coalescing binary neutron stars

    E-Print Network [OSTI]

    Lai, D

    1994-01-01T23:59:59.000Z

    Tidal interaction in a coalescing neutron star binary can resonantly excite the g-mode oscillations of the neutron star when the frequency of the tidal driving force equals the intrinsic g-mode frequencies. We study the g-mode oscillations of cold neutron stars using recent microscopic nuclear equations of state, where we determine self-consistently the sound speed and Brunt-V\\"ais\\"al\\"a frequency in the nuclear liquid core. The properties of the g-modes associated with the stable stratification of the core depend sensitively on the pressure-density relation as well as the symmetry energy of the dense nuclear matter. The frequencies of the first ten g-modes lie approximately in the range of 10-100 Hz. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. The angular momentum transfer is possible because a dynamical tidal lag develops even in the absence of fluid viscosity. ...

  18. The mass-metallicity relation of tidal dwarf galaxies

    E-Print Network [OSTI]

    Recchi, S; Ploeckinger, S

    2015-01-01T23:59:59.000Z

    Dwarf galaxies generally follow a mass-metallicity (MZ) relation, where more massive objects retain a larger fraction of heavy elements. Young tidal dwarf galaxies (TDGs), born in the tidal tails produced by interacting gas-rich galaxies, have been thought to not follow the MZ relation, because they inherit the metallicity of the more massive parent galaxies. We present chemical evolution models to investigate if TDGs that formed at very high redshifts, where the metallicity of their parent galaxy was very low, can produce the observed MZ relation. Assuming that galaxy interactions were more frequent in the denser high-redshift universe, TDGs could constitute an important contribution to the dwarf galaxy population. The survey of chemical evolution models of TDGs presented here captures for the first time an initial mass function (IMF) of stars that is dependent on both the star formation rate and the gas metallicity via the integrated galactic IMF (IGIMF) theory. As TDGs form in the tidal debris of interacti...

  19. 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.

    1982-09-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Shilling, Roy Bryant

    1978-01-01T23:59:59.000Z

    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...

  1. 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.

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

    E-Print Network [OSTI]

    Hoffman, Joe Douglas

    1959-01-01T23:59:59.000Z

    in available energy, The heat, Q, entering or leaving the system is also a loss of available mechanical energy from the system. Defining K , the increase in unavailable energy, as follows, EL-- (u2-ul) -Q, the energy balance now becomes V 2 V 2 Pl P2...=AV where Q is the volumetric rate of flow, and A is the cross sec- tional area of the pipe, Hence, A 2 x D Substituting this value of V, the following results. ~6. ) ~ ~. g), Defining k in the following manner ~6?(g(u) the relationship between...

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral20ALSNewstt^ \ #ANUDlSiTM-40 Load Flow

  4. 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.

    2010-01-01T23:59:59.000Z

    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

  5. 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)

    2010-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    Kwon, Soon-Bum; Lee, Dong-Won [Department of Mechanical Engineering, Kyungpook National University, 1370, Sankyuk-dong, Daegu 702-701 (Korea, Republic of); Kim, In-Goo; Ahn, Hyung-Joon; Kim, Hho-Jung [Korea Institute of Nuclear Safety, 19, Kusungdong, Yousungku, Daejon 305-338 (Korea, Republic of)

    2004-07-01T23:59:59.000Z

    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)

  7. Analysis of Fault Permeability Using Mapping and Flow Modeling, Hickory Sandstone Aquifer, Central Texas

    SciTech Connect (OSTI)

    Nieto Camargo, Jorge E., E-mail: jorge.nietocamargo@aramco.com; Jensen, Jerry L., E-mail: jjensen@ucalgary.ca [University of Calgary, Department of Chemical and Petroleum Engineering (Canada)

    2012-09-15T23:59:59.000Z

    Reservoir compartments, typical targets for infill well locations, are commonly created by faults that may reduce permeability. A narrow fault may consist of a complex assemblage of deformation elements that result in spatially variable and anisotropic permeabilities. We report on the permeability structure of a km-scale fault sampled through drilling a faulted siliciclastic aquifer in central Texas. Probe and whole-core permeabilities, serial CAT scans, and textural and structural data from the selected core samples are used to understand permeability structure of fault zones and develop predictive models of fault zone permeability. Using numerical flow simulation, it is possible to predict permeability anisotropy associated with faults and evaluate the effect of individual deformation elements in the overall permeability tensor. We found relationships between the permeability of the host rock and those of the highly deformed (HD) fault-elements according to the fault throw. The lateral continuity and predictable permeability of the HD fault elements enhance capability for estimating the effects of subseismic faulting on fluid flow in low-shale reservoirs.

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

    E-Print Network [OSTI]

    Ketcham, Jerod W

    2010-01-01T23:59:59.000Z

    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 ...

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

    DOE Patents [OSTI]

    West, Jason A. A.; Hukari, Kyle W.; Patel, Kamlesh D.; Peterson, Kenneth A.; Renzi, Ronald F.

    2013-04-23T23:59:59.000Z

    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.

  10. 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)

    2009-09-22T23:59:59.000Z

    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.

  11. Tidal Heating of Terrestrial Extra-Solar Planets and Implications for their Habitability

    E-Print Network [OSTI]

    Brian Jackson; Rory Barnes; Richard Greenberg

    2008-08-20T23:59:59.000Z

    The tidal heating of hypothetical rocky (or terrestrial) extra-solar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate sub-surface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to the formation and replenishment of a planet's atmosphere. To address these issues, we model the tidal heating and evolution of hypothetical extra-solar terrestrial planets. The results presented here constrain the orbital and physical properties required for planets to be habitable.

  12. 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)

    2014-02-01T23:59:59.000Z

    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.

  13. NUMERICAL ANALYSIS OF VAPOR BUBBLE GROWTH AND WALL HEAT TRANSFER DURING FLOW BOILING OF WATER IN A MICROCHANNEL

    E-Print Network [OSTI]

    Kandlikar, Satish

    . (2004) developed three- zone flow boiling heat transfer model to describe evaporation of elongated

  14. Validation Analysis of the Groundwater Flow and Transport Model of the Central Nevada Test Area

    SciTech Connect (OSTI)

    A. Hassan; J. Chapman; H. Bekhit; B. Lyles; K. Pohlmann

    2006-09-30T23:59:59.000Z

    The Central Nevada Test Area (CNTA) is a U.S. Department of Energy (DOE) site undergoing environmental restoration. The CNTA is located about 95 km northeast of Tonopah, Nevada, and 175 km southwest of Ely, Nevada (Figure 1.1). It was the site of the Faultless underground nuclear test conducted by the U.S. Atomic Energy Commission (DOE's predecessor agency) in January 1968. The purposes of this test were to gauge the seismic effects of a relatively large, high-yield detonation completed in Hot Creek Valley (outside the Nevada Test Site [NTS]) and to determine the suitability of the site for future large detonations. The yield of the Faultless underground nuclear test was between 200 kilotons and 1 megaton (DOE, 2000). A three-dimensional flow and transport model was created for the CNTA site (Pohlmann et al., 1999) and determined acceptable by DOE and the Nevada Division of Environmental Protection (NDEP) for predicting contaminant boundaries for the site.

  15. Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary and Their Implications for Managing River Flows and Restoring Estuarine Habitat, Physical Sciences Component, Progress Report.

    SciTech Connect (OSTI)

    Jay, David A. [Portland State University

    2009-08-03T23:59:59.000Z

    Long-term changes and fluctuations in river flow, water properties, tides, and sediment transport in the Columbia River and its estuary have had a profound effect on Columbia River salmonids and their habitat. Understanding the river-flow, temperature, tidal, and sediment-supply regimes of the Lower Columbia River (LCR) and how they interact with habitat is, therefore, critical to development of system management and restoration strategies. It is also useful to separate management and climate impacts on hydrologic properties and habitat. This contract, part of a larger project led by the National Oceanic and Atmospheric Administration (NOAA), consists of three work elements, one with five tasks. The first work element relates to reconstruction of historic conditions in a broad sense. The second and third elements consist, respectively, of participation in project-wide integration efforts, and reporting. This report focuses on the five tasks within the historic reconstruction work element. It in part satisfies the reporting requirement, and it forms the basis for our participation in the project integration effort. The first task consists of several topics related to historic changes in river stage and tide. Within this task, the chart datum levels of 14 historic bathymetric surveys completed before definition of Columbia River Datum (CRD) were related to CRD, to enable analysis of these surveys by other project scientists. We have also modeled tidal datums and properties (lower low water or LLW, higher high water or HHW, mean water level or MWL, and greater diurnal tidal range or GDTR) as a function of river flow and tidal range at Astoria. These calculations have been carried for 10 year intervals (1940-date) for 21 stations, though most stations have data for only a few time intervals. Longer-term analyses involve the records at Astoria (1925-date) and Vancouver (1902-date). Water levels for any given river flow have decreased substantially (0.3-1.8 m, depending on river flow and tidal range), and tidal ranges have increased considerably (by a factor of 1.5 to 4 for most river-flow levels) since the 1900-1940 period at most stations, with the largest percentage changes occurring at upriver stations. These changes have been caused by a combination of changes in channel roughness, shape and alignment, changes in coastal tides, and (possibly) bed degradation. Tides are growing throughout the Northeast Pacific, and Astoria (Tongue Pt) has one of the most rapid rates of increase in tidal range in the entire Eastern Pacific, about 0.3m per century. More than half of this change appears to result from changes within the system, the rest from larger scale changes in coastal tides. Regression models of HHW have been used to estimate daily shallow water habitat (SWHA) available in a {approx}25 mile long reach of the system from Eagle Cliff to Kalama for 1925-2004 under four different scenarios (the four possible combinations of diked/undiked and observed flow/ virgin flow). More than 70% of the habitat in this reach has been lost (modern conditions vs. virgin flow with not dikes). In contrast, however, to the reach between Skamokawa and Beaver, selective dike removal (instead of a combination of dike removal and flow restoration) would suffice to increase spring SWHA. The second task consists of reconstruction of the hydrologic cycle before 1878, based on historic documents and inversion of tidal data collected before the onset of the historic flow record in 1878. We have a complete list of freshet times and peak flows for 1858-1877, and scattered freshet information for 1841-1857. Based on tidal data, we have reconstructed the annual flow cycles for 1870 and 1871; other time periods between 1854 and 1867 are under analysis. The three remaining tasks relate to post-1878 hydrologic conditions (flows, sediment supply and water temperature), and separation of the human and climate influences thereon. Estimated ob-served (sometimes routed), adjusted (corrected for reservoir manipulation) and virgin (corrected also for irrigation div

  16. Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD

    SciTech Connect (OSTI)

    Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

    2010-03-15T23:59:59.000Z

    This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

  17. The Unusual Tidal Dwarf Candidate in the Merger System NGC 3227/6: Star Formation in a Tidal Shock?

    E-Print Network [OSTI]

    Carole G. Mundell; Phil A. James; Nora Loiseau; Eva Schinnerer; Duncan A. Forbes; ;

    2004-07-07T23:59:59.000Z

    We report the discovery of active star formation in the HI cloud associated with the interacting Seyfert system NGC 3227/NGC 3226 that was originally identified as a candidate tidal dwarf galaxy (TDG) by Mundell et al. and that we name J1023+1952. We present the results of broad-band BRIJHK and ultraviolet imaging that show the HI cloud is associated with massive on-going star formation seen as a cluster of blue knots (M_B < -15.5 mag) surrounded by a diffuse ultraviolet halo and co-spatial with a ridge of high column density neutral hydrogen its southern half. We also detect Ha emission from the knots with a flux density corresponding to a star-formation rate of SFR~0.011 Msun per yr. Although J1023+1952 spatially overlaps the edge of the disk of NGC 3227, it has a mean HI velocity 150 km/s higher than that of NGC 3227 so is kinematically distinct; comparison of ionized and neutral gas kinematics in the star-forming region show closely matched velocities, providing strong evidence that the knots are embedded in J1023+1952 and do not merely lie behind in the disk of NGC 3227, thus confirming J1023+1952 as a gas-rich dwarf galaxy. We discuss two scenarios for the origin of J1023+1952; as a third, pre-existing dwarf galaxy involved in the interaction with NGC 3227 and NGC 3226, or a newly-forming dwarf galaxy condensing out of the tidal debris removed from the gaseous disk of NGC 3227. Given the lack of a detectable old stellar population, a tidal origin is more likely. If J1023+1952 is a bound object forming from returning gaseous tidal tail material, we infer a dynamically young age similar to its star-formation age, and suggests it is in the earliest stages of TDG evolution. Whatever the origin of J1023+1952 we suggest that its star formation is shock-triggered by collapsing tidal debris. (Abridged)

  18. Analysis of reactor material experiments investigating corium crust stability and heat transfer in jet impingement flow

    SciTech Connect (OSTI)

    Sienicki, J.J.; Spencer, B.W.

    1985-01-01T23:59:59.000Z

    Presented is an analysis of the results of the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten corium initially at 3080/sup 0/K was directed downward upon a stainless steel plate. The experiments are a continuation of a program of reactor material tests investigating LWR severe accident phenomena. Objective of the present analysis is to determine the existence or nonexistence of a corium crust during impingement from comparison of the measured heatup of the plate (as measured by thermocouples imbedded immediately beneath the steel surface) with model calculations assuming alternately the presence and absence of a stable crust during impingement.

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

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-15T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Chen, Erinna

    2013-01-01T23:59:59.000Z

    dominant contributor to the ocean energy dissipation (see §dominant contributor to the ocean energy dissipation (see §of interest, e.g. the ocean kinetic energy and tidal

  1. 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

    2006-01-01T23:59:59.000Z

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

  2. 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

    2006-01-01T23:59:59.000Z

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

  3. 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

    2015-01-01T23:59:59.000Z

    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.

  4. Under consideration for publication in J. Functional Programming 1 Noninterference through Flow Analysis

    E-Print Network [OSTI]

    Gay, Simon

    Analysis Kohei Honda Queen Mary, London Nobuko Yoshida Imperial College London Abstract This paper proposes Extensions (1): In ation and Branching 30 6.1 In ation 30 6.2 Branching and Selection 31 #12; 2 K. Honda (Berger et al. 01; Yoshida et al. 01; Yoshida et al. 02; Honda and Yoshida 02; Honda et al. 04), whose

  5. Analysis of a multiphase, porous-flow imbibition experiment in fractured volcanic tuff

    SciTech Connect (OSTI)

    Eaton, R.R.; Bixler, N.E.

    1986-12-31T23:59:59.000Z

    A sub-meter-scale imbibition experiment has been analyzed using a finite element, multiphase-flow code. In the experiment, an initially dry cylindrical core of fractured volcanic tuff was saturated by contacting the ends with pressurized water. Our model discretely accounts for three primary fractures that may be present in the core, as indicated by measurements of porosity and saturation. We show that vapor transport has a small (less than 5%) effect on the speed of the wetting front. By using experimental results to estimate apparent spatial variations in permeability along the core, good agreement with measured, transient, saturation data was achieved. The sensitivity of predicted transient wetting fronts to permeability data indicates a need for more extensive measurements. We conclude that it will be difficult to characterize an entire repository - where inhomogeneities due to variations in matrix and fracture properties are not well known - solely from the results of sub-meter-scale laboratory testing and deterministic modeling. 16 refs., 8 figs., 1 tab.

  6. Drying analysis of a multiphase, porous-flow experiment in fractured volcanic tuff

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.; Russo, A.J.

    1987-12-31T23:59:59.000Z

    A submeter-scale drying experiment has been analyzed using a finite element, multiphase-flow code. In the experiment, an initially wet cylindrical core of fractured volcanic tuff was dried by blowing dry nitrogen over the ends. Our model discretely accounts for three primary fractures that may be present in the core, as indicated by measurements of porosity and saturation. We show that vapor transport is unimportant in the interior of the core; the rate of drying is controlled by transport of liquid water to the ends of the core, where it can evaporate and escape into the dry environment outside. By using previous experimental results to estimate apparent spatial variations in permeability along the core, good agreement between measured and calculated drying rates was achieved. However, predicted saturation profiles were much smoother that those measured experimentally, presumably because of centimeter-scale inhomogeneities in the core sample. Our results indicate that water is transported chiefly as liquid from the interior to the edges of the core, where it evaporates and escapes out the ends. Thus, liquid-phase transport controls the overall drying rate. 18 refs., 8 figs., 1 tab.

  7. Tilted accretion discs in cataclysmic variables: tidal instabilities and superhumps

    E-Print Network [OSTI]

    J. R. Murray; P. J. Armitage

    1998-09-10T23:59:59.000Z

    We investigate the growth of tidal instabilities in accretion discs in a binary star potential, using three dimensional numerical simulations. As expected from analytic work, the disc is prone to an eccentric instability provided that it is large enough to extend to the 3:1 resonance. The eccentric disc leads to positive superhumps in the light curve. It has been proposed that negative superhumps might arise from a tilted disc, but we find no evidence that the companion gravitational tilt instability can grow fast enough in a fluid disc to create a measurable inclination. The origin of negative superhumps in the light curves of cataclysmic variables remains a puzzle.

  8. Pulse Tidal formerly Pulse Generation | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form History Facebook icon TwitterZip JumpProwindPuda Coal IncPulse Tidal

  9. 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOf KilaueaInformation Other4Q07)AK ProjectMS ProjectJerseyBW2 Tidal

  10. MHK Projects/Orient Point 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOf KilaueaInformationCygnet <|Galway Bay IE <Orcadian WaveTidal

  11. MHK Technologies/KESC Tidal Generator | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend < MHK ProjectsFlagship <HelixKESC Tidal Generator <

  12. MHK Technologies/TidalStar | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend < MHKconverter < MHKDUCK <TidalStar < MHK

  13. Tidal Stream Power Web GIS Tool | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolarTharaldson Ethanol LLCEnergyoThornwood,TianfuTidal Sails AS Jump

  14. Flow instabilities in the core and the coolant circuit of advances low-boiling light water reacto: classification of causes and development of simulator for the future analysis

    E-Print Network [OSTI]

    Rezvyi, Aleksey

    2002-01-01T23:59:59.000Z

    . . 1. 3. Analysis method determination. 2. THEORETICAL ASPECTS OF DIFFERENT TYPES OF THE THERMO-HYDRAULIC INSTABILITIES. . 2. 1. Static instability of loading charactenstic. . . . . . . . . . . . . . . . . . . . . . . 2. 2. Resonance instability... in the 1C L-BWR during heat-up process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diagram of components hierarchy of the Thermo-Hydraulic instabilities phenomenon. . The steam generating heating channels instability area, mass flow vs...

  15. 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

  16. 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

    2005-01-01T23:59:59.000Z

    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

  17. A Tidal Hydrology Assessment for Reconnecting Spring Branch Creek to Suisun Marsh, Solano County CA: Predicting the Impact to the Federally Listed Plant Soft Bird's Beak

    E-Print Network [OSTI]

    Olson, Jessica J.

