National Library of Energy BETA

Sample records for tidal wave current

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

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

    and In-Stream Hydrokinetic Power | Department of Energy 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, and In-Stream Hydrokinetic Power Assessment of Projected Life-Cycle Costs for Wave, Tidal, Ocean Current, and In-Stream Hydrokinetic Power 16_life_revision_previsic_update.ppt (2.64 MB) More Documents & Publications 2014 Water Power Program Peer Review

  2. 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...

  3. Energy Department Announces $8 Million to Develop Advanced Components for Wave, Tidal, and Current Energy Systems

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Energy Department today announced $8 million in available funding to spur innovation in next-generation marine and hydrokinetic control and component technologies. In the United States, waves, tides, and ocean currents represent a largely untapped renewable energy resource that could provide clean, affordable energy to homes and businesses across the country's coastal regions.

  4. 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, ...

  5. European Wave and Tidal Energy Conference

    Broader source: Energy.gov [DOE]

    The European Wave and Tidal Energy Conference (EWTEC) series are international, technical and scientific conferences, focussed on ocean renewable energy and widely respected for their commitment to...

  6. MHK Technologies/Uldolmok Pilot Tidal Current Power Plant | Open...

    Open Energy Info (EERE)

    Uldolmok Pilot Tidal Current Power Plant < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Uldolmok Pilot Tidal Current Power Plant.jpg...

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

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

    Department of Energy into Wave and Tidal Ocean Power: 15% Water Power by 2030 Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030 January 27, 2012 - 11:30am Addthis A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams. The East Coast, as shown above, has strong tides that could be tapped to produce energy. | Photo courtesy of Georgia Institute of Technology A map generated by Georgia Tech's tidal energy resource database

  8. Energy Department Invests $16 Million to Harness Wave and Tidal...

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

    Together, these projects will increase the power production and reliability of wave and tidal devices and help gather valuable data on how deployed devices interact with the ...

  9. Tidal & Current Modeling Development and Validation

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

    Tidal & Current Modeling Development and Validation - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste

  10. Status of Wave and Tidal Power Technologies for the United States

    SciTech Connect (OSTI)

    Musial, W.

    2008-08-01

    This paper presents the status of marine applications for renewable energy as of 2008 from a U.S. perspective. Technologies examined include wave, tidal, and ocean current energy extraction devices.

  11. The environmental interactions of tidal and wave energy generation devices

    SciTech Connect (OSTI)

    Frid, Chris; Andonegi, Eider; Judd, Adrian; Rihan, Dominic; Rogers, Stuart I.; Kenchington, Ellen

    2012-01-15

    Global energy demand continues to grow and tidal and wave energy generation devices can provide a significant source of renewable energy. Technological developments in offshore engineering and the rising cost of traditional energy means that offshore energy resources will be economic in the next few years. While there is now a growing body of data on the ecological impacts of offshore wind farms, the scientific basis on which to make informed decisions about the environmental effects of other offshore energy developments is lacking. Tidal barrages have the potential to cause significant ecological impacts particularly on bird feeding areas when they are constructed at coastal estuaries or bays. Offshore tidal stream energy and wave energy collectors offer the scope for developments at varying scales. They also have the potential to alter habitats. A diversity of designs exist, including floating, mid-water column and seabed mounted devices, with a variety of moving-part configurations resulting in a unique complex of potential environmental effects for each device type, which are discussed to the extent possible. - Highlights: Black-Right-Pointing-Pointer We review the environmental impacts of tidal barrages and fences, tidal stream farms and wave energy capture devices. Black-Right-Pointing-Pointer Impacts on habitats, species and the water column, and effects of noise and electromagnetic fields are considered. Black-Right-Pointing-Pointer Tidal barrages can cause significant impacts on bird feeding areas when constructed at coastal estuaries or bays. Black-Right-Pointing-Pointer Wave energy collectors can alter water column and sea bed habitats locally and over large distances.

  12. Energy Department Awards More Than $20 Million for Wave and Tidal Energy

    Energy Savers [EERE]

    Projects | Department of Energy More Than $20 Million for Wave and Tidal Energy Projects Energy Department Awards More Than $20 Million for Wave and Tidal Energy Projects August 30, 2016 - 1:15pm Addthis The Energy Department today announced 10 organizations selected to receive more than $20 million in funding for new research, development, and demonstration projects that advance and monitor marine and hydrokinetic (MHK) energy systems, which generate electricity from ocean waves and tidal

  13. Ocean current wave interaction study

    SciTech Connect (OSTI)

    Hayes, J.G.

    1980-09-20

    A numerical model has been developed to incorporate refraction of ocean surface gravity waves by major ocean currents. The model is initialized with directional wave spectra and verified with aircraft synthetic aperture radar X band spectra, laser profilometer spectra, and pitch and roll buoy data. Data collected during the Marineland test experiment are used as surface truth observations for the wave-current study. Evidence of Gulf Stream refraction and trapping of surface waves as well as caustics in the current is shown and modeled assuming a nonuniform Gulf Stream distribution. Frequency and directional resolution of the wave spectral distribution and the current refraction patterns illustrates the need for further study of ocean current-wave interaction in wave refraction studies.

  14. Tidal | OpenEI Community

    Open Energy Info (EERE)

    Submitted by Ocop(5) Member 15 July, 2014 - 07:07 MHK LCOE Reporting Guidance Draft Cost Current DOE LCOE numerical modeling Performance Tidal Wave To normalize competing...

  15. High-resolution velocimetry in energetic tidal currents using a convergent-beam acoustic Doppler profiler

    SciTech Connect (OSTI)

    Sellar, Brian; Harding, Samuel F.; Richmond, Marshall C.

    2015-07-16

    An array of convergent acoustic Doppler velocimeters has been developed and tested for the high resolution measurement of three-dimensional tidal flow velocities in an energetic tidal site. This configuration has been developed to increase spatial resolution of velocity measurements in comparison to conventional acoustic Doppler profilers (ADPs) which characteristically use diverging acoustic beams emanating from a single instrument. This is achieved using converging acoustic beams with a sample volume at the focal point of 0.03 m3. The array is also able to simultaneously measure three-dimensional velocity components in a profile throughout the water column, and as such is referred to herein as a converging-beam acoustic Doppler profiler (CADP). Mid-depth profiling is achieved through integration of the sensor platform with the operational Alstom 1MW DeepGen-IV Tidal Turbine. This proof-of-concept paper outlines system configuration and comparison to measurements provided by co-installed reference instrumentation. Comparison of CADP to standard ADP velocity measurements reveals a mean difference of 8 mm/s, standard deviation of 18 mm/s, and order-of-magnitude reduction in realizable length-scale. CADP focal point measurements compared to a proximal single-beam reference show peak cross-correlation coefficient of 0.96 over 4.0 s averaging period and a 47% reduction in Doppler noise. The dual functionality of the CADP as a profiling instrument with a high resolution focal point make this configuration a unique and valuable advancement in underwater velocimetry enabling improved turbulence, resource and structural loading quantification and validation of numerical simulations. Alternative modes of operation have been implemented including noise-reducing bi-static sampling. Since waves are simultaneously measured it is expected that derivatives of this system will be a powerful tool in wave-current interaction studies.

  16. Gravitational waves from the collision of tidally disrupted stars with massive black holes

    SciTech Connect (OSTI)

    East, William E.

    2014-11-10

    We use simulations of hydrodynamics coupled with full general relativity to investigate the gravitational waves produced by a star colliding with a massive black hole when the star's tidal disruption radius lies far outside of the black hole horizon. We consider both main-sequence and white-dwarf compaction stars, and nonspinning black holes, as well as those with near-extremal spin. We study the regime in between where the star can be accurately modeled by a point particle, and where tidal effects completely suppress the gravitational wave signal. We find that nonnegligible gravitational waves can be produced even when the star is strongly affected by tidal forces, as well as when it collides with large angular momentum. We discuss the implications that these results have for the potential observation of gravitational waves from these sources with future detectors.

  17. Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska final report

    SciTech Connect (OSTI)

    Wright, Bruce Albert

    2014-05-07

    The Aleutian Pribilof Islands Association was awarded a U.S. Department of Energy Tribal Energy Program grant (DE-EE0005624) for the Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska (Project). The goal of the Project was to perform a feasibility study to determine if a tidal energy project would be a viable means to generate electricity and heat to meet long-term fossil fuel use reduction goals, specifically to produce at least 30% of the electrical and heating needs of the tribally-owned buildings in False Pass. The Project Team included the Aleut Region organizations comprised of the Aleutian Pribilof Island Association (APIA), and Aleutian Pribilof Island Community Development Association (APICDA); the University of Alaska Anchorage, ORPC Alaska a wholly-owned subsidiary of Ocean Renewable Power Company (ORPC), City of False Pass, Benthic GeoScience, and the National Renewable Energy Laboratory (NREL). The following Project objectives were completed: collected existing bathymetric, tidal, and ocean current data to develop a basic model of current circulation at False Pass, measured current velocities at two sites for a full lunar cycle to establish the viability of the current resource, collected data on transmission infrastructure, electrical loads, and electrical generation at False Pass, performed economic analysis based on current costs of energy and amount of energy anticipated from and costs associated with the tidal energy project conceptual design and scoped environmental issues. Utilizing circulation modeling, the Project Team identified two target sites with strong potential for robust tidal energy resources in Isanotski Strait and another nearer the City of False Pass. In addition, the Project Team completed a survey of the electrical infrastructure, which identified likely sites of interconnection and clarified required transmission distances from the tidal energy resources. Based on resource and electrical data

  18. Hydropower, Wave and Tidal Technologies Available for Licensing - Energy

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

    Hydropower | Department of Energy Hydropower Vision: New Report Highlights Future Pathways for U.S. Hydropower Hydropower Vision: New Report Highlights Future Pathways for U.S. Hydropower July 26, 2016 - 3:00pm Addthis Hydropower Vision: New Report Highlights Future Pathways for U.S. Hydropower Jose Zayas Jose Zayas Wind Energy Technologies Office Director Hydropower has been around for more than a century, and is currently the nation's largest source of clean, domestic, renewable

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

    SciTech Connect (OSTI)

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

    2011-10-01

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

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

    SciTech Connect (OSTI)

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

    2014-04-30

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

  1. Wave | OpenEI Community

    Open Energy Info (EERE)

    Submitted by Ocop(5) Member 15 July, 2014 - 07:07 MHK LCOE Reporting Guidance Draft Cost Current DOE LCOE numerical modeling Performance Tidal Wave To normalize competing...

  2. Current | OpenEI Community

    Open Energy Info (EERE)

    Submitted by Ocop(5) Member 15 July, 2014 - 07:07 MHK LCOE Reporting Guidance Draft Cost Current DOE LCOE numerical modeling Performance Tidal Wave To normalize competing...

  3. Fast wave current drive in DEMO

    SciTech Connect (OSTI)

    Lerche, E.; Van Eestera, D.; Messiaen, A.; Collaboration: EFDA-PPPT Contributors

    2014-02-12

    The ability to non-inductively drive a large fraction of the toroidal plasma current in magnetically confined plasmas is an essential requirement for steady state fusion reactors such as DEMO. Besides neutral beam injection (NBI), electron-cyclotron resonance heating (ECRH) and lower hybrid wave heating (LH), ion-cyclotron resonance heating (ICRH) is a promising candidate to drive current, in particular at the high temperatures expected in fusion plasmas. In this paper, the current drive (CD) efficiencies calculated with coupled ICRF wave / CD numerical codes for the DEMO-1 design case (R{sub 0}=9m, B{sub 0}=6.8T, a{sub p}=2.25m) [1] are presented. It will be shown that although promising CD efficiencies can be obtained in the usual ICRF frequency domain (20-100MHz) by shifting the dominant ion-cyclotron absorption layers to the high-field side, operation at higher frequencies (100-300MHz) has a stronger CD potential, provided the parasitic RF power absorption of the alpha particles can be minimized.

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

    SciTech Connect (OSTI)

    Neary, Vincent S; Gunawan, Budi

    2011-09-01

    In this report, existing data collection techniques and protocols for characterizing open channel flows are reviewed and refined to further address the needs of the MHK industry. The report provides an overview of the hydrodynamics of river and tidal channels, and the working principles of modern acoustic instrumentation, including best practices in remote sensing methods that can be applied to hydrokinetic energy site characterization. Emphasis is placed upon acoustic Doppler velocimeter (ADV) and acoustic-Doppler current profiler (ADCP) instruments, as these represent the most practical and economical tools for use in the MHK industry. Incorporating the best practices as found in the literature, including the parameters to be measured, the instruments to be deployed, the instrument deployment strategy, and data post-processing techniques. The data collected from this procedure aims to inform the hydro-mechanical design of MHK systems with respect to energy generation and structural loading, as well as provide reference hydrodynamics for environmental impact studies. The standard metrics and protocols defined herein can be utilized to guide field experiments with MHK systems.

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

    DOE Patents [OSTI]

    Gorlov, Alexander M.

    1991-01-01

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

  6. Renewables in Alaska Native Villages: Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, Alaska

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

    Funding: Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, AK Bruce Wright, APIA Monty Worthington, ORPC Wright, B. A., J. W. Short, T. J. Weingartner and P. J. Anderson. 2000. The Gulf of Alaska.. Pp 373-384 in Sheppard, C. R. C., ed., Seas at the Millennium: An Environmental, Evaluation Volume I Regional Chapters: Europe, The Americas and Wes Africa. Pergammon Press, Elsevier, Amsterdam. Aleutian Pribilof Islands Regional Energy Summit April 24-25, 2010 Anchorage,

  7. Penetration of lower hybrid current drive waves in tokamaks

    SciTech Connect (OSTI)

    Horton, W.; Aix-Marseille University, 58, Bd Charles Livon, 13284 Marseille ; Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X.