    2011-01-01T23:59:59.000Z

    this study. Changes in hydrology are not the only potentialA Tidal Hydrology Assessment for Reconnecting Spring Branchmay change the tidal hydrology and impact the area occupied

  18. HAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET

    E-Print Network [OSTI]

    Dushaw, Brian

    precision to quantify the tidal power dissipated in the nearfield of the Ridge. The data are vitalHAWAIIAN OCEAN MIXING EXPERIMENT (HOME): FARFIELD PROGRAM HAWAIIAN TIDAL ENERGY BUDGET Principal and ocean acoustic tomography have brought a new dimension to the subject. We propose to measure the energy

  19. Continental Shelf Research 26 (2006) 13601374 Characterizing chaotic dispersion in a coastal tidal model

    E-Print Network [OSTI]

    LaCasce, Joseph H.

    2006-01-01T23:59:59.000Z

    Lyapunov exponents; Norwegian coast; Tidal currents 1. Introduction The coastal shelf is an important of Mathematics, University of Oslo, P.O. Box 1053, 0316 Blindern, Norway c Norwegian Meteorological Institute, P to study dispersion and mixing in a model in the Norwegian Trondheim fjord. We focus on the tidally driven

  20. NOAA Technical Memorandum OAR PMEL-122 Tidal Datum Distributions in Puget Sound,

    E-Print Network [OSTI]

    NOAA Technical Memorandum OAR PMEL-122 Tidal Datum Distributions in Puget Sound, Washington, Based . . . . . . . . . . . . . . 5 3. Puget Sound Channel Tide Model . . . . . . . . . . . . . . . 6 3.1 Description of the channel . . . . . . . . . . . . . . . . . . . . . . . . . 30 9. Appendix: Tidal harmonic constants in Puget Sound . . . 30 10. References

  1. Impact of sheep grazing on juvenile sea bass, Dicentrarchus labrax L., in tidal salt marshes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Impact of sheep grazing on juvenile sea bass, Dicentrarchus labrax L., in tidal salt marshes P L., from sheep grazed and ungrazed tidal salt marshes were com- pared qualitatively. Juvenile sea bass colonise the salt marsh at ¯ood during 43% of the spring tides which inundate the salt

  2. On the dynamics and morphology of extensive tidal mudflats: Integrating remote sensing data

    E-Print Network [OSTI]

    Ezer,Tal

    On the dynamics and morphology of extensive tidal mudflats: Integrating remote sensing data sensing data and inundation models allows the mapping of extensive tidal mudflats in a sub-Arctic estuary changes in mudflats morphology, and 3. mapping previously unobserved mud- flat topographies in order

  3. 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; 4558 Oceanography: Physical: Sediment transport; KEYWORDS: estuaries, intertidal mudflats, intertidal

  4. Dynamical resonance locking in tidally interacting binary systems

    E-Print Network [OSTI]

    Joshua Burkart; Eliot Quataert; Phil Arras

    2014-10-25T23:59:59.000Z

    We examine the dynamics of resonance locking in detached, tidally interacting binary systems. In a resonance lock, a given stellar or planetary mode is trapped in a highly resonant state for an extended period of time, during which the spin and orbital frequencies vary in concert to maintain the resonance. This phenomenon is qualitatively similar to resonance capture in planetary dynamics. We show that resonance locks can accelerate the course of tidal evolution in eccentric systems and also efficiently couple spin and orbital evolution in circular binaries. Previous analyses of resonance locking have not treated the mode amplitude as a fully dynamical variable, but rather assumed the adiabatic (i.e. Lorentzian) approximation valid only in the limit of relatively strong mode damping. We relax this approximation, analytically derive conditions under which the fixed point associated with resonance locking is stable, and further check these analytic results using numerical integrations of the coupled mode, spin, and orbital evolution equations. These show that resonance locking can sometimes take the form of complex limit cycles or even chaotic trajectories. We provide simple analytic formulae that define the binary and mode parameter regimes in which resonance locks of some kind occur (stable, limit cycle, or chaotic). We briefly discuss the astrophysical implications of our results for white dwarf and neutron star binaries as well as eccentric stellar binaries.

  5. Tidal deformation of a slowly rotating material body. I. External metric

    E-Print Network [OSTI]

    Landry, Philippe

    2015-01-01T23:59:59.000Z

    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 environment requires the introduction of four new quantities, which we designate as rotational-tidal Love numbers. All these Love numbers are gauge ...

  6. LOSS OF COOLANT ACCIDENT AND LOSS OF FLOW ACCIDENT ANALYSIS OF THE ARIES-AT DESIGN E. A. Mogahed, L. El-Guebaly, A. Abdou, P. Wilson, D. Henderson and the ARIES Team

    E-Print Network [OSTI]

    California at San Diego, University of

    LOSS OF COOLANT ACCIDENT AND LOSS OF FLOW ACCIDENT ANALYSIS OF THE ARIES-AT DESIGN E. A. Mogahed, L accident (LOCA) and loss of flow accident (LOFA) analysis is performed for ARIES-AT, an advanced fusion of steel in the reactor is about (600 °C - 700°C) after about 4 days from the onset of the accident

  7. 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.

    reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...

  8. 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.

    2013-02-28T23:59:59.000Z

    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.

  9. Tidal Residual Eddies and their Effect on Water Exchange in Puget Sound

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-30T23:59:59.000Z

    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.

  10. 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

    2009-08-02T23:59:59.000Z

    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.

  11. Field Measurements at River and Tidal Current Sites for Hydrokinetic Energy Development: Best Practices Manual

    SciTech Connect (OSTI)

    Neary, Vincent S [ORNL; Gunawan, Budi [Oak Ridge National Laboratory (ORNL)

    2011-09-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2011-10-01T23:59:59.000Z

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

  13. Analysis of reactor material experiments investigating oxide fuel crust stability and heat transfer in jet impingement flow

    SciTech Connect (OSTI)

    Sienicki, J.J.; Spencer, B.W.

    1985-01-01T23:59:59.000Z

    An analysis is presented of the crust stability and heat transfer behavior in the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten oxide fuel at approx. 160/sup 0/K above its freezing temperature was impinged normally upon stainless steel plates initially at 300 and 385 K. The major issue is the existence of nonexistence of a stable solidified layer of fuel, or crust, interstitial to the flowing hot fuel and the steel substrate, tending to insulate the steel from the hot molten fuel. A computer model was developed to predict the heatup of thermocouples imbedded immediately beneath the surface of the plate for both of the cases in which a stable crust is assumed to be either present or absent during the impingement phase. Comparison of the model calculations with the measured thermocouple temperatures indicates that a protective crust was present over nearly all of the plate surface area throughout the impingement process precluding major melting of the plate steel. However, the experiments also show evidence for very localized and isolated steel melting as revealed by localized and isolated pitting of the steel surface and the response of thermocouples located within the pitted region.

  14. annular vertical flow: Topics by E-print Network

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

    of the polymer solution only. The linear stability analysis of the flow in the short-wave approximation captures quantitatively the flow diagram. Surprisingly, unstable flows...

  15. Tidal Downsizing model. II. Planet-metallicity correlations

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01T23:59:59.000Z

    Core Accretion (CA), the de-facto accepted theory of planet formation, requires formation of massive solid cores as a prerequisite for assembly of gas giant planets. The observed metallicity correlations of exoplanets are puzzling in the context of CA. While gas giant planets are found preferentially around metal-rich host stars, planets smaller than Neptune orbit hosts with a wide range of metallicities. We propose an alternative interpretation of these observations in the framework of a recently developed planet formation hypothesis called Tidal Downsizing (TD). We perform population synthesis calculations based on TD, and find that the connection between the populations of the gas giant and the smaller solid-core dominated planets is non linear and not even monotonic. While gas giant planets formed in the simulations in the inner few AU region follow a strong positive correlation with the host star metallicity, the smaller planets do not. The simulated population of these smaller planets shows a shallow pe...

  16. SPH simulations of tidally unstable accretion disks in cataclysmic variables

    E-Print Network [OSTI]

    James R. Murray

    1995-11-08T23:59:59.000Z

    We numerically study the precessing disk model for superhump in the SU~UMa subclass of cataclysmic variables, using a two dimensional SPH code specifically designed for thin disk problems. Two disk simulations for a binary with mass ratio $q=\\frac{3}{17}$ (similar to OY~Car) are performed, in order to investigate the Lubow (1991 a,b) tidal resonance instability mechanism. In the first calculation, a disk evolves under steady mass transfer from $L_1$. In the second simulation, mass is added in Keplerian orbit to the inner disk. The two disks follow similar evolutionary paths. However the $L_1$ stream-disk interaction is found to slow the disk's radial expansion and to circularise gas orbits. The initial eccentricity growth in our simulations is exponential at a rate slightly less than predicted by Lubow (1991a). We do not observe a clearing of material from the resonance region via the disk's tidal response to the $m=2$ component of the binary potential as was described in Lubow (1992). Instead the $m=2$ response weakens as the disk eccentricty increases. Both disks reach an eccentric equilibrium state, in which they undergo prograde precession. The rate of viscous energy dissipation in the disks has a periodic excess with a period matching the disk's rotation. The source is identified as a large region in the outer disk, and the mechanism by which it is produced is identified. The time taken for the periodic excess to develop is consistent with the first appearance of superhumps in a superoutburst.

  17. Origin of Tidal Dissipation in Jupiter: II. the Value of Q

    E-Print Network [OSTI]

    Yanqin Wu

    2005-11-28T23:59:59.000Z

    The process of tidal dissipation inside Jupiter is not yet understood. Its tidal quality factor ($Q$) is inferred to lie between $10^5$ and $10^6$. We examine effects of inertial-modes on tidal dissipation in a neutrally bouyant, core-less, uniformly rotating planet. The rate of dissipation caused by resonantly excited inertial-modes depends on the following three parameters: how well they are coupled to the tidal potential, how strongly they are dissipated (by the turbulent viscosity), and how densely distributed they are in frequency. We find that as a function of tidal frequency, the $Q$ value exhibits large fluctuations, with its maximum value set by the group of inertial-modes that have a typical offset from an exact resonance of order their turbulent damping rates. In our model, inertial-modes shed their tidally acquired energy very close to the surface within a narrow latitudinal zone (the 'singularity belt'), and the tidal luminosity escapes freely out of the planet. Strength of coupling between the tidal potential and inertial-modes is sensitive to the presence of density discontinuities inside Jupiter. In the case of a discreet density jump (as may be caused by the transition between metallic and molecular hydrogen), we find a time-averaged $Q \\sim 10^7$. Even though it remains unclear whether tidal dissipation due to resonant inertial-modes is the correct answer to the problem, it is impressive that our simple treatment here already leads to three to five orders of magnitude stronger damping than that from the equilibrium tide. Moreover, our conclusions are not affected by the presence of a small solid core, a different prescription for the turbulent viscosity, or nonlinear mode coupling, but they depend critically on the static stability in the upper atmosphere of Jupiter.

  18. Tidal channel deposits in Upper Cretaceous of northern Kaiparowits Plateau, Utah

    SciTech Connect (OSTI)

    Sanchez, J.D.; McCabe, P.J.

    1988-02-01T23:59:59.000Z

    Seven coarsening-upward sequences have been recognized in the 300 to 400-m thick John Henry Member of the Straight Cliffs Formation. These sequences have abundant hummocky cross-stratification and are interpreted as having formed by the progradation of wave-dominated shorelines. A detailed study of these sequences showed that in many cases channel deposits are incised into upper shoreface deposits. These channels are up t 15 m deep. Mudclasts, Ostrea and Inoceramus fragments, and pebbles are present at the base of many channels. Some channel lag deposits also contain logs with Teredolites borings. Thin units of flaser, wavy and lenticular bedding may be present at any position within the channel deposits but are most common higher in the sequences. The channels are, however, infilled predominantly with trough cross-bedded, fine to medium-grained sandstones. Some cross-beds show multiple reactivation surfaces and the bimodal nature of the paleocurrents suggests that the cross-beds were deposited by tidal currents. The presence of tidal bundles with double mud drapes in a few cross-beds confirms the interpretation of the sandstones as tidal channel deposits. At least 22 tidal bundles are present in one tidal bundle sequence, suggesting a semi-diurnal tidal cycle. Although, there is convincing evidence of tides within the channel deposits, the shoreface deposits show little evidence of reworking by tidal currents. Possible beach or intertidal mudflat deposits have a maximum thickness of 1.5 m. The Kaiparowits region during the Upper Cretaceous probably experienced, therefore, a microtidal regime with significant tidal currents being restricted to tidal inlets or estuaries.

  19. Tidal channel deposits in Upper Cretaceous of northern Kaiparowits Plateau, Utah

    SciTech Connect (OSTI)

    Sanchez, J.D.; McCabe, P.J.

    1988-01-01T23:59:59.000Z

    Seven coarsening-upward sequences have been recognized in the 300 to 400-m thick John Henry Member of the Straight Cliffs Formation. These sequences have abundant hummocky cross-stratification and are interpreted as having formed by the progradation of wave-dominated shorelines. A detailed study of these sequences showed that in many cases channel deposits are incised into upper shoreface deposits. These channels are up to 15 m deep. Mudclasts, Ostrea and Inoceramus fragments, and pebbles are present at the base of many channels. Some channel lag deposits also contain logs with Teredolites borings. Thin units of flaser, wavy and lenticular bedding may be present at any position within the channel deposits but are most common higher in the sequences. The channels are, however, infilled predominantly with trough cross-bedded, fine to medium-grained sandstones. Some crossbeds show multiple reactivation surfaces and the bimodal nature of the paleocurrents suggests that the cross-beds were deposited by tidal currents. The presence of tidal bundles with double mud drapes in a few cross-beds confirms the interpretation of the sandstones as tidal channel deposits. At least 22 tidal bundles are present in one tidal bundle sequence, suggesting a semi-diurnal tidal cycle. Although there is convincing evidence of tides within the channel deposits, the shoreface deposits show little evidence of reworking by tidal currents. Possible beach or intertidal mudflat deposits have a maximum thickness of 1.5 m. The Kaiparowits region during the Upper Cretaceous probably experience, therefore, a microtidal regime with significant tidal currents being restricted to tidal inlets or estuaries.

  20. Modeling the Energy Output from an In-Stream Tidal Turbine Farm

    E-Print Network [OSTI]

    Ye Li; Barbara J. Lence; Sander M. Calisal

    Abstract—This paper is based on a recent paper presented in the 2007 IEEE SMC conference by the same authors [1], discussing an approach to predicting energy output from an instream tidal turbine farm. An in-stream tidal turbine is a device for harnessing energy from tidal currents in channels, and functions in a manner similar to a wind turbine. A group of such turbines distributed in a site is called an in-stream tidal turbine farm which is similar to a wind farm. Approaches to estimating energy output from wind farms cannot be fully transferred to study tidal farms, however, because of the complexities involved in modeling turbines underwater. In this paper, we intend to develop an approach for predicting energy output of an in-stream tidal turbine farm. The mathematical formulation and basic procedure for predicting power output of a stand-alone turbine 1 is presented, which includes several highly nonlinear terms. In order to facilitate the computation and utilize the formulation for predicting power output from a turbine farm, a simplified relationship between turbine distribution and turbine farm energy output is derived. A case study is then conducted by applying the numerical procedure to predict the energy output of the farms. Various scenarios are implemented according to the environmental conditions in Seymour Narrows, British Columbia, Canada. Additionally, energy cost results are presented as an extension. Index Terms—renewable energy, in-stream turbine, tidal current, tidal power, vertical axis turbine, farm system modeling, in-stream tidal turbine farm 1 A stand-alone turbine refers to a turbine around which there is no other turbine that might potentially affect the performance of this turbine.

  1. TIDAL DISSIPATION COMPARED TO SEISMIC DISSIPATION: IN SMALL BODIES, EARTHS, AND SUPER-EARTHS

    SciTech Connect (OSTI)

    Efroimsky, Michael, E-mail: michael.efroimsky@usno.navy.mil [U.S. Naval Observatory, Washington, DC 20392 (United States)

    2012-02-20T23:59:59.000Z

    While the seismic quality factor and phase lag are defined solely by the bulk properties of the mantle, their tidal counterparts are determined by both the bulk properties and the size effect (self-gravitation of a body as a whole). For a qualitative estimate, we model the body with a homogeneous sphere, and express the tidal phase lag through the lag in a sample of material. Although simplistic, our model is sufficient to understand that the lags are not identical. The difference emerges because self-gravitation pulls the tidal bulge down. At low frequencies, this reduces strain and the damping rate, making tidal damping less efficient in larger objects. At higher frequencies, competition between self-gravitation and rheology becomes more complex, though for sufficiently large super-Earths the same rule applies: the larger the planet, the weaker the tidal dissipation in it. Being negligible for small terrestrial planets and moons, the difference between the seismic and tidal lagging (and likewise between the seismic and tidal damping) becomes very considerable for large exoplanets (super-Earths). In those, it is much lower than what one might expect from using a seismic quality factor. The tidal damping rate deviates from the seismic damping rate, especially in the zero-frequency limit, and this difference takes place for bodies of any size. So the equal in magnitude but opposite in sign tidal torques, exerted on one another by the primary and the secondary, have their orbital averages going smoothly through zero as the secondary crosses the synchronous orbit. We describe the mantle rheology with the Andrade model, allowing it to lean toward the Maxwell model at the lowest frequencies. To implement this additional flexibility, we reformulate the Andrade model by endowing it with a free parameter {zeta} which is the ratio of the anelastic timescale to the viscoelastic Maxwell time of the mantle. Some uncertainty in this parameter's frequency dependence does not influence our principal conclusions.

  2. PVP-Vol.246/AMD-Vol. 143,New Methods in Transient Analysis COMPUTATION OF UNSTEADY INCOMPRESSIBLE FLOWS

    E-Print Network [OSTI]

    Mittal, Sanjay

    element computation of unsteady in- compressible flows, with emphasis on the space-time formulations, itSST approach the frequency of remeshing is minimized to minimize the projection errors involved in remeshing fluid-structure interaction prob- lems such as vortex-induced oscillations of a cylinder and flow past

  3. Design of a sediment quality assessment for the tidal Christina River Basin

    SciTech Connect (OSTI)

    Olinger, K.; Allen, R.; Williams, S. [Delaware State Dept. of Natural Resources and Environmental Control, Dover, DE (United States)

    1995-12-31T23:59:59.000Z

    A detailed baseline sediment study was designed and conducted within the tidal portion of the Christina River Basin, Delaware. A complementary battery of field-screening and laboratory analyses was established in order to obtain substantial coverage of the basin at reasonable cost. The approach provided for 180 sediment sample locations from a 15 mile stretch of the Christina River, the proximal reaches of its tributaries, and associated wetlands. Analytical parameters consisted of physiochemical measurements (TOC, grain size distribution, and redox potential), total metals, major anions, carcinogenic polynuclear aromatic hydrocarbons, polychlorinated biphenyls, pH, and metals partitioning analysis. Toxicity indicators included in the study were: SEM/AVS analysis, IQ{reg_sign} toxicity tests, Microtox{reg_sign}, and Hyalella azteca 10-day acute toxicity tests. This basin-wide approach successfully established a database of sediment information that allowed for the determination of: contaminants of concern; contaminant spatial distribution; potential ecological impacts; contaminant/indicator relationships; and potential upland contaminant source areas. The incorporation of low cost field and analytical methods permitted the use of short-spaced systematic sampling thus eliminating stratified random sampling methods and the need to focus on localized reaches. The database was sufficiently large to allow for statistically valid analyses of the results. Additionally, it will aid in the delineation of relevant strata for subsequent monitoring, provide a comparative baseline for future investigations, and guide state decision-making.

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

    E-Print Network [OSTI]

    Bryant, Duncan Burnette

    2011-08-08T23:59:59.000Z

    Akker 1999), and ocean CO2 sequestration (Adams and Wannamaker 2005; Adams and Wannamaker 2006). In particular, ocean CO2 sequestration has been noted by the Intergovernmental Panel on Climate Change in its 2005 special report on Carbon Dioxide... for direct carbon sequestration in the oceans have been considered as a means to mitigate the effects on global warming of burning fossil fuels. While the concept of CO2 sequestration is promising, the turbulent structures in multiphase plumes...

  5. Division of Water, Parts 660-661: Tidal Wetlands (New York)

    Broader source: Energy.gov [DOE]

    These regulations require permits for any activity which directly or indirectly may have a significant adverse effect on the existing condition of any tidal wetland, including but not limited to...

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

    E-Print Network [OSTI]

    North Carolina at Chapel Hill, University of

    overcome the tendency for tidal power to produce a well-mixed system". Additionally, they expressed some are explored using a potential energy formulation for the South Atlantic Bight (SAB). The efficiency of wind

  7. Analytical Model of Tidal Distortion and Dissipation for a Giant Planet with a Viscoelastic Core

    E-Print Network [OSTI]

    Storch, Natalia I

    2015-01-01T23:59:59.000Z

    We present analytical expressions for the tidal Love numbers of a giant planet with a solid core and a fluid envelope. We model the core as a uniform, incompressible, elastic solid, and the envelope as a non-viscous fluid satisfying the $n=1$ polytropic equation of state. We discuss how the Love numbers depend on the size, density, and shear modulus of the core. We then model the core as a viscoelastic Maxwell solid and compute the tidal dissipation rate in the planet as characterized by the imaginary part of the Love number $k_2$. Our results improve upon existing calculations based on planetary models with a solid core and a uniform ($n=0$) envelope. Our analytical expressions for the Love numbers can be applied to study tidal distortion and viscoelastic dissipation of giant planets with solid cores of various rheological properties, and our general method can be extended to study tidal distortion/dissipation of super-earths.

  8. The Distribution of Submersed Aquatic Vegetation in the Fresh and Oligohaline Tidal Potomac River, 2004

    E-Print Network [OSTI]

    Washington, DC to Broad Creek, MD, 2004...............................................................................6 2. Percent cover of hydrilla in SAV beds located in the tidal Potomac River from Broad Creek, MD to Chicamuxen Creek, MD, 2004.......................................................................7 3. Percent

  9. 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...

  10. Groundwater response to dual tidal fluctuations in a peninsula or an elongated island

    E-Print Network [OSTI]

    Zhan, Hongbin

    1 , Hongbin Zhan2,3, *, and Zhonghua Tang1 1 School of Environmental Studies, China University of the tidal fluctuations. This is called quasi-steady state condition *Correspondence to: Hongbin Zhan

  11. Integration of Wave and Tidal Power into the Haida Gwaii Electrical Grid

    E-Print Network [OSTI]

    Victoria, University of

    , Canada that relies heavily on diesel fuel for energy generation. An investigation is done into the potential for electricity generation using both tidal stream and wave energy in Haida Gwaii. A mixed integer

  12. Hydraulic properties of an artificial tidal inlet through a Texas barrier beach

    E-Print Network [OSTI]

    Prather, Stanley Harold

    1972-01-01T23:59:59.000Z

    HYDRAULIC PROPERTIES OF AN ARTIFICIAL TIDAL INLET THROUGH A TEXAS BARRIER BEACH A Thesis by STANLEY HAROLD PRATHER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1972 Major Sub]ect: Civil Engineering HYDRAULIC PROPERTIES OF AN ARTIFICIAL TIDAL INLET THROUGH A TEXAS BARRIER BEACH A Thesis by STANLEY HAROLD PRATHER Approved as to style and content by: (Chairman of Committee) (( (Head...

  13. Stability analysis of a phase-field model of gravity-driven unsaturated flow through porous media

    E-Print Network [OSTI]

    Cueto-Felgueroso, Luis

    The formation of preferential flow paths during infiltration of water into homogeneous, dry soil is an important phenomenon whose explanation and prediction have remained elusive under the standard theories of multiphase ...

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

    E-Print Network [OSTI]

    Haghshenas, Arash

    2013-04-24T23:59:59.000Z

    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 ...

  15. 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-

    2012-12-13T23:59:59.000Z

    Very High Temperature Rector (VHTR) had been designated as one of those promising reactors for the Next Generation (IV) Nuclear Plant (NGNP). For a prismatic core VHTR, one of the most crucial design considerations is the bypass flow and crossflow...

  16. Gravitational self-force corrections to two-body tidal interactions and the effective one-body formalism

    E-Print Network [OSTI]

    Donato Bini; Thibault Damour

    2014-09-24T23:59:59.000Z

    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.

  17. 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.

    2013-11-09T23:59:59.000Z

    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.

  18. 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

    2014-01-01T23:59:59.000Z

    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...

  19. On tidal capture of primordial black holes by neutron stars

    E-Print Network [OSTI]

    Guillaume Defillon; Etienne Granet; Petr Tinyakov; Michel H. G. Tytgat

    2014-09-01T23:59:59.000Z

    The fraction of primordial black holes (PBHs) of masses $10^{17} - 10^{26}$ g in the total amount of dark matter may be constrained by considering their capture by neutron stars (NSs), which leads to the rapid destruction of the latter. The constraints depend crucially on the capture rate which, in turn, is determined by the energy loss by a PBH passing through a NS. Two alternative approaches to estimate the energy loss have been used in the literature: the one based on the dynamical friction mechanism, and another on tidal deformations of the NS by the PBH. The second mechanism was claimed to be more efficient by several orders of magnitude due to the excitation of particular oscillation modes reminiscent of the surface waves. We address this disagreement by considering a simple analytically solvable model that consists of a flat incompressible fluid in an external gravitational field. In this model, we calculate the energy loss by a PBH traversing the fluid surface. We find that the excitation of modes with the propagation velocity smaller than that of PBH is suppressed, which implies that in a realistic situation of a supersonic PBH the large contributions from the surface waves are absent and the above two approaches lead to consistent expressions for the energy loss.

  20. Tidal Streams and Low Mass Companions of M31

    E-Print Network [OSTI]

    Robert Braun; David Thilker

    2003-12-04T23:59:59.000Z

    We have imaged the extended HI environment of M31 with an unprecedented combination of high resolution and sensitivity. We detect a number of distinct High Velocity Cloud components associated with M31. A sub-set of the features within 30 kpc appear to be tidal in origin. A filamentary ``halo'' component is concentrated at the M31 systemic velocity and appears to extend into a ``bridge'' connecting M31 and M33. This may represent condensation in coronal gas. A population of discrete clouds is detected out to radii of about 150 kpc. Discrete cloud line-widths are correlated with HI mass and are consistent with a 100:1 ratio of dark to HI mass. These may be the gaseous counterparts of low-mass dark-matter satellites. The combined distribution of M31's HVC components can be characterized by a spatial Gaussian of 55 kpc dispersion and yields an N_HI distribution function which agrees well with that of low red-shift QSOs.

  1. 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

    2010-01-01T23:59:59.000Z

    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...

  2. Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta, Lower Columbia River, 2007 Annual Report.

    SciTech Connect (OSTI)

    Sobocinski, Kathryn; Johnson, Gary; Sather, Nichole [Pacific Northwest National Laboratory

    2008-03-17T23:59:59.000Z

    This document is the first annual report for the study titled 'Ecology of Juvenile Salmonids in Shallow Tidal Freshwater Habitats in the Vicinity of the Sandy River Delta in the Lower Columbia River'. Hereafter, we refer to this research as the Tidal Freshwater Monitoring (TFM) Study. The study is part of the research, monitoring, and evaluation effort developed by the Action Agencies (Bonneville Power Administration, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation) in response to obligations arising from the Endangered Species Act as a result of operation of the Federal Columbia River Power System (FCRPS). The project is performed under the auspices of the Northwest Power and Conservation Council's Columbia Basin Fish and Wildlife Program. The goal of the 2007-2009 Tidal Freshwater Monitoring Study is to answer the following questions: In what types of habitats within the tidal freshwater area of the lower Columbia River and estuary (LCRE; Figure 1) are yearling and subyearling salmonids found, when are they present, and under what environmental conditions?1 And, what is the ecological importance2 of shallow (0-5 m) tidal freshwater habitats to the recovery of Upper Columbia River spring Chinook salmon and steelhead and Snake River fall Chinook salmon? Research in 2007 focused mainly on the first question, with fish stock identification data providing some indication of Chinook salmon presence at the variety of habitat types sampled. The objectives and sub-objectives for the 2007 study were as follows: (1) Habitat and Fish Community Characteristics-Provide basic data on habitat and fish community characteristics for yearling and subyearling salmonids at selected sites in the tidal freshwater reach in the vicinity of the Sandy River delta. (1a) Characterize vegetation assemblage percent cover, conventional water quality, substrate composition, and beach slope at each of six sampling sites in various tidal freshwater habitat types. (1b) Determine fish community characteristics, including species composition, abundance, and temporal and spatial distributions. (1c) Estimate the stock of origin for the yearling and subyearling Chinook salmon captured at the sampling sites using genetic analysis. (1d) Statistically assess the relationship between salmonid abundance and habitat parameters, including ancillary variables such as temperature and river stage. (2) Acoustic Telemetry Monitoring-Assess feasibility of applying Juvenile Salmon Acoustic Telemetry System (JSATS) technology to determine migration characteristics from upriver of Bonneville Dam through the study area (vicinity of the Sandy River delta/Washougal River confluence). (2a) Determine species composition, release locations, and distributions of JSATS-tagged fish. (2b) Estimate run timing, residence times, and migration pathways for these fish. Additionally, both objectives serve the purpose of baseline research for a potential tidal rechannelization project on the Sandy River. The U.S. Forest Service, in partnership with the Bonneville Power Administration and the U.S. Army Corps of Engineers, is currently pursuing reconnection of the east (relict) Sandy River channel with the current channel to improve fish and wildlife habitat in the Sandy River delta. Our study design and the location of sampling sites in this reach provide baseline data to evaluate the potential restoration.

  3. 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)

    2012-07-01T23:59:59.000Z

    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)

  4. 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

    2011-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Abdou, Mohamed

    2006-01-01T23:59:59.000Z

    . Zinkle, M. Youssef, Assessment of liquid breeder first wall and blanket options for the DEMO design, in channels. tural material. Helium cools the fist wall and blanket structure, and the self-cooled breeder, Pb in a poloidal channel of the DCLL blanket with a SiCf/SiC flow channel insert S. Smolentseva,, M. Abdoua, N

  6. Laboratory analysis of fluid flow and solute transport through a variably saturated fracture embedded in porous tuff

    SciTech Connect (OSTI)

    Chuang, Y.; Haldeman, W.R.; Rasmussen, T.C.; Evans, D.D. [Arizona Univ., Tucson, AZ (USA). Dept. of Hydrology and Water Resources

    1990-02-01T23:59:59.000Z

    Laboratory techniques are developed that allow concurrent measurement of unsaturated matrix hydraulic conductivity and fracture transmissivity of fractured rock blocks. Two Apache Leap tuff blocks with natural fractures were removed from near Superior, Arizona, shaped into rectangular prisms, and instrumented in the laboratory. Porous ceramic plates provided solution to block tops at regulated pressures. Infiltration tests were performed on both test blocks. Steady flow testing of the saturated first block provided estimates of matrix hydraulic conductivity and fracture transmissivity. Fifteen centimeters of suction applied to the second block top showed that fracture flow was minimal and matrix hydraulic conductivity was an order of magnitude less than the first block saturated matrix conductivity. Coated-wire ion-selective electrodes monitored aqueous chlorided breakthrough concentrations. Minute samples of tracer solution were collected with filter paper. The techniques worked well for studying transport behavior at near-saturated flow conditions and also appear to be promising for unsaturated conditions. Breakthrough curves in the fracture and matrix, and a concentration map of chloride concentrations within the fracture, suggest preferential flows paths in the fracture and substantial diffusion into the matrix. Average travel velocity, dispersion coefficient and longitudinal dispersivity in the fracture are obtained. 67 refs., 54 figs., 23 tabs.

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

    E-Print Network [OSTI]

    Sahoo, Dipankar

    2008-10-10T23:59:59.000Z

    staff members, Karen Knabe, Andrea Loggins, and Colleen Leatherman for their help with official paper work which saved me a lot of time. I extend my gratitude to all employees at the Oran W Nicks Low Speed Wind Tunnel for their valuable assistance... ..................................................... 31 4.1 Oran Nicks Low-Speed Wind Tunnel .................................................. 31 4.1.1 The DSF Inserts ..................................................................... 32 4.1.2 Tunnel Flow...

  8. Measurements of Turbulence at Two Tidal Energy Sites in Puget Sound, WA

    SciTech Connect (OSTI)

    Thomson, Jim; Polagye, Brian; Durgesh, Vibhav; Richmond, Marshall C.

    2012-06-05T23:59:59.000Z

    Field measurements of turbulence are pre- sented from two sites in Puget Sound, WA (USA) that are proposed for electrical power generation using tidal current turbines. Rapidly sampled data from multiple acoustic Doppler instruments are analyzed to obtain statistical mea- sures of fluctuations in both the magnitude and direction of the tidal currents. The resulting turbulence intensities (i.e., the turbulent velocity fluctuations normalized by the harmonic tidal currents) are typically 10% at the hub- heights (i.e., the relevant depth bin) of the proposed turbines. Length and time scales of the turbulence are also analyzed. Large-scale, anisotropic eddies dominate the energy spectra, which may be the result of proximity to headlands at each site. At small scales, an isotropic turbulent cascade is observed and used to estimate the dissipation rate of turbulent kinetic energy. Data quality and sampling parameters are discussed, with an emphasis on the removal of Doppler noise from turbulence statistics.

  9. 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.

    2014-01-01T23:59:59.000Z

    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

  10. Tidal hydraulics of San Luis Pass, Texas: a field and numerical investigation

    E-Print Network [OSTI]

    Morton, Scott Jerome

    1980-01-01T23:59:59.000Z

    TIDAL HYDPAULICS OF SAN LUIS PASS, TEXAS: A FIELD AND VBKRICAL INSTIGATION A Thesis by SCOTT JEROME MORTON Submitted to the Graduate College of Texas A(II University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE August 1980 i&Iajor Subject: Ocean Engineering TIDAL HyDRAULICS OF SAN LUIS PASS, TEXAS: A FIELD AND M&IERICAL INVESTIGATION A Thesis by SCOTI' JEROIIE MORTON Approved as to style and content by: (C?airman of Committee) (Member) /member...

  11. Macroscopic traversable wormholes with zero tidal forces inspired by noncommutative geometry

    E-Print Network [OSTI]

    Peter K. F. Kuhfittig

    2015-01-08T23:59:59.000Z

    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.

  12. TYBO/BENHAM: Model Analysis of Groundwater Flow and Radionuclide Migration from Underground Nuclear Tests in Southwestern Pahute Mesa, Nevada

    SciTech Connect (OSTI)

    Andrew Wolfsberg; Lee Glascoe; Guoping Lu; Alyssa; Olson; Peter Lichtner; Maureen McGraw; Terry Cherry; ,; Guy Roemer

    2002-09-01T23:59:59.000Z

    Recent field studies have led to the discovery of trace quantities of plutonium originating from the BENHAM underground nuclear test in two groundwater observation wells on Pahute Mesa at the Nevada Test Site. These observation wells are located 1.3 km from the BENHAM underground nuclear test and approximately 300 m from the TYBO underground nuclear test. In addition to plutonium, several other conservative (e.g. tritium) and reactive (e.g. cesium) radionuclides were found in both observation wells. The highest radionuclide concentrations were found in a well sampling a welded tuff aquifer more than 500m above the BENHAM emplacement depth. These measurements have prompted additional investigations to ascertain the mechanisms, processes, and conditions affecting subsurface radionuclide transport in Pahute Mesa groundwater. This report describes an integrated modeling approach used to simulate groundwater flow, radionuclide source release, and radionuclide transport near the BENHAM and TYBO underground nuclear tests on Pahute Mesa. The components of the model include a flow model at a scale large enough to encompass many wells for calibration, a source-term model capable of predicting radionuclide releases to aquifers following complex processes associated with nonisothermal flow and glass dissolution, and site-scale transport models that consider migration of solutes and colloids in fractured volcanic rock. Although multiple modeling components contribute to the methodology presented in this report, they are coupled and yield results consistent with laboratory and field observations. Additionally, sensitivity analyses are conducted to provide insight into the relative importance of uncertainty ranges in the transport parameters.

  13. 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

    2008-03-07T23:59:59.000Z

    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.

  14. China Camp's race against the tides: Predicting tidal marsh survival through comparison of project sea level rise elevations and sediment accretion rates

    E-Print Network [OSTI]

    Hannah, Whitney; Kuhn, Marlene

    2012-01-01T23:59:59.000Z

    2). The lowest zone, the mudflat, is primarily unvegetatedre-suspension of existing tidal mudflat sediment (Williams

  15. Flow injection analysis of phenolic compounds with carbon paste electrodes modified with tyrosinase purchased from different companies

    SciTech Connect (OSTI)

    Lindgren, A.; Emneus, J.; Csoeregi, E.; Gorton, L.; Marko-Varga, G. [Univ. of Lund (Sweden); Ruzgas, T. [Inst. of Biochemistry, Vilnius (Lithuania)

    1996-05-01T23:59:59.000Z

    Tyrosinase-modified carbon paste electrodes were prepared using lyophilised powder of the enzyme purchased from different companies. The selectivity of these electrodes for nine phenolic compounds, including six substituted catechols, has been studied. The signals obtained for catechol were always higher than those found for other phenolic compounds. Cyclic voltammetry and flow injection measurements indicated that the response of the tyrosinase-modified carbon paste electrodes was limited by the rate of the enzymatic oxidation of catechols. Different approaches of past electrode preparation have been studied and compared. Direct mixing of enzyme into the graphite powder doped with the osmium based mediator, resulted in the highest sensitivity for the studied substrates. However, substrate selectivity was found to be dependent on the source of enzyme used for electrode preparation.