    2013-11-15

    Lower hybrid (LH) ray propagation in toroidal plasma is shown to be controlled by combination of the azimuthal spectrum launched by the antenna, the poloidal variation of the magnetic field, and the scattering of the waves by the drift wave fluctuations. The width of the poloidal and radial radio frequency wave spectrum increases rapidly as the rays penetrate into higher density and scatter from the drift waves. The electron temperature gradient (ETG) spectrum is particularly effective in scattering the LH waves due to its comparable wavelengths and phase velocities. ETG turbulence is also driven by the radial gradient of the electron current profile giving rise to an anomalous viscosity spreading the LH driven plasma currents. The LH wave scattering is derived from a Fokker-Planck equation for the distribution of the ray trajectories with diffusivities derived from the drift wave fluctuations. The condition for chaotic diffusion for the rays is derived. The evolution of the poloidal and radial mode number spectrum of the lower hybrid waves are both on the antenna spectrum and the spectrum of the drift waves. Antennas launching higher poloidal mode number spectra drive off-axis current density profiles producing negative central shear [RS] plasmas with improved thermal confinement from ETG transport. Core plasma current drive requires antennas with low azimuthal mode spectra peaked at m = 0 azimuthal mode numbers.

  8. Energy Department Awards More Than $20 Million for Wave and Tidal...

    Energy Savers [EERE]

    Dresser-Rand of Wellsville, New York, will integrate a one-megawatt air-turbine power system into the OceanEnergy oscillating water column wave energy device, doubling the power ...

  9. HEATING AND CURRENT DRIVE IN NSTX WITH ELECTRON BERNSTEIN WAVES AND HIGH HARMONIC FAST WAVES

    SciTech Connect (OSTI)

    Ram, Abhay K

    2010-06-14

    A suitable theoretical and computational framework for studying heating and current drive by electron Bernstein waves in the National Spherical Torus Experiment has been developed. This framework can also be used to study heating and current drive by electron Bernstein waves in spherical tori and other magnetic confinement devices. It is also useful in studying the propagation and damping of electron cyclotron waves in the International Thermonuclear Experimental Reactor

  10. 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.

    2011-10-01

    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.

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

    SciTech Connect (OSTI)

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

    2011-01-01

    This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines (HATTs). First, an HATT blade was designed using the blade element momentum method in conjunction with a genetic optimization algorithm. Several unstructured computational grids were generated using this blade geometry and steady CFD simulations were used to perform a grid resolution study. Transient simulations were then performed to determine the effect of time-dependent flow phenomena and the size of the computational timestep on the numerical solution. 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.

  12. Three-dimensional structures of equatorial waves and the resulting super-rotation in the atmosphere of a tidally locked hot Jupiter

    SciTech Connect (OSTI)

    Tsai, Shang-Min; Gu, Pin-Gao; Dobbs-Dixon, Ian

    2014-10-01

    Three-dimensional (3D) equatorial trapped waves excited by stellar isolation and the resulting equatorial super-rotating jet in a vertical stratified atmosphere of a tidally locked hot Jupiter are investigated. Taking the hot Jupiter HD 189733b as a fiducial example, we analytically solve linear equations subject to stationary stellar heating with a uniform zonal-mean flow included. We also extract wave information in the final equilibrium state of the atmosphere from our radiative hydrodynamical simulation for HD 189733b. Our analytic wave solutions are able to qualitatively explain the 3D simulation results. Apart from previous wave studies, investigating the vertical structure of waves allows us to explore new wave features such as the wavefronts tilts related to the Rossby-wave resonance as well as dispersive equatorial waves. We also attempt to apply our linear wave analysis to explain some numerical features associated with the equatorial jet development seen in the general circulation model by Showman and Polvani. During the spin-up phase of the equatorial jet, the acceleration of the jet can be in principle boosted by the Rossby-wave resonance. However, we also find that as the jet speed increases, the Rossby-wave structure shifts eastward, while the Kelvin-wave structure remains approximately stationary, leading to the decline of the acceleration rate. Our analytic model of jet evolution implies that there exists only one stable equilibrium state of the atmosphere, possibly implying that the final state of the atmosphere is independent of initial conditions in the linear regime. Limitations of our linear model and future improvements are also discussed.

  13. Tidal Energy Basics | Department of Energy

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

    ... Map Reveals U.S. Tidal Energy Resources Artist rendering of Ocean Power Technologies' proposed wave park off the coast of Oregon. | Photo courtesy of Ocean Power Technologies. ...

  14. Wave Energy Converter (WEC) Array Effects on Wave Current and Sediment Circulation: Monterey Bay CA.

    SciTech Connect (OSTI)

    Roberts, Jesse D.; Jones, Craig; Magalen, Jason

    2014-09-01

    The goal s of this study were to develop tools to quantitatively characterize environments where wave energy converter ( WEC ) devices may be installed and to assess e ffects on hydrodynamics and lo cal sediment transport. A large hypothetical WEC array was investigated using wave, hydrodynamic, and sediment transport models and site - specific average and storm conditions as input. The results indicated that there were significant changes in sediment s izes adjacent to and in the lee of the WEC array due to reduced wave energy. The circulation in the lee of the array was also altered; more intense onshore currents were generated in the lee of the WECs . In general, the storm case and the average case show ed the same qualitative patterns suggesting that these trends would be maintained throughout the year. The framework developed here can be used to design more efficient arrays while minimizing impacts on nearshore environmen ts.

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

    SciTech Connect (OSTI)

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

    2012-07-01

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

  16. tidal turbines

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

    tidal turbines - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear

  17. List of Tidal Energy Incentives | Open Energy Information

    Open Energy Info (EERE)

    Coal with CCS Concentrating Solar Power Energy Storage Fuel Cells Geothermal Electric Natural Gas Nuclear Tidal Energy Wave Energy Wind energy BiomassBiogas Hydroelectric...

  18. Tidal Energy Resource Assessment | Department of Energy

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

    Tidal Energy Resource Assessment Tidal Energy Resource Assessment Tidal Energy Resource Assessment 51_tidalresource_gtrc_haas.ppt (8.56 MB) More Documents & Publications Ocean current resource assessment Free Flow Energy (TRL 1 2 3 Component) - Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion Effects on the Physical Environment (Hydrodynamics, and Water Quality Food Web)

  19. MHK technology developments include current

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

    technology developments include current energy conversion (CEC) devices, for example, hydrokinetic turbines that extract power from water currents (riverine, tidal, and ocean) and wave energy conversion (WEC) devices that extract power from wave motion. Sandia's MHK research leverages decades of experience in engineering, design, and analysis of wind power technologies, and its vast research complex, including high- performance computing (HPC), advanced materials and coatings, nondestructive

  20. Modeling of high harmonic fast wave current drive on EAST tokamak

    SciTech Connect (OSTI)

    Li, J. C.; Gong, X. Y. Li, F. Y.; Dong, J. Q.; Gao, Q. D.; Zhang, N.

    2015-10-15

    High harmonic fast waves (HHFW) are among the candidates for non-inductive current drive (CD), which is essential for long-pulse or steady-state operation of tokamaks. Current driven with HHFW in EAST tokamak plasmas is numerically studied. The HHFW CD efficiency is found to increase non-monotonically with the wave frequency, and this phenomenon is attributed to the multi-pass absorption of HHFW. The sensitivity of CD efficiency to the value of the parallel refraction index of the launched wave is confirmed. The quasilinear effects, assessed as significant in HHFW current drive with the GENRAY/CQL3D package, cause a significant increase in CD efficiency as RF power is increased, which is very different from helicon current drive. Simulations for a range of toroidal dc electric fields, in combination with a range of fast wave powers, are also presented and indicate that the presence of the DC field can also enhance the CD efficiency.

  1. Dependence of synergy current driven by lower hybrid wave and electron cyclotron wave on the frequency and parallel refractive index of electron cyclotron wave for Tokamaks

    SciTech Connect (OSTI)

    Huang, J.; Chen, S. Y. Tang, C. J.; Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064

    2014-01-15

    The physical mechanism of the synergy current driven by lower hybrid wave (LHW) and electron cyclotron wave (ECW) in tokamaks is investigated using theoretical analysis and simulation methods in the present paper. Research shows that the synergy relationship between the two waves in velocity space strongly depends on the frequency ω and parallel refractive index N{sub //} of ECW. For a given spectrum of LHW, the parameter range of ECW, in which the synergy current exists, can be predicted by theoretical analysis, and these results are consistent with the simulation results. It is shown that the synergy effect is mainly caused by the electrons accelerated by both ECW and LHW, and the acceleration of these electrons requires that there is overlap of the resonance regions of the two waves in velocity space.

  2. New Interactive Map Reveals U.S. Tidal Energy Resources | Department of

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

    Energy Interactive Map Reveals U.S. Tidal Energy Resources New Interactive Map Reveals U.S. Tidal Energy Resources July 7, 2011 - 10:50am Addthis A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams | Source: Georgia Institute of Technology A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams | Source: Georgia Institute of Technology Michael Reed Michael Reed Director, Technical and

  3. Dynamic control of spin wave spectra using spin-polarized currents

    SciTech Connect (OSTI)

    Wang, Qi; Zhang, Huaiwu Tang, Xiaoli; Bai, Feiming; Zhong, Zhiyong; Fangohr, Hans

    2014-09-15

    We describe a method of controlling the spin wave spectra dynamically in a uniform nanostripe waveguide through spin-polarized currents. A stable periodic magnetization structure is observed when the current flows vertically through the center of nanostripe waveguide. After being excited, the spin wave is transmitted at the sides of the waveguide. Numerical simulations of spin-wave transmission and dispersion curves reveal a single, pronounced band gap. Moreover, the periodic magnetization structure can be turned on and off by the spin-polarized current. The switching process from full rejection to full transmission takes place within less than 3?ns. Thus, this type magnonic waveguide can be utilized for low-dissipation spin wave based filters.

  4. DOE Science Showcase - Tidal Energy | OSTI, US Dept of Energy...

    Office of Scientific and Technical Information (OSTI)

    DOE Science Showcase - Tidal Energy Point absorbers generate electricity by converting the energy in waves using a float that rides the waves and is attached to a moored conversion ...

  5. Co-counter asymmetry in fast wave heating and current drive and profile control in NSTX

    SciTech Connect (OSTI)

    Jaeger, E.F.; Carter, M.D.; Berry, L.A.; Batchelor, D.B.; Ryan, P.M.; Forest, C.B.; Weitzner, H.; Majeski, R.

    1997-08-01

    In this paper, full-wave ICRF coupling models are applied to understand the difference in plasma response when antenna arrays are phased to drive currents co and counter to the plasma current. The source of this difference lies in the natural up-down asymmetry of the antenna`s radiated power spectrum caused by Hall currents. When a poloidal field is applied, this up-down asymmetry acquires a toroidal component. The result is that plasma absorption (i.e., antenna loading) is shifted or skewed toward the co-current drive direction, independent of the direction of the magnetic field. When waves are launched to drive current counter to the plasma current, electron heating and current profiles are more peaked on axis, and this peaking becomes more pronounced at lower toroidal magnetic fields.

  6. Near-surface current meter array measurements of internal gravity waves

    SciTech Connect (OSTI)

    Jones, H.B.E.

    1994-11-15

    We have developed various processing algorithms used to estimate the wave forms produced by hydrodynamic Internal Waves. Furthermore, the estimated Internal Waves are used to calculate the Modulation Transfer Function (MTF) which relates the current and strain rate subsurface fields to surface scattering phenomenon imaged by radar. Following a brief discussion of LLNL`s measurement platform (a 10 sensor current meter array) we described the generation of representative current and strain rate space-time images from measured or simulated data. Then, we present how our simulation capability highlighted limitations in estimating strain rate. These limitations spurred the application of beamforming techniques to enhance our estimates, albeit at the expense of collapsing our space-time images to 1-D estimates. Finally, we discuss progress with regard to processing the current meter array data captured during the recent Loch Linnhe field trials.

  7. Tidal Electric | Open Energy Information

    Open Energy Info (EERE)

    Tidal Electric Place: London, Greater London, United Kingdom Zip: SW19 8UY Product: Developed a technology named 'tidal lagoons' to build tidal electric projects. Coordinates:...

  8. Wave–current interaction in the presence of a three-dimensional bathymetry: Deep water wave focusing in opposing current conditions

    SciTech Connect (OSTI)

    Rey, V. Charland, J. Touboul, J.

    2014-09-15

    Large scale experiments were carried out in the Ocean Engineering Basin FIRST, France. A tri-dimensional bathymetry consisting of two symmetrical submerged mounds was displayed on the flat bed on both sides of the basin. Regular waves of frequency corresponding to deep water conditions above the bathymetry were generated in opposing current conditions. A strong tri-dimensional behaviour is observed for the wave amplitude, leading to a strong focusing (up to twice the incident amplitude) of the wave energy towards the central deeper zone. This amplification cannot be ascribed to the increase of the current intensity in the main wave direction, nor to a current gradient normally to the wave direction. A wave phase gradient, normal to its main direction, is observed up-wave (or downstream) the mounds. This phase lag depends on the wave amplitude, it is the higher for the moderate amplitude case. The experimental data are compared with calculations of a refraction-diffraction model assuming a depth-averaged current. If the model qualitatively predicts the wave amplification in the centerline of the basin, discrepancies are observed in the vicinity of the depth changes. The observed mean current vertical profile shape is then supposed to play a significant role in the wave focusing, especially near the steep slopes down-stream the mounds. In addition, the waves are found to modify substantially both horizontal and vertical current fields.

  9. Numerical studies of electron cyclotron wave current drive on HL-2A tokamak

    SciTech Connect (OSTI)

    Li, J. C.; Gong, X. Y.; Dong, J. Q.; Song, S. D.; Gao, Q. D.; Zheng, P. W.; Du, D.

    2015-06-15

    The electron cyclotron wave (ECW) current drive (CD) for the HL-2A tokamak is investigated numerically with a new ray-tracing and Fokker-Planck code. The code is benchmarked with other well-tested linear and quasilinear codes and is then used to study the electron cyclotron current drive on the HL-2A tokamak. The wave propagation, power deposition, and driven-current profiles are presented. The effect of electron trapping is also assessed. It is found that quasilinear effects are negligible at the present ECW power levels and that when both waves are injected at an angle of 20° on the plasma equatorial plane, the CD efficiency for the HL-2A saturates at ∼0.029 × 10{sup 20 }A/W/m{sup 2} and ∼0.020 × 10{sup 20 }A/W/m{sup 2} for the 0.5 MW/68 GHz first harmonic ordinary (O1) and 1 MW/140 GHz second harmonic extraordinary (X2) modes, respectively. The effects of the plasma density, temperature, and wave-launching position on the driven current are also investigated analytically and numerically.

  10. Filamentation instability of current-driven dust ion-acoustic waves in a collisional dusty plasma

    SciTech Connect (OSTI)

    Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 19839-63113 (Iran, Islamic Republic of); Haghtalab, T.; Khorashadizadeh, S. M. [Physics Department, Birjand University, Birjand 97179-63384 (Iran, Islamic Republic of)

    2011-11-15

    A theoretical investigation has been made of the dust ion-acoustic filamentation instability in an unmagnetized current-driven dusty plasma by using the Lorentz transformation formulas. The effect of collision between the charged particles with neutrals and their thermal motion on this instability is considered. Developing the filamentation instability of the current-driven dust ion-acoustic wave allows us to determine the period and the establishment time of the filamentation structure and threshold for instability development.

  11. MHK Projects/Clarence Strait Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Project Country Australia Project Resource Click here Current Tidal Project Nearest Body of Water Clarence Strait Coordinates -12.083533792616, 131.04972839355 Project...

  12. MHK Technologies/KESC Tidal Generator | Open Energy Information

    Open Energy Info (EERE)

    Technology Resource Click here CurrentTidal Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 1-3: Discovery Concept Definition Early...

  13. DOE Science Showcase - Tidal Energy | OSTI, US Dept of Energy...

    Office of Scientific and Technical Information (OSTI)

    The Department of Energy's Water Power Program Tapping into Wave and Tidal Ocean Power: 15% Water Power by 2030, Energy.gov News Assessment of Energy Production Potential from ...

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

    Open Energy Info (EERE)

    Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgwindex.php?titleClarenceStrai...

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

    SciTech Connect (OSTI)

    Ibragimov, Ranis N.; Tartakovsky, Alexandre M.

    2014-10-29

    Efficiency of mixing, resulting from the reflection of an internal wave field imposed on the oscillatory background flow with a three-dimensional bottom topography, is investigated using a linear approximation. The radiating wave field is associated with the spectrum of the linear model, which consists of those mode numbers n and slope values α, for which the solution represents the internal waves of frequencies ω = nω0 radiating upwrad of the topography, where ω0 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, θ 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.

  16. Electron Bernstein wave-bootstrap current synergy in the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Harvey, R.W.; Taylor, G.

    2005-05-15

    Current driven by electron Bernstein waves (EBW) and by the electron bootstrap effect are calculated separately and concurrently with a kinetic code to determine the degree of synergy between them. A target {beta}=40% NSTX [M. Ono, S. Kaye, M. Peng et al., Proceedings of the 17th IAEA Fusion Energy Conference, edited by M. Spak (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135] plasma is examined. A simple bootstrap model in the collisional-quasilinear CQL3D Fokker-Planck code (National Technical Information Service document No. DE93002962) is used in these studies: the transiting electron distributions are connected in velocity space at the trapped-passing boundary to trapped-electron distributions that are displaced radially by a half-banana-width outwards/inwards for the co-passing/counter-passing regions. This model agrees well with standard bootstrap current calculations over the outer 60% of the plasma radius. Relatively small synergy net bootstrap current is obtained for EBW power up to 4 MW. Locally, bootstrap current density increases in proportion to increased plasma pressure, and this effect can significantly affect the radial profile of driven current.

  17. Collaborative research: Dynamics of electrostatic solitary waves and their effects on current layers

    SciTech Connect (OSTI)

    Chen, Li-Jen

    2014-04-18

    The project has accomplished the following achievements including the goals outlined in the original proposal. Generation and measurements of Debye-scale electron holes in laboratory: We have generated by beam injections electron solitary waves in the LAPD experiments. The measurements were made possible by the fabrication of the state-of-the-art microprobes at UCLA to measure Debye-scale electric fields [Chiang et al., 2011]. We obtained a result that challenged the state of knowledge about electron hole generation. We found that the electron holes were not due to two-stream instability, but generated by a current-driven instability that also generated whistler-mode waves [Lefebvre et al., 2011, 2010b]. Most of the grant supported a young research scientist Bertrand Lefebvre who led the dissemination of the laboratory experimental results. In addition to two publications, our work relevant to the laboratory experiments on electron holes has resulted in 7 invited talks [Chen, 2007, 2009; Pickett et al., 2009a; Lefebvre et al., 2010a; Pickett et al., 2010; Chen et al., 2011c, b] (including those given by the co-I Jolene Pickett) and 2 contributed talks [Lefebvre et al., 2009b, a]. Discovery of elecctron phase-space-hole structure in the reconnection electron layer: Our theoretical analyses and simulations under this project led to the discovery of an inversion electric field layer whose phase-space signature is an electron hole within the electron diffusion layer in 2D anti-parallel reconnection [Chen et al., 2011a]. We carried out particle tracing studies to understand the electron orbits that result in the phase-space hole structure. Most importantly, we showed that the current density in the electron layer is limited in collisionless reconnection with negligible guide field by the cyclotron turning of meandering electrons. Comparison of electrostatic solitary waves in current layers observed by Cluster and in LAPD: We compared the ESWs observed in a supersubstorm

  18. Microsoft Word - RM1_Tidal Turbine_NREL Bir, Lawson, Li_2011...

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

    OMAE2011-50063 STRUCTURAL DESIGN OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE COMPOSITE BLADE ABSTRACT This paper describes the structural design of a tidal turbine composite blade. ...

  19. The record of sea level rise by tidal sand bodies of the English Channel

    SciTech Connect (OSTI)

    Berne, S; Lericolais, G. (Ifremer, Plouzane, (France)); Lafont, F. (Universite d'Orsay (France))

    1990-05-01

    Improvements of very high resolution seismic reflection provide new information about internal structures of modern sand bodies. This allows us to reconstruct their recent history, which is related to the Holocene sea level rise. A major distinction is found between inner shelf sand bodies, dominated by autocyclic processes, and outer shelf sand bodies, where allocyclic processes are invoked to explain the apparent contradiction between internal structures and present-day dynamics. On the inner shelf, evidence of the migration of tidal dunes (sand waves) has been obtained by repeated surveys using accurate positioning systems. Major bounding surfaces are thought to result from the action of tidal current and/or from episodic storms. A rough estimation of the age of these sand bodies can be proposed. On the outer shelf, some dunes of the English Channel exhibit cross-beds indicative of a past net bed-load transport at the opposite of present days dynamics, inherited from different tidal conditions when sea level was between 20 and 40 m lower. Some large tidal sand banks (e.g., the Sark Bank near the Channel Islands) display a more complicated pattern. The upper part of the sand bank is the result of the migration of very large dunes climbing at positive angles, whereas the lower part shows major erosional surfaces, attributed to the action of storms during lower sea levels.

  20. Tidal energy site resource assessment in the East River tidal strait, near Roosevelt Island, New York, New York

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

    Gunawan, Budi; Neary, Vincent S.; Colby, Jonathan

    2014-06-22

    This study demonstrates a site resource assessment to examine the temporal variation of the mean current, turbulence intensities, and power densities for a tidal energy site in the East River tidal strait. These variables were derived from two-months of acoustic Doppler velocimeter (ADV) measurements at the design hub height of the Verdant Power Gen5 hydrokinetic turbine. The study site is a tidal strait that exhibits semi-diurnal tidal current characteristics, with a mean horizontal current speed of 1.4 m s-1, and turbulence intensity of 15% at a reference mean current of 2 m s-1. Flood and ebb flow directions are nearlymore » bi-directional, with higher current magnitude during flood tide, which skews the power production towards the flood tide period. The tidal hydrodynamics at the site are highly regular, as indicated by the tidal current time series that resembles a sinusoidal function. This study also shows that the theoretical force and power densities derived from the current measurements can significantly be influenced by the length of the time window used for averaging the current data. Furthermore, the theoretical power density at the site, derived from the current measurements, is one order of magnitude greater than that reported in the U.S. national resource assessment. As a result, this discrepancy highlights the importance of conducting site resource assessments based on measurements at the tidal energy converter device scale.« less

  1. Tidal energy site resource assessment in the East River tidal strait, near Roosevelt Island, New York, New York

    SciTech Connect (OSTI)

    Gunawan, Budi; Neary, Vincent S.; Colby, Jonathan

    2014-06-22

    This study demonstrates a site resource assessment to examine the temporal variation of the mean current, turbulence intensities, and power densities for a tidal energy site in the East River tidal strait. These variables were derived from two-months of acoustic Doppler velocimeter (ADV) measurements at the design hub height of the Verdant Power Gen5 hydrokinetic turbine. The study site is a tidal strait that exhibits semi-diurnal tidal current characteristics, with a mean horizontal current speed of 1.4 m s-1, and turbulence intensity of 15% at a reference mean current of 2 m s-1. Flood and ebb flow directions are nearly bi-directional, with higher current magnitude during flood tide, which skews the power production towards the flood tide period. The tidal hydrodynamics at the site are highly regular, as indicated by the tidal current time series that resembles a sinusoidal function. This study also shows that the theoretical force and power densities derived from the current measurements can significantly be influenced by the length of the time window used for averaging the current data. Furthermore, the theoretical power density at the site, derived from the current measurements, is one order of magnitude greater than that reported in the U.S. national resource assessment. As a result, this discrepancy highlights the importance of conducting site resource assessments based on measurements at the tidal energy converter device scale.

  2. TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING

    SciTech Connect (OSTI)

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

    2013-06-13

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

  3. Wave

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

    1 Summer 2001 Heat Wave This summer has proved to be downright hot in the Southern Great ... Not only is a summer heat wave uncomfortable, but it can also be ARM Facilities Newsletter ...

  4. Method for estimation of ocean current velocity from satellite images

    SciTech Connect (OSTI)

    Mollo-Christensen, E.; Cornillon, P.; Da S. Mascarenhas, A. Jr.

    1981-05-08

    Barotropic instability waves on a shear interface propagate at the average speed of the water on the two sides. Assuming the instability to be excited by tidal oscillations, the phase speed is the wavelength divided by the tidal period. If the water is at rest on one side of the shear layer the current speed on the other side can be calculated. This method, applied to the Gulf Stream beyond Cape Hatteras as seen in satellite images, gives estimates of current speed in general agreement with in situ observations.

  5. Surface acoustic wave amplification by direct current-voltage supplied to graphene film

    SciTech Connect (OSTI)

    Insepov, Z.; Emelin, E.; Kononenko, O.; Roshchupkin, D. V.; Tnyshtykbayev, K. B.; Baigarin, K. A.

    2015-01-12

    Using a high-resolution X-Ray diffraction measurement method, the surface acoustic wave (SAW) propagation in a graphene film on the surface of a Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} (CTGS) piezoelectric crystal was investigated, where an external current was driven across the graphene film. Here, we show that the application of the DC field leads to a significant enhancement of the SAW magnitude and, as a result, to amplification of the diffraction satellites. Amplification of 33.2 dB/cm for the satellite +1, and of 13.8 dB/cm for the satellite +2, at 471 MHz has been observed where the external DC voltage of +10 V was applied. Amplification of SAW occurs above a DC field much smaller than that of a system using bulk semiconductor. Theoretical estimates are in reasonable agreement with our measurements and analysis of experimental data for other materials.

  6. MHK Technologies/Sabella subsea tidal turbine | Open Energy Informatio...

    Open Energy Info (EERE)

    surface. These turbines are stabilised by gravity andor are anchored according to the nature of the seafloor. They are pre-orientated in the direction of the tidal currents, and...

  7. MHK Technologies/MORILD 2 Floating Tidal Power System | Open...

    Open Energy Info (EERE)

    based on the same principle as horizontal axis wind turbines. The plant has 4 two-blade underwater turbines and can utilize the energy potential in tidal and ocean currents....

  8. MHK Projects/Tidal Energy Device Evaluation Center TIDEC | Open...

    Open Energy Info (EERE)

    StateProvince Maine Project Country United States Project Resource Click here Current Tidal Coordinates 44.3879, -68.7998 Project Phase Phase 1 Device Nameplate Capacity (MW)...

  9. MHK Projects/Lubec Narrows Tidal | Open Energy Information

    Open Energy Info (EERE)

    Resource Click here Current Tidal Project Nearest Body of Water Lubec Narrows and Johnson Bay Coordinates 44.8652, -66.9828 Project Phase Phase 1 PermitLicense Buildout...

  10. Microsoft Word - RM1_Tidal Turbine_NREL Lawson, Li Y, Sale_2011...

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

    MODEL OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE ABSTRACT This paper describes the ... of the hydrodynamic forces on the turbine blade in comparison to the forces ...

  11. MHK Projects/Half Moon Cove Tidal Project | Open Energy Information

    Open Energy Info (EERE)

    Country United States Project Resource Click here Current Tidal Project Nearest Body of Water Passamaquoddy Bay Coordinates 44.9062, -66.99 Project Phase Phase 1 Project...

  12. MHK Projects/Central Cook Inlet Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Province Alaska Project Country United States Project Resource Click here Current Tidal Coordinates 59.9669, -152.226 Project Phase Phase 1 Main Overseeing Organization...

  13. Tidal & Current Modeling Development and Validation

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

    Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering ...

  14. Tidal Energy Research

    SciTech Connect (OSTI)

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

    2014-03-31

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

  15. TidalStream | Open Energy Information

    Open Energy Info (EERE)

    TidalStream Jump to: navigation, search Name: TidalStream Place: Southam, United Kingdom Zip: CV47 0HF Product: UK-based developer of platforms for tidal turbines. Coordinates:...

  16. Tidal Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    Limited Jump to: navigation, search Name: Tidal Energy Limited (TEL) Place: Cardiff, Wales, United Kingdom Zip: CF23 8RS Product: Tidal stream device developer. Coordinates:...

  17. Tocardo Tidal Energy Ltd | Open Energy Information

    Open Energy Info (EERE)

    Tocardo Tidal Energy Ltd Jump to: navigation, search Name: Tocardo Tidal Energy Ltd Address: De Weel 20 Place: Zijdewind Zip: 1736KB Region: Netherlands Sector: Marine and...