  16. A CLASS OF ECCENTRIC BINARIES WITH DYNAMIC TIDAL DISTORTIONS DISCOVERED WITH KEPLER

    SciTech Connect (OSTI)

    Thompson, Susan E.; Barclay, Thomas; Howell, Steve B.; Still, Martin; Ibrahim, Khadeejah A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Everett, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Mullally, Fergal; Rowe, Jason; Christiansen, Jessie L.; Twicken, Joseph D.; Clarke, Bruce D. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Kurtz, Donald W.; Hambleton, Kelly, E-mail: susan.e.thompson@nasa.gov [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

    2012-07-01T23:59:59.000Z

    We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening or variability at timescales of 4-20 days, frequently accompanied by shorter period oscillations. We can explain the dominant features of the entire class with orbitally varying tidal forces that occur in close, eccentric binary systems. The large variety of light curve shapes arises from viewing systems at different angles. This hypothesis is supported by spectroscopic radial velocity measurements for five systems, each showing evidence of being in an eccentric binary system. Prior to the discovery of these 17 new systems, only four stars, where KOI-54 is the best example, were known to have evidence of these dynamic tides and tidally induced oscillations. We perform preliminary fits to the light curves and radial velocity data, present the overall properties of this class, and discuss the work required to accurately model these systems.

  17. Power Limitation Control for a PMSG-Based Marine Current Turbine at High Tidal Speed and

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Power Limitation Control for a PMSG-Based Marine Current Turbine at High Tidal Speed and Strong Sea the generator power at rated value. In this paper, two power limitation strategies with flux-weakening control by the power limitation and the rotor speed; this method enables to control the generator power at the limited

  18. Tidal Interactions and Disruptions of Giant Planets on Highly Eccentric Orbits

    E-Print Network [OSTI]

    Joshua A. Faber; Frederic A. Rasio; Bart Willems

    2004-11-15T23:59:59.000Z

    We calculate the evolution of planets undergoing a strong tidal encounter using smoothed particle hydrodynamics (SPH), for a range of periastron separations. We find that outside the Roche limit, the evolution of the planet is well-described by the standard model of linear, non-radial, adiabatic oscillations. If the planet passes within the Roche limit at periastron, however, mass can be stripped from it, but in no case do we find enough energy transferred to the planet to lead to complete disruption. In light of the three new extrasolar planets discovered with periods shorter than two days, we argue that the shortest-period cases observed in the period-mass relation may be explained by a model whereby planets undergo strong tidal encounters with stars, after either being scattered by dynamical interactions into highly eccentric orbits, or tidally captured from nearly parabolic orbits. Although this scenario does provide a natural explanation for the edge found for planets at twice the Roche limit, it does not explain how such planets will survive the inevitable expansion that results from energy injection during tidal circularization.

  19. The Distribution of Submersed Aquatic Vegetation in the Fresh and Oligohaline Tidal

    E-Print Network [OSTI]

    . Cover: Summer 2005 aerial photo of Dogue Creek and the Potomac River showing extensive dark areas to Dogue Creek, VA, 2005 ....................................................... 9 3. Percent cover of hydrilla in SAV beds located in the tidal Potomac River from Dogue Creek, VA to Quantico Creek, VA, 2005

  20. 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, California, USA Daniel B. Lluch-Cota Centro de Investigaciones Biologicas del Noroeste, La Paz, Mexico-period cooling are coincident with elevated levels of microbial pollution in the surf zone. This relationship can

  1. Multi-point tidal prediction using artificial neural network with tide-generating forces

    E-Print Network [OSTI]

    Multi-point tidal prediction using artificial neural network with tide-generating forces Hsien Available online 23 June 2006 Abstract This paper presents a neural network model of simulating tides Elsevier B.V. All rights reserved. Keywords: Neural networks; Tides; Tide-generating forces; Harmonic

  2. 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

  3. Dissolved oxygen stratification in two micro-tidal partially-mixed estuaries

    E-Print Network [OSTI]

    Mallin, Michael

    Dissolved oxygen stratification in two micro-tidal partially-mixed estuaries Jing Lin a,*, Lian Xie online 21 August 2006 Abstract The controlling physical factors for vertical oxygen stratification that vertical stratification of dissolved oxygen (DO) concentration can be explained by the extended Hansen

  4. Nitrogen Cycling and Ecosystem Exchanges in a Virginia Tidal Freshwater Marsh

    E-Print Network [OSTI]

    Neubauer, Scott C.

    loading due to watershed development and urbanization. We present a process-based mass balance model of N habitats for juvenile fishes, and buffering storm and flood waters (Odum et al. 1984; Mitsch and Gosselink dominated tidal freshwater marsh in the York River estuary, Virginia. The model, which was based

  5. Final Report for Sea-level Rise Response Modeling for San Francisco Bay Estuary Tidal

    E-Print Network [OSTI]

    Fleskes, Joe

    i Final Report for Sea-level Rise Response Modeling for San Francisco Bay Estuary Tidal Marshes Refuge in northern San Francisco Bay, California. #12;iii Final Report for Sea-level Rise Response)................................................................... 7 Sea-level rise scenario model inputs

  6. An analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer

    E-Print Network [OSTI]

    Jiao, Jiu Jimmy

    of China. 1. Introduction In most coastal areas, groundwater and seawater are in con- stant communicationAn analytical solution of groundwater response to tidal fluctuation in a leaky confined aquifer Jiu of the solution presented in this paper. This solution is based on a conceptual model under the assumption

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

    E-Print Network [OSTI]

    of mechanical energy for the ocean circulation and as such is 6 being incorporated changes in the ocean thermal structure, including 12 a ~1o C warming into state-of-the-art climate models. Calculation of the tidal energy flux depends on 7

  8. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Pedersen, Tom

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Dissertation Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines) #12;iii ABSTRACT This thesis examines methods for designing and analyzing kinetic turbines based

  9. Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines

    E-Print Network [OSTI]

    Victoria, University of

    Turbines by Michael Robert Shives B.Eng., Carleton University, 2008 A Thesis Submitted in Partial Hydrodynamic Modeling, Optimization and Performance Assessment for Ducted and Non-ducted Tidal Turbines examines methods for designing and analyzing kinetic turbines based on blade element momentum (BEM) theory

  10. Marine Tidal Current Electric Power Generation Technology: State of the Art and Current Status

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    resurgence in development of renewable ocean energy technology. Therefore, several demonstration projects appreciated as a vast renewable energy source. The energy is stored in oceans partly as thermal energy, partly categories: wave energy, marine and tidal current energy, ocean thermal energy, energy from salinity

  11. Acoustic Monitoring of Beluga Whale Interactions with Cook Inlet Tidal Energy Project

    SciTech Connect (OSTI)

    Worthington, Monty [Project Director - AK] [Project Director - AK

    2014-02-05T23:59:59.000Z

    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. Modeling of multiphase flow in permeable media: (1) Mathematical model; (2) Analysis of imbibition and drying experiments

    SciTech Connect (OSTI)

    Bixler, N.E.; Eaton, R.R.

    1986-12-31T23:59:59.000Z

    Calculating multiphase flow of water through fractured porous media, such as volcanic tuff, is a numerically challenging problem because of the highly nonlinear material characteristics of permeability and saturation which describe liquid and gas transport. Typically, the permeability of the fractured host rock being investigated for an underground nuclear waste repository at Yucca Mountain, Nevada increases by 15 orders of magnitude as the rock becomes saturated. Furthermore, permeability may vary by five orders of magnitude between geologic strata. Other nonlinear mechanisms - Knudsen diffusion, binary diffusion, vapor pressure lowering, and adsorption of vapor onto pore walls - may also strongly affect liquid and gas transport. In Part I of the presentation, the mathematical model and its computer implementation are presented. The application of these equations and solution procedures to problems related to underground waste repositories are addressed in Part II. Predicted results will be compared with the results of laboratory experiments in which a core of volcanic tuff has first undergone controlled imbibition, then drying. The importance of the various transport mechanisms is demonstrated by examining the predicted results. 14 figs.

  13. Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound

    SciTech Connect (OSTI)

    Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

    2012-03-30T23:59:59.000Z

    Hydrokinetic turbines will be a source of noise in the marine environment - both during operation and during installation/removal. High intensity sound can cause injury or behavioral changes in marine mammals and may also affect fish and invertebrates. These noise effects are, however, highly dependent on the individual marine animals; the intensity, frequency, and duration of the sound; and context in which the sound is received. In other words, production of sound is a necessary, but not sufficient, condition for an environmental impact. At a workshop on the environmental effects of tidal energy development, experts identified sound produced by turbines as an area of potentially significant impact, but also high uncertainty. The overall objectives of this project are to improve our understanding of the potential acoustic effects of tidal turbines by: (1) Characterizing sources of existing underwater noise; (2) Assessing the effectiveness of monitoring technologies to characterize underwater noise and marine mammal responsiveness to noise; (3) Evaluating the sound profile of an operating tidal turbine; and (4) Studying the effect of turbine sound on surrogate species in a laboratory environment. This study focuses on a specific case study for tidal energy development in Admiralty Inlet, Puget Sound, Washington (USA), but the methodologies and results are applicable to other turbine technologies and geographic locations. The project succeeded in achieving the above objectives and, in doing so, substantially contributed to the body of knowledge around the acoustic effects of tidal energy development in several ways: (1) Through collection of data from Admiralty Inlet, established the sources of sound generated by strong currents (mobilizations of sediment and gravel) and determined that low-frequency sound recorded during periods of strong currents is non-propagating pseudo-sound. This helped to advance the debate within the marine and hydrokinetics acoustic community as to whether strong currents produce propagating sound. (2) Analyzed data collected from a tidal turbine operating at the European Marine Energy Center to develop a profile of turbine sound and developed a framework to evaluate the acoustic effects of deploying similar devices in other locations. This framework has been applied to Public Utility District No. 1 of Snohomish Country's demonstration project in Admiralty Inlet to inform postinstallation acoustic and marine mammal monitoring plans. (3) Demonstrated passive acoustic techniques to characterize the ambient noise environment at tidal energy sites (fixed, long-term observations recommended) and characterize the sound from anthropogenic sources (drifting, short-term observations recommended). (4) Demonstrated the utility and limitations of instrumentation, including bottom mounted instrumentation packages, infrared cameras, and vessel monitoring systems. In doing so, also demonstrated how this type of comprehensive information is needed to interpret observations from each instrument (e.g., hydrophone data can be combined with vessel tracking data to evaluate the contribution of vessel sound to ambient noise). (5) Conducted a study that suggests harbor porpoise in Admiralty Inlet may be habituated to high levels of ambient noise due to omnipresent vessel traffic. The inability to detect behavioral changes associated with a high intensity source of opportunity (passenger ferry) has informed the approach for post-installation marine mammal monitoring. (6) Conducted laboratory exposure experiments of juvenile Chinook salmon and showed that exposure to a worse than worst case acoustic dose of turbine sound does not result in changes to hearing thresholds or biologically significant tissue damage. Collectively, this means that Chinook salmon may be at a relatively low risk of injury from sound produced by tidal turbines located in or near their migration path. In achieving these accomplishments, the project has significantly advanced the District's goals of developing a demonstration-scale tidal energy proj

  14. Flow chamber

    DOE Patents [OSTI]

    Morozov, Victor (Manassas, VA)

    2011-01-18T23:59:59.000Z

    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.

  15. Geological flows

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2008-11-19T23:59:59.000Z

    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. TRAC-PF1/MOD-1 analysis of Loss-Of-Flow Test L9-4

    SciTech Connect (OSTI)

    Meier, J.

    1985-01-01T23:59:59.000Z

    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.

  17. The effects of cold water injection and two-phase flow on skin factor and permeability estimates from pressure falloff analysis

    E-Print Network [OSTI]

    Linge, Frode

    1984-01-01T23:59:59.000Z

    33 54 78 LIST OF TABLES Tabl e Data for Bottomhole Temperature Calculation Reservoir and Thermal Properties for Model Verification Page 34 35 Water and Oil Viscosities for Model Verification . . 36 10 12 13 14 15 Water and Oil... Relative Permeabilities for Model Verification Data for Single-Phase Flow Runs Low Oil Viscosity for Single-Phase Flow Runs High Oil Viscosity for Single-Phase Flow Runs Data for Two-Phase Flow Runs Sumaary of Numerical Simulation Runs Results...

  18. Application of direct-fitting, mass-integral, and multi-ratemethods to analysis of flowing fluid electric conductivity logs fromHoronobe, Japan

    SciTech Connect (OSTI)

    Doughty, C.; Tsang, C.-F.; Hatanaka, K.; Yabuuchi, S.; Kurikami, H.

    2007-08-01T23:59:59.000Z

    The flowing fluid electric conductivity (FFEC) loggingmethod is an efficient way to provide information on the depths,salinities, and transmissivities of individual conductive featuresintercepted by a borehole, without the use of specialized probes. Usingit in a multiple-flow-rate mode allows, in addition, an estimate of theinherent "far-field" pressure heads in each of the conductive features.The multi-rate method was successfully applied to a 500-m borehole in agranitic formation and reported recently. The present paper presents theapplication of the method to two zones within a 1000-m borehole insedimentary rock, which produced, for each zone, three sets of logs atdifferent pumping rates, each set measured over a period of about oneday. The data sets involve a number of complications, such as variablewell diameter, free water table decline in the well, and effects ofdrilling mud. To analyze data from this borehole, we apply varioustechniques that have been developed for analyzing FFEC logs:direct-fitting, mass-integral, and the multi-rate method mentioned above.In spite of complications associated with the tests, analysis of the datais able to identify 44 hydraulically conducting fractures distributedover the depth interval 150-775 meters below ground surface. Thesalinities (in FEC), and transmissivities and pressure heads (indimensionless form) of these 44 features are obtained and found to varysignificantly among one another. These results are compared with datafrom eight packer tests with packer intervals of 10-80 m, which wereconducted in this borehole over the same depth interval. They are foundto be consistent with these independent packer-test data, thusdemonstrating the robustness of the FFEC logging method under non-idealconditions.

  19. Three-dimensional analysis of future groundwater flow conditions and contaminant plume transport in the Hanford Site unconfined aquifer system: FY 1996 and 1997 status report

    SciTech Connect (OSTI)

    Cole, C.R.; Wurstner, S.K.; Williams, M.D.; Thorne, P.D.; Bergeron, M.P.

    1997-12-01T23:59:59.000Z

    A three-dimensional numerical model of groundwater flow and transport, based on the Coupled Fluid Energy, and Solute Transport (CFEST) code, was developed for the Hanford Site to support the Hanford Groundwater Project (HGWP), managed by Pacific Northwest National Laboratory. The model was developed to increase the understanding and better forecast the migration of several contaminant plumes being monitored by the HGWP, and to support the Hanford Site Composite Analysis for low-level waste disposal in the 200-Area Plateau. Recent modeling efforts have focused on continued refinement of an initial version of the three-dimensional model developed in 1995 and its application to simulate future transport of selected contaminant plumes in the aquifer system. This version of the model was updated using a more current version of the CFEST code called CFEST96. Prior to conducting simulations of contaminant transport with the three-dimensional model, a previous steady-state, two-dimensional model of the unconfined aquifer system was recalibrated to 1979 water-table conditions with a statistical inverse method implemented in the CFEST-INV computer code. The results of the recalibration were used to refine the three-dimensional conceptual model and to calibrate it with a conceptualization that preserves the two-dimensional hydraulic properties and knowledge of the aquifer`s three-dimensional properties for the same 1979 water-table conditions. The transient behavior of the three-dimensional flow model was also calibrated by adjusting model storage properties (specific yield) until transient water-table predictions approximated observed water-table elevations between 1979 and 1996.

  20. Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM

    E-Print Network [OSTI]

    Wray, Craig

    2010-01-01T23:59:59.000Z

    Type of Analysis CrossFlow; ! - Heat ExchangerType of Analysis CrossFlow; ! - Heat Exchanger ConfigurationType of Analysis CrossFlow; ! - Heat Exchanger Configuration

  1. Existence of new nonlocal field theory on noncommutative space and spiral flow in renormalization group analysis of matrix models

    E-Print Network [OSTI]

    Kawamoto, Shoichi

    2015-01-01T23:59:59.000Z

    In the previous study, we formulate a matrix model renormalization group based on the fuzzy spherical harmonics with which a notion of high/low energy can be attributed to matrix elements, and show that it exhibits locality and various similarity to the usual Wilsonian renormalization group of quantum field theory. In this work, we continue the renormalization group analysis of a matrix model with emphasis on nonlocal interactions where the fields on antipodal points are coupled. They are indeed generated in the renormalization group procedure and are tightly related to the noncommutative nature of the geometry. We aim at formulating renormalization group equations including such nonlocal interactions and finding existence of nontrivial field theory with antipodal interactions on the fuzzy sphere. We find several nontrivial fixed points and calculate the scaling dimensions associated with them. We also consider the noncommutative plane limit and then no consistent fixed point is found. This contrast between t...

  2. Changes in Beachface Bed Elevation over a Tidal Cycle on Santa Rosa Island, Florida and Matagorda, Texas

    E-Print Network [OSTI]

    Barrett, Gemma

    2009-06-09T23:59:59.000Z

    . Data from one ultrasonic sensor was chosen to compile for the tidal cycle. Sonic 4 was chosen because it was located midway through the swash zone and positioned on station 4 of the 8 transect stations which showed the best data for rising, high tide... CHANGES IN BEACHFACE BED ELEVATION OVER A TIDAL CYCLE ON SANTA ROSA ISLAND, FLORIDA AND MATAGORDA PENINSULA, TEXAS Major: Environmental Geosciences April 2009 Submitted to the Office of Undergraduate Research Texas A...

  3. 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

    2014-01-01T23:59:59.000Z

    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

  4. Non-linear evolution of the angular momentum of protostructures from tidal torques

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1996-04-15T23:59:59.000Z

    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.

  5. Spin alignments within the cosmic web: a theory of constrained tidal torques near filaments

    E-Print Network [OSTI]

    Codis, Sandrine; Pogosyan, Dmitry

    2015-01-01T23:59:59.000Z

    The geometry of the cosmic web drives in part the spin acquisition of galaxies. This can be explained in a Lagrangian framework, by identifying the specific long-wavelength correlations within the primordial Gaussian random field which are relevant to spin acquisition. Tidal Torque Theory is revisited in the context of such anisotropic environments, biased by the presence of a filament within a wall. The point process of filament-type saddles represents it most efficiently. The constrained misalignment between the tidal and the inertia tensors in the vicinity of filament-type saddles simply explains the distribution of spin directions. This misalignment implies in particular an azimuthal orientation for the spins of more massive galaxies and a spin alignment with the filament for less massive galaxies. This prediction is found to be in qualitative agreement with measurements in Gaussian random fields and N-body simulations. It relates the transition mass to the geometry of the saddle, and accordingly predicts...