  18. NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

    SciTech Connect (OSTI)

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

    2012-01-01

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

  19. Ecological safety of tidal-power projects

    SciTech Connect (OSTI)

    Fedorov, M. P.; Shilin, M. B.

    2010-07-15

    The operating regime of tidal power plants requires ecological monitoring of their associated water area.

  20. Tidal Stream | Open Energy Information

    Open Energy Info (EERE)

    Stream Jump to: navigation, search Name: Tidal Stream Address: 76 Dukes Ave Place: London Zip: W4 2 AK Region: United Kingdom Sector: Marine and Hydrokinetic Phone Number: 01926...

  1. List of Wave Energy Incentives | Open Energy Information

    Open Energy Info (EERE)

    Coal with CCS Concentrating Solar Power Energy Storage Fuel Cells Geothermal Electric Natural Gas Nuclear Tidal Energy Wave Energy Wind energy BiomassBiogas Hydroelectric...

  2. Making Wave Power Efficient and Affordable | Department of Energy

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

    ARPA-E Technology Showcase: Project Spotlight Energy Department Awards 7.4 Million to Develop Advanced Components for Wave and Tidal Energy Systems Project Overview Positive ...

  3. Advancing Technology Readiness: Wave Energy Testing and Demonstration...

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

    EERE is leading the effort to prove functionality, evaluate technical and economic viability, and generate cost, performance, and reliability data for a variety of wave, tidal, and ...

  4. Current:

    Office of Legacy Management (LM)

    Qwner contacted n yes Current: ---------------------L---- if yes, date contacted Research & Development cl Facility Type 0 . Productioff 0 Di 3pcsal /Storage TYPE OF CONTRACT ---------------- q Prime q Subcontractor 0 Purchase Order 0 Other information (i.e. q cast + fixed fee, unit piice, time & material, etr) ------- ------_-----_--------------- 0 Production scale testing 0 Pilot Scale 0 Bench Scale Process a Theoretical Studies Sample & Analysis rcc t O' L~1 q Manufacturing 0

  5. Current:

    Office of Legacy Management (LM)

    OWNE3 (55) -------- past: _--_-------------------- Current: Owner contacted I-J yes ,Fqna; ------------_------------- if yes, date contacted TYPE OF OPEF(ATION ---__-------_____ c] Research & Development -4 Facility Type ci Production scale testing 0 Pilbt Scale 0 Bench Scale Process 0 Theoretical Studies 0 Sample & Analysis C Productian E Disposal/Storage TYPE OF CONTRACi _------_-------_ tlanuf acturi ng University Research Organizaticn q Prime --. _' cl Other information (i.e., cost

  6. Tidal evolution of the spin-orbit angle in exoplanetary systems

    SciTech Connect (OSTI)

    Xue, Yuxin; Suto, Yasushi; Taruya, Atsushi; Hirano, Teruyuki; Fujii, Yuka; Masuda, Kento

    2014-03-20

    The angle between the stellar spin and the planetary orbit axes (the spin-orbit angle) is supposed to carry valuable information concerning the initial condition of planetary formation and subsequent migration history. Indeed, current observations of the Rossiter-McLaughlin effect have revealed a wide range of spin-orbit misalignments for transiting exoplanets. We examine in detail the tidal evolution of a simple system comprising a Sun-like star and a hot Jupiter adopting the equilibrium tide and the inertial wave dissipation effects simultaneously. We find that the combined tidal model works as a very efficient realignment mechanism; it predicts three distinct states of the spin-orbit angle (i.e., parallel, polar, and antiparallel orbits) for a while, but the latter two states eventually approach the parallel spin-orbit configuration. The intermediate spin-orbit angles as measured in recent observations are difficult to obtain. Therefore the current model cannot reproduce the observed broad distribution of the spin-orbit angles, at least in its simple form. This indicates that the observed diversity of the spin-orbit angles may emerge from more complicated interactions with outer planets and/or may be the consequence of the primordial misalignment between the protoplanetary disk and the stellar spin, which requires future detailed studies.

  7. Current

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

    Dollars in Thousands) FY 2014 Current FY 2015 Enacted FY 2016 Request Enhanced Geothermal Systems (EGS) 27,100 32,100 45,000 Hydrothermal 10,300 12,500 36,500 Low Temperature and Coproduced 4,700 6,000 9,000 Systems Analysis 3,700 3,900 5,000 NREL Sitewide 0 500 500 Total, Geothermal Technologies 45,800 55,000 96,000 The Geothermal Technologies Office (GTO) accelerates deployment of clean, domestic geothermal energy by supporting innovative technologies that reduce the cost and risks of

  8. MHK Technologies/Deep Gen Tidal Turbines | Open Energy Information

    Open Energy Info (EERE)

    Gen Tidal Turbines < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Deep Gen Tidal Turbines.jpg Technology Profile Primary Organization Tidal...

  9. Category:Earth Tidal Analysis | Open Energy Information

    Open Energy Info (EERE)

    Earth Tidal Analysis Jump to: navigation, search Geothermalpower.jpg Looking for the Earth Tidal Analysis page? For detailed information on Earth Tidal Analysis, click here....

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

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

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

  11. A 200-A, 500-Hz, triangle current-wave modulator and magnet used for particle beam rastering

    SciTech Connect (OSTI)

    Rose, C.R.; Shafer, R.E.

    1997-10-01

    This paper describes a simple 2D beam-rastering system to uniformly spread a 100-mA 6.7-MeV cw proton beam over a 50-cm by 50-cm beam stop. The basic circuit uses a 20-mF capacitor bank, a IGBT (insulated gate bipolar transistor) full-wave inverter, and a 1-mH ferrite dipole magnet to produce a {+-} 500-Gauss peak triangular-waveform deflection field at 500 Hz. A dc input voltage of 200 volts at 2.6 amps (520 watts) produces a 160-ampere peak-to-peak triangular current waveform in the ferrite magnet at 500 Hz. For dual-axis rastering, two ferrite dipoles are used, one at 500 Hz, and the other at 575 Hz, to produce a uniform 2D beam distribution at the beam stop. The paper will discuss the IGBT modulator and ferrite deflector in detail, including current and voltage waveforms, and the ferrite magnet B-dot (dB/dt) signal.

  12. Tidal Generation Ltd | Open Energy Information

    Open Energy Info (EERE)

    Generation Ltd EMEC This company is involved in the following MHK Technologies: Deep Gen Tidal Turbines This article is a stub. You can help OpenEI by expanding it. Tidal...

  13. Tidal Flow Turbulence Measurements

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

    What)can)we)measure?) * Acous+c)Doppler)Current)Profilers)(ADCP)) - Temporal)noise) - Spa+al)aliasing)) * Acous+c)Doppler)Velocimeters)(ADVs)) * Other)op+ons) Northwest)Na+onal)Mar...

  14. ENHANCED OFF-CENTER STELLAR TIDAL DISRUPTIONS BY SUPERMASSIVE BLACK HOLES IN MERGING GALAXIES

    SciTech Connect (OSTI)

    Liu, F. K.; Chen, Xian E-mail: chenxian@pku.edu.cn

    2013-04-10

    Off-center stellar tidal disruption flares have been suggested to be a powerful probe of recoiling supermassive black holes (SMBHs) out of galactic centers due to anisotropic gravitational wave radiations. However, off-center tidal flares can also be produced by SMBHs in merging galaxies. In this paper, we computed the tidal flare rates by dual SMBHs in two merging galaxies before the SMBHs become self-gravitationally bounded. We employ an analytical model to calculate the tidal loss-cone feeding rates for both SMBHs, taking into account two-body relaxation of stars, tidal perturbations by the companion galaxy, and chaotic stellar orbits in triaxial gravitational potential. We show that for typical SMBHs with masses 10{sup 7} M{sub Sun }, the loss-cone feeding rates are enhanced by mergers up to {Gamma} {approx} 10{sup -2} yr{sup -1}, about two orders of magnitude higher than those by single SMBHs in isolated galaxies and about four orders of magnitude higher than those by recoiling SMBHs. The enhancements are mainly due to tidal perturbations by the companion galaxy. We suggest that off-center tidal flares are overwhelmed by those from merging galaxies, making the identification of recoiling SMBHs challenging. Based on the calculated rates, we estimate the relative contributions of tidal flare events by single, binary, and dual SMBH systems during cosmic time. Our calculations show that the off-center tidal disruption flares by un-bound SMBHs in merging galaxies contribute a fraction comparable to that by single SMBHs in isolated galaxies. We conclude that off-center tidal disruptions are powerful tracers of the merging history of galaxies and SMBHs.

  15. Experimental Wave Tank Test for Reference Model 3 Floating-Point Absorber Wave Energy Converter Project

    SciTech Connect (OSTI)

    Yu, Y. H.; Lawson, M.; Li, Y.; Previsic, M.; Epler, J.; Lou, J.

    2015-01-01

    The U.S. Department of Energy established a reference model project to benchmark a set of marine and hydrokinetic technologies including current (tidal, open-ocean, and river) turbines and wave energy converters. The objectives of the project were to first evaluate the status of these technologies and their readiness for commercial applications. Second, to evaluate the potential cost of energy and identify cost-reduction pathways and areas where additional research could be best applied to accelerate technology development to market readiness.

  16. Natural Currents Energy Services | Open Energy Information

    Open Energy Info (EERE)

    Wiscasset Tidal Energy Plant This company is involved in the following MHK Technologies: RED HAWK Retrieved from "http:en.openei.orgwindex.php?titleNaturalCurrentsEnergySer...

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

    SciTech Connect (OSTI)

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

    2014-02-02

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

  18. Microsoft Word - RM1_Tidal Turbine_NREL Lawson, Li Y, Sale_2011-Abstract.doc

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

    Proceedings of the 30th International Conference on Ocean, Offshore, and Arctic Engineering OMAE2011 June 19-24, 2011, Rotterdam, The Netherlands OMAE2011-49863 DEVELOPMENT AND VERIFICATION OF A COMPUTATIONAL FLUID DYNAMICS MODEL OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE ABSTRACT This paper describes the development of a computational uid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines (HATTs). First, an HATT blade was designed using the blade

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

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping

    2013-08-30

    Tidal residual eddies are one of the important hydrodynamic features in tidally dominant estuaries and coastal bays, and they could have significant effects on water exchange in a tidal system. This paper presents a modeling study of tides and tidal residual eddies in Puget Sound, a tidally dominant fjord-like estuary in the Pacific Northwest coast, using a three-dimensional finite-volume coastal ocean model. Mechanisms of vorticity generation and asymmetric distribution patterns around an island/headland were analyzed using the dynamic vorticity transfer approach and numerical experiments. Model results of Puget Sound show that a number of large twin tidal residual eddies exist in the Admiralty Inlet because of the presence of major headlands in the inlet. Simulated residual vorticities near the major headlands indicate that the clockwise tidal residual eddy (negative vorticity) is generally stronger than the anticlockwise eddy (positive vorticity) because of the effect of Coriolis force. The effect of tidal residual eddies on water exchange in Puget Sound and its sub-basins were evaluated by simulations of dye transport. It was found that the strong transverse variability of residual currents in the Admiralty Inlet results in a dominant seaward transport along the eastern shore and a dominant landward transport along the western shore of the Inlet. A similar transport pattern in Hood Canal is caused by the presence of tidal residual eddies near the entrance of the canal. Model results show that tidal residual currents in Whidbey Basin are small in comparison to other sub-basins. A large clockwise residual circulation is formed around Vashon Island near entrance of South Sound, which can potentially constrain the water exchange between the Central Basin and South Sound.

  20. MHK ISDB/Instruments/ACM-WAVE-PLUS | Open Energy Information

    Open Energy Info (EERE)

    Velocity Planar Measurement (Current), 3D Velocity Volumetric Measurement (Current), Density (Ice), Direction (Ice), Speed (Ice), Thickness (Ice), Pressure (Tidal), Sea Surface...

  1. MHK ISDB/Sensors/Vented Wave Sensor | Open Energy Information

    Open Energy Info (EERE)

    Velocity Planar Measurement (Current), 3D Velocity Volumetric Measurement (Current), Density (Ice), Direction (Ice), Speed (Ice), Thickness (Ice), Pressure (Tidal), Sea Surface...

  2. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect (OSTI)

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    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 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. 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 Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), 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.

  3. MHK Technologies/Current Catcher | Open Energy Information

    Open Energy Info (EERE)

    Primary Organization Offshore Islands Ltd Technology Resource Click here CurrentTidal Technology Type Click here Axial Flow Turbine Technology Description The Current...

  4. MHK ISDB/Instruments/Nortek Aquadopp Current Meter | Open Energy...

    Open Energy Info (EERE)

    Velocity Planar Measurement (Current), 3D Velocity Volumetric Measurement (Current), Density (Ice), Direction (Ice), Speed (Ice), Thickness (Ice), Pressure (Tidal), Sea Surface...

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

    SciTech Connect (OSTI)

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

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

  6. Current generation by helicons and LH waves in modern tokamaks and reactors FNSF-AT, ITER and DEMO. Scenarios, modeling and antennae

    SciTech Connect (OSTI)

    Vdovin, V.

    2014-02-12

    The Innovative concept and 3D full wave code modeling Off-axis current drive by RF waves in large scale tokamaks, reactors FNSF-AT, ITER and DEMO for steady state operation with high efficiency was proposed [1] to overcome problems well known for LH method [2]. The scheme uses the helicons radiation (fast magnetosonic waves at high (20–40) IC frequency harmonics) at frequencies of 500–1000 MHz, propagating in the outer regions of the plasmas with a rotational transform. It is expected that the current generated by Helicons will help to have regimes with negative magnetic shear and internal transport barrier to ensure stability at high normalized plasma pressure β{sub N} > 3 (the so-called Advanced scenarios) of interest for FNSF and the commercial reactor. Modeling with full wave three-dimensional codes PSTELION and STELEC2 showed flexible control of the current profile in the reactor plasmas of ITER, FNSF-AT and DEMO [2,3], using multiple frequencies, the positions of the antennae and toroidal waves slow down. Also presented are the results of simulations of current generation by helicons in tokamaks DIII-D, T-15MD and JT-60SA [3]. In DEMO and Power Plant antenna is strongly simplified, being some analoge of mirrors based ECRF launcher, as will be shown. For spherical tokamaks the Helicons excitation scheme does not provide efficient Off-axis CD profile flexibility due to strong coupling of helicons with O-mode, also through the boundary conditions in low aspect machines, and intrinsic large amount of trapped electrons, as is shown by STELION modeling for the NSTX tokamak. Brief history of Helicons experimental and modeling exploration in straight plasmas, tokamaks and tokamak based fusion Reactors projects is given, including planned joint DIII-D – Kurchatov Institute experiment on helicons CD [1].

  7. Earth Tidal Analysis | Open Energy Information

    Open Energy Info (EERE)

    of earth tide response of three deep, confined aquifers Earth Tidal Analysis At Raft River Geothermal Area (1980) Raft River Geothermal Area 1980 1980 Reservoir response to...

  8. Tidal Sails AS | Open Energy Information

    Open Energy Info (EERE)

    Sails AS Jump to: navigation, search Name: Tidal Sails AS Address: Standgaten 130 Place: Haugesund Zip: 5531 Region: Norway Sector: Marine and Hydrokinetic Phone Number: +32 474 98...

  9. Tidal Hydraulic Generators Ltd | Open Energy Information

    Open Energy Info (EERE)

    Hydraulic Generators Ltd Jump to: navigation, search Name: Tidal Hydraulic Generators Ltd Address: 14 Thislesboon Drive Place: Mumbles Zip: SA3 4HY Region: United Kingdom Sector:...

  10. Pennamaquan Tidal Power LLC | Open Energy Information

    Open Energy Info (EERE)

    LLC Jump to: navigation, search Name: Pennamaquan Tidal Power LLC Address: 45 Memorial Circle PO Box 1058 Place: Augusta Zip: 4332 Region: United States Sector: Marine and...

  11. Acoustic Effects of Hydrokinetic Tidal Turbines

    SciTech Connect (OSTI)

    Polagye, Brian

    2011-11-01

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

  12. Tidal Energy Test Platform | Open Energy Information

    Open Energy Info (EERE)

    Test Platform Jump to: navigation, search Basic Specifications Facility Name Tidal Energy Test Platform Overseeing Organization University of New Hampshire Hydrodynamics...

  13. Microsoft Word - RM1_Tidal Turbine_NREL Bir, Lawson, Li_2011 1.doc

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

    11 by ASME Proceedings of the ASME 30th International Conference on Ocean, Offshore and Arctic Engineering OMAE2011 June 19-24, 20111, Rotterdam, the Netherland OMAE2011-50063 STRUCTURAL DESIGN OF A HORIZONTAL-AXIS TIDAL CURRENT TURBINE COMPOSITE BLADE ABSTRACT This paper describes the structural design of a tidal turbine composite blade. The structural design is preceded by two steps: hydrodynamic design and determination of extreme loads. The hydrodynamic design provides the blade external

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

    Office of Science (SC) Website

    ORPC's TidGen(tm) turbine generator unit. R&D Opportunity Advanced water power technologies include devices capable of extracting electrical power from waves, water currents, and ...

  15. The Wash Tidal Barrier Corporation | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: The Wash Tidal Barrier Corporation Place: Cambridge, England, United Kingdom Zip: CB24 8RX Product: Company building a tidal barrier...

  16. MHK Projects/Tidal Generation Ltd EMEC | Open Energy Information

    Open Energy Info (EERE)

    Overseeing Organization Tidal Generation Ltd Project Technology *MHK TechnologiesDeep Gen Tidal Turbines Project Licensing Environmental Monitoring and Mitigation Efforts See...

  17. Hydra Tidal Energy Technology AS | Open Energy Information

    Open Energy Info (EERE)

    Tidal Energy Technology AS Jump to: navigation, search Name: Hydra Tidal Energy Technology AS Address: PO Box 399 Place: Harstad Zip: 9484 Region: Norway Sector: Marine and...

  18. Verdant-Roosevelt Island Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    Verdant-Roosevelt Island Tidal Energy Jump to: navigation, search Retrieved from "http:en.openei.orgwindex.php?titleVerdant-RooseveltIslandTidalEnergy&oldid680702" ...

  19. MHK Technologies/Sihwa tidal barrage power plant | Open Energy...

    Open Energy Info (EERE)

    Sihwa tidal barrage power plant < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Sihwa tidal barrage power plant.jpg Technology Profile...

  20. MHK Technologies/Tidal Delay | Open Energy Information

    Open Energy Info (EERE)

    Tidal Delay < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tidal Delay.png Technology Profile Primary Organization Woodshed Technologies Ltd...

  1. Severn Tidal Power Group STpg | Open Energy Information

    Open Energy Info (EERE)

    Severn Tidal Power Group STpg Jump to: navigation, search Name: Severn Tidal Power Group STpg Region: United Kingdom Sector: Marine and Hydrokinetic Website: http: This company is...

  2. MHK Technologies/Jiangxia Tidal Power Station | Open Energy Informatio...

    Open Energy Info (EERE)

    Jiangxia Tidal Power Station < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Jiangxia Tidal Power Station.jpg Technology Profile Primary...

  3. MHK Technologies/Scotrenewables Tidal Turbine SRTT | Open Energy...

    Open Energy Info (EERE)

    Tidal Turbine SRTT < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Scotrenewables Tidal Turbine SRTT.jpg Technology Profile Primary...

  4. MHK Technologies/Rotech Tidal Turbine RTT | Open Energy Information

    Open Energy Info (EERE)

    Rotech Tidal Turbine RTT < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Rotech Tidal Turbine RTT.jpg Technology Profile Primary Organization...

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

    SciTech Connect (OSTI)

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

    2014-11-01

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

  6. Effects of the radial dependence of the fast electron diffusion coefficient on the current driven by lower-hybrid waves in tokamak

    SciTech Connect (OSTI)

    Zhang Xianmei; Wang Yanhui; Yu Limin; Shen Xin; Wang Jianbin

    2012-07-15

    The lower hybrid current drive (LHCD) is one of the promising methods not only for driving the non-inductive current required for steady-state tokamak operation, but also for controlling the plasma current profile to improve confinement in tokamak experiments. A direct consequence of experimental imperfection is difficult to obtain reliable estimate of the radial diffusion coefficient (D{sub st}) of the lower hybrid driven current. In this paper, the radial profile of D{sub st} is estimated to investigate its effect on the current driven by lower hybrid wave (LHW) in Experimental Advanced Superconducting Tokamak. Compared with the case of the constant radial diffusion coefficient, the efficiency of LHW driven current with the radial dependent diffusion coefficient D{sub st} ({rho}) becomes either higher or lower with respect to the plasma parameters, such as the density and the magnetic fluctuation. It is also found that the profiles of the LHW driven current are different. Therefore, it is necessary to consider the radial dependence of D{sub st} in order to get an accurate and reliable result in the numerical simulation of LHCD.

  7. Wave Energy | Open Energy Information

    Open Energy Info (EERE)

    Wave Energy Jump to: navigation, search Contents 1 Description 2 History 3 Technology 4 Current and Possible Wave Farms 5 Pros and Cons Description Wave energy (or wave power) is...

  8. Feasibility of Tital and Ocean Current Energy in False Pass,...

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

    - Alaska Feasibility of Tidal and Ocean Current Energy in False Pass, Aleutian Islands, ... to seven sites to assess hazards to successful ADCP deployment and retrieval. ...

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

    SciTech Connect (OSTI)

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

    2012-06-05

    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.

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

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

    Brian Polagye Northwest National Marine Renewable Energy Center University of Washington, Seattle, WA Introduction Reference Model 1 is a tidal turbine operating in a narrow, ...

  11. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect (OSTI)

    Not Available

    1980-11-01

    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.

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

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

    Basics Hydropower Basics Content on this page requires a newer version of Adobe Flash Player. Get Adobe Flash player Most people associate water power with the Hoover Dam-a huge facility harnessing the power of an entire river behind its walls-but hydropower facilities come in all sizes. Some may be very large, but they can be tiny too, taking advantage of water flows in municipal water facilities or irrigation ditches. They can even be "dam-less," with diversions or run-of-river

  13. Feasibility of Tidal and Ocean Current Energy in False Pass,...

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

    ... Marsh Creek, LLC 1172013 3 | P a g e Marsh Creek, ......... 6 Diesel Generator Sets ... 8 Cooling System ......

  14. OPTICAL TRANSIENTS FROM THE UNBOUND DEBRIS OF TIDAL DISRUPTION

    SciTech Connect (OSTI)

    Kasen, Daniel; Ramirez-Ruiz, Enrico

    2010-05-01

    In the tidal disruption of a star by a black hole, roughly half of the stellar mass becomes bound and falls into the black hole, while the other half is ejected at high velocity. Several previous studies have considered the emission resulting from the accretion of bound material; we consider the possibility that the unbound debris may also radiate once it has expanded and become transparent. We show that the gradual energy input from hydrogen recombination compensates for adiabatic losses over significant expansion factors. The opacity also drops dramatically with recombination, and the internal energy can be radiated by means of a cooling-transparency wave propagating from the surface layers inward. The result is a brief optical transient occurring {approx} 1 week after disruption and lasting 3-5 days with peak luminosities of 10{sup 40}-10{sup 42} ergs s{sup -1}, depending on the mass of the disrupted star. These recombination powered transients should accompany the X-ray/ultraviolet flare from the accretion of bound material, and so may be a useful signature for discriminating tidal disruption events, especially for lower and intermediate mass black holes.

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

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

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

    2014-12-17

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

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

    SciTech Connect (OSTI)

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

    2014-12-17

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

  17. MHK Technologies/Tidal Sails | Open Energy Information

    Open Energy Info (EERE)

    to wires strung across the tidal stream at an angle The sails are driven back and forth by the tidal flow between two stations at one of which the generator is installed...

  18. Ocean current resource assessment | Department of Energy

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

    Ocean current resource assessment Ocean current resource assessment Ocean current resource assessment 45_ocean_resource_gtrc_haas.ppt (531 KB) More Documents & Publications Tidal Energy Resource Assessment Free Flow Energy (TRL 1 2 3 Component) - Design and Development of a Cross-Platform Submersible Generator Optimized for the Conditions of Current Energy Conversion

  19. Mapping the Potential of U.S. Ocean Energy | Department of Energy

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

    available in the nation's waves, tidal and river currents, and ocean thermal gradients. ... and global wave, tidal, ocean thermal, and continental U.S. river hydrokinetic resources. ...

  20. Power Generation for River and Tidal Generators

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

    Power Generation for River and Tidal Generators Eduard Muljadi, Alan Wright, and Vahan Gevorgian National Renewable Energy Laboratory James Donegan, Cian Marnagh, and Jarlath McEntee Ocean Renewable Power Company Technical Report NREL/TP-5D00-66097 June 2016 NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost from the National Renewable Energy

  1. Tidal heating in multilayered terrestrial exoplanets

    SciTech Connect (OSTI)

    Henning, Wade G.; Hurford, Terry

    2014-07-01

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

  2. 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

    2012-03-30

    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

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

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Earth Tidal Analysis At Raft River Geothermal Area (1984) Exploration Activity Details Location Raft River...

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

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Earth Tidal Analysis At Raft River Geothermal Area (1982) Exploration Activity Details Location Raft River...

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

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Earth Tidal Analysis At Raft River Geothermal Area (1980) Exploration Activity Details Location Raft River...

  6. MHK Projects/Tidal Energy Project Portugal | Open Energy Information

    Open Energy Info (EERE)

    Organization Tidal Energy Pty Ltd Project Technology *MHK TechnologiesDavidson Hill Venturi DHV Turbine Project Licensing Environmental Monitoring and Mitigation Efforts See...

  7. MHK Technologies/Tidal Stream | Open Energy Information

    Open Energy Info (EERE)

    Click here TRL 1-3: Discovery Concept Definition Early Stage Development & Design & Engineering Technology Description The TidalStream SST (Semi-Submersible Turbine) is...

  8. MHK Projects/Astoria Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    Astoria Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMA...

  9. MHK Projects/Cape Islands Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Islands Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type"...

  10. MHK Projects/Town of Wiscasset Tidal Resources | Open Energy...

    Open Energy Info (EERE)

    Town of Wiscasset Tidal Resources < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","...

  11. MHK Projects/Indian River Tidal Hydrokinetic Energy Project ...

    Open Energy Info (EERE)

    Tidal Hydrokinetic Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","...

  12. MHK Projects/Angoon Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    Angoon Tidal Energy Plant < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"R...

  13. MHK Projects/Kendall Head Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    Kendall Head Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"R...

  14. MHK Projects/Kingsbridge Tidal Energy Project | Open Energy Informatio...

    Open Energy Info (EERE)

    Kingsbridge Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","t...

  15. MHK Projects/Roosevelt Island Tidal Energy RITE | Open Energy...

    Open Energy Info (EERE)

    Roosevelt Island Tidal Energy RITE < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3",...

  16. MHK Projects/Kachemak Bay Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Kachemak Bay Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","...

  17. MHK Projects/Pennamaquan Tidal Power Plant | Open Energy Information

    Open Energy Info (EERE)

    Phase Phase ? PermitLicense Buildout (MW) 21 Main Overseeing Organization Pennamaquan Tidal Power LLC Project Licensing FERC License Docket Number P-13884 Environmental...

  18. MHK Projects/Central Cook Inlet Alaska Tidal Energy Project ...

    Open Energy Info (EERE)

    Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMA...

  19. MHK Projects/Portsmouth Area Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Portsmouth Area Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3...

  20. MHK Projects/Deception Pass Tidal Energy Hydroelectric Project...

    Open Energy Info (EERE)

    Deception Pass Tidal Energy Hydroelectric Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice"...

  1. MHK Projects/Edgar Town Nantucket Tidal Energy | Open Energy...

    Open Energy Info (EERE)

    Town Nantucket Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":...

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

    Open Energy Info (EERE)

    Housatonic Tidal Energy Plant < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type...

  3. MHK Projects/East Foreland Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    East Foreland Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"...

  4. MHK Projects/Turnagain Arm Tidal | Open Energy Information

    Open Energy Info (EERE)

    Turnagain Arm Tidal < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP...

  5. MHK Projects/Cuttyhunk Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    Cuttyhunk Tidal Energy Plant < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type"...

  6. MHK Projects/Spieden Channel Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Spieden Channel Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3...