  6. Broadband Acoustic Environment at a Tidal Energy Site in Puget Sound

    SciTech Connect (OSTI)

    Xu, Jinshan; Deng, Zhiqun; Martinez, Jayson J.; Carlson, Thomas J.; Myers, Joshua R.; Weiland, Mark A.

    2012-04-04T23:59:59.000Z

    Admiralty Inlet has been selected as a potential tidal energy site. It is located near shipping lanes, is a highly variable acoustic environment, and is frequented by the endangered southern resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines. Several monitoring technologies are being considered to determine the presence of SRKW near the turbines. Broadband noise level measurements are critical for determining design and operational specifications of these technologies. Acoustic environment data at the proposed site was acquired at different depths using a cabled vertical line array from three different cruises during high tidal period in February, May, and June 2011. The ambient noise level decreases approximately 25 dB re 1 ?Pa per octave from frequency ranges of 1 kHz to 70 kHz, and increases approximately 20 dB re 1 ?Pa per octave for the frequency from 70 kHz to 200 kHz. The difference of noise pressure levels in different months varies from 10 to 30 dB re 1 ?Pa for the frequency range below 70 kHz. Commercial shipping and ferry vessel traffic were found to be the most significant contributors to sound pressure levels for the frequency range from 100 Hz to 70 kHz, and the variation could be as high as 30 dB re 1 ?Pa. These noise level measurements provide the basic information for designing and evaluating both active and passive monitoring systems proposed for deploying and operating for tidal power generation alert system.

  7. EVOLUTION OF PLANETARY ORBITS WITH STELLAR MASS LOSS AND TIDAL DISSIPATION

    SciTech Connect (OSTI)

    Adams, Fred C. [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)] [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States); Bloch, Anthony M. [Math Department, University of Michigan, Ann Arbor, MI 48109 (United States)] [Math Department, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-11-10T23:59:59.000Z

    Intermediate mass stars and stellar remnants often host planets, and these dynamical systems evolve because of mass loss and tides. This paper considers the combined action of stellar mass loss and tidal dissipation on planetary orbits in order to determine the conditions required for planetary survival. Stellar mass loss is included using a so-called Jeans model, described by a dimensionless mass loss rate ? and an index ?. We use an analogous prescription to model tidal effects, described here by a dimensionless dissipation rate ? and two indices (q, p). The initial conditions are determined by the starting value of angular momentum parameter ?{sub 0} (equivalently, the initial eccentricity) and the phase ? of the orbit. Within the context of this model, we derive an analytic formula for the critical dissipation rate ?, which marks the boundary between orbits that spiral outward due to stellar mass loss and those that spiral inward due to tidal dissipation. This analytic result ? = ?(?, ?, q, p, ?{sub 0}, ?) is essentially exact for initially circular orbits and holds to within an accuracy of ?50% over the entire multi-dimensional parameter space, where the individual parameters vary by several orders of magnitude. For stars that experience mass loss, the stellar radius often displays quasi-periodic variations, which produce corresponding variations in tidal forcing; we generalize the calculation to include such pulsations using a semi-analytic treatment that holds to the same accuracy as the non-pulsating case. These results can be used in many applications, e.g., to predict/constrain properties of planetary systems orbiting white dwarfs.

  8. Mechanical design of flow batteries

    E-Print Network [OSTI]

    Hopkins, Brandon J. (Brandon James)

    2013-01-01T23:59:59.000Z

    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 ...

  9. Tidal inlet processes and deposits along a low energy coastline: easter Barataria Bight, Louisiana

    SciTech Connect (OSTI)

    Moslow, T.F.; Levin, D.R.

    1985-01-01T23:59:59.000Z

    Historical, seismic and vibracore data were used to determine the geologic framework of sand deposits along the predominantly muddy coastline of eastern Barataria Bight, Louisiana. Three inlet types with distinct sand body geometries and morphologies were identified and are found 1) at flanking barrier island systems spread laterally across the front of interdistributary bays; 2) in old distributary channels; 3) at overwash breaches; or 4) combination of these. Barataria Bight, a sheltered barrier island shoreline embayment with limited sand supply, minimal tidal range (36 cm) and low wave energies (30 cm) can be used to show examples of each inlet type. Barataria Pass and Quatre Bayou Pass are inlets located in old distributary channels. However, Barataria Pass has also been affected by construction between barrier islands. Pass Ronquille is located where the coastline has transgressed a low area in the delta plain. This breach is situated in a hydraulically efficient avenue between the Gulf and Bay Long behind it. Pass Abel is a combination of a low-profile barrier breach and the reoccupation of an old distributary channel. Shelf and shoreline sands are reworked from abandoned deltaic distributaries and headlands. Inner shelf sands are concentrated in thick (10 m) shore-normal relict distributary channels with fine grained cross-bedded and ripple laminated sand overlain by burrowed shelf muds. Shoreface sand deposits occur as 2-3 m thick, fine-grained, coarsening upward and burrowed ebb-tidal delta sequences and shore-parallel relict tidal inlet channels filled through lateral accretion.

  10. Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism

    E-Print Network [OSTI]

    M. Nagasawa; S. Ida; T. Bessho

    2008-01-09T23:59:59.000Z

    We have investigated the formation of close-in extrasolar giant planets through a coupling effect of mutual scattering, Kozai mechanism, and tidal circularization, by orbital integrations. We have carried out orbital integrations of three planets with Jupiter-mass, directly including the effect of tidal circularization. We have found that in about 30% runs close-in planets are formed, which is much higher than suggested by previous studies. We have found that Kozai mechanism by outer planets is responsible for the formation of close-in planets. During the three-planet orbital crossing, the Kozai excitation is repeated and the eccentricity is often increased secularly to values close enough to unity for tidal circularization to transform the inner planet to a close-in planet. Since a moderate eccentricity can remain for the close-in planet, this mechanism may account for the observed close-in planets with moderate eccentricities and without nearby secondary planets. Since these planets also remain a broad range of orbital inclinations (even retrograde ones), the contribution of this process would be clarified by more observations of Rossiter-McLaughlin effects for transiting planets.

  11. Lagoon and tidal flat sedimentation of the Upper Devonian Nisku Formation in southern Alberta

    SciTech Connect (OSTI)

    Slingsby, A. (Norcen Energy Resources Ltd., Calgary, Alberta (Canada)); Kissling, D.L. (Jackalope Geological Ltd., Lafayette, CO (United States))

    1991-06-01T23:59:59.000Z

    Since 1985, 26 oil pools containing 64 million bbl of oil in place have been discovered in the Nisku Formation in southern Alberta. The thoroughly dolomitized Nisku Formation varies from 20 to 30 m thick in southern Alberta and northern Montana. It overlies anhydrites and shaly carbonates of the Southesk or Duperow formations and underlies anhydrites of the Stettler or Potlatch formation. Burrowed, nodular-bedded skeletal wackestone, deposited over a shallow marine shelf, forms the basal Nisku Formation. These strata are succedded diachronously and unconformably by several tidal-flat and lagoon facies that include (1) southeast-thinning washover fans of cross-bedded peloidal grainstone; (2) laminated mudstone to current-bedded peloidal and intraclastic grainstone sourced within the lagoon; (3) stromatolitic mudstones; (4) laminated anhydrite beds precipitated during salina episodes; (5) Amphipora and brachiopod wackestones and thrombolites containing Renalcis, serpulids, and ostracoes, marking a brief marine invasion; and (6) brackish or freshwater shale and mudstone containing fragmented lycopod leaves and antiarch fish remains. These sediments are overlain by cross-bedded, peloidal, and calcisiltite grainstone and stromatolitic mudstone deposited in tidal channels and over shoals. All facies have been subjected to periodic subareal exposure which has produced leaching, solution collapse brecciation, teepee structures, and nodular-mosaic and void-filling anhydrite. Permeable reservoirs exist where leached, dolomitized tidal flat and lagoon sediments contain intercrystalline and pelmoldic porosity and little anhydrite cement.

  12. Origin of Tidal Dissipation in Jupiter: I. Properties of Inertial-Mode

    E-Print Network [OSTI]

    Yanqin Wu

    2005-11-28T23:59:59.000Z

    We study global inertial-modes with the purpose of unraveling the role they play in the tidal dissipation process of Jupiter. For spheres of uniformly rotating, neutrally buoyant fluid, we show that the partial differential equation governing inertial-modes can be separated into two ordinary differential equations when the density is constant, or when the density has a power-law dependence on radius. For more general density dependencies, we show that one can obtain an approximate solution to the inertial-modes that is accurate to the second order in wave-vector. Frequencies of inertial-modes are limited to $\\omega < 2 \\Omega$ ($\\Omega$ is the rotation rate), with modes propagating closer to the rotation axis having higher frequencies. An inertial-mode propagates throughout much of the sphere with a relatively constant wavelength, and a wave amplitude that scales with density as $1/\\sqrt{\\rho}$. It is reflected near the surface at a depth that depends on latitude, with the depth being much shallower near the special latitudes $\\theta = \\cos^{-1} \\pm \\omega/2\\Omega$. Around this region, this mode has the highest wave amplitude as well as the sharpest spatial gradient (the ``singularity belt''), thereby incurring the strongest turbulent dissipation. Inertial-modes naturally cause small Eulerian density perturbations, so they are only weakly coupled to the tidal potential. In a companion paper, we attempt to apply these results to the problem of tidal dissipation in Jupiter.

  13. Tidal salt marshes of the southeast Atlantic Coast: A community profile

    SciTech Connect (OSTI)

    Wiegert, R.G.; Freeman, B.J.

    1990-09-01T23:59:59.000Z

    This report is part of a series of community profiles on the ecology of wetland and marine communities. This particular profile considers tidal marshes of the southeastern Atlantic coast, from North Carolina south to northern Florida. Alone among the earth's ecosystems, coastal communities are subjected to a bidirectional flooding sometimes occurring twice each day; this flooding affects successional development, species composition, stability, and productivity. In the tidally influenced salt marsh, salinity ranges from less than 1 ppt to that of seawater. Dominant plant species include cordgrasses (Spartina alterniflora and S. cynosuroides), black needlerush (Juncus romerianus), and salt marsh bulrush (Scirpus robustus). Both terrestrail and aquatic animals occur in salt marshes and include herons, egrets ospreys (Pandion haliaetus), bald eagles (Haliaeetus leucocephalus), alligators (Alligator Mississippiensis), manatees (Trichecus manatus), oysters, mussels, and fiddler crabs. Currently, the only significant direct commercial use of the tidal salt marshes is by crabbers seeking the blue crab Callinectes sapidus, but the marshes are quite important recreationally, aesthetically, and educationally. 151 refs., 45 figs., 6 tabs.

  14. Tidally dominated depositional environment for the Mt. Simon Sandstone in central Illinois

    SciTech Connect (OSTI)

    Sargent, M.L.; Lasemi, Z. (Illinois State Geological Survey, Champaign, IL (United States))

    1993-03-01T23:59:59.000Z

    Several hundred feet of core from the upper part of the Mt. Simon in central Illinois have been examined macroscopically. Grain sizes and their systematics, bedding characteristics, sedimentary structures, and relationships among beds show that the upper Mt. Simon Sandstone is composed of a series of fining-upward cycles up to 10 m (30 feet) thick. A typical cycle consists, in ascending order, of a sandy subtidal facies, a mixed sand and mud intertidal-flat facies, and a muddy upper tidal-flat facies upward through the succession, the maximum and average grain size becomes progressively finer and the cycles thinner. The lower sandstone of each cycle contains beds that are massive to cross bedded and cross laminated; some beds show scoured reactivation surfaces. A few cycles contain a middle unit characterized by flaser and lenticular bedding and abundant mudcracks. Mudcracks also are common in the shale beds at the top of each cycle. Sedimentary structures such as reactivation surfaces, flaser and lenticular bedding, and mudcracks suggest that these cycles were deposited in peritidal environments. The presence of Skolithos in some cycles suggests very shallow marine conditions. The within-cycle upward fining is caused by regression or progradation that reflects a progressive decrease in current velocity from subtidal to intertidal parts of the tidal flat. Frequent flooding of the tidal flat resulted in repeated fining-upward cycles within the upper part of the Mt. Simon Sandstone.

  15. Ages of Star Clusters in the Tidal Tails of Merging Galaxies

    E-Print Network [OSTI]

    Mulia, A J; Whitmore, B C

    2015-01-01T23:59:59.000Z

    We study the stellar content in the tidal tails of three nearby merging galaxies, NGC 520, NGC 2623, and NGC 3256, using BVI imaging taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. The tidal tails in all three systems contain compact and fairly massive young star clusters, embedded in a sea of diffuse, unresolved stellar light. We compare the measured colors and luminosities with predictions from population synthesis models to estimate cluster ages and find that clusters began forming in tidal tails during or shortly after the formation of the tails themselves. We find a lack of very young clusters ($\\le 10$ Myr old), implying that eventually star formation shuts off in the tails as the gas is used up or dispersed. There are a few clusters in each tail with estimated ages that are older than the modeled tails themselves, suggesting that these may have been stripped out from the original galaxy disks. The luminosity function of the tail clusters can be described by a single powe...

  16. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source Reactor at Oak Ridge National Laboratory

    SciTech Connect (OSTI)

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

    1995-09-01T23:59:59.000Z

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effects of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

  17. Cooling Flows or Heating Flows?

    E-Print Network [OSTI]

    James Binney

    2003-10-08T23:59:59.000Z

    It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.

  18. Behavior of an heterogeneous annular FBR core during an unprotected loss of flow accident: Analysis of the primary phase with SAS-SFR

    SciTech Connect (OSTI)

    Massara, S.; Schmitt, D.; Bretault, A.; Lemasson, D.; Darmet, G.; Verwaerde, D. [EDF R and D, 1, Avenue du General de Gaulle, 92141 Clamart (France); Struwe, D.; Pfrang, W.; Ponomarev, A. [Karlsruher Institut fuer Technologie KIT, Institut fuer Neutronenphysik und Reaktortechnik INR, Hermann-von-Helmholtz-Platz 1, Gebaude 521, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-07-01T23:59:59.000Z

    In the framework of a substantial improvement on FBR core safety connected to the development of a new Gen IV reactor type, heterogeneous core with innovative features are being carefully analyzed in France since 2009. At EDF R and D, the main goal is to understand whether a strong reduction of the Na-void worth - possibly attempting a negative value - allows a significant improvement of the core behavior during an unprotected loss of flow accident. Also, the physical behavior of such a core is of interest, before and beyond the (possible) onset of Na boiling. Hence, a cutting-edge heterogeneous design, featuring an annular shape, a Na-plena with a B{sub 4}C plate and a stepwise modulation of fissile core heights, was developed at EDF by means of the SDDS methodology, with a total Na-void worth of -1 $. The behavior of such a core during the primary phase of a severe accident, initiated by an unprotected loss of flow, is analyzed by means of the SAS-SFR code. This study is carried-out at KIT and EDF, in the framework of a scientific collaboration on innovative FBR severe accident analyses. The results show that the reduction of the Na-void worth is very effective, but is not sufficient alone to avoid Na-boiling and, hence, to prevent the core from entering into the primary phase of a severe accident. Nevertheless, the grace time up to boiling onset is greatly enhanced in comparison to a more traditional homogeneous core design, and only an extremely low fraction of the fuel (<0.1%) enters into melting at the end of this phase. A sensitivity analysis shows that, due to the inherent neutronic characteristics of such a core, the gagging scheme plays a major role on the core behavior: indeed, an improved 4-zones gagging scheme, associated with an enhanced control rod drive line expansion feed-back effect, finally prevents the core from entering into sodium boiling. This major conclusion highlights both the progress already accomplished and the need for more detailed future analyses, particularly concerning: the neutronic burn-up scheme, the modeling of the diagrid effect and the control rod drive line expansion feed-backs, as well as the primary/secondary systems thermal-hydraulics behavior. (authors)

  19. Evaluating Tidal Marsh Sustainability in the Face of Sea-Level Rise: A Hybrid Modeling Approach Applied to San Francisco Bay

    E-Print Network [OSTI]

    Kelly, Maggi

    2011-01-01T23:59:59.000Z

    on sedimentation and intertidal mudflat change in San Pablowill transition to a mudflat [9,31]. When topographicallybetween tidal marsh and mudflat habitats according to the

  20. A COMPUTATIONAL ANALYSIS OF THE OPTIMAL POWER FLOW PROBLEM Baha Alzalg, Catalina Anghel, Wenying Gan, Qing Huang, Mustazee Rahman, Alex Shum

    E-Print Network [OSTI]

    algorithms to handle this problem for the e - 1 security constrained optimal power flow problem. We also.3. The MATPOWER package 4 2.4. Graph theoretic notions 4 3. Security constrained optimal power flow 5 3, such as the breakdown of a generator or a fault in some transmission line. The importance of being able to supply power

  1. TEA - a linear frequency domain finite element model for tidal embayment analysis

    E-Print Network [OSTI]

    Westerink, Joannes J.

    1984-01-01T23:59:59.000Z

    A frequency domain (harmonic) finite element model is developed for the numerical prediction of depth average circulation within small embayments. Such embayments are often characterized by irregular boundaries and bottom ...

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

    E-Print Network [OSTI]

    Durham, Donald L

    1967-01-01T23:59:59.000Z

    27 27 27 28 33 41 54 62 68 74 REFERENCES APPENDIX A LIST OF SYMBOLS APPENDIX B SIZE DETERMINATION OF SUBSURFACE BUOY AND ANCHOR APPENDIX C MATHEMATICAL DEVELOPMENT OF LINEAR EQUATIONS INVOLVING THE FIVE FOURIER COEFFICIENTS APPENDIX D... LINE SEA SURFACE SUBSURFACE BUOY 0 Ol 3/8 INCH CHAIN N ~&4 OEC/HP CURRENT ME TER 7/32 INCH GALV WIRE ~Y TJ SHACKLE ? 3/8 INCH THIMBLE ? 1/4 INCH SWIVEL ? 1500 LBS WORKING LOAD BRAINCON CURRENT METER 0 Ol ? ANCHOR RELEASE BOTTC/M 1000...

  3. Analysis and interpretation of tidal currents in the coastal boundary layer

    E-Print Network [OSTI]

    May, Paul Wesley, 1950-

    1979-01-01T23:59:59.000Z

    Concern with the impact of human activities on the coastal region of the world's oceans has elicited interest in the so-called "coastal boundary layer"-that band of water adjacent to the coast where ocean currents adjust ...