  7. MHK Projects/Muskeget Channel Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    Muskeget Channel Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type...

  8. MHK Projects/Nantucket Tidal Energy Plant | Open Energy Information

    Open Energy Info (EERE)

    Nantucket Tidal Energy Plant < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type"...

  9. MHK Projects/Avalon Tidal | Open Energy Information

    Open Energy Info (EERE)

    Avalon Tidal < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom...

  10. MHK Projects/Piscataqua Tidal Hydrokinetic Energy Project | Open...

    Open Energy Info (EERE)

    Piscataqua Tidal Hydrokinetic Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"goo...

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

    Open Energy Info (EERE)

    Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMA...

  12. MHK Projects/Penobscot Tidal Energy Project | Open Energy Information

    Open Energy Info (EERE)

    Penobscot Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","typ...

  13. MHK Projects/Treat Island Tidal | Open Energy Information

    Open Energy Info (EERE)

    Treat Island Tidal < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP"...

  14. MHK Projects/Cook Inlet Tidal Energy | Open Energy Information

    Open Energy Info (EERE)

    Cook Inlet Tidal Energy < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"ROA...

  15. MHK Projects/Paimpol Brehat tidal farm | Open Energy Information

    Open Energy Info (EERE)

    Paimpol Brehat tidal farm < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type":"R...

  16. MHK Projects/Guemes Channel Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Guemes Channel Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3"...

  17. MHK Technologies/Tidal Barrage | Open Energy Information

    Open Energy Info (EERE)

    < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tidal Barrage.jpg Technology Profile Technology Type Click here Cross Flow Turbine...

  18. MHK Projects/Tacoma Narrows Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Tacoma Narrows Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3"...

  19. MHK Technologies/TidalStar | Open Energy Information

    Open Energy Info (EERE)

    search << Return to the MHK database homepage TidalStar.jpg Technology Profile Primary Organization Bourne Energy Technology Type Click here Axial Flow Turbine...

  20. MHK Technologies/Tidal Turbine | Open Energy Information

    Open Energy Info (EERE)

    Turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tidal Turbine.jpg Technology Profile Primary Organization Aquascientific Project(s)...

  1. MHK Technologies/Tidal Stream Turbine | Open Energy Information

    Open Energy Info (EERE)

    Turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Tidal Stream Turbine.jpg Technology Profile Primary Organization StatoilHydro co owned...

  2. MHK Projects/Seaflow Tidal Energy System | Open Energy Information

    Open Energy Info (EERE)

    been operating the Seaflow Tidal Energy System project since May 2003. This was an experimental test rig - the successor, SeaGen is intended for commercial applications Project...

  3. OPTICAL DISCOVERY OF PROBABLE STELLAR TIDAL DISRUPTION FLARES

    SciTech Connect (OSTI)

    Van Velzen, Sjoert; Farrar, Glennys R.; Gezari, Suvi; Morrell, Nidia; Zaritsky, Dennis; Oestman, Linda; Smith, Mathew; Gelfand, Joseph; Drake, Andrew J.

    2011-11-10

    Using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82), we have searched for the tidal disruption of stars by supermassive black holes in non-active galaxies. Two candidate tidal disruption events (TDEs) are identified. The TDE flares have optical blackbody temperatures of 2 Multiplication-Sign 10{sup 4} K and observed peak luminosities of M{sub g} = -18.3 and -20.4 ({nu}L{sub {nu}} = 5 Multiplication-Sign 10{sup 42}, 4 Multiplication-Sign 10{sup 43} erg s{sup -1}, in the rest frame); their cooling rates are very low, qualitatively consistent with expectations for tidal disruption flares. The properties of the TDE candidates are examined using (1) SDSS imaging to compare them to other flares observed in the search, (2) UV emission measured by GALEX, and (3) spectra of the hosts and of one of the flares. Our pipeline excludes optically identifiable AGN hosts, and our variability monitoring over nine years provides strong evidence that these are not flares in hidden AGNs. The spectra and color evolution of the flares are unlike any SN observed to date, their strong late-time UV emission is particularly distinctive, and they are nuclear at high resolution arguing against these being first cases of a previously unobserved class of SNe or more extreme examples of known SN types. Taken together, the observed properties are difficult to reconcile with an SN or an AGN-flare explanation, although an entirely new process specific to the inner few hundred parsecs of non-active galaxies cannot be excluded. Based on our observed rate, we infer that hundreds or thousands of TDEs will be present in current and next-generation optical synoptic surveys. Using the approach outlined here, a TDE candidate sample with O(1) purity can be selected using geometric resolution and host and flare color alone, demonstrating that a campaign to create a large sample of TDEs, with immediate and detailed multi-wavelength follow-up, is feasible. A by-product of this

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

    SciTech Connect (OSTI)

    Shiu, Henry; van Dam, Cornelis P.

    2013-08-22

    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

  5. 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.

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

    SciTech Connect (OSTI)

    Worthington, Monty

    2014-02-05

    Cook Inlet, Alaska is home to some of the greatest tidal energy resources in the U.S., as well as an endangered population of beluga whales (Delphinapterus leucas). Successfully permitting and operating a tidal power project in Cook Inlet requires a biological assessment of the potential and realized effects of the physical presence and sound footprint of tidal turbines on the distribution, relative abundance, and behavior of Cook Inlet beluga whales. ORPC Alaska, working with the Project Team—LGL Alaska Research Associates, University of Alaska Anchorage, TerraSond, and Greeneridge Science—undertook the following U.S. Department of Energy (DOE) study to characterize beluga whales in Cook Inlet – Acoustic Monitoring of Beluga Whale Interactions with the Cook Inlet Tidal Energy Project (Project). ORPC Alaska, LLC, is a wholly-owned subsidiary of Ocean Renewable Power Company, LLC, (collectively, ORPC). ORPC is a global leader in the development of hydrokinetic power systems and eco-conscious projects that harness the power of ocean and river currents to create clean, predictable renewable energy. ORPC is developing a tidal energy demonstration project in Cook Inlet at East Foreland where ORPC has a Federal Energy Regulatory Commission (FERC) preliminary permit (P-13821). The Project collected baseline data to characterize pre-deployment patterns of marine mammal distribution, relative abundance, and behavior in ORPC’s proposed deployment area at East Foreland. ORPC also completed work near Fire Island where ORPC held a FERC preliminary permit (P-12679) until March 6, 2013. Passive hydroacoustic devices (previously utilized with bowhead whales in the Beaufort Sea) were adapted for study of beluga whales to determine the relative abundance of beluga whale vocalizations within the proposed deployment areas. Hydroacoustic data collected during the Project were used to characterize the ambient acoustic environment of the project site pre-deployment to inform the

  7. Admiralty Inlet Pilot Tidal Project Final Technical Report

    SciTech Connect (OSTI)

    Collar, Craig

    2015-09-14

    This document represents the final report for the Admiralty Inlet Pilot Tidal Project, located in Puget Sound, Washington, United States. The Project purpose was to license, permit, and install a grid-connected deep-water tidal turbine array (two turbines) to be used as a platform to gather operational and environmental data on tidal energy generation. The data could then be used to better inform the viability of commercial tidal energy generation from technical, economic, social, and environmental standpoints. This data would serve as a critical step towards the responsible advancement of commercial scale tidal energy in the United States and around the world. In late 2014, Project activities were discontinued due to escalating costs, and the DOE award was terminated in early 2015. Permitting, licensing, and engineering design activities were completed under this award. Final design, deployment, operation, and monitoring were not completed. This report discusses the results and accomplishments achieved under the subject award.

  8. CONSTRAINING TIDAL DISSIPATION IN STARS FROM THE DESTRUCTION RATES OF EXOPLANETS

    SciTech Connect (OSTI)

    Penev, Kaloyan; Jackson, Brian; Spada, Federico; Thom, Nicole

    2012-06-01

    We use the distribution of extrasolar planets in circular orbits around stars with surface convective zones detected by ground-based transit searches to constrain how efficiently tides raised by the planet are dissipated on the parent star. We parameterize this efficiency as a tidal quality factor (Q{sub *}). We conclude that the population of currently known planets is inconsistent with Q{sub *} < 10{sup 7} at the 99% level. Previous studies show that values of Q{sub *} between 10{sup 5} and 10{sup 7} are required in order to explain the orbital circularization of main-sequence low-mass binary stars in clusters, suggesting that different dissipation mechanisms might be acting in the two cases, most likely due to the very different tidal forcing frequencies relative to the stellar rotation frequency occurring for star-star versus planet-star systems.

  9. TIDALLY DRIVEN DYNAMOS IN A ROTATING SPHERE

    SciTech Connect (OSTI)

    Cébron, D.; Hollerbach, R. E-mail: r.hollerbach@leeds.ac.uk

    2014-07-01

    Large-scale planetary or stellar magnetic fields generated by a dynamo effect are mostly attributed to flows forced by buoyancy forces in electrically conducting fluid layers. However, these large-scale fields may also be controlled by tides, as previously suggested for the star τ-boo, Mars, or the early Moon. By simulating a small local patch of a rotating fluid, Barker and Lithwick have recently shown that tides can drive small-scale dynamos by exciting a hydrodynamic instability, the so-called elliptical (or tidal) instability. By performing global magnetohydrodynamic simulations of a rotating spherical fluid body, we investigate if this instability can also drive the observed large-scale magnetic fields. We are thus interested in the dynamo threshold and the generated magnetic field in order to test if such a mechanism is relevant for planets and stars. Rather than solving the problem in a geometry deformed by tides, we consider a spherical fluid body and add a body force to mimic the tidal deformation in the bulk of the fluid. This allows us to use an efficient spectral code to solve the magnetohydrodynamic problem. We first compare the hydrodynamic results with theoretical asymptotic results and numerical results obtained in a truly deformed ellipsoid, which confirms the presence of elliptical instability. We then perform magnetohydrodynamic simulations and investigate the dynamo capability of the flow. Kinematic and self-consistent dynamos are finally simulated, showing that the elliptical instability is capable of generating a dipole-dominated large-scale magnetic field in global simulations of a fluid rotating sphere.

  10. SQUARE WAVE AMPLIFIER

    DOE Patents [OSTI]

    Leavitt, M.A.; Lutz, I.C.

    1958-08-01

    An amplifier circuit is described for amplifying sigmals having an alternating current component superimposed upon a direct current component, without loss of any segnnent of the alternating current component. The general circuit arrangement includes a vibrator, two square wave amplifiers, and recombination means. The amplifier input is connected to the vibrating element of the vibrator and is thereby alternately applied to the input of each square wave amplifier. The detailed circuitry of the recombination means constitutes the novelty of the annplifier and consists of a separate, dual triode amplifier coupled to the output of each square wave amplifier with a recombination connection from the plate of one amplifier section to a grid of one section of the other amplifier. The recombination circuit has provisions for correcting distortion caused by overlapping of the two square wave voltages from the square wave amplifiers.

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

    SciTech Connect (OSTI)

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

    1990-09-01

    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.

  12. Pulse Tidal formerly Pulse Generation | Open Energy Information

    Open Energy Info (EERE)

    formerly Pulse Generation Jump to: navigation, search Name: Pulse Tidal (formerly Pulse Generation) Place: Hull, England, United Kingdom Zip: HU5 3LP Product: UK-based developer of...

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

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

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

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

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

    Assessment of Energy Production Potential from Tidal Streams in the United States Final ... Award Number: DE-FG36-08GO18174 Project Title: Assessment of Energy Production Potential ...

  15. Challenges and Instrumentation Solutions to Understanding the Nature of Tidal Flows

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

    ChallengeHER 10-26-2016 Downloadable Flyer ChallengeHER 10-26-2016 Downloadable Flyer Opportunities for Women in Federal Contracting Event ChallengeHER-10-26-2016-rev2.pdf (597.08 KB) More Documents & Publications ChallengeHER-2015-Flyer Contract Connections @ ChallengeHER, Norfolk VA, October 14 Overview of Various Socioeconomic Categories - Ann Sullivan

    Integrated Approach to Characterization of Full-Spectrum Turbulence Near Current Tidal Energy Devices Presented by Brett Prairie of

  16. Current-wave spectra coupling project. Volume IV. Part A. Formulation of the three-dimensional structure of storm-generated currents. Part B. Summaries of Volumes I, II and III

    SciTech Connect (OSTI)

    Venezian, G.; Bretschneider, C.L.

    1980-09-01

    An attempt is made to formulate the technical approach to the problem of three dimensional wind driven currents under hurricane conditions. Reference is given to the splendid piece of research on the subject by Forristall (1974) Three-dimensional structure of storm-generated currents, J. Geophys. Res. 79, 2721-2727. The present approach, although not entirely satisfactory, seems to be an improvement on the work by Forristall, but this remains to be verified with future work, including the use of measured data. An improvement could be made if there were some better way of representing the shear stress as a function of the wind velocity (wind speed and direction). It seems that the wind velocity relative to the water motion is what matters, but in turbulent flow the surface value is not well defined. This difficulty leaves one with an unbalanced vortex stretching which accounts for the spin-up of the fluid, but the details of that are lacking. Essentially, it appears that it is feasible to modify Forristall's approach to obtain a more realistic representation of the structure of the boundary layer to take into account the turbulent nature of the flow.

  17. TIDAL DISRUPTION FLARES: THE ACCRETION DISK PHASE

    SciTech Connect (OSTI)

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

    2011-08-01

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

  18. Discovery of a tidal dwarf galaxy in the Leo Triplet

    SciTech Connect (OSTI)

    Nikiel-Wroczy?ski, B.; Soida, M.; Urbanik, M.; Bomans, D. J. E-mail: soida@oa.uj.edu.pl E-mail: bomans@astro.rub.de

    2014-05-10

    We report the discovery of a dwarf galaxy in the Leo Triplet. Analysis of the neutral hydrogen distribution shows that it rotates independently of the tidal tail of NGC 3628, with a radial velocity gradient of 35-40 km s{sup 1} over approximately 13 kpc. The galaxy has an extremely high neutral gas content, accounting for a large amount of its total dynamic mass and suggesting a low amount of dark matter. It is located at the tip of the gaseous tail, which strongly suggests a tidal origin. If this is the case, it would be one of the most confident and nearest (to the Milky Way) detections of a tidal dwarf galaxy and, at the same time, the object most detached from its parent galaxy (?140 kpc) of this type.

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

    SciTech Connect (OSTI)

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

    2011-06-29

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

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  1. Application to Export Electric Energy OE Docket No. EA-422 Tidal Energy

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

    Marketing Inc. | Department of Energy Application to Export Electric Energy OE Docket No. EA-422 Tidal Energy Marketing Inc. Application from Tidal to export electric energy to Canada. EA-422 Tidal Energy Mktg. (CN).pdf (282.23 KB) More Documents & Publications Application to Export Electric Energy OE Docket No. EA-422 Tidal Energy Marketing Inc.: Federal Register Notice, Volume 81, No. 133 - July 12, 2016 Application to Export Electric Energy OE Docket No. EA-258-D Brookefield Energy

  2. DeFrees Small Wave Basin | Open Energy Information

    Open Energy Info (EERE)

    Current Velocity Range(ms) 0.0 Programmable Wavemaking Yes Wavemaking Description Computer controlled hydraulic paddle, arbitrary wave shape possible Wave Direction...

  3. Proceedings of the Hydrokinetic and Wave Energy Technologies Technical and Environmental Issues Workshop

    SciTech Connect (OSTI)

    2006-03-01

    Renewable energy technologies offer the promise of non-polluting alternatives to fossil and nuclear-fueled power plants to meet growing demand for electrical energy. Two emerging categories of renewable energy technologies, hydrokinetic and wave energy conversion devices, offer ways to tap the energy of moving water without impoundment (dams) or diversion required by many conventional hydroelectric facilities. These technologies include devices designed for deployment in natural streams, tidal estuaries, ocean currents, and constructed waterways, as well as devices designed to capture the energy of ocean waves. On October 26-28, 2005, 54 representatives from government, non-governmental organizations, and private business met to (1) identify the varieties of hydrokinetic energy and wave technology devices, their stages of development, and the projected cost to bring each to market; (2) identify where these technologies can best operate; (3) identify the potential environmental issues associated with these technologies and possible mitigation measures; (4) develop a list of research needs and/or practical solutions to address unresolved environmental issues. These workshop proceedings include detailed summaries of the 24 presentations made and the discussions that followed.

  4. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  5. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  6. ON THE EFFICIENCY OF THE TIDAL STIRRING MECHANISM FOR THE ORIGIN OF DWARF SPHEROIDALS: DEPENDENCE ON THE ORBITAL AND STRUCTURAL PARAMETERS OF THE PROGENITOR DISKY DWARFS

    SciTech Connect (OSTI)

    Kazantzidis, Stelios; Lokas, Ewa L.; Callegari, Simone; Mayer, Lucio; Moustakas, Leonidas A. E-mail: lokas@camk.edu.pl E-mail: lucio@phys.ethz.ch

    2011-01-10

    The tidal stirring model posits the formation of dwarf spheroidal galaxies (dSphs) via the tidal interactions between late-type, rotationally supported dwarfs and Milky-Way-sized host galaxies. Using a comprehensive set of collisionless N-body simulations, we investigate the efficiency of the tidal stirring mechanism for the origin of dSphs. In particular, we examine the degree to which the tidal field of the primary galaxy affects the sizes, masses, shapes, and kinematics of the disky dwarfs for a range of dwarf orbital and structural parameters. Our study is the first to employ self-consistent, equilibrium models for the progenitor dwarf galaxies constructed from a composite distribution function and consisting of exponential stellar disks embedded in massive, cosmologically motivated dark matter halos. Exploring a wide variety of dwarf orbital configurations and initial structures, we demonstrate that in the majority of cases the disky dwarfs experience significant mass loss and their stellar distributions undergo a dramatic morphological, as well as dynamical, transformation. Specifically, the stellar components evolve from disks to bars and finally to pressure-supported, spheroidal systems with kinematic and structural properties akin to those of the classic dSphs in the Local Group (LG) and similar environments. The self-consistency of the adopted dwarf models is crucial for confirming this complex transformation process via tidally induced dynamical instabilities and impulsive tidal heating of the stellar distribution. Our results suggest that such tidal transformations should be common occurrences within the currently favored cosmological paradigm and highlight the key factor responsible for an effective metamorphosis to be the strength of the tidal shocks at the pericenters of the orbit. We also demonstrate that the combination of short orbital times and small pericentric distances, characteristic of dwarfs being accreted by their hosts at high redshift

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

    SciTech Connect (OSTI)

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

    2012-12-29

    The Islands of Martha's Vineyard and Nantucket are separated from the Massachusetts mainland by Vineyard and Nantucket Sounds; water between the two islands flows through Muskeget Channel. The towns of Edgartown (on Martha's Vineyard) and Nantucket recognize that they are vulnerable to power supply interruptions due to their position at the end of the power grid, and due to sea level rise and other consequences of climate change. The tidal energy flowing through Muskeget Channel has been identified by the Electric Power Research Institute as the strongest tidal resource in Massachusetts waters. The Town of Edgartown proposes to develop an initial 5 MW (nameplate) tidal energy project in Muskeget Channel. The project will consist of 14 tidal turbines with 13 providing electricity to Edgartown and one operated by the University of Massachusetts at Dartmouth for research and development. Each turbine will be 90 feet long and 50 feet high. The electricity will be brought to shore by a submarine cable buried 8 feet below the seabed surface which will landfall in Edgartown either on Chappaquiddack or at Katama. Muskeget Channel is located between Martha's Vineyard and Nantucket. Its depth ranges between 40 and 160 feet in the deepest portion. It has strong currents where water is transferred between Nantucket Sound and the Atlantic Ocean continental shelf to the south. This makes it a treacherous passage for navigation. Current users of the channel are commercial and recreational fishing, and cruising boats. The US Coast Guard has indicated that the largest vessel passing through the channel is a commercial scallop dragger with a draft of about 10 feet. The tidal resource in the channel has been measured by the University of Massachusetts-Dartmouth and the peak velocity flow is approximately 5 knots. The technology proposed is the helical Gorlov-type turbine positioned with a horizontal axis that is positively buoyant in the water column and held down by anchors. This is

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

    SciTech Connect (OSTI)

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

    2014-09-30

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

  9. POSSIBLE ORIGIN OF THE G2 CLOUD FROM THE TIDAL DISRUPTION OF A KNOWN GIANT STAR BY SGR A*

    SciTech Connect (OSTI)

    Guillochon, James; Loeb, Abraham; MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2014-05-10

    The discovery of the gas cloud G2 on a near-radial orbit about SgrA* has prompted much speculation on its origin. In this Letter, we propose that G2 formed out of the debris stream produced by the removal of mass from the outer envelope of a nearby giant star. We perform hydrodynamical simulations of the returning tidal debris stream with cooling and find that the stream condenses into clumps that fall periodically onto SgrA*. We propose that one of these clumps is the observed G2 cloud, with the rest of the stream being detectable at lower Br? emissivity along a trajectory that would trace from G2 to the star that was partially disrupted. By simultaneously fitting the orbits of S2, G2, and ?2000 candidate stars, and by fixing the orbital plane of each candidate star to G2 (as is expected for a tidal disruption), we find that several stars have orbits that are compatible with the notion that one of them was tidally disrupted to produce G2. If one of these stars were indeed disrupted, it last encountered SgrA* hundreds of years ago and has likely encountered SgrA* repeatedly. However, while these stars are compatible with the giant disruption scenario given their measured positions and proper motions, their radial velocities are currently unknown. If one of these stars' radial velocity is measured to be compatible with a disruptive orbit, it would strongly suggest that its disruption produced G2.

  10. New Job Opening in Water Power Program | Department of Energy

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

    the advancement of innovative wave, tidal, ocean, and river current energy conversion technologies. ... development, demonstration, and deployment of innovative technologies. ...

  11. RBS 1032: A TIDAL DISRUPTION EVENT IN ANOTHER DWARF GALAXY?

    SciTech Connect (OSTI)

    Maksym, W. Peter; Lin, Dacheng; Irwin, Jimmy A.

    2014-09-10

    RBS 1032 is a supersoft (? ? 5), luminous (?10{sup 43} erg s{sup 1}) ROSAT PSPC source which has been associated with an inactive dwarf galaxy at z = 0.026, SDSS J114726.69+494257.8. We have analyzed an XMM-Newton observation that confirms that RBS 1032 is indeed associated with the dwarf galaxy. Moreover, RBS 1032 has undergone a factor of ?100-300 decay since 1990 November. This variability suggests that RBS 1032 may not be a steadily accreting intermediate-mass black hole, but rather an accretion flare from the tidal disruption of a star by the central black hole (which may or may not be intermediate-mass). We suggest that additional tidal disruption events may remain unidentified in archival ROSAT data, such that disruption rate estimates based upon ROSAT All-Sky Survey data may need reconsideration.

  12. High Fidelity Evaluation of Tidal Turbine Performance for Industry Partner

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

    Fidelity Evaluation of Tidal Turbine Performance for Industry Partner - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy

  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. Collisional disruption of gravitational aggregates in the tidal environment

    SciTech Connect (OSTI)

    Hyodo, Ryuki; Ohtsuki, Keiji

    2014-05-20

    The degree of disruption in collisions in free space is determined by specific impact energy, and the mass fraction of the largest remnant is a monotonically decreasing function of impact energy. However, it has not been shown whether such a relationship is applicable to collisions under the influence of a planet's tidal force, which is important in ring dynamics and satellite accretion. Here we examine the collisional disruption of gravitational aggregates in the tidal environment by using local N-body simulations. We find that outcomes of such a collision largely depend on the impact velocity, the direction of impact, and the radial distance from the planet. In the case of a strong tidal field corresponding to Saturn's F ring, collisions in the azimuthal direction are much more destructive than those in the radial direction. Numerical results of collisions sensitively depend on the impact velocity, and a complete disruption of aggregates can occur even in impacts with velocity much lower than their escape velocity. In such low-velocity collisions, the deformation of colliding aggregates plays an essential role in determining collision outcomes, because the physical size of the aggregate is comparable to its Hill radius. On the other hand, the dependence of collision outcomes on impact velocity becomes similar to the case in free space when the distance from the planet is sufficiently large. Our results are consistent with Cassini observations of the F ring, which suggest ongoing creation and disruption of aggregates within the ring.

  15. Maine Deploys First U.S. Commercial, Grid-Connected Tidal Energy Project |

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

    Department of Energy Maine Deploys First U.S. Commercial, Grid-Connected Tidal Energy Project Maine Deploys First U.S. Commercial, Grid-Connected Tidal Energy Project July 24, 2012 - 1:12pm Addthis NEWS MEDIA CONTACT (202) 586-4940 WASHINGTON -- Today, Energy Secretary Steven Chu recognized the nation's first commercial, grid-connected tidal energy project off the coast of Eastport, Maine. Leveraging a $10 million investment from the Energy Department, Ocean Renewable Power Company (ORPC)

  16. Application to Export Electric Energy OE Docket No. EA-422 Tidal Energy

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

    Marketing Inc.: Federal Register Notice, Volume 81, No. 133 - July 12, 2016 | Department of Energy : Federal Register Notice, Volume 81, No. 133 - July 12, 2016 Application to Export Electric Energy OE Docket No. EA-422 Tidal Energy Marketing Inc.: Federal Register Notice, Volume 81, No. 133 - July 12, 2016 Application from Tidal to export electric energy. Federal Register Notice. EA-422 Tidal Energy Mktg. CN.pdf (170.02 KB) More Documents & Publications Application to Export Electric

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

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: AC05-76RL01830 Resource Type: Journal Article Resource Relation: Journal Name: Applied Physics Letters, 105(2):Article No. 023902 Research Org: Pacific ...

  18. Mirror force induced wave dispersion in Alfvn waves

    SciTech Connect (OSTI)

    Damiano, P. A.; Johnson, J. R.

    2013-06-15

    Recent hybrid MHD-kinetic electron simulations of global scale standing shear Alfvn waves along the Earth's closed dipolar magnetic field lines show that the upward parallel current region within these waves saturates and broadens perpendicular to the ambient magnetic field and that this broadening increases with the electron temperature. Using resistive MHD simulations, with a parallel Ohm's law derived from the linear Knight relation (which expresses the current-voltage relationship along an auroral field line), we explore the nature of this broadening in the context of the increased perpendicular Poynting flux resulting from the increased parallel electric field associated with mirror force effects. This increased Poynting flux facilitates wave energy dispersion across field lines which in-turn allows for electron acceleration to carry the field aligned current on adjacent field lines. This mirror force driven dispersion can dominate over that associated with electron inertial effects for global scale waves.

  19. Snohomish PUD No 1 (TRL 7 8 System) - Puget Sound Pilot Tidal Energy

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

    Project | Department of Energy Snohomish PUD No 1 (TRL 7 8 System) - Puget Sound Pilot Tidal Energy Project Snohomish PUD No 1 (TRL 7 8 System) - Puget Sound Pilot Tidal Energy Project Snohomish PUD No 1 (TRL 7 8 System) - Puget Sound Pilot Tidal Energy Project 01_puget_snopud_presentation.pptx (4.28 MB) More Documents & Publications Ocean Renewable Power Co (ORPC) (TRL 7 8 System) - TidGen (TM) Power System Commercialization Project Sunlight Photonics (TRL 4 System) - Tidal Energy

  20. MHK Projects/Homeowner Tidal Power Elec Gen | Open Energy Information

    Open Energy Info (EERE)

    Homeowner Tidal Power Elec Gen < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","typ...

  1. EERE Success Story-Measuring the Impact of Tidal Power Installations on

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

    Endangered Beluga Whales | Department of Energy Measuring the Impact of Tidal Power Installations on Endangered Beluga Whales EERE Success Story-Measuring the Impact of Tidal Power Installations on Endangered Beluga Whales April 9, 2013 - 12:00am Addthis With EERE support, Ocean Renewable Power Company (ORPC) is conducting a two-year study on the effects of tidal turbines on endangered beluga whales in Cook Inlet, Alaska-home to some of the greatest tidal energy potential in the United

  2. MHK Projects/Long Island Sound Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Long Island Sound Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemap...

  3. MHK Projects/San Juan Channel Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Juan Channel Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","...