  4. Earth Tidal Analysis At Raft River Geothermal Area (1980) | Open Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE FacilityDimondale,South,Earlsboro, Oklahoma: EnergyEnergy

  5. Earth Tidal Analysis At Raft River Geothermal Area (1982) | Open Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE FacilityDimondale,South,Earlsboro, Oklahoma: EnergyEnergyInformation Raft

  6. Earth Tidal Analysis At Raft River Geothermal Area (1984) | Open Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE FacilityDimondale,South,Earlsboro, Oklahoma: EnergyEnergyInformation

  7. Earth Tidal Analysis At Salton Sea Geothermal Area (1980) | Open Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOE FacilityDimondale,South,Earlsboro, Oklahoma:

  8. Fracture orientation analysis by the solid earth tidal strain method | 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdf Jump to:ar-80m.pdfFillmoreGabbsSalonga, NewCornersFoxFractureEnergy

  9. Earth Tidal Analysis At East Mesa Geothermal Area (1984) | Open Energy

    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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open Jump to:(RES-AEI) |Rock Geothermal

  10. Contents course 424304 / 2011 1 Exergy analysis

    E-Print Network [OSTI]

    Zevenhoven, Ron

    energy 2c.6 Tidal energy, Ocean thermal energy conversion (OTEC), osmotic power 3. ThermodynamicsContents course 424304 / 2011 1 Exergy analysis 1.1 Exergy vs. energy 1.2 Reversible work radiation 2a.8 Environmental radiation 2b Solar energy (thermal, PV, TIR) 2b.1 Solar radiation 2b.2 Photo

  11. A discussion of the relationship between the tidal influence of the moon and the periodical flow of an oil well /

    E-Print Network [OSTI]

    Stillwell, Jerry Edward.

    additional investigations may be conducted. Bartlesville, Okla. February 1919. Ill TABLE OF 00 FT EFTS. Title Page I Preface IX Table of Contents III List of Gurve Sheets IV List of Tables j The Text 1-16 History of Shriver Ho. 3 1-8 Explanation... LIST OF CURVE SHEETS Page Ho. 1 Hov. 4, 1917 to Hov. 5, 1917 17 Hov 2 Hov. 6, 1917 to Hov. 7, 1917 18 Ho. 3 Hov. 7, 1917 to Hov. 9, 1917 19 Ho. ' 4 Hov. 9, 1917 to Hov. 10, 1917 20 Ho. 5 Hov. 10, 1917 to Hov. 12, 1917 21 Ho. 6 Hov. 12, 1917...

  12. TIDAL TAIL EJECTION AS A SIGNATURE OF TYPE Ia SUPERNOVAE FROM WHITE DWARF MERGERS

    SciTech Connect (OSTI)

    Raskin, Cody; Kasen, Daniel [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2013-07-20T23:59:59.000Z

    The merger of two white dwarfs may be preceded by the ejection of some mass in ''tidal tails,'' creating a circumstellar medium around the system. We consider the variety of observational signatures from this material, which depend on the lag time between the start of the merger and the ultimate explosion (assuming one occurs) of the system in a Type Ia supernova (SN Ia). If the time lag is fairly short, then the interaction of the supernova ejecta with the tails could lead to detectable shock emission at radio, optical, and/or X-ray wavelengths. At somewhat later times, the tails produce relatively broad NaID absorption lines with velocity widths of the order of the white dwarf escape speed ({approx}1000 km s{sup -1}). That none of these signatures have been detected in normal SNe Ia constrains the lag time to be either very short ({approx}< 100 s) or fairly long ({approx}> 100 yr). If the tails have expanded and cooled over timescales {approx}10{sup 4} yr, then they could be observable through narrow NaID and Ca II H and K absorption lines in the spectra, which are seen in some fraction of SNe Ia. Using a combination of three-dimensional and one-dimensional hydrodynamical codes, we model the mass loss from tidal interactions in binary systems, and the subsequent interactions with the interstellar medium, which produce a slow-moving, dense shell of gas. We synthesize NaID line profiles by ray casting through this shell, and show that in some circumstances tidal tails could be responsible for narrow absorptions similar to those observed.

  13. THE TIDAL ORIGIN OF THE MAGELLANIC STREAM AND THE POSSIBILITY OF A STELLAR COUNTERPART

    SciTech Connect (OSTI)

    Diaz, Jonathan D.; Bekki, Kenji, E-mail: jdiaz@ast.cam.ac.uk [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 (Australia)

    2012-05-01T23:59:59.000Z

    We present an N-body model that reproduces the morphology and kinematics of the Magellanic Stream (MS), a vast neutral hydrogen (H I) structure that trails behind the Large and Small Magellanic Clouds (LMC and SMC, respectively) in their orbit about the Milky Way (MW). After investigating 8 Multiplication-Sign 10{sup 6} possible orbits consistent with the latest proper motions, we adopt an orbital history in which the LMC and SMC have only recently become a strongly interacting binary pair. We find that their first close encounter {approx}2 Gyr ago provides the necessary tidal forces to disrupt the disk of the SMC and thereby create the MS. The model also reproduces the on-sky bifurcation of the two filaments of the MS, and we suggest that a bound association with the MW is required to reproduce the bifurcation. Additional H I structures are created during the tidal evolution of the SMC disk, including the Magellanic Bridge, the 'Counter-Bridge', and two branches of leading material. Insights into the chemical evolution of the LMC are also provided, as a substantial fraction of the material stripped away from the SMC is engulfed by the LMC. Lastly, we compare three different N-body realizations of the stellar component of the SMC, which we model as a pressure-supported spheroid motivated by recent kinematical observations. We find that an extended spheroid is better able to explain the stellar periphery of the SMC, and the tidal evolution of the spheroid may imply the existence of a stellar stream akin to the gaseous MS.

  14. MHK Projects/Willapa Bay Tidal Power 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend < MHK Projects Jump to:Vicksburg BendWillapa Bay Tidal Power

  15. MHK Technologies/Sihwa tidal barrage power 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 onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRose Bend < MHKconverter < MHK Technologies Jump to:Sihwa tidal

  16. TIDAL ENERGY SITE RESOURCE ASSESSMENT: TECHNICAL SPECIFICATIONS, BEST PRACTICES AND CASE STUDIES

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesis of 2D Alloys & Heterostructures |TIDAL ENERGY

  17. A Synthesis of Environmental and Plant Community Data for Tidal Wetland Restoration Planning in the Lower Columbia River and Estuary

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Borde, Amy B.; Cullinan, Valerie I.

    2013-12-01T23:59:59.000Z

    This report reanalyzes and synthesizes previously existing environmental and plant community data collected by PNNL at 55 tidal wetlands and 3 newly restored sites in the lower Columbia River and estuary (LCRE) between 2005 and 2011. Whereas data were originally collected for various research or monitoring objectives of five studies, the intent of this report is to provide only information that will have direct utility in planning tidal wetland restoration projects. Therefore, for this report, all tidal wetland data on plants and the physical environment, which were originally developed and reported by separate studies, were tabulated and reanalyzed as a whole. The geographic scope of the data collected in this report is from Bonneville Lock and Dam to the mouth of the Columbia River

  18. Simple I/O-efficient flow accumulation on grid terrains Herman Haverkort

    E-Print Network [OSTI]

    Haverkort, Herman

    Simple I/O-efficient flow accumulation on grid terrains Herman Haverkort TU Eindhoven Jeffrey #12;Drainage network analysis 1 2­5 6­12 13­50 flooding flow routing flow accumulation compute network analysis flow routingwatershed labelling flow accumulation #12;Analysing I/O-efficiency main

  19. 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

    2013-07-15T23:59:59.000Z

    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...

  20. GRB060218 AS A TIDAL DISRUPTION OF A WHITE DWARF BY AN INTERMEDIATE-MASS BLACK HOLE

    SciTech Connect (OSTI)

    Shcherbakov, Roman V.; Reynolds, Christopher S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Pe'er, Asaf [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Haas, Roland [Theoretical AstroPhysics Including Relativity, California Institute of Technology, Pasadena, CA 91125 (United States); Bode, Tanja; Laguna, Pablo [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2013-06-01T23:59:59.000Z

    The highly unusual pair of a gamma-ray burst (GRB) GRB060218 and an associated supernova, SN2006aj, has puzzled theorists for years. A supernova shock breakout and a jet from a newborn stellar mass compact object have been proposed to explain this pair's multiwavelength signature. Alternatively, we propose that the source is naturally explained by another channel: the tidal disruption of a white dwarf (WD) by an intermediate-mass black hole (IMBH). This tidal disruption is accompanied by a tidal pinching, which leads to the ignition of a WD and a supernova. Some debris falls back onto the IMBH, forms a disk, which quickly amplifies the magnetic field, and launches a jet. We successfully fit soft X-ray spectra with the Comptonized blackbody emission from a jet photosphere. The optical/UV emission is consistent with self-absorbed synchrotron emission from the expanding jet front. The temporal dependence of the accretion rate M-dot (t) in a tidal disruption provides a good fit to the soft X-ray light curve. The IMBH mass is found to be about 10{sup 4} M{sub Sun} in three independent estimates: (1) fitting the tidal disruption M-dot (t) to the soft X-ray light curve, (2) computing the jet base radius in a jet photospheric emission model, and (3) inferring the mass of the central black hole based on the host dwarf galaxy's stellar mass. The position of the supernova is consistent with the center of the host galaxy, while the low supernova ejecta mass is consistent with that of a WD. The high expected rate of tidal disruptions in dwarf galaxies is consistent with one source observed by the Swift satellite over several years at a distance of 150 Mpc measured for GRB060218. Encounters with WDs provide much fuel for the growth of IMBHs.

  1. Ecology of Juvenile Salmon in Shallow Tidal Freshwater Habitats of the Lower Columbia River, 2007–2010

    SciTech Connect (OSTI)

    Johnson, Gary E.; Storch, Adam; Skalski, J. R.; Bryson, Amanda J.; Mallette, Christine; Borde, Amy B.; Van Dyke, E.; Sobocinski, Kathryn L.; Sather, Nichole K.; Teel, David; Dawley, Earl M.; Ploskey, Gene R.; Jones, Tucker A.; Zimmerman, Shon A.; Kuligowski, D. R.

    2011-03-01T23:59:59.000Z

    The TFM study was designed to investigate the ecology and early life history of juvenile salmonids within shallow (<5 m) tidal freshwater habitats of the LCRE. We started collecting field data in June 2007. Since then, monthly sampling has occurred in the vicinity of the Sandy River delta (rkm 192–208) and at other sites and times in lower river reaches of tidal freshwater (rkm 110 to 141). This report provides a comprehensive synthesis of data covering the field period from June 2007 through April 2010.

  2. Non-linear evolution of the tidal angular momentum of protostructures II: non-Gaussian initial conditions

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1997-04-14T23:59:59.000Z

    The formalism that describes the non-linear growth of the angular momentum L of protostructures from tidal torques in a Friedmann Universe, as developed in a previous paper, is extended to include non-Gaussian initial conditions. We restrict our analysis here to a particular class of non-Gaussian primordial distributions, namely multiplicative models. In such models, strongly correlated phases are produced by obtaining the gravitational potential via a nonlinear local transformation of an underlying Gaussian random field. The dynamical evolution of the system is followed by describing the trajectories of fluid particles using second-order Lagrangian perturbation theory. In the Einstein-de Sitter universe, the lowest-order perturbative correction to the variance of the linear angular momentum of collapsing structures grows as t^8/3 for generic non-Gaussian statistics, which contrasts with the t^10/3 growth rate characteristic of Gaussian statistics. This is a consequence of the fact that the lowest-order perturbative spin contribution in the non-Gaussian case arises from the third moment of the gravitational potential, which is identically zero for a Gaussian field. Evaluating these corrections at the maximum expansion time of the collapsing structure, we find that these non-Gaussian and non-linear terms can be as high as the linear estimate, without the degree of non-Gaussianity as quantified by skewness and kurtosis of the density field being unacceptably large. The results suggest that higher-order terms in the perturbative expansion may contribute significantly to galactic spin which contrasts with the straightforward Gaussian case.

  3. Conformally curved binary black hole initial data including tidal deformations and outgoing radiation

    E-Print Network [OSTI]

    Nathan K. Johnson-McDaniel; Nicolas Yunes; Wolfgang Tichy; Benjamin J. Owen

    2009-07-06T23:59:59.000Z

    (Abridged) By asymptotically matching a post-Newtonian (PN) metric to two tidally perturbed Schwarzschild metrics, we generate approximate initial data (in the form of a 4-metric) for a nonspinning black hole binary in a circular orbit. We carry out this matching through O(v^4) in the binary's orbital velocity v, so the resulting data are conformally curved. Far from the holes, we use the appropriate PN metric that accounts for retardation, which we construct using the highest-order PN expressions available to compute the binary's past history. The data set's uncontrolled remainders are thus O(v^5) throughout the timeslice; we also generate an extension to the data set that has uncontrolled remainders of O(v^6) in the purely PN portion of the timeslice (i.e., not too close to the holes). The resulting data are smooth, since we join all the metrics together by smoothly interpolating between them. We perform this interpolation using transition functions constructed to avoid introducing excessive additional constraint violations. Due to their inclusion of tidal deformations and outgoing radiation, these data should substantially reduce the initial spurious ("junk") radiation observed in current simulations that use conformally flat initial data. Such reductions in the nonphysical components of the initial data will be necessary for simulations to achieve the accuracy required to supply Advanced LIGO and LISA with the templates necessary for parameter estimation.

  4. The flattenings of the layers of rotating planets and satellites deformed by a tidal potential

    E-Print Network [OSTI]

    Folonier, Hugo; Kholshevnikov, Konstantin V

    2015-01-01T23:59:59.000Z

    We consider the Clairaut theory of the equilibrium ellipsoidal figures for differentiated non-homogeneous bodies in non-synchronous rotation adding to it a tidal deformation due to the presence of an external gravitational force. We assume that the body is a fluid formed by $n$ homogeneous layers of ellipsoidal shape and we calculate the external polar flattenings and the mean radius of each layer, or, equivalently, their semiaxes. To first order in the flattenings, the general solution can be written as $\\epsilon_k={\\cal H}_k*\\epsilon_h$ and $\\mu_k={\\cal H}_k*\\mu_h$, where $\\cal{H}_k$ is a characteristic coefficient for each layer which only depends on the internal structure of the body and $\\epsilon_h, \\mu_h$ are the flattenings of the equivalent homogeneous problem. For the continuous case, we study the Clairaut differential equation for the flattening profile, using the Radau transformation to find the boundary conditions when the tidal potential is added. Finally, the theory is applied to several example...

  5. Using Neutron Star Observations to Determine Crust Thicknesses, Moments of Inertia, and Tidal Deformabilities

    E-Print Network [OSTI]

    Andrew W. Steiner; Stefano Gandolfi; Farrukh J. Fattoyev; William G. Newton

    2015-01-25T23:59:59.000Z

    We perform a systematic assessment of models for the equation of state (EOS) of dense matter in the context of recent neutron star mass and radius measurements to obtain a broad picture of the structure of neutron stars. We demonstrate that currently available neutron star mass and radius measurements provide strong constraints on moments of inertia, tidal deformabilities, and crust thicknesses. A measurement of the moment of inertia of PSR J0737-3039A with 10% error, without any other information from observations, will constrain the EOS over a range of densities to within 50%$-$60%. We find tidal deformabilities between 0.6 and $6\\times 10^{36}$ g cm$^{2}$ s$^{2}$ (to 95% confidence) for $M=1.4~\\mathrm{M}_{\\odot}$, and any measurement which constrains this range will provide an important constraint on dense matter. The crustal fraction of the moment of inertia can be as large as 10% for $M=1.4~\\mathrm{M}_{\\odot}$ permitting crusts to have a large enough moment of inertia reservoir to explain glitches in the Vela pulsar even with a large amount of superfluid entrainment. Finally, due to the uncertainty in the equation of state, there is at least a 40% variation in the thickness of the crust for a fixed mass and radius, which implies that future simulations of the cooling of a neutron star crust which has been heated by accretion will need to take this variation into account.

  6. Variations of net ecosystem CO2 exchange in a tidal inundated wetland: Coupling MODIS and towerbased fluxes

    E-Print Network [OSTI]

    Chen, Jiquan

    .e., biomass), nutrient availability and use, and species composition in coastal Chongming Island, Shanghai, but gradual changes of water level can play an important role in deter- mining the net ecosystem CO2 exchange multiple towers to detect the changes along the tidal gradient, but the high cost and maintenance hinder

  7. Comparison of SF6 and Fluorescein as Tracers for Measuring Transport Processes in a Large Tidal River

    E-Print Network [OSTI]

    Ho, David

    Comparison of SF6 and Fluorescein as Tracers for Measuring Transport Processes in a Large Tidal SF6 as tracers of advection and longitudinal dispersion from a dual tracer release experiment of SF6 were injected into the Hudson River at an averaged depth of 9.5 m, 1 m above the bottom, near

  8. 2013 American Geophysical Union. All Rights Reserved. Tidal dissipation in the early Eocene and implications for ocean mixing

    E-Print Network [OSTI]

    Holland, Jeffrey

    © 2013 American Geophysical Union. All Rights Reserved. Tidal dissipation in the early Eocene this article as doi: 10.1002/grl.50510 AcceptedArticle #12;© 2013 American Geophysical Union. All Rights Passage and Tasman Gateways AcceptedArticle #12;© 2013 American Geophysical Union. All Rights Reserved

  9. Tidal effects on net ecosystem exchange of carbon in an estuarine wetland Haiqiang Guo a,c

    E-Print Network [OSTI]

    Noormets, Asko

    Tidal effects on net ecosystem exchange of carbon in an estuarine wetland Haiqiang Guo a,c , Asko, Shanghai, China b Southern Global Change Program, USDA Forest Service, Raleigh, NC, USA c Department concentrations of carbon dioxide (CO2) and methane (CH4) have stimulated great interest in studying the carbon

  10. Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern Maine, a strongly tidally mixed coastal region

    E-Print Network [OSTI]

    Townsend, David W.