  4. MHK Projects/San Francisco Bay Tidal Energy Project | Open Energy...

    Open Energy Info (EERE)

    Francisco Bay Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3",...

  5. MHK Projects/Icy Passage Tidal Energy Project | Open Energy Informatio...

    Open Energy Info (EERE)

    Icy Passage Tidal Energy Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","t...

  6. MHK Projects/Ward s Island Tidal Power Project | Open Energy...

    Open Energy Info (EERE)

    s Island Tidal Power Project < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","type"...

  7. MHK Projects/Hammerfest Strom UK Tidal Stream | Open Energy Informatio...

    Open Energy Info (EERE)

    Hammerfest Strom UK Tidal Stream < MHK Projects Jump to: navigation, search << Return to the MHK database homepage Loading map... "minzoom":false,"mappingservice":"googlemaps3","t...

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

    SciTech Connect (OSTI)

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

    2012-02-01

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

  9. EERE Success Story-Measuring the Impact of Tidal Power Installations...

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

    Addthis With EERE support, Ocean Renewable Power Company ... of the greatest tidal energy potential in the United States. ... data at the proposed deployment areas near Fire Island ...

  10. Calming the Waters: The Impact of Turbulence on Tidal Energy Systems

    Office of Energy Efficiency and Renewable Energy (EERE)

    New research is helping the emerging tidal energy industry learn from their counterparts in the wind industry. By considering the effects of atmospheric turbulence when developing turbine designs,...

  11. All Eyes on Eastport: Tidal Energy Project Brings Change, Opportunity to Local Community

    Broader source: Energy.gov [DOE]

    As progress on a Maine-based tidal energy project moves forward, local community member Gerald Morrison reflects on its impact.

  12. Marine Current Turbines Ltd | Open Energy Information

    Open Energy Info (EERE)

    United Kingdom Zip: BS34 8PD Sector: Marine and Hydrokinetic Product: Developer of tidal stream turbine technology for exploiting flowing water in general and tidal streams in...

  13. Mathematical modeling of stormwater pollution in a tidal embayment

    SciTech Connect (OSTI)

    Najjar, K.F.

    1989-01-01

    It has been recognized for many years that stormwater runoff provides a transport mechanism for non-point pollutants into the nation's waterways. As more watershed areas continue to urbanize, greater increases in pollutant loadings will continue to impact the water quality of the receiving water bodies. In many instances, the pollutant impact exceeds the assimilative capacity of the receiving water. To estimate the potential impacts of stormwater pollution, mathematical models are constructed. In this dissertation, mathematical models have been constructed to estimate the non-point pollutant loadings from an urbanizing area as well as to model the assimilative capacity of the receiving tidal embayment system. The models are capable of simulating the hydrologic aspects as well as the water quality cycles of the system as a function of urbanization. In determining the response of the receiving water system to stormwater loadings, the change in receiving water quality is modeled spatially as well as temporally. The overall model is composed of three subsystem models: a stormwater model, a hydrodynamic tidal model, and a receiving water quality model. Construction of the stormwater model is based on STORM (Storage, Treatment, Overflow, Runoff Model) by the US Army Corps of Engineers. A ground water component to the model has been added to adjust the model for application to the study area, Lakes Bay, New Jersey. The tidal model is developed from a pseudo two-dimensional approach. The methodology utilizes the link-node concept to simulate the embayment system. Solutions to equations of motion and continuity are solved using a finite difference method. The receiving water quality model is a two-dimensional time variable water quality model which is based in a finite segment approach.

  14. Current sensor

    DOE Patents [OSTI]

    Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

    2007-01-16

    A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

  15. RED CLUMP STARS IN THE SAGITTARIUS TIDAL STREAMS

    SciTech Connect (OSTI)

    Carrell, Kenneth; Chen Yuqin; Wilhelm, Ronald

    2012-07-15

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

  16. Regional Wave Field Modeling and Array Effects

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

    1C Marine and Hydrokinetic Instrumentation, Measurement & Computer Modeling Workshop - Broomfield, CO July 9 th , 2012 Regional Wave Field Modeling and Array Effects Outline  Overview of SNL's Large-Scale Wave and WEC Array Modeling Activities * WEC Farm Modeling on Roadmap * SNL Current Modeling Capabilities * SNL WEC Farm Model Tool Development WEC Farm Modeling  WEC Farms * Currently focused on improving large scale wave models for environmental assessments WEC Farm Modeling: WEC

  17. Super massive black hole in galactic nuclei with tidal disruption of stars

    SciTech Connect (OSTI)

    Zhong, Shiyan; Berczik, Peter; Spurzem, Rainer

    2014-09-10

    Tidal disruption of stars by super massive central black holes from dense star clusters is modeled by high-accuracy direct N-body simulation. The time evolution of the stellar tidal disruption rate, the effect of tidal disruption on the stellar density profile, and, for the first time, the detailed origin of tidally disrupted stars are carefully examined and compared with classic papers in the field. Up to 128k particles are used in simulation to model the star cluster around a super massive black hole, and we use the particle number and the tidal radius of the black hole as free parameters for a scaling analysis. The transition from full to empty loss-cone is analyzed in our data, and the tidal disruption rate scales with the particle number, N, in the expected way for both cases. For the first time in numerical simulations (under certain conditions) we can support the concept of a critical radius of Frank and Rees, which claims that most stars are tidally accreted on highly eccentric orbits originating from regions far outside the tidal radius. Due to the consumption of stars moving on radial orbits, a velocity anisotropy is found inside the cluster. Finally we estimate the real galactic center based on our simulation results and the scaling analysis.

  18. Enhancing critical current density of cuprate superconductors

    DOE Patents [OSTI]

    Chaudhari, Praveen

    2015-06-16

    The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.

  19. Tidal Energy System for On-Shore Power Generation

    SciTech Connect (OSTI)

    Bruce, Allan J

    2012-06-26

    Addressing the urgent need to develop LCOE competitive renewable energy solutions for US energy security and to replace fossil-fuel generation with the associated benefits to environment impacts including a reduction in CO2 emissions, this Project focused on the advantages of using hydraulic energy transfer (HET) in large-scale Marine Hydrokinetic (MHK) systems for harvesting off-shore tidal energy in US waters. A recent DOE resource assessment, identifies water power resources have a potential to meet 15% of the US electric supply by 2030, with MHK technologies being a major component. The work covered a TRL-4 laboratory proof-in-concept demonstration plus modeling of a 15MW full scale system based on an approach patented by NASA-JPL, in which submerged high-ratio gearboxes and electrical generators in conventional MHK turbine systems are replaced by a submerged hydraulic radial pump coupled to on-shore hydraulic motors driving a generator. The advantages are; first, the mean-time-between-failure (MTBF), or maintenance, can be extended from approximately 1 to 5 years and second, the range of tidal flow speeds which can be efficiently harvested can be extended beyond that of a conventional submerged generator. The approach uses scalable, commercial-off-the-shelf (COTS) components, facilitating scale-up and commercialization. All the objectives of the Project have been successfully met (1) A TRL4 system was designed, constructed and tested. It simulates a tidal energy turbine, with a 2-m diameter blade in up to a 2.9 m/sec flow. The system consists of a drive motor assembly providing appropriate torque and RPM, attached to a radial piston pump. The pump circulates pressurized, environmentally-friendly, HEES hydraulic fluid in a closed loop to an axial piston motor which drives an electrical generator, with a resistive load. The performance of the components, subsystems and system were evaluated during simulated tidal cycles. The pump is contained in a tank for

  20. Deflagration Wave Profiles

    SciTech Connect (OSTI)

    Menikoff, Ralph

    2012-04-03

    Shock initiation in a plastic-bonded explosives (PBX) is due to hot spots. Current reactive burn models are based, at least heuristically, on the ignition and growth concept. The ignition phase occurs when a small localized region of high temperature (or hot spot) burns on a fast time scale. This is followed by a growth phase in which a reactive front spreads out from the hot spot. Propagating reactive fronts are deflagration waves. A key question is the deflagration speed in a PBX compressed and heated by a shock wave that generated the hot spot. Here, the ODEs for a steady deflagration wave profile in a compressible fluid are derived, along with the needed thermodynamic quantities of realistic equations of state corresponding to the reactants and products of a PBX. The properties of the wave profile equations are analyzed and an algorithm is derived for computing the deflagration speed. As an illustrative example, the algorithm is applied to compute the deflagration speed in shock compressed PBX 9501 as a function of shock pressure. The calculated deflagration speed, even at the CJ pressure, is low compared to the detonation speed. The implication of this are briefly discussed.

  1. ocean waves

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

    waves - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear Energy Nuclear

  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.

    1997-08-01

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

  3. DeFrees Large Wave Basin | Open Energy Information

    Open Energy Info (EERE)

    Current Velocity Range(ms) 0.0 Programmable Wavemaking Yes Wavemaking Description Computer controlled 4m hydraulic wave paddle stroke allows a series of solitary waves to be...

  4. 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

    2008-03-17

    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.

  5. Measurement of the rate of stellar tidal disruption flares

    SciTech Connect (OSTI)

    Van Velzen, Sjoert

    2014-09-01

    We report an observational estimate of the rate of stellar tidal disruption flares (TDFs) in inactive galaxies based on a successful search for these events among transients in galaxies using archival Sloan Digital Sky Survey (SDSS) multi-epoch imaging data (Stripe 82). This search yielded 186 nuclear flares in galaxies, 2 of which are excellent TDF candidates. Because of the systematic nature of the search, the very large number of galaxies, the long time of observation, and the fact that non-TDFs were excluded without resorting to assumptions about TDF characteristics, this study provides an unparalleled opportunity to measure the TDF rate. To compute the rate of optical stellar tidal disruption events, we simulate our entire pipeline to obtain the efficiency of detection. The rate depends on the light curves of TDFs, which are presently still poorly constrained. Using only the observed part of the SDSS light curves gives a model-independent upper limit to the optical TDF rate, N-dot <210{sup ?4} yr{sup ?1} galaxy{sup ?1} (90% CL), under the assumption that the SDSS TDFs are representative examples. We develop three empirical models of the light curves based on the two SDSS light curves and two more recent and better-sampled Pan-STARRS TDF light curves, leading to our best estimate of the rate: N-dot {sub TDF}=(1.5--2.0){sub ?1.3}{sup +2.7}10{sup ?5} yr{sup ?1} galaxy{sup ?1}. We explore the modeling uncertainties by considering two theoretically motivated light curve models, as well as two different relationships between black hole mass and galaxy luminosity, and two different treatments of the cutoff in the visibility of TDFs at large M {sub BH}. From this we conclude that these sources of uncertainty are not significantly larger than the statistical ones. Our results are applicable for galaxies hosting black holes with mass in the range of a few 10{sup 6}-10{sup 8} M {sub ?}, and translates to a volumetric TDF rate of (4-8) 10{sup 80.4} yr{sup 1} Mpc

  6. Snohomish PUD No 1 (TRL 7 8 System) - Puget Sound Pilot Tidal...

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

    Ocean Renewable Power Co (ORPC) (TRL 7 8 System) - TidGen (TM) Power System Commercialization Project Sunlight Photonics (TRL 4 System) - Tidal Energy System for On-shore Power ...

  7. EVIDENCE FOR A MILKY WAY TIDAL STREAM REACHING BEYOND 100 kpc

    SciTech Connect (OSTI)

    Drake, A. J.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A.; Donalek, C.; Williams, R.; Catelan, M.; Torrealba, G.; Prieto, J. L.; Larson, S.; Christensen, E.; Beshore, E.

    2013-03-10

    We present the analysis of 1207 RR Lyrae found in photometry taken by the Catalina Survey's Mount Lemmon telescope. By combining accurate distances for these stars with measurements for {approx}14,000 type-ab RR Lyrae from the Catalina Schmidt telescope, we reveal an extended association that reaches Galactocentric distances beyond 100 kpc and overlaps the Sagittarius stream system. This result confirms earlier evidence for the existence of an outer halo tidal stream resulting from a disrupted stellar system. By comparing the RR Lyrae source density with that expected based on halo models, we find the detection has {approx}8{sigma} significance. We investigate the distances, radial velocities, metallicities, and period-amplitude distribution of the RR Lyrae. We find that both radial velocities and distances are inconsistent with current models of the Sagittarius stream. We also find tentative evidence for a division in source metallicities for the most distant sources. Following prior analyses, we compare the locations and distances of the RR Lyrae with photometrically selected candidate horizontal branch stars and find supporting evidence that this structure spans at least 60 Degree-Sign of the sky. We investigate the prospects of an association between the stream and the unusual globular cluster NGC 2419.

  8. Spin Wave Genie

    Energy Science and Technology Software Center (OSTI)

    2015-02-16

    The four-dimensional scattering function S(Q,w) obtained by inelastic neutron scattering measurements provides unique "dynamical fingerprints" of the spin state and interactions present in complex magnetic materials. Extracting this information however is currently a slow and complex process that may take an expert -depending on the complexity of the system- up to several weeks of painstaking work to complete. Spin Wave Genie was created to abstract and automate this process. It strives to both reduce themore » time to complete this analysis and make these calculations more accessible to a broader group of scientists and engineers.« less

  9. Unforced, Forced and Resonance-Forced Waves in a Spherical Atmosphere

    SciTech Connect (OSTI)

    Covey, Curt

    2015-10-27

    This technical report discusses a longstanding issue of atmospheric tides in weather-prediction and general circulation models (GCMs). Tidal signatures consistent with observations have appeared in the surface pressure output of GCMs since their inception (Hardy 1968, Hunt and Manabe 1968). Such models, however, are sufficiently complicated that the possibility of “getting the right answer for the wrong reasons” arises. Lindzen et al. (1968, hereafter LBK) showed that wave reflection at the upper boundary of a GCM can artificially enhance the tides. Covey et al. (2011, 2014) found that tidal output from a number of modern GCMs is surprisingly independent of their forcing. This finding is consistent with earlier suggestions that a compensating effect occurs in some models: lowering the model top reduces the forcing (solar heating of the ozone layer) but also enhances spurious wave reflection (Zwiers and Hamilton 1986, Hamilton et al. 2008).

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

    SciTech Connect (OSTI)

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

    2013-03-01

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