    Environmental links to interannual variability in shellfish toxicity in Cobscook Bay and eastern e i n f o Keywords: Harmful algal blooms Gulf of Maine Cobscook Bay Shellfish toxicity a b s t r a c of Cobscook Bay, where strong tidal mixing tends to reduce seasonal variability in oceanographic properties

  11. GEOPHYSICAL RESEARCH LETTERS, VOL. 28, NO. 5, PAGES 811-814, MARCH 1, 2001 Parameterizing Tidal Dissipation over Rough

    E-Print Network [OSTI]

    Jayne, Steven

    of barotropic tidal energy. The first line of evidence comes from observations of mix- ing in the abyssal Brazil ocean, the energy flux carried by internal waves generated over rough topog- raphy dominates the energy issues. The first is whether including a parameterization for internal wave energy-flux in a model

  12. Tidally-induced thermonuclear Supernovae Stephan Rosswog1, Enrico Ramirez-Ruiz2, W. Raphael Hix3

    E-Print Network [OSTI]

    Rosswog, Stephan

    Tidally-induced thermonuclear Supernovae Stephan Rosswog1, Enrico Ramirez-Ruiz2, W. Raphael Hix3 1 in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate

  13. A three-dimensional analysis of the flow and heat transfer for the modified chemical vapor deposition process including buoyancy, variable properties, and tube rotation

    SciTech Connect (OSTI)

    Lin, Y.T.; Choi, M.; Greif, R. (Univ. of California, Berkeley (USA))

    1991-05-01T23:59:59.000Z

    A study has been made of the heat transfer, flow, and particle deposition relative to the modified chemical vapor deposition (MCVD) process. The effects of variable properties, buoyancy, and tube rotation have been included in the study. The resulting three-dimensional temperature and velocity fields have been obtained for a range of conditions. The effects of buoyancy result in asymmetric temperature and axial velocity profiles with respect to the tube axis. Variable properties cause significant variations in the axial velocity along the tube and in the secondary flow in the region near the torch. Particle trajectories are shown to be strongly dependent on the tube rotation and are helices for large rotational speeds. The component of secondary flow in the radial direction is compared to the thermophoretic velocity, which is the primary cause of particle deposition in the MCVD process. Over the central portion of the tube the radial component of the secondary flow is most important in determining the motion of the particles.

  14. Non-dissipative tidal synchronization in accreting binary white dwarf systems

    E-Print Network [OSTI]

    Etienne Racine; E. Sterl Phinney; Phil Arras

    2007-09-18T23:59:59.000Z

    We study a non-dissipative hydrodynamical mechanism that can stabilize the spin of the accretor in an ultra-compact double white dwarf binary. This novel synchronization mechanism relies on a nonlinear wave interaction spinning down the background star. The essential physics of the synchronization mechanism is summarized as follows. As the compact binary coalesces due to gravitational wave emission, the largest star eventually fills its Roche lobe and accretion starts. The accretor then spins up due to infalling material and eventually reaches a spin frequency where a normal mode of the star is resonantly driven by the gravitational tidal field of the companion. If the resonating mode satisfies a set of specific criteria, which we elucidate in this paper, it exchanges angular momentum with the background star at a rate such that the spin of the accretor locks at this resonant frequency, even though accretion is ongoing. Some of the accreted angular momentum that would otherwise spin up the accretor is fed back into the orbit through this resonant tidal interaction. Two modes capable of stabilizing the accretor's spin are the l=4,m=2 and l=5,m=3 CFS unstable hybrid r-modes, which stabilize the spin of the accretor at frequency 2.6 and 1.5 times the binary's orbital frequency respectively. Since the stabilization mechanism relies on continuously driving a mode at resonance, its lifetime is limited since eventually the mode amplitude saturates due to non-linear mode-mode coupling. Rough estimates of the lifetime of the effect lie from a few orbits to millions of years.

  15. On the tidal interaction of massive extra-solar planets on highly eccentric orbit

    E-Print Network [OSTI]

    P. B. Ivanov; J. C. B. Papaloizou

    2003-10-09T23:59:59.000Z

    In this paper we develop a theory of disturbances induced by the stellar tidal field in a fully convective slowly rotating planet orbiting on a highly eccentric orbit around a central star. We show that there are two contributions to the mode energy and angular momentum gain due to impulsive tidal interaction: a) 'the quasi-static' contribution which requires dissipative processes operating in the planet; b) the dynamical contribution associated with excitation of modes of oscillation. These contributions are obtained self-consistently from a single set of the governing equations. We calculate a critical 'equilibrium' value of angular velocity of the planet \\Omega_{crit} determined by the condition that action of the dynamical tides does not alter the angular velocity at that rotation rate. We show that this can be much larger than the corresponding rate associated with quasi-static tides and that at this angular velocity, the rate of energy exchange is minimised. We also investigate the conditions for the stochastic increase in oscillation energy that may occur if many periastron passages are considered. We make some simple estimates of time scale of circularization of initially eccentric orbit due to tides, using a realistic model of the planet, for orbits withperiods after circularization typical of those observed for extra-solar planets P_{obs} > 3days. We find that dynamic tides could have produced a very large decrease of the semi-major axis of a planet with mass of the order of the Jupiter mass M_{J} and final periods P_{obs} < 4.5days on a time-scale < a few Gyrs. We also discuss several unresolved issues in the context of the scenario of the orbit circularization due to dynamic tides.

  16. Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings 

    E-Print Network [OSTI]

    San Andres, Luis

    2009-01-01T23:59:59.000Z

    The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....

  17. Floating Robots Track Water Flow With Smartphones

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

    floating together and covering the whole area of study." According to Wu, each floating sensor will be taking measurements of the tidal stage, velocity, and temperature and...

  18. SDSS J074511.56+194926.5: Discovery of a metal-rich and tidally distorted extremely low mass white dwarf

    SciTech Connect (OSTI)

    Gianninas, A.; Barber, Sara D.; Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Hermes, J. J.; Harrold, Samuel T. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States); Dufour, P., E-mail: alexg@nhn.ou.edu [Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7 (Canada)

    2014-02-01T23:59:59.000Z

    We present the discovery of an unusual, tidally distorted extremely low mass white dwarf (WD) with nearly solar metallicity. Radial velocity measurements confirm that this is a compact binary with an orbital period of 2.6975 hr and a velocity semi-amplitude of K = 108.7 km s{sup –1}. Analysis of the hydrogen Balmer lines yields an effective temperature of T {sub eff} = 8380 K and a surface gravity of log g = 6.21 that in turn indicate a mass of M = 0.16 M {sub ?} and a cooling age of 4.2 Gyr. In addition, a detailed analysis of the observed metal lines yields abundances of log (Mg/H) = –3.90, log (Ca/H) = –5.80, log (Ti/H) = –6.10, log (Cr/H) = –5.60, and log (Fe/H) = –4.50, similar to the sun. We see no evidence of a debris disk from which these metals would be accreted, though the possibility cannot entirely be ruled out. Other potential mechanisms to explain the presence of heavy elements are discussed. Finally, we expect this system to ultimately undergo unstable mass transfer and merge to form a ?0.3-0.6 M {sub ?} WD in a few Gyr.

  19. Continuous Flow Liquid Microjunction Surface Sampling Probe Connected On-line with HPLC/MS for Spatially Resolved Analysis of Small Molecules and Proteins

    SciTech Connect (OSTI)

    Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL

    2013-01-01T23:59:59.000Z

    RATIONALE: A continuous flow liquid microjunction surface sampling probe extracts soluble material from surfaces for direct ionization and detection by MS. Demonstrated here is the on-line coupling of such a probe with HPLC/MS enabling extraction, separation and detection of small molecules and proteins from surfaces in a spatially resolved (~0.5 mm diameter spots) manner. Methods: A continuous flow liquid microjunction surface sampling probe was connected to a 6-port, 2-position valve for extract collection and injection to an HPLC column. A QTRAP 5500 hybrid triple quadrupole linear ion trap equipped with a Turbo V ion source operated in positive ESI mode was used for all experiments. System operation was tested with extraction, separation and detection of propranolol and associated metabolites from drug dosed tissues and proteins from dried sheep blood spots on paper. Results: Confirmed in the tissue were the parent drug and two different hydroxypropranolol glucuronides. The mass spectrometric response for these compounds from different locations in the liver showed an increase with increasing extraction time (5, 20 and 40 s extractions). For on-line separation and detection/identification of extracted proteins from dried sheep blood spots, two major protein peaks dominated the chromatogram and could be correlated with the expected masses for the hemoglobin and chains. Conclusions: Spatially resolved sampling, separation, and detection of small molecules and proteins from surfaces can be accomplished using a continuous flow liquid microjunction surface sampling probe coupled on-line with HPLC/MS detection.

  20. Documenting Organizational Process Flow Modeling

    E-Print Network [OSTI]

    Schweik, Charles M.

    1 Documenting Organizational Processes or Process Flow Modeling Analysis Phase ­ Three Steps that describes (1) the current, and (2) the future structure of an organizational process ·"Natural language ­ An overview of an organizational system showing · system boundaries, · external entities that interact

  1. Low volume flow meter

    DOE Patents [OSTI]

    Meixler, Lewis D. (East Windsor, NJ)

    1993-01-01T23:59:59.000Z

    The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

  2. Solyndra Facts vs. Fiction: Cash Flow Modeling

    Broader source: Energy.gov [DOE]

    Questions have been raised about a quote selectively pulled from an Aug. 20, 2009 email to make it look like Solyndra would run out of cash by Sept. 2011. To be clear, the analysis addressed in that email did not refer to Solyndra’s corporate cash flow, but rather the cash flow for a subsidiary of Solyndra – the “Fab 2 Project Company.

  3. Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30T23:59:59.000Z

    Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Chinook/CKPUG.cfm); the fish used in this experiment were hatchery raised and their populations are not in danger of depletion. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Experimental results indicate that non-lethal, low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  4. An unstructured C-grid based method for 3-D global ocean dynamics: Free-surface formulations and tidal test cases

    E-Print Network [OSTI]

    Peltier, W. Richard

    and tidal test cases G.R. Stuhne *, W.R. Peltier Department of Physics, University of Toronto, 60 St. George rights reserved. 1. Introduction In a previous paper (Stuhne and Peltier, 2006, hereafter SP), we

  5. Area Solar energy production BACKGROUND -All renewable energies, except for geothermal and tidal, derive their energy from the sun. By harnessing the power of

    E-Print Network [OSTI]

    Keinan, Alon

    Area Solar energy production ­ BACKGROUND - All renewable energies installations. Advantages: · A renewable form of energy - "Locks up" carbon, except for geothermal and tidal, derive their energy from the sun

  6. Bacteria in shear flow

    E-Print Network [OSTI]

    Marcos, Ph.D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

  7. Dispersed flow film boiling

    E-Print Network [OSTI]

    Yoder, Graydon L.

    1980-01-01T23:59:59.000Z

    Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

  8. Measurement of thermodynamics using gradient flow

    E-Print Network [OSTI]

    Masakiyo Kitazawa; Masayuki Asakawa; Tetsuo Hatsuda; Takumi Iritani; Etsuko Itou; Hiroshi Suzuki

    2014-12-15T23:59:59.000Z

    We analyze bulk thermodynamics and correlation functions of the energy-momentum tensor in pure Yang-Mills gauge theory using the energy-momentum tensor defined by the gradient flow and small flow time expansion. Our results on thermodynamic observables are consistent with those obtained by the conventional integral method. The analysis of the correlation function of total energy supports the energy conservation. It is also addressed that these analyses with gradient flow require less statistics compared with the previous methods. All these results suggest that the energy-momentum tensor can be successfully defined and observed on the lattice with moderate numerical costs with the gradient flow.

  9. Flow characteristics in underground coal gasification

    SciTech Connect (OSTI)

    Chang, H.L.; Himmelblau, D.M.; Edgar, T.F.

    1982-01-01T23:59:59.000Z

    During the underground coal gasification field test at the Hoe Creek site No. 2, Wyoming, helium pulses were introduced to develop information to characterize the flow field, and to estimate the coefficients in dispersion models of the flow. Quantitative analysis of the tracer response curves shows an increasing departure from a plug flow regime with time because of the combined effects of the free and forced convection in addition to the complex non-uniformity of the flow field. The Peclet number was a function of temperature, pressure, gas recovery and characteristic velocity, as well as the split of the gas between the parallel streams in the model. 17 refs.

  10. Multiphase flow calculation software

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-04-15T23:59:59.000Z

    Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

  11. Parametric analysis of radiative-convective heat transfer around a circular cylinder in a cross flow using the finite volume radiation solution method

    SciTech Connect (OSTI)

    Lee, K.H.; Lee, J.S.; Choi, M. [Seoul National Univ. (Korea, Republic of). Dept. of Mechanical Engineering

    1996-02-09T23:59:59.000Z

    In the outside vapor deposition (OVD) process, silica particles are deposited by thermophoretic force on the surface of a cylinder. This process is associated with complex physical phenomena such as heat transfer between a torch and a cylinder, chemical reaction for silica particle formation, and particle deposition. Since the OVD process is carried out in a very high temperature environment, radiative heat transfer should be taken into consideration. Here, the radiative-convective heat transfer around a circular cylinder in a cross flow of a radiating gas has been numerically analyzed using the finite volume radiation solution method in a nonorthogonal coordinate system. The cross-flow Reynolds number based on the cylinder diameter is 40, and the fluid Prandtl number is assumed to be 0.7. The radiative heat transfer coupled with convection is reasonably predicted by the finite volume radiation solution method. Distributions of the local Nusselt number are investigated according to the variation of radiation parameters such as conduction-to-radiation parameter, optical thickness, scattering albedo, and cylinder wall emissivity.

  12. Simultaneous solution algorithms for Eulerian-Eulerian gas-solid flow models: Stability analysis and convergence behaviour of a point and a plane solver

    SciTech Connect (OSTI)

    Wilde, Juray de [Laboratorium voor Petrochemische Techniek, Ghent University, Krijgslaan 281, Blok S5, B-9000 Ghent (Belgium) and Fluid Mechanics Laboratory, Department of Fluid, Heat and Combustion Mechanics, Ghent University, St.-Pietersnieuwstraat 41, B-9000 Ghent (Belgium)]. E-mail: Guray.Marin@UGent.be; Vierendeels, Jan [Fluid Mechanics Laboratory, Department of Fluid, Heat and Combustion Mechanics, Ghent University, St.-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); Heynderickx, Geraldine J. [Laboratorium voor Petrochemische Techniek, Ghent University, Krijgslaan 281, Blok S5, B-9000 Ghent (Belgium); Marin, Guy B. [Laboratorium voor Petrochemische Techniek, Ghent University, Krijgslaan 281, Blok S5, B-9000 Ghent (Belgium)

    2005-07-20T23:59:59.000Z

    Simultaneous solution algorithms for Eulerian-Eulerian gas-solid flow models are presented and their stability analyzed. The integration algorithms are based on dual-time stepping with fourth-order Runge-Kutta in pseudo-time. The domain is solved point or plane wise. The discretization of the inviscid terms is based on a low-Mach limit of the multi-phase preconditioned advection upstream splitting method (MP-AUSMP). The numerical stability of the simultaneous solution algorithms is analyzed in 2D with the Fourier method. Stability results are compared with the convergence behaviour of 3D riser simulations. The impact of the grid aspect ratio, preconditioning, artificial dissipation, and the treatment of the source terms is investigated. A particular advantage of the simultaneous solution algorithms is that they allow a fully implicit treatment of the source terms which are of crucial importance for the Eulerian-Eulerian gas-solid flow models and their solution. The numerical stability of the optimal simultaneous solution algorithm is analyzed for different solids volume fractions and gas-solid slip velocities. Furthermore, the effect of the grid resolution on the convergence behaviour and the simulation results is investigated. Finally, simulations of the bottom zone of a pilot-scale riser with a side solids inlet are experimentally validated.

  13. Tides and Tidal Capture in post-Main Sequence Binaries: A Period Gap for Planets Around White Dwarfs

    E-Print Network [OSTI]

    Nordhaus, J; Ibgui, L; Goodman, J; Burrows, A

    2010-01-01T23:59:59.000Z

    The presence of a close, low-mass companion is thought to play a substantial and perhaps necessary role in shaping post-Asymptotic Giant Branch and Planetary Nebula outflows. During post-main-sequence evolution, radial expansion of the primary star, accompanied by intense winds, can significantly alter the binary orbit via tidal dissipation and mass loss. To investigate this, we couple stellar evolution models (from the zero-age main-sequence through the end of the post-main sequence) to a tidal evolution code. The binary's fate is determined by the initial masses of the primary and the companion, the initial orbit (taken to be circular), and the Reimer's mass-loss parameter. For a range of these parameters, we determine whether the orbit expands due to mass loss or decays due to tidal torques. Where a common envelope phase (CEP) ensues, we estimate the final orbital separation based on the energy required to unbind the envelope. These calculations predict a period gap for planetary companions to white dwarfs...

  14. Flow characteristics in underground coal gasification

    SciTech Connect (OSTI)

    Chang, H.L.; Himmelblau, D.M.; Edgar, T.F.

    1982-01-01T23:59:59.000Z

    During the Hoe Creek No. 2 (Wyoming) underground-coal-gasification field test, researchers introduced helium pulses to characterize the flow field and to estimate the coefficients in dispersion models of the flow. Flow models such as the axial-dispersion and parallel tanks-in-series models allowed interpretation of the in situ combustion flow field from the residence time distribution of the tracer gas. A quantitative analysis of the Hoe Creek tracer response curves revealed an increasing departure from a plug-flow regime with time, which was due to the combined effects of the free and forced convection in addition to the complex nonuniformity of the flow field. The Peclet number was a function of temperature, pressure, gas recovery, and characteristic velocity, as well as the split of the gas between the parallel streams in the model.

  15. Tidal Downsizing Model. III. Planets from sub-Earths to Brown Dwarfs: structure and metallicity preferences

    E-Print Network [OSTI]

    Nayakshin, Sergei

    2015-01-01T23:59:59.000Z

    We present improved population synthesis calculations in the context of the Tidal Downsizing (TD) hypothesis for planet formation. Our models provide natural explanations and/or quantitative match to exoplanet observations in the following categories: (i) most abundant planets being super-Earths; (ii) cores more massive than $\\sim 5-15 M_\\oplus$ are enveloped by massive metal-rich atmospheres; (iii) the frequency of occurrence of close-in gas giant planets correlates strongly with metallicity of the host star; (iv) no such correlation is found for sub-Neptune planets; (v) presence of massive cores in giant planets; (vi) the composition of gas giant planets is over-abundant in metals compared to their host stars; (vii) this over-abundance decreases with planet's mass, as observed; (viii) a deep valley in the planet mass function between masses of $\\sim 10-20 M_\\oplus$ and $\\sim 100 M_\\oplus$. We provide a number of observational predictions distinguishing the model from Core Accretion: (a) composition of the m...

  16. Evolution of the angular momentum of protogalaxies from tidal torques: Zel'dovich approximation

    E-Print Network [OSTI]

    Paolo Catelan; Tom Theuns

    1996-04-15T23:59:59.000Z

    The growth of the angular momentum L of protogalaxies induced by tidal torques is reconsidered within the Zel'dovich approximation. We obtain a general expression for the ensemble expectation value of the square of L in terms of the first and second invariant of the inertia tensor of the Lagrangian volume enclosing the protoobject's collapsing mass. We then specialize the formalism to the particular case in which this volume is centered on a peak of the smoothed Gaussian density field and approximated by an isodensity ellipsoid. The result is the appropriate analytical estimate for the rms angular momentum of peaks to be compared against simulations that make use of the Hoffman-Ribak algorithm to set up a constrained density field that contains a peak with given shape. Extending the work of Heavens & Peacock, we calculate the joint probability distribution function for several spin parameters and peak mass M using the distribution of peak shapes, for different initial power spectra. The values of observed specific angular momentum versus mass are well fitted by our theoretical isoprobability contours. In contrast, the observed lower values for the specific angular momentum for ellipticals of the same mass cannot be accounted for within our linear regime investigation, highlighting the importance of strongly non-linear phenomena to explain the spin of such objects.

  17. Tidal disruptions in circumbinary discs (I): Star formation, dynamics, and binary evolution

    E-Print Network [OSTI]

    Pau Amaro-Seoane; Patrick Brem; Jorge Cuadra

    2012-12-11T23:59:59.000Z

    In our current interpretation of the hierarchical structure of the universe it is well established that galaxies collide and merge with each other during their lifetime. If massive black holes (MBHs) reside in galactic centres, we expect them to form binaries in galactic nuclei surrounded by a circumbinary disc. If cooling is efficient enough, the gas in the disc will clump and trigger stellar formation in situ. In this first paper we address the evolution of the binary under the influence of the newly formed stars, which form individually and also clustered. We use SPH techniques to evolve the gas in the circumbinary disc and to study the phase of star formation. When the amount of gas in the disc is negligible, we further evolve the system with a high-accurate direct-summation $N-$body code to follow the evolution of the stars, the innermost binary and tidal disruption events (TDEs). For this, we modify the direct N-body code to (i) include treatment of TDEs and to (ii) include "gas cloud particles" that mimic the gas, so that the stellar clusters do not disolve when we follow their infall on to the MBHs. We find that the amount of stars disrupted by either infalling stellar clusters or individual stars is as large as 10^{-4}/yr per binary, higher than expected for typical galaxies.

  18. TURBOVELOCITY STARS: KICKS RESULTING FROM THE TIDAL DISRUPTION OF SOLITARY STARS

    SciTech Connect (OSTI)

    Manukian, Haik; Guillochon, James; Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); O'Leary, Ryan M., E-mail: jfg@ucolick.org [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2013-07-10T23:59:59.000Z

    The centers of most known galaxies host supermassive black holes (SMBHs). In orbit around these black holes are a centrally concentrated distribution of stars, both in single and in binary systems. Occasionally, these stars are perturbed onto orbits that bring them close to the SMBH. If the star is in a binary system, the three-body interaction with the SMBH can lead to large changes in orbital energy, depositing one of the two stars on a tightly-bound orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In this Letter, we show that the disruption of solitary stars can also lead to large positive increases in orbital energy. The kick velocity depends on the amount of mass the star loses at pericenter, but not on the ratio of black hole to stellar mass, and are at most the star's own escape velocity. We find that these kicks are usually too small to result in the ejection of stars from the Milky Way, but can eject the stars from the black hole's sphere of influence, reducing their probability of being disrupted again. We estimate that {approx} 10{sup 5} stars, {approx} 1% of all stars within 10 pc of the galactic center, are likely to have had mass removed by the central black hole through tidal interaction, and speculate that these 'turbovelocity' stars will at first be redder, but eventually bluer, and always brighter than their unharassed peers.

  19. Radio-X-ray Synergy to discover and Study Jetted Tidal Disruption Events

    E-Print Network [OSTI]

    Donnarumma, I

    2015-01-01T23:59:59.000Z

    Observational consequences of tidal disruption of stars (TDEs) by supermassive black holes (SMBHs) can enable us to discover quiescent SMBHs, constrain their mass function, study formation and evolution of transient accretion disks and jet formation. A couple of jetted TDEs have been recently claimed in hard X-rays, challenging jet models, previously applied to $\\gamma$-ray bursts and active galactic nuclei. It is therefore of paramount importance to increase the current sample. In this paper, we find that the best strategy is not to use up-coming X-ray instruments alone, which will yield between several (e-Rosita) and a couple of hundreds (Einstein Probe) events per year below redshift one. We rather claim that a more efficient TDE hunter will be the Square Kilometer Array (SKA) operating {\\it in survey mode} at 1.4 GHz. It may detect up to several hundreds of events per year below $z \\sim 2.5$ with a peak rate of a few tens per year at $z\\approx 0.5$. Therefore, even if the jet production efficiency is {\\it...

  20. Nonpremixed Combustion in an Accelerating Turning Transonic Flow Undergoing Transition

    E-Print Network [OSTI]

    Liu, Feng

    the range of engine operation. Since the flow in a turbine passage is accelerating and power is extracted from the flow, it is possible to add heat without increasing the flow temperature beyond the turbine-blade material limit. Sirignano and Liu1,2 show by thermodynamic analysis that the thrust of aircraft turbojet

  1. Jet Flows Around Microbubbles In Subcooled Boiling , Xiaofeng Pengb

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    Jet Flows Around Microbubbles In Subcooled Boiling Hao Wanga , Xiaofeng Pengb , David M Strong jet flows were observed emanating from micro bubbles on a 100 µm diameter wire during subcooled analysis. The bubble-top jet flows were characterized by a single jet at the bubble top. Both experiments

  2. Freshwater Flow Charts - 1995

    SciTech Connect (OSTI)

    Kaiper, G V

    2003-11-21T23:59:59.000Z

    This report covers the following: (1) Explanation of Charts Showing Freshwater Flow in 1995; (2) Estimated U.S. Freshwater Flow in 1995 (chart); (3) Estimated California Freshwater Flow in 1995 (chart); (4) Estimated New Mexico Freshwater Flow in 1995 (chart); and (5) Web locations and credits.

  3. Portable wastewater flow meter

    DOE Patents [OSTI]

    Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

    1990-01-01T23:59:59.000Z

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  4. Portable wastewater flow meter

    DOE Patents [OSTI]

    Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

    1999-02-02T23:59:59.000Z

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  5. CONSTRAINTS ON THE LIFETIMES OF DISKS RESULTING FROM TIDALLY DESTROYED ROCKY PLANETARY BODIES

    SciTech Connect (OSTI)

    Girven, J.; Gaensicke, B. T.; Marsh, T. R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Brinkworth, C. S.; Hoard, D. W. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Farihi, J. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Koester, D., E-mail: j.m.girven@warwick.ac.uk [Institut fuer Theoretische Physik und Astrophysik, University of Kiel, 24098 Kiel (Germany)

    2012-04-20T23:59:59.000Z

    Spitzer IRAC observations of 15 metal-polluted white dwarfs reveal infrared excesses in the spectral energy distributions of HE 0110-5630, GD 61, and HE 1349-2305. All three of these stars have helium-dominated atmospheres, and their infrared emissions are consistent with warm dust produced by the tidal destruction of (minor) planetary bodies. This study brings the number of metal-polluted, helium and hydrogen atmosphere white dwarfs surveyed with IRAC to 53 and 38, respectively. It also nearly doubles the number of metal-polluted helium-rich white dwarfs found to have closely orbiting dust by Spitzer. From the increased statistics for both atmospheric types with circumstellar dust, we derive a typical disk lifetime of log [t{sub disk}(yr)] = 5.6 {+-} 1.1 (ranging from 3 Multiplication-Sign 10{sup 4} to 5 Multiplication-Sign 10{sup 6} yr). This assumes a relatively constant rate of accretion over the timescale where dust persists, which is uncertain. We find that the fraction of highly metal-polluted helium-rich white dwarfs that have an infrared excess detected by Spitzer is only 23%, compared to 48% for metal-polluted hydrogen-rich white dwarfs, and we conclude from this difference that the typical lifetime of dusty disks is somewhat shorter than the diffusion timescales of helium-rich white dwarf. We also find evidence for higher time-averaged accretion rates onto helium-rich stars compared to the instantaneous accretion rates onto hydrogen-rich stars; this is an indication that our picture of evolved star-planetary system interactions is incomplete. We discuss some speculative scenarios that can explain the observations.

  6. The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultra-Short Periods

    E-Print Network [OSTI]

    Pin-Gao Gu; Doug Lin; Peter Bodenheimer

    2003-03-17T23:59:59.000Z

    We investigate the possibility of substantial inflation of short-period Jupiter-mass planets, as a result of their internal tidal dissipation associated with the synchronization and circularization of their orbits. We employ the simplest prescription based on an equilibrium model with a constant lag angle for all components of the tide. We show that for young Jupiter-mass planets, with a period less than 3 days, an initial radius about 2 Jupiter radii, and an orbital eccentricity greater than 0.2, the energy dissipated during the circularization of their orbits is sufficiently intense and protracted to inflate their sizes up to their Roche radii.

  7. Global helioseismic evidence for a deeply penetrating Solar meridional flow consisting of multiple flow cells

    E-Print Network [OSTI]

    Schad, A; Roth, M

    2013-01-01T23:59:59.000Z

    We use a novel global helioseismic analysis method to infer the meridional flow in the deep Solar interior. The method is based on the perturbation of eigenfunctions of Solar p modes due to meridional flow. We apply this method to time series obtained from Dopplergrams measured by the Michelson Doppler Imager aboard the Solar and Heliospheric Observatory (SOHO) covering the observation period 2004-2010. Our results show evidence that the meridional flow reaches down to the base of the convection zone. The flow profile has a complex spatial structure consisting of multiple flow cells distributed in depth and latitude. Toward the Solar surface, our results are in good agreement with flow measurements from local helioseismology.

  8. A Semiconductor Microlaser for Intracavity Flow Cytometry

    SciTech Connect (OSTI)

    Akhil, O.; Copeland, G.C.; Dunne, J.L.; Gourley, P.L.; Hendricks, J.K.; McDonald, A.E.

    1999-01-20T23:59:59.000Z

    Semiconductor microlasers are attractive components for micro-analysis systems because of their ability to emit coherent intense light from a small aperture. By using a surface-emitting semiconductor geometry, we were able to incorporate fluid flow inside a laser microcavity for the first time. This confers significant advantages for high throughput screening of cells, particulates and fluid analytes in a sensitive microdevice. In this paper we discuss the intracavity microfluidics and present preliminary results with flowing blood and brain cells.

  9. Ultrasonic flow metering system

    DOE Patents [OSTI]

    Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.

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

    E-Print Network [OSTI]

    Tolkova, Elena

    determines the accuracy of any forecast of the future tsunami evolution. A tsunami wave in the open ocean isEOF analysis of a time series with application to tsunami detection Elena Tolkova a, a. Decomposition of a tsunami buoy record in a functional space of tidal EOFs presents an efficient tool

  11. Geologic flow characterization using tracer techniques

    SciTech Connect (OSTI)

    Klett, R. D.; Tyner, C. E.; Hertel, Jr., E. S.

    1981-04-01T23:59:59.000Z

    A new tracer flow-test system has been developed for in situ characterization of geologic formations. This report describes two sets of test equipment: one portable and one for testing in deep formations. Equations are derived for in situ detector calibration, raw data reduction, and flow logging. Data analysis techniques are presented for computing porosity and permeability in unconfined isotropic media, and porosity, permeability and fracture characteristics in media with confined or unconfined two-dimensional flow. The effects of tracer pulse spreading due to divergence, dispersion, and porous formations are also included.

  12. Elbow mass flow meter

    DOE Patents [OSTI]

    McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

    1994-01-01T23:59:59.000Z

    Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

  13. Low differential pressure and multiphase flow measurements by means of differential pressure devices

    E-Print Network [OSTI]

    Justo, Hernandez Ruiz,

    2004-11-15T23:59:59.000Z

    performance in the gas mass flow rate estimation was exhibited by the slotted and standard plates for the air-water flow, while poor results were obtained for the air-oil and air-water oil flows. The performance of all the flow meter tested in the analysis...

  14. An Evidence-Based Evaluation of the Cumulative Effects of Tidal Freshwater and Estuarine Ecosystem Restoration on Endangered Juvenile Salmon in the Columbia River: Final Report

    SciTech Connect (OSTI)

    Diefenderfer, Heida L.; Johnson, Gary E.; Thom, Ronald M.; Borde, Amy B.; Woodley, Christa M.; Weitkamp, Laurie A.; Buenau, Kate E.; Kropp, Roy K.

    2013-12-01T23:59:59.000Z

    The listing of 13 salmon and steelhead stocks in the Columbia River basin (hereafter collectively referred to as “salmon”) under the Endangered Species Act of 1973, as amended, has stimulated tidal wetland restoration in the lower 235 kilometers of the Columbia River and estuary for juvenile salmon habitat functions. The purpose of the research reported herein was to evaluate the effect on listed salmon of the restoration effort currently being conducted under the auspices of the federal Columbia Estuary Ecosystem Restoration Program (CEERP). Linking changes in the quality and landscape pattern of tidal wetlands in the lower Columbia River and estuary (LCRE) to salmon recovery is a complex problem because of the characteristics of the ecosystem, the salmon, the restoration actions, and available sampling technologies. Therefore, we designed an evidence-based approach to develop, synthesize, and evaluate information to determine early-stage (~10 years) outcomes of the CEERP. We developed an ecosystem conceptual model and from that, a primary hypothesis that habitat restoration activities in the LCRE have a cumulative beneficial effect on juvenile salmon. There are two necessary conditions of the hypothesis: • habitat-based indicators of ecosystem controlling factors, processes, and structures show positive effects from restoration actions, and • fish-based indicators of ecosystem processes and functions show positive effects from restoration actions and habitats undergoing restoration. Our evidence-based approach to evaluate the primary hypothesis incorporated seven lines of evidence, most of which are drawn from the LCRE. The lines of evidence are spatial and temporal synergies, cumulative net ecosystem improvement, estuary-wide meta-analysis, offsite benefits to juvenile salmon, landscape condition evaluation, and evidence-based scoring of global literature. The general methods we used to develop information for the lines of evidence included field measurements, data analyses, modeling, meta-analysis, and reanalysis of previously collected data sets. We identified a set of 12 ancillary hypotheses regarding habitat and salmon response. Each ancillary hypothesis states that the response metric will trend toward conditions at relatively undisturbed reference sites. We synthesized the evidence for and against the two necessary conditions by using eleven causal criteria: strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, analogy, complete exposure pathway, and predictive performance. Our final evaluation included cumulative effects assessment because restoration is occurring at multiple sites and the collective effect is important to salmon recovery. We concluded that all five lines of evidence from the LCRE indicated positive habitat-based and fish-based responses to the restoration performed under the CEERP, although tide gate replacements on small sloughs were an exception. Our analyses suggested that hydrologic reconnections restore access for fish to move into a site to find prey produced there. Reconnections also restore the potential for the flux of prey from the site to the main stem river, where our data show that they are consumed by salmon. We infer that LCRE ecosystem restoration supports increased juvenile salmon growth and enhanced fitness (condition), thereby potentially improving survival rates during the early ocean stage.

  15. Mon. Not. R. Astron. Soc. 391, 237245 (2008) doi:10.1111/j.1365-2966.2008.13868.x Tidal heating of terrestrial extrasolar planets and implications for their

    E-Print Network [OSTI]

    Barnes, Rory

    these issues, we model the tidal heating and evolution of hypothetical extrasolar terrestrial planets, Greenberg & Barnes 2008b). If such a planet is on an eccentric orbit, the dissipation of tidal energy within extrasolar planets are observed to be larger than theoretical modelling predicts (e.g. Bodenheimer, E

  16. Lateral flow strip assay

    DOE Patents [OSTI]

    Miles, Robin R. (Danville, CA); Benett, William J. (Livermore, CA); Coleman, Matthew A. (Oakland, CA); Pearson, Francesca S. (Livermore, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

    2011-03-08T23:59:59.000Z

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  17. Preliminary Screening Analysis for the Environmental Risk Evaluation System: Task 2.1.1: Evaluating Effects of Stressors – Fiscal Year 2010 Progress Report: Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.

    2010-11-15T23:59:59.000Z

    Possible environmental effects of marine and hydrokinetic (MHK) energy development are not well understood, and yet regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term effects. An understanding of risk associated with likely interactions between MHK installations and aquatic receptors, including animals, habitats, and ecosystems, can help reduce the level of uncertainty and focus regulatory actions and scientific studies on interactions of most concern. As a first step in developing the Pacific Northwest National Laboratory (PNNL) Environmental Risk Evaluation System (ERES), PNNL scientists conducted a preliminary risk screening analysis on three initial MHK cases - a tidal project in Puget Sound using Open Hydro turbines, a wave project off the coast of Oregon using Ocean Power Technologies point attenuator buoys, and a riverine current project in the Mississippi River using Free Flow turbines. Through an iterative process, the screening analysis revealed that top-tier stressors in all three cases were the effects of the dynamic physical presence of the device (e.g., strike), accidents, and effects of the static physical presence of the device (e.g., habitat alteration). Receptor interactions with these stressors at the four highest tiers of risk were dominated by marine mammals (cetaceans and pinnipeds) and birds (diving and non-diving); only the riverine case (Free Flow) included different receptors in the third tier (fish) and the fourth tier (benthic invertebrates). Although this screening analysis provides a preliminary analysis of vulnerability of environmental receptors to stressors associated with MHK installations, probability analysis, especially of risk associated with chemical toxicity and accidents such as oil spills or lost gear, will be necessary to further understand high-priority risks. Subject matter expert review of this process and results is required and is planned for the first quarter of FY11. Once expert review is finalized, the screening analysis phase of ERES will be complete.

  18. Nuclear-Coupled Flow Instabilities and Their Effects on Dryout

    SciTech Connect (OSTI)

    M. Ishii; X. Sunn; S. Kuran

    2004-09-27T23:59:59.000Z

    Nuclear-coupled flow/power oscillations in boiling water reactors (BWRs) are investigated experimentally and analytically. A detailed literature survey is performed to identify and classify instabilities in two-phase flow systems. The classification and the identification of the leading physical mechanisms of the two-phase flow instabilities are important to propose appropriate analytical models and scaling criteria for simulation. For the purpose of scaling and the analysis of the nonlinear aspects of the coupled flow/power oscillations, an extensive analytical modeling strategy is developed and used to derive both frequency and time domain analysis tools.

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

    E-Print Network [OSTI]

    Nicolau del Roure, Francisco

    2009-06-02T23:59:59.000Z

    of the inlet. b) Longitudinal position of the center of the main vortex starting from the edge of the barrier island. c) Lateral position of the center of the main vortex starting from the edge of the barrier island. d) Circulation around the main vortex... island. d) Circulation around the main vortex. e) Maximum vorticity in the main vortex. f) Equivalent diameter of the main vortex. g) Upwelling flowing from the main vortex. ...........................................34 Figure 11 Life-history Type I...

  20. Field Test of a DHW Distribution System: Temperature and Flow Analyses (Presentation)

    SciTech Connect (OSTI)

    Barley, C. D.; Hendron, B.; Magnusson, L.

    2010-05-13T23:59:59.000Z

    This presentation discusses a field test of a DHW distribution system in an occupied townhome. It includes measured fixture flows and temperatures, a tested recirculation system, evaluated disaggregation of flow by measured temperatures, Aquacraft Trace Wizard analysis, and comparison.